STEUERUNGSEINHEIT.

Hydraulisches Steuersystem für Baumaschinen

Hydraulische Steuervorrichtung für eine Baumaschine

Steuersystem einer Arbeitsmaschine

Ein Steuersystem einer Arbeitsmaschine hat: eine Teilströmungsfluiddruckpumpe, die so aufgebaut ist, dass sie ein Arbeitsfluid von einer ersten Abgabeöffnung und einer zweiten Abgabeöffnung abgibt; ein Kommunikationsschaltventil, das so aufgebaut ist, dass es durch ein Schaltventil geschaltet wird, wenn entweder ein erstes Betätigungsventil oder ein zweites Betätigungsventil so geschaltet wird, dass ermöglicht wird, dass ein erster neutraler Kanal und ein zweiter neutraler Kanal miteinander in Kommunikation stehen; ein Neutralunterbrechungsventil, das so aufgebaut ist, dass es durch das Schaltventil so geschaltet wird, dass eine Kommunikation zwischen einem Tank und entweder dem ersten neutralen Kanal oder dem zweiten neutralen Kanal blockiert wird für das erste Betätigungsventil oder das zweite Betätigungsventil, das nicht geschaltet ist; und eine Abgabeströmungsrateneinstellvorrichtung, die so aufgebaut ist, dass sie die Fluiddruckpumpe so einstellt, dass ihre Abgabeströmungsrate reduziert ...

ANORDNUNG ZUR STEUERUNG EINER HYDRAULISCHEN PUMPE.

Vorrichtung und Verfahren zum Steuern des Motors und der Hydraulikpumpe eines Arbeitsfahrzeugs

Vorrichtung zum Steuern eines Motors und einer Hydraulikpumpe eines Arbeitsfahrzeugs, wobei die Kraft des Motors einen Fahrantriebsstrang und die Hydraulikpumpe antreibt, Antriebsräder durch den Fahrantriebsstrang angetrieben werden, und ein Arbeitsgerät durch die Hydraulikpumpe betätigt wird, und wobei die Vorrichtung Folgendes umfasst: Gasbetätigungsmittel zur Einstellung einer Solldrehzahl des Motors gemäß einem Betriebswert; Motordrehzahleinstellmittel zur Einstellung der Motordrehzahl auf eine geforderte Solldrehzahl; Hydraulikpumpeneinstellmittel zur derartigen Einstellung des Fördervolumens der Hydraulikpumpe, dass ein geforderter Förderstrom erzeugt wird; Beschleunigungserfassungsmittel zur Erkennung, ob der Betriebswert der Gasbetätigungsmittel oder der Motordrehzahl einen vorgeschriebenen Schwellenwert erreicht oder überschreitet; Bremsenbetätigungsmittel zur Einstellung einer Bremskraft für einen Fahrzeugaufbau gemäß einem Betriebswert; Bremsmittel zur Erzeugung der von den Bremsenbetätigungsmitteln ...

Steuerung für die Ölbetriebstemperatur einer hydraulischen Antriebseinrichtung

Eine Steuereinrichtung 12 zum Steuern eines Flussratensteuerventil 11 enthält eine erste Recheneinrichtung zum Bestimmen einer Energiekomponente, die Hydrauliköl erwärmt, eine erste Einstelleinrichtung zum Einstellen eines zweiten Verhältnisses zwischen einer Flussrate durch einen Ölkühler 9 und der Energiekomponente, wie diese gemäß einer experimentell Oder empirisch bekannten eingestellt wird, eines ersten Verhältnisses zwischen der Flussrate durch den Ölkühler 9 und einer Menge einer Wärmestrahlung von dem Ölkühler 9 und wie durch Ersetzen der Menge der Wärmestrahlung von dem Ölkühler 9 in dem ersten Verhältnis zu der Energiekomponente erhalten, und eine zweite Recheneinrichtung zum Bestimmen der Flussrate durch den Ölkühler 9 auf der Grundlage der Energiekomponente, bestimmt durch die erste Recheneinrichtung und das zweite Verhältnis, das durch die erste Einstelleinrichtung eingestellt wird und die eingerichtet ist, um dass Flussratensteuerventil 11 gemäß der Flussrate durch den Ölkühler ...

ZUFUHRSCHALTUNGSVORRICHTUNG FÜR ÖL UNTER DRUCK ZUM HYDRAULISCHEM KOLBEN EINER BAUSTELLENVORRICHTUNG

Hydraulische Anordnung

Es wird eine hydraulische Anordnung (10) zur Erhöhung einer Motorlast beschrieben. Die hydraulische Anordnung umfasst einen hydraulischen Verbraucher (28), eine lastdruckgesteuerte Hydraulikpumpe (24), einen Hydrauliktank (26) und einen mit dem hydraulischen Verbraucher (28) verbundenen hydraulischen Steuerkreis (30), mit welchem ein von der Hydraulikpumpe (24) geförderter Volumenstrom veränderbar ist, wobei der hydraulische Steuerkreis (30) ein Überdruckventil (42) und ein elektronisch ansteuerbares Steuerventil (36) umfasst. Um eine Priorisierung des hydraulischen Verbrauchers bei gleichzeitiger Erhöhung der Motorlast sicherzustellen wird v0) zwischen Überdruckventil (42) und Steuerventil (36) eine lastdruckgesteuerte Druckwaage (38) umfasst.

Hydraulische Antriebseinheit

Strömungsrückgewinnungssystem für Baumaschinen und Baumaschine mit dem System

Method for controlling engine-pump system of hydraulic construction machine

System for automatically controlling an operation of a heavy construction

Hydraulic pressure control device of construction machinery

A hydraulic pressure control device of construction machinery enabling an increase in operability and working efficiency by suppressing a variation in flow rate occurring before and after the switching of a merging-separating valve, an increase in energy efficiency by accurately determining the switching timing of the merging-separating valve to suppress the energy loss of a pressure compensating valve due to pressure loss, and an increase in working efficiency in the compound motion of a plurality of hydraulic actuators. When a controller (14) determines that the necessary flow rates (Q1d, Q2d) of the first and second hydraulic actuators (4, 7) are less than the maximum discharge flow rate (Qmax) of each of the first and second variable displacement hydraulic pumps (2, 3) when the first merging-separating valve (13) and the second merging-separating valve (21) are set to a merging position (A) (When determination in S3 is YES), the switching of the first and second merging-separating valves ...

Flow sensing based variable pump control in a hydraulic system with open centre control valves

A hydraulic system 30 has a variable displacement pump 60 that sends fluid from a tank 61 into a supply conduit 66 from which separate open-centre control valves 51 - 58 convey the fluid to each one of a plurality of hydraulic functions 31 - 38. The control valves 51 58 have open-centre orifices connected in series between a bypass node 90 and the tank 61, thereby forming a bypass passage 83. The pressure at the bypass node 90 controls displacement of the pump 60. A valve arrangement 87, 88, 89 is connected between an outlet 66 of the pump 60 and the bypass node 90 and is responsive to an amount of fluid flow through the supply conduit to the plurality of hydraulic functions 31 38. As the amount of fluid flow increases, the valve arrangement causes fluid flow to the bypass node to decrease. Thus the pressure at the bypass node varies as a function of the operation of the control valves.

Method for controlling hydraulic system for construction machine

Disclosed is a method for controlling a hydraulic system for minimizing a loss of pressure by expanding the open area of a joining spool if a work device such as a boom or the like operates autonomously. The present invention provides a method for controlling a hydraulic system, comprising: a first step for detecting pilot signals according to the operations of operation levers for first and second working devices by first and second pressure-sensing devices and respectively transmitting the pilot signals to a controller; a second step for determining whether the operation lever for the first working device operates autonomously; a third step for supplying second signal pressure by an electronic proportional valve to a joining spool in order to expand the open area of the joining spool with respect to the same operation pressure of the operation lever for the first working device and discharging the operation oil discharged from a second hydraulic pump, in proportion to the operation amount ...

Hydraulic drive system of construction machine

This hydraulic drive system for construction machinery is provided with: a swing motor; a swing operation device that outputs a swing operation signal according to the inclination angle of an operation lever; a swing direction switching valve that includes a spool and a drive unit which receives a command current and drives the spool, and that increases the supply amount of a working fluid to the swing motor and the discharge amount of the working fluid from the swing motor as the command current increases; a control device that supplies, to the swing direction switching valve, a command current that increases as the swing operation signal increases; and a pressure sensor that detects the outflow pressure of the swing motor. When the swing operation signal has decreased, the control device supplies a command current to the swing direction switching valve when the outflow pressure of the swing motor as detected by the pressure sensor increases past a threshold, thereby maintaining the movement ...

Hydraulic system

Hydraulic system

Hydraulic drive system for construction machinery

Hydraulic drive system

A working machine

Closed-loop control of swing

A system (118) and method for controlling the swing of a machine (100) is disclosed. The system (118) may comprise a hydrostatic circuit (120) that includes an electronic displacement control pump (122) and a first swing motor (124a) fluidly connected in a closed loop circuit. The electronic displacement control pump (122) configured to control the supply of fluid to the swing motor (124a) based on a final pump displacement command. The first swing motor (124a) configured to rotate the upper carriage (104) of the machine (100). The hydrostatic circuit (120) configured to control (a) an actual speed of the first swing motor (124a) when the final pump displacement command results from a requested swing motor speed and (b) a torque of the first swing motor (124a) when the final pump displacement command results from a requested swing motor torque.

Control apparatus and method for construction machine

Apparatus for diagnosing failure of hydraulic pump for work machine

SNOW GROOMER AND RELATIVE CONTROL METHOD

A snow groomer (1) having a frame (2); an attachment (8) connected movably to the frame (2); a hydraulic assembly (15) having an actuator (24) for positioning the attachment (8), and a valve (25) for controlling the actuator (24); a variable-flow pump (14) for supplying the hydraulic assembly (15); and a control system (21) for calculating the total flow rate demand of the hydraulic assembly (15), and for controlling the variable- flow pump (14) as a function of the total flow rate demand, so delivery of the variable -flow pump (14) equals the total flow rate demand.

HYDRAULIC BYPASS CIRCUIT FOR A POWER

Disclosed embodiments include hydraulic systems (220; 238; 305) which provide power to lift, tilt and auxiliary (e.g., implement) functions, including high-flow auxiliary functions, with increased efficiency. Disclosed embodiments incorporate a single variable displacement pump (224C; 310) that supplies pressurized fluid to a main control valve (320) (e.g., for lift, tilt, and auxiliary functions) and a bypass circuit (340). The main control valve supplies fluid to control lift, tilt, and auxiliary flow for implements. The bypass circuit combines flow with the output of the auxiliary section of the main control valve to optionally provide high-flow for selected implements. The single variable displacement pump can then be set to different output flow levels, with the bypass circuit functioning differently under different conditions to optimize hydraulic flow to carryout various tasks under various conditions.

CONTROL SYSTEM FOR WORK VEHICLE, METHOD, AND WORK VEHICLE

A control system for a work vehicle comprises a controller. The controller acquires current topography data indicating current topography to be worked. The controller determines, on the basis of the current topography, a target design topography indicating a target trajectory for a work machine. The controller acquires an uneven ground parameter indicating the degree of uneven ground of the current topography. The controller changes the target design topography in accordance with the uneven ground parameter.

HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE

A hydraulic system provided with a relief valve for a construction machine is disclosed, which can reduce a discharge flow rate of a hydraulic pump when a relief valve is operated. The hydraulic system includes an attachment actuator connected to the hydraulic pump to be driven by an operation of the attachment operation device, a control valve installed in a flow path between the hydraulic pump and the attachment actuator, an orifice installed in a flow path branched from a discharge flow path of the hydraulic pump, a relief valve installed on a downstream side of the orifice in the flow path, and a controller outputting a control signal to a flow control valve of the hydraulic pump so as to reduce a discharge flow rate of the hydraulic pump when a difference between pressures before and after the orifice exceeds a predetermined pressure value of the relief valve.

UTILITY VEHICLE HORSEPOWER MANAGEMENT

Disclosed are horsepower management systems and methods for use on power machines (100) with an engine (130) that powers a drive system. An engine speed control device (220) controls the engine speed. A variable displacement drive pump (205) controlled by a displacement control member (215) provides pressurized fluid to a drive motor (214). A control system (200) communicates with the engine speed control device and the pump displacement control member. The control system includes a user input device (230) and a command lever (210) rotatably coupled to the displacement control member and capable of receiving the user input. The command lever provides a signal to the engine speed control device in response to the user input. The command lever also commands a given displacement via the displacement control member subject to load forces on the hydrostatic pump transmitted to a limiting mechanism (240) coupled to the command lever and the displacement control member (215).

METHOD AND DEVICE FOR CONTROLLING A CONSTRUCTION MACHINE

A signal sending device 21 which stores therein proper data, such as an acce lerator position and a pump output, concerning operating conditions, such as supply hydraulic pressure and flow rate, appropriate for a working attachment to be attached to the front part of a hydraulic excavator or the like is mounted on the working attachment. The body of a hydraulic ex cavator is provided with a controller 11 adapted to control the hydraulic sources by receiving a nd storing proper data sent from the signal sending device 21. The signal sending device 21 include s a ROM 31 for storing proper data for each working attachment, a CPU 32 for retrieving proper data from the ROM 31, and a data communication interface (COM) 33 for receiving command signals se nt from the controller 11 of a machine body to the CPU 32 and sending to the controller 11 proper data which have been retrieved from ROM 31 by the CPU 32.

Controller for drive system of work machine, has control level for responding to changes in power demand on secondary drive by changing manipulated variable of secondary drive of drive system, and secondary drive is driven by primary drive

The controller has a control level for responding to the changes in the power demand on a secondary drive by changing the manipulated variable of the secondary drive of a drive system. The secondary drive is driven by a primary drive. The fuel injection quantity of an internal combustion engine (5) is adjusted by an engine control function based on the difference between a target speed and an actual rotational speed. The fuel injection quantity is adjusted as a function of control signals of the secondary drive. An independent claim is included for a method for controlling a drive system of a work machine.

Hybrid construction machine

Provided is a hybrid construction machine (driving the upper swing structure (20) using a hydraulic motor (27) and an electric motor (25) together) capable of regenerating the energy of the upper swing structure (20) in deceleration or stopping into electric power and using the regenerated electric power for assisting the driving of the upper swing structure (20), while also being capable of securing satisfactory operational feeling and operation capability even when the electric motor (25) does not operate. When the electric motor (25) is not driven, a controller (51) controls a hydraulic circuit system (40) (specifically, a swing direction/flow rate control valve (42), a center bypass cut valve and a regulator) so as to increase output torque of the hydraulic motor (27) by an amount corresponding to torque to be compensated for the non-driving of the electric motor (25) compared to cases where the electric motor (25) is driven.

CONSTRUCTION MACHINERY

Hydraulic drive device for construction machinery

The control method of an excavator and excavators

Variable load sense open center hybrid system

Used in the hydraulic system of construction machinery

Working machine

Work machine having an attachment device, in particular a trench cutter, and attachment device, in particular a trench cutter

L'invention porte sur une machine de travail, de préférence une machine de travail mobile, avec un appareil accessoire, notamment une fraise pour parois moulées, l'appareil accessoire comprenant au moins deux moteurs hydrauliques (31) réglables pour entraîner des charges indépendantes adaptées pour pouvoir être commandées individuellement, l'alimentation hydraulique des moteurs hydrauliques (31) réglables étant effectuée par un groupe d'entraînement hydraulique (20, 21) disposé à l'extérieur de l'appareil accessoire, notamment un groupe d'entraînement de la machine de travail, lesdits au moins deux moteurs hydrauliques (31) réglables de l'appareil accessoire étant reliés à un réseau à pression constante mis à disposition par le groupe d'entraînement hydraulique (20, 21).

HYDRAULIC DRIVE FOR HYDRAULIC WORK MACHINE

건설 기계

... 용량 레귤레이터(26)와 압력 제어 밸브(44)의 사이에는 제어압 전환 밸브(57)를 설치한다. 이 제어압 전환 밸브(57)는, 압력 제어 밸브(44)로부터 로드 센싱용 제어압(PLS)이 용량 레귤레이터(26)로 출력되는 것을 허용하는 제어 위치(j)와, 용량 레귤레이터(26)로 출력되는 로드 센싱용 제어압(PLS)을 소정의 저압값까지 저하시키는 제어 해제 위치(k)로 전환한다. 컨트롤러(61)는, 필터(19)의 재생이 필요하다고 판정했을 때, 제어압 전환 밸브(57)를 제어 해제 위치(k)로 전환한다. 용량 레귤레이터(26)는, 제어압 전환 밸브(57)가 제어 해제 위치(k)로 전환되어 로드 센싱용 제어압(PLS)이 상기 저압값까지 저하했을 때, 유압 펌프(13)의 토출 용량을 증대시켜 엔진(10)의 회전 부하를 높인다.

DRIVE CONTROL METHOD FOR OPERATING MACHINE

작업 기계의 유압 제어 장치

... 본 발명은 연동에 의한 유압 액추에이터의 속도 저하를 경감하면서, 분류에 의한 손실을 저감한다. 제1 유압 액추에이터(6)와, 한쪽의 유압 펌프(20a)와, 제2 유압 액추에이터(7)와, 다른 쪽의 유압 펌프(20c)를 구비하고, 제1 유압 액추에이터(6) 및 제2 유압 액추에이터(7)의 동작 지시가 나와 있는 것을 검출하는 동작 지시 검출 수단(101-104)과, 제1 유압 액추에이터(6) 및 제2 유압 액추에이터(7)의 동작 지시량에 따라, 한쪽의 유압 펌프(20a)의 토출 유량과 다른 쪽의 유압 펌프(20c)의 토출 유량을 각각 개별로 조절 가능한 펌프 유량 제어 수단(100)을 구비하고, 펌프 유량 제어 수단(100)은 제1 유압 액추에이터(6)와 제2 유압 액추에이터(7)가 동시에 작동하고 있는 경우, 제1 유압 액추에이터(6)가 작동하고 제2 유압 액추에이터(7)가 작동하고 있지 않은 경우보다도 한쪽의 유압 펌프(20a)의 토출 유량을 증가시킨다.

건설기계의 유압 구동 장치

... 타방의 유압 펌프의 흡수 토크를 순유압적인 구성에서 양호한 정밀도로 검출하여 일방의 유압 펌프측에 피드백함으로써, 전체 토크 제어를 양호한 정밀도로 행하고, 원동기의 정격 출력 토크를 유효 이용할 수 있도록 한다. 이 목적을 위해, 메인 펌프(202)의 토출압과 로드 센싱 구동 압력이 유도되고, 메인 펌프(202)의 흡수 토크를 모의한 특성이 되도록 메인 펌프(202)의 토출압을 보정하여 출력하는 토크 피드백 회로(112v)와, 이 토크 피드백 회로의 출력압이 유도되고, 이 출력압이 높아짐에 따라 메인 펌프(102)의 토출 유량을 감소시켜 최대 토크(T12max)가 감소하도록 메인 펌프(102)의 토출 유량을 제어하는 토크 피드백 피스톤(112f)을 설치한다. 토크 피드백 회로(112v)는 제 1 및 제 2 가변 감압 밸브(112g, 112q)를 가지고 있다.

APPARATUS AND METHOD FOR CONTROLLING A HYDRAULIC PUMP OF A CONSTRUCTION MACHINE

The present invention relates to an apparatus and method for controlling a hydraulic pump of a construction machine. The disclosed apparatus of the present invention comprises: a pump control unit which controls a discharge pressure of the hydraulic pump driven by an engine, wherein the pump control unit includes a set pressure value calculation unit which calculates a set pressure value on the basis of an engine output torque estimation value or an engine RPM; and a failure- handling unit which selects either the set pressure value and a pressure instruction value in accordance with whether or not failures of a swash plate angle sensor have occurred, and outputs the selected value. According to the present invention, the set pressure value is calculated on the basis of the engine output torque estimation value, and the pump is controlled in accordance with the calculated set pressure value. Thus, it is possible to prevent a suction torque value of the pump from exceeding the maximum torque ...

작업 기계의 유압 제어 장치

... 블리드 오프 제어에 의한 유압 펌프의 토출 유량의 스로틀 오프의 손실을 저감시켜, 에너지 효율을 향상시킴과 함께, 유압 펌프의 토출 압력을 조작 레버 장치의 조작량에 따라 제어 가능하게 하고, 조작 성능도 향상시킨다. 컨트롤러(6)는 조작량 검출기(20A, 20B)로부터의 조작량 신호에 기초하여, 조작량 신호가 증가하는 것에 따라서 증가하는 목표 펌프 토출 압력을 산출하는 목표 펌프 압력 설정부(32)와, 조작량 신호에 기초하여, 조작량 신호가 증가하는 것에 따라서 증가하는 펌프 유량 상한값을 산출하는 펌프 유량 상한 설정부(33)를 갖고, 목표 펌프 압력 설정부(32)에서 산출한 목표 펌프 토출 압력과, 펌프 유량 상한 설정부(33)에서 산출한 펌프 유량 상한값과, 압력 검출기(21)에서 검출한 유압 펌프(2)의 토출 압력에 기초하여 유압 펌프(2)의 틸팅량이 제어된다.

