JPH0495595A - Rear-wheel shock absorber for motorcycle - Google Patents

Abstract

PURPOSE:To dispense with a compression coil spring as well as to enlarge a part storage space in the rear of an engine by interposing a plate spring between a rear-wheel support member and a body frame to be positioned in the upper part, and installing this plate spring in a state of being bent in the longitudinal direction of a car body. CONSTITUTION:A rear wheel 8 is supported on a frame 1 free of vertical rocking motion around a pivot shaft 11 via a rear frame 9 as a rear-wheel support member, to which power of an engine 2 is transmitted by a chain 10. A rear-wheel shock absorber 12 supporting this rear arm 9 in a cushioning way is composed of a plate spring 13 set up at the right of the rear wheel 8 and a damper 14 damping a vibration in this spring 13. The plate spring is made up of forming a glass fiber reinforced plastic into a slender plate form along the fibrous direction, and the molding form is made up into an almost circular form bent with the longitudinal central part as the center. This plate spring 13 is clamped of its bend part to the body front side, and both the ends are locked to the car body by mounting brackets 15, 16 in a state of being situated at the body rear side.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rear wheel shock absorber for a motorcycle, and particularly to the structure of a shock absorbing member.

[Conventional technology]

Conventionally, a rear wheel shock absorber for a motorcycle uses a compression coil spring mainly made of metal such as spring steel as a shock absorbing member. In conventional motorcycles, one rear wheel shock absorber has been installed at the rear of the engine because of the increased weight of the compression coil spring. As a result, a heavy object can be positioned closer to the center of the vehicle body in the longitudinal direction, and the unsprung weight can be reduced. The structure of installing this type of rear wheel shock absorber is that its lower end is connected to the front part of the rear arm via a link or the like, and the upper end is pivoted to a cross member of the vehicle frame installed behind the engine. A method of supporting the
(See Publication No. 389).

That is, this type of rear wheel shock absorber was installed upright between the engine and the rear wheels. Furthermore, the rear wheel shock absorber of a scooter is interposed between the rear part of a unit swing type engine and a portion of the body frame extending above the engine, as disclosed in Japanese Patent Application Laid-Open No. 62178484, for example. Ta.

[Problem to be solved by the invention]

However, if the rear wheel shock absorber is installed in a standing position at the rear of the engine in a motorcycle, there is a problem in that the parts storage space behind the engine is narrowed by the rear wheel shock absorber. For this reason, parts such as an air cleaner that are normally placed there are restricted in their placement position, and their capacity cannot be increased. Also,
In scooters as well, parts such as an air cleaner are arranged in the space above the engine where the rear wheel shock absorber is located, and the rear wheel shock absorber imposes restrictions on the arrangement positions and dimensions of each component.

[Means to solve the problem]

The rear wheel shock absorber for a motorcycle according to the present invention includes a leaf spring interposed between a rear wheel support member and a body frame positioned above the rear wheel support member, and a leaf spring that damps vibrations of the leaf spring. The damper is constructed of a damper, and the leaf spring is interposed in a state where it is curved in the longitudinal direction of the vehicle body.

[For production]

The rear wheel shock absorber for a motorcycle according to the present invention alleviates the impact from the rear wheel by vertically bending the curved portion of the leaf spring.

〔Example〕

Hereinafter, one embodiment of the present invention will be shown in FIGS. 1 to 3(a),
(b) will be explained in detail.

FIG. 1 is a side view of a motorcycle equipped with a rear wheel shock absorber for a motorcycle according to the present invention, FIG. 2 is a plan view showing a leaf spring of the rear wheel shock absorber for a motorcycle according to the present invention, and FIG. (a)
, (b) is an enlarged view showing the installation of the leaf spring,
Figure (a) is a plan view, and figure (b) is a side view. In these figures, 1 is the frame of the motorcycle, 2 is the engine mounted on this frame 1, 3 is the fuel tank, and 4 is the frame of the motorcycle.
5 is a seat, 5 is a muffler, and 6 is a front wheel suspended from the frame 1 via a front fork 7. 8 is a rear wheel, and this rear wheel 8 is connected to a rear arm 9 as a rear wheel support member.
It is supported by the frame 1 via
The chain 10 is configured to transmit power from the engine 2. This rear arm 9 has a pair of left and right arm portions 9a, and is connected to the frame 1 through a pivot shaft 11.
is supported by

Reference numeral 12 denotes a rear wheel shock absorber, and the rear wheel shock absorber 12 includes a leaf spring 13 disposed on the right side of the rear wheel 8 and a damper 14 that damps vibrations of the spring 13.

