JPH092307A - Hydraulic power-steering device - Google Patents

Abstract

PURPOSE: To eliminate the need for a bearing for supporting an input shaft to reduce the number of parts and simplify the manufacturing process by pressing an output shaft into the inner periphery on an axial end side of the first valve member, supporting the input shaft by the inner periphery of the first valve member, and closing an axial end side of a recessed part of the first valve member. CONSTITUTION: An output shaft 4 is connected through a torsion bar 3 to an input shaft 2 connected to the steering handle. The peripheral wall part 4a on one end side of the output shaft 4 is coaxially pressed into the inner periphery on an axial end side of the first cylindrical valve member 24, and the first valve member 24 is rotated in company with the output shaft 4. The input shaft 2 is coaxially and relatively rotatably supported in the inner periphery of the first valve member 24. The second valve member 25 is relatively rotatably inserted into the first valve member 24 to be rotated in company with the input shaft 2. Thus, the need for a bearing for supporting the input shaft 2 is eliminated to reduce the number of parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic power steering system having a rotary hydraulic control valve.

[0002]

2. Description of the Related Art A conventional rack and pinion type hydraulic power steering apparatus 101 shown in FIG.
And an output shaft 104 connected to the input shaft 102 via a torsion bar 103. The torsion bar 1003 is inserted into the inner peripheral hole 102a of the input shaft 102, and one end thereof is serrated 106.
Is connected to the output shaft 104 via the
Is connected to the input shaft 102 via a pin 105 press-fitted into the torsion bar 103. A pinion 107 is formed on the output shaft 104, and a rack 108 meshing with the pinion 107 is connected to a steering wheel (not shown). The outer circumference of the input shaft 102 is the bearing 109 and the bearing 1.
It is supported by the valve housing 110 a via 11. The output shaft 104 is supported by the rack housing 110b via bearings 112 and 113. Its input shaft 2
Is transmitted to the pinion 107 via the torsion bar 103 to move the rack 8 in the vehicle width direction,
The wheels are steered by the movement of the rack 108.

A hydraulic cylinder 118 is provided as a hydraulic actuator that applies a steering assist force. The hydraulic cylinder 118 includes a cylinder tube constituted by a rack housing 110b and a piston 120 integrally formed with the rack 108.
A pair of oil chambers 121 and 122 that are partitioned by is formed. A rotary hydraulic control valve 123 is connected to each oil chamber 121, 122. The control valve 123 includes a tubular first valve member 124. The first valve member 124 is connected to the output shaft 104 via the pin 126, and thus rotates together with the output shaft 104. The second valve member 125 is inserted into the first valve member 124 so as to be relatively rotatable. The second valve member 125 is the input shaft 1.
By being integrally formed on the outer periphery of 02, the input shaft 102 rotates together with the input shaft 102. The first valve member 124 has a tubular main body portion 124a and a pair of annular portions 124b and 124c which are press-fitted at both inner peripheral ends of the main body portion 124a.

A plurality of recesses 12 along the axial direction are formed on the inner circumference of the first valve member 124 and the outer circumference of the second valve member 125.
4'and 125 'are formed at intervals in the circumferential direction. The opening degree between the edge of the first valve member side recess 124 'along the axial direction and the edge of the second valve member side recess 125' along the axial direction changes due to the relative rotation of both valve members 124, 125. The throttles are arranged in oil passages that connect the oil chambers 121 and 122 of the hydraulic cylinder 118, the pump 137, and the tank 141. The relative rotation of the valve members 124 and 125 due to the torsion of the torsion bar 103 according to the steering resistance and the steering direction changes the opening degree of each throttle portion, and the hydraulic pressure acting on the hydraulic cylinder 118 is controlled to control the steering. A steering assist force corresponding to the resistance and the steering direction is applied.

The above conventional hydraulic power steering system 1
01, the first valve member 124 and the output shaft 104
Are connected together by a pin 126 so as to be rotatable together, but the radial movement of the first valve member 124 is not restricted. Therefore, when the input shaft 102 swings in the radial direction,
The first valve member 124 is pressed against the valve housing 110a by the input shaft 102, causing malfunction. In order to prevent such a malfunction, the input shaft 1
The outer periphery of 02 is connected to the valve housing 11 via a bearing 109.
It is supported by the inner circumference of the output shaft 104 via the bearing 111, and is supported by the inner circumference of the output shaft 104.