APPARATUS FOR CONTROLLING THE ROTATION FREQUENCY OF A MOTOR OF A HYDRAULIC CONSTRUCTION MACHINE HAVING AN EXCAVATION STATE JUDGING UNIT

PURPOSE: An apparatus for controlling the rotation frequency of a motor of a hydraulic construction machine is provided to improve workability and operationality by accurately confirming an excavated state. CONSTITUTION: An apparatus for controlling the rotation speed of a motor of a hydraulic construction machine comprises a variable capacitance hydraulic pump, multiple hydraulic actuators, control valves, an operation order unit, an operation order detection unit, a pump pressure detection unit, a standard target rotational frequency setting unit, an excavation state judging unit, and a target rotational frequency compensation unit. The variable capacitance hydraulic pump is powered by an engine. The hydraulic actuators are powered by the pressure oil of hydraulic pumps. The control valves control the flow rate and direction of the pressure oil flowing from the hydraulic pumps to the hydraulic actuators. The operation order unit orders the operation of the hydraulic actuators. The operation ...

Control system and method of Hydraulic Pump for Construction Machinery

CONTROL DEVICE FOR HYBRID CONSTRUCTION MACHINE

ANORDNING FOR MANOVRERING AV EN DIESELHYDRAULISK DRIFT

METHOD FOR STARTING AN ELECTRIC MOTOR IN A HYDRAULICALLY OPERATED WORKING MACHINE

The invention relates to a method for starting at least one asynchronous electric motor of a large hydraulic excavator having a service weight > 100 t and having an electrohydraulic drive, in that the particular electric motor is transferred from an idle position to an operating position by using a three-stage motor starting process, wherein the volumetric flow rate of at least one hydraulic pump operatively connected to the electric motor is set to the delivery rate V = 0 during all starting stages of the electric motor and the delivery rate V of the hydraulic pump is controlled to a value > 0 only after the last starting stage of the electric motor by activating an actuator.

CLOSED LOOP DRIVE CIRCUIT WITH EXTERNAL BRAKE ASSIST

A hydrostatic drive system for a vehicle (10) comprises an open circuit (100), a closed travel circuit (120), an electronic controller (320), and a main variable displacement hydraulic pump (102) driven by an internal combustion engine (12) equipped with a speed sensor (350). The main variable displacement hydraulic pump may be configured to supply hydraulic fluid to a hydraulic consumer (34, 44, 50) via a hydraulic supply line (106). A pressure relief valve (118) may be connected to a reservoir (300) and may be permanently connected to the hydraulic supply line of the open circuit. The electronic controller may be configured to run a strong braking mode in which the electronic controller at least partially increases the displacement of the main variable displacement hydraulic pump such that hydraulic fluid is discharged via the permanently connected pressure relief valve into the reservoir if the sensed engine speed is higher than a predetermined maximum engine speed.

HYDRAULIC SYSTEM FOR HYDRAULIC WORKING MACHINE

... [Problem] To provide a hydraulic system for a hydraulic working machine, the hydraulic system being configured so that the influence of the impairment of the responsiveness to the control of the speed of an actuator is reduced to a minimum level to enable the hydraulic system to have satisfactory operability equivalent to the operability of a spool-type flow rate control valve. [Solution] The present hydraulic system for a hydraulic shovel is configured so that rotational power is inputted from a rotational power generation means (11) into a hydraulic pump (12) to generate hydraulic power and an actuator (14) is operated by the hydraulic power. The hydraulic system is configured so as to comprise a recovery ratio control means for branching a hydraulic oil discharge oil path (20), which is from the actuator (14), into a flow rate control oil path (21) which is an oil path connecting to the spool of a flow rate control valve (19) controlled by lever operation and into a power recovery oil ...

APPARATUS AND METHOD FOR CONTROLLING A HYDRAULIC PUMP OF A CONSTRUCTION MACHINE

The present invention relates to an apparatus and method for controlling a hydraulic pump of a construction machine. The disclosed apparatus of the present invention comprises: a pump control unit which controls a discharge pressure of the hydraulic pump driven by an engine, wherein the pump control unit includes a set pressure value calculation unit which calculates a set pressure value on the basis of an engine output torque estimation value or an engine RPM; and a failure- handling unit which selects either the set pressure value and a pressure instruction value in accordance with whether or not failures of a swash plate angle sensor have occurred, and outputs the selected value. According to the present invention, the set pressure value is calculated on the basis of the engine output torque estimation value, and the pump is controlled in accordance with the calculated set pressure value. Thus, it is possible to prevent a suction torque value of the pump from exceeding the maximum torque ...

METHOD FOR CONTROLLING HYDRAULIC PUMP IN EXCAVATOR

The present invention relates to a method for controlling a hydraulic pump in an excavator, and more particularly, to a method for controlling a hydraulic pump in an excavator for actuating an engine at the best engine revolution speed so as to achieve optimum fuel economy when the hydraulic pump discharges a set flow that is predetermined using an instrument panel by an operator, when carrying out optional operations, such as using the breaker or the crusher of the excavator, thereby enabling optimum control of the engine and the pump.

HYDRAULIC SYSTEM FOR CONSTRUCTION MACHINE INCLUDING EMERGENCY CONTROL UNIT FOR ELECTRIC HYDRAULIC PUMP

The present invention relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily operating the construction machine when an electric unit for controlling the electric hydraulic pump fails to operate. To this end, disclosed is the hydraulic system comprising the electric hydraulic pump, the electric control unit for controlling the electric hydraulic pump, and the emergency control unit, which operates when the electric control unit fails to operate, so as to temporarily control the electric hydraulic pump in accordance with to a pre-set condition, which can effectively respond to a low load work corresponding to a predetermined pressure (P1) and to a high load work corresponding to a higher pressure (P2), by the emergency control unit operating according to different optional conditions, based on the load (low load, high load) of the working machine that ...

HYDRAULIC DRIVE FOR HYDRAULIC WORK MACHINE

When a control lever (8) is operated to leftward under a heavy load, a pressure sensor (11) detects a pressure to a direction switching valve (1), pressure sensors (9, 10) detect pressures on upstream and downstream and sides of a throttle valve (4), and an inclination angle sensor (15) and a revolution counter (16) detect an inclination angle of a swash plate and the number of revolutions of a pump (2), the detected pressures, angle and rotations being input to a controller (12). A target flow rate setting unit for lifting of a boom determines a target flow rate for lifting of a boom on the basis of signals from the pressure sensor (11) and the revolution counter (16), a detecting unit of a discharge flow rate of a pump determines a discharge flow rate of a pump on the basis of signals from the inclination angle sensor (15) and the revolution counter (16), and a differential pressure detecting unit and a center bypass flow rate computing unit determine a center bypass flow rate on the ...

PROCESS AND COMPOSITION FOR PURIFYING SEMICONDUCTOR PROCESS GASES TO REMOVE LEWIS ACID AND OXIDANT IMPURITIES THEREFROM

Scavenger compositions useful for purifying process gas streams, such as hydrogen, nitrogen, noble gases, diborane, and hydride gases from Groups IVA-VIA of the Periodic Table, such as arsine, phosphine, silane, germane, hydrogen selenide, and hydrogen telluride, and mixtures thereof, to remove water, oxygen, and other oxidant and Lewis acid impurities therefrom, such scavenger comprising a porous, high surface area inert support having thereon an active scavenging species, formed by the deposition on the support of a Group IA metal and pyrolysis thereof at a selected elevated temperature on said support.

HYDRAULIC WORKING MACHINE

A hydraulic circuit of a hydraulic working machine is constituted of the following components: a main pump (21), a boom cylinder (11) telescoped by pressurized oil from the main pump (21), a directional control valve (22) for regulating the flow of the pressurized oil fed from the main pump (21) to a bottom chamber (11a) of and a rod chamber (11b) of the boom cylinder (11), an operating device (23) for switching the directional control valve (22), a pilot pump (24), a jack-up switch valve (25) for regulating the flow of pressurized oil discharged from the pilot pump (24), a flow-rate control valve (26) connected, on the upstream side of the directional control valve (22), to a meter-in port of the directional control valve (22) and switched by the jack-up switch valve (25), and a center bypass switch valve (27) connected, on the downstream side of the directional control valve (22), to a center bypass port of the directional control valve (22) and switched by the jack-up switch valve (25 ...

Control arrangement and method for activating a plurality of hydraulic consumers

A control arrangement for supplying pressure medium to a plurality of consumers. A supply metering orifice and an individual pressure compensator are associated with each consumer of the plurality of consumers. The individual pressure compensator is adjusted via a central control unit.

Hydraulic control device for working machine

A hydraulic control device for a working machine includes hydraulic actuators, a hydraulic pump which functions as a hydraulic power source, control valves which control the actuators on the basis of operations by an operating unit, a common bleed-off valve which returns excess oil to a tank via an unload passage on the basis of the operations by the operating unit, and a control unit which controls the common bleed-off valve. The common bleed-off valve is capable of setting a position for closing the unload passage when the common bleed-off valve is in a non-operating state. The control valves have center bypass passages which function as individual bleed-off passages which open when the control valves are in neutral states. Opening characteristics of the control valves are set such that the center bypass passages are closed in initial stroke periods in which the control valves move toward operating positions.

Method of controlling speed change of hydraulic drive device for vehicle and speed change device

The present invention relates to a method of controlling a speed change of a hydraulic driving apparatus for a vehicle and to a speed changing device which provide excellent traveling efficiency and controllability. To this end, the method of controlling a speed change comprises discriminating between at least a powering travel and a braking travel from an accelerating amount (θ) and rotational speed of a hydraulic motor (50) for controlling. At the time of the powering travel, a directional control valve (21) can be fully opened in response to the rotational speed (ωout) of the hydraulic motor (50) and the accelerating amount (θ). In addition, the speed changing device comprises an accelerating amount detection sensor (61a), a motor rotational speed sensor (52) for detecting a vehicle speed (V), and a control device (60) for discriminating, from the accelerating amount (θ) and the vehicle speed (V), between the powering travel and the braking travel for providing a control.

Load sensing control system for hydraulic machine

A load sensing control system for a hydraulic machine sets a variable target differential pressure between a delivery pump pressure and a load pressure of an actuator. A control factor is determined that becomes larger as the deviation between the target differential pressure and the actual differential pressure is increased, and that becomes smaller as the differential pressure deviation is decreased. The control factor also becomes larger as the target differential pressure becomes smaller. The target displacement volume for the hydraulic pump is based on the differential pressure deviation, which is calculated from the target differential pressure and the control factor.

Failure detection system for hydraulic pumps

A failure detection system for hydraulic pumps each having displacement varying means. The system includes displacement command generating means for generating a command value for causing the displacement varying means of one of the pumps to be displaced a predetermined amount, sensor means for sensing the amount of a displacement of the displacement varying means, comparator means for comparing the absolute value of the difference between a command value generated by the displacement command generating means and the amount of the displacement sensed by the sensor means with a predetermined allowable value, and output means for outputting a failure signal for indicating that the pump is out of order when it is found by the comparator means that the allowable value has been exceeded by the absolute value.

Hydraulic control device of a working machine

A hydraulic control apparatus for a working machine in which a flow rate and a direction of pressure oil discharged from a hydraulic pump are controlled by a control valve to supply it to a swing motor, comprising: a bleed-off oil path for bleeding off a part of the pressure oil supplied to the swing motor, a cut valve provided on the bleed-off oil path to adjust a bleed-off amount, a controller for controlling the cut valve through a solenoid proportional valve, and pressure sensors for detecting an operating amount of a remote control valve for swing, characterized in that the controller sets the bleed-off amount according to the operating amount detected by the pressure sensors, controls an opening area of the cut valve on the basis of the bleed-off amount set, and suppresses the shock when sudden swinging operation takes place.

Working machine

A working machine is disclosed. A boom supports an arm. An upper revolving body supports the boom. A lower traveling body mounts the upper revolving body in a rotatable state. A hydraulic actuator drives a hydraulic oil while relieving the hydraulic oil. A first pump supplies the hydraulic oil to the hydraulic actuator. A pump state detector detects load of the first pump. A controller reduces a flow rate of the hydraulic oil from the first pump to the hydraulic actuator when the pump state detector detects a predetermined state.

Fluid pressure circuit

A fluid pressure circuit that can, in either case where a first actuator that is fed from a first pump or a second actuator that is fed from a second pump is operated, by allowing feeding of the hydraulic fluid to a specific actuator from either the first or second pump, improve interlockability with the specific actuator. A control valve is incorporated with a plurality of first-group spools fed from a drive pump and a plurality of second-group spools fed from an idle pump. A solenoid selector valve unit switches a pilot line of a second-group tool controlling spool to a communicating state at the time of detection of a spool operation by a first pressure switch and switches a pilot line of a first-group tool controlling spool to a communicating state at the time of detection of a spool operation by a second pressure switch.

Hydraulic system having dual tilt blade control

A hydraulic system for a machine is disclosed. The hydraulic system may have a tank configured to hold a supply of fluid, a pump configured to draw fluid from the tank and pressurize the fluid, a first cylinder operatively connected between a first side of a work tool and an undercarriage of the machine, and a second cylinder operatively connected between a second side of the work tool and the undercarriage of the machine. The hydraulic system may also have a first electro-hydraulic valve associated with the first cylinder and configured to selectively regulate a flow of pressurized fluid to the first cylinder independently of the second cylinder, and a second electro-hydraulic valve associated with the second cylinder and configured to selectively regulate a flow of pressurized fluid to the second cylinder independently of the first cylinder.

Engine assist by recovering swing kinetic energy

An energy recovery system for a machine having a movable work tool, a swing motor to swing the work tool about a vertical axis, a pump providing pressurized fluid to the swing motor, a power source outputting power to drive the pump, and a controller. The energy recovery system may include a first accumulator, a swing charge valve selectively connecting the swing motor to the first accumulator, an assist motor operatively connected to the power source, and a discharge selectively connecting the first accumulator to the assist motor. The swing charge valve may fluidly connect the swing motor to the first accumulator when fluid pressure from the swing motor is greater than a charge set pressure. The controller may cause the discharge valve to fluidly connect the first accumulator with the assist motor when the power demand on the power source is greater than a minimum assisted power demand.

Hydraulic system and method for control

A hydraulic system is disclosed having at least two hydraulic circuits. The disclosed system apportions flow between the two hydraulic circuits based on an assumed flow rate that is held constant in both power-limited and non-power-limited conditions.

SHOVEL

A shovel (100) according to embodiments of the present invention includes a lower travelling body (1), an upper pivot body (3) pivotably mounted to the lower travelling body (1), an excavation attachment (AT) rotatably mounted to the upper pivot body, and a controller (30) provided to the upper pivot body (3). The controller (30) is configured to autonomously perform a compound operation including an operation of the excavation attachment (AT) and a pivot operation. The controller (30) may be configured to, in response to an automatic switch (NS2) provided in a cabin (10) mounted to the upper pivot body (3) being operated, autonomously perform the compound operation.

HYDRAULIC SYSTEM HAVING DUAL TILT BLADE CONTROL

A hydraulic system for a machine is disclosed. The hydraulic system may have a tank configured to hold a supply of fluid, a pump configured to draw fluid from the tank and pressurize the fluid, a first cylinder operatively connected between a first side of a work tool and an undercarriage of the machine, and a second cylinder operatively connected between a second side of the work tool and the undercarriage of the machine. The hydraulic system may also have a first electro-hydraulic valve associated with the first cylinder and configured to selectively regulate a flow of pressurized fluid to the first cylinder independently of the second cylinder, and a second electro-hydraulic valve associated with the second cylinder and configured to selectively regulate a flow of pressurized fluid to the second cylinder independently of the first cylinder.

Hydraulic system for working machine

A hydraulic system for a working vehicle includes a first hydraulic pump to deliver pilot fluid to a control valve for a hydraulic actuator whose highest load pressure acts on a first fluid passage, and a second hydraulic pump to deliver hydraulic fluid whose pressure acts on a second fluid passage. A hydraulic controller is operable to control a load-sensing (LS) differential pressure between the highest load pressure and a delivery pressure of the hydraulic fluid from the second hydraulic pump. A third fluid passage to which the second hydraulic pump delivers the hydraulic fluid branches to a fourth fluid passage for flow of the pilot fluid. A solenoid valve is operable to change a pilot pressure of the pilot fluid for the hydraulic controller, and a controller is configured or programmed to control the solenoid valve to adjust the pilot pressure to change the LS differential pressure.

Pump failure alarm system for hydraulic working machine

A pump failure alarm system which is provided in a hydraulic working machine comprising hydraulic pumps (1A, 1B) driven by a prime mover, delivery lines (4A, 4B) joining with one another into one common delivery line (3) on the downstream side, check valves (6A, 6B) provided in the delivery lines upstream of a point where the delivery lines join with one another, a hydraulic cylinder (10) driven by a hydraulic fluid introduced through the common delivery line, and a hydraulic reservoir (14). The pump failure alarm system comprises pressure sensors (33A, 33B) for detecting respective delivery pressures of the hydraulic pumps, bypass lines (35A, 35B) having one ends connected to the delivery lines at points upstream of the check valves and the other ends connected to the hydraulic reservoir, solenoid switching valves (38A, 38B) for opening and closing the associated bypass lines, an alarm display unit (40) for giving an alarm in correspondence to each of the hydraulic pumps, and a controller ...

OPERATION CONTROLLER

Operation controller for actuators The ratio of the operation quantities to the drive quantity command values is changed depending upon an operation mode flow rate data (41) and the drive quantity command values are individually weighted for the same quantity of the manipulated variable depending upon a priority mode weight data (42). At least two energy sources (FR,PR) are provided as an energy source for driving the actuators, and the timing and the amount for supplying energy from the energy source are separately controlled depending upon a pump utilisation data (43) and a tilted pump plate control data (44). These control data are suitably calculated and determined (inclusive of look-up table processing) each time depending upon the operation mode of the operators and the selection mode of operation mode selecting switch (21) and priority mode selecting switch (22).

HYDRAULIC CIRCUIT FOR A SWING SYSTEM IN A MACHINE

CONTROL APPARATUS FOR CONSTRUCTION MACHINERY

PROBLEM TO BE SOLVED: To provide a control apparatus for construction machinery, which suppresses loss of an engine output by controlling the flow rate of a pump so as not to excessively increase pump delivery pressure at the time of leveling work, to thereby prevent lowering of fuel economy. SOLUTION: The control apparatus for construction machinery comprises hydraulic pumps 51, 52, a plurality of operating members 54, and a control means 1 for controlling flow rates of discharge from the hydraulic pumps 51, 52. The control means 1 includes a boom fine operation determining means 2 for determining whether or not a boom fine operation is carried out based on a manipulated variable of a boom operating member 54a, a stick fine operation-determining means 3 for determining whether or not a stick minute operation is carried out based on a manipulated variable of a stick operating member 54b, a bucket minute operation determining means 4 for determining whether or not a bucket fine operation ...

APPARATUS FOR PREVENTING LAG-DOWN OF ENGINE FOR CONSTRUCTION MACHINE

PROBLEM TO BE SOLVED: To provide an apparatus for preventing the lag-down of an engine for a construction machine which can carry out the more accurate control of pump torque when an operation apparatus has been operated from a non-operated state where the rotational speed of the engine is held at a required low speed. SOLUTION: The apparatus for preventing the lag-down of the engine for the construction machine comprises a vehicle body controller 13 and an electromagnetic valve 16, etc., the vehicle body controller 13 makes the pump torque a small value Tp1 corresponding to a low rotational speed n1 in the case of a non-operated state where an engine rotational speed is controlled at the required low rotational speed n1, and composes a torque control means for controlling a torque control valve 7 so as to continually hold the pump torque to be the small value Tp1 for a required holding time T when an operating apparatus 5 has been operated from a non-operated state. In addition, the holding ...

HYDRAULIC DRIVE UNIT AND WORKING MACHINE PROVIDED THEREWITH

PROBLEM TO BE SOLVED: To provide a hydraulic drive unit and a working machine provided therewith, effectively utilizing return oil while maintaining the driving speed of a hydraulic actuator. SOLUTION: A controller 15 specifies based on power required for a hydraulic pump 17, a regenerative flow rate introduced to a regenerative oil passage 28 and an excess flow rate other than the regenerative flow rate, among return oil other than oil introduced to a tank B1 through a control valve 24 during an external force applying period when pressure P2 of return oil exceeds discharge pressure P1 of the hydraulic pump 17, and controls an MO valve (meter-out valve) 21 and a regulator 23 so that the regenerative flow rate of the return oil is introduced to the regenerative oil passage 28 and the excess flow rate of the return oil is introduced to an oil lead-out passage 20. COPYRIGHT: (C)2008,JPO&INPIT ...

РАБОЧАЯ МАШИНА С ГИДРАВЛИКОЙ ДЛЯ РЕКУПЕРАЦИИ ЭНЕРГИИ

Изобретение может быть использовано в рабочих машинах с по меньшей мере одним гидравлическим исполнительным элементом для приведения в действие рабочего оборудования. Рабочая машина имеет по меньшей мере один гидравлический исполнительный элемент (80) для приведения в действие рабочего оборудования, гидравлические потребители (100), (110), два приводимых в движение приводным агрегатом (10) рабочей машины вытеснительных узла (20), (30), и блок (90) управления. Первый вытеснительный узел (20) питает блок (90) управления гидравлической средой из гидравлического бака. Второй вытеснительный узел (30) в рабочем режиме питает блок (90) управления гидравлической средой из гидравлического бака и во время режима рекуперации является приводимым в движение гидравлическим объемом, вытесненным указанным по меньшей мере одним гидравлическим исполнительным элементом (80) или гидравлическим потребителем (100), (110), чтобы запитывать кинетическую энергию обратно в приводной агрегат (10). Блок (90) управления ...

