JPH04105676U - oil relief device - Google Patents

Abstract

(57) [Summary] [Purpose] To simplify and downsize the operating section by making it possible to increase or decrease the relief pressure with an extremely small operating force. [Structure] A drain hole 4 and a valve element 5 biased by a spring 6 in a direction to close the drain hole 4 are provided in the valve housing chamber 2 communicating with the discharge side passage 1. A pressure introduction path 10 having an on-off valve 12 in the middle is connected to the chamber 2a, and by operating the pressure in the back chamber 2a with the on-off valve 12, the biasing force of the valve body 5 is changed, thereby increasing or decreasing the relief pressure. .

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention is an oil relief device for oil pumps installed in automobile engines. Regarding.

0002

[Conventional technology]

This type of oil relief device is installed in communication with the discharge side passage of the pump circuit. A drain hole is provided in the valve housing chamber, and a valve body is provided to open and close the drain hole. is installed internally with a spring biased in the valve closing direction (direction that closes the drain hole). , when the fluid pressure in the discharge side passage exceeds the set value, this fluid pressure resists the spring force of the spring. and push back the valve body to allow some of the oil to escape from the drain hole, thereby preventing the oil from being discharged. The hydraulic pressure in the side passage is kept below a set value.

0003 However, in an oil tank where the valve opening pressure (hereinafter referred to as relief pressure) of the valve body is fixed, In the case of a leaf device, it is necessary to set the desired oil discharge pressure according to the engine operating conditions. Conventionally, the relief pressure was adjusted depending on the engine operating conditions. A device that can be adjusted to increase or decrease has also been developed.

0004 This conventional oil relief device has a spring in the valve housing chamber that biases the valve body. An operating section consisting of a cam mechanism, etc. that mechanically switches and operates the set length is provided. This operation section can be moved according to the engine's operating status, such as the number of revolutions and the size of the load. By changing the set length of the spring, the relief pressure can be increased or decreased. It has become.

[0005] still. This similar technique is disclosed in Japanese Utility Model Application Publication No. 63-73510.

[0006]

[Problem that the idea aims to solve]

However, in the conventional oil relief device described above, the spring that biases the valve body is A mechanism that increases or decreases the relief pressure by mechanically manipulating the set length of the ring. Because of the structure, a very large amount of operating force is required to adjust the relief pressure. For this reason, the operation section has been forced to be complicated and large.

[0007] Therefore, the present invention allows the relief pressure to be increased or decreased with extremely small operating force. In this way, we propose an oil relief device that can simplify and downsize the operating section. This is what we are trying to provide.

[0008]

[Means to solve the problem]

This invention is a means to solve the above-mentioned problems. A drain hole is provided in the valve housing chamber communicating with the side passage, and the drain hole is opened and closed. By installing the valve body internally with the valve body biased in the valve closing direction and changing the biasing force of the valve body. In the oil relief device that adjusts the relief pressure by A pressure adjusting means for adjusting the back pressure of the valve body is connected to the back chamber side of the chamber.

[0009] In addition, as another means, a valve housing chamber communicating with the discharge side passage of the pump circuit, and a valve housing chamber communicating with the discharge side passage of the pump circuit; It has a drain hole provided in the storage chamber and a through hole that constantly communicates with the drain hole, and is slidably installed in the valve housing chamber to define an operating pressure chamber within the valve housing chamber. a movable cylinder, and a movable cylinder that is slidably installed inside the movable cylinder and closes the through hole. a valve body that is spring-biased in the direction of The structure includes a pressure adjustment means for adjusting the pressure in the chamber.

0010

[Effect]

In the former case, the pressure introduced into the back chamber of the valve housing chamber may be adjusted using a pressure regulating means. The back pressure of the valve body is controlled by the pressure control, which changes the biasing force of the valve body and increases the relief pressure. Adjust increase/decrease.

