Multifunctional single-cylinder engine testing device

A multifunctional single-cylinder engine testing device disclosed by the present invention comprises a single-cylinder engine body, the single-cylinder engine body comprises a crankcase, a crankshaft, a middle water jacket, a cylinder head, a cylinder head cover, an oil pan, a camshaft, a piston, a connecting rod and a cylinder sleeve, the cylinder sleeve is installed in the middle water jacket, and the middle water jacket is detachably installed at the top end of the crankcase. The cylinder cover is arranged at the top end of the middle water jacket, the cylinder cover is arranged at the top end of the cylinder cover in a covering mode, the cam shaft is installed in the cylinder cover, the piston is in transmission connection with the crankshaft through a connecting rod, the crankshaft is installed in the crankcase in a rotating mode, and the piston is in sliding connection with the cylinder sleeve in the middle water jacket. The invention discloses a multifunctional single-cylinder engine ...

Electrolytic tank with electrolyte distribution and convergence structure

The invention discloses an electrolytic bath with an electrolyte distribution and confluence structure, which comprises an electrolytic bath body, support legs are mounted on the electrolytic bath body, a confluence pipe is communicated in the electrolytic bath body, and a negative electrode plate and a positive electrode plate are respectively mounted at two ends in the electrolytic bath body. According to the electrolytic bath with the electrolyte distribution and confluence structure, the air drying assembly and the cleaning assembly are arranged, so that after the electrolytic bath body finishes electrolysis of water, the air drying assembly can be used for drying the water, and the air drying assembly can be used for cleaning the water; the shunting electrode plate, the positive electrode plate and the negative electrode plate are air-dried under the action of the air-drying assembly, and then the shunting electrode plate, the positive electrode plate and the negative electrode plate ...

Beneficiation method for comprehensively improving indexes of low-grade lepidolite concentrate

The invention provides a beneficiation method for comprehensively improving indexes of low-grade lepidolite concentrate, and relates to the field of beneficiation. The beneficiation method comprises the steps that low-grade lepidolite ore is ground through a rod mill to obtain ore pulp, then a pH regulator and a collecting agent are added for multiple times of roughing, and rough concentrate and roughing tailings are obtained; the rough concentrate is screened and classified, oversize products are high-grade lithium concentrate, and undersize products are subjected to multiple times of concentration to obtain lithium concentrate; and a collecting agent is added into the roughing tailings for multiple times of scavenging, scavenged concentrate returns to the ore pulp or is scavenged in the last stage, and scavenged tailings serve as final tailings to be treated. According to the beneficiation method provided by the invention, the lepidolite is subjected to flotation recovery under the condition ...

Processing method for red alga polysaccharide

The invention relates to the technical field of sea chemical engineering, and especially relates to a processing method for red alga polysaccharide. According to the processing method, washing, alkali processing, water washing, pretreating, enzymolysis, extraction, plate filtration, potassium processing, press filtration, dehydration, crushing, drying and other technological steps are employed, and traditional technological steps are reduced, so that the production period of red alga polysaccharide is shortened, the problems are reduced that red alga production is high in water consumption, high in energy consumption and more in usage amount of raw materials and auxiliary materials, and also the extraction yield of red alga polysaccharide is improved by 2-3% compared with the extraction yield of a conventional preparation technology.

Method for preparing sodium alginate from kelp

The invention relates to a method for preparing sodium alginate from kelp, which adopts kelp as a raw material. The preparation process of the method comprises raw-material pretreatment, digestion, calcification, decalcification, dehydration, neutralization, drying, blending and milled-powder packaging, wherein flocculant is adopted for foamed floating during digestion. As the kelp is one of plants growing fastest in the world, the kelp can be cultured on a large scale in continental-shelf sea areas, and leaves of ripe kelp concentrating on the surface of seawater are beneficial to harvesting, so that production cost is reduced. The method also adopts the flocculant for foamed floating, thereby having the advantages of shortening floating time and improving product quality.

Observation structure of heat exchanger anticorrosion spelter

The utility model discloses an observation structure of heat exchanger anticorrosion spelter. This observation structure includes: casing, its material adopt the iron material, and the both ends of this casing are closed through intake end cover and play water end (W. E. ) cap seal respectively, the cooler core, it sets up in the inside of this casing, and this cooler core adopts copper tubulose material, the zinc bar lid, it is adorned soon on the intake end cover of casing, the axial of this zinc bar lid has been seted up the zinc bar internal thread and has been observed the hole, and the zinc bar, its one end spiro union arrives in the zinc bar internal thread of zinc bar lid, the other end of this zinc bar stretches into in the casing. This observation structure of heat exchanger anticorrosion spelter offers at zinc bar lid and observes the hole, can observe inside zinc bar by the corruption circumstances through the inside liquid of this observations hole seepage, need not tear open ...

