KR20180085936A - Hydraulic pressure control device for a variable oil pump - Google Patents

Abstract

The hydraulic control apparatus for a variable oil pump according to one aspect of the present invention may include a first discharge passage, a second discharge passage, a feedback passage, a relief passage, a control passage and a valve. The hydraulic control device can control the pressure of the oil sucked from the oil pan when the pump gear of the variable oil pump is driven and fed to the main gallery through the oil discharge passage. The first discharge passage may be connected to one side of the oil discharge passage connecting the pump gear and the main gallery, and a part of the oil supplied to the main gallery may be introduced. One side of the second discharge passage may be connected to the pump gear. One side of the feedback passage may be connected to the main gallery to receive the oil pressure of the main gallery. The relief passage may have one side connected to the oil pan. The control passage may be provided inside the variable oil pump and may be connected to an outlet of the first discharge passage, an inlet of the second discharge passage, an outlet of the feedback passage, and an inlet of the relief valve. Wherein the valve is movably disposed in the control passage and selectively opens and closes the connection between the first discharge passage and the second discharge passage and the connection between the feedback passage and the relief passage by the pressure of the oil supplied from the feedback passage, can do. Therefore, the discharge flow rate control and the relief function of the oil pump can be performed with only one valve, so that the structure of the variable oil pump can be simplified and the manufacturing cost can be reduced.

Description

TECHNICAL FIELD [0001] The present invention relates to a hydraulic control apparatus for a variable oil pump,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a variable oil pump, and more particularly, to a hydraulic control apparatus for a variable oil pump in which a discharge amount varies according to a load variation of an engine.

Generally, an oil pump is a component that supplies oil supplied to each constituent part of an engine for lubrication, and is connected to a crankshaft of the engine and receives power. In this case, the discharge flow rate of the oil pump fluctuates in proportion to the engine speed. That is, when the engine speed is increased, the discharge flow rate of the oil pump increases in proportion to the engine speed. The increase in the required flow rate of the engine actually required when the engine speed increases is relatively small as compared with the increase in the oil pump discharge flow rate . For this reason, when the engine speed increases, a larger hydraulic pressure is formed in the engine than necessary. Excessive hydraulic pressure generated may cause a leakage problem and increase the oil pump drive torque, resulting in a problem that adversely affects the fuel economy of the engine. For reference, when the number of revolutions of the engine is low, an oil pump is used which is set so that the discharge flow rate of the oil pump is reduced but the minimum required pressure in the engine is maintained even if the number of revolutions of the engine is minimized.

In order to prevent the above-described excessive formation of the high pressure, variable oil pumps are used. The variable oil pump is a pump capable of varying a discharge flow rate at the same engine speed by using a sliding type gear (hereinafter referred to as a " sliding gear "). However, even if a variable oil pump is used, the formation of high hydraulic pressure due to an increase in the engine speed can be partially alleviated, but the complete elimination is difficult. That is, it is still necessary to develop a technique for preventing the formation of transient pressure in the engine. In order to solve this problem, a relief valve may be provided for restricting the maximum oil pressure to be formed in the engine by returning the oil to the oil pan when the oil pressure in the engine excessively rises. As a result, the structure of the oil pump becomes complicated.

On the other hand, the variable oil pump requires power for moving the sliding gear in response to the hydraulic pressure of the engine. This power can be generated by supplying a part of the oil discharged from the oil pump to the sliding gear under a specific condition, which may be possible by installing a separate oil transfer passage and a valve. As described above, the conventional variable-type oil pump may have a complicated structure due to the relief valve, the oil transfer passage, and the oil transfer valve, which may raise the manufacturing cost.

The present invention provides a variable oil pump capable of limiting the pressure of oil supplied to the engine through a simple structure.

The hydraulic control apparatus for a variable oil pump according to one aspect of the present invention may include a first discharge passage, a second discharge passage, a feedback passage, a relief passage, a control passage and a valve. The hydraulic control device can control the pressure of the oil sucked from the oil pan when the pump gear of the variable oil pump is driven and fed to the main gallery through the oil discharge passage. The first discharge passage may be connected to one side of the oil discharge passage connecting the pump gear and the main gallery, and a part of the oil supplied to the main gallery may be introduced. One side of the second discharge passage may be connected to the pump gear. One side of the feedback passage may be connected to the main gallery to receive the oil pressure of the main gallery. The relief passage may have one side connected to the oil pan. The control passage may be provided inside the variable oil pump and may be connected to an outlet of the first discharge passage, an inlet of the second discharge passage, an outlet of the feedback passage, and an inlet of the relief valve. Wherein the valve is movably disposed in the control passage and selectively opens and closes the connection between the first discharge passage and the second discharge passage and the connection between the feedback passage and the relief passage by the pressure of the oil supplied from the feedback passage, can do.