However, since bearings 109 and 111 for supporting the outer circumference of the input shaft 102 are required, there is a problem that the number of parts and the number of assembling steps increase.

Therefore, the output shaft is press-fitted into the inner periphery of the first valve member on the one end side in the axial direction to restrict the radial movement of the first valve member, and the input is made by the inner periphery of the first valve member. A configuration for supporting a shaft is disclosed (US Pat.
489755).

[0008]

In the structure disclosed in the above-mentioned US Patent, the first valve member is press-fitted with the output shaft after the recessed portions having both ends closed are formed on the inner periphery thereof. . However, the U.S. patent publication does not disclose any means for forming a recess in the inner circumference of the first valve member.

Conventionally, in order to form a recess having both ends closed on the inner circumference of the first valve member, as shown in FIG.
First, a concave portion having open ends is formed in the cylindrical main body portion 124a by machining such as a broach, and after that,
A pair of annular parts 124 are provided at both ends of the inner circumference of the body part 124a.
b and 124c were press-fitted to close both ends of the recess.
Therefore, the body portion 124a and the pair of annular portions 124b, 1
There is a problem that at least three parts of 24c are necessary and the number of parts is increased. In order to eliminate the need for such an annular portion, it has been proposed to form a closed recess at both ends on the inner circumference of the first valve member by cold forging. However, both ends of the recess are closed. Requires a complicated molding process.

Further, in the configuration disclosed in the above-mentioned US patent publication, since the input shaft and the output shaft are not connected via the torsion bar, a retaining mechanism for both is required, and the configuration is complicated. become.

It has also been found that when the output shaft is press-fitted into the inner periphery of the first valve member on the one end side in the axial direction, if the input shaft and the output shaft are connected by a torsion bar as in the conventional case, a malfunction occurs. .

That is, in the structure shown in FIG. 15, one end of the torsion bar 103, which is press-fitted into the output shaft 104 via the serration 106, has a cylindrical shape. Therefore, at the connecting position between the one end of the torsion bar 103 and the input shaft 102 via the serration 106 and at the connecting position between the other end of the torsion bar 103 and the input shaft 102 via the pin 105, the axial center of the torsion bar 103 is set in the radial direction. Cannot be displaced. Then, since the torsion bar 103 has a bend due to processing tolerance, the axis of the torsion bar 103 is deviated from the axis of the output shaft 102, and the axis of the input shaft 102 connected to the torsion bar 103 is also output. It will deviate from the axis of the shaft 104. Conventionally, since the input shaft 102 is supported via bearings 109 and 111, even if the axis of the input shaft 102 deviates from the axis of the output shaft 4, the input shaft 102 and the first valve member 124 are separated from each other. I was able to smoothly rotate the relative.

However, the input shaft 102 is connected to the first valve member 1
When the shaft is supported by the inner circumference of the shaft 24, as compared with the case where the shafts are supported by the bearings 109 and 111, when the axis of the input shaft 102 deviates from the shaft of the output shaft 104 due to the bending of the torsion bar 103, The frictional resistance that prevents relative rotation with the 1-valve member 124 increases. for that reason,
The control of the hydraulic pressure acting on the steering assist force generating hydraulic cylinder 118 is hindered, and malfunction occurs.

It is an object of the present invention to provide a hydraulic power steering system that can solve the above problems.

[0015]

SUMMARY OF THE INVENTION The present invention is directed to an input shaft that is rotated by steering, an output shaft that is connected to the input shaft via a torsion bar, and a cylindrical first valve member that rotates together with the output shaft. And a second rotating shaft that rotates with the input shaft.
A valve member, the second valve member is rotatably inserted into the first valve member, and a plurality of recesses along the axial direction are formed around the inner circumference of the first valve member and the outer circumference of the second valve member. Between the edges along the axial direction of the first valve member side concave portion and the edges along the axial direction of the second valve member side concave portion, the opening degree changes due to relative rotation of both valve members. In a control valve for a hydraulic power steering device in which a hydraulic pressure acting on a hydraulic actuator for generating a steering assist force is controlled by a change in the opening degree of the throttle part, an inner side of one end of the first valve member in the axial direction is controlled. The output shaft is press-fitted coaxially around the circumference, and the input shaft is supported by the inner circumference of the first valve member so as to be rotatable relative to the coaxial center. One end side in the axial direction of the concave portion of the inner circumference of the first valve member is output. Closed by a shaft And wherein the door.

