JPH04292290A - Wheel suspension system for motorcycle - Google Patents

Abstract

PURPOSE:To expand a suspension space for equipment such as an exhaust mufller, an air cleaner case or the like as well as to secure such a wheel suspension system as having functions including concentrating the mass, low ering the position of gravity center and guarding the equipment. CONSTITUTION:In a rear fork 2, an intermediate part of its arm 2a forms an inverted arch bent more downward than a straight line connecting each of both front and rear ends 1d and 2d, constituting a cross-member 2b in a low position of the rear fork 2, through which it prevents any interference with body functioning parts at the upper part of this cross-member 2b or arm 2a, thus the degree of freedom for low ering the position of gravity center of body and the setup of these functioning parts is improved.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wheel suspension system for a motorcycle, and more particularly to a wheel suspension system that contributes to expanding the space for mounting equipment.

0002

[Prior art] Motorcycles were developed in 1986-13386.
As shown in the figure, the engine, auxiliary equipment, and other components are mounted on the vehicle body frame, and one end of the vehicle frame is swingably connected to the vehicle body frame via a shock absorber below the seat frame at the rear of the vehicle body frame. , and a wheel suspension device comprising an arm member rotatably supporting the rear wheel at the other end.

0003

[Problem to be Solved by the Invention] However, the shock absorbing device for a wheel suspension system has to be constructed in a large size due to the magnitude of the acting force applied and restrictions on its shock absorbing and supporting characteristics. If you try to lower the center of gravity,
When increasing the size of auxiliary equipment such as air cleaners and storage compartments,
Due to the space occupied by the shock absorber, the installation positions of vehicle body auxiliary equipment and equipment are restricted, and there is a problem in that flexibility in the arrangement of equipment on the vehicle body cannot be obtained.

0004

[Means for Solving the Problems] In order to solve the above problems, the arm member of the wheel suspension system has an arch shape such that the intermediate portion in the front and rear direction protrudes downward in side view from the line connecting the axles of the front and rear wheels. A shock absorber connecting member was provided at the bent portion.

[0005] Furthermore, the arm member of the wheel suspension system has an inverted arch-shaped recess in a side view in which the intermediate portion thereof is bent downward from a straight line connecting both the front and rear ends of the arm member. The wheel suspension system was configured to prevent interference with functional parts.

[0006] The vehicle body-side functional parts are used as a wheel-driving wrap-around power transmission section, an engine exhaust muffler, or a storage container to form a wheel suspension system.

[0007]

[Operation] Since the arm member is provided with a shock absorber at the inverted arch-shaped bent portion below the straight line connecting the axles of the front and rear wheels, the space above the arm member is expanded and the center of gravity of the vehicle is lowered.

Furthermore, since the arm member is formed in an inverted arch shape in which the intermediate portion of the arm on at least one side is bent downward from the straight line connecting both the front and rear ends, it is possible to prevent interference when the arm member swings. The upper part acts as a guard from the outside, lowering the center of gravity of the vehicle body and expanding the space for the above-mentioned functional parts.

[0009] By using the vehicle body-side functional parts as a wheel-driving wrap-around power transmission unit, an engine exhaust muffler, or a storage container, it is possible to prevent interference when the arm member swings, and to prevent interference from outside when the arm member swings. This serves as a guard, lowering the center of gravity of the vehicle and expanding the space for installing equipment.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side view of a wheel suspension system according to a first embodiment of the present invention, FIG. 2 is a detailed view of the main part of FIG. 1, FIG. 3 is a plan view of the first embodiment, and FIG. IV-IV line sectional view, Figure 5
is a sectional view taken along the line V-V in FIG. 1.

[0012] The vehicle body frame 1 is provided with a rear fork 2 connected to the rear so as to be able to swing up and down, and this rear fork 2
An arm member is constructed by connecting arms 2a, 2a that support the rear wheel 3 from both sides with a cross member 2b in the middle thereof.

The arm 2a has an inverted arch shape in which the intermediate portion thereof is bent downward from a straight line connecting both the front and rear ends, and the cross member 2b is configured at a lower position of the rear fork 2.
A shock absorber 4 is provided along the lower side 1b of the vehicle body frame to be interposed between the cross member 2b and the cross frame 1a at the front of the lower side of the vehicle body frame 1. A is front wheel center axis B
and the rear wheel center axis C, and the bent portion D of the arm 2a is located below the straight line A when one person is on board. Then, a shock absorber connecting member is provided at the bent portion D.