In exemplary embodiments, the valve may include a spool movably disposed within the control passage, and a spring that elastically supports the back surface of the spool toward the feedback passage.

In exemplary embodiments, the spool may include a first closing portion closing the first and second discharge passages, and a second closing portion closing the relief passage.

In exemplary embodiments, the second closing portion may be formed to have a length longer than the length of the first closing portion. The first and second discharge passages may be connected when the pressure of the oil flowing into the feedback passage rises to the first set pressure. The feedback passage and the relief passage may be connected when the pressure of the oil rises to a second set pressure greater than the first set pressure.

In the exemplary embodiments, the first and second discharge passages may be connected when the feedback passage and the relief passage are connected.

In exemplary embodiments, the feedback passage may be disposed adjacent a front surface of the spool to supply the oil to the front of the spool.

In exemplary embodiments, the relief passage may be disposed between the first and second discharge passages and the feedback passage.

According to the present invention described above, one valve can selectively open and close the first and second discharge passages and the relief passage by the pressure of the oil supplied through the feedback passage. Therefore, the discharge flow rate control and the relief function of the oil pump can be performed with only one valve, so that the structure of the variable oil pump can be simplified and the manufacturing cost can be reduced.

1 is a cross-sectional view showing a variable oil pump according to an embodiment of the present invention.
2 is a cross-sectional view showing the structure of the hydraulic control apparatus of the variable oil pump shown in FIG.
3 is an enlarged perspective view of the valve of the oil pressure control apparatus of the variable oil pump shown in Fig.
FIGS. 4 to 6 are sectional views showing the operation of the hydraulic control apparatus of the variable oil pump shown in FIG. 2. FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprises", "having", and the like are used to specify that a feature, a number, a step, an operation, an element, a part or a combination thereof is described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

FIG. 1 is a cross-sectional view showing a variable oil pump according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the structure of a hydraulic control apparatus for a variable oil pump shown in FIG. 1, 1 is an enlarged perspective view of a valve of a hydraulic control device of a pump.

Referring to FIGS. 1 to 3, the variable oil pump according to the present embodiment may include a pump housing 100 and a hydraulic control device 400.

A pump gear can be installed inside the pump housing 100. When the pump gear is driven, oil in the oil pan can be pumped to the main gallery via the oil discharge passage that opens the pump housing and the main gallery. The pump gear may be formed of a pair of gears connected to each other, and at least one of the pair of gears may be configured as a sliding gear slidable for adjusting a gear engagement area. The oil discharged by the pump gear is supplied to the main gallery of the engine, and the gear engagement area of the pump gear varies with the movement of the sliding gear, so that the discharge flow rate may be varied. The pump gear may be rotationally driven by receiving the rotational driving force of the engine through the power transmission gear 10. [ The pump housing 100 may be formed so that one side thereof is opened, and the opened side thereof may be closed by the pump cover 200. The oil may be supplied to the main gallery of the engine through the oil discharge passage formed through the pump housing 100 and / or the pump cover 200.

The hydraulic control apparatus 400 is for controlling the pressure of the oil discharged from the oil pump and may be installed in the pump housing 100 or the pump cover 200. The oil control apparatus 400 may have the control passage 110, the first discharge passage 120, the second discharge passage 130, the feedback passage 140, the relief passage 140 and the valve 300 .

The control passage 110 may be formed long along the horizontal direction of the pump housing 100. The control passage 110 may have a cylinder shape in which the left side surface and the right side surface are clogged. However, the control passage 110 may have other shapes such as a rectangular parallelepiped in addition to the cylinder shape.

The first discharge passage 120 may be formed along the vertical direction at the upper central portion of the pump housing 100. The first discharge passage 120 may have one side connected to the control passage 110 and the other side connected to the oil discharge passage. Accordingly, a part of the oil supplied to the main gallery can be supplied to the control passage 110. Therefore, the first discharge passage 120 can be substantially orthogonal to the control passage 110. In another embodiment, the first discharge passage 120 may be at an acute angle with the control passage 110. The oil can be supplied to the inside of the control passage 110 through the first discharge passage 120.