At least one of the connection position between the one end of the torsion bar and the output shaft and the connection position between the other end of the torsion bar and the input shaft, the shaft of the torsion bar before the connection between the torsion bar and the input shaft. One end of the torsion bar is preferably connected to the output shaft so that radial displacement of the core is allowed.

[0017]

According to the structure of the present invention, the first
Since the output shaft is press-fitted into the inner circumference of the valve member on the one end side in the axial direction and the input shaft is supported by the inner circumference of the first valve member, a bearing for supporting the input shaft is unnecessary, and the number of parts can be reduced. At this time, by closing one end side in the axial direction of the recess on the inner circumference of the first valve member by the output shaft, when machining the recess by using a broach or the like, one end side in the axial direction of the recess is closed. It is possible to reduce the number of parts by omitting the parts to be formed, and when forming the recess by forging, it is not necessary to close both ends in the axial direction of the recess, so that the forming process can be simplified.

At least one of the connection position between the one end of the torsion bar and the output shaft and the connection position between the other end of the torsion bar and the input shaft, before the connection between the torsion bar and the input shaft, the shaft of the torsion bar is connected. By displacing the core in the radial direction according to the bending of the torsion bar, the axis of the torsion bar can be displaced toward the axis of the output shaft. As a result, the deviation of the axis of the input shaft connected to the torsion bar from the axis of the output shaft can be reduced, and even when the input shaft is supported by the inner circumference of the first valve member, the input shaft and the first valve are not supported. Friction resistance between the member and the member does not increase, and malfunctions can be prevented.

[0019]

Embodiments of the present invention will be described below with reference to the drawings.

A rack and pinion type hydraulic power steering system 1 shown in FIG. 1 has an input shaft 2 connected to a steering handle (not shown) and a torsion bar 3 attached to the input shaft 2.
And an output shaft 4 which is connected via. The torsion bar 3 is inserted into the inner peripheral hole 2a of the input shaft 2, one end of which is connected to the output shaft 4 through serrations 6, and the other end of which is a pin 5 which is press-fitted into the input shaft 2 and the torsion bar 3. It is connected to the input shaft 2 via. A helical pinion 7 is formed on the output shaft 4, and a helical rack 8 meshing with the pinion 7 is connected to a steering wheel (not shown). The output shaft 4 is supported by the housing 10 via bearings 12 and 13. The rotation by the steering of the input shaft 2 is transmitted to the pinion 7 via the torsion bar 3 to move the rack 8 in the vehicle width direction, and the wheels are steered by the movement of the rack 8.

A hydraulic cylinder 18 is provided as a hydraulic actuator that applies a steering assist force. The hydraulic cylinder 18 includes a cylinder tube formed by the housing 10 and a piston 2 formed integrally with the rack 8.
And a pair of oil chambers 21 and 22 partitioned by the piston 20 are formed. A rotary hydraulic control valve 23 is connected to each of the oil chambers 21 and 22.

The control valve 23 has a tubular first valve member 24. The first valve member 24 is rotatably inserted in the housing 10 via a seal member 29. A peripheral wall portion 4a at one end of the output shaft 4 is coaxially press-fitted to the inner periphery of the first valve member 24 on the one end side in the axial direction. As a result, the first valve member 24 and the output shaft 4 rotate together. The input shaft 2 is supported by the inner circumference of the first valve member 24 so as to be rotatable relative to the coaxial center. The outer periphery of the input shaft 2 is a second valve member 25,
As a result, the second valve member 25 is inserted into the first valve member 24 so as to be relatively rotatable, and rotates together with the input shaft 2. The oil seal 4 is provided between the housing 10 and the input / output shafts 2 and 4 above and below the first valve member 24.
6, 47 are provided.

As shown in FIG. 2, on the inner circumference of the first valve member 24 and the outer circumference of the second valve member 25, a plurality of recesses along the axial direction are formed at equal intervals in the circumferential direction. The first valve member-side recesses are three right steering recesses R located at equal circumferential intervals, and the three right steering recessed portions are located at equal circumferential intervals.
And two left steering recesses L. The second valve member side recesses are composed of three pressure oil supply recesses P which are located at equal circumferential intervals, and three pressure oil discharge recesses T which are located circumferentially at equal intervals. Each right steering recess R and each left steering recess L are alternately arranged in the circumferential direction, and each pressure oil supply recess P and each pressure oil discharge recess T are alternately arranged in the circumferential direction.