The leaf spring 13 is formed by molding glass fiber-reinforced plastic into an elongated plate shape along the fiber direction, and the molded shape is approximately an arc shape curved around the central portion in the longitudinal direction.

The leaf spring 13 is mounted on the bracket 15 with the curved portion positioned on the front side of the vehicle body and both ends positioned on the rear side of the vehicle body.
16 is fixed to the vehicle body.

The bracket 15 is attached to the right arm part 9 of the rear arm 9.
The bracket 16 is fixed on the right back stay 13 of the frame 1, and the bracket 16 is fixed on the
It is fixed at a location located just above the arm portion 9a. The leaf spring 13 has its lower end attached to the bracket 15 and its upper end attached to the bracket 16.
It is interposed between the right arm portion 9a and the right back stay 1a with each end thereof along the right arm portion 9a and the right back stay 1a, respectively. That is, the leaf spring 13 is attached to the vehicle body in a curved state with an axis substantially parallel to the vehicle width direction. The above mounting is the bracket 15゜16 is the leaf spring 1
a retaining plate 15a facing the main surface of No. 3 and facing the tip surface;
16a, and a pair of left and right claw pieces 15b, 1 integrally formed with the holding plates 15a, 16a and facing the side surfaces of the leaf spring 13.
6b. For reinstallation, the brackets 15 and 16 are fixed to the right arm portion 9a and the right back stay la so as to press and sandwich the leaf spring 13, respectively. In other words, both ends of the leaf spring 13 are clamped and held in the thickness direction by the brackets 15 and 16, respectively.

In addition, when this leaf spring 13 is molded, the radius of curvature of the curved portion is formed into a relatively large arc shape as shown by the dashed line in Figure 1, and when assembled into the vehicle body, the radius of curvature is changed to apply an initial load. It is bent and attached to make it smaller. To attach this leaf spring 13 to the vehicle body, first attach one end to the vehicle body as shown by the two-dot chain line in FIG. Attach the other end to the vehicle body as shown by the solid line in the figure. By attaching in this manner, the leaf spring 13 is attached with an initial load applied thereto.

The damper 14 includes a cylinder and a piston similar to those used in conventional motorcycles, and has a lower end connected to the rear arm 9 via a bump stop 14a made of rubber, and an upper end connected to the left and right sides of the frame 1. The cross member IC connects the seat rails Ib of the seat rails Ib to each other.

The damper mounting bracket 17 for connecting the damper 14 to the rear arm 9 is a bracket 17, and the damper mounting bracket 17 is provided protruding from the base of the rear arm 9.

18 is a carburetor of the engine 2, 19 is an air cleaner connected to this carburetor 18, and this air cleaner 19 is provided with a suction port 19a in a portion below the seat. 20 is a battery. This air cleaner 19
The battery 20 is installed at the rear of the engine 2 and just above the pivot shaft 11. The dimensions of the air cleaner 19 are set so that it can be installed in the space surrounded by the frame 1 at the rear of the engine along with the battery 20 over substantially the entire area.

In a motorcycle equipped with the rear wheel shock absorber 12 configured in this manner, the rear wheel 8 moves up and down as the leaf spring 13 changes the curvature of its curved portion and bends up and down. In other words, if the rear wheel 8 goes over a bump on the road surface while driving,
By bending the leaf spring 13, shocks and vibrations are alleviated.

Therefore, by employing this rear wheel shock absorbing device 9, the compression coil springs used in conventional motorcycles are no longer necessary, and the parts storage space behind the engine where the compression coil springs are located can be made larger.

Furthermore, when the leaf spring 13 is made of glass fiber reinforced plastic as shown in this embodiment, the spring constant can be set to be softer than that made of spring steel, and a leaf spring that does not rust can be obtained. I can do it. Moreover, since glass fiber reinforced plastic is lighter than spring steel, it is possible to reduce the weight of the vehicle body.

Furthermore, in this embodiment, the leaf spring 13 is interposed between the rear arm 9 and the backstay 1a, so that the leaf spring 13 is placed behind the engine within the width of the engine and protrudes to the side of the vehicle body. (Narukara, rear wheel shock absorber 9
can be installed compactly, and in addition, the unsprung weight can be reduced.

