JP2551975Y2 - Hydraulic control 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 hydraulic control valve having a housing and a valve member rotatably inserted into the housing.

[0002]

2. Description of the Related Art In a hydraulic power steering apparatus, for example, as shown in FIG. 10, a housing 101 and a valve member 102 rotatably inserted into the housing 101 are provided.
And a hydraulic control valve having the following.
The rotation of the valve member 102 according to the steering direction and the steering resistance supplies pressure oil to a hydraulic actuator for applying a steering assist force.

[0003] That is, the hydraulic control valve has an inlet port 103 communicating with the pump between the housing 101 and the valve member 102, a port 104 communicating with one oil chamber of a hydraulic actuator for applying a steering assist force, and the other. And a port 108 communicating with the tank. When steering left or right, pressure oil is supplied from the inlet port 103 to one oil chamber of the hydraulic actuator via one port 104, and the other port 105 communicates with the tank port 108. In the case of steering to the left or right, pressure oil is supplied from the inlet port 103 to the other oil chamber of the hydraulic actuator via the other port 105 and the one port 104
Is communicated with the tank port 108.

In such a hydraulic control valve, when pressure oil is supplied from the inlet port 103 via one port 104, the inlet port 103 and the one port 104 are connected to the other port 105 and the tank port 108.
In the case where pressure oil is supplied from the inlet port 103 through the other port 105, the inlet port 103 and the other port 105 are connected to the one port 104 and the tank port 108. Need to be prevented from communicating with Therefore, circumferential grooves 113, 114, 115, and 116 are formed between the ports 103, 104, 105, and 108 on the outer periphery of the valve member 102,
Seal rings 109, 110, 111, 112 are fitted into the circumferential grooves 113, 114, 115, 116.
The oil pressure between the housing 101 and the valve member 102 acts on the seal rings 109, 110, 111, 112 according to the steering direction, so that the seal rings 109, 11
0, 111, and 112 are pressed against the inner peripheral surface of the housing 101 and one side surface of the peripheral grooves 113, 114, 115, and 116, and pressure oil leaks through a gap between the inner and outer peripheral surfaces of the housing 101 and the valve member 102. Has been prevented.

[0005] That is, when steering in one direction to the left and right, as shown in FIG. 11, the uppermost seal ring 109 and the third seal ring 109 from the top in FIG.
01 and one side surface of the circumferential grooves 113 and 115. In the case of steering in the other direction to the right and left, as shown in FIG.
112 is pressed against the inner peripheral surface of the housing 101 and one side surface of the peripheral grooves 114 and 116 by the hydraulic pressure P.

[0006]

SUMMARY OF THE INVENTION A seal ring 109, 1 interposed between a housing 101 and a valve member 102.
In a state where no hydraulic pressure is applied, 10, 111 and 112 have a slight gap with respect to the inner peripheral surface of the housing 101 and the inner surfaces of the peripheral grooves 113, 114, 115 and 116 as shown in FIG. ing. Further, as shown in FIG. 14, the oil pressure between the inner and outer circumferences of the housing 101 and the valve member 102 acts as shown by arrows in the figure, so that the seal rings 109, 110, 111, 112 101a and circumferential grooves 113, 11
4, 115, 116, one side surface 113a, 114a, 11
5a, 116a to seal between the inner peripheral surface 101a of the housing 101 and the inner peripheral surface 102a of the valve member 102.

However, the seal rings 109, 110, 1
The outer peripheral surfaces of 11, 11 are the inner peripheral surface 10 of the housing 101.
When worn due to friction with 1a, as shown in FIG.
Inner peripheral surface 101a of housing 101 and seal ring 10
Since the gap between the outer peripheral surface of each of the seal rings 109, 110, 111, and 112 becomes large, the seal rings 109, 110, 111, and
Reference numeral 112 denotes the inner peripheral surface 101a of the housing 101 and the peripheral groove 11
One side 113a, 114 of 3, 114, 115, 116
a, 115a, 116a cannot be pressed against
There is a problem that the pressurized oil leaks into the tank as shown by the arrow in the figure and it is not possible to provide the steering assist force.

An object of the present invention is to provide a hydraulic control valve capable of solving the above-mentioned problems of the prior art.

[0009]

SUMMARY OF THE INVENTION The present invention is characterized in that it comprises a housing and a valve member rotatably inserted into the housing, and a peripheral groove is formed on the outer periphery of the valve member. Hydraulic control in which a seal ring is fitted into the groove, and the seal ring is pressed against the inner peripheral surface of the housing and one side surface of the peripheral groove by applying a hydraulic pressure between the inner and outer circumferences of the housing and the valve member to the seal ring. In the valve, the height from the bottom surface of the opposite side surface of the peripheral groove is lower on one side surface than on the other side surface.

