JPS588635Y2 - Motorcycle rear arm - Google Patents

Description

[Detailed description of the invention] This invention relates to the rear arm of a motorcycle, and in particular, the rear axle on the side where the rear wheel drive chain is attached is equipped with a highly rigid chain guard using an end plate. Regarding the rear arm of a motorcycle.

In motorcycles, especially off-road motorcycles such as motocrossers, the chains for driving the rear wheels occasionally come off, and once they come off, the chain becomes impossible to drive, so it is necessary to prevent this as much as possible.

Even on regular motorcycles, if the chain comes loose, it can easily lead to an unexpected accident, so you need to be very careful.

For this reason, a chain guard is used that extends from the rear arm or the like to guide the chain near the sprocket of the rear wheel.

However, since conventional chain guards were made of sheet metal and attached to the rear arm, there was a problem that the chain guard itself could deform, and once deformed, it could actually cause the chain to come off. Ta.

The purpose of this invention is to solve this problem.The rear wheel of the rear arm is attached using a special end plate, and by providing a chain guard integrally with this end plate, the rigidity of the chain guard is greatly increased. The aim is to improve this and thereby effectively prevent the chain from coming off.

That is, according to the present invention, in the rear arm of a motorcycle, the end plate for mounting the rear axle on the side where the rear wheel drive chain is stretched is extended downward, and the opposite end plate is disposed opposite to the extended part. There is provided a rear arm for a motorcycle characterized in that a chain guard is integrally defined with the end plate by providing a plate and a bottom member forming the bottom of a space between the plates.

In this case, it is preferable that the facing plate is fastened to the extension of the end plate at a predetermined distance using a spacer.

Further, it is preferable that a U-shaped synthetic resin molded surface that opens upward is used as the bottom member, and that this is attached to the end plate extension and the opposing plate.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a side view of an off-road type motorcycle equipped with a rear arm according to the present invention.

The motorcycle includes a body frame 12 made by welding and assembling pipes, a front fork 14 and a front wheel 16 that are steerably attached to the front of the body frame, an engine 18 supported at the center of the body frame, and the body. A fuel tank 20 and a seat 22 are attached to the upper part of the frame, and a rear arm 2 is pivotably supported at the rear of the body frame.
4. It consists of a rear wheel 26 etc. attached to the rear part of the rear arm.

End plates 30 made of metal plates are welded to the rear portions of the left and right arm bodies 28 (only the left side is shown) of the rear arm 24, and the rear wheels 26 are mounted on a rear axle fastened between these left and right end plates. Supported.

A chain 36 is wound between the engine sprocket 32 on the output shaft of the engine 18 and the driven sprocket 34 on the rear wheel 26, and the rear wheel 26 is driven by the chain.

In the illustrated example, the chain 36 is provided on the left side of the vehicle body, and stretched at a position close to the left arm body 28.

Therefore, the rear arm 24 of the present invention has a chain 36.
A chain guard 38 is provided in the lower running path of the chain proximate the driven sprocket 34 and is configured to bypass the chain.

2 and 3 are views showing details of the chain guard 38, which is provided integrally with the end plate 30 of the rear arm 24.

That is, the end plate 30 on the side on which the rear wheel drive chain 36 is stretched is provided with an extension part 30A that extends downward to a position close to the driven sprocket 34 on the lower running path of the chain. It is defined by a facing plate 40 disposed opposite (on the inside in the illustrated example) and a bottom member 42 forming the bottom of the space between the extension and the facing plate.

The opposing plate 40 is fixed to the end plate 30 at two locations with bolts 46 and nuts 48, with a predetermined distance maintained by spacers 44.

The bottom member 42 has a width that is approximately equal to the distance between the extension part 30A and the opposing plate 40, and is made as a U-shaped component that opens upward.
0 with screws 46.

The bottom member 42 is made of, for example, a synthetic resin molded product, and the inner surfaces of its side walls and the bottom form a guide path that bypasses the chain 36, as shown in FIG.

Since the rear arm of the present invention has the configuration described above,
The chain guard 38 can be constructed integrally with the end plate 30 of the rear arm made of a thick plate, and its rigidity can be greatly improved.

Therefore, deformation of the chain guard can be prevented and the chain can be reliably prevented from slipping.

Furthermore, since the chain guard 38 is constructed using the end plate 30, its structure can be simplified.

[Brief explanation of the drawing]

Figure 1 is a side view of a motorcycle equipped with the rear arm of the present invention, Figure 2 is a partial side view showing the main parts of the rear arm of the present invention, and Figure 3 is a view taken along the line ■-■ in Figure 2. FIG. In each figure, the same reference numbers indicate the same parts.
12...Vehicle frame, 24...Rear arm, 28...Arm body, 30...
・End plate, 30A...End plate extension, 36...Chain, 38...
・Chain cart, 40... Opposing board, 42...
... Bottom member, 44 ... Spacer 46 ...
...Bolt, 48...Nut are shown respectively.

Claims (3)

[Scope of utility model registration request] (1) In the rear arm of a motorcycle, the end plate for mounting the rear axle on the side on which the rear wheel drive chain is stretched is extended downward, and the opposing plate placed opposite to the extended part and the space in between. A rear arm for a motorcycle, characterized in that a chain guard is defined integrally with the end plate by forming a bottom of the end plate and providing a bottom member. (2) In the rear arm for a motorcycle as described in item (1) above, the opposing plate is fastened to the end plate at a predetermined interval by a spacer. (3) In the rear arm of the motorcycle according to item (1) or item (2), the bottom member is an upwardly open U-shaped synthetic resin molded product, and both side walls thereof are connected to an extension of the end plate and the bottom member. A rear arm for a motorcycle, characterized in that it is attached to an opposing plate.