Low-viscosity sodium alginate for soft capsules as well as preparation method and application of low-viscosity sodium alginate

The invention discloses low-viscosity sodium alginate for soft capsules as well as a preparation method and application of the low-viscosity sodium alginate. The preparation method comprises the following steps: by taking common sodium alginate as a raw material, dissolving, carrying out enzymolysis by utilizing hemicellulase, carrying out alcohol precipitation, drying and crushing to obtain low-viscosity sodium alginate, and further carrying out microwave treatment on the basis to obtain the ultralow-viscosity sodium alginate. According to the invention, two kinds of low-viscosity sodium alginate and common sodium alginate are compounded as a seaweed-based capsule material for dripping enteric soft capsules. The enteric soft capsule can be used for wrapping various contents, the soft capsule material has enteric solubility and low temperature in the whole dripping process, so that the soft capsule is particularly suitable for preparing probiotic soft capsules, and the method has the advantages ...

Extracting and processing technology of food additive G-type alginate

The invention relates to a extracting and processing technology of food additive G-type alginate, which comprises the following steps. Brown algae are subjected to swelling, enzymatic hydrolysis, digestion, dilution, foaming, floating and fine filtration. KCl solution is added in the above fine filtrate. M segment of alginate is deposited and filtered. Then glue solution of M segment and G segment with the content ratio of 0.5-0.8 is obtained. The above glue solution is subjected to calcification, decalcification, dehydration, neutralized conversion, granulation and drying to obtain G-type alginate. The cell wall of brown algae is subjected to swelling to make the brown algae much easier to be completely converted. The cell wall of brown algae is also subjected to enzymatic hydrolysis to improve the quality and recovery rate of alginate. Sylvite is added to deposit M segment and increase the content of G segment in products. The above technology has the advantages of better product performance ...

Underwater rapid-decoupling type lifting frame for releasing cement briquettes

The invention discloses an underwater rapid-decoupling type lifting frame for releasing cement briquettes. The lifting frame provided by the invention comprises a frame main body (1), wherein the frame main body (1) is connected with a tie rod unit (2) into a whole through multiple guiding units (172) arranged in the middle of the frame main body (1); and the tie rod unit (2) is provided with a control device (4) used for driving the tie rod unit (2) to slide. The underwater rapid-decoupling type lifting frame in the invention is simple in structure, easy to operate and free of water depth limitation, and can be used for realizing underwater safe operation for divers, achieving cement briquette installation through a robot under an unmanned deepwater condition, lowering the construction cost on the sea and improving the working efficiency.

Method for preparing sodium alginate from kelp

The invention relates to a method for preparing sodium alginate from kelp, which adopts kelp as a raw material. The preparation process of the method comprises raw-material pretreatment, digestion, calcification, decalcification, dehydration, neutralization, drying, blending and milled-powder packaging, wherein flocculant is adopted for foamed floating during digestion. As the kelp is one of plants growing fastest in the world, the kelp can be cultured on a large scale in continental-shelf sea areas, and leaves of ripe kelp concentrating on the surface of seawater are beneficial to harvesting,so that production cost is reduced. The method also adopts the flocculant for foamed floating, thereby having the advantages of shortening floating time and improving product quality.

Constant feeding adjustment device

The invention relates to a constant feeding adjustment device, which is applied to the fields of water conservancy, metallurgy, electric power, port and pier, coal, building materials, chemical engineering and the like. The constant feeding adjustment device comprises a hydraulic controllable gate stock bin, a hydraulic controllable gate valve, a variable feeding machine and a constant feeding machine, wherein the variable feeding machine is connected to the lower part of the hydraulic controllable gate stock bin; the constant feeding machine is connected to the lower part of the variable feeding machine; the variable feeding machine is arranged on the lower part of the hydraulic controllable gate stock bin; the hydraulic controllable gate stock bin is provided with the hydraulic controllable gate valve; the constant feeding machine is arranged under the variable feeding machine. The device can quickly and accurately adjust conveying material capacity, and can realize continuous automatic ...

