JPS6116216Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an elastic device for elastically engaging a rack with a pinion in a rack-and-pinion type steering device for a vehicle such as an automobile.

FIG. 1 shows an example of a conventional device. In the drawing, a pinion 2 is rotatably supported within a gearbox 1, connected to a handle shaft (not shown), and rotated by rotation of the handle. A rack 3 forming part of the steering link is axially movably supported in the gearbox 1 and meshes with the pinion 2. The rack guide 4 is slidably inserted into an inner hole 5 provided in the gearbox 1 and comes into sliding contact with the back surface of the rack 3. is elastically engaged with the pinion 2, thereby eliminating backlash at the engagement portion between the rack 3 and the pinion 2.

In this type of device, it is desirable that the spring load that presses the rack 3 is small in terms of the feeling of steering wheel operation, but on the other hand, when the load is high or when an impact force from the road surface is applied, the rack guide 4 is For return, rack 3 and pinion 2
In addition, the rack guide 4 collides with the lid 6 and generates a knocking sound, so a large load is required to resist the return of the rack guide 4.

Conventionally, as shown in FIG. 1, a compression coil spring 7 is provided between the rack guide 4 and the lid 6, and a disc spring 8 is provided on the collision surface of the rack guide 4 and the lid 6. There are known devices that attempt to buffer collisions with other objects and reduce the sound of hitting. However, in order to obtain a sufficient effect, the spring load of the disc spring 8 must be made considerably large, and as a result, the total spring load that presses the rack guide 4 becomes large, and in practical use, the feeling of light steering wheel operation is reduced. The problem was that it damaged the

In addition, in Utility Model Publication No. 56-30536, a coil spring with a special shape and non-linear characteristics is used in place of the above-mentioned disc spring, and while the load at the time of setting is kept small, the spring suddenly springs up in response to a sudden return of the rack guide. Rack 3 and pinion 2 by increasing the load
A device has been proposed that eliminates the inconvenience of the meshing part and prevents the hammering sound. This invention has the advantage of simultaneously obtaining a small spring load during normal operation and a large spring load that resists the return of the rack guide 4, but it requires a specially shaped coil spring, so the manufacturing cost is high. Another problem was that the nonlinear spring characteristics varied greatly during manufacturing, resulting in a lack of reliability.

The present invention was developed in consideration of these points, and without using a specially shaped spring, the spring load can be set to a small value during normal operation, but the spring load can be suddenly adjusted to prevent the rack guide from returning under high load. It is an object of the present invention to provide a springing device for a rack and pinion type steering device which can resist the return of a rack guide by increasing the load.

The present invention will be described in detail below with reference to the embodiment shown in the drawings. Fig. 2 is an enlarged view of the main part of one embodiment of the present invention. In the drawing, an annular step 4a is formed on the disc spring bearing surface of the rack guide 4 that presses the rack 3. This step 4a is normally supported by the disc spring 8.
3, the disc spring 8 is set to come into contact with the disc spring 8 in the middle of the deformation process of the disc spring 8 as the rack guide 4 moves backward. When the device is assembled and set, that is, in the normal use state, as shown in Fig. 2, the disc spring 8 applies its own spring load to the rack guide 4 regardless of the presence of the step 4a, but when the rack guide 4 moves backward due to a high load or impact force from the road surface, the disc spring 8 in the middle of the deformation process comes into contact with the step 4a as shown in Fig. 3, and its inner diameter support position changes from _r1 to _r1 ', and the spring constant increases suddenly. Therefore, while the total spring load with the compression coil spring 7 in the normal use state is set to be small, a large spring load can be used to resist the return of the rack guide 4 when a high load or impact force from the road surface is transmitted.

FIG. 4 shows another embodiment of the present invention. In this embodiment, the annular stepped portion 6a that the disc spring 8 abuts during the deformation process of the disc spring 8 as the rack guide 4 returns. It is formed on the disc spring receiving surface of the lid body 6. During the retraction process of the rack guide 4, the disc spring 8 comes into contact with the stepped portion 6a, and its outer diameter support position changes from _r2 to _r2 ', making it possible to rapidly obtain a large spring constant.

Since the present invention is as described above, without using a specially shaped spring, the spring load during normal operation is set small, and the spring load is suddenly increased in response to the return of the rack guide. It is possible to obtain an elastic device capable of resisting the spring force, and furthermore, by changing the position of the stepped portion that abuts the disc spring, it is possible to easily change the change characteristics of the spring load.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view showing a conventional example, Figs. 2 and 3 are enlarged views of essential parts showing an embodiment of the present invention, and Fig. 4 is a longitudinal sectional view showing a conventional example.
The figure is an enlarged view of main parts showing another embodiment of the present invention. Explanation of symbols: 1...Gearbox, 2...Pinion, 3...Rack, 4...Rack guide, 5...
...Inner hole, 6...Lid, 7...Compression coil spring, 8
...Disc spring, 4a, 6a...stepped portion.

Claims (1)

[Scope of utility model registration request] A pinion 2 is rotatably supported in a gearbox 1, a rack 3 is meshed with the pinion 2 and movable in the axial direction, and a compression coil spring 7 and a disc are provided between the rack guide 4 and the lid 6. Rack 3 is connected to pinion 2 by spring 8.
In a rack-and-pinion type steering device in which the rack-and-pinion type steering device is resiliently engaged with the rack guide 4 or the lid body 6, there is a stage in which the disc spring 8 comes into contact with the disc spring receiving surface of the rack guide 4 or the lid body 6 during the deformation process of the disc spring 8 as the rack guide 4 retreats. A triggering device for a rack-and-pinion steering device, characterized in that portions 4a and 6a are provided.