JP5582341B2 - Relief valve with relief pressure change function - Google Patents

Description

  The present invention relates to a relief valve, and more particularly to a relief valve capable of changing a relief pressure used for adjusting hydraulic pressure of an engine lubrication system.

  When the pressure in the hydraulic circuit becomes equal to or higher than a set pressure, the relief valve suppresses an increase in pressure in the hydraulic circuit by opening an excess oil relief passage provided in the relief valve.

  This type of relief valve includes, for example, a body, a valve, a spring, a retainer, a plug, an oil passage for introducing oil between the retainer and the plug, and a back pressure control valve for controlling the oil introduction, as in Non-Patent Document 1. Consists of.

  In this relief valve, when oil is not introduced between the retainer and the plug, the retainer is at the plug end face position, the spring length is set long, and the valve opening pressure is set to a low pressure. On the other hand, when oil is introduced between the retainer and the plug, the retainer rises to contract the spring, and the valve opening pressure is set to a high pressure.

Official technical number 2006-505946

  As an example of the relief valve with the relief pressure changing function, the configuration shown in FIGS. 10 and 11 can be assumed. That is, in this comparative example, the valve body 2 having the first port 11 connected to the supply flow path 10 to which the fluid is supplied from the oil pump 20 and the second port 12 for discharging the fluid is disposed along the axis X. A storage space is formed. A sleeve 4 is provided so as to be movable along the axis X with respect to the housing space, a valve 5 is provided inside the sleeve 4 so as to be movable along the axis X, and a spring 6 that projects and biases the valve 5 is provided. It has. An inflow hole 7 that communicates with the first port 11 is formed at the end of the sleeve 4, and a discharge port 8 that communicates with the second port 12 is formed at the side surface. A shaft-shaped guide body 25 that is in sliding contact with the inner surface of the sleeve 4. Is provided in the valve body 2.

  The sleeve 4 is formed with a first sliding contact surface 4a having a predetermined diameter and a second sliding contact surface 4b having a diameter larger than the first sliding contact surface 4a, and an end surface at a short portion of the first sliding contact surface 4a. 4A is formed, and a back surface 4B is formed at the end on the second sliding contact surface 4b side. A back pressure space B is formed in a region of the housing space facing the back surface 4B, and a control oil passage 16 for supplying fluid pressure to the back pressure space B is formed. When fluid is supplied through the control oil passage 16, the sleeve 4 is moved to the low pressure functional position at the operating end on the first port side by the fluid pressure acting on the back surface 4B of the sleeve 4 as shown in FIG. When the fluid in the back pressure space B is discharged from the control oil passage 16 (pressure is removed), the sleeve 4 is moved to the high pressure functional position at the opposite end of the first port 11 as shown in FIG. It can be moved.

  In the relief valve configured as described above, when the sleeve 4 is set to the high pressure function position and then switched to the low pressure function position, it is ideal to apply the fluid pressure to the entire back surface 4B of the sleeve 4. In order to quickly apply the fluid pressure to the entire surface, the back surface 4B needs to be lifted slightly from the inner wall surface of the back pressure space B. Therefore, it is conceivable to provide a stopper S at the end of the guide body 25 as shown in the figure. However, when this stopper is single, a single back surface 4B of the sleeve 4 set at the high pressure functional position and a single stopper are provided. Since the stopper S comes into contact with the axis X at a position away from the shaft core X, it is considered that a part of the first sliding contact surface 4a and the second sliding contact surface 4b of the sleeve 4 is in a state of strongly contacting the housing space. .

  In such a situation where a biased force acts on the sleeve 4, when fluid is supplied to the back pressure space B in a state where the sleeve 4 is in the high pressure functional position, friction is caused by a portion that contacts by the biased force. It has been considered that the movement of the sleeve 4 is delayed and the response speed is lowered. In particular, when uneven contact occurs in this way, uneven wear is also caused and there is room for improvement.

  An object of the present invention is to eliminate the action of pressure that is biased when the sleeve reaches the operating end in a relief valve that switches the relief pressure by changing the position of the sleeve.

