JPS6365557B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rear wheel suspension system for motorcycles, motorized bicycles, etc.

The rear wheel suspension system in conventional two-wheeled vehicles is
As shown in the figure, two shock absorbers 3 and 3' are generally installed between the swing arm 1 and the vehicle body frame 2 near the seat. Usually the buffer 3,
3', a spring and a shock absorber are installed on a concentric shaft. However, as shown in the same figure, when the shock absorbers 3 and 3' are installed on the left and right sides of the vehicle, it is very difficult to make the functions of the shock absorbers 3 and 3' completely homogeneous in terms of production. There was a problem in which twisting occurred between the two and the steering stability was significantly impaired.

Therefore, recently, as shown in FIG. 2, as a suspension system for this type of two-wheeled vehicle, a rotating arm 4 is rotatably supported on an undertube of a vehicle body frame 2, and the tip of the rotating arm 4 is connected to the vehicle body. A shock absorber 3 is pivotally supported between the frame 2 and a tension rod 5 that connects the approximately central portion of the rotating arm 4 and the swing arm 1.
There is one that is connected with (see Utility Model Application Publication No. 57-46089). According to this suspension system, the shock absorber 3 is located in the center of the vehicle body, and since the single shock absorber functions, the torsion of the vehicle body as described above does not occur, and the handling stability is improved. It was done.

However, in this case, the rotating arm 4, tension rod 5, etc. are arranged at the bottom of the vehicle body, which makes the relationship between the vehicle body and the rear wheels very complicated, requiring time and effort during maintenance or cleaning, and also requiring various electrical components. It was difficult to secure storage space for such items.

The present invention was made in view of the above circumstances, and attempts to solve the above-mentioned problems by separating the spring and shock absorber of the shock absorber and incorporating the shock absorber into the shaft support of the swing arm. It is something.

An embodiment of a rear wheel suspension system according to the present invention will be described below with reference to the drawings. In FIG. 3, the same reference numerals as in FIG. 1 are the same, so detailed explanation will be omitted. A rear wheel 6 is pivotally supported at the rear end of the swing arm 1. 7 is a shock absorber,
It is fixed to the swing arm 1 as described later. 8 is a spring interposed between the swing arm 1 and the vehicle body frame 2.

Figure 4 is a cross-sectional plan view taken along line - in Figure 3;
FIG. 5 is a longitudinal sectional side view taken along the line -- in FIG. 4. In these figures, reference numeral 9 denotes a support shaft of the shock absorber 7. The support shaft 9 rotates together with the swing arm 1 through spline fitting, etc., and rotates together with the swing arm 1 on a bracket 11 welded to the cross pipe 10. It is pivoted for free movement. 13
is the main body of the shock absorber 7, which is fixed to a bracket 12 welded to a cross pipe 10. 14 is a sliding wall formed integrally with the support shaft 9;
Reference numeral 5 denotes a fixed wall integrally formed on the shock absorber main body 13, and the sliding wall 14 and the fixed wall 15 liquid-tightly divide the chamber into two chambers A and B.
B is filled with oil. On the other hand, fixed wall 15
A small hole 16 and a large hole 17 are cut out, and valves 18 and 19 are provided on the chamber B side of the small hole 16 and on the chamber A side of the large hole 17, respectively. A gusset 20 is welded between the left and right swing arms 1, and a bracket 2 is fixed on the gusset 20.
A spring 8 is pivotally supported at 1.

In the rear wheel suspension system of the present invention configured as described above, when the vehicle passes a convex portion, the rear wheel 6 rotates upwardly about the support shaft 9 of the shock absorber 7 together with the swing arm 1 in FIG. move. At this time, as can be seen in the detailed view of FIG. compresses the oil to high pressure. On the other hand, the oil in chamber B becomes a negative pressure, valve 18 is opened while valve 19 remains closed, and oil in chamber A gradually flows into chamber B through small hole 16. At the same time, a spring 8 interposed between the swing arm 1 and the vehicle body frame 2 cushions the shock when the vehicle passes through the convex portion.

After passing the convex portion, the rear wheel 6 attempts to rotate downward together with the swing arm 1. At this time,
Conversely, in the shock absorber 7, the oil in the chamber B is compressed to a high pressure. On the other hand, the oil in chamber A becomes negative pressure, valve 18 closes and valve 19 opens, and the oil in chamber B rapidly passes through large hole 17 and flows into chamber A.

Next, when passing through the recess, the process is completely opposite to the above.

Thus, the rear wheel suspension system of the present invention absorbs and alleviates vibrations and shocks of the vehicle when the vehicle is running.

As described above, according to the present invention, a shock absorber of a rear wheel suspension system in a motorcycle or the like is divided into a spring and a shock absorber, and the shock absorber is built into the shaft support of the swing arm.
The spring is interposed between the swing arm and the body frame, giving it a sleek appearance and making it easier to secure storage space for electrical components, etc.

Furthermore, since the left and right swing arms are connected by a shock absorber and a gusset, the rigidity of the swing arms themselves is increased, making it possible to improve the stability of the vehicle. At the same time, since the shock absorber and spring are located at the center of the vehicle body in the lateral direction, twisting does not occur between them and the rear wheels of the vehicle body, further improving maneuverability.

If the stopper 22 is integrally formed on the inner wall of the shock absorber main body 13 in FIG. 5, the amount of upward movement of the swing arm can be restricted, and the rear wheel can be attached to the seat lower frame (including the fender). It is possible to prevent the situation from bottoming out. Alternatively, the swing arm and the shock absorber may be fixed together to fix the support shaft. Further, the springs may be provided on the left and right sides of the vehicle body as in the conventional case.

[Brief explanation of drawings]

Figures 1 and 2 are left side views showing a conventional rear wheel suspension system, Figures 3 to 5 are views showing an embodiment of the rear wheel suspension system according to the present invention, and Figure 3 is a left side view. , FIG. 4 is a cross-sectional plan view taken along the line - in FIG. 3, and FIG. 5 is a longitudinal cross-sectional side view taken along the line - in FIG. 4. 1...Swing arm, 2...Vehicle frame,
6... Rear wheel, 7... Shock absorber, 8...
…spring.

Claims (1)

[Claims] 1. A motorcycle in which the front end of a swing arm that pivotally supports a rear wheel at the rear end is pivotally supported on a body frame, a shock absorber is built into the shaft support, and a spring is interposed between the swing arm and the body frame. Rear wheel suspension.