JP2732388B2 - Rear wheel suspension for motorcycles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle rear wheel suspension device for suspending a rear wheel from a body frame in a motorcycle.

(Prior art) Conventionally, the motorcycle rear wheel suspension system has
-13387.

According to this, a rear arm whose front end is pivotally supported by the body frame and whose rear end is swingable up and down is provided.
The rear arm includes a pair of left and right arm portions, and a cross member that connects the intermediate portions between the front and rear portions of each of the arm portions to each other. A rear wheel is disposed between the rear portions of the two arm portions, and the rear wheel is supported on rear end portions of the two arm portions. Further, a link mechanism is provided below the arms to connect a middle part of each arm and the vehicle body frame, and a link mechanism penetrates between the front portions of the two arms, and A shock absorber is provided between the frame and the link mechanism.

Then, when the rear wheel receives an impact from the traveling surface and the rear arm rotates upward while the motorcycle is running, the link mechanism increases the reduction amount of the shock absorber nonlinearly as the rear arm rotates upward. That is,
Thereby, the followability of the rear wheel to the running surface is improved.

Further, in the conventional technique, a reinforcing plate having an opening through the middle of the shock absorber and connecting the front portions of the arm portions to each other, the rear wheel, the shock absorber and the link mechanism There are provided a rear plate for partitioning the space, and a pair of left and right side plates for covering the shock absorber and the link mechanism from the outside thereof.

For this reason, it is suppressed by the rear plate that the pebbles and mud, etc., which the rear wheel jumps up while traveling, attempt to collide with the shock absorber and the link mechanism, thereby protecting the shock absorber and the link mechanism. .

In addition, since each lower end of the shock absorber and the link mechanism is located near the running surface, it is easy to come into contact with an obstacle on the running surface, but this contact is suppressed by the side plates, thereby Also, the shock absorber and the link mechanism are protected.

(Problems to be Solved by the Invention) By the way, pebbles flipped up by the rear wheel and obstacles on the running surface collide with the shock absorber and the link mechanism.
In particular, it is considered that the rear plate and the side plate are not provided under the rear arm, so that the shock absorber and the link mechanism are protected from the collision. It may be insufficient.

On the other hand, it supports the rear arm body,
Since a large external force is applied, it is desired to further improve the strength of the rear arm with a simple configuration.

(Object of the Invention) The present invention has been made in view of the above circumstances, and pebbles flipped up by a rear wheel and obstacles on a running surface collide with a shock absorber and a link mechanism and are damaged. It is an object of the present invention to more reliably prevent the rear arm from being moved, and to further improve the strength of the rear arm with a simple configuration.

(Structure of the Invention) A feature of the present invention to achieve the above object is that a rear arm 11 whose front end is pivotally supported by a body frame 2 and whose rear end is swingable up and down is provided. The rear arm 11 includes a pair of left and right arms 13, 13, and a cross member 14 for connecting the intermediate portions between the front and rear portions of each arm 13 to each other. A rear wheel 16 is disposed between the two arms 13 and 13, and the rear wheel 16 is supported by the rear ends of the arms 13 and 13. A link mechanism 18 is provided to connect the middle part and the vehicle body frame 2, and a shock absorber 17 that extends between the body frame 2 and the link mechanism 18 through the front portion of the arms 13, 13 is provided. A front portion of each of the arm portions 13 having an opening 15a through which a middle portion of the shock absorber 17 is provided. Reinforcing plate to be connected to each other
15, a rear part 45 for partitioning between the rear wheel 16 and the shock absorber 17 and the link mechanism 18, and a rear part 45 for separating the shock absorber 17 and the link mechanism 18 from each other.
A rear wheel suspension device provided with a pair of left and right side plates 46, 46 for covering the rear plate 45 from outside thereof. (1) The rear plate 45 is projected downward from the cross member 14 and The side plates 46 are projected downward from the front portions of the respective arm portions 13 respectively, and the rear plate
Connect each side end of 45 and the rear end of each side plate 46 to each other,
Further, a front plate 44 is provided that has an opening 44a that penetrates each halfway portion of the shock absorber 17 and the link mechanism 18 and that connects the front ends of the side plates 46 to each other. A U-shaped stay 48 which is located on the lower side and opens rearward in plan view is provided, and the lower end of the rear plate 45 is supported by the rear end of each of the arms 13 by this stay 48. On the point.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

