JP2003081166A - Motorcycle body frame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motorcycle body frame in which the longitudinal rigidity and the transverse rigidity can be increased while the torsional rigidity is less affected. SOLUTION: In the motorcycle body frame 1 having a pair of right and left frames, a member to connect front ends and rear ends of the pair of right and left frames, and a middle cross member 21 to connect middle parts of the pair of right and left frames, the middle cross member 21 is formed of a flat metal plate having a flat surface in the width direction and in the longitudinal direction of the motorcycle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body frame of a motorcycle.

[0002]

2. Description of the Related Art As a body frame of a motorcycle, for example, there are a pair of left and right seat rails which are located above the rear wheels and support a seat, and the rear end portions of the pair of left and right seat rails are connected by a cross member. , In addition, there is a cross member that connects the middle part.

[0003]

By the way, in such a structure of the vehicle body frame, the front side of the pair of left and right seat rails is fixed to the main frame and the rear arm bracket, but the middle cross member is made of pipe material. The cross member in the middle part is a structure that simply bridges the left and right, and is effective for the vertical rigidity of the vehicle in the vertical direction, but is not effective for the lateral rigidity in the vehicle width direction and the front-rear direction. there were.

For this reason, it is conceivable to make the pipe material large in diameter, but the torsional rigidity becomes higher accordingly, and for example, when a heavy load is loaded, the swing of the load is transmitted to the vehicle body via the seat rail, Affects driving stability. Further, there is a problem that the weight is increased due to the increase in the diameter of the pipe material.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a vehicle body frame of a motorcycle capable of increasing the longitudinal rigidity and the lateral rigidity by reducing the influence on the torsional rigidity. .

[0006]

In order to solve the above-mentioned problems and to achieve the object, the present invention has the following constitution.

According to the invention described in claim 1, "a pair of left and right frames, a member for connecting the front end and the rear end of the pair of left and right frames, respectively, and an intermediate cross connecting the intermediate portions of the pair of left and right frames. In a vehicle body frame of a motorcycle having a member, the intermediate cross member,
A vehicle body frame for a motorcycle, comprising a flat metal plate having a flat surface in a vehicle width direction and a front and rear direction. ].

According to the invention described in claim 1, when a vertical load is applied to the vicinity of the rear ends of the pair of left and right frames without the intermediate cross member, a member for connecting the rear ends is formed near the rear ends. Since the front end has a member that connects the front ends, a pair of left and right frames are deformed in the middle part so that the distance between them is changed. Also, by adding an intermediate cross member, the deformation can be prevented, the vertical rigidity can be increased while reducing the influence on the torsional rigidity, and the lateral rigidity can also be effectively increased, and it is lightweight.

The invention according to claim 2 is that "the pair of left and right frames are a pair of left and right seat rails which are located above the rear wheels and support a seat. Motorcycle body frame. ].

According to the second aspect of the present invention, the pair of left and right frames are the pair of left and right seat rails which are located above the rear wheels and support the seat. For example, when a heavy luggage is loaded. Even if luggage is shaken, the pair of left and right seat rails are twisted and the shake is difficult to be transmitted to the vehicle body, so there is little influence on running stability, vertical rigidity and lateral rigidity can be effectively increased, and lightweight Is.

According to a third aspect of the present invention, "the intermediate cross member is disposed above the rear wheel, and the rear fender that covers the rear wheel runs off on the side close to the apex of the rear wheel of the intermediate cross member. The vehicle body frame of the motorcycle according to claim 2, wherein a notch portion is formed. ].

According to the third aspect of the present invention, the intermediate cross member is provided without impairing the longitudinal rigidity and the lateral rigidity.
It can be placed in a limited space above the rear wheel.

According to a fourth aspect of the present invention, "the intermediate cross member is formed with a lightening opening while leaving a diagonal shape in the vehicle width direction.
The body frame of the motorcycle according to any one of claims 1 to 3. ].

According to the invention described in claim 4, the intermediate cross member is provided without impairing the longitudinal rigidity and the lateral rigidity.
The weight can be reduced.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a vehicle body frame of a motorcycle according to the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a side view of the motorcycle, FIG. 2 is a plan view of the motorcycle, and FIG. 3 is a side view of the front side portion of the vehicle body frame.
4 is a side view of the front side portion of the vehicle body frame, FIG. 5 is a plan view of the front side portion of the vehicle body frame, and FIG. 6 is a side view showing a seat mounting state.