As shown in FIGS. 1 and 2, each of the right steering recesses R has a passage 31 formed in the first valve member 24 and a right steering port 32 formed in the housing 10,
It communicates with one oil chamber 21 of the hydraulic cylinder 18. Each of the left steering recesses L has a flow path 33 formed in the first valve member 24.
And the left steering port 34 formed in the housing 10 to communicate with the other oil chamber 22 of the hydraulic cylinder 18. Each pressure oil supply recess P has a flow path 35 formed in the first valve member 24 and an inlet port 36 formed in the housing 10.
To the pump 37 via. Each pressure oil discharge recess T
Is an extension recess 3 formed on the outer periphery of the second valve member 25.
8 and the outlet port 40 formed in the housing 10 to the tank 41. As a result, the pump 3
7, tank 41, and oil chambers 21 of hydraulic cylinder 18,
22 communicates with each other via an inter-valve flow path between the inner and outer circumferences of the first valve member 24 and the second valve member 25.

As shown in FIG. 2, in the inter-valve flow path, both valve members are provided between the edge of the first valve member side concave portion along the axial direction and the edge of the second valve member side concave portion along the axial direction. A throttle portion A whose opening degree changes by relative rotation of 24 and 25,
B, C, and D. As shown below, both valve members 2
4, 25 are rotated relative to each other by the torsion of the torsion bar 3 depending on the steering resistance and the steering direction, so that the throttle portions A,
The opening degrees of B, C, and D are changed, the hydraulic pressure acting on the hydraulic cylinder 18 is controlled, and the steering assist force according to the steering resistance and the steering direction is applied.

FIG. 2 shows the relative positions of the two valve members 24, 25 in a non-steered state. In this state, the pressure oil supply recesses P and the pressure oil discharge recesses T are all throttles. Since they communicate with each other through the parts A, B, C, D, the pressure oil supplied from the pump 37 directly flows back to the tank 41, and no steering assist force is generated. When the steering wheel is steered to the right from a state in which the steering assist force is not generated, the torsion bar 3 is twisted in accordance with the steering resistance applied to the wheels from the road surface, and the two valve members 24 and 25 relatively rotate. As a result, the opening of the throttle portion A between each right steering recess R and each pressure oil supply recess P and the throttle portion B between each left steering recess L and each pressure oil discharge recess T are reduced. The opening degree becomes large, and the opening degree of the throttle portion C between each right steering recess portion R and each pressure oil discharge recess portion T and the throttle portion between each left steering recess portion L and each pressure oil supply recess portion P are increased. The opening degree of the portion D becomes smaller. As a result, the pressure oil is supplied from the pump 37 to the one oil chamber 21 of the hydraulic cylinder 18, the pressure oil is circulated from the other oil chamber 22 of the hydraulic cylinder 18 to the tank 41, and the steering assist force to the right of the vehicle is provided. Acts on the rack 8 according to the steering resistance. Further, when the steering is performed to the left from a state in which no steering assist force is generated, the opening of each of the throttle portions A, B, C, and D changes in reverse to the case where the steering is performed to the right. The auxiliary force acts on the rack 8 according to the steering resistance.

As shown in FIG. 3, the first valve member 24 has a tubular main body portion 24a and an annular portion 24b which is press-fitted into the inner circumference of the other end side of the main body portion 24a. The recess R along the axial direction of the inner circumference of the first valve member 24,
In order to form L, first, the inner periphery of the cylindrical main body portion 24a is machined by a broach or the like to form open recesses on both axial ends, and then the annular portion is formed on the main body portion 24a. The other end of the recess in the axial direction is closed by press-fitting 24b, and then the output shaft 4 is press-fitted into the inner circumference of the one end of the main body 24a, so that the one end of the recess in the axial direction is closed. It is closed.

As a result, the output shaft 4 is press-fitted into the inner circumference of the first valve member 24 on the one end side in the axial direction, and the input shaft 2 is supported by the inner circumference of the first valve member 24, thereby supporting the input shaft 2. The number of parts can be reduced by eliminating the need for bearings.
At this time, when one end side of the recesses R, L on the inner circumference of the first valve member 24 in the axial direction is closed by the output shaft 4, the recesses R, L are machined using a broach or the like. A component for closing one end side of the recesses R, L in the axial direction is unnecessary, and the number of components can be reduced.