[0011] In the latter case, the movable system is By moving the cylinder and manipulating the position of the through hole, the spout leading to the opening of the valve is Adjust the relief pressure by changing the stroke of the ring.

0012

【Example】

Next, embodiments of the present invention will be described based on the drawings.

[0013] First, an embodiment corresponding to claim 1 of the present invention will be described.

[0014] 1 to 3, 1 is the discharge side passage of the pump circuit, and 2 is the discharge side passage of the pump circuit. This is a valve housing chamber that communicates with the side passage 1 through the passage 3. Near the passage 3 of the valve housing chamber 2 On the side wall, the oil is returned to a reserve tank (not shown) or to the suction part of the oil pump. A drain hole 4 is provided. In addition, a drain hole 4 is provided in the valve housing chamber 2 to open and close it. A cylindrical valve body 5 with a bottom, and a valve body 5 that is oriented in the valve closing direction (the direction in which the drain hole 4 is closed). A spring 6 is installed inside to bias the valve body 5 while the fluid pressure in the discharge side passage 1 is low. When the drain hole 4 is closed and the hydraulic pressure increases from there, the valve body 5 is moved by the spring force of the spring 6. The drain hole 4 is opened by sliding inside the valve housing chamber 2 against the pressure. Valve body 5 An annular groove 7 having a predetermined width is formed on the outer circumferential surface of the valve body 5. An orifice 8 of a predetermined diameter is formed to penetrate the surface. Orifice 8 is an annular groove 7 It communicates with the drain hole 4 through the orifice 8. By releasing the oil in the back chamber 2a to the drain hole 4, the valve body 5 can be operated. are doing. In addition, 9 in the figure is a plug that constitutes a part of the valve housing chamber 2, and this plug A group 9 supports one end of the spring 6.

[0015] A pressure introduction path 10 whose one end communicates with the discharge side passage 1 is connected to the back chamber 2a. The hydraulic pressure in the discharge side passage 1 can be introduced into the back chamber 2a through the pressure introduction passage 10. It has become. Also, in the middle of the pressure introduction path 10, a solenoid 11 is operated. An on-off valve 12 is installed, and a solenoid 11 controls the rotational speed of an engine (not shown). It opens and closes in response to signal A and load signal B. The on-off valve 12 is The pressure introduction passage 10 is closed when the engine speed and load are low, and when the engine speed and load are low, When the load rises, the pressure introduction passage 10 is opened and the liquid pressure in the discharge side passage 1 is introduced into the back chamber 2a. do.

[0016] In this embodiment, the pressure adjusting means for adjusting the pressure in the back chamber 2a is a pressure introducing means. It is composed of a passage 10 and an on-off valve 12.

[0017] Due to the above configuration, while the engine speed and load are low, the As shown, the on-off valve 12 closes the pressure introduction path 10 so that no hydraulic pressure is introduced into the back chamber 2a. In this state, the valve body 5 receives the hydraulic pressure in the discharge side passage 1 through the passage 3. Ru. In this state, when the fluid pressure in the discharge side passage 1 increases, the fluid pressure increases as shown in FIG. begins to push back the valve body 5 against the elastic force of the spring 6, and the discharge side passage 1 When the fluid pressure reaches the set value (relief pressure on the low pressure side), the valve body 5 opens the drain hole 4. When the oil is opened, some of the oil escapes to the drain hole 4, and the hydraulic pressure in the discharge side passage 1 is reduced to the low pressure side. Keep it below a certain value.

[0018] Also, when the engine speed or load exceeds a certain value, as shown in Figure 3, The on-off valve 12 opens the pressure introduction passage 10 so that the liquid pressure in the discharge passage 1 flows into the back chamber 2a. As a result, the back pressure of the valve body 5 is increased, and the force of the spring 6 and this back pressure are increased. The biasing force of the valve body 5, which is a combined force with the pressure, is also increased. In addition, the discharge side passage 1 and the back chamber 2 When a is opened, a part of the oil that has flowed into the back chamber 2a through the pressure introduction path 10 is turned off. Since the liquid pressure that acts on the back chamber 2a escapes to the drain hole 4 via the orifice 8, 5 is smaller than the hydraulic pressure acting on the surface on the passage 3 side.