2 and 3, reference numeral 1 denotes a motorcycle, 2 denotes a vehicle body frame, and the vehicle body frame 2 has a pair of left and right main frames 4 which are lowered backward and left and right from the rear end of the main frames 4. A pair of rear arm brackets 6 extend downward.

A seat rail 7 extends rearward and upward from a rear portion of the main frame 4, and the rear portion of the seat rail 7 is supported on an upper portion of each rear arm bracket 6 by a back stay 8.

A circular end of a rear arm 11 is pivotally supported by a pivot shaft 10 on the rear arm brackets 6, 6, and a rear end thereof is swingable up and down. The rear arm 11 is
A pivot pipe 12 is supported coaxially with the pivot pipe 12 so as to be rotatable around the axis. A pair of left and right arms 13 extends from the pivot pipe 12 toward the rear.

A cross-member 14 made of a connection pipe is provided for firmly connecting the middle portions between the front and rear portions of the arms 13 and 13 to each other. Further, a reinforcing plate 15 is provided for connecting the front portions of the arms 13, 13 to each other, the pivot pipe 12, and the cross member 14, and the reinforcing plate 15 has an opening 15a. A rear wheel 16 is disposed between the rear portions of the arms 13 and 13, and the rear wheel 16
The rear ends of the 13, 13 are supported by a rear axle 16a. The upper end of the rear arm bracket 6 and the rear arm 15
A shock absorber 17 is interposed with the link mechanism 18 between them, which will be described later.

Reference numeral 19 denotes a two-stroke two-cylinder engine, which is supported on the body frame 2 by bolts 20. This engine 19
Is provided with a drive chain wheel 21, while the rear wheel 16 is a driven chain wheel
A transmission chain 23 is wound around the two chain wheels 21 and 22. In addition, 24 is a fuel tank, 25 is a main seat, and 26 is a passenger seat.

Then, the transmission chain 23 is driven by the driving of the engine 19.
If the rear wheel 16 is driven via the like, the motorcycle 1 can travel.

The shock absorber 17 and the link mechanism 18 will be described in more detail with reference to all the drawings.

The shock absorber 17 includes an extendable hydraulic cylinder-shaped damper 27,
A spring 28 that urges the damper 27 in the extending direction
It is composed of The upper end of the damper 27 is pivotally supported on the upper end of the rear arm bracket 6 by the first support shaft 29,
These dampers 27 and springs 28
Through the opening 15a.

On the other hand, the lower ends of the left and right rear arm brackets 6, 6 are firmly connected to each other by a rectangular pipe-shaped cross pipe 30, whereby the rigidity of the vehicle body frame 2 is increased. Also, a pair of brackets is attached to the cross pipe 30.
31,31 are welded.

The link mechanism 18 is located below the arms 13 and connects the middle part of each arm 13 to each bracket 31 of the vehicle body frame 2 via the cross member 14. More specifically, the link mechanism 18 has a main link 33 pivotally supported on the left and right brackets 31 and 31 by a second support shaft 32 so as to be vertically rotatable. The lower end of the damper 27 of the shock absorber 17 is pivotally supported by a third support shaft 34. A pair of left and right connecting links 36, 36 are pivotally supported by a fourth support shaft 37 in the front and rear halfway of the main link 33, and the rotating ends of the connecting links 36, 36 project from the lower surface of the cross member 14. The bracket 38 is pivotally supported by a fifth support shaft 39.

