JPH0227700Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to a rear wheel suspension system for motorcycles, tricycles, etc.

(Prior Art) A swing arm type rear wheel suspension system in which a rear wheel is supported by a swing arm and a cushion unit is interposed between the swing arm and the vehicle body is used in motorcycles and the like.

As such a suspension system, a rear fork 52 forming a swing arm on a vehicle body 51 as shown in FIG.
The rear wheel 53 is rotatably supported at the rear end of the rear fork 52, and one end of the rear action unit 55 is pivotally connected to the seat rail 54 on the vehicle body 51 side. The middle point of the link 56 is pivotally connected to one end of the link 57, the other end of the link 57 is pivotally connected to the vehicle body side, and the rear fork 5 is pivotally connected to the other end of the link 56.
A suspension system in which the cushioning characteristic of the cushion unit 55 is made progressive (gradually increasing) by the operation of the links 56 and 57 with a swing amount of 2 is in practical use.

(Technical problem to be solved by the invention) In the above progressive suspension system, the spring constant near the riding area is lowered to improve ride comfort, while the spring constant is nonlinearly increased as the stroke approaches the full stroke. The purpose is to prevent bottoming.

By the way, when gradually changing the buffer characteristics,
If the spring constant is changed suddenly from a certain stroke, you will experience this change in the rising part and this is not desirable.On the other hand, if the spring constant is changed in a straight line, it will be easier to bottom out, or when the riding speed is around 1G. The ride comfort is no longer soft,
Undesirable. By the way, the spring in the rear action depends on the stroke, while the damping force of the damper depends on the piston speed, so the range in which both can be achieved is limited.

The present invention was made to solve the above technical problems, and its purpose is to gradually increase the spring characteristics suitable for the spring characteristics of the spring and the damping force characteristics of the damper, thereby improving riding comfort and repeatability. To provide a progressive type suspension device with further improved safety.

(Means for solving the technical problems) The means for solving the above technical problems is to support the rear wheel with a swing arm, and pivot one end of a rear suspension unit consisting of a spring and a damper to the vehicle body. In a rear wheel suspension system for motorcycles, tricycles, etc., in which the other end of the rear action unit is pivotally connected to the swing arm, the lower end of the spring is installed in an oil chamber formed between an inner cylinder and an outer cylinder that constitute a damper. A cylindrical lower seat supporting the inner cylinder is slidably fitted, and the oil chambers in the inner cylinder are communicated with each other, so that the damper and the spring can be operated independently.

(Function) According to the above means, the damper and spring that constitute the progressive link mechanism are supported separately, and the respective rates of change can be set to optimal characteristics.

(Embodiment) A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a rear side view of a motorcycle to which a rear wheel suspension system according to the present invention is applied, in which 1 is a frame of the motorcycle, a seat rail 2 is extended rearward from the rear upper part of the frame 1, and a seat rail 2 is provided. A substay 3 is installed between the base of the rail 2 and the rear part of the frame 1 for reinforcement. A bracket 4 is fixed to the rear lower part of the frame 1, to which the front end of a swing arm 5 is pivotally mounted 6, and a rear wheel 7 is mounted and supported at the rear end of the swing arm 5.

A rear action unit 8 is arranged between the swing arm 5 and the seat rail 2. As shown in FIG. 2, this rear action unit 8 consists of a damper 801 and a spring 802. A piston rod 804 is inserted from above into an inner cylinder 803 constituting the damper 801, and the inner cylinder is inserted into the lower end of the piston rod 804. A piston 805 that partitions the inside of 803 into upper and lower oil chambers S ₁ and S ₂ is fixed.

Further, an outer cylinder 806 is integrally formed on the outside of the inner cylinder 803, and the outer periphery of the inner cylinder 803 and the outer cylinder 80
The oil chamber S ₃ formed between the inner circumferences of 6 communicates with the oil chamber S ₂ through an oil hole 807, and the cylindrical portion of the lower seat 808 is slid into the oil chamber S ₃ from above via a seal member. It can be fitted freely.