Long time recording mode using frame alignment signal and videorecorder

The present invention relates to a long-time recording mode adopting frame alignment signal and video recorder, applicable to helical scan type anolog or digital signal video recorder. The frame alignment signal is prerecorded on the tape, and a frame interval recording mode is used to videotape so as to can prolong the tape recording time by N times. The commutation switch, preamplifier circuit,shaping circuits, bistable trigger-action circuit, tape control circuit, N frequency divider and phase averaging circuit are added in capstan servo-circuit of general video recorder, and the delay circuit, shaping circuit and magnetic head control electronic switch are added in its video head recording circuit so as to can implement said invention. Besides, the computer programme or special-purpose IC also can be used to implement said invention.

Quick copying method and system for videotape

Medium condensing equipment of evaporator

The medium condensing equipment comprises an outer frame, mounting holes are formed in the two sides of the outer frame, side plates are fixedly connected to the two ends of one side of the outer frame, heat dissipation holes are formed in one sides of the side plates, and heat dissipation fans are fixedly connected to one sides of the side plates; a limiting block is arranged at one end of the condensation pipe in a sleeving manner; the sealing box is installed at the end, away from the outer frame, of the bottom of the condensation pipe, and the sealing box communicates with the condensation pipe; and the scraping device comprises a scraping plate. According to the medium condensing equipment of the evaporator, the purpose of improving the automation degree is achieved, incrustation impurities attached to the inner wall of the condensing pipe can be automatically cleaned through the thrust of moving of a condensing medium in the equipment using process, and the situation that when the ...

Seaweed high-activity dietary fiber and production method thereof

The invention relates to a seaweed high-activity dietary fiber and a production method thereof; the dietary fiber adopts seaweed slag liquid produced in the production process of seaweed glue as raw material, filter residue and filter liquid in the seaweed slag liquid are respectively taken out, the filter liquid is activated by processing technique, so as to prepare soluble dietary fiber; meanwhile, the filter residue is processed to prepare the insoluble dietary fiber; and then the soluble dietary fiber and the insoluble dietary fiber are formulated to form the seaweed high-activity dietaryfiber. The invention adopts the residual seaweed slag liquid in the production of sodium alginate tech grade and carrageenan as raw material for producing the dietary fiber, thereby greatly reducing the production cost without decreasing the quality of the dietary fiber; in addition, the raw material is respectively prepared in the soluble dietary fiber and the insoluble dietary fiber correspondingly ...

Standardized rapid assembly construction method for tunnel secondary lining steel bars

The invention discloses a standardized rapid assembly construction method for tunnel secondary lining steel bars. The method can be realized by two technical paths: the technical path A is used for processing five-section assembled secondary lining steel bars outside a hole, and inward bending is realized through movable hinges among sections to realize overall reduction of the secondary lining steel bars; and finally, secondary lining concrete pouring is carried out through the technologies of walking of the secondary lining steel bar assembly trolley, a jacking system, forward moving of the secondary lining trolley, spatial dislocation and then back-off in place and the like. According to the technical path B, the overall height of secondary lining steel bars can be reduced by lengthening the reserved height of tunnel inverted arch steel bars, secondary lining steel bar annular sheet body machining is conducted outside a tunnel, secondary lining steel bar annular single body longitudinal ...

Extracting and processing technique of carrageen

The invention relates to an extracting and processing technique of carrageen by utilizing eucheuma, which comprises the procedures of cleaning, alkali treatment, washing, enzymatic hydrolysis, extracting, filtering, potassic alteration, dehydration, crushing and drying. By adopting enzyme biotechnology technology, the extraction rate and quality of carrageenan are improved, while the production cycle and energy consumption thereof being lowered. Colloid dissolves out of carrageen cells completely after the organization of cellulose in carrageen cell wall being destroyed during the procedure of enzymatic hydrolysis, thus improving the extraction rate of carrageenan. Meanwhile, the time of boiling procedure is shortened and the temperature thereof is lowered. The yield of products is increased and steam consumption during the process is reduced. Small molecule pigments also dissolve out of carrageen cells during the procedure of enzymatic hydrolysis, thus improving the transparency and purity ...

