JPH0637192B2 - Rear wheel suspension system for motorcycles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rear wheel suspension system for a motorcycle.

[Conventional technology]

Conventionally, as a rear wheel suspension device that absorbs and alleviates the vertical swing of the rear wheel due to the rising of the road surface to prevent the vibration from propagating to the vehicle body, as shown in FIG. On the both sides of the vehicle body between the seat rail 4 and the support part of the rear wheel 3 at the rear end of the rear fork 2 which is a rear wheel support member pivotally supported by
As shown in FIG. 2, a conventional suspension type in which a pair of cushions 5 are respectively arranged, and as shown in FIG. 2, one cushion 6 is provided between the front position of the rear wheel 3 of the rear fork 2 and the seat rail 4 via a link 7. A mono-suspension type is generally used.

However, in the case of motorcycles with low seat height, conventional type and mono suspension type
The cushion stroke is likely to be restricted in size, and the mono suspension type is likely to be restricted in the arrangement of vehicle constituent parts 11 such as a battery.

Further, as shown in FIG. 3, there is known a type in which a cushion 9 is arranged below a vehicle body frame 1 on which an engine 8 is mounted, and the cushion 9 is connected to a rear foam 2 via a link 10. .

However, in this type, since the cushion 9 is arranged below the vehicle body frame 1 in which the engine 8 is mounted, the minimum ground clearance LC becomes small, and the minimum ground clearance I
When C is large, the engine 8 is in a high position and the center of gravity is high.

For this reason, as disclosed in JP-A-58-194678, a cushion is provided below the rear fork between the front end and the rear wheel of the rear fork and between the steps.
A type has been proposed in which the rear wheel support member is disposed substantially parallel to the vehicle body width direction in a side view.

[Problems to be Solved by the Invention]

However, this type can be applied to a motorcycle having a relatively large engine width such as a in-line 4-cylinder engine in which the crankshaft is arranged in the vehicle width direction without any problem, but a single cylinder or a V type 2 In a motorcycle equipped with an engine having a small vehicle body width direction such as a cylinder, the length of the cushion body in the vehicle body width direction is larger than the engine width, and a large bank angle that greatly affects the driving performance of the motorcycle cannot be secured. Occurs. However, the above-mentioned inconvenience is further exaggerated by disposing the cushion in the vehicle body width direction in the vicinity of the steps.

Therefore, the present invention can reduce the seat height, obtain a lower center of gravity, and further provide a cushion mechanism short in the front-rear direction of the vehicle body to achieve compactness and a large bank angle. The purpose is to provide a suspension system.

[Means for Solving the Problems]

In order to solve the above problems, the present invention pivotally supports a front end of a rear wheel support member that supports a rear wheel between rear ends of a pair of arms extending rearward of a vehicle body in a vertically swingable manner on a vehicle body frame. ,
In a rear wheel suspension system of a motorcycle, wherein a cushion for supporting the rear wheel support member is disposed in a lower portion of the vehicle body at a substantially center in a vehicle width direction and substantially horizontally in a side view in a vehicle front-rear direction. And the rear end of the cushion is pivotally supported at a substantially central portion of the rear wheel support member in the front-rear direction, and the first arm and the second arm are connected to the vehicle body frame below the cushion by bending portions. The cross-shaped link is pivotally supported by the bent portion with the first arm upward and the second arm rearward, and the front end of the cushion is pivotally supported by the end of the first arm. It is characterized in that the end portion of the arm is connected to the rear wheel support member via a swingable connecting rod arranged laterally of the cushion.

[Work]

As a result, even if the seat height is lowered, sufficient load clearance can be secured, the center of gravity can be lowered, and the bank angle can be increased. In addition, the cushion mechanism can be arranged short in the front-rear direction of the vehicle body, and can be made compact.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 4 to 6.

The motorcycle 20 includes a front wheel 22 that is steered by a handle 21 and a rear wheel 26 that transmits the rotation of the engine 23 by a drive shaft 25 that is inserted into one arm 24a of a rear fork 24 that is a rear wheel support member. It is configured to run with.

The rear fork 24 has a pair of arms including an arm 24a into which the drive shaft 25 is inserted and the other arm 24b, and a front end 24c of each arm 24a, 24b is pivotally supported on a body frame 27 so as to be vertically swingable. The rear wheel 26 is supported between the rear ends 24d.

Below the rear fork 24 between the front end 24c of the rear fork 24 and the rear wheel 26, one cushion 28 for supporting the rear fork 24 is provided.
It is disposed in the vehicle front-rear direction approximately in the center in the vehicle width direction between 4a and 24b and substantially parallel to the rear fork 24 in side view.

Below the cushion 28, a character-shaped link 31 that connects the first arm 31a and the second arm 31b at a bent portion is arranged with the first arm 31a facing upward and the second arm 31b facing backward. The doglegged link 31 is rotatably provided on the vehicle body frame 27 by pivotally supporting the bent portion on a bracket 27a provided below the pivot point of the rear fork 24 of the vehicle body frame 27.

