JPH0121106Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a rack and pinion type steering device,
In particular, the center shaft where the track rod that transmits steering force to the running wheels is connected to the center of the rack shaft.
This invention relates to a take-off type rack and pinion steering device.

Generally, in a center take-off type rack and pinion steering device, the track rods that transmit the reciprocating motion of the rack shaft to turn the running wheels are not connected to both end faces of the rack shaft, but are placed in the middle of the rack shaft.
The rack housing is connected by bolts, etc. through long holes formed in the rack housing.In order to restrict the axial movement end of the rack shaft, a pair of bolts are used to connect the rack rod to the rack shaft. A stopper member is fixed, and the end face of the stopper member interferes with the end face of the elongated hole of the rack housing to stop the rack shaft.

In such conventional steering devices, the rack housing is made of metal, and the stopper member is made of either metal or resin. If the stopper member is made of metal, it has sufficient strength and therefore has a reliable function of limiting the stroke, but this is not preferable because it generates a loud collision noise between metals. Further, in the case of a stopper made of resin, although it has the effect of reducing collision noise, it has the disadvantage that sufficient reliability cannot be obtained in the stroke limiting function.

The present invention was devised in view of the above-mentioned drawbacks, and the present invention absorbs the impact caused by the interference between the stopper member and the end face of the elongated hole of the housing by the elastic force of the leaf spring provided on the stopper member. The purpose of this device is to provide a rack and pinion type steering device that can reduce collision noise while maintaining the reliability of the stroke limiting function. comprising a stopper member that interferes with a stopper portion of the rack housing to regulate the stroke end of the rack shaft;
This stopper member is provided with a concave portion whose inner side is widened on its interference end surface, and both ends of a curved leaf spring are locked in the widened portion of the concave portion. The curved protruding surface is arranged to protrude outward from the interference end surface.

Hereinafter, the present invention will be explained based on illustrated embodiments. FIG. 1 shows a center take-off type rack and pinion type steering device, in which rack teeth 3 are formed at one end of a rack shaft 2 slidably supported in a rack housing 1, and rack teeth 3 are formed at the other end. A pair of bolts 4 and 5 are screwed together and protrude from an elongated hole 6 provided in the rack housing. This bolt 4,
A track rod (not shown) extending along the axial direction of the rack shaft 2 is connected to each of the rack shafts 5, and a pair of steering wheels connected to the other end of these track rods are connected to each other as the rack shaft 2 reciprocates. The vehicle is turned either left or right. A pinion 7 rotated by a steering handle (not shown) is meshed with the rack teeth 3, and rotation of the steering handle is controlled by the pinion 7 and the rack shaft 2.
A conventionally known rack and pinion type steering device is configured, which transmits the deviation of the steered wheels in the left and right direction via the steering wheel.

The elongated hole 6 of the rack housing is connected to the rack shaft 2.
The outer periphery of the rack housing 1 at this portion is provided with a boot 8 made of a flexible material to prevent foreign matter from entering the housing. covered.
A stopper member 9 is fixed on the rack shaft 2 by the pair of bolts 4 and 5.
The amount of movement in the left-right direction is regulated by the stopper member 9 interfering with the axial end surfaces 6a, 6a of the elongated hole 6.

The structure of this stopper portion will be explained in detail. The main body 10 of the stopper member 9 is made of a metal material, and plate springs 11, 11 are attached to the lower portions of both longitudinal end surfaces 10a. As shown in FIGS. 2 and 3, these leaf springs 11, 11 have a shape in which a plate made of metal or the like is curved into an arc shape, and is approximately 1/2 the height h of the metal body 10. It has a height h'. On the other hand, a concave portion 12 is provided at approximately the lower half of the both end surfaces 10a, 10a of the metal body 10.
is formed. This concave part 12 has an inner part widened to form 12a, 12a, and inward flanges 12b, 12b that are connected to this,
Further, the outer surfaces of the flanges 12b, 12b coincide with the end surface 10a. The leaf spring 11 is disposed within the recessed portion 12 with the curved convex surface 11a facing the elongated hole end surface 6a of the housing 1, and both ends 11b, 11b are located within the inward flanges 12b, 12b. The metal body 10 is secured to the expanded width portion of the metal body 10 to prevent it from falling off.
With the leaf spring 11 disposed within the concave portion 12 in this manner, the center portion of the convex side surface 11a of the leaf spring 11 protrudes outward from the end surface 10a of the main body 10.

Since the stopper member is configured as described above, when the steering angle is increased, the rack shaft 2 is moved in the axial direction via the pinion 7, and the stopper member 9 interferes with the end surfaces 6a, 6a of the elongated hole. When limiting the stroke by
Only the center portion of the convex surface 11a of the leaf spring 11 has an end surface 6
a, 6a, so no collision noise is generated. Also, when a medium to heavy load is applied, the central part of the convex surface 11a of the leaf spring 11 first comes into contact with the end surfaces 6a, 6a, and then this leaf spring 11 gradually The impact sound is eliminated by reducing the collision speed between the stopper member 9 and the housing 1, and finally the upper end surface 1 of the metal body 10
Since the stroke limiting function is performed by interfering with the end surfaces 6a, 6a of the elongated hole, the two requirements of highly reliable stroke limiting function and prevention of collision noise can be achieved at the same time.

4 and 5 show other examples of the leaf spring 11 attached to the metal body 10 of the stopper member 9. FIG. Expanded width portion both ends 11
b, 11b are formed in a planar shape to enable smooth operation. In FIG. The central portion of the convex surface 11a that comes into contact with is also made flat, thereby reducing the surface pressure at the time of contact.

As described above, according to the present invention, in addition to satisfying the stroke limiting function, there is no collision noise during full stroke, and the leaf spring is simply inserted and locked in the recessed part of the end face of the stopper member. It is possible to provide a steering device that requires a simple structure and has good workability during assembly.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention, FIG. 2 is an explanatory view of the housing and stopper member seen from below, and FIGS. 3 a and b are perspective views showing the leaf spring and the metal body, respectively. Figure 4 a, b and Figure 5 a,
b shows another embodiment of the leaf spring, each figure a is a perspective view, and the figure b is a plan view. 1...Rack housing, 2...Rack shaft, 6
a... Stopper part of housing (axial end surface of housing elongated hole), 9... Stopper member, 11...
leaf spring.

Claims (1)

[Scope of utility model registration request] A stopper member is fixedly attached to the rack shaft and interferes with the stopper portion of the rack housing to restrict the stroke end of the rack shaft. It is characterized in that both ends of a curved leaf spring are secured to the widened portion in the recessed part, and the curved protruding surface of the leaf spring is arranged to protrude outward from the interference end surface. Rack and pinion type steering device.