Method for processing high-activity seaweed dietary fibers by use of processed seaweed waste residue liquid

The invention relates to a method for processing high-activity seaweed dietary fibers by use of processed seaweed waste residue liquid. The method is characterized by comprising the following steps: carrying out centrifugal separation, acid and alkali treatment, flocculation, high-temperature cooking, enzyme hydrolysis, decoloring, deodorization, activation and superfine grinding and compounding. According to the method, the utilization rate of the seaweed waste residue liquid can be improved, the product yield is improved, the purity of the dietary fibers is improved favorably, and high activity of the product is ensured. The seaweed fiber has high extraction rate, the bioavailability of the seaweed dietary fiber is high, toxic residues cannot be generated in the product, no water flushing is required, and no environment pollution is caused. The adopted two bleaching agents have the characteristics of no harm and no residue and are environment-friendly bleaching and disinfection agents ...

Novel capacitance voltage-division type voltage transducer

The invention discloses a novel capacitance voltage-division type voltage transducer which comprises an electrode, a high voltage component, a voltage divider, a shielded wire and a casting body. The capacitance voltage-division type voltage transducer has a simple structure, and is convenient to install; a dielectric medium with a favorable temperature characteristic and a favorable voltage coefficient is used for filling the key components (voltage divider and the high voltage component) of the capacitance voltage-division type voltage transducer, the influence of temperature and electromagnetic interference on errors can be preferably overcome, and the secondary output accuracy of a product reaches level 0.2.

ANTI-COPY VIDEO TAPE RECORDING METHOD AND EQUIPMENT

The anti-copy method comprises superimposing a white level signal which is larger than the frame width and higher than the reference frame blanking level on the video signal to be recorded, and elimininating intermittently the synchronizing signal in the interval of the white level signal, and adding interference pulses which can disturb the work of AGC circuit of the VCR at appropriate position of the video signal, the recorded tape can be played normally, but its copy cannot.

High-gel-strength algin and preparation method for same

The invention discloses high-gel-strength algin, which comprises the following raw materials in percentage by mass: 55 to 60 percent of algin, 5 to 10 percent of sodium hexametaphosphate, 20 to 25 percent of calcium sulfate dihydrate and 50 to 10 percent of glucolactone. When the product forms an equal amount of gel, a small amount of algin is used, so that the using amount of the algin can be reduced, and the product is low in cost, high in gelling speed, uniform in gelling and high in toughness; the raw materials in the formula are easily available, and the product is low in heat and nontoxic; due to the addition of the glucolactone, the product is easy to swell and high in flexibility, and tastes good; the product has effects of curing, thickening, emulsification, suspension, stabilization and food dryness prevention when being added into food, and has the characteristics of high formability and easiness for shaping; a preparation method for the product is convenient and easy to operate ...

Straw for cell culture of prevent pollution

The utility model relates to a the utility model relates to a straw for cell culture of prevent pollution, the straw includes attraction part, pipe body part, press section, attraction part, pipe body part, press section are once whole shaping, attraction part is frustum shape, the press section is dumbbell shape, the last fixing device that is equipped with of pipe body part, fixing device is including card strip, sleeve, the card strip is fixed on telescopic outer wall, the card strip is horizontal portion and vertical portion, sleeve swing joint is in the pipe body part periphery. Its advantage shows: the utility model discloses a straw for cell culture of prevent pollution has the fixed action, prevents to drop, the nature controlled is good, the effect of reducing pollutants risk, reduces behind the hand contact straw pollution that may bring cell culture bottle, and better improvement experiment accuracy reduces the experiment and pollutes the loss that may cause.

Solid-liquid mixed high-temperature solution waste heat recycling and utilizing device and method

The invention discloses a solid-liquid mixed high-temperature solution waste heat recycling and utilizing device which comprises a material inlet, a first-stage flash evaporation system, a second-stage flash evaporation system, a slagging tank, an impurity pump and a material outlet, wherein the material is formed in a first-stage flash evaporation tank; the bottom of a first-stage gas-solid separator is connected with the slagging tank through a first-stage slagging pipeline; the first-stage flash evaporation tank is connected with a second-stage flash evaporation tank; the second-stage flash evaporation tank is connected with a second-stage gas-solid separator; the second-stage gas-solid separator is connected with the slagging tank through a second-stage slagging pipeline; a pipeline which is connected to one end of the impurity pump is arranged at the bottom of the second-stage flash evaporation tank; the other end of the impurity pump is connected with the material outlet. The invention ...

