PISTON OIL JET APPARATUS OF ENGINE

This application claims the benefit of priority to Korean Patent Application No. 10-2015-0084255 filed in the Korean Intellectual Property Office on Jun. 15, 2015, the entire content of which is incorporated herein by reference.

The present disclosure relates to a piston oil jet apparatus of an engine. More particularly, the present disclosure relates to a piston oil jet apparatus of an engine, capable of controlling a cooling oil which cools a piston based on a speed and a load of the engine.

In general, an engine comprises a number of driving parts formed of metal, which move while being in contact with each other. When the metal parts move while being in contact with each other, heat due to friction is generated.

To prevent damage of the metal parts due to the frictional heat, a coolant is used, and to reduce the friction between the metal parts, an oil is used for lubrication between the metal parts.

In the engine, the oil flows through each part according to an operation of a hydraulic pump. Then, the oil is supplied to a main oil gallery provided in a cylinder block and supplied to a piston cooling jet connected to the main oil gallery. The piston cooling jet is installed to inject the oil toward the piston.

The oil supplied from the hydraulic pump is always supplied to the piston cooling jet through the main oil gallery, and the piston cooling jet includes a check ball supported by an elastic member therein. Due to the supplied oil, when a pressure of the oil is high, the piston cooling jet is operated in an on-state, and when the pressure is low, the piston cooling jet is operated in an off-state.

Thus, even in a low speed and low load state of the engine, a large amount of the oil is supplied into the piston cooling jet by the driving of the hydraulic pump, thereby super-cooling the piston. Accordingly, fuel consumption of the engine is deteriorated by the driving of the hydraulic pump, and exhaust gas emissions may be exacerbated in the low engine temperature state.

The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.

The present disclosure provides a piston oil jet apparatus of an engine, capable of controlling a cooling oil which cools a piston based on a speed and a load of the engine.

A piston oil jet apparatus of an engine according to an exemplary embodiment of the present inventive concept includes: a control valve guide installed inside a cylinder block which includes a cylinder in which a piston is lifted and including an oil inlet provided at one side and oil supply holes controlling oil supply at another side; a control valve coupled to the control valve guide and opening or closing the oil supply holes; a piston cooling jet connected to the oil supply holes to inject a cooling oil toward the piston; and an actuator moving the control valve.

The control valve may be inserted into the control valve guide to open or close the oil supply holes.

The actuator may be an electric motor rotating the control valve to open or close the oil supply holes.

The control valve guide may be formed of a circular pipe body, and the control valve may contact an interior circumference of the circular pipe body with a curved surface to open or close the oil supply holes in a forward rotation and a reverse rotation.

The cylinder may be provided in plural, and the control valve guide may have an oil supply hole respectively corresponding to each cylinder.

The control valve may include opening/closing members respectively corresponding to the oil supply holes and a rotation shaft connected to and rotating the opening/closing members.

The opening/closing members may have a semicircular shape corresponding to the circular interior circumference of the control valve guide to be connected to the rotation shaft disposed at a center of the control valve guide by a connecting member.

The oil supply holes may be disposed on the same side in a diameter direction of the control valve guide.

The control valve guide may further include bearings provided at both ends, and the control valve may be supported by the bearings.

As described above, according to the exemplary embodiment of the present inventive concept, by installing the control valve guide in the cylinder block and the control valve in the control valve guide and by providing the piston cooling jet in the oil supply hole of the control valve, the actuator may be controlled depending on a speed and a load of the engine since the oil supply hole is controlled by driving the control valve by the actuator.

Accordingly, the cooling oil injected toward the piston from the piston cooling jet may be controlled based on the speed and the load of the engine. That is, piston oil jet apparatus according to the exemplary embodiment may control an injecting time and an injection amount of the cooling oil based on the speed and the load of the engine.

The present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments are shown. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. The drawings and description are to be regarded as illustrative in nature and not restrictive. Like reference numerals designate like elements throughout the specification.

FIG. 1 is a perspective view of a cylinder block including a piston oil jet apparatus of an engine according to an exemplary embodiment of the present inventive concept. Referring to FIG. 1, a piston oil jet apparatus of an engine according to an exemplary embodiment is installed to a cylinder block 3 including a cylinder 2 in which a piston 1 is lifted.

As one example, the piston oil jet apparatus includes a control valve guide 10 installed to the cylinder block 3, a control valve 20 coupled to the control valve guide 10, a piston cooling jet 30 connected to the control valve guide 10, and an actuator 40 controlling the control valve 20.

Referring to FIG. 2, the control valve guide 10 includes an oil inlet 11 installed at one side thereof and oil supply holes 12 controlling an oil supply and installed at another side thereof. The control valve guide 10 is inserted or pressed and installed to a main oil gallery of the cylinder block 3. For example, the control valve guide 10 may be installed to a lower portion of the cylinder block 3.

The control valve guide 10 allows a piston cooling oil supplied from a hydraulic pump (not shown) to flow into the oil inlet 11, and supplies the oil to the piston cooling jet 30 through the oil supply holes 12.

The oil inlet 11 may be formed at a center of the control valve guide 10 in a length direction such that the oil supplied from the main oil gallery flows inside the control valve guide 10. Since the oil inlet 11 is disposed at the center of the control valve guide 10, a distance from the oil inlet 11 to the oil supply holes 12 is reduced and a uniform amount of oil may be supplied.

The oil supply holes 12 are provided at a predetermined interval in the control valve guide 10 to supply the oil. That is, since the piston cooling jet 30 is respectively provided in the oil supply holes 12, the oil may be injected into the piston 1 in the cylinder 2 through the piston cooling jet 30.