Then, the shock absorber 17 buffers an impact transmitted from the running surface 41 to the vehicle body frame 2 through the rear wheel 16 and the rear arm 11, and at this time, the link mechanism 18 operates as follows. That is, when the rear wheel 16 receives an impact from the traveling surface 41 during the traveling of the motorcycle 1 and the rear arm 11 rotates upward,
The link mechanism 18 nonlinearly increases the amount of reduction of the damper 27 as the rear arm 11 rotates upward, thereby
The followability of the rear wheel 16 to the running surface 41 is improved.

In the above configuration, a reinforcing member 42 for reinforcing the rear arm 11 is provided on the lower surface side of the rear arm 11. The reinforcing member 42 has an inverted triangular shape in side view and a rear arm.
It protrudes downward from the lower surface of 11. Rear arm 11
The main body 43 of the reinforcing member 42 protruding from the lower surface of the front part is made of sheet metal and has a box-shaped cross section in plan view.
5 and left and right side plates 46, 46 for connecting the left and right side ends of both plates 44, 45, the lower end of which extends to near the lower end of the link mechanism 18.

The upper end of the front plate 44 is welded to the pivot pipe 12 so as to be lowered downward.An opening 44a is formed in the front plate 44, and the opening 44a is connected to the shock absorber 17, the left and right connecting links 36, 36 midway sections are penetrated.

On the other hand, the upper end of the rear plate 45 is welded to the cross member 14 and protruded downward from the cross member 14. The rear surface of the rear plate 45 is formed as a concave surface 45a to prevent contact with the rear wheel 16. Have been. Also, in this case, this back plate
Reference numeral 45 is a partition between the rear wheel 16 and the link mechanism 18, that is, pebbles and the like that the rear wheel 16 jumps up are the shock absorber 17 and the link mechanism.
The collision with 18 is prevented.

The upper ends of the left and right side plates 46, 46
And is projected downward from the front part of each of the arm portions 13 so that each side end of the rear plate 45 and the rear end of each side plate 46 are connected to each other. Have been.
Each of the side plates 46 covers a lower portion of the shock absorber 17 and an upper portion of each connection link 36 from outside thereof. That is,
Each side plate 46 prevents the shock absorber 17 and the link mechanism 18 from contacting an obstacle on the running surface 41.

In the above case, the front plate 44 connects the front ends of the side plates 46 to each other. Also, the fifth support shaft is provided on each of the side plates 46.
A through-hole 46a is formed coaxially with 39.
A rubber cap 46b for opening and closing 6a is provided. When the cap 46b is removed, the fifth support shaft 39 can be detached from the connection link 36 or the bracket 38 through the through hole 46a.

A U-shaped stay 48 is provided below the arm 13 of the rear arm 11 and opens rearward in a plan view. With this stay 48, the lower end of the main body 43 including the rear plate 45 is firmly supported by the rear end of each arm 13. A middle part of the stay 48 in the front-rear direction is firmly supported by each arm 13 by a support member 49.

(Effects of the Invention) According to the present invention, a rear arm whose front end is pivotally supported by the body frame and whose rear end is swingable up and down is provided.
The rear arm includes a pair of left and right arm portions, and a cross member that connects the middle portions between the front and rear portions of the respective arm portions to each other, and a rear wheel is disposed between the rear portions of the two arm portions. Along with this rear wheel, the both arm portions are supported at the rear end portions, and a link mechanism is provided below the respective arm portions to connect a middle portion of each of the arm portions and the vehicle body frame, A shock absorber is provided which extends between the front portions of the both arm portions and is bridged between the vehicle body frame and the link mechanism. A reinforcing plate for connecting them to each other, a rear plate for partitioning between the rear wheel, the shock absorber and the link mechanism, and a pair of left and right side plates for covering the shock absorber and the link mechanism from the outside thereof; Is a “precondition” and (1) The rear plate protrudes downward from the cross member, and the side plates protrude downward from the front part of each arm, respectively, and the side end of the rear plate and the rear end of each side plate. And a front plate that has an opening that penetrates the intermediate portion of the shock absorber and the link mechanism and that connects the front ends of the side plates to each other, has the following effects.