СИСТЕМА ГИДРОУПРАВЛЕНИЯ С КОМПЕНСАЦИЕЙ ГИДРОДИНАМИЧЕСКОЙ СИЛЫ

Раскрывается система гидроуправления (28) для машины (10). Система гидроуправления может включать в себя насос (38), гидрораспределитель (58) управления производительностью насоса, а также регулирующий гидрораспределитель (68) рабочего органа, выполненный с возможностью получения жидкости под давлением из насоса и выборочного направления жидкости под давлением на гидродвигатель. Система включает в себя контроллер (34), связанный с гидрораспределителем управления производительностью. Контроллер может быть выполнен с возможностью определения перепада давления в регулирующем гидрораспределителе рабочего органа, по существу, отличающегося от расчетного перепада давления, определения желаемого положения гидрораспределителя управления производительностью на основании перепада давления, а также определения гидродинамической силы, воздействующей на гидрораспределитель управления производительностью, на основании желаемого положения. Контроллер может быть дополнительно выполнен с возможностью формирования ...

WENIGSTENS ZWEI HYDRAULISCHEN VERBRAUCHERN

Hydraulikmanagement für begrenzte Geräte von Baumaschinen

Maschinensteuerung (50) zum Bereitstellen von Hydraulikventil-Betätigungsbefehlen zum Steuern einer Durchflussmenge eines Hydraulikfluids zu zwei oder mehr einer Maschine (10, 70) zugeordneten Aktuatoren (84), wobei die Steuerung (50) enthält: eine Steuereingabe (102) zum Entgegennehmen von Bedienerbefehlen zur Steuerung der zwei oder mehr Aktuatoren (84), ein Umwandlungsmodul (103) zum Umwandeln der Bedienerbefehle in einen ersten und zweiten Ventilsteuerbefehl (104), und ein Korrigiermodul (106) zum Korrigieren des ersten und zweiten Ventilsteuerbefehls (104), so dass ein entsprechender erster und zweiter korrigierter Ventilsteuerbefehl (108) erzeugt wird, wobei der erste korrigierte Ventilsteuerbefehl der geringere von dem ersten Ventilsteuerbefehl und einer Threshold-Funktion (304) der Maschinenmotordrehzahl ist, wenn eine maximal verfügbare Durchflussmenge (303) zum Ausführen des ersten und zweiten Ventilsteuerbefehls (104) nicht ausreichend ist und die Differenz von der maximal verfügbaren ...

ARBEITSMASCHINE UND STEUERUNGSVERFAHREN FÜR ARBEITSMASCHINE

Eine Arbeitsmaschine gemäß einem Aspekt enthält eine Arbeitsausrüstung, eine Betätigungsvorrichtung zum Betätigen der Arbeitsausrüstung sowie eine Steuervorrichtung zum Steuern der Arbeitsausrüstung. Die Steuervorrichtung führt Eingriffs-Steuerung zum Anheben der Arbeitsausrüstung auf Basis eines Betätigungs-Befehls von der Betätigungsvorrichtung durch, entscheidet über Umschalten von der Eingriffs-Steuerung auf Steuerung der Arbeitsausrüstung entsprechend einem Betätigungs-Befehl von der Betätigungsvorrichtung, bestimmt, ob der Betätigungs-Befehl von der Betätigungsvorrichtung für das Umschalten, das auf Basis eines Ergebnisses der Entscheidung durchgeführt wird, ein Betätigungs-Befehl zum Anheben der Arbeitsausrüstung oder ein neutraler Befehl ist, bestimmt eine Geschwindigkeitsdifferenz zwischen einer Soll-Geschwindigkeit beim Anheben der Arbeitsausrüstung bei der Eingriffs-Steuerung und einer Soll-Geschwindigkeit entsprechend dem Betätigungs-Befehl von der Betätigungsvorrichtung, wenn ...

HYDRAULISCHES STEUERUNGSSYSTEM FÜR ERDBAUMASCHINE

VERFAHREN UND VORRICHTUNG ZUM ANTRIEB EINER HYDRAULISCHEN VORRICHTUNG

Baggersteuerung zur Lastlieferung

Ein Motor an einem Bagger liefert die für den Betrieb einer Hydraulikpumpe erforderliche Energie, um unter Druck stehende Hydraulikflüssigkeit zu einem Hydraulikaktuator zu pumpen. Der Hydraulikaktuator wird so gesteuert, dass er eine Last an dem Motor aufbringt. Die Reaktion des Motors auf die vom Hydraulikaktuator aufgebracht Last, wird erfasst und protokolliert. Auf die protokollierten Daten zur Motorreaktion kann zugegriffen werden, um die Motorreaktion zu bestimmen.

Arbeitsmaschine mit Hydraulik zur Energierekuperation

Die vorliegende Erfindung betrifft eine Arbeitsmaschine mit wenigstens einem hydraulischen Aktor zur Betätigung eines Arbeitsgerätes und einer durch ein Antriebsaggregat der Arbeitsmaschine angetriebenen ersten Verdrängereinheit, die den hydraulischen Aktor aus einem Hydrauliktank mit Hydraulikmedium speist, wobei wenigstens eine durch das Antriebsaggregat angetriebene zweite Verdrängereinheit vorgesehen ist, die im Arbeitsbetrieb den hydraulischen Aktor und/oder weitere hydraulische Verbraucher aus einem Hydrauliktank mit Hydraulikmedium speist und die während eines Rekuperationsbetriebs durch das von dem wenigstens einen hydraulischen Aktor oder einem hydraulischen Verbraucher verdrängte Hydraulikvolumen antreibbar ist, um kinetische Energie an das Antriebsaggregat zurückzuspeisen.

Hydraulic drive system of construction machine

System for allocating fluid from multiple pumps to a plurality of hydraulic functions on a priority basis

A valve assembly (40) has a flow summation node (74) coupled to a displacement control (39) port of the first pump (50). Each valve (41-47) in the assembly has a variable metering orifice (75) controlling flow from an inlet (70) to a hydraulic actuator and has a variable source orifice (64) conveying fluid from a supply conduit (58) to a flow summation node. The source orifice enlarges as the metering orifice shrinks. Each valve includes a variable bypass orifice (80) and the bypass orifices of all the control valves are connected in series forming a bypass passage (85) between a bypass node (55) and a tank (53). The bypass node is coupled to the flow summation node and receives fluid from a second pump (51). At each valve, a source check valve (68) conveys fluid from the supply conduit to the inlet and a bypass supply check valve (89) conveys fluid from the bypass passage to the inlet.

System for allocating fluid from multiple pumps to a plurality of hydraulic functions on a priority basis

Hydraulic driving control device and hydraulic shovel with the control device

Hydraulic drive control device

Hydraulic system with open loop electrohydraulic pressure compensation

CONTROLLING OPERATION OF DIESEL-HYDRAULIC DRIVE

Controlling operation of a diesel-hydraulic device

An arrangement for operating a diesel-hydraulic drive on a construction machine in limit-load control with a microprocessor controller in which the installed hydraulic power is greater than the rated output of the diesel engine. Upon thermal and/or diesel-engine overload the hydraulic power which can be taken off is reducible; in the case of non-output loading, after a selectably predetermined time the diesel engine can be switched to idling speed of rotation and hydraulic displacement pumps can be operated with minimum delivery oil quantity; and the adjustable hydraulic displacement pumps can be adjusted in accordance with selectably predeterminable output curves.

Control unit for construction machine

Hydraulic drive apparatus of work machine

A hydraulic drive apparatus of a work machine capable of securely providing a fuel cost reduction effect also in an actual work in which working conditions vary every hour. The apparatus comprises a working condition discriminating part (41) discriminating working conditions and a hydraulic pump controller (40b) controlling the absorption torque of a hydraulic pump (18). When the working conditions discriminated by the working condition discriminating part (41) an specific ones, the hydraulic pump controller (40b) controls the absorption torque of the hydraulic pump (18) so that the absorption torque characteristic line of the hydraulic pump (18) matches the absorption torque characteristic line (PLb) of the hydraulic pump which makes equal the output torque of an engine (17) to the absorption torque of the hydraulic pump (18) at an engine output torque point (Mb) where a fuel consumption is approximately minimized.

Control system for hybrid construction machine

A controller determines whether or not the storage amount of a battery is below a threshold, and reduces an assist output of a sub-pump by controlling an assist control mechanism based on an assist correction coefficient, increases the discharge amount of a main pump by controlling an engine controller based on an engine rotation speed correction coefficient and increasing the rotation speed of an engine, and increases an output of the main pump by increasing the rotation speed of the engine by as much as a reduction in the assist output of the sub-pump.

Meterless hydraulic system having multi-actuator circuit

A hydraulic system is disclosed. The hydraulic system may have a pump, a first actuator, and a meterless circuit connecting the first actuator to the pump. The hydraulic system may also have a second actuator connected to the meterless circuit in parallel with the first actuator. The second actuator may be a variable-area linear actuator

Flow control system for a hydraulic pump of construction machinery

A flow control system of a hydraulic pump for a construction machine is provided, which can variably control a discharge flow rate of the hydraulic pump in accordance with load pressure generated by a hydraulic actuator such as a boom cylinder. According to the flow control system of a hydraulic pump, the discharge pressure of the hydraulic pump and the operation rate of the operation lever for the hydraulic actuators is detected, and standard load pressures of the respective hydraulic actuators are set. If the discharge pressure of the hydraulic pump is higher than the preset standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is proportionally reduced for the same operation rate in accordance with degrees of loads generated by the hydraulic actuators, while if the discharge pressure of the hydraulic pump is lower than the standard load pressures of the hydraulic actuators, the discharge flow rate of the hydraulic pump is controlled in proportion to the operation rate.

Torque output control for swing pump

A hydraulic circuit including a hydraulic swing motor having a first port and a second port. A first motor conduit connected to the first port of the hydraulic swing motor, and a second motor conduit connected to the second port of the hydraulic swing motor. The hydraulic circuit further includes a pump to selectively supply a flow of pressurized hydraulic fluid to the hydraulic swing motor through the first and the second motor conduits. A controller electrically connected to the pump adjusts a torque output of the pump based on a swing speed of the hydraulic swing motor.

Electronic load drop protection for hydraulic fluid system

A method of controlling a valve includes detecting a supply pressure at a fluid source and detecting a first port pressure at a first side of a piston. A controller actuates the valve from a closed position to a first open position when the supply pressure is in excess of the first port pressure. Thereafter, the controller actuates the valve to the closed position when the supply pressure is less than the first port pressure.

Working machine

A working machine rendered to change in setting a maximum value of an absorption torque of hydraulic pump to a rather high value when the working machine is in a specified state, solves problems that, when an operation lever is being operated in an intermediate position of a lever stroke, there occurs a swinging in a machine body due to change-over of a maximum absorption torque setting value so that the operation lever is relatively moved with respect to the machine body to exert an influence on operability and the machine body acting violently. When the maximum absorption torque setting value is E2 position which is good fuel efficiency, upon detection of a full operation of either one or both of the travelling operation member and the boom operation member, controlling to automatically switch to E1 position of a maximum absorption torque larger than that of E2 position is performed.

Hydraulic system for construction machine including emergency control unit for electric hydraulic pump

The present disclosure relates to a hydraulic system for a construction machine which uses an electric hydraulic pump, and more particularly, to a hydraulic system including an emergency control unit for temporarily driving the construction machine when an electronic control unit controlling the electric hydraulic pumps fails to operate. To this end, disclosed is the hydraulic system including the electric hydraulic pump, the electric control unit for controlling the electric hydraulic pump, and the emergency control unit, which operates when the electric control unit fails to operate, so as to temporarily control the electric hydraulic pump in accordance with to a predetermined condition, which can effectively respond to a low load work corresponding to predetermined pressure and to a high load work corresponding to higher pressure, by selectively operating the emergency control unit according to different optional conditions, based on the amount of load (low load, high load) of the working machine that is required when the electric control unit fails to operate.

Relief Pressure Control Device for Hydraulic Work Machine

A relief pressure control system is provided with a controller for outputting, responsive to an adjustment signal output from a dial switch, a control signal to control a relief pressure of a variable solenoid relief valve, a display unit for displaying, responsive to display signals outputted from the controller, a relationship between a circuit pressure output from a pressure sensor and a pressure required by a hydraulic cylinder, and a control device constituting a start instruction unit for instructing a start of control of the variable solenoid relief valve. Stop valves are arranged in sections of main lines, which communicate a directional control valve and the hydraulic cylinder with each other, to open or close the section. The sections are located between positions on the main lines, where the variable solenoid relief valves are connected to the main lines, respectively, and the hydraulic cylinder.

CONSTRUCTION MACHINE

A construction machine, comprising a hydraulic pump, a swing hydraulic motor, a swing electric motor, a delivery capacity regulating device, and a control unit which controls the driving/braking of the swing structure, is configured to comprise an operation amount detection device for detecting the operation amount of the swing control lever and a speed detection device for detecting the speed of the swing electric motor. The control unit includes a hydraulic pump output reduction control unit which takes in an operation amount signal representing the operation amount of the swing control lever detected by the operation amount detection device and a speed signal representing the speed of the swing electric motor detected by the speed detection device and controls the delivery capacity regulating device by calculating a reduction rate of the output of the hydraulic pump based on the detection signals. 1. A construction machine comprising: an engine; a hydraulic pump of the variable displacement type which is driven by the engine; a swing structure; a swing hydraulic motor which drives the swing structure by using hydraulic fluid delivered from the hydraulic pump; an electrical storage device which stores and supplies electric power; a swing electric motor which drives the swing structure by using the electric power supplied from the electrical storage device; a swing control lever which is operated for commanding the driving of the swing structure; a delivery capacity regulating device which regulates the delivery capacity of the hydraulic pump; and a control unit which controls the driving/braking of the swing structure by using the sum total of torque of the swing hydraulic motor and torque of the swing electric motor by driving both the swing hydraulic motor and the swing electric motor when the swing control lever is operated , wherein:the construction machine comprises an operation amount detection device which detects the operation amount of the swing control ...

VARIABLE LOAD SENSE OPEN CENTER HYBRID SYSTEM

A load sense open center hydraulic system provides efficiency and operator feedback and includes one or more constant flow-open center valves (); respective one or more parallel power cores () operatively coupled to the one or more constant flow-open center valves; a variable capacity pump () directly fluidly connected to the one or more parallel power cores; and a pressure compensated flow control fluidly connected between the variable capacity pump and the one or more constant flow-open center valves. The one or more constant flow-open center valves are not fluidly coupled to a fixed capacity pump. 1. An open center hydraulic system comprising:one or more constant-flow, open center valves;a parallel power core operatively coupled to the one or more constant-flow, open center valves;a variable capacity pump fluidly connected to and configured to provide pressurized fluid to the one or more constant-flow, open center valves, and directly fluidly connected to the parallel power core; anda flow restrictor fluidly connected between the variable capacity pump and the one or more constant-flow, open center valves.2. The hydraulic system of claim 1 , wherein the flow restrictor is a pressure compensated flow control fluidly connected between the variable capacity pump and the one or more constant-flow claim 1 , open center valves.3. The hydraulic system of any preceding claim claim 1 , wherein the one or more constant-flow claim 1 , open center valves include a plurality of serially connected constant-flow claim 1 , open center valves.4. The hydraulic system of any preceding claim claim 1 , wherein the one or more constant-flow claim 1 , open center valves are not fluidly coupled to a fixed capacity pump.5. The hydraulic system of any preceding claim claim 1 , wherein the pump is a load-sense pump.6. The hydraulic system of any preceding claim claim 1 , wherein the pump is set up as a remote pressure control pump.7. The hydraulic system of any preceding claim claim 1 , ...

Hydraulic system for construction machine, provided with protection device

A hydraulic system for a construction machine having a protection device is disclosed, which can limit a flow rate of hydraulic fluid that is discharged from a hydraulic pump in accordance with a hydraulic fluid temperature and notify an operator of information on the hydraulic fluid temperature. The hydraulic system for a construction machine includes a hydraulic actuator operated by hydraulic fluid that is supplied from a hydraulic pump; a control valve installed in a flow path between the hydraulic pump and the hydraulic actuator to control a flow rate of the hydraulic fluid that is supplied from the hydraulic pump to the hydraulic actuator; an oil cooler installed in a return flow path from the control valve to an hydraulic fluid tank to cool the hydraulic fluid; a hydraulic fluid temperature sensor detecting in real time a hydraulic fluid temperature of the hydraulic fluid tank; a hydraulic pump regulator controlling a discharge flow rate of the hydraulic pump through adjustment of an inclination angle of a swash plate of the hydraulic pump; and a controller comparing the hydraulic fluid temperature detected by the hydraulic fluid temperature sensor with a predetermined hydraulic fluid temperature, and outputting a control signal to the hydraulic pump regulator so as to limit the discharge flow rate of the hydraulic pump to or below a predetermined flow rate if the detected hydraulic fluid temperature is equal to or lower than a predetermined lower limit value, or equal to or higher than a predetermined upper limit value.

HYDRAULIC CONTROL SYSTEM

A hydraulic control system includes a flow rate control valve; a variable displacement hydraulic pump which is connected to the flow rate control valve and discharges hydraulic pressure to the flow rate control valve; a pump discharge pressure detector which is installed in a section where the flow rate control valve and the variable displacement hydraulic pump are connected, and detects the discharge pressure of the hydraulic pressure discharged from the variable displacement hydraulic pump to the flow rate control valve; and a hydraulic controller including a detection unit which is connected to the pump discharge pressure detector, detects the discharge pressure of the variable displacement hydraulic pump and converts the discharge pressure to a pump discharge pressure value, a comparison unit which receives the pump discharge pressure value from the detection unit, compares the pump discharge pressure value with a pre-stored lowest recognition pressure value, and determines whether the pump discharge pressure value is greater or less than the lowest recognition pressure value, and a calculation unit which, by interworking with the comparison unit, if the pump discharge pressure value is less than the lowest recognition pressure value, calculates a control pressure by recognizing the control 1. A hydraulic control system comprising:a flow control valve;a variable displacement hydraulic pump connected to the flow control valve to discharge pressurized fluid toward the flow control valve;a pump discharge pressure detector disposed on a passage between the flow control valve and the variable displacement hydraulic pump, the pump discharge pressure detector detecting a discharge pressure of the pressurized fluid discharged toward the flow control valve by the variable displacement hydraulic pump; and a detector connected to the pump discharge pressure detector to convert the detected discharge pressure to a pump discharge pressure value,', 'a comparator receiving the ...

Shovel, information processing device, information processing method, and non-transitory storage medium

A shovel includes a lower traveling body; an upper turning body pivotably attached to the lower traveling body; an attachment attached to the upper turning body; and a processor that stores in a memory, or transmits to an external device, log information including information on the shovel and information on a peripheral environment of the shovel upon detecting that a degree of stability on a motion of the shovel becomes less than a predetermined reference level, or upon detecting an indication that the degree of stability on the motion of the shovel becomes lower than the predetermined reference level.

Working vehicle

A wheel loader 1 comprises: an engine 3; a variable displacement HST pump 41; a variable displacement HST motor 42 connected to the HST pump 41 through a closed circuit; pressure sensors 72A, 72B configured to load pressure of the HST motor 42; and a controller 5, wherein the controller 5 is configured to, in a case of determining that a load pressure detection value P is included in a predetermined pressure range of greater than load pressure Pa corresponding to flat ground traveling and smaller than load pressure Pγ corresponding to an excavation operation, increase maximum rotational speed of the engine 3 only within the predetermined pressure range.

HYDRAULIC DRIVE SYSTEM OF CONSTRUCTION MACHINE

A hydraulic drive system of construction machine including: turning motor; turning operation device that outputs turning operation signal corresponding to inclination angle of operating lever; turning direction switching valve including spool and driver, driver receiving command current and driving spool, turning direction switching valve increasing amount of hydraulic liquid supplied to turning motor and amount of hydraulic liquid discharged from turning motor with increase in command current; controller that feeds command current to turning direction switching valve, wherein command current increases in accordance with increase in turning operation signal; and pressure sensor that detects outflow pressure of turning motor. Where turning operation signal decreases, when outflow pressure of turning motor, which is detected by pressure sensor, is higher than threshold and is increasing, controller feeds command current to turning direction switching valve, wherein a moving speed of spool is kept to be less than or equal to limiting value. 1. A hydraulic drive system of a construction machine , comprising:a turning motor;a turning operation device including an operating lever, the turning operation device outputting a turning operation signal corresponding to an inclination angle of the operating lever;a turning direction switching valve including a spool and a driver, the driver receiving a command current and driving the spool, the turning direction switching valve increasing an amount of a hydraulic liquid supplied to the turning motor and an amount of the hydraulic liquid discharged from the turning motor in accordance with increase in the command current;a controller that feeds the command current to the turning direction switching valve, such that the command current increases in accordance with increase in the turning operation signal; anda pressure sensor that detects an outflow pressure of the turning motor, whereinin a case where the turning operation signal ...

Work machine

To provide a work machine that makes it possible to drive actuators faster and more accurately by supplying flows to the actuators accurately at target rates without depending on load variations in a case where the machine body is controlled automatically by command inputs of a controller, while high operability is ensured for manual operation by an operator. In a case where a machine control function is cancelled via a machine control switch, a controller cancels limitation of the flow rate of a hydraulic fluid supplied to a plurality of directional control valves, the limitation being performed by the auxiliary flow rate control devices, and in a case where the machine control function is selected via the machine control switch, the controller causes the auxiliary flow rate control devices to limit the flow rate of the hydraulic fluid supplied to the plurality of directional control valves.