The second discharge passage 130 may be formed along the vertical direction at the lower central portion of the pump housing 100. The second discharge passage 130 may have one side connected to the control passage 110 and the other side connected to the sliding gear of the pump gear. Accordingly, the sliding gear is moved by the pressure of the oil supplied through the second discharge passage 130, whereby the discharge flow rate of the oil pump can be controlled. On the other hand, the second discharge passage 130 may be substantially orthogonal to the control passage 110. In another embodiment, the second discharge passage 130 may be at an acute angle with the control passage 110. In addition, the second discharge passage 130 may be positioned in a straight line with the first discharge passage 120. That is, the outlet of the first discharge passage 120 and the inlet of the second discharge passage 130 may be formed to face each other with the control passage 110 therebetween. Therefore, the oil in the first discharge passage 120 can be supplied to the second discharge passage 130 along the straight line.

The feedback passage 140 may be formed in the left portion of the pump housing 100. The feedback passage 140 may be connected to the left side of the control passage 110. Further, the feedback passage 140 may be connected to the main gallery or the oil discharge passage. Therefore, the hydraulic pressure in the main gallery or the oil discharge passage can be fed back to the control passage 110 through the feedback passage 140. [

The relief passage 150 may be formed in the pump housing 100. The inlet of the relief passage 150 may be provided in plurality and the outlet of the feedback passage 140 and the outlet of the first discharge passage 120 and / 130 and the control passageway 110 so as to be disposed between the openings. When a plurality of inlets of the relief passage 150 are formed, the inlets of the relief passage 150 can be disposed at positions facing each other with the control passage 110 therebetween. The oil supplied from the feedback passage 140 to the control passage 110 is relieved to the oil pan through the relief passage 150 when the pressure of the variable oil pump, that is, the pressure of the main gallery or the oil discharge passage, .

The valve 300 may be movably disposed within the control passage 110. The valve 300 may be opened or closed by the pressure of the oil supplied from the feedback passage 140. The valve 300 can have both an oil supply function to the pump gear and an oil relief function to the oil pan. One valve 300 having these functions at the same time may include a spool 310 and a spring 320.

The spool 310 may be movably disposed within the control passage 110. [ The spool 310 may have a front face facing the outlet of the feedback passageway 140 and a rear face opposite the front face. The oil supplied through the feedback passage 140 pushes the front surface of the spool 310 so that the spool 310 can be moved rightward in the control passage 110. [

The spool 310 may have a shape corresponding to the shape of the control passage 110. Since the control passage 110 has a cylindrical shape, the spool 310 can also have a substantially cylindrical shape. The spool 310 may have a first closing portion 312 and a second closing portion 314. Each of the first closing portion 312 and the second closing portion 314 is configured such that when the spool 310 is installed inside the control passage 110, the inner wall of the control passage 110 and the first and second closing portions 312 and 314 So that the flow of oil between the front and rear surfaces of the spool 310 can be prevented. Referring to the drawings, each of the first and second closing portions 312 and 314 may be formed integrally with the spool 310 in a shape in which a part of the outer peripheral surface of the spool 310 is expanded. The first closing portion 312 may be formed at the center of the outer peripheral surface of the spool 310. The first closing portion 312 may selectively close the connection of the first and second discharge passages 120 and 130. [ That is, supply of a part of the oil discharged from the oil pump to the sliding gear can be selectively connected. The second closing portion 314 may be formed on the left side of the outer peripheral surface of the spool 310. The second closing portion 314 may selectively connect the connection of the relief passage 150 and the feedback passage 140. The second closing portion 314 may have a longer length than the first closing portion 312.

The spring 320 may elastically support the rear surface of the spool 310 toward the feedback passage 140. The spring 320 can return the spool 310 moved by the pressure of the oil supplied through the feedback passage 140 to the original position. Therefore, when the pressure of the oil supplied through the feedback passage 140 is lower than the tension of the spring 320, the first and second closing portions 312 and 314 of the spool 310 are closed by the first and second discharge passages (120, 130) and the relief passage (150), respectively.

FIGS. 4 to 6 are sectional views showing the operation of the hydraulic control apparatus of the variable oil pump shown in FIG. 2. FIG.

4, when the pressure of the oil supplied through the feedback passage 140 is lower than the tension of the spring 320, the tension of the spring 320 causes the spool 310 to move leftward in the control passage 110 Lt; / RTI > Accordingly, the first and second closing portions 312 and 314 of the spool 310 can close the first and second discharge passages 120 and 130 and the relief passage 150, respectively. Therefore, the oil from the first discharge passage 120 may not be supplied to the pump gear through the second discharge passage 130. Further, the oil fed back from the feedback passage 140 may not be relieved to the relief passage 150. [