Further, one end of the torsion bar 3 which is press-fitted into the output shaft 4 through the serration 6 has a spherical portion 3a, and the other end has a cylindrical portion 3a '. Prior to press-fitting the spherical portion 3a at one end of the torsion bar 3 into the output shaft 4, the output shaft 4 is press-fitted into the inner periphery of the first valve member 24 on the one end side in the axial direction, and the axial center of the first valve member 24 is pressed. And the axis of the output shaft 4 are matched. Then, the spherical portion 3a at one end of the torsion bar 3 is pressed into the output shaft 4. This press-fitting is performed by the cylindrical portion 3 at the other end of the torsion bar 3.
The outer periphery of the cylindrical portion 3a 'is guided while being guided by an unillustrated assembly jig so that the axis of a'is aligned with the axis of the output shaft 4. When the torsion bar 3 is bent by the guide, the axis of the torsion bar 3 is displaced in a direction coinciding with the axis of the output shaft 4 according to the bending, and one end of the torsion bar 3 has a spherical portion 3a. Therefore, it is press-fitted onto the output shaft 4 while allowing the displacement. Thereafter, the torsion bar 3 is inserted into the inner peripheral hole 2a of the input shaft 2, the input shaft 2 is inserted into the inner periphery of the first valve member 24, and the input shaft 2 and the torsion bar 3 are connected by the pin 5. .

The alternate long and short dash line in FIG. 3 exemplifies the positions when the displacement of the axial center 3o of the torsion bar 3 is not allowed and when it is allowed.

As a result, it is possible to reduce the radial deviation of the shaft center of the input shaft 2 connected to the torsion bar 3 from the shaft center of the output shaft 4, so that the input shaft 2 can be moved by the inner circumference of the first valve member 24. Even when supported, the input shaft 2 and the first valve member 2
The frictional resistance with 4 does not increase, and malfunctions can be prevented.

As shown in FIG. 1, a seal member 49 is interposed between the cylindrical portion 3a 'at the other end of the torsion bar 3 and the input shaft 2.

As shown in FIG. 4, when the cylindrical cap 51 screwed into the housing 10 is brought into contact with the outer ring of the bearing 13 that supports the end portion side of the output shaft 4, the bearing 1
3 is prevented from coming off from the housing 10. In addition, one end face of a C-shaped retaining ring 52 made of an elastic material, which is fitted into the circumferential groove 4d formed at the end of the output shaft 4, has the bearing 1
By abutting on the inner ring of No. 3, the bearing 13 is prevented from coming off from the output shaft 4. The other end surface of the retaining ring 52 is a tapered surface 52a such that the thickness of the retaining ring 52 decreases toward the inner side on the inner peripheral side, and the side surface of the circumferential groove 4d facing the tapered surface 52a of the retaining ring 52. Is a tapered surface 4d 'parallel to the tapered surface 52a, and both tapered surfaces 52a, 4d' are in contact with each other. As a result, since the pinion 7 and the rack 8 are helical, the axial force acting based on the road reaction force causes the axial force acting via the tapered surface 52a even if the output shaft 4 is displaced in the axial direction. As a result, the diameter of the retaining ring 52 elastically changes, and the retaining ring 52 can always be brought into contact with the inner ring of the bearing 13 and the tapered surface 4d 'of the circumferential groove 4d. As a result, play in the axial direction of the output shaft 4 with respect to the bearing 13 can be eliminated, and the retaining ring 52 can be easily fitted into the circumferential groove 4d. The outer diameter of the retaining ring 52 is slightly smaller than the inner diameter of the cap 51. As a result, the cap 51 can prevent the diameter of the retaining ring 52 from increasing due to an excessive axial force from coming off the circumferential groove 4d.

FIG. 5 shows a first modification of the present invention. The difference from the above-mentioned embodiment is that the first valve member 24 is forged by forming an open concave portion at one end in the axial direction on the inner circumference thereof, and one end side in the axial direction of the concave portion is closed by the output shaft 4, thereby performing left-right steering. The point is that the recesses R and L for use are formed. Other parts are the same as those in the above embodiment, and the same parts are indicated by the same reference numerals. According to this modification, the first
The molding process can be simplified as compared with the case where the recessed portions which are open on both ends in the axial direction are formed by forging on the inner circumference of the valve member 24.

