JPS603031Y2 - Motorcycle rear wheel suspension system - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a rear wheel suspension system for a motorcycle.

A conventional rear wheel suspension system for a motorcycle has a configuration as shown in FIG. 1, for example.

In the figure, 1 is a frame (referring to the vehicle body frame), 2 is a support shaft that rotatably supports the front end of the swing arm 3, which rotatably supports the rear wheel 4 at the rear end with respect to the frame 1, and 5 7 is a support shaft that rotatably supports the lower end of the rod 6 on the swing arm 3; 7 is a support shaft that rotatably supports the bell crank 8 on the frame 1; the rear end of the bell crank 8 is the upper end of the rod 6; The front end of the bell crank 8 is rotatably connected to the upper end of the shock absorber 10 by a support shaft 11, and the lower end of the shock absorber 10 is connected to the swing arm 3 by a support shaft 12.
It is rotatably supported.

With this configuration, the load applied to the rear wheel 4 is transmitted to the shock absorber 10 via the swing arm 3, rod 6, and bell crank 8, thereby absorbing the shock.

However, in such conventional suspension systems, it is not possible to freely set or change the operating conditions of the shock absorber in response to the driver's weight, road conditions, etc.
Particularly in motorcycles for motocross, there is a drawback that not only the so-called riding comfort but also the stability during running are deteriorated.

The present invention was devised in view of the above situation, and it is an object of the present invention to provide a suspension system in which the operating conditions of the shock absorber can be freely changed in accordance with the conditions of the driver, the driving route, etc.

An embodiment of the present invention will be described below with reference to FIGS. 2 to 6 (the same reference numerals are given to the parts corresponding to those in FIG. 1).

2 and 3 show a plan view and a side view of the bell crank 6 used in the suspension system according to the present invention.

The bell crank 8 includes a mutually independent first arm portion 8a, a pair of left and right second arm portions 8b, and a spacer 8C.

The front end of the first arm 8a is rotatably coupled to the support shaft 11, that is, the upper end of the shock absorber 10, and the front end of the first arm 8a is
Each rear end of b is rotatably connected to the support shaft 9, that is, the upper end of the rod 6.

The rear end of the first arm 8a and the front end of the second arm 8b are rotatably coupled to the support shaft 7 using a nut 13, with a spacer 8c in between.

A gear 8d is formed on each of the mutually engaging surfaces of the first arm 8a and the second arm 8b, and by loosening the nut 13, the gears 8d are released from each other, and the support shaft 7 is centered. After setting the angle between the first arm part 8a and the second arm part 8b to a desired value, the gears 8d are engaged with each other again and the nut 13 is tightened. The angle between the second arm portion 8b and the second arm portion 8b can be set to a predetermined angle.

Of course, the minimum change angle of the angle formed by both arm portions 8a and 8b is an angle corresponding to one tooth of gear 8d.

When the first arm part 8a and the second arm part 8b are set at a predetermined angle α, β, or γ as shown in FIG. 4, the lever ratio or shock absorber 10 with respect to the stroke of the rear wheel 4 in each case is The change in the stroke (the upward movement of the rear wheel 4 around the support shaft 2) is as shown in Fig. 5.
Further, the change in the load with respect to the ground contact direction of the rear wheel 4 with respect to the stroke of the rear wheel 4 is as shown in FIG.

In FIG. 4, the solid line indicates the raised position of the rear wheel 4, and the dashed line indicates the lowered position.

Furthermore, in FIG. 6, the dashed line is an ideal line depicting the desired rear wheel load.

Therefore, depending on the driver, road conditions, etc., the first and second
By setting the angle between the arm portions 8a and 8b to a predetermined value, the operating conditions of the shock absorber 12 can be set to desired characteristics.

Note that, unlike the embodiment, the mounting positions of the rod 6 and the shock absorber 10 may be reversed.

Further, in the embodiment, both arm portions 8a of the bell crank 8.

8b are both connected to the swing arm 3 in the end, but one may be connected to the frame 1.

As described above, the present invention allows the characteristics of the shock absorber to be selected depending on the driver and the driving road conditions, thereby improving ride comfort and driving stability. It is suitable for use in motocross motorcycles that are significantly different.

[Brief explanation of drawings]

Fig. 1 is a side view showing the structure of a conventional rear wheel suspension system for a motorcycle, Fig. 2 is a plan view showing the structure of the bell crank according to the present invention, and Fig. 3 is a side view showing the structure of the bell crank according to the present invention. FIG. 4 is an explanatory diagram showing the operation of the bell crank according to the present invention, and FIGS. 5 and 6 are characteristic diagrams of the rear wheel suspension system according to the present invention. 3... Swing arm, 4... Rear wheel,
8...Bell crank, 8a...First arm, 8b...Second arm, 10...
shock absorber.

Claims (1)

[Scope of utility model registration request] A bell crank is provided above the swing arm pivot point of the vehicle body frame, the middle portion of which is pivotally connected and rotates.
A rear wheel suspension system for a motorcycle in which one end of the bell crank and the swing arm are rotatably connected by a rod, and the other end of the bell crank and the swing arm or the vehicle body frame are connected by a shock absorber. A rear wheel suspension for a motorcycle, characterized in that the crank is divided into a first arm portion and a second arm portion at the pivot portion, and the two arm portions are configured to engage with each other at different angles. Device.