JPH055302Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a front fork for a two-wheeled vehicle, and more specifically, to an improvement in the mounting portion of a seal case that houses an oil seal in a front fork.

[Conventional technology]

In the conventional seal case mounting means for this type of front fork, a threaded portion is formed on the outer circumferential surface of the tip region of the outer tube, and the seal case containing the oil seal is placed over the tip of the tube. The in-cylinder threaded portion and the threaded portion were screwed together and tightened to assemble them into one piece.

In addition, in order to prevent loosening of the screw tightening due to vibrations during running of the mounting wheel under such assembly, an adhesive may be applied to the threaded portion during screwing. Alternatively, measures to prevent loosening have been taken, such as partially deforming the threaded portion of the seal case by means such as punching from the outer periphery of the seal case after tightening the thread.

[The problem that the idea aims to solve]

However, the conventional seal case mounting configuration consisting of the above-mentioned means not only requires screws and thread processing for screwing and fastening the outer tube and seal case, but also requires measures to prevent loosening after fastening, which increases the number of processing steps and assembly steps, and there is still room for improvement in terms of reducing manufacturing costs.

Therefore, in view of the above-mentioned drawbacks of the conventional device, the present invention proposes a front fork developed with the intention of stabilizing seal case assembly and reducing costs.

[Means to solve the problem]

That is, according to the present invention, one end of the seal case attached to the tip of the outer tube of the front fork is made thin.

After this seal case is placed over the outer tube, the thin end is plastically deformed so as to come into pressure contact with the outer peripheral surface of the outer tube.

[Effect]

As a result, the plastically deformed end of the seal case has a structure in which the inner wall of the entire circumference is in close contact with the outer circumferential surface of the outer tube, and has both the fixing function of the conventional device by the threaded part and the loosening prevention function by caulking, etc. It acts as.

〔Example〕

Next, embodiments of the present invention will be described.

FIG. 1 is a partially cutaway side view of the main parts of an embodiment of the present invention, in which a bearing 3 is arranged at the tip of an outer tube 1 into which an inner tube 2 is slidably fitted, and an oil seal 4 is attached to a washer 5. A seal case 7 which is sandwiched and housed by a stopper ring 6 and a seal case 7 is fitted under a sealing O-ring 8, and furthermore, a dust seal 9 is placed over the open end of the case 7.

The fitting end of the seal case 7, which is made of a cylindrical metal ring, is thinly formed by cutting off the ring thickness, and after fitting to the outer tube 1,
The end portion is plastically deformed by caulking so as to come into close contact with the outer periphery of the tube 1.

In this case, it is effective in preventing the case 7 from falling off after assembly that the outer circumferential surface of the outer tube 1, which the plastically deformed portion of the seal case 7 is in close contact with, is an inclined surface that hangs from the large diameter portion at its tip. By forming this inclined surface on the rough surface 10, such as a knurled surface, as shown in the second figure, the circumferential movement of the case 7 can be achieved by the close contact caused by the plastic deformation. This makes it possible to hold the case more firmly.

[Effect of idea]

As described above, according to the front fork of the present invention, one end of the seal case is formed thinly, and this thin end is plastically deformed while being fitted with the outer tube, so that it comes into close contact with the outer periphery of the tube. First, there is no need for screw processing or measures to prevent loosening for assembling the seal case, which can significantly reduce manufacturing costs, and also eliminate the need for the external part of the seal case to prevent loosening in conventional devices. Instead of regular caulking, the entire circumference of the thin end portion is uniformly deformed, so there is less risk of annular deformation of the assembled seal case itself, and the sealing effect due to annular deformation that tends to occur when partially caulking is reduced. In addition to being able to assemble the seal case more stably without worrying about deterioration, by processing the outer circumferential surface of the outer tube, which the thin end of the case comes into close contact with, into a rough surface such as a knurled shape,
If the deformed inner surface is bitten into the plastic surface during the plastic deformation process, it is possible to firmly fix the case in the inner circumferential direction. The front fork of the present invention also has secondary effects such as being able to be attached, and this effect is extremely noticeable when put into practical use.

[Brief explanation of the drawing]

FIG. 1 is a side view showing an embodiment of the front fork of the present invention with a part of the main part cut away, and FIG. 2 is a side view of the main part showing an example of an outer tube in the front fork of the present invention. 1... Outer tube, 2... Inner tube, 4... Oil seal, 7... Seal case.

Claims (1)

[Scope of utility model registration request] In a seal case for assembling an oil seal to the tip of an outer tube into which an inner tube can be freely inserted and removed, one end of the seal case is formed thin, and one end of the thin wall is plastically attached to the outer peripheral surface of the inserted outer tube. The front fork is stuck due to deformation.