JPH065998Y2 - Autobuy swingarm - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a swing arm of a motorcycle.

[Prior art and its problems] Motorcycles are designed so that the front end of a gate-shaped swing arm can be pivotally attached to a frame to provide a swing cushion. Axle is attached.

Recently, light alloy drawn pipes have been used to reduce the weight of swing arms. In this case, a pipe material having a rectangular cross section is used, and the cross section is enlarged and the wall thickness is increased in order to increase rigidity. In addition, the chain pull, which is inserted from the rear end of the swing arm and through which the axle is passed, sometimes becomes large. 59-194
See Japanese Patent Publication No. 94.

The swing arm of the motorcycle of the present invention solves the above problems, and its purpose is to provide a swing arm that is lightweight and has high rigidity even if it is thin, and that prevents the chain pulling inserted in the swing arm from becoming large. The purpose is to do.

[Means for Solving Problems] The present invention provides a motorcycle swing arm that solves the above problems, and is a hollow swing arm that rotatably supports a rear wheel. Partition walls that make the hollow into a three-layer space so that the cross section along the direction becomes an eye shape are provided in the hollow along the longitudinal direction of the swing arm and in parallel in the up-and-down direction. Is a component that gives tension to the chain for transmitting power to the rear wheel, and has a through hole that penetrates the rear wheel in the axial direction and contacts the partition wall and the inner wall surface of the arm portion. Of the side wall of the swing arm including the inner wall surface corresponding to the portion where the chain pull is located, a lateral hole extending in the longitudinal direction of the swing arm is formed. The axle of the rear wheel is inserted into the through hole and the chain pull is fastened to the swing arm via the axle.

[Operation] Therefore, according to the present invention, since the partition walls are provided in the hollow of the swing arm along the longitudinal direction thereof and in parallel with the vertical direction, the partition walls increase the strength of the swing arm. Further, since the chain pull is inserted while being in contact with the partition wall and the inner wall surface of the arm portion, the rigidity of the chain pull is added to the strength of the partition wall to further enhance the strength.

Moreover, since sufficient strength can be ensured, the cross section of the swing arm does not become large.

[Embodiment] The present invention will be described below with reference to an embodiment shown in the drawings.

The front end of the swing arm 1 is pivotally attached to the frame 2 via a support shaft 3 so as to swing and cushion by a cushion unit (not shown). Further, the swing arm 1 includes the left and right arm portions 1 extending rearward thereof.
1 and 1r (only 1l on the left side is shown in the drawing) is formed in a gate shape, and a rear wheel 4 of a motorcycle is rotatably supported at its rear end via an axle 5.
The axle 5 is laterally passed through the left and right arm portions 11 and 1r and fastened to the arm portions 11 and 1r.

The rear wheel 4 is connected to the engine 6 in front of the swing arm 1 by a chain (not shown).
The power of the engine 6 is transmitted to the rear wheels 4 to drive the rear wheels 4.

Further, the arm portions 11 and 1r have a hollow shape, and the hollow portion 1a has a three-dimensional space region so that the arm portions 1l and 1r have a cross section along the forehead direction. The upper partition wall 1u and the lower partition wall 1d are provided along the longitudinal direction of the swing arm 1 and in parallel with each other in the vertical direction. Such a swing arm 1 is made of a drawn pipe material.

Further, in the extraction hole 10 between the partition wall 1u and the partition wall 1d, a through hole 9 which is a component for tensioning the chain for transmitting power to the rear wheel 4 and penetrating in the axle direction of the rear wheel 4 is provided. The chain puller 8 is inserted while being in contact with the partition walls 1u and 1d and the left inner wall surface 1′l and the right inner wall surface 1′r of the arm portions 1l and 1r, respectively.

Then, each inner wall surface 1'1, 1'in the extraction hole 10
Lateral holes 7 and 7 extending in the longitudinal direction of the swing arm 1 are formed substantially in the center in the vertical direction at a portion of the side wall of the swing arm 1 including the r where the chain puller 8 is located.

The axle 5 is inserted into the lateral holes 7, 7 and the through hole 9, and the chain puller 8 is fastened to the swing arm 1 via the axle 5.

A threaded rod 11 is provided on the rear side of the chain puller 8. The threaded rod 11 is for eliminating slack in the chain by, for example, a rider pulling the axle 5 rearward of the vehicle when the chain extends.

The washer 12 is attached to the swing arm 1 via the axle 5, has a scale, and can align the left and right chain pullers 8 with each other.

Note that the reference numerals 13 and 14 denote a spacer and a closing plate, respectively.

Therefore, according to the swing arm 1, the hollow 1a
Since the upper partition wall 1u and the lower partition wall 1d are provided inside the swing arm 1 in parallel with the longitudinal direction of the swing arm 1, the strength of the swing arm 1 is increased by these partition walls 1u and 1d.

Furthermore, upper and lower partition walls 1u and 1d and arm portions 11 and 1r.
Since the chain puller 8 is inserted in contact with the respective left and right inner wall surfaces 1′l, 1′r of the chain, the strength of the chain puller 8 is increased by the strength of the left and right inner wall surfaces 1′l, 1′r. Is added, the strength is further increased.

As described above, the rigidity of the swing arm 1 can be sufficiently increased even if the thickness of the swing arm 1 is reduced to reduce the weight.

Further, since sufficient strength can be secured without making the cross section of the swing arm 1 large, the swing arm 1
It is possible to prevent the chain pulling 8 that goes inside from becoming large.

[Advantage of the Invention] According to the swing arm of the motorcycle of the present invention, since the partition wall is provided in the hollow along the longitudinal direction and parallel to the vertical direction, the partition wall enhances the strength of the swing arm.

Furthermore, since the chain pull is inserted in contact with the partition wall and the inner wall surface of the swing arm, the rigidity of the chain pull is added to the strength of the partition wall, and the strength of the swing arm is further enhanced.

Therefore, the swing arm having sufficient rigidity can be provided even if the thickness of the swing arm is reduced to reduce the weight.

Further, since sufficient strength can be ensured and the cross section of the swing arm does not become large, it is possible to prevent the chain pulling into the swing arm from increasing in size.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an overall side view, FIG. 2 is an enlarged vertical sectional view of a portion taken along the arrow A in FIG. 1, and FIG. 1 ... Swing arm, 1a ... Hollow, 1l ... Left arm part, 1r ... Right arm part, 1'l ... Left inner wall surface, 1 '
r ... right inner wall surface, 1u ... upper partition wall, 1d ... lower partition wall, 2 ... frame, 4 ... rear wheel, 5 ... axle, 7 ...
Side hole, 8 ... Chain pulling, 9 ... Through hole, no code ...
… Sidewall.

Claims (1)

[Scope of utility model registration request] 1. In a hollow swing arm that rotatably supports a rear wheel, a partition wall that makes the hollow into a three-layer space so that the arm section has a cross section along the forehead direction. A part that is provided in the hollow along the longitudinal direction of the swing arm and in parallel with the up-down direction, and is a component that applies tension to a chain for transmitting power to the rear wheels between the partition walls. A chain pull having a through hole penetrating in the axle direction is inserted in a state of being in contact with the partition wall and the inner wall surface of the arm portion, and in a portion of the side wall of the swing arm including the inner wall surface where the chain pull is located. A lateral hole extending in the longitudinal direction of the swing arm is formed in a corresponding portion, and an axle of the rear wheel is inserted into the lateral hole and the through hole, and the chain pulling is performed through the axle through the axle. Motorcycle swing arm of which is fastened to.