JPH03193556A - Rack-and-pinion power steering gear - Google Patents

Abstract

PURPOSE:To simplify the whole structure and reduce the cost of production as well as to dispense with the assembling and adjusting operations of a supporting means by making a bush, supporting a rack bar on a casing, so as to have an elastic part which presses the rack bar toward a pinion. CONSTITUTION:A bush 10 supports a surface at the opposite side to a pinion 2 of a rack bar 4, and it has an elastic part 11 pressing this rack bar 4 toward the pinion 2. This bush 10 is made of an elastic body consisting of urethane or rubber or the like as a whole, while the elastic part 11 is solidly formed after enlarging the extent of wall thickness in the bush 10. When the bush 10 is made of metal and plastics, the elastic part 11 is formed by means of attaching an elastic body to an inner surface of a metal or plastic ring. Plural numbers of projections 12 are installed on an outer circumference of this bush 10, and each of these projections 12 is engaged with a recess or step part 1a formed on the inner surface of a casing, through which the bush 10 will not move in the axial direction of the rack bar 4.

Description

[Detailed Description of the Invention] The present invention relates to an improvement in a rack and pinion power steering gear, and more specifically, a rack and pinion power steering gear in which a rack bar is effectively supported by a casing with a simple structure. This relates to steering gear.

Conventionally, this type of hook-and-pinion power steering gear has a pinion 2 connected to a steering wheel (not shown) and rotatably supported within a casing 1, and this pinion as shown in FIG. It consists of a rack bar 4 having rack teeth 3 that mesh with the pinion, and support means 5 for supporting the part of the rack bar on the side opposite to the pinion. This support means includes a support yoke 6 that contacts the rack bar, a spring 7 that presses this support yoke against the rack bar, a yoke plug 8 that supports the support yoke and the first spring, and a lock nut that fixes this yoke plug to the casing 1. It is equipped with

However, the prior art as described above has the disadvantage that the supporting means for supporting the rack bar requires a large number of parts and is therefore expensive. Another disadvantage is that the assembly and adjustment of this support means is difficult.

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

In order to achieve the above-mentioned object, the present invention eliminates the supporting means in the prior art described above, and supports the rack bar on the casing only by bushings having a simple structure.

1-Dish This bush supports the portion of the rack bar opposite to the pinion, and always urges the rack bar toward the pinion.

(9) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Referring to FIGS. 1 and 2, there is shown a rack and pinion power steering gear of the present invention.
In the figures and FIG. 2, the same parts as in FIG. 3 are designated by the same reference numerals.

In the present invention, the rack bar 4 has at least one bushing 10.
Note that it is supported on the casing 1 by a chisel. A plurality of such bushings may be provided, and it is preferable that the bushings be arranged close to the pinion 2. As shown in FIG. 2, this bush supports the surface of the rack bar 4 on the side opposite to the N side of the pinion 2. This bushing has an elastic portion 11 that presses the rack bar toward the pinion. It is preferable that the bushing is made entirely of an elastic material such as urethane or rubber, and in such a case, the elastic portion 11 is formed integrally by increasing the wall thickness of the bushing.

This elastic portion may be formed separately from the bushing.

If the bushing is made of metal or plastic, for example, the elastic part 11 is formed by attaching an elastic body to the inner surface of a ring made of metal or plastic.

The outer periphery of this bushing is provided with a plurality of projections 12 which can engage in recesses or steps 1a (see FIG. 1) formed in the inner surface of the casing.

This prevents the bush from moving in the ring direction of the rack bar.

Next week! (According to the present invention, as described above, the rack cover is supported by the casing only by the bushings of a simple structure, so there is no need for the supporting means of the prior art, and therefore the entire rack and pinion power steering gear is The structure of the present invention is extremely simple and the cost is reduced.Furthermore, there is a practical advantage that there is no need for assembling and adjusting the support means as in the prior art.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a rack and pinion power steering gear according to the present invention, FIG. 2 is a sectional view of a bushing, and FIG. 3 is a sectional view of a conventional rack and pinion power steering gear. 1. Casing, 2. Pinion, 4. Rack bar 10. Bush, 11. Elastic part, 12.
·protrusion.

Claims (1)

[Claims] A rack and pinion power steering gear comprising a casing, a rack bar slidably disposed within the casing, and a pinion that meshes with hook teeth provided on the rack bar, the rack bar having at least supported on the casing by only one bushing;
A rack and pinion power steering gear, wherein the bush has an elastic portion that presses the rack bar toward the pinion.