A rear end 28a of the cushion 28 is attached to a bracket 30 provided on a cross member 29 which is provided at a substantially middle portion between the arms 24a and 24b of the rear fork 24 in the front-rear direction.
The front end 28b is also pivotally supported on the end of the first arm 31a of the doglegged link 31.

One end of a connecting rod 32 is connected to the end of the second arm 31b of the doglegged link 31, and the other end of the connecting rod 32 is a cross member that is installed in front of the cross member 29 of the rear fork 24. Bracket 3 provided on member 33
Connected to four. The connecting rod 32 is swingably arranged on the side of the cushion 28 to protect the cushion 28 from the side.

The operation of the shock absorber thus configured will be described with reference to FIG. 5. At the minimum load, the rear fork 24 is slightly tilted rearward, so that the cushion 28 has a rear end 28a. When the driver sits on the seat 35 and has a standard load in the state of the slightly-dashed double-dashed line, the rear fork 24 is in a substantially horizontal state,
The rear end 28a moves up to the solid line position, the connecting rod 32 rotates the link 31 counterclockwise, and the first arm 31a of the link 31 pulls the front end 28b of the cushion 28 so that the cushion 28 is substantially horizontal. To the state of.

At the time of maximum load, as the rear fork 24 is tilted slightly upward toward the rear, the rear end 28a further rises, and the rotation amount of the first arm 31a of the link 31 in the counterclockwise direction increases. By further pulling the front end 28b of the cushion 28, the cushion 28 further extends to perform a cushioning action.

In this way, the cushion 28 is arranged in the space between the vehicle body frame 27 below the rear fork 24 and the rear wheel 26 in the vehicle front-rear direction substantially parallel to the cushion 28 in a side view, and has a length required for the cushion. Since the stroke can be secured, the position of the seat 35 can be lowered, the center of gravity can be lowered, and the cushion mechanism can be arranged short in the front-rear direction of the vehicle body, so that the vehicle body can be made compact and the cushion mounting portion The structure can also be strengthened. Further, since the link mechanism for supporting and acting the cushion 28 is composed of the link 31 and the connecting rod 32, so-called unsprung weight can be reduced.

Moreover, since the cushion 28 is disposed in the substantial center of the lower portion of the rear fork 24 in plan view, a large bank angle can be secured.

[Effect of Invention]

As described above, according to the present invention, the cushion supporting the rear wheel supporting member is provided below the rear wheel supporting member supporting the rear wheel between the rear ends extending to the rear of the vehicle body, at the substantially center of the vehicle width direction, and the side surface The rear end of the cushion is pivotally supported substantially at the center of the rear wheel support member in the front-rear direction, and the first arm and the second arm are bent on the body frame below the cushion. The bent portion is connected to the first arm upward, the second arm is directed rearward, and the bent portion is pivotally supported, and the front end of the cushion is pivotally supported at the end of the first arm. Since the end of the arm is connected to the rear wheel support member via the swingable connecting rod arranged on the side of the cushion, the minimum ground clearance can be increased and the seat height can be lowered. A center of gravity can be achieved and a large bank angle can be secured.

Moreover, the cushion mechanism can be arranged short in the front-rear direction of the vehicle body, the vehicle body can be made compact, and the connecting rod can protect the cushion from the side.

[Brief description of drawings]

1 to 3 show a conventional motorcycle rear wheel suspension system. FIG. 1 is a side view of a conventional suspension type, FIG. 2 is a side view of a mono suspension type, and FIG. A side view of a type in which a cushion is disposed below a vehicle body frame equipped with an engine, FIGS. 4 to 6 show an embodiment of the present invention, and FIG. 4 is a side view of a motorcycle, and FIG. FIG. 6 is a side view of an essential part showing a state of cushioning action, and FIG. 6 is a sectional view taken along line VI-VI of FIG. 20 ... Motorcycle, 23 ... Engine, 24 ... Rear fork, 24a, 24b ... Arm, 24c ... Front end, 2
4d ... rear end, 26 ... rear wheel, 27 ... body frame,
28 ... Cushion, 31 ... Link, 31a ... 1st
Arm, 31b ... Second arm, 32 ... Connecting rod, 35 ...
Sheet

Claims (1)

[Claims] 1. A front wheel of a rear wheel supporting member which supports a rear wheel between rear ends of a pair of arms extending rearward of a vehicle body is pivotably supported on a vehicle body frame in a vertically swingable manner, and the rear wheel supporting member is provided. In a rear wheel suspension device of a motorcycle, wherein a cushion to be supported is arranged in the vehicle width direction substantially in the center in the vehicle width direction in the lower part of the vehicle body and in the vehicle body front-rear direction substantially horizontally in a side view. A rear end of the cushion is pivotally supported at a substantially central portion in the front-rear direction of the rear wheel support member, and a body-shaped frame below the cushion is provided with a character-shaped link connecting the first arm and the second arm with a bent portion. , The first arm upward, the second arm backward, and the bent portions are pivotally supported, the front end of the cushion is pivotally supported at the end of the first arm, and the end of the second arm is The rear wheel support member is provided via a swingable connecting rod arranged laterally of the cushion. Rear-wheel suspension system for a motorcycle, characterized in that the coupling.