JPH0229019Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to improvements in rotary control valves for power steering devices, and particularly to improvements in fixing the rotational direction of the valve body to the pinion shaft.

(Prior art) As a conventional power steering device, for example, Fig. 5~
A device as shown in FIG. 8 is known.

In FIG. 5, 1 is a gear housing;
The opening at one end of the gear housing 1 is closed by an adjusting bolt 2 via a nut 2A, and the opening at the other end is closed by a rear cover 3 via a seal 4. A pinion shaft 5 is rotatably supported within the gear housing 1 via bearings 6 and 7, and a pinion gear 5A is formed in the pinion shaft 5. This pinion gear 5
A rack 8 having a rack gear 8A meshing with gear A is supported by a rack guide 9 housed in an opening of the gear housing 1. In the opening of the gear housing 1, an adjusting screw 10 is attached to the nut 1.
1, and a spring 12 is compressed between the adjusting screw 10 and the rack guide 9. Therefore, by adjusting the screwing of the adjusting screw 10, a minute gap L is formed between the adjusting screw 10 and the rack guide 9. Reference numeral 13 denotes a stub shaft connected to a steering handle (not shown).
It is supported by the rear cover 3 via 5. A rotor 13A is integrally formed on the outer periphery of the stub shaft 13, and a torsion bar 13B is housed inside the stub shaft 13. Torsion bar 13
B has its leading end connected to the pinion shaft 5 via a pin 16, and its rear end connected to the stub shaft 13 via a pin 17. A shaft seal 18 provides a liquid-proof seal between the gear housing 1 and the pinion shaft 5. 19 is a valve body, and one end of this valve body 19 is formed with a long groove 19A in the axial direction. This long groove 1
A pin 20 is inserted into the valve body 9A, so that the valve body 19 and pinion shaft 5 can rotate together (FIGS. 6 and 7). Valve body 1
Three grooves 21, 22, and 23 are formed on the outer periphery of 9, one groove 22 is for the oil pump chamber, and the other two grooves 21, 23 are for the cylinder chambers A and B (not shown). are connected to each other. Also, the 8th
As shown in the figure, six land portions 19B and six grooves 19C are formed alternately in the circumferential direction on the inner periphery of the valve body 19.
9B and six grooves 13C formed on the rotor 13A.
and constitute the variable orifice 24, respectively. The valve body 19 also has three communication holes 25 that communicate with the grooves 13C of the rotor 13A.
are formed in each rotor 13A, and three through holes 27 are formed in the rotor 13A to communicate these grooves 13C with an annular groove 26 formed between the torsion bar 13B.

Therefore, when the stub shaft 13 is rotated clockwise or counterclockwise by rotating the steering handle (not shown), the torsion bar 13
The pinion shaft 5 also attempts to rotate via B, but in the initial rotation state of the stub shaft 13, it is receiving ground resistance from the axle via the steering link to which the rack 8 is connected, so the pinion shaft 5 remains motionless, but the torsion bar 13B is twisted, and the valve body 19, which is connected to the pinion shaft 5 by a pin 20, and the stub shaft 13.
A relative rotation occurs between the rotor 13A and the rotor 13A. Therefore, the variable orifice 24 formed between the land portion 19B of the valve body 19 and the groove 13C of the rotor 13A is opened or narrowed. for example,
When the steering handle is rotated clockwise, the rotor 13A rotates to the right with respect to the valve body 19. That is, a predetermined variable orifice 24 is throttled, and hydraulic oil is supplied to the cylinder chamber A, but not to the cylinder chamber B. For this reason,
A power piston (not shown) moves due to the oil pressure difference, and an assisting force is applied to clockwise steering of the steering wheel. Further, when the steering handle is rotated counterclockwise, hydraulic oil is not supplied to the cylinder chamber A but is supplied to the cylinder chamber B, contrary to the case described above. Therefore, the piston moves in the opposite direction due to the oil pressure difference, and an assisting force is applied to counterclockwise steering of the steering handle. In this way, steering assistance is performed in response to the rotational operation of the steering handle. Note that when the steering handle is in the neutral position, that is, when the vehicle is traveling straight, there is no twisting of the torsion bar 13B and no relative rotation between the valve body 19 and rotor 13A, so no oil pressure difference occurs. The piston is therefore stationary in its neutral position.

(Problem to be solved by this invention) However, in such conventional power steering devices, a long groove is formed in the valve body, and a pin is inserted into the long groove to rotate the valve body and pinion shaft. Since the pin was fixed in the direction, there was a limit to the machining accuracy of the groove, and play occurred between the pin and the long groove. As a result, the hydraulic non-buffer zone increases by the amount of this backlash, and this backlash causes vibration in the valve body, resulting in an increase in noise.

(Means for solving the problem) This invention was made to solve the above problem, and has a valve body rotatably and slidably supported on a stub shaft,
An engagement pin protruding from the output shaft member is inserted into an engagement groove extending in the axial direction of the valve body, so that the output shaft member and the valve body can rotate together, and the output shaft member and stub Torsional deformation of the torsion bar that connects the shaft causes a relative rotational displacement between the valve body and the stub shaft, and this relative rotational displacement controls the pressure fluid generated by the fluid pump to supply and discharge it to and from the power cylinder, thereby controlling the steering. In a control valve of a power steering device that assists steering of a steering wheel,
The engaging groove is formed so that its width changes continuously along its axial direction, and the engaging pin is urged to urge the valve body so that it is always in contact with the inner wall surface of the engaging groove. This means that a means has been established.

