JPS6362956A - Rack gear supporting device - Google Patents

Abstract

PURPOSE:To improve the steering efficiency, and prevent the generation of noise during operation, by integrally connecting a yoke having a rack gear receiving surface with a roller adapted to contact a rack gear through an elastic member. CONSTITUTION:A yoke 11 is biased by a spring 17 to bring a receiving surface 13 into contact with a rack gear 12. A roller 20 is rotatably supported to a shaft 21. The shaft 21 is supported at its both ends through elastic members 22 to the yoke 11. Let a quantity of change in distance (a) from a center of the rack gear 12 to a back surface thereof denote DELTAa, a pressure of the spring 17 denote P1, and a pressure of the elastic members 22 corresponding to the quantity of change DELTAa denote P2, the elastic characteristic of the elastic members 22 is so set as to satisfy P2>P1. Accordingly, a sliding contact between the receiving surface 13 and the rack gear 12 and a rolling contact between the roller 20 and the rack gear 12 are continuously changed. Thus, it is possible to improve a steering efficiency, reduce a manufacturing cost, and prevent the generation of noise during operation.

Description

[Detailed description of the invention] The present invention relates to a rack gear support device, and more particularly to a rack gear support device.

This invention relates to an improvement of a rack gear support device in a rack and pinion steering mechanism.

PRIOR ART In general, in a rack-binion steering mechanism consisting of a pinion connected to a steering wheel and a rack gear having rack teeth that mesh with the pinion and wheels connected to both ends, the surface of the rack gear on the opposite side from the pinion is used. A support device is provided for supporting the.

This type of support device applies a moderate amount of frictional force to the rack gear when the vehicle is traveling straight, making the steering wheel moderately heavy, and as the vehicle is steered, that frictional force is reduced to gradually make the steering wheel lighter. Designed.

A conventional support device of this type is shown in FIG. This support device has a housing 1, a yoke 2 disposed within the housing, and a roller 6 disposed on the yoke. The yoke 2 has a receiving surface 5 for receiving the rack gear 4 at one end, and the yoke is biased by a spring disposed between the yoke and the housing so that the receiving surface 5 presses against the rack gear. The rack gear 4 has rack teeth 4aY, and a pinion 7 meshes with the rack teeth. A shaft 7a of this pinion 7 is connected to a steering wheel (not shown) of an automobile. Note that the distance a between the surface 7) with which the rollers of the rack gear come into contact and the center line 4C of the rack gear is set to be larger at both ends of the rack gear than at the center of the rack gear.

The roller 6 is rotatably supported by a shaft 8, and this shaft is fixed to a bearing body 9. This bearing body is slidably housed in a recessed hole 10 provided in the yoke, and is biased toward the rack gear by a spring 11 provided between the bearing body and the housing. Incidentally, reference numeral 2a indicates a closure plate fixed to the yoke so as to partially close the opening of the recessed hole 10.

In this support device, when the automobile is traveling straight (at the center position of the rack gear), the receiving surface 5 of the yoke 2 and the roller 5 contact the rack gear with an appropriate pressure, and apply an appropriate frictional force to the steering wheel. When the steering wheel is rotated in one direction from this state, the rack gear 4 is gradually moved in the axial direction from its center position by a certain degree via the pinion 7.

The roller 6 is pushed to the right as seen in FIG. ``ru'' by moving a certain distance to the right with .

Problems to be Solved by the Invention However, such prior art has a large number of parts because it consists of a yoke, a bearing body attached to the yoke, a roller attached to the bearing body, a closure plate, and two springs. There are a lot of them, and this has the disadvantage of high manufacturing costs. Furthermore, since there are a large number of parts, there is a large variation in the setting of the six dimensions between the bearing body and the closure plate due to a change in one dimension, as shown in FIG. 5, resulting in poor efficiency in the above-mentioned operation. Another drawback is that noise is generated during operation due to the gaps that exist between the receiving surface of the yoke and the rack gear, and between the yoke and the bearing body.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rack gear support device that overcomes the drawbacks of the prior art as described above.

Means for Solving the Problems In order to achieve the above object, in the present invention, a yoke and a roller are integrally connected via an elastic body.

Examples Examples of the present invention will be described below with reference to FIGS. 1 and 2.
Explain in detail.

In FIG. 1, reference numeral 10 indicates a housing.

A yoke 11 is provided within this housing. A receiving surface 15 for receiving the rack gear 12 is provided at one end of the yoke.

The rack gear 12 has rack teeth 14, with which a pinion 15 meshes. pinion is 7yaft 1
6 to a steering wheel (not shown). Wheels to be steered are connected to both ends of the rack gear via appropriate link devices (not shown), as in the prior art described above.

The yoke 11 is biased by a spring 17 disposed between the end surface opposite to the receiving surface 15 and the housing 10 so that the first receiving surface 13 is always in contact with the rack gear with an appropriate pressure.

A roller 2D is rotatably supported on the yoke 11. This roller is rotatably supported by a shaft 21, and both ends of this shaft are supported by the yoke 11 via elastic bodies 22. This elastic body is made of a tubular body made of rubber, for example, and the shaft 21
are press-fitted into both ends of the yoke 11, respectively, and into a recessed hole provided in the yoke 11. The spring characteristics of this elastic body are the first
As shown in the figure, the amount of change in the distance a from the center of the rack gear to the rear surface of the rack gear (this distance is set in the same way as in the case of the prior art shown in FIG. 6) is defined as Δa, and the spring 17
As shown in Figure 2, if the pressure of the elastic body is P2 corresponding to the amount of change △a, then P2)P+
It is set so that

By setting the pressure between the elastic body 22 and the spring 17 as described above, sliding contact between the receiving surface of the yoke and the rack gear and rolling contact between the roller and the rack gear can be prevented while the rack gear is moving in its axial direction. Can change continuously.

Effects of the Invention According to the present invention, since the sliding contact and the rolling contact for supporting the rack gear change continuously, it is possible to improve steering efficiency such as good steering performance, and to improve the steering system. There is a practical benefit in that you can get one benefit from it. Furthermore, since the number of parts can be reduced, manufacturing costs are low. Furthermore, there is an advantage in that there are fewer gaps between the parts, and therefore the generation of noise during operation can be prevented.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a rack gear support device according to the present invention, FIG. 2 is a graph showing the spring characteristics of an elastic body, and FIG. 6 is a sectional view of a conventional rack gear support device. 11...Housing, 12...Rack gear, 15
...Receiving surface, 17...Spring, 20...Roller. (5 other people) 16 Figure 1

Claims (1)

[Claims] A housing, and a support means movably provided within the housing so as to approach or move away from the rack gear to be supported, the support means having a yoke having a receiving surface for receiving the rack gear, and a support means provided on the yoke. A rack gear support device comprising: a roller rotatably provided via an elastic body and capable of contacting a rack gear; and a spring pressing the yoke so that its receiving surface comes into contact with the rack gear.