EXCAVATOR AND WORK SYSTEM

A shovel including a lower-part traveling body, an upper-part swiveling body which is enabled to swivel and is mounted to the lower-part traveling body, an actuator, and a control device that implements a first control process that causes the actuator to act autonomously, and a second control process that causes the actuator to act autonomously, wherein the control device is configured to select one control unit from among a plurality of control units that implements the first control process and the second control process, as a priority control process that is given priority to act, in a case where a conflict is judged to occur among the plurality of control units that implements the first control process and the second control process. 1. A shovel comprising:a lower-part traveling body;an upper-part swiveling body which is enabled to swivel and is mounted to the lower-part traveling body;an actuator; anda control device that implements a first control process that causes the actuator to act autonomously, and a second control process that causes the actuator to act autonomously,wherein the control device is configured to select one control unit from among a plurality of control units that implements the first control process and the second control process, as a priority control process that is given priority to act, in a case where a conflict is judged to occur among the plurality of control units that implements the first control process and the second control process.2. The shovel according to claim 1 ,wherein the control device is configured to select the one control unit from among the plurality of control units that implements the first control process and the second control process, as the priority control unit, based on a priority order preset for each of the plurality of control units in the case where the conflict is judged to occur between the first control process and the second control process.3. The shovel according to claim 1 ,wherein the control ...

Hydraulic Driving Apparatus

A counter balance valve (L) is located between a directional control valve () and a hydraulic motor (L) and provided on the way of a pair of supply/discharge lines (A, B). The counter balance valve (L) allows a spool (L) to be displaced axially based on a pressure difference between the supply/discharge lines (A, B). The counter balance valve (L) includes a communicating passage (L) for communicating the supply/discharge lines (A, B) when the displacement of the spool (L) exceeds a predetermined amount (X), based on a pressure difference between the supply/discharge lines (A, B). The communicating passage (L) is provided in the spool (L) of the counter balance valve (L). 1. A hydraulic driving apparatus comprising:a first hydraulic pump and a second hydraulic pump;a first hydraulic motor rotatively driven by pressurized oil from the first hydraulic pump;a second hydraulic motor rotatively driven by pressurized oil from the second hydraulic pump;a pair of first and second supply/discharge passages connecting the first hydraulic pump, a hydraulic oil tank and the first hydraulic motor;a pair of third and fourth supply/discharge passages connecting the second hydraulic pump, the hydraulic oil tank and the second hydraulic motor;a first directional control valve provided on the way of the first and second supply/discharge passages and switching the direction of the pressurized oil supplied and discharged between the first hydraulic pump, the hydraulic oil tank and the first hydraulic motor;a second directional control valve provided on the way of the third and fourth supply/discharge passages and switching the direction of the pressurized oil supplied and discharged between the second hydraulic pump, the hydraulic oil tank and the second hydraulic motor;a first counter balance valve located between the first directional control valve and the first hydraulic motor, provided on the way of the first and second supply/discharge passages and allowing a first spool to be ...

WORK MACHINE

A load sensing valve maintains a differential pressure at a set pressure by controlling a regulator in accordance with a differential pressure between a discharge pressure of a hydraulic pump and a load pressure of hydraulic actuators. A set pressure control device controls the set pressure. A controller controls the set pressure control device to reduce the set pressure more than when the work implement is being operated, when a predetermined determination condition that includes the work implement not being operated is satisfied. 1. A work machine comprising:a variable displacement hydraulic pump;a plurality of hydraulic actuators including a work implement actuator and a hydraulic motor, the plurality of hydraulic actuators being driven by hydraulic fluid discharged from the hydraulic pump;a work implement connected to the work implement actuator;a fan connected to the hydraulic motor;a control valve configured to control a flow rate of the hydraulic fluid supplied from the hydraulic pump to the plurality of hydraulic actuators;a regulator configured to control a discharge displacement of the hydraulic pump;a load sensing valve configured to control the regulator in accordance with a differential pressure between a discharge pressure of the hydraulic pump and a load pressure of the plurality of hydraulic actuators to maintain the differential pressure at a set pressure;a set pressure control device configured to control the set pressure; anda controller configured to control the set pressure control device so that the set pressure is reduced more when a determination condition including the work implement not being operated is satisfied than when the work implement is being operated.2. The work machine according to claim 1 , wherein control the set pressure control device so that the set pressure is set to a first pressure when the work implement is being operated, and', 'control the set pressure control device so that the set pressure is set to a second pressure ...

PRESSURE LOSS REDUCING CIRCUIT FOR A WORKS MACHINE

A pressure loss reducing circuit reduces a pressure loss of oil returning from an actuator to a direction switching valve with a simple configuration while suppressing an increase in the manufacturing cost and substantially eliminating the need of an additional installation space. The pressure loss reducing circuit includes a bypass valve disposed between an actuator oil path and a tank oil path of a direction switching valve, and opened and closed according to a signal from a controller, and moreover screwed into and attached to the direction switching valve. According to an operation signal of a switching spool when oil returning from an actuator is caused to flow to the actuator oil path, the controller opens the bypass valve so that the actuator oil path and the tank oil path communicate with each other and supplies the returning oil to the switching spool and the bypass valve to reduce a pressure loss.

Hydraulic Work Machine

A hydraulic work machine is provided in which left and right hydraulic motors are driven independently of each other by two hydraulic pumps and in which an anomaly of any of the left and right track devices can be detected with high accuracy. The hydraulic work machine includes a first pressure sensor configured to detect a first pump pressure that is a delivery pressure of a first hydraulic pump and a second pressure sensor configured to detect a second pump pressure that is a delivery pressure of a second hydraulic pump When a controller decides, from detection results of a travel operation detector and work operation detectors and that a work implement is not operated but travel operation devices and are operated and besides left and right track devices and are straightly traveling, the controller calculates an anomaly decision evaluation value based on a pressure difference value obtained by subtracting one from the other of the first pump pressure and the second pump pressure and decides, based on a result of comparison between the anomaly decision evaluation value and a predetermined decision reference value that one of the left and right track devices has an anomaly. 1. A hydraulic work machine , comprising:a first hydraulic pump and a second hydraulic pump of variable displacement type;a left track device including a left track hydraulic motor driven by hydraulic fluid supplied from the first hydraulic pump;a right track device including a right track hydraulic motor driven by hydraulic fluid supplied from the second hydraulic pump;a hydraulic actuator driven by hydraulic fluid supplied from at least one of the first hydraulic pump and the second hydraulic pump;a work implement driven by the hydraulic actuator;a travel operation device for operating the left track device and the right track device;a work operation device for operating the work implement;a controller that controls pump displacements of the first hydraulic pump and the second hydraulic pump in ...

Method for controlling flow rate of hydraulic pump of construction machine

A method is provided for controlling the flow rate of a hydraulic pump of a construction machine, including: a step of detecting the operation amount of a rotation operation lever, and the rotation pressure generated in a swing motor; a step of calculating the flow rate required for rotating, the flow rate corresponding to the operation amount of the rotation operation lever; a step of calculating a rotation acceleration first inclination value for increasing the discharge flow rate of the hydraulic pump to a certain inclination value from a rotation initiation time when the upper rotating body rotates; a step of calculating a second inclination value compensating for the first inclination value by a difference value between the detected rotation pressure value of the swing motor and the reference pressure corresponding to the set pressure of the relief valve of the swing motor; and to step of restricting the discharge flow rate of the hydraulic pump such that the increased amount of the flow rate required for rotating is restricted to the flow rate of the second inclination value.

Construction Machine

To make it possible to prevent a decrease in work speed due to a decrease in the speed of a given actuator when an operator unintentionally performs a fine operation of the control lever of the other actuator in a state in which the given actuator is driven by the hydraulic fluid delivered from a plurality of pumps, a controller ( 41 ) sets, as a composite dead zone line serving as a boundary of a composite dead zone, a composite dead zone line such that as an operation amount in one direction of a control lever ( 12 L) or ( 13 L) of a control lever device ( 12 ) or ( 13 ) is increased, the width of the composite dead zone corresponding to an operation amount in the other direction of the control lever is widened, and corrects the operation amount in the other direction such that the demanded flow rate of an actuator increases from zero, when the control lever is operated in the other direction in a state in which the operation amount in the one direction of the control lever remains within a range of the composite dead zone, and the operation amount in the other direction exceeds the composite dead zone line.

Hydraulic Pressurizing Medium Supply Assembly for a Mobile Work Machine, and Method

A hydraulic pressurizing medium supply assembly has an adjustable axial piston machine. An actuating cylinder is controlled by way of a pilot valve. The pilot valve is actuated by a control installation. The control installation, as input variables, has an actual pressure and/or an actual swivel angle of the adjustable axial piston machine. One or a plurality of the input variables are compared with a matching nominal value and a control value is emitted, or in each case a control value is emitted. The controlling of the input variables is part of a first closed-loop control circuit. An underlying second closed-loop control circuit has an input variable which is based on the control variable or the control variables and serves as a nominal variable. A further input variable of the second closed-loop control circuit is an actual delivery-volume adjustment rate of the axial piston machine. 1. A hydraulic pressurizing medium supply assembly for an open hydraulic circuit , comprising:a hydro machine;an adjusting mechanism including (i) an actuating cylinder having a set piston configured to adjust a delivery volume of the hydro machine, and (ii) a pilot valve electrically actuatable in a proportional manner, wherein an inflow to and/or an outflow from a control chamber of the actuating cylinder that is limited by the set piston is configured for control via the pilot valve in order for an actuation of the set piston to be impinged with pressurizing medium; andan electronic control which, as input variables, has at least a nominal outlet pressure of the hydro machine and/or a nominal delivery volume or a nominal swivel angle of the hydro machine, and which, as an output variable, has a control variable for the pilot valve,wherein the electronic control has a first closed-loop control circuit for an actual outlet pressure of the hydro machine and/or for an actual delivery volume or an actual swivel angle of the hydro machine,wherein the electronic control, so as to ...

Drive for a machine

A drive for a machine includes a computer configured to control a first electric motor for driving vehicle wheels and a second electric motor for driving a work attachment. The second electric motor is configured to drive at least one hydraulic pump with an adjustable stroke volume. A sensor is configured to detect the stroke volume of the pump. The computer processes the stroke volume to control the second electric motor.

WORKING MACHINE

A working machine includes a controller configured or programmed to perform an automatic deceleration for automatically decelerating a left traveling motor and a right traveling motor rotated at a second speed by shifting from the second speed to the first speed, and to determine a deceleration threshold that is used for judging whether the automatic deceleration has to be performed or not. 1. A working machine comprising:a machine body;a prime mover provided on the machine body;a left traveling device provided on a left portion of the machine body;a right traveling device provided on a right portion of the machine body;a left traveling motor configured to output power to the left traveling device and to be rotated at a speed shiftable between a first speed and a second speed higher than the first speed;a right traveling motor configured to output power to the right traveling device and to be rotated at a speed shiftable between the first speed and the second speed higher than the first speed; anda controller configured or programmed to perform an automatic deceleration for automatically decelerating the left traveling motor and the right traveling motor rotated at the second speed by shifting from the second speed to the first speed, and to determine a deceleration threshold that is used for judging whether the automatic deceleration has to be performed or not.2. The working machine according to claim 1 , further comprisinga traveling operation member operable to change rotational directions of the left traveling motor and the right traveling motor, whereinthe controller is configured or programmed to change the deceleration threshold according to an operation of the traveling operation member.3. The working machine according to claim 2 , whereinthe controller is configured or programmed to acquire either a turn correction coefficient or a straight-traveling correction coefficient, the turn correction coefficient being provided for determining a deceleration ...

WORKING MACHINE

A working machine includes a controller to perform automatic deceleration to automatically reduce a first rotation speed of a left traveling motor to output a power to a left traveling device on a left portion of a machine body and a second rotation speed of a right traveling motor to output a power to a right traveling device on a right portion of the machine body by shifting a speed stage of each of the left and right traveling motors from a second speed to a first speed that is lower than the second speed. The controller is configured or programmed to determine, based on the second rotation speed, a left threshold for judging whether to perform the automatic deceleration in left pivot turn of the machine body, and to determine, based on the first rotation speed, a right threshold for judging whether to perform the automatic deceleration in right pivot turn of the machine body. 1. A working machine comprising:a machine body;a left traveling device located left on the machine body;a right traveling device located right on the machine body;a left traveling motor to output a power to the left traveling device;a right traveling motor to output a power to the right traveling device;a first rotation detector to detect a first rotation speed that is a rotation speed of the left traveling motor;a second rotation detector to detect a second rotation speed that is a rotation speed of the right traveling motor;a left traveling pump to supply operation fluid to the left traveling motor;a right traveling pump to supply operation fluid to the right traveling motor;a traveling operation device to operate at least one of the left traveling pump and the right traveling pump; anda controller configured or programmed to perform automatic deceleration to automatically reduce the first rotation speed and the second rotation speed by shifting a speed stage of each of the left and right traveling motors from a second speed stage to a first speed stage that is lower than the second speed ...

Working machine

A working machine includes a controller configured to determine a first deceleration threshold corresponding to each of a first traveling pressure, a second traveling pressure, a third traveling pressure, and a fourth traveling pressure, to perform automatic deceleration to reduce rotation speeds of a left traveling motor and a right traveling motor, and to judge whether to perform the automatic deceleration based on the determined first deceleration threshold, the first traveling pressure, the second traveling pressure, the third traveling pressure, and the fourth traveling pressure.

WORKING MACHINE

A working machine includes a first pressure detector configured to detect a first pilot pressure that is a pressure of operation fluid passed through a first traveling fluid line, a second pressure detector configured to detect a second pilot pressure that is a pressure of operation fluid passed through a second traveling fluid line, a third pressure detector configured to detect a third pilot pressure that is a pressure of operation fluid passed through a third traveling fluid line, a fourth pressure detector configured to detect a fourth pilot pressure that is a pressure of operation fluid passed through a fourth traveling fluid line, and a controller configured or programed to judge in which of the left-front, right-front, left-rear and right-rear operation areas an operational position of the traveling operation member exists. 1. A working machine comprising:a machine body;a left traveling device provided on a left portion of the machine body;a right traveling device provided on a right portion of the machine body;a left traveling motor configured to output power to the left traveling device;a right traveling motor configured to output power to the right traveling device;a left traveling pump to supply operation fluid to the left traveling motor, the left traveling pump including a first pressure receiving portion and a second pressure receiving portion so that the operation fluid is used to apply a pressure to at least one of the first and second pressure receiving portions;a right traveling pump to supply operation fluid to the right traveling motor, the right traveling pump including a third pressure receiving portion and a fourth pressure receiving portion so that the operation fluid is used to apply a pressure to at least one of the third and fourth pressure receiving portions;{'claim-text': 'a traveling operation member operably movable from a neutral position to any one of a left-front operation area, a right-front operation area, a left-rear operation ...

APPARATUS WITH HYDRAULIC MACHINE CONTROLLER

A prime mover and a plurality of hydraulic actuators, a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising a plurality of working chambers, a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators, each working chamber of the hydraulic machine comprising a low-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a low-pressure manifold and a high-pressure valve which regulates the flow of hydraulic fluid between the working chamber and a high-pressure manifold. The hydraulic machine being configured to actively control at least the low-pressure valves of the group of one or more working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the group of one or more working chambers, responsive to a demand signal, wherein the apparatus further comprises a controller configured to calculate the demand signal in response to a measured property of the hydraulic circuit or one or more actuators. 1. An apparatus comprising a prime mover and a plurality of hydraulic actuators , a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising a plurality of working chambers having a volume which varies cyclically with rotation of the rotatable shaft , a hydraulic circuit extending between a group of one or more working chambers of the hydraulic machine and one or more of the hydraulic actuators ,each working chamber of the hydraulic machine comprising a low-pressure valve configured to regulate a flow of hydraulic fluid between the working chamber and a low-pressure manifold and a high-pressure valve configured to regulate the flow of hydraulic fluid between the working chamber and a high-pressure manifold,the hydraulic machine being ...

WORKING MACHINE

A working machine includes a fan motor driven with hydraulic fluid, the fan motor including a first port and a second port, a bypass fluid passage connecting the first port of the fan motor and the second port to each other, a flow rate control valve provided on the bypass fluid passage to control a flow rate of the hydraulic fluid flowing in the bypass fluid passage, a drain passage configured to drain the hydraulic fluid upstream of the flow rate control valve, and an unloading valve shiftable between a full-closing position to close the drain passage and a full-opening position to open the drain passage. 1. A working machine comprising:a fan motor driven with hydraulic fluid, the fan motor including a first port and a second port;a bypass fluid passage fluidly connecting the first port or vicinity thereof and the second port or vicinity thereof to each other to bypass the fan motor;a flow rate control valve provided on the bypass fluid passage to control a flow rate of the hydraulic fluid flowing in the bypass fluid passage;a drain passage configured to drain the hydraulic fluid upstream of the flow rate control valve; andan unloading valve shiftable between a full-closing position to close the drain passage and a full-opening position to open the drain passage.2. The working machine according to claim 1 , whereinthe drain passage is fluidly connected to the bypass fluid passage.3. The working machine according to claim 1 , whereinthe unloading valve is shifted from the full-opening position to the full-closing position when the flow rate control valve is open at a predetermined opening degree.4. The working machine according to claim 3 , whereinthe flow rate control valve is closed after a predetermined period elapses since the shifted unloading valve reaches the full-closing position.5. The working machine according to claim 1 , whereinthe unloading valve is shifted from the full-opening position to the full-closing position while the flow rate control valve ...

WORKING MACHINE

A working machine includes a prime mover, a traveling pump configured to deliver hydraulic fluid at a flow rate corresponding to an angle of the swashplate, a traveling motor configured to be rotated by the hydraulic fluid delivered from the traveling pump so as to have a rotation speed shiftable between a first speed and a second speed higher than the first speed, a traveling change-over valve shiftable between a first state to set the rotation speed of the traveling motor to the first speed and a second state to set the rotation speed of the traveling motor to the second speed, an operation device, an operation valve configured to change the angle of the swashplate of the traveling pump according to operation of the operation device, an actuation valve provided upstream or downstream of the operation valve and fluidly connected to the operation valve, and a controller configured or programmed to output a control signal to control the actuation valve in such a way that, when the traveling change-over valve is shifted from the second state to the first state, a value of the control signal is reduced from a set value to a mitigation value less than the set value and then restores to the set value. The controller is configured or programmed to reduce the value of the control signal from the set value to the mitigation value for a mitigation period in such a way that a first reduction rate that is a rate of reducing the value of the control signal for a first part of the mitigation period between a start point thereof and an intermediate point thereof larger than a second reduction rate that is a rate of reducing the value of the control signal for a second part of the mitigation period between the intermediate point thereof and an end point thereof. 1. A working machine comprising:a traveling pump including a swashplate and configured to deliver hydraulic fluid and change a flow rate of the hydraulic fluid delivered therefrom in correspondence to an angle of the ...

Working machiine

A working machine includes a first rotation detector to detect a first rotation speed of the left traveling motor, a second rotation detector to detect a second rotation speed of the right traveling motor, and a controller to perform automatic deceleration to automatically reduce the first rotation speed and the second rotation speed both set at respective second speed stages by shifting a speed stage of each of the first rotation speed and the second rotation speed to a first speed stage that is lower than the second speed stage. During straight traveling of a machine body of the working machine, the controller determines a straight-traveling threshold serving as a deceleration threshold for judging whether to perform the automatic deceleration based on the first rotation speed or the second rotation speed.

SYSTEM INCLUDING WORK MACHINE, COMPUTER IMPLEMENTED METHOD, METHOD FOR PRODUCING TRAINED POSITION ESTIMATION MODEL, AND TRAINING DATA

There is provided a system including a work machine, comprising a main body of the work machine, a work implement attached to the main body of the work machine, an operating member operated to operate the work implement, and a computer. The computer has a trained position estimation model for determining the position of a portion of the work implement that is a target of positional estimation. The computer obtains an operation command value causing the work implement to make a movement in response to an operation of the operating member, uses the trained position estimation model to estimate from the operation command value an amount of displacement of the target of positional estimation from a reference position, and outputs an estimated position that is a position of the target of positional estimation estimated from the reference position and the amount of displacement. 1. A system including a work machine , comprising:a main body of the work machine;a work implement attached to the main body of the work machine;an operating member operated to operate the work implement; anda computer, whereinthe computer has a trained position estimation model to determine a position of a target of positional estimation that is a portion of the work implement to be subject to positional estimation, andthe computer obtains an operation command value causing the work implement to make a movement in response to an operation of the operating member, uses the trained position estimation model to estimate from the operation command value an amount of displacement of the target of positional estimation from a reference position, and outputs a first estimated position that is a position of the target of positional estimation estimated from the reference position and the amount of displacement.2. The system according to claim 1 , wherein the trained position estimation model undergoes a learning process using a training data set so that when the operation command value is received claim ...

HYDRAULIC CONTROL SYSTEM, WORK MACHINE AND METHOD FOR CONTROLLING OPERATION OF A WORK ATTACHMENT

The invention refers to a hydraulic control system for controlling operation of a work attachment of a work machine, comprising a controller configured to output a work attachment control value controlling the operation of the work attachment, an operator input device configured to output a command signal depending on the amount of actuation of the operator input device for setting the work attachment control value, a save input device configured to generate a save command signal upon actuating the save input device and a mode select input device configured to select a first mode and a second mode, wherein the controller is configured to save a constant work attachment control value, wherein the constant work attachment control value is the work attachment control value as set by the command signal upon receiving the save command signal. 1: A hydraulic control system for controlling operation of a work attachment of a work machine , comprisinga controller configured to output a work attachment control value controlling the operation of the work attachment,an operator input device operatively connected to the controller, wherein the operator input device is configured to output a command signal depending on the amount of actuation of the operator input device for setting the work attachment control value,a save input device operatively connected to the controller, wherein the save input device is configured to generate a save command signal upon actuating the save input device,wherein the controller is configured to save a constant work attachment control value, wherein the constant work attachment control value is the work attachment control value as set by the command signal upon receiving the save command signal.2: The hydraulic control system according to characterized by a mode select input device operatively connected to the controller and configured to select a first mode and a second mode claim 1 , whereinin the first mode, the controller outputs the work ...