On the other hand, the upper end of the piston rod 804 is connected to an upper metal 809, and an upper seat 810 of the spring 802 is connected to this upper metal.
is installed. Thus, the spring 802 is held between the upper seat 810 and the lower seat 808.

Further, the middle or lower part of the damper 801 is loosely suspended in a space between cross members provided at the front part of the swing arm 5, and one end of the bell-shaped link 9 is connected to a bracket 502 hanging from the middle part of the swing arm 5. The other end of the link 9 is connected to a damper 80.
81 is pivoted to a bracket 815 provided at the lower end of 1.
6. The intermediate portion of the link 9 is pivotally connected to the other end of a regulating link 10 whose one end is pivotally connected 101 to the lower rear portion of the frame 1.

In the above, the impact from the rear wheel 7 is buffered by swinging the swing arm 5 around the support shaft 6, but the swing of the swing arm 5 supports the link 9 while being regulated by the regulation link 10. It swings about the shaft 503 and presses the damper 801, which is pivotally supported by the support shaft 816, in the axial direction, and the damping force is progressively changed by the operation of the link 9. On the other hand, when the damper 801 is pushed upward by the operation of the link 9, the piston 80 in the inner cylinder 803
5 is pushed down, and the oil in the inner cylinder 803 flows through the oil hole 807 to the outer cylinder 806.
It moves to the side oil chamber _S3 , and the lower seat 808 is pushed upward, resulting in a compression motion being applied to the spring 802. Therefore, the spring 80
2, since the lower seat 808 is movable, the damper 801
It acts independently while cooperating with the damper 80.
1 and spring 802 have different rates of change due to their respective progressive movements. Note that a desired stroke can be obtained by appropriately selecting the volume ratio between the oil chambers of the outer cylinder 806 and the inner cylinder 803.

By the way, in the conventional progressive shock absorber, the spring 802 and damper 801 that make up the rear action unit 8 behave in a fixed manner because the damper and lower seat are integrated. The areas where both can be achieved will be limited. However, in the present invention, the spring 802 and the damper 801 behave separately, so for example, as shown in FIG. 3A, the rate of change of the spring 802 is increased to soften the riding load, and the rate of change of the damper 801 is adjusted to the lever ratio. On the other hand, it is possible to prevent excessive damping or insufficient damping force by making the damping force linear.

(Effects of the invention) As detailed above, according to the invention, in a suspension system that progressively changes the buffering force, it is possible to select a preferable rate of change for each of the spring and damper, thereby further improving the riding comfort of motorcycles and tricycles. It is possible to improve the stability and reproducibility.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is a side view schematically showing the suspension system according to the present invention, Fig. 2 is an enlarged view of the same main part, and Fig. 3 A and B are springs and dampers. Graph showing desirable characteristics of 4th
The figure is a side view of a conventional example. In the drawings, 1 and 2 are the vehicle body, 5 is the swing arm, 7 is the rear wheel, 8 is the rear action unit, and 8 is the rear wheel.
01 is a damper, 802 is a spring, 803 is an inner cylinder, 806 is an outer cylinder, 8
08 is the lower seat.

Claims (1)

[Scope of utility model registration request] The rear wheel is supported by a swing arm, one end of a rear action unit consisting of a spring and a damper is pivotally connected to the vehicle body, and the other end of the rear action unit is pivotally connected to the swing arm either directly or through a link. In rear wheel suspension systems for motorcycles, tricycles, etc., the damper has an inner cylinder and an outer cylinder, and a piston fixed to a piston rod is slidably provided in an oil chamber in the inner cylinder. The oil chamber formed between the inner cylinder and the outer cylinder communicates with the oil chamber in the inner cylinder, and the lower seat of the spring is slidably fitted into the oil chamber formed between the inner cylinder and the outer cylinder. A rear wheel suspension system for motorcycles, tricycles, etc., characterized by a rear wheel suspension system for motorcycles, tricycles, etc.