[0019] In this state, when the fluid pressure in the discharge side passage 1 increases, the liquid is introduced through the passage 3. The hydraulic pressure in the discharge side passage 1 pushes back the valve body 5 against the force, and the hydraulic pressure increases. When the set value (relief pressure on the high pressure side) is reached, the valve body 5 opens the drain hole 4 and drains the oil. A part of the fluid is released to keep the fluid pressure in the discharge side passage 1 below the set value on the high pressure side. in this case The biasing force of the valve body 5 is a composite force of the force of the spring 6 and the back pressure, so the relief The pressure is higher than when the engine speed and load are low.

[0020] Next, another embodiment corresponding to claim 1 of the present invention will be described.

[0021] 4 and 5, the valve housing chamber 2 is in communication with the discharge side passage 1 via the passage 3, A first drain hole 13 and a second drain hole 14 are provided in the outer peripheral wall. So Further, in the valve housing chamber 2, a valve body 5 for opening and closing the first drain hole 13 is fitted with a spring. It is slidably accommodated in a biased state by the rod 6. There is a hole in the second drain hole 14. A check valve 15 is provided, which is activated when the fluid pressure in the back chamber 2a exceeds a set value. The check valve 15 is opened. Furthermore, the opening pressure of the check valve 15 is , so as to be greater than the opening pressure of the valve body 5 when the engine speed and load are small. is set to . The back chamber 2a includes a pressure introduction passage 1 whose one end communicates with the discharge passage 1. 0 is connected, and a third drain hole 16 branches off in the middle of this pressure introduction path 10. It is provided. Further, the third drain hole 16 portion of the pressure introduction path 10 A switching valve 17 is interposed between the solenoid 11 and the return valve 17. By being switched by the force of the spring 18, the back chamber 2a becomes the discharge side passage 1, Alternatively, it may be electrically connected to the second drain hole 16. Also, solenoid 11 operates in response to rotational speed signal A and load signal B in the same way as shown in Figures 1 to 3. , when the engine speed or load is low, the switching valve 17 switches between the back chamber 2a and the third drain. the switching valve 1 when the engine speed or load is high. 7 connects the back chamber 2a and the discharge side passage 1.

[0022] In the case of this embodiment, the pressure adjusting means includes the pressure introduction path 10 and the third drain hole 1. 6, a switching valve 17, and a check valve 15.

[0023] With the above configuration, this oil relief device reduces engine rotation. While the rotation speed and load are small, the switching valve 17 is closed to the third drain hole 16 as shown in FIG. The valve body 5 is switched to the opening side and the hydraulic pressure in the back chamber 2a becomes the drain pressure. In this state, the fluid pressure of the discharge side passage 1 is received through the passage 3. In this state, the discharge side When the hydraulic pressure increases, the hydraulic pressure introduced through the passage 3 resists the force of the spring 6. Push back the valve body 5, open the drain hole 4, let some of the oil escape, and drain the discharge side passage. Keep the pressure in step 1 below the set value on the low pressure side.

[0024] Also, when the engine speed or load exceeds a certain value, as shown in Figure 5, The switching valve 17 is switched to the side that opens the pressure introduction passage 10 so that the discharge side passage 1 is opened. Hydraulic pressure is introduced into the back chamber 2a. Then, the liquid pressure in the back chamber 2a increases, so the valve body 5 Once returned by the spring 6, the first drain hole 13 is closed. From this state, as the hydraulic pressure in the discharge side passage 1 increases, the hydraulic pressure in the back chamber 2a increases to the check valve 1. When the pressure increases to the valve opening pressure of 5, the check valve 15 opens the second drain hole 14 and drains the back chamber. A part of the oil in the back chamber 2a is released from the second drain hole 14 to lower the liquid pressure in the back chamber 2a. Let it go down. When the liquid pressure in the back chamber 2a decreases in this way, the differential pressure between the passage 3 and the back chamber 2a The valve body 5 moves to open the first drain hole 13 and drain the oil in the discharge side passage 1. A portion of the fluid is released from the first drain hole 13 to keep the fluid pressure below the set value on the high pressure side. still, In this embodiment, the relief pressure on the high pressure side is set by the opening pressure of the check valve 15. be done.

