JP3337503B2 - Pressure regulator valve - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulator valve for controlling the discharge pressure of an oil pump as prescribed.

[0002]

2. Description of the Related Art A pressure regulator valve for adjusting the discharge pressure of an oil pump applies an oil pump discharge pressure as a feedback pressure to a spool thereof from one direction.
The configuration is such that as the hydraulic pressure increases, the drain amount of the oil pump discharge circuit increases due to the movement of the spool. Thus, when the oil pump discharge pressure increases, the drain amount increases and the oil pump discharge pressure decreases. Conversely, when the oil pump discharge pressure decreases too much, the drain amount decreases and the hydraulic pressure increases. As a result, the oil pump discharge pressure is controlled to a predetermined value. However, such a pressure regulator valve has a problem that the pressure regulation value fluctuates due to a so-called flow force. That is,
The greater the flow rate drained from the pressure regulator valve, the greater the flow rate through the clearance between the edge of the spool land and the wall of the valve body, and this flow causes the spool to have an orientation that opposes the force due to feedback pressure. Force acts. Therefore, as the flow rate of the oil pump discharge circuit increases, the pressure adjustment value of the pressure regulator valve increases. As a method of reducing the influence of the flow force, there is a method of compensating for an axial force acting on the spool. That is, by adjusting the shape of the spool, the oil that has passed through the clearance between the land of the spool and the wall of the valve body flows at a predetermined angle along the spool. Is generated to cancel the flow force in both directions (for example, see "Hydraulic Control", Mar. 20, 1988, September 20, 1981, 2nd edition, page 88).

[0003]

However, the method of compensating for the axial force acting on the spool as described above requires a gradual change in the oil flow along the spool. There is a problem that the dimension becomes long, and there is a practical difficulty in setting the shape of the spool for compensating the axial force, and there is a problem that the fluctuation of the pressure regulation value cannot always be reduced as desired. An object of the present invention is to solve such a problem.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by applying a negative suction pressure of an oil pump to a spool of a pressure regulator valve. That is,
According to the present invention, the discharge circuit (2) of the oil pump (20) is provided by feeding back the oil pump discharge pressure to act on the spool (12) of the pressure regulator valve.
As the oil pressure in 2) increases, the drain amount from the discharge circuit increases .
The discharge circuit (2) is increased through the pool valve land.
2) A pressure regulator valve (1) for adjusting the oil pressure as predetermined, wherein a pressure receiving portion (12e) for generating a force in a direction opposite to the feedback pressure when the oil pressure acts is provided on the spool (12). , This pressure receiving part (12
e) is connected to a suction circuit (32) in which the suction negative pressure of the oil pump (20) acts .
The numbers in parentheses indicate corresponding members in the embodiments described later.

[0005]

When the discharge amount of the oil pump increases, the flow rate discharged from the pressure regulator valve increases.
A force (flow force) for increasing the pressure adjustment value acts on the spool. However, when the discharge amount of the oil pump increases, the suction negative pressure increases. The negative suction pressure of the oil pump acts on the spool, and generates a force that decreases the pressure regulation value of the pressure regulator valve. Therefore,
The force for increasing the pressure adjustment value due to the discharge of the oil and the force for decreasing the pressure adjustment value due to the suction negative pressure of the oil pump are offset, and the pressure regulator valve adjusts the predetermined oil pressure. This prevents fluctuations in the pressure regulation value due to the flow rate of the oil pump.

[0006]

FIG. 1 shows a pressure regulator valve 1 according to a first embodiment of the present invention. A spool 12, a spring 14, and a sleeve 16 are fitted in a spool hole provided in the valve body 10. Sleeve 16
Are fixed to the valve body 10 by pins (not shown). The spool 12 is movable in the axial direction. The spool 12 has lands 12a, 12b, 12c and a shaft portion 12d. Lands 12b and 12c
Have the same diameter, but the land 12a has a smaller diameter than these. The shaft portion 12d is also smaller in diameter than the land 12b. The shaft portion 12 d fits with the inner diameter portion of the sleep 16. The valve body 10 is provided with only four grooves 10a, 10b, 10c and 10d. The groove 10a is provided with the hydraulic pressure supplied to the spool 1
It is configured to act on the end of the second land 12a. The groove 10 a is connected through an orifice 18 to a discharge circuit 22 connected to a discharge port of an oil pump 20. A separate plate 24 is provided on the upper surface of the valve body 10, and a predetermined hole is provided in the separate plate 24 so that each groove and the separate plate 24 are provided.
Another valve body (not shown) located above
The connection with the oil path is made. The groove 10b is a drain port from which oil is always discharged. The groove 10c is located between the lands 12b and 12c of the spool, and is a drain groove provided with an opening 26 on the lower side. Groove 10
d is provided at a position substantially corresponding to the land 12c of the spool 12. The groove 10d is connected to the discharge circuit 22 described above.
Is connected to A chamber 28 formed between the land 12c and the sleeve 16 (in which the spring 14 is disposed) is provided through an opening 30 provided on the lower side.
Suction circuit 3 connected to the suction port of oil pump 20
2 is connected. That is, a strainer 34 is attached to the lower surface of the valve pod 10, and a passage from the suction port 34a to the suction passage 10e of the valve body 10 is formed.
Is connected to The opening 26 of the groove 10c is also connected to the suction passage 10e. Suction passage 10e
Is connected to a suction circuit 32 connected to a suction port of the oil pump 20.

