JPH0440236B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rear wheel shock absorbing device for a motorcycle that is compact and lightweight.

[Conventional technology]

Rear wheel shock absorbers installed in off-road motorcycles that drive on rough terrain have a rear arm that supports the rear wheel that swings up and down more than regular motorcycles, and that also has a shock absorber that absorbs changes in the rear arm's swing. A so-called plug-resive type device is used in which the buffering force increase rate of the device is increased.

Japanese Utility Model Application Publication No. 55-117382 is an example of such a progressive type shock absorber, in which the middle part of a rotating member is pivoted to the rear arm, and the front end thereof is connected to the vehicle body frame via a link. At the same time, the lower end of the shock absorber is connected to the rear end side. However, as mentioned above, this progressive type shock absorber requires extra parts such as rotating members and links compared to a normal shock absorber, which causes the problem that the device becomes larger and heavier. For this reason, some cars have only one shock absorber installed at the center in the width direction of the vehicle as part of the simplification process, but in this case, the rear wheel must be placed at the rear so that it does not interfere with the shock absorber. The rear arm became longer, and it was not an essential solution to making it more compact and lighter.

[Problem to be solved by the invention]

An object of the present invention is to provide a rear wheel shock absorber for a motorcycle that can be made even more compact and lightweight in the progressive type shock absorber described above.

[Means to solve the problem]

The present invention achieves the above object by rotatably supporting a pair of left and right lower arms for supporting rear wheels at the lower rear of a vehicle body frame in which an engine is mounted, via a bracket, and connecting the rear arms between the pair of rear arms. A rotating member is connected to the front of the wheel by a horizontal reinforcing member, and a rotating member is rotatably supported on the rear arm at an intermediate portion thereof, and a rotating member is attached to one of the front and rear ends of the rotating member, and is attached to a central area in the width direction of the vehicle body frame. In a rear wheel shock absorber for a motorcycle, in which a lower end of only one shock absorber is connected, and an end of a link pivoted to the body frame is connected to the other end, the pivot point of the rotating member is reinforced with the lateral reinforcement. The rotating member is provided on or near the axis of the member, and the rear end side of the rotary member is formed into a bifurcated shape so as to sandwich the rear wheel, the lower end of the link is connected to the rear end side, and the lower end of the link is connected to the rear end side, and the The lower end of the shock absorber is connected at the rear near the pivot point of the front end of the rear arm.

If only one shock absorber is placed in the center area of the vehicle body frame in the width direction, connect the shock absorber to the front end of the pivoting member pivoted in the middle at the rear near the pivot point of the rear arm, and Since the link is connected to the engine, the shock absorber can be compactly placed close to the rear of the engine. In addition, in the device of Japanese Utility Model Application Publication No. 55-117382, in which the connection relationship between the shock absorber and the link with respect to both ends of the rotating member is reversed, a link is placed on the rear arm to avoid interference between the shock absorber and the rear wheel. Although a triangular frame structure must be provided, in order to eliminate the need for such a triangular frame structure, the vehicle is not only more compact and lightweight, but also has a lower center of gravity, improving running performance and maneuverability. Moreover, since the rear end of the rotating member is bifurcated to sandwich the rear wheel, the rear wheel can be placed as far forward as possible, and the front-to-back length of the rear arm is shortened, making it even more compact. and enables weight reduction.

In addition, in the above configuration, when increasing the stroke of the shock absorber, while increasing the distance between the intermediate pivot point and the front end of the rotating member, it is also possible to increase the distance between the intermediate pivot point and the rear end. However, by such a measure, the link connected to the rear end of the rotating member is moved further toward the front, so that it is advantageous to make it even more compact.

Furthermore, since the shock absorber can be placed close to the rear of the engine as described above, the moment of inertia around the center of gravity of the motorcycle is reduced, improving running performance and handling performance.

〔Example〕

In the illustrated embodiment, an engine E is mounted on a vehicle body frame 1, and a pair of left and right rear arms 2, 2 are rotatably attached to the lower rear of the vehicle body frame 1 via a bracket 1a, and a Rear wheel 3 is supported. A lateral reinforcing member 2a is connected and fixed between the pair of left and right rear arms 2, 2 at a position in front of the rear wheel 3.
A rotating member 4 is rotatably supported at a.