[0010]

According to the structure of the present invention, the height of the opposite side surface of the peripheral groove from the bottom surface is made lower on one side than on the other side, so that the area of the end surface of the seal ring exposed from the peripheral groove is reduced. It is larger on the side facing the other side than on the side facing the one side of the circumferential groove. Since the seal ring is pressed against one side surface of the circumferential groove by hydraulic pressure acting on the end surface on the side opposite to the other side surface of the circumferential groove, compared with the case where the heights of the opposite side surfaces of the circumferential groove from the bottom surface are equal. The seal ring is securely pressed against one side surface of the circumferential groove. Since hydraulic pressure acts on the inner peripheral surface of the seal ring pressed against one side surface of the peripheral groove, the seal ring is pressed against the outer peripheral surface of the housing.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

A rack and pinion type hydraulic power steering device 1 shown in FIG. 4 has an input shaft 2 connected to a steering wheel (not shown) of a vehicle, and a torsion bar 6 connected to the input shaft 2.
And an output shaft 3 connected thereto via the The torsion bar 6 is connected to the input shaft 2 via a pin 4 and connected to the output shaft 3 via a serration 5. The input shaft 2 is rotatably supported inside the valve housing 7 via a bearing 8 and inside the output shaft 3 via a bush 12. The output shaft 3 is rotatably supported inside the rack housing 9 via bearings 10 and 11. A pinion 15 is formed integrally with the output shaft 3, and a steering wheel (not shown) is connected to a rack 16 that meshes with the pinion 15. Thus, the rotation of the input shaft 2 due to the steering operation input is controlled by the torsion bar 6.
Is transmitted to the pinion 15 integrated with the output shaft 3 via the shaft, and the rotation of the pinion 15 causes the rack 16 to move in the vehicle width direction to steer the vehicle.

A support yoke 40 and a spring 41 are inserted into an insertion hole 9a formed in the rack housing 9 for smoothing the meshing state between the pinion 15 and the rack 16.
The insertion hole 9a is closed by screwing the adjusting member 42. The support yoke 40 is movable in the left-right direction in FIG. 4 and presses the rack 16 against the pinion 15 by the elastic force of the spring 41. The pressing force can be adjusted by adjusting the amount of screwing of the adjusting member 42 into the rack housing 9.

A hydraulic cylinder 20 is provided as a hydraulic actuator for applying a steering operation assisting force. The hydraulic cylinder 20 includes a cylinder tube configured by the rack housing 9 and a piston 21 integrated with the rack 16. In order to supply pressure oil to the oil chambers 22 and 23 in the cylinder tube partitioned by the piston 21 in accordance with the steering direction and the steering resistance, the pressure oil is supplied to the outer periphery of the input shaft 2 according to the torsion angle of the torsion bar 6. A hydraulic control valve 30 is provided which operates.

The control valve 30 has a cylindrical valve member 31 which is inserted into the valve housing 7 so as to be relatively rotatable and surrounds the input shaft 2. The valve member 31 is connected to the output shaft 3 via a pin 32 so as to rotate together therewith. An inlet port 34 connected to a pump 33 and an outlet port 36 connected to a tank 35 are provided between the valve member 31 and the valve housing 17.
And a first port 37 connected to one oil chamber 22 of the hydraulic cylinder 20 and a second port 38 connected to the other oil chamber 23. Each port 34, 36, 3
Reference numerals 7 and 38 communicate with each other through a flow path between the input shaft 2 and the valve member 31, and the degree of opening of the flow path is adjusted by the relative rotation between the input shaft 2 and the valve member 31 due to the torsion of the torsion bar 6. Is done.

That is, as shown in FIG.
In the inner periphery of the shaft, concave portions 50 are formed along the axial direction at eight circumferentially equal intervals, and the input shaft 2 facing the concave portion 50 is formed.
Are formed on the outer periphery of the. The recess 50 is
The one communicating with the first port 37 via the flow path 53 and the one communicating with the second port 38 via the flow path 54 are alternately arranged in the circumferential direction. Further, a portion of the recess 50 in the circumferential direction includes a portion communicating with the inlet port 34 via the flow path 55, the flow path 52, the torsion bar 6, and the input shaft 2.
And a portion communicating with the tank port 36 through the inner and outer circumferences thereof are alternately arranged in the circumferential direction. Thus, when steering is not performed, as shown in FIG.
And the tank port 36 communicate with each other, and no pressure oil is supplied to the oil chambers 22 and 23 of the hydraulic cylinder 20.

