Back fork structure of two-wheel motorcycle

Abstract

A rear fork structure of motorcycle, to make axle supporting members as small as practicable and to firmly couple a rear fork with each axle supporting member, in a constitution where a lower coupling part to couple the bottom part of a rear cushion unit is integrally formed with the axle supporting member of a rear fork. The rear fork 34 of the motorcycle 10 is equipped with axle supporting members 84 at the tails of a left 81 a right arm 81 extending fore and aft. Each axle supporting member has a supporting hole 85 to support an axle 121 for a rear wheel, and the lower coupling part 86 to couple a bottom part 102 of the rear cushion unit 36 is extended upward from the front upper part more than the supporting hole, and the front end part 87 of the axle supporting member is located in the neighborhood of and ahead of the lower coupling part, and a joining surface 89 inclining down backward is formed in the front end part. Also at the tail of the left and right arms, a joining surface 97 inclining down backward is formed. The left and right arms and the left and right axle supporting members can be integrally constructed by overlapping joining the joining surfaces.

Description

technical field [0001] The invention relates to a rear fork structure improvement technology of a two-wheeled motorcycle. Background technique [0002] In a motorcycle, there is known a rear wheel suspension device in which a rear wheel is mounted on a rear fork pivotally supported on a vehicle frame (for example, refer to Patent Document 1 and Patent Document 2). [0003] [Patent Document 1] [0004] Japanese Patent Application Publication No. 5-193545 (page 2, Figure 1) [0005] [Patent Document 2] [0006] JP-A-2001-1977 (page 3-4, Figure 1-Figure 2) [0007] According to Patent Document 1, in the conventional rear fork structure, a frame cross member is erected between the front portions of the left and right arms extending forward and backward, and a lower connection portion connecting the lower end of the rear buffer unit is provided on the frame cross member. Furthermore, Axle fittings are respectively welded to the rear ends of the left and right arms, and the re...

AI Technical Summary

Problems solved by technology

However, since the lower connecting portion is simply formed integrally, the size of the axle assembly is increased.

Therefore, in the case of using a large axle component as a forging or casting, the mold for forming becomes larger and the manufacturing cost increases.

[0011] Also, when the lower connecting portion is integrally formed on the axle fitting, it must be strong enough to withstand the load from the rear buffer unit and the axle, and it is necessary to increase the bonding strength of the rear fork and the axle fitting, and the rear fork and the axle fitting must be enlarged

Images