JPS6325993B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention employs a progressive link mechanism that can progressively increase the compression stroke of the rear wheel shock absorber as the swing stroke of the rear wheel support member increases. This invention relates to a rear wheel shock absorber for a motorcycle.

A rear wheel support member whose rear end supports the rear wheel and whose front end is pivotally connected to the vehicle body frame so as to be able to swing up and down, absorbs and cushions the rocking of the rear wheel support member about the front end and the rear wheel due to road surface undulations. A progressive link mechanism type rear wheel shock absorber for a motorcycle is known. In the progressive link mechanism type rear wheel shock absorber, one end of the rear wheel shock absorber is connected to the vehicle body frame, and the other end of the rear wheel support member is connected via the first link, and the vehicle body frame and the rear wheel support member are connected via the first link. The first link is connected by the second link. When the rear wheel support member swings upward, the shock absorber is compressed via the first link, and the first link is rotated by the second link around the connection with the rear wheel support member. , the compression stroke of the shock absorber is the addition of the rotation amount of the first link, and as a result, the shock absorber's shock absorbing force characteristic has a progressive characteristic that increases in a quadratic curve as the swinging stroke of the rear wheel support member increases. becomes.

By the way, in a motorcycle equipped with a rear wheel shock absorber that employs such a progressive link mechanism, it is necessary to arrange the first and second links on the vehicle body, but the vehicle body also has equipment necessary for the motorcycle, For example, since air cleaners, batteries, etc. are installed, the positional relationship of the first and second links and shock absorbers is determined rationally to ensure space for these devices, and a progressive link mechanism rear wheel is installed. It is required to make the shock absorber more compact as a whole. In addition, since a motorcycle performs a bank operation to tilt the vehicle body in the turning direction when turning, it is necessary to install a muffler, a stand, etc. placed on the underside of the rear wheel support member in order to obtain the necessary vehicle body inclination angle, that is, the bank angle. Rear wheel shock absorbers are required to take into consideration components, equipment, etc.

The present invention has been made to effectively meet the above demands.

An object of the present invention is to connect the front end of a rear wheel support member that supports a rear wheel to a vehicle body frame so as to be able to swing vertically;
A rear wheel of a motorcycle in which the other end of a shock absorber whose one end is connected to the body frame and the rear wheel support member are connected via a first link, and the body frame and the first link are connected by a second link. In the shock absorber, the first and second links are arranged on the upper surface side of the rear wheel support member, and are used for parts such as mufflers and stands, equipment, etc. arranged on the lower surface side of the rear wheel support member. A rear wheel shock absorber for a motorcycle is provided in which the arrangement space is left open and the arrangement of these parts and equipment can be carried out without being affected by the first and second links to obtain the necessary bank angle. It's there to provide.

Another object of the present invention is to connect the first link to the rear wheel support member at the front and rear intermediate portions of the link, and to connect the second link to the rear of the first link.
By connecting the above-mentioned shock absorbers to the front part and making the shock absorbers and the second link intersect with each other laterally, it is possible to create a common side part in each arrangement space of the shock absorbers and the second link. To provide a rear wheel shock absorber for a motorcycle that is compact as a whole and does not restrict the arrangement of motorcycle equipment such as an air cleaner and battery by reducing the space occupied by a shock absorber and a progressive mechanism in a vehicle body. It's there.

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

Figure 1 is an overall side view of a motorcycle, in which the body frame 1 includes a main frame 2, a down tube 3,
It is composed of a bottom frame 4, a rear frame 5, a subframe 6, a seat rail frame 7, etc., and an engine 8 is mounted on the bottom frame 4. The axle 9a of the rear wheel 9 is the rear fork 1
The front end of the rear fork 10, which is supported on the rear end of the rear fork 10 and thus serves as a rear wheel support member, is pivotally connected to the vehicle body frame 1 by a pivot shaft 11 so as to be able to swing vertically. One rear wheel shock absorber 12 is disposed at or near the center in the width direction of the vehicle body, and the shock absorber 12 is disposed close to the vehicle center of gravity G, which is located near the engine 8. The moment of inertia around it is reduced.
The shock absorber 12 is attached to the vehicle body frame 1 by connecting the upper end of the shock absorber to the vehicle body frame constituent members around the lower part of the seat 13. It can swing freely.

As shown in FIG. 2, a first link 15 as a cushion arm is connected to and held by a stay 10a projecting from the upper surface of the rear fork 10 so as to be able to swing up and down through a shaft 16. 12 and the rear fork 10 are connected. Further, a stay 17a is provided on a cross bar 17 installed between the left and right rear frames 5, 5 to project rearward, and a front end of a second link 18 as a tension rod is connected to the stay 17a by a shaft 19. The rear end of the second link 18 is connected to the first link 15 by a shaft 20. As a result, the vehicle body frame 1 and the first link 15 are connected by the second link 18, and the first and second links 15 and 18 constitute a progressive link mechanism 21.