The control valve 20 is coupled to the control valve guide 10 to open/close the oil supply holes 12. The piston cooling jet 30 is connected to the oil supply holes 12 of the control valve 20 to inject the piston cooling oil toward the piston 1.

The actuator 40 drives the control valve 20 to close/open the oil supply holes 12. That is, the actuator 40 is variously formed depending on the structure of the control valve 20 of the control valve guide 10, thereby closing/opening the oil supply holes 12.

FIG. 2 is an exploded perspective view of the piston oil jet apparatus of FIG. 1, and FIG. 3 is a coupled partial perspective view of the piston oil jet apparatus of FIG. 2.

Referring to FIGS. 2 and 3, the control valve 20 is inserted into the control valve guide 10, and closes/opens the oil supply holes 12 formed at the control valve guide 10.

The control valve guide 10 may have a circular pipe body, and the oil supply holes 12 may be formed at positions corresponding to the piston cooling jets 30. In the figures, the cylinder block 3 includes four cylinders 2 and pistons 1 such that the control valve guide 10 includes four oil supply holes 12. However, it is not limited thereto.

The control valve 20 contacts an interior circumference of the circular pipe body of the control valve guide 10 with a curved surface to close/open the oil supply holes 12 while rotating in a forward direction and a backward direction. That is, the control valve 20 includes opening/closing members 21 respectively corresponding to the oil supply holes 12 and a rotation shaft 22 connecting the opening/closing members 21 to be rotated.

FIG. 3 is a coupled partial perspective view of the piston oil jet apparatus of FIG. 2. Referring to FIGS. 2 and 3, the opening/closing members 21 have a semicircular shape corresponding to a circular interior circumference of the control valve guide 10.

The opening/closing members 21 are connected to the rotation shaft 22 disposed at the center of the control valve guide 10 by a connecting member. Accordingly, the opening/closing members 21 may open or close the oil supply hole 12 depending on the rotation operation of the rotation shaft 22.

As shown in FIGS. 2 and 3, the control valve guide 10 includes bearings 13 and 14 on respective ends thereof. The rotation shaft 22 of the control valve 20 is fixed in the control valve guide 10 and is supported by the bearings 13 and 14.

The rotation shaft 22 of the control valve 20 is connected to the actuator 40. The actuator 40 may rotate the rotation shaft 22 of the control valve 20, and may be an electric motor which opens/closes the oil supply holes 12 through the opening/closing members 21.

Although not shown, the actuator 40 has a cylinder shape for a linear reciprocating motion such that the control valve 20 provided in the control valve guide 10 is operated in the length direction of the control valve guide 10, thereby closing/opening the oil supply holes 12.

The control valve guide 10 may have the plurality of oil supply holes 12 disposed on the same side in a diameter direction. Further, the opening/closing members 21 of the control valve 20 are disposed corresponding to the oil supply holes 12.

Accordingly, the opening/closing members 21 simultaneously open and close the oil supply holes 12 of the control valve guide 10 depending on the rotation operation of the control valve 20 such that opening amounts of the oil supply holes 12 are the same. That is, the oil supply holes 12 control the amount of the piston cooling oil supplied to a plurality of piston cooling jets 30 to be the same.

Although not shown, the control valve guide 10 may have the oil supply holes 12 disposed at a predetermined interval in a circumferential direction. In addition, the opening/closing members 21 may be disposed corresponding to the oil supply holes 12 at the predetermined interval in a circumferential direction.

Accordingly, as one portion among the oil supply holes 12 is opened depending on the operation of the control valve 20 and another portion is not opened, a portion of the piston cooling jets 30 may supply the oil and another portion may not supply the oil. That is, the piston cooling jets 30 may supply the oil by corresponding to a lifting position of the piston 1 in the cylinder 2.

FIG. 4 is a perspective view showing an off state of the piston oil jet apparatus of FIG. 1, and FIG. 5 is a perspective view showing an on state of the piston oil jet apparatus of FIG. 1.

Referring to FIG. 4, if the opening/closing members 21 of the control valve 20 close the oil supply holes 12 of the control valve guide 10 according to the driving of the actuator 40, the piston cooling oil supplied to the oil inlet 11 of the control valve guide 10 is blocked in the oil supply holes 12. That is, the piston cooling oil is not supplied to the piston cooling jet 30.

Referring to FIG. 5, the opening/closing members 21 of the control valve 20 open the oil supply holes 12 of the control valve guide 10 depending on the driving of the actuator 40, and the piston cooling oil supplied to the oil inlet 11 of the control valve guide 10 is supplied to the oil supply holes 12. That is, the piston cooling oil is supplied to the piston cooling jet 30.

FIG. 6 is a graph showing an on and off region of the piston oil jet apparatus based on a speed and a load of an engine in an engine low temperature state. Referring to FIG. 6, in the engine low temperature state, an on region and an off region where the piston cooling jet 30 is opened and closed based on the engine speed and the engine load are shown.

When the engine is in the low temperature state and is driven with the low speed and the low load, the opening/closing members 21 of the control valve 20 close the oil supply holes 12 of the control valve guide 10 according to the driving of the actuator 40

That is, as the speed of the engine is low and the load of the engine is low, the piston cooling jet 30 maintains the off state.

Since the piston cooling oil is not supplied to the piston 1, the driving of the hydraulic pump may be stopped or an oil supply flow may be reduced. That is, in the engine low temperature state, and in the state of the low speed and the low load of the engine, fuel consumption of the engine may be improved and the exhaust gas may be reduced.

While this invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.