A feature of the present invention is that a valve body having a first port through which fluid flows and a second port through which fluid is discharged;
The valve body has a cylindrical shape centered on the shaft core so as to slide within an accommodation space formed along the shaft core, and an inflow port communicating with the first port, and the second port. A sleeve with a communicating outlet;
The sleeve slides in the direction along the axis while receiving the pressure of the fluid from the first port, closes the outlet near the inlet, and is separated from the inlet. A valve that creates an open state in which the fluid from the inlet is discharged from the outlet;
An urging member for applying an urging force to the valve in a direction against the fluid pressure from the first port;
By applying fluid pressure to the back surface of the sleeve opposite to the first port, the sleeve is set at the low pressure function position on the first port side, and the action of fluid pressure on the back surface is released. A valve position changing mechanism for setting the sleeve to a high-pressure functional position on the opposite side of the first port with a fluid pressure acting on an end surface of the sleeve on the first port side;
A stopper for setting a movement limit of the sleeve in the direction of the high-pressure function position is centered on the shaft core, and is arranged at equal intervals in a circumferential region centering on the shaft core at a position surrounding the shaft core. A plurality of points are formed.

According to this configuration, since the stopper is formed at a position surrounding the shaft center around the shaft core, in a state where the sleeve is set at the high pressure functional position, by contacting the stopper, By determining the movement limit, a gap is secured between the back surface of the sleeve and the inner wall surface of the valve body. At the same time, the disadvantage that biased pressure acts on the sleeve can be eliminated, and the posture of the sleeve can be stabilized and held.
As a result, in the relief valve that switches the relief pressure by changing the position of the sleeve, the action of the biased pressure when the sleeve reaches the operating end is eliminated, the response is improved, and the biased wear can be eliminated. .
In addition, pressure is applied evenly by a stopper formed at equal intervals in a circumferential area centered on the shaft core, and hydraulic fluid can be supplied and discharged through the space of the gap of the stopper, so that the low pressure function position Switching to a high function position can be performed quickly.

  According to the present invention, the valve body is provided with a guide body formed on the outer periphery of a guide surface that is slidably contacted with the inner surface of the sleeve by being fitted into the inner space of the sleeve, and the stopper is provided at a base end position of the guide body. May be formed integrally, and a groove portion having a smaller diameter than the guide surface may be formed between the stopper and the guide surface.

  According to this, a groove with a smaller diameter than the guide surface is formed between the guide body, the guide surface and the stopper, so that the tool reaches the stopper even if the tool for finishing the guide surface overhangs in the groove. Thus, unnecessary processing is not performed, and processing becomes easy.

It is a figure which shows the relief valve in a low-pressure function state. It is a figure which shows the relief valve of a relief state in a low-pressure function state. It is a figure which shows the relief valve in a high-pressure function state. It is a figure which shows the relief valve of a relief state in a high-pressure function state. It is a perspective view which shows the structure of a sleeve. It is sectional drawing which shows the structure of a stopper. It is the top view and perspective view which show the structure of a stopper. It is sectional drawing which shows the structure of the stopper of another embodiment (a). It is the top view and perspective view which show the structure of the stopper of another embodiment (a). It is a figure which shows the relief valve of the comparative example of a low-pressure function state. It is a figure which shows the relief valve of the comparative example of a high pressure functional state.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIGS. 1 to 5, a relief valve 1 with a relief pressure changing function is constructed in which a sleeve 4 is accommodated in the valve body 2 and the relief pressure can be switched by accommodating the valve 5 in the sleeve 4. Has been.

  This relief valve 1 is provided in an oil passage system that sucks fluid (oil) of an oil pan 21 of an engine by an oil pump 20 driven by the engine and supplies the fluid to an engine lubrication system. The relief pressure is switched by switching the position of the sleeve 4 by operating the valve 15 (the switching operation mode will be described later). In addition, the relief valve 1 of the present invention may use a liquid other than oil, such as water, as a fluid to be controlled, or a gas as a control object.

  The valve body 2 is supplied with fluid (oil) from the oil pump 20, the first port 11 into which fluid (oil) from the supply channel flows, and the fluid is discharged. A second port 12 and a housing space formed along the axis X at a position communicating with the first port 11 and the second port 12 are provided.

