JPH0227229Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a rod guide for a dual-tube shock absorber.

The rod guide in the conventional shock absorber of this type is composed of a single component, and it is difficult to compensate for the deflection of the piston rod during operation and the inclination caused by assembly errors.

For this reason, conventional models have embedded ball bearings as rod guides that revolve around the piston rod, but the spherical part rotates freely, making assembly difficult, and they are generally expensive and impractical. It was hot.

Furthermore, in order to maintain the damping force characteristics, it is more effective to have a smaller gap between the piston rod and the rod guide, but for the reasons mentioned above, it has been difficult to maintain the gap below a certain level in terms of processing and assembly.

Furthermore, conventional rod guides require a special oil leakage prevention mechanism such as highly precise machining of the contact portion with the cylinder or interposition of a sealing material.

In view of the current situation as described above, the present invention has a simple structure, properly and smoothly guides the piston rod, prevents oil leakage (strengthens the sealing function), facilitates processing and assembly work, and reduces the inclination of the piston rod to some extent. The object of the present invention is to provide a rod guide for a shock absorber that can automatically correct assembling accuracy (without worrying about damaging the inner wall of the cylinder, etc.) and that can be controlled to a predetermined amount or more.

For this reason, the present invention includes a spherical bearing section with a spherical outer circumference of the rod guide that guides the piston rod of the dual-tube shock absorber, an upper support section that supports approximately the upper half of the spherical bearing section, and a spherical bearing section that supports approximately the upper half of the spherical bearing section. It consists of three parts, a lower support part that supports approximately the lower half, and a protrusion band around the outer periphery of the spherical bearing part, and the protrusion on the inner periphery of the abutting part between the upper support part and the lower support part. A recessed groove 9 is provided in which the ridge is loosely fitted with a certain margin, and the lower support part is molded from a flexible material such as hard rubber or synthetic resin, and an annular recessed groove is provided at the lower edge. It was drilled and its cross section was formed into a bifurcated shape.

The gist of the present invention will be explained below based on the embodiments shown in the drawings.

FIG. 1 is a partially cutaway front view showing an embodiment of the rod guide portion of a shock absorber based on the present invention, and FIG. 2 is an enlarged sectional view of the lower support portion of FIG. 1.

In the drawings, 1 is a piston rod, 2 is a cylinder, 3 is an outer cylinder, and 4 is a rod guide, which is composed of a spherical bearing part 5, an upper support part 6, and a lower support part 7, and the spherical bearing part 5 has a spherical outer circumference. For example, it is made of a steel ball with an inner surface treated, a ceramic material, plastic, etc., and a protruding band 8 is provided around the outer periphery of the spherical surface, and is loosely fitted into a groove 9 to be described later. .

The upper support part 6 is made of, for example, a ferrous sintered alloy, and closes the upper opening 5a of the cylinder 2 and the outer tube 3 together with the lower support part 7 as shown in the figure.

The lower support part 7 is made of a flexible material such as hard rubber, tony metal, or pelprene, has an annular groove 10 on its lower surface, and has a bifurcated cross section. The internal pressure presses the forked portions 10a and 10b of the concave groove 10 to the left and right as shown by the arrows, and presses the cylinder 2 and the spherical bearing portion 5 to prevent oil leakage.

11 is an oil return hole provided in a part of the upper support portion 6, and 12 is a return groove communicating with the return hole 11.

The upper part of the outer cylinder 3 is sealed by a core metal 13 whose outer periphery is molded with rubber and an oil seal 14, and furthermore, the upper part of the outer cylinder 3 is apertured 15 for dimensional accuracy.

The rod guide of the present invention with the above structure consists of three parts: the spherical bearing part 5, the upper support part 6, and the lower support part 7. The spherical surface is recessed, and an annular groove 10 is formed facing the protruding band 8 and into which it is loosely fitted. Since it is formed wide enough to accommodate the piston rod 1, the operation of the piston rod 1 will not be hindered at all.

In addition, since the lower support part 7 is made of a flexible material as described above, it has elasticity that can cope with external forces. Due to the internal pressure of the cylinder 2 and the spherical bearing 5,
The sealing function can be further improved.

As mentioned above, since the rod guide 4 of the present invention is molded from three parts 5, 6, and 7,
It becomes possible to select a desired material corresponding to each function, and it becomes easy to mold the three parts separately with a mold, so that it can be provided at a correspondingly low cost.

Furthermore, in this embodiment, although the protruding band 8 and the groove 9 are provided with a certain margin, the upper and lower supporting parts 6,
It goes without saying that depending on the material of the piston rods 7, the spherical bearing portion 5 can be adapted to the inclination of the piston rod 1 even if they are connected in a sliding fit state.

As mentioned above, the rod guide of the shock absorber of the present invention is constructed from three parts: the spherical bearing part, the upper support part, and the lower support part, so that the piston rod can be guided properly and smoothly, and oil leakage can be prevented (sealed). This makes processing and assembly easier.

More specifically, first, a protruding band is placed around the outer periphery of the spherical bearing part, and the protruding band is provided with a certain amount of slack around the inner periphery of the abutment area between the upper support part and the lower support part. By providing a groove for fitting, the piston rod is allowed to tilt to a certain extent, but since it is possible to reliably restrict tilting beyond a predetermined amount, there is no risk of damaging the inner wall of the cylinder, etc.

Next, the lower support part is molded from a flexible material such as hard rubber or synthetic resin, and an annular groove is bored in the lower edge and its cross section is bifurcated to prevent oil leakage. The sealing function can be strengthened in conjunction with the pressing action by internal pressure.

By adopting the configuration of the present invention as described above, the spherical bearing section receiving the cylinder internal pressure,
It also has the remarkable effect of automatically correcting assembly accuracy.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the rod guide of a shock absorber based on the present invention, and FIG. 2 is an enlarged longitudinal sectional view showing a part of the lower support member of FIG. 1... Piston rod, 2... Cylinder, 3...
... Outer cylinder, 4 ... Rod guide, 5 ... Spherical bearing part, 5a ... Opening, 6 ... Upper support part, 7 ... Lower support part, 8 ... Protruding band, 9 ... Concave groove, 10 ... …
Annular groove, 10a, 10b...forked part, 11...
Oil return hole, 12...Return groove, 13...Core metal, 14...Oil seal, 15...Aperture.

Claims (1)

[Claims for Utility Model Registration] A spherical bearing portion with a spherical outer circumference of a rod guide that guides a piston rod of a dual-tube shock absorber, an upper support portion that supports approximately the upper half of the spherical bearing portion, and a spherical bearing portion. It consists of three parts: a lower support part that supports approximately the lower half of the spherical bearing part, and a protruding band surrounds the outer periphery of the spherical bearing part, and a ridge band is formed on the inner periphery of the abutting part between the upper support part and the lower support part. A recessed groove is provided in which the protruding band is loosely fitted with a certain margin, and the lower support portion is molded from a flexible material such as hard rubber or synthetic resin, and an annular recessed groove is provided at the lower edge. A rod guide for a shock absorber, characterized in that the rod guide is bored and has a bifurcated cross section.