JPH0116715Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a rear wheel suspension system for a motorcycle that allows the lever ratio to be changed arbitrarily to increase it, thereby expanding the selection range of cushion characteristics and improving handling stability. It is related to.

2. Description of the Related Art In a motorcycle, a rear suspension unit is disposed between a swing arm that supports the rear wheel so as to be able to move up and down, and the vehicle body, so as to absorb vibrations from the rear wheel during driving. In general motorcycles, this rear traction unit is installed on each side of the rear wheel, but motorcycles used for competitions and those that can ride on rough roads have a rear traction unit installed in front of the rear wheel. Some devices are designed to reduce weight and increase the bank angle by providing only one.

The object of the present invention is to enable a large lever ratio (suspension rate) in this type of motorcycle, thereby expanding the selection range of cushion characteristics, and at the same time improving handling stability. Therefore, in the present invention, the center portion of the first bell crank is rotatably attached to the lower part of the seat frame connecting portion of the vehicle body frame, and the second bell crank is rotatably attached to the lower portion of the seat frame connecting portion of the vehicle body frame. The front end of the first bell crank is rotatably pivoted, and a rear traction unit is interposed between the front end of the first bell crank and the vicinity of the front end of a swing arm whose rear end supports the rear wheel. between the rear end of the first bell crank and the center of the second bell crank.
The rear end of the second bellcrank and the intermediate portion of the swing arm are connected by the second push rod.

Hereinafter, one embodiment of the present invention will be described with reference to FIG. 1. Reference numeral 1 is a vehicle body frame, the lower part (not shown) extends forward (to the left in the figure) to support the engine, and the upper part is attached to a seat frame (not shown). It is something that connects. A bracket 2 is integrally attached to a suitable location on the vehicle body frame 1, and the front end of a swing arm 3 is pivotally connected to the bracket 2 via a shaft 4. A rear wheel 5 is supported at the rear end of the swing arm 3 by an axle (not shown).

A substantially central portion of a first bell crank 6 is rotatably mounted on an upper portion of the vehicle body frame 1 via a shaft 7. The front end of this first bell crank 6,
A rear action unit 9 is attached by shafts 10 and 11 between the swing arm 3 and a bracket 8 provided near the front end thereof. A bracket 12 is attached to a portion of the body frame 1 slightly above the point where the bracket 2 is attached, and the front end of a second bell crank 13 is pivotally connected to this bracket 12 by a shaft 14. There is.

A first push rod 15 is pivotally mounted between approximately the center of the second bell crank 13 and the rear end of the first bell crank 6, and A second push rod 19 is connected to the shaft 20, between the rear end of the swing arm 13 and a bracket 18 provided at the intermediate portion of the swing arm 3.
21.

In this rear wheel suspension system configured in this manner, when the motorcycle runs, the rear wheel 5
When the swing arm 3 moves up and down, the swing arm 3 swings about the shaft 4. This swing stroke is
It is compressed when transmitted to the second bell crank 13 by the second push rod 19, so that the rear compression unit 9 is compressed and expanded, compared to the conventional one which is transmitted directly to the first bell crank 6. This means that the amount of water used will be small. This allows the lever ratio to be increased as shown in FIG.

When a damping effect is carried out in this way, the heavy reaction unit 9 is initially connected to two bell cranks 6, 13,
Since the push rods 15, 19, etc. are located as close as possible to the center of the vehicle body at the rear of the engine, that is, the center of gravity of the vehicle body, good steering stability is maintained even if each component moves due to operation. be able to.

Since the present invention is constructed as described above, the lever ratio can be arbitrarily changed and increased, thereby expanding the selection range of cushion characteristics and obtaining a motorcycle with cushion characteristics suitable for the intended use. will be possible.

Since the structure for this purpose is obtained by locating the heavy rear action unit and its related parts as close to the center of gravity of the vehicle body as possible, good steering stability can be obtained during operation.

[Brief explanation of the drawing]

FIG. 1 is a front view of essential parts of an embodiment of the present invention, and FIG. 2 is a graph showing the operating characteristics of the device shown in FIG. 1...Vehicle frame, 3...Swing arm,
5... Rear wheel, 6... First bell crank, 9...
Reaction unit, 13...Second bell crank, 15...First push rod, 19...
…Second Pushyurotsudo.

Claims (1)

[Scope of utility model registration request] A center portion of a first bell crank is rotatably attached to the lower part of the seat frame connecting portion of the vehicle body frame, and a front end portion of a second bell crank is attached to a portion of the vehicle body frame located below the pivot portion. A rear action unit is interposed between the front end of the first bell crank and the vicinity of the front end of a swing arm that supports the rear wheel at the rear end. The rear end of the crank and the middle part of the second bell crank are connected by a first push rod, and the rear end of the second bell crank and the middle part of the swing arm are connected by a second push rod. A rear wheel suspension system for a motorcycle, characterized by: