JPH0142875B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rear wheel suspension system for a motorcycle, and a structure in which a cushion unit is mounted approximately in the center of the vehicle body, without the conventional bell crank. and then
It is designed to provide space in the center of the vehicle body to store various parts.

The rear wheel of a motorcycle is pivoted to the rear end of a swing arm whose front end is pivotally connected to the vehicle body frame, and a cushion unit interposed between the swing arm and the upper portion of the vehicle body frame absorbs shock. It is supported in this way. In this case, for motorcycles that require a large swing stroke in the vertical direction of the rear wheel, a structure is adopted in which the cushion unit is placed approximately in the center of the vehicle body and its lower end is pivoted near the front end of the swing arm. is taken.

In this type of motorcycle, the upper end of the cushion unit is pivotally connected to one end of a lever called a bell crank whose middle part is pivotally connected to the body frame, and the other end of the bell crank is connected via a rod. Usually, the structure is connected to the swing arm. Using the bellcrank in this way,
Since bending stress is constantly applied to this bell crank, it is necessary to use a bell crank with high strength, and it is also large in size. There was a problem with space limitations in accommodating cleaners and batteries.

The present invention was made to solve this problem, and instead of using the conventionally used bell crank, it is installed at the bottom of the body frame of the rotating plate and rod to achieve the desired purpose. This is what I did.

Hereinafter, one embodiment of the present invention will be explained with reference to the drawings. Reference numeral 1 is a vehicle body frame formed by combining pipe materials, and although not shown in the drawings, an engine is located in the center (left part of the drawing). A fuel tank is attached to the top of the tank, and a seat is attached behind it.
2 is a rear fender attached to the upper rear end of the vehicle body frame 1.

A bracket 3 made of a plate is attached to the lower part of the vehicle body frame 1.
The front end of the swing arm 4 is pivotally connected to the shaft 5. At the rear end of the swing arm 4 is an axle 6
is inserted, and the rear wheel 7 is rotatably supported. One end of a rotating plate 8 is pivotally connected to a portion of the swing arm 4 above the pivot point to the bracket 3 by a shaft 9.

The other end of the rotating plate 8 is connected to one end of a rod 11 by a shaft 10, and the other end of the rod 11 is pivotally connected to a bracket 13 provided at the intermediate portion of the swing arm 4 by a shaft 12. . The connection point between the rotating plate 8 and the rod 11 and the vehicle body frame 1
Between the upper part of the cushion unit 14
is interposed. In this case, the rotating plate 8
The mounting position of the cushion unit 14 is set so that the swing arm 4 assumes a substantially right-angled posture when the upward stroke of the swing arm 4 is at its maximum (maximum compression).

This rear wheel suspension system configured in this manner has a large stroke when the swing arm 4 rises (rotates around the shaft 5) due to the force that the rear wheel 7 receives from the road surface while driving. As the amount of compression increases, the amount by which the cushion unit 14 is compressed increases, and the damping force also increases accordingly. That is, the lifting force of the swing arm 4 is transmitted to the lower end of the cushion unit 14 via the rotating plate 8 and the rod 11, and compresses it (see the broken line in the figure). In this case, only a tensile force is applied to the rotating plate 8 and the rod 11, and no bending stress is applied. Therefore, their rigidity does not need to be increased as in conventional bell cranks.

Since the present invention is configured as described above, it has the following effects.

Since the rotating plate and rod are attached to the bottom of the car body, space can be secured in the center of the car body to store the air cleaner and battery.

It is constructed from a conventional bell crank, a rotary plate, and a rod, and no bending stress is applied to these, making it easy to manufacture.

By appropriately selecting the mounting position and dimensions of the rotating plate and the rod, it is possible to obtain a desired damping force characteristic, for example, a characteristic in which the damping force increases as the stroke increases.

[Brief explanation of drawings]

The figure is a front view schematically showing the main parts of an embodiment of the present invention. 1...Vehicle frame, 3, 13...Bracket, 4...Swing arm, 5, 9, 10, 12
... shaft, 6 ... axle, 7 ... rear wheel, 8 ... rotation plate, 11 ... rod, 14 ... cushion unit.

Claims (1)

[Claims] 1. One end of the rotating plate is pivotally connected to the vehicle body frame above the pivot point of the swing arm to the vehicle body frame,
The other end of the rotating plate is connected to one end of the rod, and the other end of the rod is pivotally connected to the middle part of the swing arm, and the connection point between the rotating plate and the rod is connected to the upper part of the vehicle body frame. A rear wheel suspension system for a motorcycle, characterized in that a cushion unit is interposed between the two wheels. 2. The rear wheel suspension system for a motorcycle according to claim 1, wherein the rotating plate and the cushion unit are mounted at substantially right angle positions at the maximum upward stroke of the swing arm.