  The accommodation space has a structure in which a cylindrical inner surface having a predetermined inner diameter is formed on the first port 11 side, and a cylindrical inner surface having a diameter larger than the predetermined inner diameter is formed on the opposite side of the first port 11. The first port 11 communicates with one end of the housing space in the direction along the axis X, and the second port 12 communicates from a direction perpendicular to the axis X in the middle of the direction along the axis X. doing. Further, a back pressure space B is formed at the end of the accommodating space opposite to the first port 11, and a control oil passage 16 communicating with the back pressure space B is formed in the valve body 2.

  The sleeve 4 is accommodated so as to be movable in the direction of the axis X while being in sliding contact with the inner surface of the accommodation space, and further the valve 5 is movable in the direction of the axis X while being in sliding contact with the inner surface of the sleeve 4. Is housed. A shaft-shaped guide body 25 that guides the sleeve 4 by being fitted to the inner periphery of the sleeve 4 opposite to the first port 11, and a spring 6 that biases the valve 5 in the direction of the first port 11 (a biasing member). Example).

  The sleeve 4 has a cylindrical shape with the axial center X as a whole and an inflow port 7 formed at the end, a plurality of discharge ports 8 formed on the side surface, and a single open port 9 formed. . In addition, an end face 4A is formed at the end of the sleeve 4 that faces the first port 11, and a flat back face 4B is formed on the opposite side. A first sliding contact surface 4a that fits in a portion having a predetermined inner diameter of the housing space is provided in a region near the end surface 4A of the sleeve 4, and a second sliding member that fits in a large diameter portion of the housing space in a region near the back surface 4B. An outer peripheral surface 4c having a diameter smaller than the inner diameter of the housing space so as not to slide on the inner wall of the housing space in an intermediate region between the first sliding contact surface 4a and the second sliding contact surface 4b. Is formed.

  In addition, since the outer peripheral surface 4c that does not slide on the inner wall of the housing space is provided, the sliding resistance when the sleeve 4 is operated is reduced. The opening 9 is formed at a position for allowing the fluid on the back side of the valve 5 to escape to the second port 12 when the valve 5 is operated as the pressure in the supply flow path 10 increases.

  As shown in FIG. 5, the end surface 4 </ b> A of the sleeve 4 has a flat outer peripheral surface over the entire circumference, a flat inner peripheral surface over the entire circumference located on the first port 11 side from the outer peripheral surface, and an outer peripheral surface. An inclined surface that is inclined in a direction in which the diameter decreases from the inner peripheral surface to the inner peripheral surface is formed. Furthermore, a notch 4d is formed on the end surface 4A from the inner peripheral surface to the outer peripheral surface. Due to such a structure, when the sleeve 4 operates toward the first port 11, the end surface 4 </ b> A contacts the contact surface 2 </ b> A on the first port side of the valve body 2. At this time, the end surface 4A and the contact surface 2A are in close contact with each other, so that the fluid passage to the outer peripheral surface of the end surface 4A is narrowed, and the fluid of the first port may not easily flow to the outer peripheral surface of the end surface 4A. In order to eliminate such inconvenience, a notch 4d is formed in the end face 4A. From such a structure, the fluid of the first port 11 flows into the entire outer peripheral surface of the end surface 4A through the notch 4d, and the fluid pressure of the first port 11 reaches the outer peripheral surface of the end surface 4A, so that the operation of the sleeve 4 is performed. It is smooth.

  The valve 5 has a shaft shape having an outer diameter that fits inside the inner space of the sleeve 4, and is provided so as to be movable along the shaft core X while being in contact with the inner surface of the sleeve 4. A spring accommodating space is formed along the axis X inside, and the aforementioned spring 6 is interposed between the spring accommodating space and the guide body 25.

  As shown in FIGS. 6 and 7, the guide body 25 is formed in a posture orthogonal to the plate 27 via a base portion 26 having a larger diameter than the guide body 25. By connecting the plate 27 to the valve body 2 with bolts 28, the back pressure space B is formed by integrating with the valve body 2 and closing the accommodation space. The guide body 25 is arranged around the axis X, and the guide body 25 has a boundary portion with the base portion 26 (at a position near the plate 27) centered on the axis X. A plurality of stoppers S are integrally formed at a position surrounding the shaft core X.