6 and 7 show a second modification of the present invention.
The difference from the above embodiment is that one end of the torsion bar 3 is a cylindrical portion 3b, a sleeve 62 made of sintered metal or the like is fitted to the cylindrical portion 3b, and the sleeve 62 and the cylindrical portion 3b are pinned. 63 is inserted and its sleeve 6
2 is press-fitted into the output shaft 4 through the serrations 64, and a radial gap δb of the torsion bar 3 is formed between the sleeve 62 and the cylindrical portion 3b.
And a gap 63 in the radial direction of the pin 63 is formed between the pin 63 and the pin 63. Other parts are the same as those in the above embodiment, and the same parts are indicated by the same reference numerals. According to this modification, each of the gaps δb,
Due to δc, before connecting the torsion bar 3 and the input shaft 2, at both the connecting position of the one end of the torsion bar 3 and the output shaft 4 and the connecting position of the other end of the torsion bar 3 and the input shaft, The radial displacement of the axial center 3o of the torsion bar 3 is allowed. Further, since the torsion bar 3 is not directly connected to the output shaft 4 but is connected via the sleeve 62, it is not necessary to form a pin hole in the output shaft 4, and the pin hole is opened at the outer periphery of the output shaft 4. Therefore, there is no need to prevent interference between the opening of the pin hole and the bearing 12 that supports the output shaft 4 or the oil seal 47, and the layout of the components is not limited.

FIGS. 8 and 9 (1) and (2), and FIG. 10 (1), (2), (3) and FIG. 11 show a third modification of the present invention. The difference from the above embodiment is that (1) in FIG.
As shown in (2), one end 3c of the torsion bar 3
Has a portion protruding outward in the radial direction from the position of the outer circumference 4 at the other end, and thus has a cross-shaped cross section. FIG.
As shown in FIG. 3, a sleeve 72 made of sintered metal or the like is inserted into the one end portion 3 c, and the sleeve 72 is press-fitted into the output shaft 4. The press-fitting may be performed via serration. The inner peripheral hole of the sleeve 72 is (1) in FIG.
As shown in (2) and (3), one end side has a bottom view cross shape corresponding to the cross-sectional shape of the one end portion of the torsion bar 3,
The other end has a circular shape when viewed from the top, and the cross-shaped portion 72a when viewed from the bottom.
The boundary between the circular portion 72b and the circular portion 72b in a top view is a step 72c. By engaging one end 3c of the torsion bar 3 with the step 72c, the torsion bar 3 is prevented from slipping upward from the sleeve 72 in FIG.
As shown in FIG. 11, a radial gap δd of the torsion bar 3 is formed between the cross-shaped portion 72 a in bottom view of the inner circumferential hole of the sleeve 72 and the one end 3 c of the torsion bar 3. Other parts are the same as those in the above embodiment, and the same parts are indicated by the same reference numerals. According to this modification, due to the gap δd, the torsion bar 3 and the output shaft 4 are connected to each other at both the connecting position of the one end of the torsion bar 3 and the output shaft 4 and the connecting position of the other end of the torsion bar 3 and the input shaft. Before the connection with the input shaft 2, the radial displacement of the axial center of the torsion bar 3 is allowed. Further, since the torsion bar 3 is not directly connected to the output shaft 4 but is connected via the sleeve 72, it is not necessary to form a pin hole in the output shaft 4, and the pin hole is opened at the outer periphery of the output shaft 4. Therefore, there is no need to prevent interference between the opening of the pin hole and the bearing 12 that supports the output shaft 4 or the oil seal 47, and the layout of the components is not limited.

