JPH0110307Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cylinder device for a steering gear used to assist the power of the steering gear.

Generally, in this type of steering device, when the steering rod is bent in the radial direction, this bending acts on the sealing member that seals both ends of the cylinder device, damaging the sealing member and causing oil leakage. There is a problem.

For this reason, conventionally, the seal member is mounted in a radially deformable seal housing, and the bending of the steering rod is absorbed by the deformation of the seal housing, thereby preventing excessive compressive force from acting on the seal member. This prevents damage.

However, in order to provide the seal housing with a deformation function in such conventional devices, it is necessary to use a seal housing with a thin wall and a large axial length, and therefore, depending on the installation space, there are restrictions on the installation of the seal housing. I had something to accept.

The present invention was developed to eliminate these drawbacks of the conventional design, and its purpose is to absorb the bending of the steering rod by floating the seal housing, which is supported with a radial clearance. This is to prevent damage to the seal member.

Another object of the present invention is to shorten the axial length of the seal housing so that the installation space is not limited.

Embodiments of the present invention will be described below based on the drawings. 11 is a housing fixed to the automobile frame at two support points; 12 is a side case; 14
These housing 11 and side case 1
This is a cylinder in which two cylinders are fitted and further integrally connected by a pin 13. A steering rod 15 is slidably inserted into the housing 11, and both ends of the steering rod 15 are connected to ball joints 16,
It is connected to steering wheels (not shown) via 17.
A rack 1 is attached to the outer circumference of one end of the steering rod 15.
8 is formed, and this rack 18 is connected to the housing 11.
The pinion shaft 19 is rotatably supported on the pinion shaft 19. The pinion shaft 19 is connected to the handle shaft via a servo valve device (not shown). A piston 20 is also formed on the steering rod 15, and the piston 20 is slidably fitted into a cylinder 14 provided in the housing 11.

The essential part of the present invention lies in the configuration of the seal portion at the end of the cylinder 14 in the steering device having such a configuration.

FIG. 2 shows details of the seal portion, and a sleeve-shaped seal housing 25 is housed inside the cylinder 14. The steering rod 15 is inserted into the center hole 40 of the seal housing 25, and a projection 26 is provided at the center of the outer peripheral surface.
is formed. A radial clearance δ1 is ensured between the projection 26 and the inner circumferential surface of the cylinder 14, allowing the seal housing 25 to float in the radial direction. Note that a sealing ring 28 for preventing oil leakage from the cylinder 14 is housed in an annular groove 27 formed in this protrusion 26, but this sealing ring 28 is made of an elastic material such as rubber. , without impairing the floating action of the seal housing 25.

A mounting hole 2 is provided on the inner periphery of one end of the seal housing 25.
9 is formed in the mounting hole 29, and a seal member 30 and a back-up spring 31, which are in slidable contact with the steering rod 15, are mounted in the mounting hole 29. A fitting hole 32 is formed on the inner periphery of the other end of the seal housing 25, and a supporting portion 33 protruding from the housing 11 is loosely fitted into the fitting hole 32. A radial clearance δ2 is ensured between the fitting hole 32 and the support portion 33, allowing the seal housing 25 to float in the radial direction. A pin hole 34 is formed in the support portion 33,
An engagement pin 35 is press-fitted into the pin hole 34 and held therein. This engagement pin 35 is loosely fitted into a pin hole 36 of the seal housing 25 to prevent the seal housing 25 from coming off from the support portion 33. Note that this engagement pin 35 has a spherical tip,
In addition, since it fits into the pin hole 36 with a slight clearance, the floating function of the seal housing 25 is not impaired.

In the above configuration, when an external force F from the wheels acts as shown in FIG.
5 is deformed in the radial direction, but according to the present invention, the seal housing 25 also floats in the radial direction following the radial deformation of the steering rod 15. An increase in sliding resistance and further damage to the seal member 30 can be prevented.

As detailed above, in the present invention, the seal housing is supported with a radial clearance relative to the housing support, and the floating function of the seal housing absorbs the radial bending of the steering rod. With this configuration, no unreasonable compressive force is applied to the seal member, and it is possible to prevent an increase in sliding resistance and damage to the seal member.

In addition, since the present invention has a structure in which the seal housing is supported by floating on the support portion of the housing, the axial length can be shortened compared to a structure in which a flexible seal housing is elastically deformed. It has the advantage that it can be easily incorporated into a relatively limited space.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a rack and pinion type steering device to which the present invention is applied, and FIG. 2 is a cross-sectional view of a cylinder device showing an embodiment of the present invention. 11...Housing, 14...Cylinder, 15
... Steering rod, 20 ... Piston, 2
5... Seal housing, 30... Seal member,
35...Engagement pin.

Claims (1)

[Scope of utility model registration request] A cylinder device for a steering gear, in which a piston is formed on a steering rod slidably supported by a housing, and the piston is slidably fitted into a cylinder provided in the housing, wherein the cylinder includes a A seal housing, into which the steering rod is inserted, is installed with a radial clearance secured between the inner periphery of the cylinder, and a seal member that slides into contact with the steering rod is fitted to one end of the seal housing. A cylinder device for a steering gear, characterized in that the other end of the seal housing is fitted into the support portion of the housing so as to be able to float while ensuring a radial clearance, and is prevented from coming off by an engagement pin.