[0025] Next, an embodiment corresponding to claim 2 of the present invention will be described.

[0026] In FIG. 6, 2 is a valve housing chamber 2 connected to the discharge side passage 1 via a passage 3. This valve housing chamber 2 is provided with a drain hole 4 that allows oil introduced into the interior to escape. At the same time, a substantially cylindrical movable cylinder 19 is slidably installed inside. this The movable cylinder 19 has a small diameter portion 20 with a small outer diameter formed at one end, and a slider at the other end. When biased by the pull 21, this small diameter portion 20 is located on the passage 3 side of the valve housing chamber 2. It is slidably fitted into the end of the The inner circumferential surface of the valve housing chamber 2 and this small diameter portion 20 is an operating pressure chamber 22 for operating the movable cylinder 19. It becomes. In addition, the side wall of the general part of the movable cylinder 19 has a hole penetrating its inner and outer surfaces. A through hole 23 is formed, and the inside of the movable cylinder 19 is driven through this through hole 23. It communicates with the lane hole 4. In addition, the diameter of the drain hole 4 is sufficiently large. The through hole 23 is always a drain hole regardless of the moving position of the movable cylinder 19. It is designed to communicate with 4.

[0027] 24 is a valve body slidably installed inside the movable cylinder 19; The spring 25, one end of which is supported by the end wall of the valve housing chamber 2, connects the passage in three directions. is energized by Also, inside the valve body 24, from the end on the passage 3 side to the outer circumferential surface. A communication passage 26 is formed in the outer peripheral surface of the valve body 24. An annular groove 27 is formed in the portion where the end portion of 26 is open. This annular groove 27 , while the fluid pressure in the discharge side passage 1 is extremely small and the valve body 24 is located on the passage 3 side. , is offset from the through hole 23 of the movable cylinder 19, but the hydraulic pressure in the discharge side passage 1 rises and the valve body 24 is displaced by a predetermined amount, it communicates with the through hole 23 and the discharge side passage 1 A portion of the oil is released into the drain hole 4.

[0028] Moreover, 28 is a pressure introduction for introducing the hydraulic pressure of the discharge side passage 1 into the working pressure chamber 22. In the middle of this pressure introduction path 28, there is an opening actuated by the solenoid 11. A closing valve 12 is interposed. This solenoid 11 is similar to the two embodiments described above. It is designed to open and close in response to engine speed signal A and load signal B. . In this embodiment, the pressure adjusting means for adjusting the pressure in the working pressure chamber 22 is It is composed of a force introduction path 28 and an on-off valve 12.

[0029] In the case of this oil relief device, it opens and closes only when the engine speed and load are low. The valve 12 closes the pressure introduction path 10 and no hydraulic pressure is introduced into the operating pressure chamber 22. For this reason, the valve body 24 is pushed by the spring 21 as shown in FIG. It is located on the aisle 3 side. If the fluid pressure in the discharge side passage 1 increases in this state, this The fluid pressure pushes back the valve body 24 against the spring force of the spring 21, and the discharge side When the hydraulic pressure in the passage 1 reaches the set value, the annular groove 27 of the valve body 24 closes the movable cylinder 1. 9, and a part of the discharge side passage 1 is drained through this through hole 23. The liquid pressure in the discharge passageway 1 is kept below the set value on the constant pressure side.