A main link 4b is attached to one end 4a of the shock absorber 4, and this main link 4b is attached to a mounting portion 1c of the vehicle body frame 1 above it. This main link 4
A sub-link 4c is connected between the intermediate portion 4d of the cross member 2b and the mounting portion 2c at the center of the lower surface of the cross member 2b to form a progressive link mechanism.

Via the link mechanism, the shock absorber 4 cushions and supports the rear fork 2 in a posture along the lower side 1b of the vehicle body frame 1 below the engine 1e mounted forward in the center of the vehicle body frame 1. .

[0016] The arms 2a, 2a of the rear fork 2 are able to maintain their position on the cross member 2 even when the rear fork 2 is raised.
It is formed into an inverted arch shape bent within a range that does not interfere with the lower side of the rear wheel drive chain 3a.

Large equipment such as an air cleaner case 1f above the engine 1e and a fuel tank 1g above the body frame 1 are mounted at their respective positions, and a rider seat 5 and rear A large storage part 5a for a helmet etc. is provided between the fork 2 and the fork 2. This storage portion 5a is arranged from below the seat 5 to the rear and below the fuel tank 1g.

Furthermore, the chain 3 of the rear fork 2 in FIG.
A muffler 7 is arranged on the opposite side from a, and this muffler 7
When the rear fork 2 is raised, it tilts forward and downward so as to be substantially parallel to the arm 2a, and due to the inverted arch shape of the arm 2a, the front end of the muffler 7 is disposed at a lower position. In addition, 1d is a connection pivot of the rear fork 2, 2d is a rear wheel support part of the rear fork 2, and the vehicle body frame 1
A front wheel suspension unit 6 is connected to the front head pipe 1h.

The operation of the wheel suspension system for a motorcycle according to the present invention having the above configuration will be explained.

[0020] The rear fork 2 moves according to the road surface conditions.
It swings up and down around the connection pivot 1d. At this time, the shock absorber 4 is connected to the lower side of the vehicle body frame 1 under the engine 1 e mounted forward in the center of the vehicle body frame 1 via the progressive link mechanisms 4 b and 4 c configured at a lower position of the rear fork 2 . Rear fork 2 in a posture along line 1b
Buffer and support.

Therefore, the shock absorbing mechanism of the wheel suspension system is constructed below the rear fork 2 and the vehicle body frame 1, and the area above the rear fork 2 at the rear of the vehicle body frame 1 is used as a large storage area 5a for helmets, etc. be able to.

FIG. 6 is a side view of a second embodiment of the present invention;
FIG. 7 is a sectional view taken along the line VII-VII in FIG. 6.

In off-road vehicles, the vertical stroke of the wheels is very large, so the muffler 17 is provided at a high position next to the rear wheel 13 and near the rider seat 15. This muffler 17 is connected to an exhaust pipe 17a of a four-cycle engine 11e mounted on the vehicle body frame 11.

The rear fork 12, which is swingably connected to the vehicle body frame 11, has an inverted arch shape in which the middle portion of the arm 12a on the side where the muffler 17 is attached is bent downward from a straight line connecting its front and rear ends. The muffler 17 defines its lower side shape following the downwardly bent inverted arch shape of the arm 12a at the upper limit position U12a of the rear fork 12. A
is a straight line connecting the front wheel center axis B and the rear wheel center axis C, and the bent portion D of the arm 12a is located below the straight line A when one person is on board.

Arm 12e on the other side of rear fork 12
forms a general straight line. A main link 14b that connects the shock absorber 14 is attached to a cross member 12b that connects these, and is connected to a sub link 14c that is attached to the vehicle body frame 11 below to form a progressive link mechanism. , buffer 14
is arranged at the rear of the vehicle body frame 1. A is front wheel center axis B
and the rear wheel center axis C, and the bent portion D of the arm 12a is located below the straight line A when one person is on board.

With the above configuration, the rear wheel 13 is buffer-suspended via the progressive link mechanism and the shock absorber 14. When the rear wheel 13 reaches the upper limit position depending on the road surface condition, the intermediate portion of the arm 12a of the rear fork 12 avoids the lower side of the muffler 17, which is a functional component on the vehicle body side.

