JPS60234088A - Suspension system for rear wheel of motorcycle - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rear wheel suspension system for a motorcycle having a structure in which a link mechanism is provided between a shock absorber and a swinging arm.

(Prior Art) Conventionally, motorcycles are equipped with a rear wheel suspension system in order to absorb the impact that the rear wheels receive from the road surface while driving. The rear wheel suspension system is such that the front end of a swing arm having a rear axle attached to the rear end is pivotally connected to the middle part of the body frame, and a shock absorber is installed between the upper part of the body frame and the middle part of the swing arm. There is something set up. In this type of rear wheel suspension system, when the rear wheel receives an impact from the road surface while driving and the swing arm rotates one turn in the downward direction, the piston to the shock absorber performs compression and tension movements, causing It is designed to attenuate the impact from Regarding the piston beat of such a shock absorber, in general, the actual A11
l value 0.3m/s ~1. Om/s steel (7), whereas in compression operation the actual value is 0.8m/s ~ 3.0m/s
The piston speed of the shock absorber is greater during compression operation than during tension operation.

(Problems to be Solved by the Invention) By the way, when the piston to the shock absorber performs a compression operation at a high speed, the piston operates while swinging in a bending direction with respect to the center direction of the shock absorber.

For this reason, during the compression operation of the shock absorber, the friction of the piston becomes extremely large, and there is a problem in that the smooth operation of the piston is significantly hindered. By the way, the position where the vibration of the piston is the largest is when the length of the shock absorber is 30% to 5% of the length at maximum extension.
This is when it becomes 0%.

(Means for Solving the Problems) The technical means of the present invention is to provide a rear axle at the rear end of a swing arm whose front end is pivotally connected to the vehicle body frame, and to attach a shock absorber to the -L portion of the vehicle body frame. In a type of rear wheel suspension system in which parts are pivotally connected, a link mechanism is disposed between the middle part of the swing arm and the lower part of the shock absorber,
When the swing arm rotates upward, the lower part of the shock absorber is pulled downward.

In this way, when the swing arm rotates upward,
When the lower part of the shock absorber is pulled downward, the vibration in the bending direction is smaller when the shock absorber is in tension than when it is in compression, so friction is kept small and smooth operation of the shock absorber is ensured. It happens.

(Example) An example of the present invention will be explained below with reference to the drawings.
In the figure, ■ is a motorcycle body claim, and 2 is a swing arm whose front end is pivotally connected via a shaft 3 to the middle part of a heavy frame 1.

A rear axle (not shown) is inserted through and supported by the rear end of the swing arm 2. An upper portion of a shock absorber 4 is pivotally attached to an upper portion of the vehicle body frame l. The first link 5 is attached to the shock absorber/<-4 piston rod 4a.
The front end of the first link 5 is pivotally connected, and the rear end of the first link 5 is pivotally connected to the intermediate portion of the swing arm 2 via a shaft 6. 1st
The upper end of the second link 7 is pivotally connected to the middle part of the link 5 via a shaft 8, and the lower end of the second link 7 is connected to the lower part of the body frame l than the swing arm 2 via the shaft 9. It is pivoted to.

As shown in FIG. 2, this second link 7 has its lower end pivotally connected to the middle part of the first link 5 by a shaft 8, and its upper end is connected to the swing of the vehicle body frame 1 by a shaft 9. It may also be pivotally attached to a portion above the arm 2.

In such a configuration, when the rear wheel receives an impact from the road surface while driving and the swing arm 2 rotates upward around the shaft 3, the second link 7 rotates counterclockwise around the shaft 9. As the first link 5 rotates, the first link 5 rotates counterclockwise around the shaft 8, and the shock absorber 4 swings to the left in the figure while the piston rod 4a is pulled downward to provide lth shock absorption. .

That is, the piston rod 4a of the shock absorber 4 acts in the opposite direction (pulling direction) to that of the conventional shock absorber. Therefore, even when the piston speed of the shock absorber 4 is high (when the swing arm 2 rotates upward), the shock absorber 4 swings as the swing arm 2 rotates. /The friction of the rod 4a becomes considerably small, and the shock absorber 4 provides a very smooth buffering action.

In the embodiment shown in FIG. 1, the shock absorber 4 is disposed above the front end of the swing arm 2, so that the effective space in the center of the vehicle body frame l is large.

FIG. 3 shows another embodiment of the present invention, in which the same components as in FIG. 1 are given the same reference numerals and their explanations will be omitted. The difference from the above embodiment is that the front end of the first link 5 is pivotally connected to the vehicle body frame l, and the rear end of the first link 5 is connected to the piston rod 4a of the shock absorber 4.
The lower end of the second link 7, which is pivoted to the middle part of the first link 5, is pivoted to the middle part of the swing arm 2. Even with this configuration, when the swing arm 2 rotates upward, the piston rod 4a of the shock absorber 4 is pulled downward via the first link 5 and the second link 7, and the shock absorber 4 will be ensured to operate smoothly.

(Effects of the Invention) As described above, according to the present invention, when the swing arm rotates upward, the shock absorber performs a tensile action, so even if the piston speed of the shock absorber is high, friction can be kept low. , the shock absorber operates more smoothly than before, improving the buffering effect.

[Brief explanation of drawings]

FIG. 1 is a side view showing one embodiment of the present invention, and FIG. 2 is a side view showing one embodiment of the present invention.
FIG. 3 is a schematic mechanical diagram showing a modification of the one shown in the figure. FIG. 3 is a schematic mechanical diagram showing another embodiment of the present invention. 1... Vehicle body frame 2... Swing arm 4...
・Shock absorber 4a...Piston rod 5...First link 7・
...Second link license applicant Suzuki Motor Co., Ltd. (and one other person) Fang 1 Fig. Fang 2 Fig. '73

Claims (1)

[Claims] (+) A rear axle is attached to the rear end of a swing arm whose front end is pivotally connected to the vehicle body frame, an upper part of a shock absorber is pivotally connected to the upper part of the vehicle body frame, and a lower part of the shock absorber and the A link mechanism is provided between the intermediate portion of the swing arm, and the shock absorber is moved through the link mechanism when the swing arm rotates upward;
A rear wheel suspension system for a motorcycle, characterized in that a lower portion of the shock absorber is connected to the shock absorber so as to be pulled downward. (2) A first link having one end pivotally attached to the lower part of the shock absorber and the other end pivotally attached to the middle part of the swing arm, and one end attached to the middle part of the first link. 2. The rear wheel suspension system for a motorcycle according to claim 1, further comprising a second link which is pivotally connected and whose other end is pivotally connected to the vehicle body frame. (3) The link mechanism includes a first link whose one end is pivotally connected to the lower part of the shock absorber and whose other end is pivotally connected to the vehicle body frame, and one end which is pivotally connected to the intermediate part of the first link. and a second end whose other end is pivotally connected to the intermediate portion of the swing arm.
A rear wheel suspension system for a motorcycle according to claim 1, characterized in that the rear wheel suspension system for a motorcycle is constituted by a link.