[0030] Also, when the engine speed or load exceeds a certain value, the on-off valve 1 2 opens the pressure introduction passage 28 and the hydraulic pressure in the discharge side passage 1 is introduced into the working pressure chamber 22, This causes the movable cylinder 19 to move away from the passage 3 against the spring force of the spring 21. Displaced in the direction of When the fluid pressure in the discharge side passage 1 increases in this state, the valve body 24 It is pushed back against the spring force of the puller 21, and part of the oil in the discharge side passage 1 is drained. At this time, the air is released through the through hole 23 of the movable cylinder 19. is displaced by a predetermined amount in the direction away from the passage 3, so the spring 21 is compressed. The stroke until the annular groove 27 and the through hole 23 communicate with each other is longer than that in the case described above. also becomes larger. Therefore, the hydraulic pressure required to secure this stroke, that is, the Leaf pressure also increases.

[0031] In the embodiment described here, the pressure supplied to the working pressure chamber 22 is Although the liquid pressure in the discharge side passage 1 is used, another pressure supply means is connected to the pressure introduction passage 28. It is also possible to use it as

[0032]

[Effect of the idea]

As explained above, the device corresponding to claim 1 of the present invention has a valve body inside. Since the pressure adjustment means is connected to the back chamber side of the valve housing chamber, the back pressure of the valve body is controlled by the pressure adjustment means. The relief pressure can be increased or decreased by operating the A device corresponding to claim 2 includes a through hole that constantly communicates with the drain hole of the valve housing chamber. A movable cylinder is installed in the valve housing chamber to define an operating pressure chamber within the valve housing chamber. , a valve element biased by a spring in a direction to close the through hole is slid onto the movable cylinder; The interior is movable, and a pressure adjustment means is connected to the operating pressure chamber, making it possible to adjust the pressure. The position of the through-hole of the movable cylinder can be manipulated by changing the pressure introduced into the working pressure chamber using the adjusting device. By doing so, the relief pressure can be increased or decreased. Therefore, in any case Even when the pressure is off, the relief pressure can be adjusted with a very small operating force, making operation easier. It becomes possible to simplify and downsize the production section. It also reduces the burden on the operating section. Therefore, it is very advantageous in terms of component durability.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment corresponding to claim 1 of the present invention.

FIG. 2 is a sectional view showing the same embodiment.

FIG. 3 is a sectional view showing the same embodiment.

FIG. 4 is a sectional view showing another embodiment corresponding to claim 1 of the present invention.

FIG. 5 is a sectional view showing the same embodiment.

FIG. 6 is a sectional view showing an embodiment corresponding to claim 2 of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1...Discharge side passage, 2...Valve storage chamber, 2a...Back chamber, 4...Drain hole, 5...Valve body, 10...Pressure introduction path (pressure adjustment means), 12...Opening/closing valve (pressure adjustment means), 13... First drain hole (drain hole), 15...Check valve (pressure adjustment means), 17...Switching valve (pressure adjustment means), 19...Movable cylinder, 21...Spring, 22...Working pressure chamber, 23...
Through hole, 24...valve body, 28...pressure introduction path.

Claims (2)

[Scope of utility model registration request] Claim 1: A drain hole is provided in a valve accommodating chamber communicating with a discharge side passage of a pump circuit, and a valve body for opening and closing the drain hole is installed inside the valve body in a state in which the valve body is biased in the valve closing direction. An oil relief device that adjusts relief pressure by changing a biasing force, characterized in that a pressure adjustment means for adjusting the back pressure of the valve body is connected to a back chamber side of the valve housing chamber. Device. 2. A valve accommodating chamber having a valve accommodating chamber communicating with a discharge side passage of a pump circuit, a drain hole provided in the valve accommodating chamber, and a through hole constantly communicating with the drain hole; a movable cylinder that is slidably installed in the movable cylinder and defines an operating pressure chamber within the valve housing chamber; a valve body that is slidably installed in the movable cylinder and is biased by a spring in a direction to close the through hole; , a pressure adjusting means connected to the working pressure chamber to adjust the pressure in the working pressure chamber.