SYSTEM AND METHOD FOR MAXIMIZING PRODUCTIVITY OF A WORK VEHICLE

A system for maximizing productivity of a work vehicle is disclosed. The system includes a first sensor system that generates a first signal output indicative of a height of a material arranged forward of the work vehicle. A second sensor system generates a second signal output indicative of a position and height of a material transport blade coupled to the work vehicle. An actuator system configured to adjust the position and height of the material transport blade. An electronic data processor is communicatively coupled to each of the first sensor system, the second sensor system, and the actuator system. The electronic data processor determines a material flow rate based on the first and second signal outputs, and generates a command signal received by the actuator system to dynamically adjust a plurality of operating parameters associated with the material transport blade to maximize the material flow rate. 1. A system for maximizing productivity of a work vehicle , the system comprising:a first sensor system, wherein the first sensor system is configured to generate a first signal output indicative of a height of a material arranged forward of the work vehicle relative to a reference point on the work vehicle;a second sensor system, wherein the second sensor system is configured to generate a second signal output indicative of a blade position and blade height of at least one material transport blade coupled to the work vehicle;an actuator system coupled to the work vehicle and the at least one material transport blade, wherein the actuator system configured to adjust the blade position and the blade height of the at least one material transport blade; andan electronic data processor communicatively coupled to each of the first sensor system, the second sensor system, and the actuator system, wherein the electronic data processor is configured to determine a material flow rate of the material based on the first signal output and the second signal output, and ...

ELECTROHYDRAULIC CONTROL DEVICE FOR CONSTRUCTION MACHINE AND METHOD THEREOF

An electro-hydraulic control apparatus for construction machinery includes a control valve installed in a hydraulic line between a hydraulic pump and an actuator to control operations of the actuator according to a displacement amount of a spool therein, a spool displacement adjusting valve configured to output a secondary pressure in proportion to an inputted pressure command signal to the spool of the control valve to control the displacement amount of the spool of the control valve, a pressure sensor to detect the secondary pressure outputted from the spool displacement adjusting valve, and a controller configured to output the pressure command signal to the spool displacement adjusting valve according to a manipulation signal of the construction machinery, and to correct the pressure command signal when a pressure difference between the detected secondary pressure and a design pressure predetermined by the pressure command signal is out of a preset allowable range. 1. An electro-hydraulic control apparatus for construction machinery , comprising:a control valve installed in a hydraulic line between a hydraulic pump and an actuator to control operations of the actuator according to a displacement amount of a spool therein;a spool displacement adjusting valve configured to output a secondary pressure in proportion to an inputted pressure command signal to the spool of the control valve to control the displacement amount of the spool of the control valve;a pressure sensor to detect the secondary pressure outputted from the spool displacement adjusting valve; anda controller configured to output the pressure command signal to the spool displacement adjusting valve according to a manipulation signal of the construction machinery, and to correct the pressure command signal when a pressure difference between the detected secondary pressure and a design pressure predetermined by the pressure command signal is out of a preset allowable range.2. The electro-hydraulic ...

HYDRAULIC DRIVE SYSTEM FOR CONSTRUCTION MACHINE

An object to achieve favorable operability, in a combined operation that involves a specific actuator and involves a great difference in load pressure and when an operation of an operating unit for the specific actuator is a fine operation, by reducing energy consumption arising from wasted restricting pressure loss of a pressure compensating valve and by flexibly varying a flow rate of a hydraulic fluid supplied to the specific actuator depending on the load pressure. To achieve this object, a boom cylinder () is provided with an open center type flow control valve () that controls a hydraulic fluid from a main pump () and a closed center type flow control valve () that controls a hydraulic fluid from a main pump (). The main pump () is subject to load sensing control. The flow control valve () is opened to control a supply flow rate up to an intermediate zone of an operating range of an operating unit for the boom cylinder (). Both the flow control valves () and () are opened to control the supply flow rate after the intermediate zone. 1. A hydraulic drive system for a construction machine , comprising:a variable displacement first pump device;a second pump device;a plurality of first actuators that are driven by hydraulic fluids delivered from the first pump device;a plurality of second actuators that are driven by hydraulic fluids delivered from the second pump device;a plurality of closed center type flow control valves that control flows of hydraulic fluids supplied from the first pump device to the first actuators;a plurality of open center type flow control valves that control flows of hydraulic fluids supplied from the second pump device to the second actuators;a plurality of pressure compensating valves that control differential pressures across the respective closed center type flow control valves; anda first pump control unit including a load sensing control section that controls capacity of the first pump device such that a delivery pressure of the ...

DEVICE FOR CONTROLLING ENGINE AND HYDRAULIC PUMP OF CONSTRUCTION EQUIPMENT AND CONTROL METHOD THEREFOR

Disclosed are: a device for controlling an engine and a hydraulic pump of construction equipment, capable of increasing fuel efficiency by controlling an engine speed and a hydraulic pump discharge flow rate according to the load of a work device; and a control method therefor. The device for controlling the engine and a hydraulic pump of construction equipment, according to the present invention, comprises: a fuel efficiency selection mode means; an engine RPM control means; a hydraulic pump control means; a work device operation sensing means; and a controller having a first control mode such that in the case of selecting the fuel saving mode, the engine RPM is outputted at the RPM lower than that of the general mode while a swash plate swivel angle of the hydraulic pump is increased corresponding to the operation amount of the operation lever, and in the case of the swash plate swivel angle of the hydraulic pump reaching the maximum angle, the engine RPM is increased so as to discharge the flow rate corresponding to the operation amount of the operation lever. 1. A device for controlling an engine and a hydraulic pump of construction equipment comprising;a fuel efficiency selection mode means for selecting either a fuel saving mode or a general mode,an engine RPM control means for controlling the engine RPM,a hydraulic pump control means for controlling the displacement rate of the hydraulic pump by controlling a swash plate swivel angle of the hydraulic pump,a work device operation sensing means for sensing an operation amount of an operation lever in order to operate a work device, anda controller having a first control mode wherein, in the case of selecting the fuel saving mode, the engine RPM is outputted at a RPM lower than that of the general mode while the swash plate swivel angle of the hydraulic pump is increased corresponding to the operation amount of the operation lever, and in the case of the swash plate swivel angle of the hydraulic pump reaching ...

Work Machine

It is made possible to suppress variations of the speed of an actuator into which a regeneration flow rate flows, regardless of variations of the regeneration flow rate caused by posture changes of the front part and to enhance the operability when the front part moves in the free fall direction, and hydraulic fluid discharged from an actuator driving the front part is regenerated. Accordingly, a controller of a hydraulic system is provided with a regeneration control calculation section and a pump flow rate control calculation section 19and when the regeneration control calculation section controls a regeneration valve to perform regeneration, the pump flow rate control calculation section controls a pump flow rate regulation device to increase the delivery flow rate of a hydraulic pump as the angle of an arm approaches the vertically downward direction based on posture information about the arm acquired by an inertial measurement unit 1. A work machine comprising:a front work implement constituted by a plurality of front parts, each of the plurality of front parts being pivotably connected with a machine body or other front parts; anda hydraulic system including a plurality of actuators that drive the plurality of front parts,the plurality of front parts including a first front part that can move in a free fall direction,the plurality of actuators including a first actuator that is a hydraulic cylinder type that drives the first front part, a regenerating circuit that supplies a hydraulic fluid discharged from a hydraulic fluid discharge-side of the first actuator to a hydraulic fluid supply-side of a second actuator;', 'a regeneration control device that controls a regenerating state of the regenerating circuit;', 'a hydraulic pump that supplies hydraulic fluid to the second actuator; and', 'a pump flow rate regulation device that controls a delivery flow rate of the hydraulic pump, wherein the work machine further comprises:', 'a posture information acquiring ...

WORK MACHINE AND METHOD FOR CONTROLLING THE SAME

A work machine includes: a boom; a dipper stick attached to a distal end of the boom; a bucket attached to a distal end of the dipper stick; and a loading determination unit configured to determine that an operation of the work machine is a loading operation for loading an excavated matter into a loading target under a condition that the bucket moves across a reference level. 1. A work machine comprising:a boom;a dipper stick attached to a distal end of the boom;a bucket attached to a distal end of the dipper stick; anda loading determination unit configured to determine that an operation of the work machine is a loading operation for loading an excavated matter into a loading target under a condition that the bucket moves across a reference level.2. The work machine according to claim 1 , further comprising an input device claim 1 , wherein the loading determination unit receives an input from an operator via the input device for setting the reference level.3. The work machine according to claim 1 , further comprising:a first cylinder to drive the boom;a second cylinder to drive the dipper stick;a third cylinder to drive the bucket;a first sensor to sense a stroke length of the first cylinder;a second sensor to sense a stroke length of the second cylinder;a third sensor to sense a stroke length of the third cylinder; anda level calculation unit configured to calculate a level of the bucket based on the stroke length of the first cylinder as sensed, the stroke length of the second cylinder as sensed, and the stroke length of the third cylinder as sensed,wherein the loading determination unit determines, based on the level of the bucket as calculated, whether the bucket moves across the reference level.4. The work machine according to claim 1 , wherein the loading determination unit determines that an operation of the work machine is the loading operation under a condition that the bucket moves across the reference level and the bucket also assumes a position to hold ...

SYSTEM FOR CONTROLLING CONSTRUCTION MACHINE AND METHOD FOR CONTROLLING CONSTRUCTION MACHINE

A control system for construction machinery, includes a hydraulic pump, at least one control valve installed in a center bypass line connected to the hydraulic pump and configured to control a flow direction of a working oil discharged from the hydraulic pump to selectively supply the working oil to an actuator, a bypass control valve installed downstream from the control valve in the center bypass line to variably control an amount of the working oil draining to a drain tank through the center bypass line, and a controller configured to control operations of the hydraulic pump and the bypass control valve according to a manipulation signal of an operator and to open the bypass control valve according to pump peak occurrence to reduce a pump peak. 1. A control system for construction machinery , comprising:a hydraulic pump;at least one control valve installed in a center bypass line connected to the hydraulic pump, and configured to control a flow direction of a working oil discharged from the hydraulic pump to selectively supply the working oil to an actuator;a bypass control valve installed downstream from the control valve in the center bypass line to variably control an amount of the working oil draining to a drain tank through the center bypass line; anda controller configured to control operations of the hydraulic pomp and the bypass control valve according to a manipulation signal of an operator, and to open the bypass control valve according to pump peak occurrence to reduce a pump peak.2. The control system for construction machinery of claim 1 , wherein the controller comprisesa sudden stop determiner determining whether or not a sudden stop manipulation of the actuator occurs, based on a joystick manipulation signal;a calculator determining an opening area of the bypass control valve in case of the sudden stop manipulation of the actuator; andan output portion outputting a control signal for opening the bypass control valve according to the calculated ...

WORKING MACHINE

A working machine includes a traveling motor having a first speed and a second speed, an operation detector device to detect an operation extent of a traveling operation member, a controller device having an automatic decelerator portion to perform an automatic deceleration for reducing a revolving speeds of the traveling motor, and a storage device storing first control information representing a relation between a first-speed regulating revolving speed corresponding to the operation extent at the first speed and a second-speed regulating revolving speed corresponding to the operation extent at the second speed. The automatic decelerator portion obtains the first-speed regulating revolving speed based on the first control information and the operation extent when the traveling motor is at the second speed, and performs the automatic deceleration when the motor revolving speed is equal to or less than the first-speed regulating revolving speed. 1. A working machine comprising:a machine body;a pair of traveling devices, one of the traveling devices being arranged to a left side of the machine body, the other one of the traveling devices being arranged to a right side of the machine body;a traveling operation member;a pair of traveling motors each having a first speed and a second speed higher than the first speed, one of the traveling motors being configured to provide power to the traveling device arranged to the left side, the other one of the traveling motors being configured to provide power to the traveling device arranged to the right side;a pair of traveling pumps to be driven by operation of the traveling operation member, one of the traveling pumps being configured to supply operation fluid to the one of the traveling motors, the other one of the traveling pumps being configured to supply operation fluid to the other one of the traveling motors;a revolving speed detector device to detect a motor revolving speed that is a revolving speed of each of the ...

Hydraulic Energy Regeneration System for Work Machine

A hydraulic fluid energy regeneration system for a work machine capable of securely maintaining a brake pressure even when a solenoid valve or the like is erroneously rendered open by an electrical failure is provided. The hydraulic fluid energy regeneration system for a work machine, including a first hydraulic actuator; a second hydraulic actuator; and a first hydraulic pump that supplies a hydraulic fluid to the first hydraulic actuator via a first hydraulic line, includes: an upper control valve that is connected to a discharge side on which the hydraulic fluid is discharged from the second hydraulic actuator when an object to be driven by the second hydraulic actuator falls under its own weight, and that can regulate a flow rate of the hydraulic fluid discharged from the second hydraulic actuator; a communication hydraulic line that connects the upper control valve to a hydraulic fluid tank; a lower control valve that is provided in the communication hydraulic line and that can regulate a flow rate of the hydraulic fluid discharged from the upper control valve to the hydraulic fluid tank; and a regeneration hydraulic line that has one end side connected to a branch section between the upper control valve and the lower control valve in the communication hydraulic line and that has an other end side connected to the first hydraulic line. 1. A hydraulic fluid energy regeneration system for a work machine , including a first hydraulic actuator; a second hydraulic actuator configured with a hydraulic cylinder different from the first hydraulic actuator; a first hydraulic pump that supplies a hydraulic fluid to the first hydraulic actuator via a first hydraulic line; and a hydraulic fluid tank , the hydraulic fluid energy regeneration system comprising:an upper control valve that is connected to a discharge side on which the hydraulic fluid is discharged from the second hydraulic actuator when an object to be driven by the second hydraulic actuator falls under an own ...

HYDRAULIC CONTROL APPARATUS AND METHOD

A shovel is disclosed, which includes a lower traveling body; an upper rotating body mounted on the lower traveling body; an engine mounted on the upper rotating body; a hydraulic pump of a variable volume type; a hydraulic actuator to which pressurized oil is supplied from the hydraulic pump; a flow rate control valve configured to control, based on operation amount of an operation member, a flow rate of the oil to the hydraulic actuator from the hydraulic pump; and a controller configured to control the hydraulic pump. The controller calculates a virtual bleed flow rate from a bleed opening area of the flow rate control valve, determines a pump demand flow rate based on the calculated virtual bleed flow rate, and performs a virtual bleed-off control such that a discharge flow rate of the hydraulic pump becomes the determined pump demand flow rate. 1. A shovel; comprising:a lower traveling body;an upper rotating body mounted on the lower traveling body;an engine mounted on the upper rotating body;a hydraulic pump of a variable volume type;a hydraulic actuator to which pressurized oil is supplied from the hydraulic pump;a flow rate control valve configured to control, based on operation amount of an operation member, a flow rate of the oil to the hydraulic actuator from the hydraulic pump; anda controller configured to control the hydraulic pump, whereinthe controller calculates a virtual bleed flow rate from a bleed opening area of the flow rate control valve, determines a pump demand flow rate based on the calculated virtual bleed flow rate, and performs a virtual bleed-off control such that a discharge flow rate of the hydraulic pump becomes the determined pump demand flow rate.2. The shovel of claim 1 , wherein the virtual bleed flow rate is calculated based on the bleed opening area and a discharge pressure of the hydraulic pump.3. The shovel of claim 1 , wherein the bleed opening area is calculated based on the operation amount.4. The shovel of claim 3 , ...

WORKING VEHICLE AND WORKING VEHICLE CONTROL METHOD

A working vehicle is provided with a hydraulic pump is driven using an engine. A hydraulic actuator is driven using hydraulic fluid which is discharged from the hydraulic pump. A power generator motor driven using the engine. An electric actuator is driven using electrical power which is generated using the power generator motor. An exhaust processing apparatus cleans exhaust from the engine. A reducing agent tank retains reducing agent which is supplied to the exhaust processing apparatus. A retention amount detecting section detects the retention amount of the reducing agent inside the reducing agent tank. An engine control section performs output restriction control where the output of the engine is reduced when the retention amount is equal to or less than a first threshold. The electric actuator control section restricts the output of the electric actuator during executing of the output restriction control. 1. A working vehicle comprising:an engine;a hydraulic pump driven by the engine;a hydraulic actuator driven by a hydraulic fluid discharged from the hydraulic pump;a power generator driven by the engine;an electric actuator driven by electrical power generated by the power generator;an exhaust processing apparatus which cleans an exhaust from the engine;a reducing agent tank which retains a reducing agent supplied to the exhaust processing apparatus;a retention amount detecting section which detects a retention amount of the reducing agent inside the reducing agent tank;an engine control section which performs an output restriction control in which an output of the engine is reduced when the retention amount is equal to or less than a first threshold; andan electric actuator control section which restricts an output of the electric actuator during executing of the output restriction control: andan electrical power control apparatus electrically connected with the power generator and the electric actuator,the electric actuator control section stopping the ...

Electric work machine

An excavator comprising: a battery; an electric motor having the battery as the drive power source therefor; a hydraulic actuator having a hydraulic pump driven by the electric motor as the oil pressure source therefor; a cut-off lever that limits operation of the hydraulic actuator by cutting off pilot pressure that operates the hydraulic actuator; an electric cooling pump that circulates cooling water through a cooling water path for cooling electrical equipment including the battery and the electric motor; an electric cooling fan that blows cooling air on to a radiator provided on the cooling water path; and a system controller that, if the cut-off lever is rotated upwards and a command to limit the hydraulic actuator is received, stops the electric motor, the cooling pump, and the cooling fan.

WORKING MACHINE

A working machine includes a prime mover, a hydraulic pump to be driven by power of the prime mover and to output operation fluid, a hydraulic actuator to be operated by the operation fluid, and a control device. The control device has a revolving-speed controller to increase and decrease a revolving speed of the prime mover, a first setting portion to set a limit value of the revolving speed of the prime mover, and a revolving-speed limiter to limit the revolving speed of the prime mover set by the revolving-speed controller to the limit value set by the first setting portion. 1. A working machine comprising:a prime mover;a hydraulic pump to be driven by power of the prime mover and to output operation fluid;a hydraulic actuator to be operated by the operation fluid; and a revolving-speed controller to increase and decrease a revolving speed of the prime mover;', 'a first setting portion to set a limit value of the revolving speed of the prime mover; and', 'a revolving-speed limiter to limit the revolving speed of the prime mover set by the revolving-speed controller to the limit value set by the first setting portion., 'a control device having2. The working machine according to claim 1 , set the limit values corresponding to at least two hydraulic actuators to values different from each other when the limit values are set for each of the hydraulic actuator; and', 'set the limit values corresponding to at least two working contents to values different from each other when the limit values are set for each of the hydraulic actuator., 'wherein the first setting portion sets the limit value for each of the hydraulic actuator or for each of working contents, the first setting portion being configured to3. The working machine according to claim 1 , comprising the first state allowing the revolving speed of the prime mover to be increased and decreased by the revolving speed limiter; and', 'the second state preventing the revolving speed of the prime mover from being ...

CONSTRUCTION MACHINE

An engine () electronically controlled by a control device (), a hydraulic motor () for traveling which is driven by a pressurized oil delivered from a hydraulic pump (), and a traveling speed switching member () which switches a traveling speed by the hydraulic motor () at least in two stages of a low speed and a high speed. The control device () includes an output lowering determination unit for determining whether or not a fuel injection amount to be supplied to the engine () is limited and an engine output is in a lowered state and a low-speed control unit in which, when the engine () output is in a lowered state, a traveling speed is controlled to a low speed state kept lower than a high speed even if the traveling speed switching member () has been switched to the high speed side. 1. A construction machine comprising:{'b': '2', 'an automotive vehicle body ();'}{'b': 10', '2', '33, 'an engine () mounted on said vehicle body () and electronically controlled by a control device ();'}{'b': 13', '10, 'a hydraulic pump () which is driven by said engine () and sucks an oil liquid in a tank and delivers a pressurized oil;'}{'b': 24', '13, 'a hydraulic motor () for traveling which is driven by the pressurized oil delivered from said hydraulic pump ();'}{'b': 27', '2', '24, 'a traveling operation device () provided on said vehicle body () and driving and operating said hydraulic motor () during traveling; and'}{'b': 29', '2', '24, 'a traveling speed switching member () which is provided on said vehicle body () and switches a traveling speed by said hydraulic motor () at least in two stages of a low speed and a high speed, characterized in that{'b': '33', 'said control device () includes{'b': '10', 'an output lowering determination unit for determining whether or not a fuel injection amount to be supplied to said engine () is limited and an engine output is in a lowered state; and'}{'b': 10', '27', '29, 'a low-speed control unit in which, when it is determined by said ...

Hydraulic Driving System for Construction Machine

In a hydraulic driving system for construction machines, when track motors and are operated and the delivery pressure of a main pump increases to a second value PS2 of the set pressure of a main relief valve , the set pressure of a signal pressure relief valve increases from a third value PA1 to a fourth value PA2, which is smaller than the second value PS2 of the set pressure of the main relief valve , the difference between the second value PS2 and the fourth value PA2 being smaller than the target LS differential pressure. With such a structure, even if one of actuators reaches the stroke end and the delivery pressure of the hydraulic pump rises to the set pressure of the main relief valve, the other actuators do not stop, and further when the main relief valve is configured to increase the set pressure during operation of a specific actuator, the load pressure of the specific actuator does not increase to the increased set pressure of the main relief valve. 1. A hydraulic driving system for a construction machine , comprising:a hydraulic pump of variable displacement type driven by a prime mover;a plurality of actuators each driven by a hydraulic fluid delivered from the hydraulic pump;a plurality of flow control valves that each control a flow rate of the hydraulic fluid supplied from the hydraulic pump to a corresponding one of the plurality of actuators;a plurality of pressure compensating valves each for controlling a differential pressure across a corresponding one of the flow control valves independently such that the differential pressure across the corresponding flow control valve equals a target compensation differential pressure;a pump control device for controlling a capacity of the hydraulic pump by load-sensing control such that a delivery pressure of the hydraulic pump becomes higher by a target differential pressure than a highest load pressure of the plurality of actuators;a main relief valve that limits a maximum pressure of the delivery ...