Transmission circuit used for Ethernet

The invention discloses a transmission circuit used for Ethernet. The transmission circuit comprises four transmission element sets; for each transmission element set, a first capacitor and a first inductor are serially connected and coupled to an Ethernet connector and an Ethernet chip through a first transmission line and a second transmission line respectively, and a second capacitor and a second inductor are serially connected and coupled to the Ethernet connector and the Ethernet chip through a third transmission line and a fourth transmission line respectively; a first element set is coupled between the first transmission line and the second transmission line, and a second element set is coupled between a first connecting point between the first capacitor and the first inductor and a second connecting point between the second capacitor and the second inductor.

Ultrasonic high-COD (Chemical Oxygen Demand) salt-containing wastewater pretreatment equipment

The invention belongs to the technical field of sewage treatment, and particularly relates to ultrasonic high-COD salt-containing wastewater pretreatment equipment which comprises a main storage barrel, a sliding filter membrane is slidably connected to the surface of the main storage barrel, water injection devices are slidably connected to the two sides of the surface of the sliding filter membrane, and a propelling device is slidably connected to one end of an inner cavity of the main storage barrel. According to the device, sewage entering an inner cavity of a main storage barrel from a water injection through pipe is filtered through an external sliding filter membrane, large-particle impurities in the sewage are removed, then the pretreatment effect is achieved, however, the problems that the sliding filter membrane needed for filtering is prone to damage in the pressurization process, and a single filter point is prone to being blocked are solved, and the problem that an existing ...

Current sensor adopting differential coil structure

The invention discloses a current sensor adopting a differential coil structure for eliminating external magnetic field interference. The current sensor comprises a primary current carrier, a primary current sensing unit, a compensating winding, a double-shielding twisted pair and an air plug. The primary current carrier passes through the center of the primary current sensing unit; and the metal shielding shell of the winding, the shielding layer of a signal transmission wire and the metal part of the air plug form a whole to improve the signal-to-noise ratio of secondary signals. The hollow coil has the key technology of improving the noise immunity of power frequency magnetic fields. By improving the internal structure of the coil, adding a loop wire in the coil, manufacturing two hollow coils with consistent structures and performance parameters and counteracting the external magnetic field interference through differential structures connected in series at the corresponding terminals ...

Continuous horizontal type strong blending machine

The invention relates to a continuous horizontal type strong blending machine, which is applied to the fields of water conservation, metallurgy, power, ports and wharfs, coal, building material, chemical engineering and the like. The machine comprises a material receiving hopper, a plow type stirring device, spiral blades, a spiral main shaft, a groove body, a material discharging hopper and a driving device, wherein the driving device is connected with the spiral main shaft, the plow type stirring device and the spiral blades are arranged on the spiral main shaft, the material receiving hopper and the material discharging hopper are connected with the groove body, the spiral blades and the plow type stirring device are welded on the spiral main shaft, the plow type stirring device consists of four groups of plow scoops, and the plow scoops are symmetrically arranged between the adjacent spiral blades. The plow type stirring device has the advantages that the defect of nonuniform blending ...

Long service time magnetic tape recording mode and video recorder therefor

The invention is suited to one yield to one track video record in spiral scanning mode. It can extend tape record time to N times and record image in interval field recroding mode that record one field singnal inter the period of every adjacent N video fields. The tape can be run continuously or interruptedly. It can be realized by increasing N frequency multiplier 2 to capstan servo circuit, video head recording-switching circuits 11, 12, 13, 14 t video head recording circuit, difrequency divider 20 to control singnal circuit in common recorder or utilizing computer program or special IC. This invention is especiallly suited for long duration monitoring record. Advantages are: short sample interval time, without leakage of record, clear replay image, low cost.

Welding-free self-locking precise guiding tunnel feet-lock anchor pipe/rod construction device

The invention discloses a welding-free self-locking precise guiding tunnel feet-lock anchor pipe/rod construction device which comprises two half connecting pieces, and when the welding-free self-locking precise guiding tunnel feet-lock anchor pipe/rod construction device is used, the two half connecting pieces are fixed together through high-strength bolts; each half connecting piece comprises a front guide plate, the inner side wall of the front guide plate is fixedly connected with the inner side wall of the rear guide plate through an inclined connecting plate, the front guide plate and the rear guide plate are each provided with a guide hole, and a limiting plate is arranged at the position, close to the front guide plate, of the inclined connecting plate; the two wedge-shaped blocks are fixed to the surface of a front flange plate of the profile steel arch frame at intervals, the sharp ends of the wedge-shaped blocks are oppositely arranged, and after the two half connecting pieces ...

Method and system for quick duplicating video tape

Method and system for fast duplicating video tape are suitable for all the video recorders in helical scan mode and features that the speed of tape transport and the rotating speed of magnetic drum are synchronously increased by n times, so reducing duplicating time by 1/n times. The system is composed of master servo circuit, magnetic drum servo circuit and video circuit. The compare signal and reference signal frequencies in both servo circuits are locked proportionally.

Method for preparing seaweed biological long-acting fertilizer

The invention relates to a method for preparing seaweed biological long-acting fertilizer. Seaweed dregs from which seaweed gum, carrageenan and agar are extracted are taken as an active carrier so as to turn waste into treasure, and a plurality of seaweed bio-active substances contained in seaweed extract and chelated-type nutritive elements or nutrients easily absorbed by plants are all wrapped up to form a slow-release system so as to ensure slow long-term release of fertilizer efficiency and provide plants with demand for nutrition throughout a growing season. The method extracts nutrient components in seaweed adopting a low-temperature extraction process, thereby ensuring that active components of the seaweed are not destroyed and increase the content of the effective nutrient components of products. The method adopts a special biochemical process, adds a multifunctional fermentation strain which has synergy and is formed mainly by compounding fungi, yeast, actinomycetes and bacterial ...

Ascophyllum nodosum fucoidin and preparation and purification method thereof

The invention belongs to the technical field of polysaccharide preparation processes, and particularly relates to ascophyllum nodosum fucoidin and a preparation and purification method thereof. The ascophyllum nodosum fucoidin is prepared from ascophyllum nodosum through ethanol reflux and calcium chloride extraction processes assisted by means of centrifugation, evaporation, concentration and the like, the preparation method is simple, the raw materials are easy to obtain, the cost is low, and the method is suitable for industrial production. And it is further verified that mannuronic acid, mannose, rhamnose, glucuronic acid, glucose and galactose in the ascophyllum nodosum fucoidin account for monosaccharide components.

Preparation method of carrageenan oligosaccharides

The invention relates to a preparation method of carrageenan oligosaccharides. The preparation method sequentially comprises a raw material pretreatment process step, an extraction process step, an enzymolysis process step, a potassium chloride dissolution process step, a potassic alteration and dehydration process step, a squeezing process step, a sterilization process step, a crushing process step and a material mixing and re-sterilization process step, wherein an irradiation and degradation process step is further contained between the crushing process step and the material mixing and re-sterilization process step, and the irradiation and degradation process step is as follows: a semi-finished product obtained in the crushing process step is simply bagged and packaged, and then irradiated by an electronic accelerator with 10MeV and beam power of 500-650kW for 10-20h. A complex enzyme adopted by the invention has stronger destructive power against cellulose and high degree of carrageenan ...

Method for preparing seaweed biological long-acting fertilizer

The invention relates to a method for preparing seaweed biological long-acting fertilizer. Seaweed dregs from which seaweed gum, carrageenan and agar are extracted are taken as an active carrier so asto turn waste into treasure, and a plurality of seaweed bio-active substances contained in seaweed extract and chelated-type nutritive elements or nutrients easily absorbed by plants are all wrappedup to form a slow-release system so as to ensure slow long-term release of fertilizer efficiency and provide plants with demand for nutrition throughout a growing season. The method extracts nutrientcomponents in seaweed adopting a low-temperature extraction process, thereby ensuring that active components of the seaweed are not destroyed and increase the content of the effective nutrient components of products. The method adopts a special biochemical process, adds a multifunctional fermentation strain which has synergy and is formed mainly by compounding fungi, yeast, actinomycetes and bacterial ...

Riveting and positioning tool for side wall framework of public bus

The riveting and positioning tool for the side wall framework of the public bus is short in tool switching time, high in universality, high in positioning precision and convenient to operate and use.The utility model comprises a rack, a handrail and a floor, wherein the handrail and the floor are arranged on the rack; the clamping device further comprises a side stand column, an upper clamping mechanism, a lower clamping mechanism, an upper T-shaped sliding groove and a lower T-shaped sliding groove. The upper T-shaped sliding groove and the lower T-shaped sliding groove are formed in the upper portion and the lower portion of the rack correspondingly. The upper clamping mechanism is in sliding fit with the upper T-shaped sliding groove. The lower clamping mechanism is in sliding fit withthe lower T-shaped sliding groove. The upper clamping mechanism comprises a positioning pin, the side stand column is provided with a reference positioning hole, the reference positioning hole is matched ...