JPH0416792Y2 - - 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 rear fork 5
A suspension system in which the cushioning characteristic of the cushion unit 55 is made progressive (gradual increase) 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

By the way, when gradually changing the buffer characteristics,
If the spring constant suddenly rises from a certain stroke and changes, you will experience this in the rising part and this is not desirable.On the other hand, if the spring constant changes in a straight line, it will be easier to bottom out, or when the ride is around 1G. The ride comfort lacks a soft feeling, which is not desirable. 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 developed to solve the above technical problems, and its purpose is to gradually change the spring characteristics suitable for the spring characteristics of the spring and the damping force characteristics of the damper, thereby improving ride comfort and handling. To provide a progressive type suspension device with further improved safety.

(Means for solving the technical problems) In order to solve the above technical problems, the present invention supports the rear wheel with a swing arm, and pivots one end of a rear suspension unit consisting of a spring and a damper on the vehicle body side. In a rear wheel suspension system for motorcycles, tricycles, etc., in which the other end of the rear suspension unit is pivotally connected to a link movably connected to the swing arm side, the lower seat of the spring is slidable on the outer periphery of the damper housing. The cam portion of the link that is fitted and supports the lower end of the damper is engaged with the lower surface of the lower seat, and the lower seat is operated by this cam behavior, so that the damper and the spring can be operated independently.

(Function) According to the above means, the damper and the spring are separately supported by the progressive link mechanism, and the respective rate of change can be set to the optimum 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 side view of an embodiment of the rear wheel suspension system according to the present invention, in which 1 is a frame of a motorcycle, and a seat rail 2 extends rearward from the rear upper part of the frame 1. A substay 3 is installed between the base 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.

The suspension system is shown on an enlarged scale in FIG. 2, and numeral 8 indicates a rear suspension unit.

The rear action unit 8 consists of a damper 801 and a spring 806. A piston rod 803 housed in the housing extends upward from the upper end of a bottomed cylindrical damper housing 802, and a bracket 804 is fixed to the upper end of the rod 803. established,
The bracket 804 is pivotally attached 202 to a bracket 201 that projects downward from the seat rail 2. A hot seat 805 of a spring 806 is attached to the bottom surface of the bracket 804 of the rod 803, and
03 and a coil spring-like spring 806 provided so as to surround the damper housing 802. The upper end portion of the spring 806 is supported by a top sheet 805.

A disk-shaped annular lower seat 807 is slidably fitted around the middle portion of the damper housing 802.
The lower end of the spring 806 is supported by the lower seat 807.

The middle or lower part of the damper housing 802 is loosely suspended in a space 501 between cross members provided at the front of the swing arm 5, and the base end of the bell-shaped link 9 is connected to a bracket 502 hanging from the middle part of the swing arm 5. 901 is pivotally attached 503, and the link 9 has a front arm portion 902 pivotally attached 810 to the lower end portion of the damper housing 802, and has a cam portion 903 at the tip thereof, and the lower surface of the lower seat 807 is brought into contact with and supported by the cam portion 903. ing. Then, the V-shaped middle point 905 of the link 9 is pivotally attached 102 to the other end of the regulating link 10 whose one end is pivotally attached 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 a shaft 503, presses a damper 801 pivoted on a support shaft 810 in the axial direction, and changes the damping force progressively by the operation of the link 9. On the other hand, link 9
The lower seat 807 that engages with the cam portion 903 of
Since it is swingable relative to the damper housing 802, it is compressed. Therefore, since the lower seat 807 is movable, the spring 806 acts independently while cooperating with the damper 801, and since each lever ratio is different, the rate of change due to each progressive movement is different.

By the way, in the conventional progressive shock absorber, the spring 806 and the damper 801 that make up the rear action unit 8 behave in a fixed manner because the damper housing and the lower seat are integrated. The areas where both can be achieved will be limited. In the present invention, each behaves separately and operates as a buffer at different rates of change. Since the spring 806 does not depend on speed, the gradual increase rate of change is large to soften the riding load.
It is preferable to increase the spring constant for large loads, and as shown in FIG. 4A, the rate of change in the lever ratio can be increased as the stroke progresses. On the other hand, the damping force of the damper 801 may become over-damped or insufficient in a certain region depending on the rate of change, so it is better to keep the rate of change linear with the lever ratio and not too large, as shown in Figure 4B. preferable.

In the present invention, since the progressive link mechanism allows the rear action unit 8 to behave by changing the lever ratio of the damper and spring separately, preferred rates of change are individually set for each of the above, and preferred damping characteristics are imparted to each. be able to.

(Effects of the invention) As detailed above, according to the invention, in a suspension system that progressively changes the buffering force, the preferable rate of change of each of the spring and damper can be selected by the link mechanism, which improves the riding performance of motorcycles and tricycles. It is possible to improve comfort and maneuverability.

[Brief explanation of the drawing]

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 main part, and Fig. 3 is a part of Fig. 2. 4A and 4B are graphs showing preferable characteristics of the spring and damper, and FIG. 5 is a side view of a conventional example. In the drawings, 1 and 2 are the vehicle body, 5 is the swing arm, 8 is the rear action, 801 is the damper, and 80
2 is a damper housing, 806 is a spring, 8
07 is a lower seat, 9 is a link, and 903 is a cam portion.

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 attached to a link movably connected to the swing arm. In a pivoted rear wheel suspension system for a motorcycle, tricycle, etc., the lower seat of the spring is slidably fitted into the housing of the damper, and the lower surface of the lower seat is connected to the cam of the link that pivotally supports the lower end of the damper. 1. A rear wheel suspension device for a motorcycle, tricycle, etc., characterized in that the rear wheel suspension device for a motorcycle, tricycle, etc. is supported in contact with a damper and a spring so that a damper and a spring can move independently.