5, when the pressure of the oil supplied through the feedback passage 140 becomes higher than the first set pressure higher than the tension of the spring 320, the spool 310 is returned to the spring 320 by the pressure of the oil, The control channel 110 can be moved to the right side while compressing. The first closing portion 312 also moves to the right side, so that the first and second discharge passages 120 and 130 can be opened. Therefore, the oil can be supplied from the first discharge passage 120 to the pump gear through the second discharge passage 130. [ On the other hand, since the second closing portion 314 has a longer length than the first closing portion 312, even if the second closing portion 314 is moved to the right side like the first closing portion 312, The closure 314 may be still closing the relief passage 150. Therefore, the oil fed back through the feedback passage 140 can not be relieved through the relief passage 150 and can continue to push the spool 310. [

Referring to FIG. 6, when the oil pressure in the main gallery continuously rises and becomes higher than the second set pressure that is larger than the first set pressure, the oil fed back through the feedback passage 140 further pushes the spool 310 to the right . Therefore, the second closing portion 314 is further moved to the right side, so that the relief passage 150 can be opened. A portion of the oil fed back through the feedback passage 140 may be relieved to the oil pan through the open relief passage 150. As a result, the pressure of the oil discharged from the variable oil pump can be reduced.

As described above, when the number of revolutions of the engine increases and the oil pressure of the main gallery becomes higher than the first set pressure, the first discharge passage 120 and the second discharge passage 130 are connected by the movement of the spool 310, When the engine speed further increases and the hydraulic pressure in the main gallery rises to the second set pressure higher than the first set pressure, the spool 310 further moves to connect the feedback passage 140 and the relief passage 150, It can be relieved with a fan so that the main gallery pressure does not rise further. That is, as the hydraulic pressure of the main gallery rises, the flow rate control through the movement of the sliding gear and the pressure limitation by the oil relief can be sequentially performed. The spool 310 may be formed in such a shape that the connection between the first discharge passage 120 and the second discharge passage 130 can be maintained when the feedback passage 140 and the relief passage 150 are connected to each other . In this case, even when the oil is relieved by the oil pan, the sliding gear can be maintained in a shifted state. By driving the spool 310, the oil pressure in the main gallery can be controlled even when the number of revolutions of the engine rises, thereby preventing leakage and improving fuel efficiency.

As described above, according to the embodiments, one valve can selectively open and close the first and second discharge passages and the relief passage by the pressure of the oil supplied through the feedback passage. Therefore, the discharge flow rate control and the relief function of the oil pump can be performed with only one valve, so that the structure of the variable oil pump can be simplified and the manufacturing cost can be reduced.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. And changes may be made without departing from the spirit and scope of the invention.

100; Pump housing 110; Control passage
120; A first discharge passage 130; The second discharge passage
140; Feedback path 150; Relief passage
200; Pump cover 300; valve
310; Spool 312; The first closing part
314; A second closure 320; spring
400; Hydraulic control device

Claims (7)

An oil pressure control apparatus for a variable oil pump for controlling a pressure of oil sucked from an oil pan during driving of a pump gear of a variable oil pump and fed to a main gallery through an oil discharge channel,
A first discharge passage through which a part of the oil supplied to the main gallery flows in connection with the oil discharge passage;
A second discharge passage having one side connected to the pump gear;
A feedback passage connected to one side of the main gallery to receive the oil pressure of the main gallery;
A relief passage having one side connected to the oil pan;
A control passage connected to an outlet of the first discharge passage, an inlet of the second discharge passage, an outlet of the feedback passage, and an inlet of the relief passage, the control passage being formed inside the variable oil pump; And
A valve movably disposed in the control passage for selectively opening and closing the connection between the first discharge passage and the second discharge passage and the connection between the feedback passage and the relief passage by the pressure of the oil supplied from the feedback passage, Wherein the hydraulic pump is a hydraulic pump. 2. The valve according to claim 1,
A spool movably disposed in the control passage; And
And a spring for elastically supporting the rear surface of the spool toward the feedback passage. 3. The apparatus of claim 2, wherein the spool
A first closing portion closing the first and second discharge passages; And
And a second closing portion that closes the relief passage. The method of claim 3,
Wherein the first closing portion is formed in a shape that interconnects the first and second discharge passages by the spool which moves in the control passage when the pressure of oil flowing into the feedback passage rises to a first set pressure,
Wherein the second closing portion is formed to have a length longer than the length of the first closing portion, and when the pressure of the oil flowing into the feedback passage rises to the second predetermined pressure, The relief passage being formed in a shape that connects the relief passage,
And the second set pressure is larger than the first set pressure. 5. The method of claim 4,
And the first and second discharge passages are also connected when the feedback passage is connected to the relief passage. 3. The hydraulic control apparatus according to claim 2, wherein the feedback passage is disposed adjacent to a front surface of the spool for supplying the oil to the front surface of the spool. 7. The hydraulic control apparatus according to claim 6, wherein the relief passage is disposed between the first and second discharge passages and the feedback passage.

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