Although this embodiment shows an example in which the curved portion of the leaf spring 13 is positioned closer to the front of the vehicle body than both end portions, as shown in FIGS. 4 to 6, the direction of the leaf spring 13 may be changed to It is also possible to position the section at the rear of the vehicle.

4 to 6 are views showing other embodiments in which the orientation of the leaf spring is changed, and FIG. 4 is a side view showing a part of the motorcycle;
FIGS. 5(a) and 5(b) are enlarged views showing the mounting of the temporary spring on the lower side, with FIG. 5(a) being a plan view and FIG. 5(b) being a side view. FIG. 6 is an enlarged sectional view showing the upper mounting of the leaf spring. In these figures, the same or equivalent members as those explained in FIGS. 1 to 3 are given the same reference numerals and detailed explanations will be omitted. In this embodiment, the leaf spring 13 is mounted with its curved portion positioned rearward from both end portions, and the upper end of the damper 14 is pivotally supported by a cross member 1d that connects the left and right backstays 1a. The lower end of the leaf spring 13 is fixed to the right arm 9a of the rear arm 9 with a bracket 15, while the upper end is attached to the backstay 1a. It is fixed to the backstay 18 by a bracket 21.

As shown in FIG. 6, the bracket 21 consists of a pair of upper and lower holding plates 22 fixed to the backstay 1a and sandwiching the leaf spring 13, and a bolt 23 passing through both the holding plates 22 and the leaf spring 13. , are configured to hold the leaf spring 13 under pressure vertically. A cushion rubber 24 is interposed between the bracket 21 and the leaf spring 13. In this embodiment, the cushion rubber 24 is also interposed between the lower end of the leaf spring 13 and the vehicle body. That is, the upper and lower surfaces of the lower end of the leaf spring 13 are covered with a cushion rubber 24, and in this state, the leaf spring 13 is fixed to the rear arm 9 by a bracket 15. Therefore, the leaf spring 13 is elastically supported with respect to the vehicle body.

The plate spring 13 used in this embodiment is provided with a retaining protrusion 13a at the lower end of the leaf spring 13 by extending the tip of the lower end to both left and right sides from other parts.

The projection size of the retaining protrusion 13a is set so that it engages with the claw piece 15b of the bracket 15 during installation.

Even if the curved portion of the leaf spring 13 is positioned on the rear side in this way, the same effect as in the embodiment described above can be obtained.

Further, in the two embodiments described above, the present invention is applied to a motorcycle in which the engine 2 is positioned approximately in the middle between the front and rear wheels, but the present invention is not limited to such limitations. Instead, it can also be applied to a scooter as shown in FIGS. 7 and 8.

7 and 3 are views showing other embodiments in which the rear wheel shock absorber of the present invention is mounted on a scooter, FIG. 7 is a side view of the scooter, and FIG. 8 is a plan view showing the rear wheel shock absorber. It is. In these figures, the same or equivalent members as those explained in FIGS. 1 to 6 are given the same reference numerals and detailed explanations will be omitted. In these figures, 31 is a scooter, 32 is a frame of this scooter 31, and this frame 32 is connected to a front frame 33 and this front frame 3.
3, and a pair of left and right rear frames 34 branched from the rear end of the rear frame 34. The rear frame 34 is provided so as to be inclined rearward from a low-floor footrest 35, and a unit swing type engine 37 is swingably connected to this inclined portion via a link member 36.

The engine 37 includes an engine main body 37a having a sill oriented in a substantially vertical direction, and a power source extending to one side of the vehicle body (in this embodiment, to the left of the rear wheels 38) and transmitting engine power to the rear wheels 38. Transmission case 3 with built-in transmission mechanism
7b, and is configured so that the rear wheel 38 is supported by the transmission case 37b. This engine 37 is supported by the rear frame 34 by the rear wheel shock absorber 12 of the present invention.

The leaf spring 13 used in this embodiment has its upper part attached to the left rear frame 34 and its lower end attached to the transmission case 37 in the engine 37, which is just below the rear frame 34.
b, and the curved portions are positioned closer to the front of the vehicle body than both end portions. The upper and lower ends of this leaf spring 13 are formed by a pole (3) that passes through the leaf spring 13.
9. Rear frame 34 by 40. They are each fixed to the engine 37. Note that the upper end of the leaf spring 13 is fixed to the rear frame 34 via a bracket 41. This bracket 41 is fixed to the left rear frame 34 by welding or the like.

