JPH0443033B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement of a rear fork for a motorcycle.

The fork pipe that constitutes the rear fork of a motorcycle is formed into a rectangular shape, and the rear axle shaft is supported at its terminal end so that it can be adjusted in the longitudinal direction. Fixing the processed end piece by welding,
The chain adjuster was slidably housed in the rectangular space at the end, and the end was crushed.

However, if the end piece is provided inside the terminal end, the bearing surface of the axle nut that is fastened to the axle shaft will be inside the outer surface of the fork pipe, so the axle shaft can be shortened, but the end piece is separately machined. This increases the cost, and if the chain adjuster is housed in the rectangular space at the end, the width (thickness) of the chain adjuster increases.
Due to the large size, the weight increased, and the axle shaft could not be shortened, and it was difficult to crush the end of the pipe with square fork pipes, among other limitations.

The present invention has been made to solve the above-mentioned conventional problems all at once.The purpose of the present invention is to shorten the rear wheel axle axis by making the terminal end of the rectangular fork pipe more compact, and to reduce the length of the chain axle. It is an automatic machine that achieves weight reduction by reducing the width (thickness) of the star, reduces costs by not requiring separately processed parts, and is also good in terms of manufacturing because it does not require difficult crushing. We provide rear forks for motorcycles.

In order to achieve such an object, the rear fork of a motorcycle according to the present invention is formed by extruding a square fork pipe whose end part is divided into left and right chambers by a partition wall, and the chamber outside the end part is opened to the outside. At the same time, a chain adjuster is slidably housed in the inner chamber to support the rear wheel axle shaft so as to be freely adjustable in the longitudinal direction, and a partition wall and a chain adjuster are installed from the outer chamber to the end of the rear wheel axle shaft. The gist is that the axle nut was fastened through the star and the inner wall.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a perspective view of the rear fork, FIG. 2 is a plan view showing the axle shaft support structure at the end of the rectangular fork pipe, and FIG. 3 is a side view of the same without showing the nut.

As shown in FIG. 1, the left and right fork pipes 2 and 3 of the rear fork 1 are square pipes, and the both square fork pipes 2 and 3 are connected at the front by a cross member 4. This double square fork pipe 2,
Since the structure of No. 3 is similar, the structure of only one will be explained below.

In the present invention, the terminal end 5 of the square fork pipe 2
As shown in FIG. 2 and FIG. 4, which is a cross-sectional view taken along the line -, a partition wall 6 is integrally molded in the left and right center portions of the inside.
It is divided into left and right chambers 7 and 8. In the illustration, the chambers 7 and 8 are vertically long.

The terminal end 5 is not provided with an outer wall as shown in FIG. It is open to all. Also, outer chamber 7
As shown in FIG. 3 and FIG.
form diagonally.

The above rectangular fork pipes 2 and 3 are obtained by extrusion molding of aluminum or the like.

Elongated holes 15 and 16 are formed in the partition wall 6 and the inner wall 14 of the terminal end portion 5 in the front-rear direction, and a plate-shaped chain adjuster 20 can be freely slid into the chamber 8 inside the partition wall 6 from the rear end surface 13. and insert the end of the rear wheel axle shaft 30 from the long hole 16 of the inner wall 14,
The axle shaft 30 passes through the circular hole 21 in the center of the chain adjuster 20 and extends outward from the long hole 15 of the partition wall 6.
A threaded portion 31 formed at the end of the screw protrudes outward.

Here, the chain adjuster 20 is connected to the elongated hole 1.
Flat surfaces 22a, 23a of protrusions 22, 23 that are sufficiently longer than 5, 16 in the front-rear direction and protrude vertically
An adjuster rod 24 protrudes from the rear end of the adjuster 20, and a threaded portion 25 at the rear end of the rod 24 is inserted into the inner chamber 8. It protrudes rearward from the rear end surface 13 through a circular hole 19a of the end plate 19 fixed thereto, and double nuts 26 and 27 are fastened to the threaded portion 25.

After adjusting the position of the rear wheel axle shaft 30 by the chain adjuster 20 in this way, the axle shaft 3
A flat washer 32 is interposed on the threaded portion 31 at the zero end, and an axle nut 33 is fastened.

If a rubber cap 40 is fitted between the outer wall 9 facing the outer chamber 7 and the partition wall 6, this portion can be closed and sealed.

As described above, since the seat surface of the axle nut 33 is brought closer to the partition wall 6 on the inside than the outside wall 9 of the rectangular fork pipe 2, the rear wheel axle shaft 30 can be shortened, and the chain adjuster 20 can be shortened.
Since the adjuster 20 only needs to be stored in the right chamber 8, the width (thickness) of the adjuster 20 can be reduced (to less than half that of the conventional one) and the weight can be reduced. In addition, since there is no need for an end piece that is processed separately as in the past, the cost is reduced, and the manufacturing process is easy because difficult crushing processing is not required.

As is clear from the above description, according to the present invention, the rear end of the rectangular fork pipe can be made more compact, the rear wheel axle shaft can be shortened, and the weight of the chain adjuster can be reduced at the same time, resulting in lower costs. It has advantages such as being cheap and easy to manufacture.

[Brief explanation of the drawing]

Figure 1 is a perspective view of the rear fork, Figure 2 is a plan view showing the axle shaft support structure at the end of the rectangular fork pipe, Figure 3 is the same side view without the nut shown, and Figures 4 and 5 are FIG. 2 is a cross-sectional view taken along line 2 and 2; In the drawing, 1 is a rear fork, 2 and 3 are square fork pipes, 5 is the terminal end thereof, 6 is a partition wall, 7,
8 is a chamber, 10 is a window, 14 is an inner wall, 15, 16 are long holes, 20 is a chain adjuster, 24 is a rod, 26, 27 are double nuts, 30 is a rear wheel axle shaft, 33 is an axle nut, 40 is It's a rubber cap.

Claims (1)

[Claims] 1. In the rear fork of a motorcycle that supports the rear wheel axle shaft at the end of the square fork pipe, a square fork pipe is extruded and the inside of the end is divided into left and right chambers by a partition wall, and this end is connected to the outside wall. The outer chamber is opened to the outside, and the chain adjuster is slidably housed in the inner chamber formed by the partition wall and the inner wall. A rear fork for a motorcycle, characterized in that the axle nut is fastened from the outer chamber to the end of the rear wheel axle shaft via a partition wall, a chain adjuster, and an inner wall. .