JPH0223519Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION This invention relates to an improved motorcycle rear fork that is easier to manufacture and reduces manufacturing costs.

Generally, in a motorcycle, a shaft cylinder is welded to the front end of the hawk pieces of the left and right rear fork, the shaft cylinder is attached to the vehicle body with a support shaft, and a cushion unit is connected between the rear fork and the upper part of the vehicle body. is designed to swing around a support shaft for cushioning, and the axle of the rear wheel is fastened to the rear ends of the left and right fork pieces. As shown in FIGS. 1 and 2, the front ends of the left and right fork pieces A of the rear fork have their top and bottom surfaces slightly inwardly tapered, and their left and right sides curved.
The sides of the shaft cylinder B are aligned and connected by welding. In this case, the hawk piece A is made of a rectangular light alloy pipe material to reduce weight, and the shaft tube B is made of a light alloy cylindrical pipe material cut to an appropriate length. Further, it is troublesome to process the front end of the fork piece A so as to match the side surface of the shaft cylinder B, and the welding part is also a curved welding part, which is troublesome and takes time to manufacture, resulting in high cost.

This idea is an improvement based on these points.
The present invention will be described below with reference to an embodiment shown in FIGS. 3 and 4.

The shaft tube 1 is integrally formed on one side thereof with an overhanging flesh part 2 having the same square cross-sectional shape as the cross-sectional shape of the hollow portion of the left and right fork pieces 3 each having a rectangular pipe shape. This can be done by providing a barrel mold with an overhanging flesh portion 2, drawing a material into a pipe shape, and cutting the material to the length of the barrel 1. The left and right hawk pieces 3 are made of light alloy pipe material with a square cross section.
Insert and fit the overhanging flesh part 2 of the shaft cylinder 1 into the front end of the fork piece 3, and the front end of the fork piece 3 and the overhanging flesh part 2
The shaft cylinder 1 is connected to the front end of the fork piece 3 by welding 4. The left and right fork pieces 3 are connected at the front by a bridge piece, and an axle fitting is welded to the rear end of the fork piece 3.

Therefore, the shaft cylinder 1 can be made by cutting a pipe material with a deformed cross section, integrally provided with an overhanging meat part 2 on one side, into the required length, and thereby saving time and effort. Not needed. Then, the overhanging flesh part 2 of the shaft cylinder 1 is inserted into the front ends of the left and right fork pieces 3, and they are fitted and welded, so that the front parts of the fork pieces 3 are
The cut shape can be simply left as it is, and the welding lines can all be straight, which simplifies the work and greatly reduces manufacturing costs.

As explained above, this invention has an overhanging part having the same square cross-sectional shape as the hollow part of the hawk piece on one side of the shaft cylinder, and an overhanging part at the front end of the hawk piece of square pipe material. Since we connected the barrel to the front end of the hawk piece by inserting and welding it, the front end of the hawk piece can simply be cut.
The lines to be welded are also straight, which simplifies processing time and welding time, resulting in a significant reduction in manufacturing costs. Since the overhanging flesh part of the shaft cylinder is inserted and fitted into the front end of the fork piece, the strength is sufficient and the rigidity can be increased. It also has good melting properties during welding work.

[Brief explanation of the drawing]

Fig. 1 and Fig. 2 show a conventional example, Fig. 1 is a perspective view, Fig. 2 is an enlarged vertical sectional side view of the part indicated by the arrow X in Fig. 1, and Fig. 3 and Fig. 4 are one embodiment of the present invention. An example is shown, and FIG. 3 is a perspective view of the main part, and FIG. 4 is a longitudinal sectional side view of the main part. 1... shaft cylinder, 2... overhanging meat part, 3... hawk piece, 4... welding.

Claims (1)

[Scope of utility model registration request] In the rear fork of a motorcycle, a shaft tube is welded to the front end of each of the left and right fork pieces formed by a pipe with a rectangular cross section, and one side of the shaft tube has a rectangular cross-sectional shape that is the same as the cross-sectional shape of the hollow part of the fork piece. A motorcycle characterized in that an overhanging meat part of the shaft cylinder is integrally provided, the overhanging meat part of the shaft cylinder is fitted into the front end of the fork piece, and the outer peripheral part of the overhanging meat part is welded to the front end of the fork piece. After Hawk.