JPH0216938Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a rotation control valve device for hydraulic reaction power steering.

(Prior Art) FIG. 1 shows a conventional rotation control valve device for hydraulic reaction force type power steering. Reference numeral 1 denotes an input shaft connected to the handle, which is inserted into the center of the housing 2 from above. 3 has an upper part fixed to the upper part of the input shaft 1 by a torsion bar, and a lower part fixed to an output shaft 7 integral with a pinion 6 rotatably supported by bearings 4 and 5 in the housing 2. A valve body 8 is fitted between the input shaft 1 and the housing 2 and rotates together with the output shaft 7. Reference numeral 9 denotes a reaction force portion formed on the upper part of the output shaft 7, which forms a plurality of cylinder chambers 10 in the radial direction, into which a reaction force piston 11 is inserted.
Reaction pressure sent from a pressure control device (not shown) is guided to the reaction piston 11, and the hollow portion 11a at the tip of the reaction piston 11 is pressed against the vertical groove 1a formed on the outer periphery of the lower part of the input shaft 1, thereby controlling the torsion bar 3. It is designed to control twisting. A predetermined gap l is provided between the outer surface of the reaction force part 9 and the inner surface of the housing 2, as shown in FIG. When installed, it provides a tight seal and absorbs the lateral wobbling of the pinion 6.

When the vehicle is stopped, no pressure is applied to the reaction force section 9 and the seal member 12 is not in contact with the annular groove 9a of the reaction force section 9 as shown in FIG. However, at high speeds, the pressure in the reaction force chamber increases and is guided to the reaction force part 9, so that the sealing member 12 is pressed against the side surface of the annular groove 9a of the reaction force part 9 and the inner surface of the housing 2, as shown in FIG. When the steering wheel is steered in this state, the output shaft 7 rotates and sliding resistance is generated between the output shaft 7 and the seal member 12, and as the reaction force in the reaction force chamber increases, the sliding resistance also increases, resulting in an uncomfortable feeling when steering. This leads to a decrease in the steering feeling, and also has the disadvantage that when the steering wheel returns, it returns poorly.

(Purpose) This invention increases the pressure in the reaction force chamber sufficiently in the neutral position at high speeds, increases the steering force of the steering wheel, eliminates swaying, increases driving stability, and resists rotational sliding of the output shaft when steering the steering wheel. The aim is to improve the steering feel by minimizing the discomfort caused by the steering sensation.

(Embodiment) FIGS. 5 and 6 show a first embodiment of the present invention.
1 is an input shaft connected to the handle, and housing 2
It is inserted into the center from above. 3 has an upper part fixed to the upper part of the input shaft 1 by a torsion bar, and a lower part fixed to an output shaft 7 integral with a pinion 6 rotatably supported by bearings 4 and 5 in the housing 2. A valve body 8 is fitted between the input shaft 1 and the housing 2 and rotates together with the output shaft 7. Reference numeral 20 denotes a seal tube that is floatingly supported on the inner surface of the housing 2 via a sealing material 21, and the outer surface of a reaction portion 22 formed on the output shaft 7 is loosely fitted into the inner surface of the seal tube 21 with extremely low rotational and sliding resistance. Four cylinder chambers 22a are formed in the radial direction of the reaction force section 22, into which the reaction piston 23 is fitted, and the tip protrusion 23a of the reaction piston 23 is inserted into the vertical groove 1a formed on the lower outer periphery of the input shaft 1. It is designed so that it can be inserted.

Next, the effect will be explained. When the input shaft 1 is rotated by steering the steering wheel, the pinion 6 is rotated via the torsion bar 3, and the output shaft 7 is also rotated together. At this time, the horizontal vibration of the pinion 6 is caused by the seal member 21.
The seal cylinder 20, which is floatingly supported, absorbs it.

When the vehicle is stopped, the pressure in the reaction force chamber is not acting on the reaction force part 22, but as the vehicle speed gradually increases and becomes high speed, the pressure in the reaction force chamber increases and is guided to the reaction force part 22, so that the reaction force piston 23 is pressed toward the vertical groove 1a on the outer surface of the lower part of the input shaft 1, and the torsion bar 3 is restricted from twisting by the pressing force.

FIG. 7 shows a second embodiment of the present invention. Input shaft 3
A protrusion 31a is provided at the bottom of 1, and the protrusion 31a
The torsion of the torsion bar 3 is regulated by applying the pressing force of the reaction piston 33 fitted into the cylinder chamber 32a of the reaction force section 32.

(Effect) According to the present invention, the rotation of the handle input shaft is transmitted to the oil passage switching valve integrated with the output shaft via the torsion bar, and the pressure oil from the oil pump is applied in the steering direction, and the pressure in the reaction force chamber is transmitted to the torsion bar. In a hydraulic reaction force type power steering rotation control valve device which is configured to act on the cylinder and restrict its twisting, the outer surface of the seal cylinder is floatingly supported on the inner surface of the housing via a sealing material, and the reaction force of the output shaft is supported on the inner surface of the seal cylinder. The outer surface of the force part is loosely fitted in a state where the rotational sliding resistance is extremely small, and the reaction piston is fitted into the cylinder formed in the radial direction of the reaction force part, so that the tip of the reaction piston can press the outer periphery of the input shaft. Therefore, the steering wheel steering torque can be determined by the torsion of the torsion bar itself and the reaction pressure sent from the reaction force chamber. For example, by controlling the pressure of the reaction force chamber depending on the vehicle speed, the steering wheel steering torque can be determined by the As shown in the figure, it is possible to eliminate wobbling by making the vehicle lighter when stopped and heavier when driving at high speed, increasing the sense of running stability, eliminating discomfort in the steering sensation, and improving the steering feeling.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway front view of the conventional device, Fig. 2 is an enlarged front sectional view of the main part of Fig. 1, Fig. 3 is a front sectional view of Fig. 2 when no pressure is applied to the sealing part, Figure 4 is a front sectional view when the same pressure is applied, Figure 5 is a partially cutaway front view of the first embodiment of the present invention, and Figure 6 is a front view of the fifth embodiment.
7 is a diagram corresponding to FIG. 6 of the second embodiment of the present invention, and FIG. 8 is a graph of the hydraulic pressure of the steering force. 1...Input shaft, 2...Housing, 3...Torsion bar, 6...Pinion, 7...Output shaft, 8
...Valve body, 20...Seal tube, 21...
... Seal member, 22, 32 ... Reaction force part, 22a,
32a... Cylinder chamber, 23, 33... Reaction piston.

Claims (1)

[Scope of utility model registration request] The rotation of the steering wheel input shaft is transmitted to the oil passage switching valve integrated with the output shaft via the torsion bar, and the pressure oil from the oil pump is applied in the steering direction, and the pressure in the reaction force chamber is applied to the torsion bar to regulate its twisting. In such a hydraulic reaction force type power steering rotation control valve device, the outer surface of the seal cylinder is floatingly supported on the inner surface of the housing via a sealing material, and the outer surface of the reaction force portion of the output shaft is attached to the inner surface of the seal cylinder to provide rotational sliding resistance. Rotation of a hydraulic reaction type power steering system in which a reaction piston is fitted loosely into a cylinder formed in the radial direction of the reaction part, with a very small amount of force, and the tip of the reaction piston is able to press the outer periphery of the input shaft. Control valve device.