(Function) In this device having such a configuration,
A tapered groove is formed in the axial direction on one end of the valve body, and a pin is inserted into this tapered groove to connect the valve body and pinion shaft, while also biasing the other end of the valve body in one direction. There is no play between the pin and the pin. Therefore, the valve body and pinion shaft are tightly connected with no gaps in the rotational direction, so that the non-buffer zone of the hydraulic pressure does not increase, and the vibration of the valve body does not increase.

(Example) Hereinafter, an example of this invention will be described based on the drawings.

1 to 4 are diagrams showing an embodiment of this invention. Note that the same components as in the conventional example are given the same reference numerals, and the explanation thereof will be omitted.

First, to explain the configuration, in Figure 1, 1
9 indicates a valve body, and this valve body 19
An engagement groove (tapered groove) 30 is formed in the axial direction on one end side. As shown in FIGS. 2 and 3, this tapered groove 30 is formed so that its width becomes smaller as it goes from one end side to the other end side of the valve body 19, and a pinion is provided in this tapered groove 30. A pin 20 is press-fitted into the large diameter portion of the shaft 5 (output shaft member). Therefore, the pinion shaft 5 and the valve body 19 are connected via the pin 20, and the pinion shaft 5 and the valve body 19 can rotate together within the gear housing 1. on the other hand,
A spring 32 (biasing means) is compressed between the other end of the valve body 19 and the rear cover 3 via a bearing 31. Therefore, the valve body 19 is urged in the axial direction by the spring 32, and the pin 20 is tightly fitted into the tapered groove 30 without any gap. Further, when the valve body 19 rotates, it is urged by the spring 32 and rotates together with the spring 32 and the bearing 31. In addition, 33 is valve body 1
This is a snap spring that restricts the axial displacement of 9.

Next, the action will be explained.

When the stub shaft 13 is rotated clockwise or counterclockwise by rotating a steering handle (not shown), the pinion shaft 5 also tries to rotate via the torsion bar 13B, but the stub shaft 13 Easy 8 in the initial state of rotation.
The pinion shaft 5 remains stationary, and the torsion bar 13, which has flexibility, receives ground resistance from the wheels via the steering link to which it is connected.
A twist angle occurs at B. For this reason, valve body 1
9 and the rotor 13A, the variable orifice 24 is opened or constricted, and hydraulic oil is supplied to either the cylinder chambers A or B. .
This hydraulic oil pressure difference causes the piston to move in one direction, and the steering handle is given an assisting force for clockwise or counterclockwise steering. . and,
As the piston moves, the twisted torsion bar 13B returns to its neutral state, and the displacement between the valve body 19 and the rotor 13A also returns to its neutral state.

Here, in this embodiment, a tapered groove 30 is formed in the valve body 19, and the tapered groove 30 is formed in the valve body 19.
Since the pin 20 is inserted into the pinion shaft 5 to connect the valve body 19 and the pinion shaft 5, and the valve body 19 is urged in the axial direction by the spring 32, play occurs between the pin 20 and the tapered groove 30. Therefore, the pinion shaft 5 and the valve body 19 smoothly rotate together without play. As a result, the oil pressure non-buffer zone does not increase, and the valve body 19
vibration and noise will not increase. Furthermore, in this case, there is no need to improve the machining accuracy of the pin 20 and the groove 30, so costs can be reduced.

(Effects) As explained above, according to this invention,
Since the play that occurs between the taper groove formed in the valve body and the pin can be reduced to zero, it is possible to prevent an increase in the non-buffer zone of hydraulic pressure, and it is also possible to prevent an increase in noise due to vibration of the valve body. .

[Brief explanation of the drawing]

1 to 4 are views showing one embodiment of the control valve of the power steering device according to this invention, FIG. 1 is a longitudinal sectional view thereof, and FIG. View, Figure 3 is a view from arrow B in Figure 2,
FIG. 4 is a view taken along the line C-C in FIG. 1, FIGS. 5 to 8 are views showing a control valve of a conventional power steering device, FIG. 5 is a longitudinal sectional view thereof, and FIG. 7 is a view taken along arrow B in FIG. 6, and FIG. 8 is a view taken along arrow C-C in FIG. 5. 5...Pinion shaft (output shaft member), 13
...Stubshaft, 13A ...Rotor, 13B
... Torsion bar, 19 ... Valve body, 2
0...Pin, 30...Groove, 32...Spring (biasing means).

Claims (1)

[Scope of utility model registration request] A valve body is rotatably and slidably supported by a stub shaft, and an engagement pin protruding from the output shaft member is inserted into an engagement groove extending in the axial direction of the valve body. The output shaft member and the valve body are made integrally rotatable, and a relative rotational displacement is generated between the valve body and the stub shaft by torsion deformation of the torsion bar that connects the output shaft member and the stub shaft, and this relative rotational displacement causes the fluid pump to rotate. In a control valve of a power steering device that controls generated pressure fluid to supply and discharge it to a power cylinder to assist in steering a steering wheel, the engagement groove is continuously inserted in the axial direction of the control valve. A control for a power steering device, characterized in that the valve body is formed to have a variable width and is provided with a biasing means for biasing the valve body so that the engagement pin is always in contact with an inner wall surface of the engagement groove. valve.