A front fork 4 on which a front wheel 3 is suspended is rotatably supported on a front side portion of a main frame 2 of a vehicle body frame 1 of a motorcycle, and can be steered by a bar handle 5. In the central part of the main frame 2,
A fuel injection type 4-cycle engine 6 is mounted.
A rear arm bracket 7 is connected to the rear side of the main frame 2, the front side of a rear arm 8 is pivotally supported by the rear arm bracket 7, and the rear wheel 9 is supported on the rear side of the rear arm 8.

A movable rear fender 10 is attached to the rear arm 8 to cover the front upper side of the rear wheel 9.
The pair of exhaust pipes 11 connected to the front side of the engine 6 pass below the engine 6 and are located on both sides of the rear wheel 9.

A seat rail 12 is connected to the rear arm bracket 7, and the seat rail 12 extends to a position above the rear wheel 9. In the seat rail 12,
A seat 13 is attached, a rear cowl 14 is attached to the rear side of the seat rail 12, and a fixed rear fender 15 that covers the rear upper side of the rear wheel 9 is attached.

The front side of the seat 13 is attached to a fuel tank 16 attached to the main frame 2.
Front cowl 17 from the front side of the main frame 2 to the left and right
Is covered with.

The main frame 2 is, as shown in FIG.
It is composed of a front side portion 2a and a rear side portion 2b formed by casting. The front side portion 2a includes a head pipe portion 2a1 and a frame portion 2a2 extending rearward from the head pipe portion 2a1 to the left and right. The rear side portion 2b is composed of a pair of left and right frame portions 2b1 welded to a frame portion 2a2 extending to the left and right of the front side portion 2a. The frame portion 2b1 and the frame portion 2
A bracket 20 is welded between a2 and a2, and the engine 6 is supported by the bracket 20.

A rear arm bracket 7 is welded to the frame portion 2b1 of the main frame 2, and a pair of left and right seat rails 12 are attached to the upper portions 7a and 7b of the rear arm bracket 7, respectively.

The pair of left and right seat rails 12 comprises a front rail portion 12a formed by casting and a rear rail portion 12b formed by extruding an aluminum material, and the front rail portion 12a and the rear rail portion 12b are connected by welding. Has been done.

The front rail portions 12a of the pair of left and right seat rails 12 are connected by an intermediate cross member 21, and the rear rail portions 12b are connected by a rear end cross member 22,
Further, a seat mounting bracket 23 is spanned.
The rear end cross member 22 is made of a pipe material.

The intermediate cross member 21 is formed of a metal flat plate having a flat surface in the vehicle width direction and the front-rear direction, and both end portions 21a in the vehicle width direction are the mounting portions 12a1 of the front rail portion 12a.
Is welded to. The intermediate cross member 21 is left with the diagonal shapes X and Y in the vehicle width direction, and the lightening opening 21 is formed.
a2 to 21a5 are formed.

The front rail portion 12a has a mounting portion 12a.
2, 12a3 are formed, and the mounting portions 12a2, 12a
3 is applied to the upper portions 7a and 7b of the rear arm bracket 7 and attached by tightening means 30 such as bolts and nuts.

In the seat 13, the locking claws 13a1 formed on the bottom plate 13a are locked to the locking portions 16a of the fuel tank 16, and the rubber dampers 31 and 32 attached to the bottom plate 13a.
Can be supported by the support portion 12a4 of the front rail portion 12a and the intermediate cross member 21, and the lock lever 33 fixed to the bottom plate 13a is inserted into the lock hole 23a of the seat mounting bracket 23 and locked by a lock device (not shown).

The rubber damper 31 of the bottom plate 13a of this embodiment has a gap with the supporting portion 12a4 of the front rail portion 12a, but the rubber damper 31 is supported so as to abut the intermediate cross member 21 to prevent impacts during traveling. When a large load is applied to the seat 13, the rubber damper 31 comes into contact with and supports the support portion 12a4 of the front rail portion 12a.