Next, the operation of this embodiment will be described. When the oil pump 20 is not operating, the spool 12 is pushed by the spring 14 and is in the state shown in the lower half in FIG. In this state, when the oil pump 20 starts to operate and outputs oil pressure to the discharge circuit 22, the oil pressure of the discharge circuit 22 acts on the groove 10a, and the spool 12 moves leftward in FIG. Move. As a result, the groove 10d which has been closed by the land 12c is brought into communication with the groove 10c. Thereby, the oil supplied from the discharge circuit 22 to the groove 10d is discharged to the groove 10c, and the discharged oil is discharged to the outside of the valve body 10 through the opening 26. The oil discharged from the opening 26 is mixed into the flow of the oil drawn from the suction port 34 a of the strainer 34 and flowing to the suction circuit 32. If the hydraulic pressure acting on the groove 10a becomes too high, the spool 1
2 compresses the spring 14 and moves further to the left, so that the amount of oil discharged from the groove 10d to the groove 10c increases. For this reason, the hydraulic pressure of the discharge circuit 22 decreases, and the spool 12 moves by the force of the spring 14 so that the clearance formed by the end of the land 12c becomes smaller between the groove 10d and the groove 10c. At the time of the pressure adjustment operation, a flow force is generated by oil flowing from the groove 10d to the groove 10c through the clearance. The flow force acts in a direction to push the spool 12 rightward in FIG. That is, it acts in a direction in which the oil pressure of the discharge circuit 22 regulated by the pressure regulator valve 1 increases. The flow force increases as the flow rate increases.
Therefore, the flow force for increasing the oil pressure of the discharge circuit 22 increases as the discharge flow rate of the oil pump 20 increases. Therefore, the oil pressure of the discharge circuit 22 does not become a desired constant value as it is. However, in this embodiment, the oil chamber 28
Is connected to the suction circuit 32 through the opening 30, so that the above-described problem does not occur. That is,
The oil chamber 28 is connected to the suction port of the oil pump 20, and the suction negative pressure of the oil pump 20 acts. Therefore, the annular pressure receiving portion 12 formed between the outer diameter of the land 12c of the spool 12 and the outer diameter of the shaft portion 12d.
e, the suction negative pressure of the oil pump 20 acts on the spool 1
2, a leftward force in FIG. The leftward force increases as the suction negative pressure of the oil pump 20 increases, that is, as the suction flow rate and the discharge flow rate of the oil pump 20 increase. The area of the pressure receiving portion 12e is set so that the leftward force in FIG. 1 due to the negative suction pressure of the oil pump 20 and the rightward force due to the above-described flow force match. Therefore, the flow force is always canceled out by the force due to the negative suction pressure of the oil pump 20, and no disturbance in the pressure adjustment value based on the flow force occurs. Thus, the pressure of the pressure regulator valve 1 can always be adjusted to a constant value corresponding to the spring 14.

FIG. 2 shows a second embodiment. In the second embodiment, the pressure regulator valve 2 suitable for the hydraulic control of the automatic transmission is provided by increasing the groove of the valve body 50 and the land of the spool 52. The spool 52 is composed of a first spool 52a, a second spool 52b, and a third spool 52c. However, since these operate integrally, they may be considered as one. The spool hole of the valve body 50 is closed by a plug 55. Further, the sleeve 56 is fixed to the valve body 50. The groove 50a is connected to the discharge circuit 22,
The groove 50b is a drain port, the groove 50c is connected to the oil passage 60 to which the hydraulic pressure adjusted by the solenoid for adjusting the hydraulic pressure at the same time as the shift is supplied, and the groove 50d is the oil supply for adjusting the hydraulic pressure. The groove 50e is connected to the discharge circuit 22, and the groove 50f
Is connected to an oil passage 62 connected to a torque converter, a groove 50g is connected to an oil passage 64 to which a pressure modifier pressure regulated by a solenoid is supplied, and a groove 50h is drained. I have. Groove 5
First, the oil of the discharge circuit 22 supplied to the outlet 50e is supplied to the first groove 50f.
Is discharged to The groove 50f is connected to an oil passage 62 that supplies oil pressure to a torque converter (not shown). If the flow rate increases so that the pressure cannot be adjusted due to the discharge of oil into the groove 50f, the spool 52 is moved to the position shown in FIG.
The oil moves further to the left, and the oil is discharged to the groove 50d. An oil chamber 68 formed between the first spool 50a and the second spool 50b is connected to the suction circuit 32 of the oil pump 20, as in the first embodiment. An annular pressure receiving portion is formed between the small diameter of the land of the first spool 52a and the outer diameter of the land of the second spool 52b. Thus, the force by the flow force can be canceled by the force by the suction negative pressure of the oil pump 20 as in the first embodiment, and the same operation as in the first embodiment can be obtained.

[0009]

As described above, according to the present invention, the negative pressure of the oil pump is applied to the spool of the pressure regulator valve so as to cancel the flow force. The force always cancels out, and a desired pressure regulation value can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of the present invention.

FIG. 2 is a diagram showing a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 pressure regulator valve 10 valve body 12 spool 12 e pressure receiving part 14 spring 20 oil pump 22 discharge circuit 28 oil chamber 32 suction circuit 34 strainer

Claims (1)

(57) [Claims] 1. A pressure regulator valve for adjusting the discharge pressure of the oil pump, by which is fed back to the oil pump discharge pressure to act on the spool of the pressure regulator valve, a discharge as hydraulic oil pump discharge circuit increases Spool valve for drain amount from circuit
A pressure receiving portion that generates a force opposing the feedback pressure when hydraulic pressure is applied, is provided on the spool. ,
A pressure regulator valve, wherein a suction circuit in which a suction negative pressure of an oil pump acts is connected to the pressure receiving portion.