The rotating member 4 has an intermediate portion pivoted to the horizontal reinforcing member 2a, and a lower end 6a of the shock absorber 6 pivoted to the widthwise center area of the vehicle body frame 1 is attached to the front end side of the rotating member 4.
The shock absorber 6 is rotatably connected near the rear of the pivot portion of the rear arm 2, and the upper end of the shock absorber 6 is pivotally supported on the vehicle body frame 1. By such a connection, the buffer 6
can be placed close to the rear of engine E,
This reduces the moment of inertia around the center of gravity of the motorcycle, improving running and handling performance.

Further, the lower end 5a of a link 5 is rotatably connected to the rear end side of the rotating member 4, and the upper end side of the link 5 is connected to the vehicle body frame 1. Further, the rear end side of this rotating member 4 is formed into a bifurcated shape as shown in FIG. 2, and the front part of the rear wheel 3 is disposed between the two forks. . With this configuration, the rear wheel 3 is disposed as far forward as possible, and the longitudinal length of the rear arm 2 is shortened, making it possible to make the vehicle compact and lightweight. Such a bifurcated shape may be a shape as shown in FIGS. 3A and 3B, and the intermediate portion is not supported directly on the horizontal reinforcing member 2a, but supported on a bearing 7 on the rear arm adjacent thereto. You can do it like this.

As shown in FIG. 4, in the rear wheel shock absorbing device configured as described above, when the rear arm 2 changes from the position shown by the solid line to the position shown by the chain line, the rotating member 4 rotates clockwise via the link 5. , it is possible to contract the shock absorber 6 at a rate greater than the rate of displacement of the rear arm 2, thereby increasing the rate of increase in the buffer force.

According to the connection structure of the rotating member 4, the shorter the distance between the intermediate pivot point 2a and the connection point 5a to the link 5 on the rear end side, the more the intermediate pivot point starts from the connection point 5a. By increasing the lever ratio of the distance to the connection point 6a of the shock absorber 6 to the distance to the shock absorber 6, the stroke of the shock absorber 6 can be increased, and the shock absorbing force performance can be increased. Further, by this procedure, the connection point on the rear end side of the rotating member 4 is moved to the front side, so that the rear arm 2 can be further shortened, contributing to compactness and weight reduction.

〔Effect of the invention〕

As described above, according to the present invention, in a progressive type shock absorber, when only one shock absorber is disposed in the center area in the width direction of the vehicle body frame, the pivot of the rear arm is placed on the front end side of the rotating member pivoted at the intermediate portion. Since the shock absorber is connected to the rear near the fulcrum, and the link is connected to the rear end side, the shock absorber can be disposed close to the rear of the engine in a compact manner. Moreover, since the rear end of the rotating member is bifurcated so as to sandwich the rear wheel, the rear wheel can be placed as far forward as possible, and the front-to-back length of the rear arm can be shortened. This makes it possible to make the product more compact and lightweight.

Furthermore, since the shock absorber is arranged compactly and close to the rear of the engine as described above, the moment of inertia around the center of gravity of the motorcycle can be reduced, and running performance and maneuverability can be improved.

[Brief explanation of drawings]

FIG. 1 is a schematic side view of a motorcycle equipped with a shock absorber according to an embodiment of the present invention, FIG. 2 is a plan view of the same shock absorber, and FIGS. 3 A and B are plan views of a shock absorber according to another embodiment. and a side view, and FIG. 4 is an explanatory diagram of the operation of the shock absorber shown in FIG. 1. 1...Vehicle frame, 2...Rear arm, 2a
... Lateral reinforcement member, 3 ... Rear wheel, 4 ... Rotating member,
5...Link, 6...Buffer.

Claims (1)

[Scope of Claims] 1. A pair of left and right rear arms for supporting the rear wheels are rotatably supported via brackets at the lower rear of the vehicle body frame in which the engine is mounted, and the rear arms are connected between the pair of rear arms to support the rear wheels. connected at the front by a horizontal reinforcing member, a rotating member is rotatably supported on the rear arm at an intermediate portion thereof, and one of the front and rear ends of the rotating member,
In the rear wheel shock absorber for a motorcycle, the lower end of only one shock absorber is connected to the center region in the width direction of the body frame, and the end of a link pivoted to the body frame is connected to the other end, The pivot point of the moving member is provided on or near the axis of the horizontal reinforcing member, the rear end side of the rotating member is formed into a bifurcated shape so as to sandwich the rear wheel, and the link is provided on the rear end side. A rear wheel shock absorber for a motorcycle, wherein the lower ends of the shock absorber are connected to each other, and the lower end of the shock absorber is connected to the front end side of the shock absorber at the rear near the pivot point of the front end of the rear arm.