When the torsion bar is twisted by steering resistance caused by steering to the left or right and the valve member 31 and the input shaft 2 rotate relative to each other, the relative positions of the concave portion 50 and the convex portion 51 change. Due to this relative position change, the valve member 3
The opening degree of the oil passage from the inlet port 34 to the first port 37 between the first port 37 and the input shaft 2 increases, and the oil passage from the first port 37 to the tank port 36 decreases. The degree of opening of the oil passage to the second port 38 is reduced, and the tank port 3
The degree of opening of the oil passage to 6 increases. As a result, pressure oil having a pressure corresponding to the steering direction and the steering resistance is supplied to one oil chamber 22 of the hydraulic cylinder 20, and the oil flows back to the tank 35 from the other oil chamber 23 and to one of the left and right sides of the vehicle. The steering assist force acts on the rack 16 from the hydraulic cylinder 20. When the steering is performed to the left or right, the valve member 31 and the input shaft 2 relatively rotate in a direction opposite to that in the case where the steering is performed to the left or right, the opening degree of the oil passage from the inlet port 34 to the second port 38 increases, and the second The opening of the oil passage from the port 38 to the tank port 36 is reduced, and the opening of the oil passage from the inlet port 34 to the first port 37 is reduced, and the oil passage from the first port 37 to the tank port 36 is reduced. The degree of opening increases. As a result, the steering assist force to the left and right sides of the vehicle is
Act on the rack 16.

The valve housing 7 and the valve member 31
In order to prevent pressure oil from leaking into the tank port 36 from between the inner and outer circumferences of the valve housing 7 as shown in FIG.
Four seal rings 60 between the inner and outer circumferences of the
61, 62 and 63 are interposed. That is, each port 34, 36, 37, 38 is arranged along the axial direction,
The inlet port 3 is located between the first port 37 and the second port 38 between the inner and outer circumferences of the valve housing 7 and the valve member 31.
The outlet port 36 is disposed above the valve member 31. Then, the upper part of the first port 37 and the first
Between the port 37 and the inlet port 34;
Seal rings 60, 61, 62, 63 are arranged between and below the second port 38 and below the second port 38.
Each seal ring 60, 61, 62, 63 is provided with a valve member 31.
Are fitted in peripheral grooves 64, 65, 66, 67 formed on the outer periphery of the.

Pressure oil is supplied from the inlet port 34 to the first port 37.
When the oil is supplied to one of the oil chambers 22 of the hydraulic cylinder 20 through the seal ring 60 between the uppermost seal ring 60 and the third seal ring 62 from the top in FIG. The hydraulic pressure between the inner and outer circumferences increases.
As shown in FIG. 2, the uppermost seal ring 60 is pressed against the upper side surface 64a of the circumferential groove 64 and the inner peripheral surface 7a of the valve housing 7 by this hydraulic pressure P, as shown in FIG. The seal ring 62 is pressed against the lower side surface 64 a of the circumferential groove 66 in the figure and the inner peripheral surface 7 a of the valve housing 7. In addition, the second port 3
When the pressure oil is supplied to the hydraulic cylinder 20 through the seal ring 8, the valve housing 7 is disposed between the second seal ring 61 from the top and the seal ring 63 at the bottom in the figure.
The hydraulic pressure between the inner and outer circumferences of the valve member 31 and the valve member 31 increases. As shown in FIG. 3, the second seal ring 61 from above is pressed against the upper side surface 65a of the circumferential groove 65 and the inner peripheral surface of the valve housing 7 by the hydraulic pressure P, as shown in FIG. The seal ring 63 is provided on the lower side surface 6 of the circumferential groove 67 in the figure.
7a and the inner peripheral surface 7a of the valve housing 7. Accordingly, when the steering is performed to supply the hydraulic oil to the hydraulic cylinder 20, the hydraulic oil is supplied to the valve housing 7.
Leakage between the inner and outer peripheries of the valve member 31 and the tank port 36 is prevented.

As shown in FIG. 6, the outer diameter of the valve member 31 is made different on one side and the other side of each of the circumferential grooves 64, 65, 66, 67.
Bottom surfaces 64c, 65 of opposing side surfaces of 5, 66, 67
c, 66c, 67c, the height from the seal ring 60,
One side 6 on which 61, 62 and 63 are pressed by hydraulic pressure
The height H at the other side surface 64b, 65b, 66b, 67b is higher than the height H1 at 4a, 65a, 66a, 67a.
2 is lower.