Construction Machine

Flow control over a hydraulic pump and flow dividing control of a plurality of directional control valves associated with actuators can stably be exercised even in a case in which differential pressures across the directional control valves are quite low, an abrupt change in a flow rate of the hydraulic fluid supplied to each actuator is prevented and excellent combined operability is realized even in an abrupt change in a demanded flow rate at a time of transition from a combined operation to a sole operation, and realizing excellent combined operability, and a meter-in loss in each directional control valve is reduced to realize high energy efficiency. Demanded flow rates of the directional control valves are calculated from input amounts of operation levers, openings of flow control valves are controlled using the demanded flow rates, a meter-in pressure loss of a predetermined directional control valve is calculated from the demanded flow rates and meter-in opening areas of the directional control valves, and a set pressure of an unloading valve is controlled using a value of the meter-in pressure loss. 15. to . (canceled)6. A construction machine provided with a hydraulic drive system comprising:a variable displacement hydraulic pump;a plurality of actuators driven by a hydraulic fluid delivered from the hydraulic pump;a control valve device that distributes and supplies the hydraulic fluid delivered from the hydraulic pump to the plurality of actuators;a plurality of operation lever devices that instructs drive directions and speeds of the plurality of actuators, respectively;a pump regulating device that controls a delivery flow rate of the hydraulic fluid from the hydraulic pump in such a manner that the hydraulic fluid is delivered at a flow rate to match with input amounts of operation levers of the plurality of operation lever devices;an unloading valve that discharges the hydraulic fluid in a hydraulic fluid supply line of the hydraulic pump to a tank ...

HYDRAULIC CONTROL SYSTEM

A hydraulic control system is provided in which hydraulic oil discharged from a variable displacement hydraulic pump is controlled and supplied to a hydraulic actuator by a closed center control valve activated based on operation input from an operation device, thereby controlling activation of the hydraulic actuator. With the pump displacement detected by pump displacement detecting means and the pump output pressure detected by pump output pressure detecting means being used as feedback input and the characteristic value determined by the operation input and the feedback input being used as a target value of a control loop, variable displacement control is performed by a controller provided with a horsepower control loop, a pressure control loop, a flow rate control loop, and a minimum pressure holding loop that feed back a calculated value based on the feedback input or the feedback input itself. 17-. (canceled)8. A hydraulic control system in which hydraulic oil discharged from a variable displacement hydraulic pump is controlled and supplied to a hydraulic actuator by a closed center control valve activated based on operation input from an operation device thereby controlling activation of the hydraulic actuator ,the hydraulic control system comprising:pump displacement detecting means for detecting a displacement of the hydraulic pump; andpump output pressure detecting means for detecting an output pressure of the hydraulic pump,the hydraulic pump being configured such that, with a pump displacement detected by the pump displacement detecting means and a pump output pressure detected by the pump output pressure detecting means being used as feedback input and a characteristic value determined by the operation input and the feedback input being used as a target value of a control loop, variable displacement control is performed by a controller provided with a horsepower control loop, a pressure control loop, a flow rate control loop, and a minimum pressure ...

Hydraulic Control System for Working Machine

To provide a hydraulic control system for a working machine with high fuel efficiency and higher versatility to be capable of being adapted to special work. The hydraulic control system for the working machine according to the present invention includes: a plurality of directional control valves ( 31, 32, . . . ), more than one of which is connected in parallel to each of a plurality of hydraulic pumps ( 11, 12, 13 ) to supply hydraulic oil from the hydraulic pump to each of the corresponding actuators ( 4, 5, 6, 50 ); operating devices ( 110, 120, 130, 140 ) to which an operator inputs manipulated variables; a connection map ( 182 ) storing a precedence order for connection between a plurality of hydraulic pumps and a plurality of directional control valves; and a controller ( 100 ) controlling the connection conditions of the pumps and the actuators on the basis of the connection a¥map and operation signals.

WORK VEHICLE, CONTROL DEVICE FOR WORK VEHICLE, AND CONTROL METHOD FOR WORK VEHICLE

A work vehicle controls an engine output based on an accelerator operation amount and a work equipment operation amount. A control device for the work vehicle includes an acceleration correction unit, a target vehicle speed determination unit, and a deceleration correction unit. The acceleration correction unit obtains a corrected accelerator operation amount by correcting the accelerator operation amount based on an inching operation amount. The target vehicle speed determination unit determines a target vehicle speed based on the corrected accelerator operation amount and a signal based on an operation of a shift operation member. The deceleration correction unit corrects the target vehicle speed based on the inching operation amount. 1. A control device for a work vehicle that controls an engine output based on an accelerator operation amount and a work equipment operation amount , the control device comprising:an acceleration correction unit that obtains a corrected accelerator operation amount by correcting the accelerator operation amount based on an inching operation amount; the corrected accelerator operation amount and', 'a signal based on an operation of a shift operation member; and, 'a target vehicle speed determination unit that determines a target vehicle speed based on'}a deceleration correction unit that corrects the target vehicle speed based on the inching operation amount.2. The control device for a work vehicle according to claim 1 , further comprising: the accelerator operation amount and', 'the work equipment operation amount., 'a target engine speed determination unit that determines a target engine speed based on'}3. A work vehicle including the control device according to claim 1 , the work vehicle further comprising:an engine;a transmission that shifts an output of the engine;a work equipment pump driven by the engine;work equipment driven by hydraulic oil discharged from the work equipment pump;an accelerator operation member;an inching ...

Construction Machine and Method for Reporting Quality of Driving Operations of Construction Machine

A construction machine provided with an exhaust gas purifying device for an internal combustion engine includes an energy-wasting operation judging unit that judges whether or not an operation of the construction machine is an energy-wasting operation, a judgment result notifier that notifies a judgment result of the energy-wasting operation judging unit to an outside, a regeneration treatment judging unit that judges whether or not a regeneration treatment of the exhaust gas purifying device is to be conducted, and a notification restricting unit that restricts the judgment result notifier from notifying the judgment result of the energy-wasting operation judging unit when the regeneration treatment judging unit judges that the regeneration treatment of the exhaust gas purifying device is to be conducted.

Hydraulic control system for construction machinery

A hydraulic control system for a construction machine is disclosed, which can operate an arm cylinder and a bucket cylinder by supplying hydraulic fluid from respective hydraulic pumps to the arm cylinder and the bucket cylinder during a combined operation, such as an excavating work, in which an arm joystick and a bucket joystick are simultaneously operated. The hydraulic control system includes a first arm control valve installed in a flow path between the first hydraulic pump and the arm cylinder and shifted to control a start, stop, and direction change of the arm cylinder in response to an operation of the arm joystick, a second arm control valve installed in a flow path between the second hydraulic pump and the arm cylinder and shifted to make discharged hydraulic fluid of the second hydraulic pump join hydraulic fluid of the arm cylinder to be supplied if a control signal according to the operation of the arm joystick exceeds a set value, a bucket control valve installed in a path between the second hydraulic pump and the bucket cylinder and shifted to control a start, stop, and direction change of the bucket cylinder in response to the operation of the bucket joystick, and a confluence cutoff proportional valve installed in a path between the second hydraulic pump and the second arm control valve.

WORK MACHINE AND CONTROL METHOD FOR WORK MACHINE

A work machine according an aspect includes a work implement, an operation apparatus for operating the work implement, and a controller for controlling the work implement. The controller performs intervention control for raising the work implement based on an operation command from the operation apparatus, decides switching from the intervention control to control of the work implement in accordance with an operation command from the operation apparatus, when the operation command from the operation apparatus is the operation command for raising the work implement or the neutral command based on a result of the determination, and makes an adjustment to gradually change the rising target speed of the work implement to the target speed in accordance with the operation command from the operation apparatus when the speed difference is greater than or equal to a predetermined value. 1. A work machine comprising:a work implement;an operation apparatus for operating the work implement; and performs intervention control for raising the work implement based on an operation command from the operation apparatus,', 'decides switching from the intervention control to control of the work implement in accordance with an operation command from the operation apparatus,', 'determines whether or not the operation command from the operation apparatus for the switching performed based on a result of the decision is an operation command for raising the work implement, or a neutral command,', 'determines a speed difference between a rising target speed of the work implement in the intervention control and a target speed in accordance with the operation command from the operation apparatus when the operation command from the operation apparatus is the operation command for raising the work implement or the neutral command based on a result of the determination, and', 'makes an adjustment to gradually change the rising target speed of the work implement to the target speed in accordance ...

WORK MACHINE AND CONTROL METHOD FOR WORK MACHINE

A work machine according to an aspect includes: a dipper stick; a boom; a cylinder for driving the boom; an operation apparatus for operating the dipper stick; and a controller for performing intervention control by using the boom in accordance with an operation command issued from the operation apparatus to achieve land grading. The controller determines whether or not the operation command from the operation apparatus indicates an amount greater than or equal to a predetermined amount, and corrects a speed of the cylinder when the operation command from the operation apparatus indicates an amount greater than or equal to the predetermined amount. 1. A work machine comprising:a dipper stick;a boom;a cylinder for driving the boom;an operation apparatus for operating the dipper stick; and determines whether or not the operation command from the operation apparatus indicates an amount greater than or equal to a predetermined amount, and', 'corrects a speed of the cylinder when the operation command from the operation apparatus indicates an amount greater than or equal to the predetermined amount., 'a controller for performing intervention control by using the boom in accordance with an operation command issued from the operation apparatus to achieve land grading, wherein the controller'}2. The work machine according to claim 1 , further comprising a memory storing a first conversion table referred to for calculating a first shift amount of a spool of a direction control valve for supplying hydraulic oil to the cylinder claim 1 , and a second conversion table referred to for calculating a second shift amount of the spool claim 1 , the second shift amount being different from the first shift amount claim 1 , wherein the controllercalculates a target speed of the cylinder based on a target speed of the boom,calculates a shift amount of the spool based on a calculated target speed of the cylinder with reference to the first conversion table when the operation command from ...

WORK VEHICLE AND METHOD OF CONTROLLING THE SAME

A work vehicle includes: a hydraulic operation apparatus for operating an actuator; a main controller configured to generate a command current in accordance with an amount of operation of the operation apparatus; an electromagnetic proportional control valve configured to generate command pilot pressure in accordance with the command current; and a main valve configured to adjust a flow rate of hydraulic oil for operating the actuator based on the command pilot pressure. The electromagnetic proportional control valve is provided in a pilot oil passage that connects a pilot pump and a main valve, and configured to utilize hydraulic pressure supplied from the pilot pump to generate command pilot pressure. The operation apparatus is provided in an operation apparatus oil passage that is different from the pilot oil passage. 1. A work vehicle comprising:a hydraulic operation apparatus for operating an actuator;a controller configured to generate a command current in accordance with an amount of operation of the operation apparatus;an electromagnetic proportional control valve configured to generate command pilot pressure in accordance with the command current; anda valve configured to adjust a flow rate of hydraulic oil for operating the actuator based on the command pilot pressure,the electromagnetic proportional control valve being provided in a first oil passage that connects a hydraulic pressure source and the valve, and being configured to utilize hydraulic pressure supplied from the hydraulic pressure source to generate the command pilot pressure,the operation apparatus being provided in a second oil passage that is different from the first oil passage.2. The work vehicle according to claim 1 , wherein oil is supplied to the operation apparatus from the hydraulic pressure source through the second oil passage.3. The work vehicle according to claim 1 , further comprising a tank in which oil utilized by the hydraulic pressure source is stored claim 1 , whereinoil ...

Turn-driving apparatus for work machine

A turn-drive apparatus capable of securing high acceleration at the time of turning start with a reduced relief loss includes a hydraulic pump of a variable capacity type, a turning motor, a turning control device, a relief valve, and a flow rate control device that controls a pump flow rate. The flow rate control device calculates a relief-cut-control target pump flow rate on the basis of the sum of a minimum relief flow rate and a turning-speed flow rate, and inputs a pump capacity command to the variable capacity-type hydraulic pump based thereon. The flow rate control device makes the relief-cut-control target pump flow rate larger than the sum of the minimum relief flow rate and the turning-speed flow rate at the time of turning start.

Construction machine hydraulic drive system having exhaust gas purifying device

A construction machine hydraulic drive system that performs load sensing control is capable of efficiently burning and removing deposits on a filter in an exhaust gas purifying device through pump output increasing control and to be free from faults in the pump output increasing control even when an actuator is operated during the pump output increasing control. A solenoid switching valve is switched so that output pressure of an engine speed detecting valve is guided to a pressure receiving portion of an LS control valve and a pressure receiving portion of an unloading valve when a start of regeneration is not directed, and delivery pressure of a pilot pump is guided to the pressure receiving portion and the pressure receiving portion when the start of the regeneration is directed, to thereby disable load sensing control to increase capacity of a main pump and increase set pressure of the unloading valve.

Working Machine

A working machine includes a ground engaging structure, and an undercarriage supported on the ground engaging structure. The undercarriage has a drive arrangement for moving the ground engaging structure to propel the working machine, the drive arrangement comprising a prime mover and a transmission comprising a hydraulic pump arrangement configured to be driven by the prime mover. A superstructure rotatably mounted to the undercarriage and a working arm is connected to the superstructure. A first implement mount connected the undercarriage for operably mounting a working implement to the undercarriage. The undercarriage has a first actuator for raising and lowering a working implement when mounted to the first implement mount and comprises a hydraulic connector for supplying hydraulic fluid to the first actuator to actuate the first actuator, and a first auxiliary hydraulic connector is provided that is configured for supplying hydraulic fluid to an implement connected thereto. 1. A working machine comprising:a ground engaging structure provided in the form of front and rear wheels or a pair of endless tracks;an undercarriage supported on the ground engaging structure, the undercarriage comprising a drive arrangement for moving the ground engaging structure to propel the working machine, the drive arrangement comprising a prime mover and a transmission comprising a hydraulic pump arrangement configured to be driven by the prime mover;a superstructure rotatably mounted to the undercarriage;a working arm connected to the superstructure; anda first implement mount connected the undercarriage for operably mounting a working implement to the undercarriage,wherein the undercarriage comprises a first actuator for raising and lowering a working implement when mounted to the first implement mount and comprises a hydraulic connector for supplying hydraulic fluid to the first actuator to actuate the first actuator, and wherein the undercarriage comprises a first auxiliary ...

DRIVE MOTOR DISPLACEMENT CONTROL

A power machine can include a hydraulic drive system that includes an infinitely variable hydraulic drive motor. A run-time displacement of the hydraulic motor can be adjusted based on commanded travel speed or based on a output torque. In some case, the run-time displacement can be selected from one of a plurality of displacement ranges, such as a high range and a low range. 1. A power machine having an frame , an power source supported by the frame , and a power conversion system including hydraulic drive system operably coupled to the power source and configured to power at least one tractive element , the hydraulic drive system comprising:a hydraulic circuit that includes a hydraulic pump in hydraulic communication with a hydraulic motor, the hydraulic motor being configured to operate with infinitely variable displacement to drive the power machine; and determine a control value based on one or more of: a commanded travel speed for the power machine or a pressure in the hydraulic circuit; and', 'changing a run-time displacement of the hydraulic motor based upon the determined control value., 'a control device that is configured to2. The power machine of claim 1 , wherein the hydraulic motor is configured to operate selectively in a first displacement range and in a second displacement range;wherein a maximum displacement of the first displacement range is the same as a maximum displacement of the second displacement range; andwherein a minimum displacement of the first displacement range is smaller than a minimum displacement of the second displacement range.3. The power machine of claim 2 , wherein the control device is configured to implement claim 2 , as a default claim 2 , operation of the hydraulic motor at the maximum displacement of the first displacement range or the second displacement range claim 2 , regardless of whether the first displacement range or the second displacement range is selected.4. The power machine of claim 1 , wherein the control ...

ELECTRO-HYDRAULIC SYSTEM WITH NEGATIVE FLOW CONTROL

A fluid power system includes an electro-hydraulic variable displacement fluid pump driving fluid at a first displacement value. The system further includes a directional control valve, a sensor, and a controller. The directional control valve includes a valve member movable between a neutral position and at least one actuated position. The directional control valve diverts at least some fluid to an actuator while the valve member is in an actuated position, and the directional control valve exhausts fluid at an exhaust pressure through an outlet port to the fluid reservoir while the valve member is in the neutral position. The sensor measures a difference between the exhaust pressure and a nominal pressure and generates a signal based on the measured difference. The controller generates a flow command at least partially based on the pressure signal to modify the operation of the pump to drive fluid at a second displacement value. 1. A fluid power system comprising:an electro-hydraulic variable displacement fluid pump configured to receive fluid from a fluid reservoir and drive the fluid at a first displacement value;a directional control valve including an inlet port and at least one outlet port, the inlet port configured to receive the fluid from the pump, the directional control valve further including a valve member movable between a neutral position and at least one actuated position, the directional control valve configured to divert at least some fluid to an actuator while the valve member is in the at least one actuated position, the directional control valve further configured to exhaust fluid at an exhaust pressure through one of the at least one outlet ports to the fluid reservoir while the valve member is in the neutral position;a sensor for measuring a difference between the exhaust pressure and a nominal pressure, the sensor configured to generate a pressure signal based on the difference between the exhaust pressure and the nominal pressure; anda ...

HYDRAULIC DRIVE SYSTEM FOR ELECTRICALLY-OPERATED HYDRAULIC WORK MACHINE

An electrically-operated hydraulic work machine drives an actuator with a hydraulic pump driven by an electric motor and exercises load sensing control by controlling the rotation speed of the electric motor. The useful life of an electrical storage device, which is an electrical power source for the electric motor, is increased by suppressing the horsepower consumption of the hydraulic pump. This prolongs the operating time of the electrically-operated hydraulic work machine, and reduces the size of the electric motor. A controller exercises load sensing control over a variable displacement main pump by controlling the rotation speed of the electric motor, and provides the main pump with a torque control device that reduces the delivery rate of the main pump when the delivery pressure of the main pump increases, or provides the controller with a control algorithm that performs the same function as the torque control device. 1. A hydraulic drive system for an electrically-operated hydraulic work machine , the work machine havingan electric motor,a hydraulic pump driven by the electric motor,a plurality of actuators driven by a hydraulic fluid discharged from the hydraulic pump,a plurality of flow control valves for controlling a flow rate of the hydraulic fluid supplied from the hydraulic pump to the actuators,an electrical storage device for supplying electrical power to the electric motor,an electric motor rotation speed control system for controlling a rotation speed of the electric motor, anda torque control device for controlling an absorption torque of the hydraulic pump,wherein the electric motor rotation speed control system is configured to control the rotation speed of the electric motor in such a manner that the delivery pressure of the hydraulic pump is higher than the highest load pressure of the actuators by a target differential pressure when the electric motor is driven to drive the hydraulic pump, andthe torque control device is configured to ...

WORK VEHICLE AND METHOD OF CONTROLLING WORK VEHICLE

A work vehicle is provided with an engine, a variable displacement hydraulic pump, a hydraulic motor, a traveling apparatus, an exhaust treatment device, a reductant supply route, a controller, and an operation member. The variable displacement hydraulic pump is configured to discharge hydraulic oil when driven by the engine. The exhaust treatment device is configured to treat the exhaust from the engine. The reductant supply route supplies a reductant to the exhaust treatment device. The controller is configured to set an engine speed to a low idle when the reductant supply route gets into an abnormal state. The operation member is configured to indicate a change of a discharge capacity of the variable displacement hydraulic pump so that the travel speed of the traveling apparatus becomes a predetermined speed or greater when the reductant supply route gets into an abnormal state. 1. A work vehicle comprising:an engine;a variable displacement hydraulic pump configured to discharge hydraulic oil when driven by the engine;a hydraulic motor driven by the hydraulic oil discharged from the variable displacement hydraulic pump;a traveling apparatus driven by the hydraulic motor;an exhaust treatment device configured to treat exhaust from the engine;a reductant supply route supplying a reductant to the exhaust treatment device;a controller configured to set an engine speed to a low idle when the reductant supply route gets into an abnormal state; andan operation member configured to indicate a change of a discharge capacity of the variable displacement hydraulic pump so that the travel speed of the traveling apparatus becomes a predetermined speed or greater when the reductant supply route is in an abnormal state.2. The work vehicle according to claim 1 , further comprisinga hydraulic circuit configured to change the discharge capacity of the variable displacement hydraulic pump; anda fixed displacement hydraulic pump driven by the engine, the fixed displacement hydraulic ...

WORK MACHINE

A work machine including a front control section configured to calculate a limit command value for restricting an operation of a front work implement includes: for example, a bypass line that bypasses, for example, the proportional solenoid valve in, for example, the pilot line; for example, a bypass valve disposed in, for example, the bypass line; a switch configured to output a signal to turn on or off control by the front control section; an on/off determining part configured to determine whether the signal from the switch is an on signal that brings front control into an on state or an off signal that brings the front control into an off state; an open/close command part configured to generate an open/close command signal to open the bypass valve when the signal is determined to be the off/off signal. 1. A work machine including a machine body , a front work implement disposed in the machine body , a plurality of hydraulic actuators configured to drive the front work implement , a posture sensor configured to detect posture of the front work implement , a hydraulic pump , a pilot pump , a plurality of control valves configured to control a flow of hydraulic working fluid to be supplied from the hydraulic pump to the hydraulic actuators associated with the respective control valves , operation lever devices configured to generate hydraulic signals directing operations of the hydraulic actuators associated with the respective operation lever devices in response to a control operation , a plurality of pilot lines configured to connect the operation lever devices with hydraulic drive parts of the control valves associated with the respective operation lever devices , a proportional solenoid valve disposed in at least one of the pilot lines , and a front control section configured to calculate a limit command value for restricting operations of the front work implement through control of the proportional solenoid valve using a detection signal of the posture sensor , ...