  The stopper S determines the limit of movement of the sleeve 4 in the direction of the back pressure space B. The contact surfaces of the plurality of stoppers S are in contact with the back surface 4B of the sleeve 4 in the longitudinal direction of the sleeve 4. Each contact surface is formed at a position that coincides with a virtual plane in a posture orthogonal to the axis X so as to be maintained parallel to the axis X. The stopper S functions to maintain the distance between the back surface 4B of the sleeve 4 and the inner surface of the plate 27 (an example of the inner surface of the valve body 2) at a predetermined value. Thus, when the movement limit of the sleeve 4 is determined, the plurality of stoppers S determine the movement limit of the sleeve 4, so that it is possible to suppress the disadvantage that a biased force acts on the sleeve 4.

  In particular, in the relief valve 1 with a relief pressure changing function of the present invention, when the sleeve 4 moves along the axis X, the inner surface of the sleeve 4 moves in a state of sliding contact with the guide surface 25a on the outer periphery of the guide body 25. Will do. The guide surface 25a is processed and finished with high accuracy, and the guide is placed between the guide surface 25a and the stopper S so that the tool does not unnecessarily cut the stopper S during processing with high accuracy. A groove portion 25b having a smaller diameter than the surface 25a is formed.

  Further, the switching valve 15 is formed with an intermediate oil passage 14 so that the hydraulic oil pressure from the supply passage 10 is applied to the control oil passage 16. The intermediate oil passage 14, the switching valve 15, and the control oil passage 16 constitute the valve position changing mechanism of the present invention.

[Operating form]
With this configuration, by operating the switching valve 15 to the supply position, as shown in FIGS. Supplied to the pressure space B, the sleeve 4 is set to the low pressure function position (low pressure function state). In other words, the fluid pressure acts on the end surface 4A of the sleeve 4 from the first port 11 and simultaneously acts on the back surface 4B of the sleeve 4, and the sleeve 4 has the first pressure due to the difference in pressure receiving area between the end surface 4A and the back surface 4B. The outer peripheral portion of the end surface 4A of the sleeve 4 reaches the moving end of the low pressure function position where it contacts the contact surface 2A of the valve body 2.

  When the pressure in the supply flow path 10 rises with the sleeve 4 set at the low pressure function position, the valve 5 moves from the first port 11 against the biasing force of the spring 6 as shown in FIG. When the sleeve 4 is displaced in the direction of separation and the end of the sleeve 4 reaches the position of the discharge port 8, the surplus fluid in the first port 11 is discharged from the discharge port 8 to the second port 12 and returned to the oil pan. It functions as a relief valve.

  On the other hand, by operating the switching valve 15 to the discharge position, as shown in FIGS. 3 and 4, the pressure from the fluid in the supply flow path 10 is interrupted, and at the same time, the fluid in the control oil path 16 flows. The sleeve 4 is discharged, and the sleeve 4 is set at the high pressure function position (high pressure function position). That is, when the engine is in operation, the fluid pressure always acts on the end surface 4A of the sleeve 4 from the first port 11 and the fluid pressure acting on the back surface 4B of the sleeve 4 disappears. The sleeve 4 reaches the moving end of the high pressure function position from the fluid pressure, and the back surface 4B of the sleeve 4 contacts the stopper S and reaches the limit position.

  When the pressure of the supply flow path 10 rises with the sleeve 4 set to the high pressure function position, the valve 5 moves from the first port 11 against the biasing force of the spring 6 as shown in FIG. When the sleeve 4 is displaced in the direction of separation and the end of the sleeve 4 reaches the position of the discharge port 8, the surplus fluid in the first port 11 is discharged from the discharge port 8 to the second port 12 and returned to the oil pan. It functions as a relief valve. When the sleeve 4 functions as a relief valve with the sleeve 4 set at the high pressure function position, the sleeve 4 has reached the limit position. Therefore, when the sleeve 4 functions as the relief valve, the sleeve 4 is set at the low pressure function position. Compared to the above state, the compression amount of the spring 6 is large and the relief pressure is high.

  As described above, according to the present invention, the relief pressure can be switched by operating the switching valve 15 to change the position of the sleeve 4 using the pressure of the fluid. Further, when the relief pressure is switched, there is no need to use a mechanical operating system as in the case of adjusting the spring pressure using an actuator such as an electric motor, and the configuration is simplified.