FIGS. 12A, 12B, 13A, 13B, 13C, and 14 show a fourth modification of the present invention. The difference from the third modified example is that, as shown in (1) and (2) of FIG. 12, first, one end portion 3d of the torsion bar 3 is stretched outward in the radial direction from the outer periphery 2 position of the other end portion. It has a projecting portion and a portion that is recessed inward in the radial direction from the position of the outer circumference 2, and has a semicircular shape in a side view. As shown in (1), (2), and (3) of FIG. 13, the inner peripheral hole of the sleeve 82 inserted into the one end portion 3d of the torsion bar 3 is:
One end side 82a has a shape into which the one end 3d and the other end side of the torsion bar 3 can be inserted, and the other end side 82b has a circular shape in a top view so that only the other end side of the torsion bar 3 can be inserted. The boundary between the one end side 82a and the other end side 82b is a step 82c. By engaging the one end 3d of the torsion bar 3 with the step 82c, the torsion bar 3 is prevented from coming off from the sleeve 82. As shown in FIG. 14, a radial gap δe of the torsion bar 3 is formed between one end side 82a of the inner peripheral hole of the sleeve 82 and one end 3d of the torsion bar 3. Others are the same as those in the third modified example, and the same portions are denoted by the same reference numerals.

The present invention is not limited to the above embodiments and modifications. For example, the number, arrangement, type, etc. of the recesses on the inner circumference of the first valve member are not limited to those in the above embodiment. Further, although the present invention is applied to the rack and pinion type hydraulic power steering device in the above embodiment, the present invention is not limited thereto.
For example, it can be applied to a ball screw type hydraulic power steering device.

[Brief description of drawings]

FIG. 1 is a sectional view of a hydraulic power steering device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a control valve of the hydraulic power steering system according to the embodiment of the present invention.

FIG. 3 is a sectional view of a main part of a hydraulic power steering device according to an embodiment of the present invention.

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

FIG. 5 is a sectional view of a hydraulic power steering device according to a first modified example of the present invention.

FIG. 6 is a sectional view of a hydraulic power steering device of a second modified example of the invention.

FIG. 7 is a partial cross-sectional view of a hydraulic power steering device according to a second modified example of the present invention.

FIG. 8 is a partial cross-sectional view of a hydraulic power steering device according to a third modified example of the present invention.

FIG. 9 is a side view of (1) and a bottom view of a torsion bar of a hydraulic power steering device of a third modified example of the invention.

FIG. 10 is a top view of a sleeve of a hydraulic power steering device according to a third modified example of the present invention, FIG.
(3) is a bottom view

FIG. 11 is a bottom view of a torsion bar and a sleeve of a hydraulic power steering device according to a third modified example of the present invention.

12A and 12B are a side view and a bottom view of a torsion bar of a hydraulic power steering device according to a fourth modification of the invention.

FIG. 13 is a top view, (2) is a side view of a sleeve of a hydraulic power steering device according to a fourth modification of the present invention;
(3) is a bottom view

FIG. 14 is a bottom view of a torsion bar and a sleeve of a hydraulic power steering device according to a fourth modified example of the present invention.

FIG. 15 is a sectional view of a conventional hydraulic power steering device.

[Explanation of symbols]

 2 Input shaft 4 Output shaft 18 Hydraulic cylinder 24 First valve member 25 Second valve member R Right steering recess L Left steering recess P Pressure oil supply recess T Pressure oil discharge recess

Claims (2)

[Claims] 1. An input shaft that is rotated by steering, an output shaft that is connected to the input shaft via a torsion bar, and a tubular first valve member that rotates together with the output shaft. A second valve member that rotates together, the second valve member being rotatably inserted into the first valve member, and extending axially along the inner circumference of the first valve member and the outer circumference of the second valve member. A plurality of recesses are formed at intervals in the circumferential direction, and the first valve member-side recess has an edge along the axial direction and a second recess.
Between the edge of the recess on the valve member side along the axial direction is a throttle whose opening changes due to relative rotation of both valve members, and the hydraulic pressure that acts on the steering assist force generating hydraulic actuator due to the change in the opening of the throttle. In a control valve for a hydraulic power steering device, the output shaft is press-fitted coaxially with the inner circumference of one end side of the first valve member in the axial direction, and the input shaft is coaxial with the inner circumference of the first valve member. A hydraulic power steering device, wherein the first valve member is rotatably supported by the first valve member, and one end side in the axial direction of the concave portion of the inner periphery of the first valve member is closed by an output shaft. 2. A torsion bar before connecting the torsion bar and the input shaft at at least one of a connecting position between the one end of the torsion bar and the output shaft and a connecting position between the other end of the torsion bar and the input shaft. The hydraulic power steering device according to claim 1, wherein one end of the torsion bar is connected to the output shaft so that radial displacement of the shaft center of the torsion bar is allowed.