Work vehicle and method of controlling work vehicle

A work vehicle includes an engine, a variable displacement hydraulic pump, a hydraulic motor, an exhaust treatment device, and a controller. The engine drives the variable displacement hydraulic pump. The variable displacement hydraulic pump is able configured to change the discharge direction of the hydraulic fluid. Depending on the discharge direction of the hydraulic oil from the variable displacement hydraulic pump, the hydraulic motor is configured to change the driving direction to the forward direction or the reverse direction. The exhaust treatment device is configured to treat the exhaust from the engine. The controller is configured to increase the speed of the engine to a predetermined first speed or greater and to change the discharge direction of the variable displacement hydraulic pump to a neutral state during regeneration of the exhaust treatment device.

Construction Machine

The invention provides a construction machine in which the load torque at the time of engine start-up can be reduced even when the engine stops against the will of the operator. A hydraulic excavator includes a control device () having a pump displacement control section () and an unload control section (). The pump displacement control section () makes the displacement of a hydraulic pump () variable to a minimum displacement by controlling a regulator device () when the speed of an engine () detected by a speed sensor () becomes equal to or less than a preset low speed N at the time of driving of the engine (). The unload control section () controls an unloading valve () to the open position at the time of start-up of the engine (). 1. A construction machine comprising:an engine;a speed sensor for detecting a speed of the engine;a hydraulic pump of a variable displacement type driven by the engine;a hydraulic actuator;a directional control valve for controlling a flow of hydraulic fluid from the hydraulic pump to the hydraulic actuator based on an operation of an operating member;a pilot pump of a fixed displacement type driven by the engine;a regulator device configured to make a displacement of the hydraulic pump variable with using a delivery pressure of the pilot pump;an unloading valve provided on a line connecting a delivery side of the pilot pump to a tank, the unloading valve being switchable between an open position and a closed position; anda control device including a pump displacement control section configured to control the displacement of the hydraulic pump by controlling the regulator device and an unload control section configured to control the unloading valve to the open position at a time of start-up of the engine,wherein the pump displacement control section is configured to:store a low speed preset for the engine, the low speed being smaller than a minimally required idle speed of the engine necessary to obtain a delivery pressure of the ...

HYDRAULIC DRIVE DEVICE FOR OPERATING MACHINE

A hydraulic drive apparatus capable of automatic control with high accuracy regardless of regeneration operation includes a boom flow rate control valve, an arm flow rate control valve, a regeneration control valve, a pump control device for performing horsepower control, a posture detection device, a boom flow rate control device switchable between a normal control mode and an automatic control mode, and a regeneration control device. The boom flow rate control device adjusts the boom flow rate in the automatic control mode so that a work attachment moves along a target locus. The regeneration control device sets the regeneration control valve to a regeneration position in a low load situation and to a regeneration cut position in a high load situation, and lowers the regeneration rate in the low load situation when the boom flow rate control device is switched to the automatic control mode. 1. A hydraulic drive apparatus provided in a work machine equipped with a machine body and a work device , the work device including a boom supported by the machine body so as to be raiseable and lowerable , an arm connected to a distal end of the boom rotationally movably , and a work attachment attached to a distal end of the arm , to hydraulically drive the boom and the arm , the hydraulic drive apparatus comprising:a hydraulic fluid supply device including at least one variable displacement type hydraulic pump that is driven by a drive source to thereby discharge hydraulic fluid;a boom cylinder that is expanded and contracted by supply of the hydraulic fluid from the hydraulic fluid supply device to raise and lower the boom;an arm cylinder that is expanded and contracted by supply of hydraulic fluid from the hydraulic fluid supply device to rotationally actuate the arm, the arm cylinder having a head-side chamber and a rod-side chamber opposite to the head-side chamber, the arm cylinder connected to the arm so as to be expanded by supply of the hydraulic fluid to the head- ...

DISTRIBUTED HYDRAULIC SYSTEM

Disclosed embodiments are directed to distributed hydraulic systems, and power machines such as excavators including distributed hydraulic systems. In the distributed hydraulic systems, electronically controlled distributor blocks are located throughout the machine, particularly along the lift arm, to locally distribute hydraulic power to actuators of the various machine and implement functions. Distributing control of hydraulics in multiple locations reduces the number of hoses that must be routed from a main control valve to the various actuators on the machine. 1. A power machine comprising:a frame having a first frame portion;a lift arm structure pivotally coupled to the first frame portion such that the lift arm structure can be raised and lowered;first hydraulic system components positioned on the first frame portion, the first hydraulic system components including at least one hydraulic pump configured to selectively provide pressurized hydraulic fluid;a supply hose configured to carry pressurized hydraulic fluid from the at least one hydraulic pump;a return hose configured to carry a return flow of hydraulic fluid;second hydraulic system components, the second hydraulic system components including a first electronically controlled hydraulic flow distributor block positioned on the lift arm structure, the first electronically controlled hydraulic flow distributor block configured to receive the pressurized hydraulic fluid from the supply hose and to selectively divert the pressurized hydraulic fluid to different ones of multiple actuators on the lift arm structure; andan electronic controller positioned on the frame and configured to control the first electronically controlled hydraulic flow distributor block to control the different ones of the multiple actuators on the lift arm structure.2. The power machine of claim 1 , wherein the frame includes an undercarriage claim 1 , and wherein the first frame portion comprises a house pivotally mounted on the ...

DUAL PRESSURE LOGIC FOR A TRACK DRILL CIRCUIT

A hydraulic circuit may be used for controlling a plurality of hydraulic implements. The hydraulic circuit may include a first directional valve, a second directional valve, and a relief valve. A variable displacement pump may be fluidly coupled to the first directional valve, the second directional valve, and the relief valve. The hydraulic circuit may be communicably and operably coupled to a controller, and the controller may be programmed to selectably control the hydraulic circuit between a first operational mode and a second operational mode. Additionally, the controller may be programmed to actuate the first directional valve between an open position and a closed position and to actuate the second directional valve between a first open position, a second open position, a first closed position and a second closed position. 1. A hydraulic circuit having a variable hydraulic pressure , the hydraulic circuit comprising:a reservoir configured to store a hydraulic fluid;a variable displacement pump being selectable between a first operational mode and a second operational mode, and the variable displacement pump configured to pump the hydraulic fluid through a hydraulic fluid line;a first hydraulic implement and a second hydraulic implement fluidly connected to the hydraulic fluid line and the first hydraulic implement and the second hydraulic implement configured to receive the hydraulic fluid from the variable displacement pump;a first directional valve coupled to the hydraulic fluid line, the first directional valve having an open positon for fluidly connecting the first hydraulic implement and a relief valve to the variable displacement pump, an output of the relief valve being fluidly connected to a return line of the reservoir, and the first directional valve having a closed position for fluidly disconnecting the first hydraulic implement and the relief valve from the variable displacement pump; anda second directional valve coupled to the hydraulic fluid ...

Hydraulic control apparatus and method

A hydraulic control apparatus is disclosed that controls a hydraulic pump in a construction machine in which a hydraulic actuator is connected to the hydraulic pump via a directional control valve of a closed center type, and in which a position of the directional control valve is changed according to an operation amount of an operation member. The hydraulic control apparatus includes a virtual negative control pressure calculating part configured to calculate, based on the operation amount of the operation member and a discharge pressure of the hydraulic pump, a virtual negative control pressure when a negative control system is assumed; and a part configured to calculate a control command value for the hydraulic pump based on the virtual negative control pressure.

TEMPERATURE RESPONSIVE HYDRAULIC DERATE

A work machine includes a mechanical arm and a hydraulic actuator coupled to the mechanical arm to move the arm between a first position and a second position. A valve is in fluid communication with the hydraulic actuator for supplying fluid to the hydraulic actuator. A pump is configured to discharge fluid to the valve. An engine is operatively connected to the pump. A coolant system is in thermal communication with the engine and includes a temperature sensor. A controller is in communication with the pump and the temperature sensor. The controller is configured to transmit a control signal to the pump to modify a flowrate of the pump and to adjust the flowrate of the pump in response to a signal from the temperature sensor that a temperature is at or above a set temperature value. 1. A work machine comprising:a mechanical arm;a hydraulic actuator coupled to the mechanical arm to move the arm between a first position and a second position;a valve in fluid communication with the hydraulic actuator for supplying fluid to the hydraulic actuator;a pump configured to discharge fluid to the valve;an engine operatively connected to the pump;a coolant system in thermal communication with the engine and including a temperature sensor; anda controller in communication with the pump and the temperature sensor,wherein the controller is configured to transmit a control signal to the pump to modify a flowrate of the pump, and wherein the controller is configured to adjust the flowrate of the pump in response to a signal from the temperature sensor that a temperature is at or above a set temperature value.2. The machine of claim 1 , wherein the controller is configured to adjust the flowrate of the pump a first amount at the set temperature and to adjust the flowrate of the pump a second amount above the set temperature.3. The machine of claim 2 , wherein the first amount is approximately 1 percent of the flowrate and the second amount is between approximately 2 percent and ...

WORK VEHICLE AND CONTROL METHOD FOR WORK VEHICLE

A work vehicle includes an engine, a traveling pump driven by the engine, a hydraulic circuit connected to the traveling pump, a traveling motor connected to the traveling pump via the hydraulic circuit, a rotational speed sensor configured to output a signal indicative of engine speed a hydraulic pressure sensor configured to output a signal indicative of hydraulic pressure of the hydraulic circuit, a controller. The controller receives the signals from the rotational speed sensor and the hydraulic pressure sensor. The controller determines whether the engine is in an over-rotation state based on engine speed. The controller determines an upper limit value of a displacement of the traveling pump based on hydraulic pressure of the hydraulic circuit. The controller limits the displacement of the traveling pump to the upper limit value or less upon determining that the engine is in the over-rotation state. 1. A work vehicle comprising:an engine;a traveling pump driven by the engine;a hydraulic circuit connected to the traveling pump;a traveling motor connected to the traveling pump via the hydraulic circuit;a rotational speed sensor configured to output a signal indicative of engine speed;a hydraulic pressure sensor configured to output a signal indicative of hydraulic pressure of the hydraulic circuit; and receive a signal from the rotational speed sensor and the hydraulic pressure sensor,', 'determine whether the engine is in an over-rotation state based on the engine speed,', 'determine an upper limit value of displacement of the traveling pump based on the hydraulic pressure of the hydraulic circuit, and', 'limit the displacement of the traveling pump to the upper limit value or less when the engine is in the over-rotation state., 'a controller configured to'}2. The work vehicle according to claim 1 , whereinthe controller is further configured to decrease the upper limit value when the engine is in the over-rotation state.3. The work vehicle according to claim 1 ...

A WORKING MACHINE ARRANGED WITH MEANS TO DRIVE AND CONTROL A HYDRAULIC PUMP

A working machine that includes an internal combustion engine, a generator, an energy storage and an electric motor for driving one or more wheels of the working machine is provided. The internal combustion engine is arranged to drive the generator and the generator is arranged to supply power to the electric motor via the energy storage. The working machine further includes an accelerator for controlling the electric motor, and a hydraulic pump for driving a hydraulic actuator. The hydraulic pump has a drive source different from the electric motor and the accelerator is arranged for controlling the speed of the hydraulic pump. 1121222324253324272827243327. A working machine () comprising an internal combustion engine () , a generator () , an energy storage () and an electric motor () for driving one or more wheels () of the working machine , the internal combustion engine being arranged to drive the generator and the generator being arranged to supply power to the electric motor via the energy storage , the working machine further comprising an accelerator () for controlling the electric motor () , and a hydraulic pump () for driving a hydraulic actuator () , characterized in that the hydraulic pump () has a drive source different from the electric motor () and the accelerator () is arranged for controlling the speed of the hydraulic pump ().22721332721. A working machine according to claim 1 , characterized in that the drive source of the hydraulic pump () is the internal combustion engine () and the accelerator () is arranged for controlling the speed of the hydraulic pump () by controlling the speed of the internal combustion engine ().33627332736. A working machine according to claim 1 , characterized in that the working machine comprises a further electric motor () and the drive source of the hydraulic pump () is said further electric motor claim 1 , and the accelerator () is arranged for controlling the speed of the hydraulic pump () by controlling the speed ...

Shovel and method of controlling shovel

A shovel includes a lower-part traveling body, an upper-part turning body mounted on the lower-part traveling body, a hydraulic actuator mounted on the upper-part turning body, an internal combustion engine disposed in the upper-part turning body, provided with a supercharger, and configured to be controlled at a constant rotational speed, a hydraulic pump connected to the internal combustion engine, and a controller configured to control horsepower absorbed by the hydraulic pump. The controller is configured to increase a load on the internal combustion engine with the hydraulic pump before a load on the hydraulic actuator increases.

HYDRAULIC DRIVE SYSTEM OF CONSTRUCTION MACHINE

Pump controller: when operation device receives neither first or second operation, outputs standby rotation speed as command rotation speed to engine controller, standby rotation speed being lower than selected reference rotation speed; when operation device receives first operation, changes command rotation speed from standby rotation speed to first target rotation speed in such a manner that as an amount of first operation increases, increasing rate of command rotation speed decreases gradually; when operation device receives second operation, changes command rotation speed from standby rotation speed to second target rotation speed in such a manner that as an amount of second operation increases, increasing rate of command rotation speed increases gradually; and feeds command current to a solenoid proportional valve that outputs secondary pressure to regulator that adjusts tilting angle of a pump, such that a discharge flow rate of the pump is proportional to amount of first and second operation. 1. A hydraulic drive system of a construction machine , the hydraulic drive system comprising:an operation device that receives a first operation for moving an actuator in a first direction and receives a second operation for moving the actuator in a second direction, in which a load on the actuator is lower than the load on the actuator moved in the first direction;a variable displacement pump that supplies hydraulic oil to the actuator and that is driven by an engine;a solenoid proportional valve that outputs a secondary pressure corresponding to a command current;a regulator that adjusts a tilting angle of the pump in accordance with the secondary pressure outputted from the solenoid proportional valve;an engine controller that controls a fuel injector of the engine;a rotation speed selector that receives a selection of a reference rotation speed of the engine; anda pump controller that outputs a command rotation speed to the engine controller and feeds the command ...

HYDRAULIC SYSTEM OF CONSTRUCTION MACHINE

A hydraulic system according to one aspect of the present disclosure includes: control valves interposed between a main pump and hydraulic actuators; and solenoid proportional valves connected to pilot ports of the control valves. Among the solenoid proportional valves, a first solenoid proportional valve and a second solenoid proportional valve are connected to a pair of pilot ports of a particular control valve, respectively. The first solenoid proportional valve and the second solenoid proportional valve are directly connected to an auxiliary pump. The solenoid proportional valves except the first solenoid proportional valve and the second solenoid proportional valve are connected to the auxiliary pump via a switching valve. The switching valve includes a pilot port that is connected, by a switching pilot line, to a first pilot line between the first solenoid proportional valve and the particular control valve. 1. A hydraulic system of a construction machine , comprising:control valves interposed between a main pump and hydraulic actuators, each control valve including a pair of pilot ports;solenoid proportional valves connected to the pair of pilot ports of the control valves;operation devices to move the control valves, each operation device outputting an electrical signal corresponding to an operating amount of the operation device; anda controller that controls the solenoid proportional valves based on the electrical signals outputted from the operation devices, whereinthe control valves include a particular control valve, and the solenoid proportional valves include a first solenoid proportional valve and a second solenoid proportional valve that are connected to the pair of pilot ports of the particular control valve by a first pilot line and a second pilot line, respectively,the first solenoid proportional valve and the second solenoid proportional valve are directly connected to an auxiliary pump,the solenoid proportional valves except the first solenoid ...

Construction machine

There is provided a construction machine that achieves both safety and operability by lowering the possibility of an accident due to contact between the construction machine and a worker in the periphery of a vehicle body while securing operability in situations where an object required for work is present in the periphery. A controller has a normal mode as a control mode for making the operation limiting control effective and a temporary cancelation mode as a control mode for temporarily canceling the operation limiting control. The controller shifts to the temporary cancelation mode in response to operation of the control canceling device while in the normal mode. The controller shifts back to the normal mode in a case where a predetermined condition not responsive to operation of the control canceling device is satisfied while in the temporary cancelation mode.

Construction Machine

A construction machine is provided which includes a hydraulic closed circuit in which a single rod hydraulic cylinder is driven directly by a bidirectionally tiltable variable displacement pump and can stably speed up the contraction action of the single rod hydraulic cylinder. In the case where a contraction action of a hydraulic cylinder 10 is instructed through an operation lever 30, when a differential pressure obtained by subtracting the pressure of a cap chamber 10a from the pressure of a rod chamber 10b is equal to or lower than a first threshold value a set to a level equal to or higher than a selection setting pressure of a flushing valve 14, a controller 20 closes a rod side selector valve 12b to disable rod assist action for supplying hydraulic fluid from a second hydraulic pump 8 to the rod chamber, and when the differential pressure is higher than the first threshold value, the controller 20 opens the rod side selector valve to enable the rod assist action.

SHOVEL

A shovel includes a lower traveling body, an upper rotating body, an attachment including a boom and an arm, a controller, an engine, and a hydraulic pump that is driven by the engine and discharges hydraulic oil to drive the attachment. The controller is configured to obtain a hydraulic load applied to the attachment and calculate an engine speed command at predetermined time intervals based on the obtained hydraulic load. 1. A shovel , comprising:a lower traveling body;an upper rotating body;an attachment including a boom and an arm;a controller;an engine; anda hydraulic pump that is driven by the engine and discharges hydraulic oil to drive the attachment,wherein the controller is configured to obtain a hydraulic load applied to the attachment and calculate an engine speed command at predetermined time intervals based on the obtained hydraulic load.2. The shovel as claimed in claim 1 , wherein the controller increases the engine speed command as the hydraulic load increases.3. The shovel as claimed in claim 1 , wherein the controller calculates the engine speed command such that the engine speed command reaches a maximal value at substantially a same time as the hydraulic load reaches a maximum value.4. The shovel as claimed in claim 1 , wherein the controller calculates the engine speed command such that the engine speed command reaches a maximal value at a time earlier than a time at which an actual engine speed reaches a minimal value.5. The shovel as claimed in claim 1 , wherein the controller calculates the engine speed command based on a decrease in an engine speed predicted based on the hydraulic load.6. The shovel as claimed in claim 1 , wherein the controller estimates the hydraulic load by using a model of the hydraulic pump.7. The shovel as claimed in claim 1 , wherein the controller estimates the hydraulic load based on a value detected by a swash-plate angle sensor.8. The shovel as claimed in claim 1 , wherein the controller estimates the hydraulic ...

HYDRAULIC CONTROL SYSTEM

To improve operability and work efficiency while achieving reduction of the number of parts and simplification of circuit structure, in a hydraulic control system equipped with hydraulic actuators whose hydraulic power sources are both the first, second hydraulic pumps. The hydraulic control system is provided with the stick directional switching valve; the main-side, sub-side supply oil passages connecting the hydraulic pumps to the stick directional switching valve; and the stick flow rate control valve which is placed in the sub-side supply oil passage, and controls the supply flow rate from the hydraulic pump when the supply flow rate to the stick cylinder requires the supply flow rates from both the hydraulic pumps, wherein the stick directional switching valve is configured such that the discharge flow rate control is performed in the entire area of the spool stroke, and the supply flow rate control is performed at the first region of the former half of the spool stroke, but not performed at the second region of the latter half of the spool stroke. 1. A hydraulic control system equipped with first , second hydraulic pumps; a first hydraulic actuator whose hydraulic supply source is both the first , second hydraulic pumps; and other hydraulic actuators whose hydraulic supply sources are at least one of the first , second hydraulic pumps , the hydraulic control system further comprising:a first hydraulic actuator directional switching valve that has a supply valve passage and a discharge valve passage to and from the first hydraulic actuator and switches between supply and discharge directions;a main-side supply oil passage, a sub-side supply oil passage that connects the first, second hydraulic pumps to pump ports of the first hydraulic actuator directional switching valve, respectively;a first hydraulic actuator flow rate control valve that is placed at the sub-side supply oil passage, and controls a supply flow rate from the second hydraulic pump to the first ...

WORKING MACHINE

A determination portion determines whether a working device is at a receivable posture which allows a receiving device to receive a radio signal transmitted from a transmission device or the working device is at an unreceivable posture which does not allow the receiving device to receive the radio signal transmitted from the transmission device based on posture information detected by a posture sensor. Then, when determining that the working device is at the unreceivable posture, the determination portion sets the receiving device in a power saving mode. On the other hand, when determining that the working device takes the receivable posture with the receiving device being set in the power saving mode, the determination portion returns the receiving device to a normal power mode. 1. A working machine comprising:a main body portion;a working device mounted on the main body portion so as to have a changeable posture, the working device including one or a plurality of replaceable replacement portions;a posture sensor which detects a posture of the working device;one or a plurality of transmission devices disposed in the replacement portions for transmitting a radio signal including identification information of the replacement portions;a receiving device disposed in the main body portion for receiving a radio signal transmitted from the transmission devices; anda determination portion which determines whether the working device is at a receivable posture which allows the receiving device to receive the radio signal or the working device is at an unreceivable posture which does not allow the receiving device to receive the radio signal based on posture information detected by the posture sensor, whereinwhen determining that the working device is at the unreceivable posture, the determination portion sets the receiving device in a power saving mode in which the radio signal is unreceivable, and when determining that the working device takes the receivable posture with ...