  In particular, by arranging a plurality of stoppers S around the shaft core X as in the present invention, a plurality of back surfaces 4B of the sleeve 4 are formed by the fluid pressure acting on the end surface 4A of the sleeve 4. When it is displaced to a position where it comes into contact with the stopper S, the plurality of stoppers S receive the pressure from the back surface 4B evenly. For this reason, the fluid pressure acting on the sleeve 4 does not act in a direction that is biased with respect to the sleeve 4 (a direction that is not parallel to the axis X), while suppressing uneven wear, and at the same time, the back pressure space B When the fluid pressure acts on the sleeve 4, the sleeve 4 can be started quickly, and the response speed when switching the relief pressure is increased.

[Another embodiment]
The present invention may be configured as follows in addition to the embodiment described above.

(A) As shown in FIGS. 8 and 9, a plurality of arc-shaped stoppers S are formed in a circumferential region around the axis X so as to divide this region into a plurality of regions. By forming the stopper S in such a manner that the circumferential region is divided in this way, the wide surface of the plurality of stoppers S can be brought into contact with the back surface 4B of the sleeve 4 so that the inclination of the sleeve 4 can be reliably suppressed. To do.

(B) The stopper S is formed integrally with the sleeve 4 so as to protrude from the back surface 4B of the sleeve 4 along the axis X. As described above, as a structure in which the stopper S is formed integrally with the sleeve 4, a plurality of stoppers S may be formed at a position surrounding the shaft core X in the same manner as in the above-described embodiment, or as another embodiment (a). Alternatively, it may be formed in the entire circumferential region centered on the axis X. In the case where the stopper S is formed integrally with the sleeve 4 as described above, the entire outer periphery of the guide body 25 can be formed as the guide surface 25a, so that the processing becomes easy.

(C) The stopper S is formed on the valve body 2 made of a member such as the plate 27. As a structure for forming the stopper S in the valve body 2 as described above, a plurality of stoppers S may be formed at a position surrounding the shaft core X as in the above-described embodiment, or a shaft as shown in [another embodiment] (a). You may form in the whole area | region of circular shape centering on the core X. FIG. Moreover, the structure which attaches the member which comprises the stopper S to the plate 27, the valve body 2, etc. as a structure, and is formed integrally with the plate 27, the valve body 2, etc. may be sufficient.

  The relief valve according to the present invention is not limited to adjusting the hydraulic pressure of the engine lubrication system, and can be widely used for various hydraulic pressure adjustments.

2 Valve body 4 Sleeve 4A End face 4B Back face 5 Valve 6 Biasing member (spring)
7 Inflow port 8 Discharge port 11 1st port 12 2nd port 25 Guide body 25b Groove S Stopper X Shaft core

Claims (2)

A valve body having a first port through which fluid flows and a second port through which fluid is discharged;
The valve body has a cylindrical shape centered on the shaft core so as to slide within an accommodation space formed along the shaft core, and an inflow port communicating with the first port, and the second port. A sleeve with a communicating outlet;
The sleeve slides in the direction along the axis while receiving the pressure of the fluid from the first port, closes the outlet near the inlet, and is separated from the inlet. A valve that creates an open state in which the fluid from the inlet is discharged from the outlet;
An urging member for applying an urging force to the valve in a direction against the fluid pressure from the first port;
By applying fluid pressure to the back surface of the sleeve opposite to the first port, the sleeve is set at the low pressure function position on the first port side, and the action of fluid pressure on the back surface is released. A valve position changing mechanism for setting the sleeve to a high-pressure functional position on the opposite side of the first port with a fluid pressure acting on an end surface of the sleeve on the first port side;
A stopper for setting a movement limit of the sleeve in the direction of the high-pressure function position is centered on the shaft core, and is arranged at equal intervals in a circumferential region centering on the shaft core at a position surrounding the shaft core. relief pressure change function relief valve is a plurality formed. The valve body is provided with a guide body formed on the outer periphery with a guide surface slidably contacting the inner surface of the sleeve by being fitted into the inner space of the sleeve, and the stopper is integrally formed at a base end position of the guide body. is formed, said relief pressure change function relief valve of claim 1, wherein the diameter to become the groove than the guide surface is formed between the stopper and the guide surface.

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