According to the above configuration, each of the circumferential grooves 64, 65, 6
Seal rings 60, 61, 62 exposed from 6, 67;
The area of the end face of 63 is one side face 64a, 65a, 6 of the circumferential groove.
The area S2 on the side opposite to the other side surfaces 64b, 65b, 66b, 67b than the area S1 on the side opposite to 6a, 67a.
Is made larger. Other side surfaces 64b, 65 of the circumferential groove
As shown in FIG. 7, the seal rings 60, 61, 62, and 63 are caused to have one side surface 64a, 65a, and 66 of the circumferential groove by hydraulic pressure indicated by an arrow acting on the side facing the b, 66b, and 67b.
a, 67a, so that the pressing is more reliably performed as compared with the case where the height of the peripheral side surface from the bottom surface of the opposite side surface is equal. And one side surface 64a, 65a, 6 of the circumferential groove
6a, 67a, sealing rings pressed against 67a
Since the hydraulic pressure acts on the inner peripheral surfaces of 1, 62 and 63 as indicated by arrows in the figure, the seal rings 60 and 6 shown in FIG.
1, 62, 63 are surely the inner peripheral surface 7 of the valve housing 7.
a. Thereby, the seal ring 60,
Even if the outer peripheral surfaces of 61, 62, and 63 are worn by friction with the inner peripheral surface 7a of the valve housing 7, the sealing effect can be reliably achieved for a long period of time.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the outer diameter of the valve member 31 is made different between one side and the other side of the circumferential grooves 64, 65, 66, 67, so that the side faces of the circumferential grooves 64, 65, 66, 67 facing each other. Height from the bottom of the
As shown in FIG. 9, by forming a chamfered portion 70 on the radial outside of the other side surface of the circumferential grooves 64, 65, 66, 67,
The height from the bottom surface may be lower on one side than on the other.

In the above embodiment, the present invention is applied to the hydraulic control valve of the rack and pinion type hydraulic power steering device. However, the present invention can be applied to the hydraulic control valve of the ball screw type hydraulic power steering device. In short, a housing and a valve member rotatably inserted into the housing are provided, a circumferential groove is formed on the outer periphery of the valve member, a seal ring is fitted into the circumferential groove, and the housing is The present invention can be applied to any hydraulic control valve in which the seal ring is pressed against the inner peripheral surface of the housing and one side surface of the peripheral groove by the action of the hydraulic pressure between the inner and outer periphery of the valve member.

[0024]

According to the hydraulic control valve according to the present invention, even if the outer peripheral surface of the seal ring is worn, the seal between the inner and outer peripheries of the valve member and the housing can be reliably performed, and can be surely performed for a long time. A hydraulic control function can be performed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a hydraulic control valve according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating the operation of the hydraulic control valve according to the embodiment of the present invention.

FIG. 3 is a diagram illustrating the operation of the hydraulic control valve according to the embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of the hydraulic power steering device according to the embodiment of the present invention.

FIG. 5 is a cross-sectional view of the hydraulic control valve according to the embodiment of the present invention;

FIG. 6 is a diagram illustrating the operation of the hydraulic control valve according to the embodiment of the present invention.

FIG. 7 is a diagram illustrating the operation of the hydraulic control valve according to the embodiment of the present invention.

FIG. 8 is a diagram illustrating the operation of the hydraulic control valve according to the embodiment of the present invention.

FIG. 9 is a configuration explanatory view of a hydraulic control valve according to a different embodiment.

FIG. 10 is a sectional view of a hydraulic control valve according to a conventional example.

FIG. 11 is a diagram illustrating the operation of a hydraulic control valve according to a conventional example.

FIG. 12 is a diagram illustrating the operation of a hydraulic control valve according to a conventional example.

FIG. 13 is a diagram illustrating the operation of a hydraulic control valve according to a conventional example.

FIG. 14 is a diagram illustrating the operation of a hydraulic control valve according to a conventional example.

FIG. 15 is an explanatory view showing a problem of a hydraulic control valve according to a conventional example.

[Explanation of symbols]

 7 Valve housing 7a Inner peripheral surface 31 Valve member 60, 61, 62, 63 Seal ring 64, 65, 66, 67 Circumferential groove 64a, 65a, 66a, 67a One side 64b, 65b, 66b, 67b Other side 64c, 65c, 66c, 67c Bottom

Claims (1)

(57) [Scope of request for utility model registration] 1. A housing comprising: a housing; and a valve member rotatably inserted into the housing. A peripheral groove is formed on an outer periphery of the valve member, and a seal ring is fitted into the peripheral groove. In the hydraulic control valve in which the seal ring is pressed against the inner peripheral surface of the housing and one side surface of the peripheral groove by the action of hydraulic pressure between the inner and outer periphery of the housing and the valve member, the bottom surface of the opposing side surface of the peripheral groove is provided. The hydraulic control valve is characterized in that the height from the lower side is lower on one side than on the other.