JPH0742914Y2 - Rack and pinion steering device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a rack and pinion type steering device.

[Conventional technology]

Generally, a rack and pinion type steering device connects tie rods for transmitting reciprocating motion of a rack shaft to turn traveling wheels through ball joints screwed to both ends of the rack shaft. The inner end surface of the ball joint is set to a range until it interferes with the contact portion of the rack housing.

In such a case, both the rack housing and the ball joint are made of metal, and at the time of the above-mentioned interference, the impact force applied to the meshing teeth of the rack and the pinion is large, and a large collision sound between the metals is generated. In the past, this was absorbed by a cushioning member provided between the ball joint and the abutting portion of the rack housing (Japanese Utility Model Publication No. 62-165174).

[Problems to be solved by the device]

However, in the conventional apparatus in which the cushioning member is simply installed between the ball joint and the abutting portion of the rack housing, when the steering is moved to the stroke end during the normal steering, the cushioning member is changed from the unloaded state to the compressed load. However, there is a problem in that the feeling of the stopper is weakened.

In view of the above points, the present invention has an object to obtain a rack and pinion type steering device capable of reducing the impact force when the ball joint and the rack housing interfere with each other without impairing the stopper feeling during normal steering. To do.

[Means for Solving the Problems]

The rack and pinion steering apparatus according to the present invention is such that the rack shaft is formed with a stepped end face facing the ball joint end face, and a cushioning member is pressure-bonded and fixed between these end faces.

[Action]

In the present invention, since it is possible to apply a compressive force to the cushioning member in advance, a reaction force from the cushioning member side, that is, a stopper feeling can be given to the driver from the initial stage of the interference between the ball joint and the rack housing. In addition to the above, the impact force applied to the meshing teeth of the rack and the pinion can be reduced as in the conventional case.

〔Example〕

Hereinafter, the present invention will be described based on illustrated embodiments. FIG. 1 is an overall configuration diagram of a rack and pinion type steering device, and FIG. 2 is an enlarged cross-sectional view of a main portion thereof, showing a rack shaft (2) slidably supported in a rack housing (1). ), The ball joints (4) provided at the ends of the tie rods (3) are screwed and fixed respectively. Further, the rack shaft (2) has small diameter portions (2a) formed at both ends thereof, and the rack housing (1) is formed in these small diameter portions (2a).
An annular cushioning member (5) having a diameter substantially equal to the outer diameter of the end face (1a) is fitted. The cushioning member (5) includes an elastic body (5a) such as rubber and a pair of reinforcing plates (5a).
It consists of a triple structure sandwiched between b) and (5c), and is sandwiched between the step end face (2b) of the rack shaft (2) and the inner end face (4a) of the ball joint (4) facing it. When the ball joint (4) is screwed onto the rack shaft (2), the ball joint (4) is pressed and fixed in the axial direction. That is,
When the ball joint (4) is screwed onto the rack shaft (2), a pair of reinforcing plates () are formed by the inner end surface (4a) of the ball joint (4) and the step end surface (2b) of the rack shaft (2). The elastic body (5a) sandwiched between 5b) and (5c) is fixed while being axially compressed.

Therefore, in the device of this embodiment, when the steering angle is large, the rack shaft (2) is moved in the axial direction via the pinion, and the buffer member (5) interferes with the end surface (1a) of the rack housing (1). When the stroke is limited, if the load is low, the driver directly receives the reaction force from the cushioning member (5) side and the load is larger than the stored force of the cushioning member (5). In some cases, this is absorbed by the elastic force of the cushioning member (5), and the impact force applied to the meshing teeth of the rack and pinion is mitigated as in the conventional case.

In the above embodiment, the cushioning member (5) is composed of a triple structure in which an elastic body (5a) such as rubber is sandwiched by a pair of reinforcing plates (5b) and (5c), but the present invention is not limited to this. However, for example, the reinforcing plate (5c) located on the step end face (2b) side of the rack shaft (2) is configured as one spring seat, and the inner end face (4b) of the ball joint (4) is configured as the other spring seat. Then
A coil spring may be mounted between them,
Even in such a case, it is possible to obtain the same effects as those of the above embodiment.

[Effect of device]

As described above, according to the present invention, since it is possible to apply a compressive force to the cushioning member in advance, it is possible to give a feeling of stopper to the driver from the initial stage of cushioning the ball joint and the rack housing. As well as
There is an effect that the impact force applied to the meshing teeth of the rack and pinion can be reduced as in the conventional case.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a rack and pinion type steering device according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of a main part thereof. (1) …… Rack housing, (1a) …… Rack housing end face (contact part), (2) …… Rack shaft, (2b)…
… Step end of rack shaft, (3) …… Tie rod, (4)
…… Ball joint, (4a) …… Inner end surface of the ball joint, (5) …… Cushioning member.

Claims (1)

[Scope of utility model registration request] 1. A stroke end of a rack shaft is regulated by interfering an inner end surface of a ball joint for connecting a tie rod screwed to an end portion of the rack shaft with an abutting portion of a rack housing via a buffer member. In the rack and pinion steering device, a rack pinion steering device is characterized in that a step end surface facing the ball joint end surface is formed on a rack shaft, and the cushioning member is pressure-bonded and fixed between the end surfaces. .