That is, it is easy for the pebbles flipped up by the rear wheels and obstacles on the running surface to collide with the shock absorber and the link mechanism, particularly under the rear arm, but according to the above configuration, The shock absorber and the link mechanism are covered by the front plate, the rear plate, and each side plate from the front and rear and left and right below each arm portion of the rear arm. Protected from collisions which are likely to occur on the side, preventing its damage.

Moreover, the "combination body" of the front plate, the rear plate, and the respective side plates, and the reinforcing plate has a box shape, which has a high strength and sufficiently opposes the collision. .

Therefore, the shock absorber and the link mechanism are more reliably protected, and the damage is more reliably prevented.

(2) In addition, it is located below each of the above arm portions,
A U-shaped stay that opens rearward in a plan view is provided, and the lower end of the rear plate is supported by the rear end of each of the arm portions by this stay.

For this reason, in a side view, the "combination body" formed by the arm portion, the front plate, and the like, and the stay form an inverted substantially triangular frame, which has a high strength, and has a high strength. It will be enough to oppose. In addition, the front portion of the stay has an arc shape in plan view, and when colliding with an obstacle on the running surface, the obstacle is smoothly guided outward to reduce the impact force.

Therefore, the protection of the shock absorber and the link mechanism is further improved, and the damage is more reliably prevented.

Further, according to the above configuration, a “combination body” such as a front plate for preventing damage to the shock absorber and the link mechanism,
By using the stay, the strength of each arm is improved, that is, the strength of the rear arm is improved by a simple configuration.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a partially enlarged view of FIG. 2, FIG. 2 is a rear side view of a motorcycle, and FIG.
FIG. 4 is a view taken along line III-III, FIG. 4 is a view taken along line IV-IV in FIG. 1, and FIG. 5 is a view taken along line VV in FIG. 1 ... motorcycle, 2 ... body frame, 6 ... rear arm bracket, 11 ... rear arm, 13 ... arm part,
14 …… Cross member, 15 …… Reinforcement plate, 15a …… Opening, 16
...... Rear wheel, 17 ... shock absorber, 18 ... link mechanism, 19 ... engine, 42 ... reinforcement member, 44 ... front plate, 44a ... opening, 4
5 ... rear plate, 46 ... side plate, 48 ... stay.

Claims (1)

(57) [Claims] 1. A rear arm having a front end pivotally supported by a body frame and a rear end swingable up and down is provided. The rear arm includes a pair of left and right arm portions, and a front portion and a rear portion of each of these arm portions. A cross member for connecting the intermediate portions between the two arms to each other, a rear wheel is disposed between the rear portions of the two arm portions, and the rear wheel is supported on the rear end portions of the two arm portions. A link mechanism that is located below each arm and connects a middle part of each arm to the vehicle body frame; A reinforcing plate having an opening through the middle of the shock absorber and connecting the front portions of the arm portions to each other, the rear wheel, the shock absorber and the link mechanism. And a rear plate separating between
A motorcycle rear wheel suspension device provided with a pair of left and right side plates that cover the shock absorber and the link mechanism from the outside thereof. (1) The rear plate protrudes downward from the cross member, and Each side plate is projected downward from the front portion of each of the arm portions, each side end of the rear plate and the rear end of each side plate are connected to each other, and each of the shock absorber and the link mechanism is A front plate is provided that has an opening through the middle part and connects the front ends of the side plates to each other. (2) It is located below the arm portions and opens rearward in plan view. A rear wheel suspension system for a motorcycle, comprising a U-shaped stay, the lower end of the rear plate being supported by the rear end of each of the arms by the stay.