As described above, the wheel suspension system for a motorcycle according to the present invention has an expanded upper usage area, and the muffler 1
7 has its lower side curved downward to follow the shape of a reverse arch, thereby increasing the length in the front-rear direction of the muffler 17 of the 4-stroke engine 11e, which requires a larger volume than the exhaust pipe 17a. It is possible to shorten the time.

FIG. 8 is a side view of a main part of a third embodiment of the present invention.

Rear fork 2 at the rear of the vehicle body frame 21
A large storage container such as an air cleaner case 21f is disposed above the air cleaner case 21f. The rear fork 22 is connected to the vehicle body frame 21 so as to be swingable in the vertical direction by a connection pivot provided on the vehicle body frame 21. The left and right arms 22a, 22a of the rear fork 22 are formed in an inverted arch shape bent downward, and have a large degree of deflection, especially toward the connection pivot 21d. The shape of the lower side of the air cleaner case 21f is determined by following the curved portion of the arm 22a in an inverted arch shape at the upper limit position of the rear fork 22.

With this configuration, when the rear fork 22 swings and reaches its upper limit position, both arms 22a, 22
The inverted arch-shaped bent portion a avoids the lower side of the air cleaner case 21f, which is a functional component on the vehicle body side. Therefore, the upper usable area of the wheel suspension system for a motorcycle according to the present invention is expanded, and the air cleaner case 21f expanded downward can be mounted thereon. In addition, if a vehicle body-side functional component is similarly applied to a chain-side arm as a chain-wound power transmission member, the lower part of the arm functions as a guard for the chain.

[0031]

[Effects of the Invention] As explained above, according to the first invention, since the shock absorber connecting portion is provided at a bent low position of the arm member, there is freedom in the arrangement space for vehicle body auxiliary equipment and equipment above the arm. In addition, it is possible to lower the center of gravity of the vehicle.

According to the second invention, by forming the arm member into an inverted arch shape bent downward, it is possible to increase the size of the functional parts disposed above the arm member and to lower the center of gravity of the vehicle body.

According to the third invention, the chain-wound power transmission member above the arm member can be guarded, and according to the fourth invention, the height dimension of the muffler above the arm member can be guarded. It is possible to configure a muffler that can be made large, has a large capacity, and has little protrusion to the side or rear of the vehicle body.Furthermore, according to the fifth invention, a large equipment installation space is provided in the front part of the arm member. can be taken,
It is possible to make the vehicle more compact and improve functionality.

[Brief explanation of drawings]

FIG. 1 is a side view of a wheel suspension system according to a first embodiment of the present invention.

FIG. 2 is a detailed view of the main part of FIG. 1;

FIG. 3 is a plan view of the first embodiment.

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 1;

FIG. 5 is a sectional view taken along line V-V in FIG. 1;

FIG. 6 is a side view of a second embodiment of the present invention.

7 is a sectional view taken along the line VII-VII in FIG. 6. FIG.

FIG. 8 is a side view of main parts of a third embodiment of the present invention.

[Explanation of symbols]

1, 11...Vehicle frame 1a... Lower front part of the frame 1b...Bottom side of frame 2a, 12a, 22a...arm 2, 12, 22...Rear fork 3...Rear wheel 3a...Chain 4...Buffer 5a...Storage section 7,17...Muffler 21f...Air cleaner case

Claims (5)

[Claims] 1. A wheel suspension system for a motorcycle comprising an arm member that is vertically swingably connected to a vehicle body frame at one end and rotatably supports a wheel at the other end,
The arm member is bent into an arch shape so that the intermediate portion in the front and rear direction projects downward in side view from the line connecting the axles of the front and rear wheels, and a shock absorber connecting member is provided at the bent portion. Motorcycle wheel suspension system. 2. A wheel suspension system for a motorcycle comprising an arm member that is vertically swingably connected to a vehicle body frame at one end and rotatably supports a wheel at the other end,
forming an inverted arch-shaped recess in side view in which the intermediate portion of the arm member is bent downward from a straight line connecting both front and rear ends of the arm member;
A wheel suspension system for a motorcycle, characterized in that the recessed space prevents interference with functional parts on the vehicle body when the arm member swings. 3. The wheel suspension system for a motorcycle according to claim 2, wherein the vehicle body-side functional component is a wrap-around power transmission section for driving a rear wheel. 4. The wheel suspension system for a motorcycle according to claim 2, wherein the functional component on the vehicle body side is an exhaust muffler of an engine. 5. The wheel suspension system for a motorcycle according to claim 2, wherein the vehicle body-side functional component is a storage container.