JPS6312046Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rack-and-pinion steering device for an automobile.

The purpose of this invention is to eliminate the problem in which the oil seal of the power cylinder is damaged and oil leaks when the external force from the wheels is transmitted to the steering rod and the steering rod is bent. .

In conventional rack-and-pinion steering systems for automobiles, the oil seal of the power cylinder is directly fixed in the housing. Therefore, when the steering rod is bent due to the force transmitted from the wheels during durability tests, this bending acts directly on the oil seal, causing damage to the oil seal and causing oil leaks. .

The present invention was developed to solve the above problem.The feature is that the oil seal is installed through a seal housing that can be displaced in the radial direction, so that even if the steering rod is bent, the oil seal housing remains The aim is to absorb this through displacement and prevent it from spreading to the oil seal, thereby preventing damage.

Embodiments of the present invention will be described below with reference to the drawings.
In FIG. 1, 10 indicates a housing, and this housing 10 is supported on the frame of an automobile at two support points on the left and right. A steering rod 12 is slidably inserted into the housing 10, and has ball joints 17 and 18 at both ends thereof to be connected to steering wheels.
A rack 1 is attached to the outer circumference of one end of the steering rod 12.
3 is formed, and this rack 13 is connected to the housing 11.
The pinion shaft 14 is rotatably supported on the pinion shaft 14. The pinion shaft 14 is connected to the handle shaft via a servo valve device (not shown). The steering rod 12 is also provided with a piston 15, which is slidably fitted into a power cylinder 16 formed within the housing 10.

The structure of this power cylinder 16 will be explained with reference to FIG. A cylinder tube 24 is fitted into the housing 10 at the power cylinder 16 portion to form a cylinder. A cylinder end 20 is attached to the outer end of the cylinder tube 24 by being fitted into a fitting hole at the end of the housing 10. The steering rod 12 passes through this cylinder end 20, and an oil seal 2 is attached to the penetrating portion.
1 is buried and secured with a circlip 22.

On the other hand, an end cap 23 is attached to the inner end of the cylinder tube 24. The present invention improves the mounting groove structure of the oil seal 25 on the end cap 23 side.

That is, as shown in FIG.
A sleeve-shaped seal housing 27 having a deformable thin wall portion 30 inside is fitted with a slight clearance in the radial direction, one end of which is fitted into the support hole of the housing 10 via an O-ring 31, and the other end is An oil seal 25 is movably supported between the other end of the seal housing 27 and the steering rod 12 inserted through the seal housing 27, and a back-up spring that transmits the displacement of the steering rod 12 to the seal housing 27. 26 is attached. Note that this backup spring 26 is made of a hard material such as sintered metal.

Furthermore, a spring receiver 28 is provided protruding from the outer periphery of the seal housing 27 in order to prevent the seal housing 27 from moving when the cylinder becomes negative pressure and to eliminate play in the axial direction between the end cap 23 and the cylinder tube 24. However, a spring 29 is interposed between the spring receiver 28 and the end surface of the end cap 23 to press the seal housing 27 toward one end and restrain the seal housing 27 from moving in the axial direction. As another embodiment, as shown in FIG. 3, a spring receiver 28a is fitted to the end face of the seal housing 27 facing the end cap 23, and a spring 29 is inserted between the spring receiver 28a and the end face of the end cap 23. may be intervened.

Since the present invention has the above-described structure, the external force F from the wheels acts from both ends of the steering rod 12 as shown in FIG. The steering rod 12 is bent by this external force F, and the bending direction is perpendicular to the axis near the oil seal 25 on the end cap 23 side.
However, according to the present invention, the bending of the steering rod 12 is transmitted to the seal housing 27 via the back-up spring 26, and the seal housing 27 floats in the radial direction while deforming the O-ring by the radial clearance. Alternatively, the thin portion 30 deforms to absorb the bending. As a result, extreme compressive force is not applied to the oil seal 25, thereby preventing damage to the oil seal 25.

As detailed above, the present invention involves inserting a sleeve-shaped seal housing having a thin wall in the center into the housing, forming a clearance in the radial direction at one end of the seal housing, and pressing the seal housing in the direction of the one end with a spring. An oil seal and a back-up spring are fitted on the inner periphery of the other end of the seal housing and slidably contact the steering rod by fitting into the support hole of the housing to restrict axial movement and swingably supporting the other end of the seal housing. Since the seal housing is equipped with a seal housing, the seal housing can tilt or float in the radial direction extremely smoothly within the housing without experiencing sliding resistance, thereby following the deformation of the steering rod. The oil seal can be displaced, and since the seal housing itself can be elastically deformed in its thin walled portion, combined with the floating action, it can accommodate large deformations of the steering rod, and as a result, the oil seal It has the advantage of being able to reliably prevent damage to the seal and maintain proper sealing function at all times.

[Brief explanation of drawings]

FIG. 1 is a partially sectional plan view of the device of the present invention, FIG. 2 is an enlarged sectional view of the main part of the power cylinder portion, and FIG. 3 is an enlarged sectional view of the main part showing another embodiment. 10...Housing, 12...Steering rod, 13...Rack, 14...Pinion shaft, 1
5... Piston, 16... Power cylinder, 20
...Cylinder end, 21 ...Oil seal, 2
3...End cap, 24...Cylinder tube, 25...Oil seal, 26...Backup spring, 27...Seal housing, 29...
spring.

Claims (1)

[Scope of utility model registration request] A housing, a cylinder formed in the housing, a piston slidably fitted in the cylinder, a steering rod that is integral with the piston and passes through the housing, and the steering rod. In a rack-and-pinion type steering device comprising a pinion shaft that meshes with a rack formed in a rack, a sleeve-shaped seal housing having a thin walled portion at the center is inserted into the housing with a clearance formed in the radial direction. One end of the seal housing is fitted into a support hole of the housing to swingably support the other end, and the seal housing is pressed against the one end with a spring to restrain axial movement. A steering device for an automobile comprising an oil seal and a back-up spring attached to the inner periphery of the other end for slidingly contacting the steering rod.