When the rear fork 10 swings upward about the pivot shaft 11 due to the movement of the rear wheel 9 following the road surface undulations, the shock absorber 12 is moved by the first link 15 that moves upward together with the rear fork 10.
is compressed, and since the distance between the shafts 19 and 20 is constrained to a constant by the second link 18, the second link 18, which rotates downward in an arcuate trajectory around the shaft 19, First link 1
5 is rotated clockwise about the shaft 16, so that the compression stroke of the shock absorber 12 is equal to the rocking stroke of the rear fork 10.
The buffering force characteristic of the shock absorber 12 becomes a progressive characteristic in which the compression stroke and the buffering force gradually increase as the swinging stroke of the rear fork 10 increases.

In the above description, like the shock absorber 12, the first and second links 15 and 18 are arranged on the upper surface side of the rear fork 10. For this reason, the space for components such as the muffler and stand placed on the bottom side of the rear fork 10 is limited to the progressive link mechanism 2.
1, and these members and the like can be rationally placed at a ground clearance position where the required bank angle for the motorcycle can be obtained.

As shown in FIG. 2, the first link 15 has an upwardly curved side surface shape, but its length direction is in the front-rear direction of the vehicle body, and is connected to the rear wheel support member 10 by a shaft 16 at the front-rear intermediate portion. The first link 15
A second link 18 is connected to the rear part of the link 18, a buffer 12 is connected to the front part of the link 1, and the buffer 12 and the second link 1
It intersects laterally with 8. As shown in FIG. 3, the second link 18 includes left and right side bars 18a, 18b, and
The stay 1 has a substantially H-shaped planar shape and includes a cross rod 18c that connects the side rods 18a and 18b, and the front ends of the side rods 18a and 18b are provided on the cross bar 17.
7a, 17a, and the rear end is connected to the first link 15.
connected to. The buffer 12 has side bars 18a and 18b.
The above-mentioned side crossing is achieved while ensuring the operation of the progressive link mechanism 21 and the expansion and contraction operation of the shock absorber 12.

Since the buffer 12 and the second link 18 are arranged as described above, the buffer 12 can be arranged in the dead space which is the original arrangement space of the second link 18. However, since the shock absorber 12 and the second link 18 are arranged with a common space on the side, the space occupied by the shock absorber 12 and the progressive link mechanism 21 in the vehicle body can be reduced, and as a result, the rear wheel shock absorber is compact. Therefore, a space can be left open for arranging equipment such as an air cleaner and a battery around the shock absorber 12 and the progressive link mechanism 21. In addition, since the shock absorber 12 laterally intersects with the front side of the second link 18 instead of the rear side, a large open space can be secured above the second link 18 and behind the shock absorber 12, and the shock absorber 12 can be brought closer to the center of gravity G of the vehicle, and the moment of inertia can be effectively reduced.

Furthermore, the first and second links 15 and 18 have a simple shape, and in particular, the second link 18 has a simple shape.
Although it has a shape that allows the shock absorber to penetrate vertically, it has great rigidity and can effectively support the load that acts when the shock absorber is compressed. In order to cross the shock absorber 12 laterally, the second link may have another shape, for example, a Y-shape in plan view.

In addition to the above, in the present invention, while maintaining the above-mentioned positional relationship between the first and second links 15 and 18 and the shock absorber 12, the length dimension of the first and second links 15 and 18, the distance between the axes, for example, the axis 16 , 20 can be arbitrarily set, so that the progressive characteristics of the shock absorber 12 determined by these length dimensions and the distance between the axes are desirable characteristics for the motorcycle to which the device according to the present invention is applied. The degree of freedom to set this will be guaranteed.

As is clear from the above description, according to the present invention, since the first and second links constituting the progressive link mechanism are arranged on the upper surface side of the rear wheel support member, the muffler, stand, etc. are arranged on the lower surface side of the rear wheel support member. Can be placed without being affected by the progressive link mechanism,
As a result, it is now possible to secure the bank angle necessary for a motorcycle. In addition, the second link is connected to the rear of the first link whose front and rear intermediate portions are connected to the rear wheel support member, and the shock absorber is connected to the front of the first link, and the shock absorber and the second link intersect with each other on the side, so that the vehicle body The space occupied by the shock absorber and progressive link mechanism can be reduced, and motorcycle equipment such as air cleaners and batteries can be placed more effectively around them.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention; FIG. 1 is an overall side view of a motorcycle, FIG. 2 is an enlarged view of the main part of FIG. 1, and FIG. 3 is a perspective view of FIG. 2. In the drawing, 1 is the vehicle body frame, 9 is the rear wheel, and 10 is the vehicle body frame.
1 is a rear fork which is a rear wheel support member, 12 is a shock absorber, 15 is a first link, and 18 is a second link.

Claims (1)

[Claims] 1. The front end of the rear wheel support member that supported the rear wheel is connected to the vehicle body frame so as to be able to swing vertically, and the other end of the shock absorber whose one end is connected to the vehicle body frame is connected to the rear wheel support member via a first link. In a rear wheel shock absorbing device for a motorcycle in which a vehicle body frame and the first link are connected by a second link, the first and second links are disposed on the upper surface side of the rear wheel support member, and the front and rear The second link is connected to the rear of the first link whose intermediate portion is connected to the rear wheel support member, and the shock absorber is connected to the front of the first link, and the shock absorber and the second link intersect with each other laterally. rear wheel shock absorber for motorcycles.