JPS6339166Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rack end knocking noise prevention device for a rack and pinion type steering mechanism of a vehicle.

More specifically, an elastic member having non-linear spring characteristics is interposed in the rack stopper of a rack and pinion type steering gear box to prevent the knocking noise that is generated due to the collision between the rack stopper and the rack end at the end of the rack stroke, such as during downtime. The present invention relates to a device that does the following.

The rack and pinion type steering mechanism rotates the pinion by rotating the steering wheel of the steering shaft, moves the rack that meshes with the pinion to the left and right, and operates the left and right steering wheels via the rack. Steering by.

By the way, when the steering angle is turned all the way at a high speed when the steering wheel is stationary (steering while stopped), and the rack moves to the stroke end of the rack, the rack end will collide with the stopper at either end of the steering gear box. Since this stopper part is a rigid body and the rack end part is a rigid body, a collision sound is generated, which is a so-called hitting sound. Along with this hitting sound, the impact is transmitted to the driver's hand, which is also unfavorable in terms of steering feel.

The present inventor has devised the present invention in view of the above-mentioned problems in the rack and pinion type steering mechanism, and to effectively solve the problems.

The object of the present invention is to provide an elastic member having non-linear spring characteristics at the end stopper of the steering gear box in a rack and pinion type steering mechanism, so that when the rack end collides with the elastic member, this impact is absorbed. It absorbs relaxation, suppresses the occurrence of hitting sounds, and also prevents the collision noise between the elastic member and the rack end itself due to the characteristics of this type of spring.Furthermore, the deformation of the elastic member is limited to a predetermined position to generate rigidity, and the elastic member To provide a hammering sound prevention device which can improve the resistance to the noise and ensure the hammering sound prevention effect over a long period of time.

Next, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 is a cross-sectional view of the main parts of a rack and pinion type steering gear box. 1 is a case forming the gear box, and this case 1 extends in the left-right direction, and a rack 2 is installed inside the middle chamber. has been done. Rack 2 is movable in the axial direction of case 1,
Teeth 3 are carved into a part of this. The tip of the shaft 4 is inserted into the box portion 1a of the case 1 so as to intersect with the rack 2.
A gear 5 that meshes with the teeth of the rack 2 is provided at the tip of the shaft 4, and bearings 6,
7 is supported. The shaft 4 is rotated by a steering wheel (not shown), and the rack 2, which is engaged with the gear 5, is moved to the right or left in the figure. Both left and right ends (both ends in the axial direction) of the rack 2 are connected to a knuckle arm of a steering wheel (not shown) via a joint 8, and although only the right end is shown in the figure, the left end is similarly configured, and 9 in the figure is a dust They are boots.

Flange-shaped stopper end members 10 are fixedly installed at both ends of the rack 2, and at the opposite end of the gearbox case 1,
A recess 11 is provided in which the end member 10 fits loosely. An elastic member 12 having nonlinear spring characteristics is interposed within this recess 11 . The characteristics of the elastic member 12 as shown in FIG. 6 are obtained by the nonlinear spring characteristics.

In other words, in the graph of Fig. 6, if the horizontal axis is the displacement amount and the vertical axis is the load, a linear spring will have a line A, but a nonlinear spring will have a characteristic like a line B, that is, it will be soft at the beginning of the load. , becomes hard as the load increases, rises from a predetermined displacement l ₀ , that is, point C, and thereafter acts as a rigid body.

FIGS. 2 to 5 show specific embodiments of the elastic member.

First, the type shown in FIG. 2 uses a rubber member 13 as an elastic body, and this is inserted deep into the recess 11 in a ring shape. A collar-shaped holder 14 is interposed between the inner diameter part of the rubber member 13 and the outer circumference of the rack 2, and the flange part 14a of the holder 14 is located on the outer side of the rubber member 13 and is slidably fitted into the inner circumference of the recess 11. has been done. This holder 14 may be made of metal or hard synthetic resin.

In this embodiment, the rack 2 moves to the left, the flange-like end member 10 abuts against the holder 14, the rubber member 13 is compressed to absorb and absorb the impact, and the holder 14 finally touches the end face of the recess 11. Any further movement will be blocked. In this process, impact sounds, that is, hitting sounds, are absorbed and suppressed.

The embodiment shown in FIG. 3 has a disc spring 114 and a rubber member 1.
13, the recess 11 formed at the end of the case 1 is made into two stages 11a and 11b with a large diameter and a small diameter, and a ring-shaped rubber member 11 is formed in the small diameter part 11b at the back.
3 is fitted so as to surround the rack 2, and a hole 114a is formed in the center of the outer large diameter portion 11a of the disc spring 1.
14 is compressed and the rack 2 passes through the hole 114a. A central portion 114b including the hole 114a bulges outward in the axial direction, and a corresponding portion of the rubber member 113 is in contact with the inner side of the central portion 114b.

The embodiment shown in FIG. 4 has a bulge 2 inside the recess 11.
Two disc springs 214, 214 are compressed so that 14b, 214b face each other, and the rack 2 is passed through a hole 214a provided in the center of the bulging portion 214b.
and the outer one 214 of the disc springs 214, 214
A faces the easy end portion 10.

The embodiment shown in FIG. 5 uses a wave washer 314 instead of the above. That is, the wave washer 314 is inserted into the recess 11, and the rack 2 is passed through the center hole 314a of the wave washer 314, and the center hole 314a and the peripheral portion 314b of the wave washer 314 are curved in a concave shape toward the end face of the recess 11, and further, the outer peripheral portion 314c of the wave washer 314 is curved concavely in the direction of the end surface of the recess 11. is curved outward.

In each of the above embodiments, the holder 14, the disc spring 11
4, 214A, the means for locking the wave washer 314 is not shown, but this is done by inserting and locking a circlip into the peripheral wall of the recess.

As is clear from the above, according to the present invention, since an elastic member having non-linear spring characteristics is interposed at the end of the gearbox, the rack end and the gearbox end can be easily rotated by fast steering operation at the time of stationary operation, and by operation up to the limit. Even if the parts collide, the impact is relaxed and absorbed by the elastic member, effectively suppressing and reducing the occurrence of hammering noise, and after the elastic member has been displaced by a predetermined amount, the deformation is almost maintained at the predetermined position. Since it abuts against the rack end in a limited manner, there is no risk of permanent deformation even when a large load is applied, thus improving durability and ensuring long-term knocking sound prevention effects. In addition, a suitable sense of stopping can be obtained at the maximum stroke of the rack, and damage to the elastic member etc. due to forced steering operation can be prevented.

In addition, the structure is simple, as it is sufficient to form a recess at the end of the gearbox and insert the elastic member into the recess.
Moreover, the effect of preventing hitting noise can be obtained at low cost.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view of the main parts of a rack and pinion type steering mechanism, and FIGS. 2 to 5 are explanatory sectional views showing each embodiment of the elastic member. 6 are graphs explaining the nonlinear spring characteristics. In the drawing, 1 is the gearbox case, 2 is the rack, 4 is the pinion, 10 is the rack end, 12,
13, 113, 114, 214, and 314 are elastic members.

Claims (1)

[Scope of utility model registration request] In a rack and pinion type vehicle steering device, a recess is formed at both ends of the steering gear box as a rack stopper, and the recess has a nonlinear spring characteristic within a predetermined amount of displacement, and the deformation occurs after the predetermined amount of displacement. What is claimed is: 1. A steering rack end knocking sound prevention device comprising: an elastic member that abuts against the rack end while substantially limiting the steering rack end at a predetermined position;