WORKING MACHINE

Provided is a working machine having an expanded range of a working device posture which permits information on an attachment of the working device to be transmitted from the attachment to a machine body through wireless communication. The working machine includes: a transmitter disposed in the attachment so as to be displaced together with the attachment relatively to the machine body and configured to send an information signal containing information on the attachment; a receiver disposed in the machine body and configured to receive the information signal; a controller which acquires information on the attachment based on the information signal received by the receiver; and a relay device disposed in the working device main body to receive the information signal sent by the transmitter and transmit the information signal to a position at which the information signal can be received by the receiver. 1. A working machine comprising:a machine body;a working device which includes a working device main body mounted on the machine body and an attachment detachable from the working device main body, the working device being operable to displace the attachment relatively to the machine body;a transmitter disposed in the attachment so as to be displaced together with the attachment relatively to the machine body and configured to send an information signal containing information on the attachment;a receiver disposed in the machine body and being capable of receiving the information signal;a controller which acquires information on the attachment based on the information signal received by the receiver; anda relay device disposed in the working device main body to receive the information signal sent by the transmitter and to transmit the information signal to a position at which the information signal can be received by the receiver.2. The working machine according to claim 1 , wherein the relay device includes at least one relay unit claim 1 , the at least one relay unit ...

Control System For Auxiliary Power Source

A control system includes a variable displacement hydraulic pump, the pump having an inlet for receiving fluid, an outlet for discharging fluid under pressure, and a pump displacement input, a hydraulic motor having an inlet and an outlet, a fluid circuit including a supply conduit for conducting fluid discharged by the pump to the motor and a return conduit for returning fluid discharged by the motor to the pump, a pump displacement control cooperating with the pump displacement input in order to vary a displacement of the pump, a control circuit in communication with the pump displacement control for controlling the pump output such that the motor is driven at a constant rotational speed, and a system controller in communication with the control circuit and a remote location to transmit and receive information to and from the remote location.

WORK VEHICLE AND CONTROL METHOD FOR WORK VEHICLE

A controller determines a compensation factor from an operating amount of an accelerator operating member and a hydraulic pressure of at least one of a first circuit and a second circuit. The controller determines a target vehicle speed from the operating amount of the accelerator operating member. The controller determines at least one of a target displacement of a travel pump and a target displacement of a travel motor from the target vehicle speed and the compensation factor. 1. A work vehicle comprising:an engine; a travel pump configured to be driven by the engine, the travel pump including a first pump port and a second pump port,', 'a travel motor including a first motor port and a second motor port, and', a first circuit connecting the first pump port and the first motor port, and', 'a second circuit connecting the second pump port and the second motor port;, 'a hydraulic circuit connecting the travel pump and the travel motor, the hydraulic circuit including'}], 'a hydrostatic transmission including'}a pressure sensor configured to output a signal indicative of a hydraulic pressure in at least one of the first circuit and the second circuit;an accelerator operating member;an accelerator operating sensor configured to output a signal indicative of an operating amount of the accelerator operating member; and determine a compensation factor from the operating amount of the accelerator operating member and the hydraulic pressures in at least one of the first circuit and the second circuit,', 'determine a target vehicle speed from the operating amount of the accelerator operating member, and', 'determine at least one of a target displacement of the travel pump and a target displacement of the travel motor from the target vehicle speed and the compensation factor., 'a controller configured to receive signals from the pressure sensor and the accelerator operating sensor, the controller being configured to'}2. The work vehicle according to claim 1 , wherein a first ...

SHOVEL

A shovel includes an operating element and circuitry. The circuitry is configured to recognize a worker in an area surrounding the shovel and recognize a predetermined gesture made by the recognized worker. The circuitry is further configured to perform operation control on the operating element in response to the predetermined gesture made by the worker recognized by the recognition part. 1. A shovel comprising:an operating element; andcircuitry configured to recognize a worker in an area surrounding the shovel and recognize a predetermined gesture made by the recognized worker, and to perform operation control on the operating element in response to the predetermined gesture made by the worker recognized by the recognition part.2. The shovel as claimed in claim 1 , wherein the circuitry is further configured to store correspondence information showing correspondence between the predetermined gesture and operation details of the operating element with respect to each of a plurality of predetermined gestures.3. The shovel as claimed in claim 2 , wherein the circuitry is further configured to select operation details corresponding to details of the predetermined gesture made by the worker recognized by the recognition part from the correspondence information and cause the operating element to execute the selected operation details.4. The shovel as claimed in claim 1 , wherein the circuitry is further configured to start the operation control on the operating element in response to the predetermined gesture recognized by the recognition part and cancel the operation control in response to passage of a predetermined time thereafter.5. The shovel as claimed in claim 1 , whereinthe predetermined gesture includes a cancel gesture for canceling the operation control, andthe circuitry is further configured to, after starting the operation control in response to the predetermined gesture made by a first worker recognized by the recognition part, cancel the operation control ...

HYDRAULIC SYSTEM HAVING DIAGNOSTIC MODE OF OPERATION

A hydraulic system is disclosed for use with. a machine. The hydraulic system may have an actuator, a valve associated with the actuator, at least one sensor configured to generate signals indicative of performance parameters of the hydraulic system, and a controller. The controller may be configured to determine at least one of a diagnostic movement and position of at least one of the fluid actuator and valve required to perform a health cheek, and to correlate the signals generated only during completion of the diagnostic movement or only when the at least one of the fluid actuator and valve are in the diagnostic position to values of the performance parameters. The controller may also be configured to make a comparison of the values of the performance parameters to expected values, and to determine a health of the hydraulic system based on the comparison. 1. A hydraulic system , comprising:a fluid actuator;a valve associated with the fluid actuator;at least one sensor configured to generate a signal indicative of a performance parameter of the hydraulic system; and determine at least one of a diagnostic movement and a diagnostic position of at least one of the fluid actuator and the valve required to perform a health check of the hydraulic system;', 'correlate the signal generated only during completion of the diagnostic movement or only when the at least one of the fluid actuator and the valve are in the diagnostic position to a value of the performance parameter;', 'make a comparison of the value of the performance parameter to an expected value; and', 'determine a health of the hydraulic system based on the comparison., 'a controller in communication with the at least one sensor and configured to2. The hydraulic system of claim 1 , wherein the at least one sensor is one of a pressure sensor claim 1 , a position sensor claim 1 , a displacement sensor claim 1 , and a speed sensor.3. The hydraulic system of claim 1 , wherein the at least one sensor includes at ...

Construction Machine

Provided is a construction machine which can promptly adjust the rotational speed of a swing motor to a target rotational speed. A controller calculates a target rotational speed of the swing motor based on input from an operation device, calculates a degree of deviation of a rotational speed detected by a rotational speed sensor from the target rotational speed, sets a target driving pressure of the swing motor according to a moment of inertia about a swing axis of a swing structure and a work device and controls a pressure adjusting device in such a manner as to reduce a difference between a driving pressure detected by a pressure sensor and the target driving pressure, when the degree of deviation is larger than a predetermined value, and controls the pressure adjusting device in such a manner as to reduce a difference between the rotational speed detected by the rotational speed sensor and the target rotational speed, when the degree of deviation is equal to or smaller than the predetermined value. 1. A construction machine comprising:a track structure;a swing structure swingably attached onto the track structure;a work device attached to the swing structure;a hydraulic operating fluid tank;a hydraulic pump that delivers hydraulic operating fluid sucked from the hydraulic operating fluid tank;a swing motor that is supplied with the hydraulic operating fluid from the hydraulic pump and drives the swing structure; andan operation device for giving an instruction for operation of the swing structure, wherein a rotational speed sensor that detects a rotational speed of the swing motor,', 'a pressure sensor that detects a driving pressure of the swing motor,', 'a pressure adjusting device capable of adjusting the driving pressure of the swing motor, and', 'a controller that controls the pressure adjusting device, and, 'the construction machine comprises'} calculate a target rotational speed of the swing motor based on input from the operation device,', 'calculate a ...

Hydraulic System

A hydraulic system for a working vehicle, the hydraulic system includes a hydraulically actuated device; a hydraulic pump assembly for supplying a variable output of hydraulic fluid to the hydraulically actuated device; and a proportional control valve, wherein the hydraulic system is arranged such that hydraulic fluid exiting the hydraulically actuated device flows through a restriction of the proportional control valve; and wherein the hydraulic system is configured to control a flow of hydraulic fluid supplied to the hydraulically actuated device by varying the output of hydraulic fluid from the hydraulic pump assembly, and to control a flow of hydraulic fluid exiting the hydraulically actuated device via adjusting a restriction area of the proportional control valve. 1. A hydraulic system for a working vehicle , the hydraulic system comprising:a hydraulically actuated device;a hydraulic pump assembly for supplying a variable output of hydraulic fluid to the hydraulically actuated device; anda proportional control valve, wherein the hydraulic system is arranged such that hydraulic fluid exiting the hydraulically actuated device flows through a restriction of the proportional control valve; andwherein the hydraulic system is configured to control a flow of hydraulic fluid supplied to the hydraulically actuated device by varying the output of hydraulic fluid from the hydraulic pump assembly, and to control a flow of hydraulic fluid exiting the hydraulically actuated device via adjusting a restriction area of the proportional control valve.2. A hydraulic system according to claim 1 , wherein the hydraulic system is configured so that restriction of the proportional control valve is controlled independently to the output from the hydraulic pump assembly such that pressure of an inlet side of the hydraulically actuated device is controlled independently of the pressure of an outlet side of the hydraulically actuated device.3. A hydraulic system according to claim 1 , ...

Work Machine Management System

It is made possible to prevent damage to hydraulic parts of a work machine due to a decrease in performance of a hydraulic fluid even when the hydraulic fluid of a hydraulic system is changed and the hydraulic fluid becomes a mixed oil in which a mineral oil and a biodegradable oil are mixed with each other. For this purpose, a storage device stores, in advance, oil change history information of the hydraulic fluid, oil kind determination values for determining whether the hydraulic fluid is either the mineral oil or the biodegradable oil or the mixed oil of the mineral oil and the biodegradable oil, and abnormality determination values for respective kinds of the hydraulic fluid. A controller checks whether the oil change history information includes oil change information for which oil kind determination has not been made. When there is oil change information for which oil kind determination has not been made, the controller determines a kind of the hydraulic fluid on the basis of the respective values of a plurality of oil properties detected by an oil sensor and the oil kind determination values. The controller determines an abnormality in the hydraulic fluid by using abnormality determination values corresponding to a result of determination of the kind of the hydraulic fluid.

Construction Machine

A construction machine is provided which is capable of detecting an operation state of an operation device even if the idle rotation speed for a prime mover is set to a low value and is capable of setting the idle rotation speed for the prime mover to a low value. A hydraulic excavator includes an operation device that generates a pilot pressure corresponding to an operation amount of an operation lever and switches a control valve with the generated pilot valve, and a controller that controls an electric motor such that the rotation speed of the electric motor becomes an idle rotation speed set in advance when a no-operation state of the operation device continues. The hydraulic excavator further includes a hydraulic pressure signal line that is connected between the discharge side of a pilot pump and a tank and in which the control valve is interposed, a fixed restrictor provided between the discharge side of the pilot pump and the control valve in the hydraulic pressure signal line, and pressure sensors that individually detect the hydraulic pressures on the upstream side and the downstream side of the fixed restrictor. The controller detects an operation state of the operation device on the basis of results of detection of the pressure sensors. 1. A construction machine that includes a prime mover , a hydraulic pump driven by the prime mover , a hydraulic actuator , a control valve that controls flow of hydraulic fluid from the hydraulic pump to the hydraulic actuator , an operation device that generates a pilot pressure corresponding to an operation amount of an operation lever and switches the control valve with the generated pilot pressure , and a controller that controls , when a no-operation state of the operation device continues , a rotation speed of the prime mover to an idle rotation speed set in advance , the construction machine comprising:a pilot pump that is driven by the prime mover and whose discharge pressure is used as a source pressure of the ...

Work machine having an attachment device, in particular a trench cutter, and attachment device, in particular a trench cutter

The present invention relates to a work machine, preferably a mobile work machine, having an attachment device, in particular a trench cutter, wherein the attachment device comprises at least two adjustable hydraulic motors for driving independent, individually controllable loads, and wherein the hydraulic supply of the adjustable hydraulic motors takes place by a hydraulic drive unit arranged externally from the attachment device, in particular by a drive unit of the work machine, and wherein the at least two adjustable hydraulic motors of the attachment device are connected to a constant pressure network provided by the hydraulic drive unit. 1. A work machine , preferably a mobile work machine , having an attachment device , in particular a trench cutter , wherein the attachment device comprises at least two adjustable hydraulic motors for driving independent , individually controllable loads , the hydraulic supply of the adjustable hydraulic motors takes place by a hydraulic drive unit arranged external to the attachment device , in particular by a drive unit of the work machine , andthe at least two adjustable hydraulic motors of the attachment device are connected to a constant pressure network provided by the hydraulic drive unit.2. A work machine in accordance with claim 1 , wherein the at least two adjustable hydraulic motors are reversible.3. A work machine in accordance with claim 1 , wherein the at least two adjustable hydraulic motors are secondarily regulated by a control and the displacement volume of the motor is changed for so long until an equilibrium of the motor torque with the respective load at the motor is present and the desired speed and/or a defined time progression of the drive power and/or a desired drive torque is/are reached.4. A work machine in accordance with claim 3 , wherein a sensor system is provided for detecting the speed and/or the adjustment angle of the individual hydraulic motors and/or operating pressures in the high ...

Hydraulic Power Control Circuit and Construction Vehicle Comprising Such Circuit

In a load sensing hydraulic control circuit, a pressure compensator elaborates both a load sensing pressure signal to control a pump unit and a pressure compensated power flow for actuators, the power flow being either split or alternatively directed to at least a first and a second actuator control valves so that a differential pressure across the first and second control valves is controlled by the pressure compensator. In one embodiment, the circuit is onboard a construction vehicle to power actuators such is travel left, travel right, swing, boom, arm, bucket and the like. 1. A hydraulic control circuit comprising:a first actuator line for feeding a first hydraulic actuator;a second actuator line for feeding a second hydraulic actuator;a pump line connectable to a pump unit and providing power flow for actuation of the first and second actuators;a tank return line connectable to an hydraulic fluid sump;a first control valve for controlling the flow to the first hydraulic actuator;a second control valve for controlling the flow to the second hydraulic actuator;a load sensing line connectable to the pump unit in order to control the flow delivered by the pump unit to the pump line; a compensator input to receive flow directed to the first and/or second actuator lines; and', 'a first output connected to a T-branched or a multi T-branched compensator output line having an output node in which flow is either split to the first and second control valves or directed to the first control valve or the second control valve to power the first and second actuator lines through the first and second control valves;, 'a single pressure compensator for controlling differential pressure across the first and second control valves and havinga second output connected to the load sensing line; anda T-branched or multi T-branched input line having an input node merging flow from a first line and a second line connected to the first and second control valves respectively to provide a ...

DEVICE FOR CONTROLLING CONTROL VALVE OF CONSTRUCTION MACHINE, METHOD FOR CONTROLLING SAME, AND METHOD FOR CONTROLLING DISCHARGE FLOW RATE OF HYDRAULIC PUMP

An apparatus and method for controlling a control valve, and a method for controlling a discharge flow rate of a hydraulic pump for a construction machine are disclosed, which can control a spool shifting speed of a directional valve and a discharge flow rate of a hydraulic pump in accordance with a hydraulic fluid temperature in winter season with below zero temperatures. The apparatus for controlling a control valve includes a variable displacement hydraulic pump; a hydraulic actuator driven by hydraulic fluid that is supplied from the hydraulic pump; a control valve installed in a flow path between the hydraulic pump and the hydraulic actuator and shifted to control a start, stop, and direction change of the hydraulic actuator; an operation lever outputting an operation signal corresponding to an operation amount; a temperature sensor detecting a hydraulic fluid temperature of a hydraulic fluid tank connected to the hydraulic pump; and a controller applying a control signal that corresponds to the operation amount of the operation lever to the control valve if the hydraulic fluid temperature detected through a signal from the temperature sensor is higher than a predetermined temperature, and adjusting the operation signal according to the operation amount of the operation lever in a predetermined increment rate to correspond to the detected hydraulic fluid temperature and applying the adjusted control signal to the control valve if the hydraulic fluid temperature detected through the signal from the temperature sensor is lower than the predetermined temperature. 1. An apparatus for controlling a control valve for a construction machine comprising:a variable displacement hydraulic pump;a hydraulic actuator driven by hydraulic fluid that is supplied from the hydraulic pump;a control valve installed in a flow path between the hydraulic pump and the hydraulic actuator and shifted to control a start, stop, and direction change of the hydraulic actuator;an operation ...

WORKING VEHICLE AND CONTROL METHOD THEREFOR

A transmission requirement setting unit sets a required traction force in a work vehicle on the basis of an accelerator operation amount. A work implement requirement setting unit sets a required flow rate on the basis of a work implement operation amount. An engine requirement setting unit determines the horsepower required from the engine on the basis of the horsepower required by the transmission set on the basis of the required traction force, and the horsepower required by the work implement set on the basis of the required flow rate. A required throttle setting unit determines a commanded throttle value sent to the engine on the basis of the horsepower required from the engine. A pump displacement setting unit sets a target displacement for the hydraulic pump on the basis of the required flow rate. The work implement requirement setting unit sets an upper limit for the required flow rate to a prescribed flow rate limit value when the discharge pressure of the hydraulic pump is at or above a prescribed pressure threshold. 1. A work vehicle comprising:an engine;a variable displacement hydraulic pump driven by the engine;a work implement driven by hydraulic fluid discharged from the hydraulic pump;a pump displacement control device for controlling the displacement of the hydraulic pump;a pump pressure detector for detecting a discharge pressure from the hydraulic pump;a relief valve which opens when the discharge pressure from the hydraulic pump reaches or exceeds a prescribed relief pressure;a travel device allowing the vehicle to travel;a power transmission device into which drive power from the engine enters so that the power transmission device outputs the drive power for driving the travel device;an accelerator operation member;a work implement operation member; anda controller for controlling the power transmission device; a transmission requirement setting unit for setting a required traction force that is a target traction force for the travel device on ...

ELECTRO-HYDRAULIC FEED DELIVERY SYSTEM

A hydraulic system for a feed delivery unit according to the present disclosure may include a pump configured to supply a total flow, the pump including at least one suction port configured to be connected to a reservoir and at least one outlet port configured to be connected to a supply line, a control valve fluidly coupled to the pump and including a plurality of valve sections, the control valve being coupled to the pump such that the total flow supplied by the pump is distributed among the plurality of valve sections, and wherein each valve section of the plurality of valve sections is configured to control a direction of flow of a portion of the total flow, and a plurality of hydraulic motors fluidly coupled to the pump via the control valve, each of the motors being configured to drive a respective auger of the feed delivery unit. 1. A hydraulic system for a feed delivery unit , the system comprising:a pump configured to supply a total flow, wherein the pump includes at least one suction port configured to be connected to a reservoir and at least one outlet port configured to be connected to a supply line;a control valve fluidly coupled to the pump and comprising a plurality of valve sections, wherein control valve is coupled to the pump such that the total flow supplied by the pump is distributed among the plurality of valve sections, and wherein each valve section of the plurality of valve sections is configured to control a direction of flow of a portion of the total flow; anda plurality of hydraulic motors fluidly coupled to the pump via the control valve, each of the motors configured to drive a respective auger of the feed delivery unit.2. The hydraulic system of claim 1 , wherein the plurality of valve sections includes a first valve section configured to direct hydraulic fluid to and from a first hydraulic motor configured to drive a floor auger of the feed delivery unit claim 1 , a second valve section configured to direct hydraulic fluid to and from ...

Divided Pump Implement Valve and System

A hydraulic system and method of controlling such on a machine is disclosed. The hydraulic system may comprise a primary hydraulic circuit that includes a first load sense controlled pump, a secondary hydraulic circuit that includes a second load sense controlled pump, a flow sharing valve, and a load sense arrangement. The load sense arrangement may include a main resolver configured to select a higher pressure signal between the primary and secondary hydraulic circuits, and a load sense valve having an open position at which pressure signal flow between the primary hydraulic circuit and the main resolver is allowed, and a closed position at which pressure signal flow between the primary hydraulic circuit and the main resolver is blocked. In an embodiment, when the load sense valve is in the closed position, the second load sense controlled pump may be controlled only by the secondary hydraulic circuit. 1. A hydraulic system on a machine , the machine including a first implement , the hydraulic system comprising:a primary hydraulic circuit that includes a first load sense controlled pump;a secondary hydraulic circuit that includes a second load sense controlled pump;a flow sharing valve disposed between the primary and secondary hydraulic circuits; and a main resolver configured to select a higher pressure signal between the primary and secondary hydraulic circuits; and', 'a load sense valve having an open position at which pressure signal flow between the primary hydraulic circuit and the main resolver is allowed, and a closed position at which pressure signal flow between the primary hydraulic circuit and the main resolver is blocked, wherein when the load sense valve is in the closed position, the second load sense controlled pump is controlled only by the secondary hydraulic circuit., 'a load sense arrangement for the second load sense controlled pump, the load sense arrangement including2. The hydraulic system of claim 1 , wherein the load sense valve is in ...