In this embodiment, the damper 14 is installed substantially horizontally in the lower part of the vehicle body in front of the engine 37.
7 and a portion of the frame 32 that corresponds to the footrest portion 35.

Further, this damper 14 is located approximately at the center in the vehicle width direction, and its front end is connected to a support plate 42 that is horizontally suspended between the left and right rear frames 34 at a footrest 35, and its rear end is connected to a support plate 42 that is suspended between the left and right rear frames 34. Connected to the front bottom.

43 is a carburetor of the engine 37, 44 is an air cleaner connected to this carburetor 43, and 45 is a muffler. The air cleaner 44 is installed above the transmission case 37b of the engine 37.

As described above, in the scooter equipped with the rear wheel shock absorbing device 12 according to the present invention, the rear wheel 38 moves up and down as the leaf spring 13 bends up and down by changing the curvature of the curved portion.

That is, by bending the leaf spring 13, the impact and vibration from the rear wheel 38 is alleviated.

Therefore, by employing this rear wheel shock absorbing device 12, the compression coil spring used in conventional scooters becomes unnecessary, and the space above the engine where the compression coil spring is disposed can be expanded.

In the embodiments shown in FIGS. 7 and 8, the leaf spring 13 is mounted with the curved portion positioned forward of both the upper and lower ends, but the orientation of the leaf spring 13 is such that the curved part is positioned rearward of both the upper and lower ends. It is also possible to reverse the direction of this embodiment so that the position is oriented to . Furthermore, the leaf spring 13 can also be formed into a substantially annular shape instead of being formed into a bent plate shape.

〔Effect of the invention〕

The rear wheel shock absorber for a motorcycle according to the present invention includes a leaf spring interposed between a rear wheel support member and a body frame positioned above the rear wheel support member, and a leaf spring that damps vibrations of the leaf spring. Since the leaf spring is curved in the longitudinal direction of the vehicle body, the impact from the rear wheel is alleviated by the vertical deflection of the curved portion of the leaf spring. . For this reason, when this rear wheel shock absorber is adopted, a compression coil spring is no longer required, so motorcycles can have a large parts storage space behind the engine, and large parts such as air cleaners can be placed in this parts storage space. It can be installed without being restricted by location. Furthermore, in scooters as well, it becomes possible to have a wider space for parts to be mounted above the engine, so parts mounted in this area have greater flexibility in placement, and the capacity of parts such as air cleaners can be increased.

[Brief explanation of the drawing]

FIG. 1 is a side view of a motorcycle equipped with a rear wheel shock absorber for a motorcycle according to the present invention, FIG. 2 is a plan view showing a leaf spring of the rear wheel shock absorber for a motorcycle according to the present invention, and FIG. (a)
, (b) is an enlarged view showing the installation of the leaf spring,
Figure (a) is a plan view, and figure (b) is a side view. Fourth
6 to 6 are views showing other embodiments in which the orientation of the leaf spring is changed, FIG. 4 is a side view showing a part of the motorcycle, and FIG. 5 is a side view showing a part of the motorcycle.
Figures (a) and (b) are enlarged views showing the mounting of the leaf spring on the lower side, with figure (a) being a plan view and figure (b) being a side view. FIG. 6 is an enlarged sectional view showing the upper mounting of the leaf spring. 7 and 8 are views showing other embodiments in which the rear wheel shock absorber of the present invention is mounted on a scooter, FIG. 7 is a side view of the scooter, and FIG. 8 is a plan view showing the rear wheel shock absorber. It is. 1.32...Frame, 9...Rear arm, 1
2... Rear wheel shock absorber, 13... Leaf spring, 14...
...Damper 19.44...Air cleaner,
36...Link member, 37...Unit swing type engine. Figure 2 District 3

Claims (1)

[Claims] In a motorcycle in which a rear wheel is swingably provided on a body frame via a rear wheel support member, the rear wheel shock absorber of the motorcycle is positioned above the rear wheel support member and the rear wheel support member. The vehicle comprises a leaf spring interposed between the vehicle body frame and a damper that damps vibrations of the leaf spring, and is characterized in that the leaf spring is curved in the longitudinal direction of the vehicle body. A rear wheel shock absorber for motorcycles.