In this embodiment, the intermediate cross member 21 is made of a metal flat plate having a flat surface in the vehicle width direction and the front-rear direction, and has diagonal shapes X and Y in the vehicle width direction. When a vertical load is applied near the rear end of the seat rail without the intermediate cross member 21, the rear cross member 22 is located near the rear end and the main frame 2 is located at the front end. Rail 1
2 is accompanied by deformation such that the distance between them changes. Against such deformation, even if it is a metal flat plate, by adding the intermediate cross member 21, the deformation can be prevented, the vertical rigidity can be increased, and the lateral rigidity can be effectively increased, and the weight can be reduced. is there.

Further, for example, even if a heavy load is loaded on the rear portion of the seat 13, the pair of left and right seat rails 12 are twisted and the shake is hard to be transmitted to the vehicle body, so that the running stability is improved. Is less affected by.

The intermediate cross member 21 has a rear wheel 9
Of the rear cross-section of the rear fender 15 disposed on the front side of the rear side of the intermediate cross member 21 near the apex of the rear wheel, that is, on the rear side of the intermediate cross member 21.
a10 is formed. In this way, the intermediate cross member 21 can be attached to the rear wheel 9 without impairing the longitudinal rigidity and the lateral rigidity.
Can be placed in a limited space above.

In this embodiment, the intermediate cross member 21 is arranged on the front side above the rear wheel 9.
The rear notch portion 21a10 of the rear fender 15 that covers the rear wheel 9 is formed on the front side of the intermediate cross member 21 in this case.

In this embodiment, the intermediate cross member 21 of the pair of left and right seat rails 12 is made of a metal flat plate having a flat surface in the vehicle width direction and the front-rear direction. However, the present invention is not limited to this, and the main frame is made up. The same can be applied to a case where a pair of left and right frames are connected by an intermediate cross member.

[0034]

As described above, according to the first aspect of the present invention, the intermediate cross member is made of a metal flat plate having a flat surface in the vehicle width direction and the front-rear direction, thereby reducing the influence on the torsional rigidity. The vertical rigidity and the lateral rigidity can be effectively increased and the weight is light.

According to the second aspect of the present invention, the pair of left and right frames are a pair of left and right seat rails which are positioned above the rear wheels and support the seat. For example, when a heavy load is loaded, the load fluctuates. Even if something happens, since the pair of left and right seat rails 12 are twisted and the vibration is hard to be transmitted to the vehicle body,
It has little influence on running stability, can effectively increase vertical rigidity and lateral rigidity, and is lightweight.

According to the third aspect of the invention, the intermediate cross member can be arranged in the limited space above the rear wheel without impairing the longitudinal rigidity and the lateral rigidity.

According to the invention described in claim 4, the intermediate cross member can be reduced in weight without impairing the longitudinal rigidity and the lateral rigidity.

[Brief description of drawings]

FIG. 1 is a side view of a motorcycle.

FIG. 2 is a plan view of the motorcycle.

FIG. 3 is a side view of a front side portion of a vehicle body frame.

FIG. 4 is a side view of a front side portion of the vehicle body frame.

FIG. 5 is a plan view of a front side portion of the vehicle body frame.

FIG. 6 is a side view showing a mounted state of the seat.

[Explanation of symbols]

1 body frame 2 mainframe 7 Rear arm bracket 9 rear wheels 12 seat rails 13 sheets 15 Fixed rear fender 21 Middle Cross Member 22 Rear cross member 21a2 to 21a5 lightening opening 21a10 escape notch X, Y diagonal shape in the vehicle width direction

Claims (4)

[Claims] 1. A vehicle body of a motorcycle having a pair of left and right frames, a member for connecting front and rear ends of the pair of left and right frames, and an intermediate cross member for connecting an intermediate portion of the pair of left and right frames. In the frame, the vehicle body frame of the motorcycle, wherein the intermediate cross member is made of a metal flat plate having a flat surface in a vehicle width direction and a front-rear direction. 2. The vehicle body frame for a motorcycle according to claim 1, wherein the pair of left and right frames are a pair of left and right seat rails that are located above the rear wheels and support the seat. 3. The intermediate cross member is disposed above the rear wheel, and an escape cutout portion of a rear fender that covers the rear wheel is formed on a side near a rear wheel apex of the intermediate cross member. The vehicle body frame of the motorcycle according to claim 2. 4. The lightening opening is formed in the intermediate cross member, leaving a diagonal line shape in the vehicle width direction, according to any one of claims 1 to 3. Body frame of the motorcycle described.