JP2001213377A - Frame for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a frame for a motorcycle easily changeable in the setting of frame rigidity. SOLUTION: A main frame comprises a front body 1 and a rear body 2 made of aluminum. The front body 1 comprises a first frame 21 formed of a pipe member, and a second frame 22 formed of a plate. The second frame 22 is detachably attached to a boss part 23 provided at the first frame 21, through a bolt 24, and rigidity can be changed by changing the second frame 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art The frame of a general motorcycle is made of steel or aluminum pipes. For the purpose of reducing the weight, a frame made of resin or fiber reinforced resin is used. Japanese Patent Application Laid-Open No. 209672/1992 and Japanese Patent Application Laid-Open No. 4-71978 / 1992.

[0003] In particular, in Japanese Patent Application Laid-Open No. 58-209672, the main part (upper tube) of a motorcycle,
The down tube, seat tube, seat stay and tail are integrally formed from a fiber reinforced resin profile (molded material), and a reinforcing pipe material is provided inside the integrally molded resin frame. I have. It has been proposed that the pipe material is not limited to fiber reinforced resin but may be made of metal.

[0004]

If the rigidity of the frame of the motorcycle is too high, the ability to follow the road surface is deteriorated. Conversely, if the rigidity of the frame is low (soft), the frame tends to bend due to the driving force. Come out.

In motorcycles for racing and motorcycles for testing, it is convenient if the rigidity of the frame can be easily changed during practice driving or test driving in order to know the optimal frame rigidity. It is difficult to change the frame itself for both the pipe frame and the fiber reinforced resin frame.

[0006]

Means for Solving the Problems To solve the above problems, a motorcycle frame according to the present invention comprises a first frame made of a pipe material and a second frame made of a plate material,
The first frame forms a skeleton, and the second frame is detachably attached to the first frame via fixing means such as bolts.

[0007] With this configuration, a plurality of types of second frames having different rigidities are prepared, and by exchanging the second frames, the rigidity of the frames can be easily changed. Can be set in a short time.

[0008]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view of a motorcycle to which a frame according to the present invention is applied. A main frame of the motorcycle includes a front body 1 and a rear body 2 attached to a rear end of the front body 1. These front body 1 and rear body 2 The engine 3 is suspended and supported.

A head tube 4 is attached to a front end of the front body 1, and an upper end of a front fork 5 is supported by the head tube 4.
Is connected to the shaft of the front wheel 6.

A cowling 7 is arranged in front of the front fork 5. This cowling 7 is a radiator 8
It extends to the rear lower side to cover. Also cowling 7
An intake port 9 is formed on the front surface of the fuel tank 11, and an intake duct 10 extends from the intake port 9 to the intake box 12 through the front of the fuel tank 11.

A front end portion of a seat rail 13 is mounted on the upper portion of the rear body 2, and a seat 14 is provided on the seat rail 13. A pivot shaft 15 passes through an intermediate portion of the rear body 2, and a pivot shaft 15 extends through the middle portion. A front end of a swing arm 16 is swingably supported by 15, and a rear end of the swing arm 16 is connected to a shaft of a rear wheel 17.

A link member 18 is provided between the lower end of the rear body 2 and the swing arm 16, and the lower end of a shock absorber 19 having an upper end attached to the main frame 1 is connected to the link member 18. In addition, a buffering action is exerted with the swing of the swing arm 16.

Next, the configuration of the main frame will be described with reference to FIGS. Here, FIG. 2 is a perspective view of the main frame, FIG. 3 is a cross-sectional view taken along line AA of FIG. 2, and FIG. 4 is a view in which a first frame and a second frame constituting the front body 1 of the main frame are separated. .

As described above, the main frame comprises the front body 1 and the rear body 2 made of aluminum, and the front body 1 further comprises the first frame 21 made of pipe material.
And a second frame 22 made of a plate material. Therefore, in the case of the present embodiment, the main frame has a three-piece structure. The second frame 22 is mounted on the left and right sides of the first frame 21, respectively, but the right second frame is not shown in FIGS. 2 and 4.

The first frame 21 includes a head tube 4
An upper pipe 21a extending obliquely downward from the upper end of the upper pipe,
A lower pipe 21b extending obliquely rearward and downward from a lower end of the head tube 4 and a connecting pipe 21c connecting a rear end of the upper pipe 21a and a lower end of the lower pipe 21b are provided on the left and right sides, respectively.
b and the connecting pipe 21c determine the outer shape of the front body 1.

The first frame 21 also includes an auxiliary pipe 21d and a cross pipe 21e disposed between the upper pipe 21a, the lower pipe 21b, and the connecting pipe 21c. The pipes constituting the first frame 21 are assumed to be made of titanium, stainless steel, aluminum, or other general materials used for motorcycle frames.

Further, a plurality of boss portions 23 are provided at predetermined intervals on the outer surface of each pipe constituting the first frame 21 as means for fixing the second frame 22 made of a plate material. In the present embodiment, the boss portions 23 are provided at equal intervals by selecting a portion having a large bend as a portion that affects the rigidity of the frame and a portion near the connecting portion of the pipes. Is also good. As a fixing means, a female screw for fastening with a bolt 24 described later is provided in the boss portion 23. The means for fixing is not limited to the fastening means using bolts, but may be any means that can detachably and securely fix the second frame to the first frame.

Incidentally, depending on the running conditions, all the bosses 23
It is not necessary to fix the second frame 22 using the bolts 24, and it is also possible to fix the second frame 22 only at necessary places. Thus, in addition to changing the entire frame rigidity by replacing the second frame, it is possible to make a subtle change in the overall frame rigidity even when the same second frame is used, which is more optimal. A high frame rigidity can be obtained.

On the other hand, the second frame 22 is made of a fiber reinforced resin or an aluminum plate. As the fiber reinforced resin, an epoxy resin, a polyester resin or a phenol resin is used as a matrix, and carbon fibers, polyamide fibers, glass fibers, silicon carbide fibers, boron fibers, alumina fibers, and the like are suitable as fibers to be added thereto.

When a fiber reinforced resin is used as the second frame 22, the directionality of the fibers is controlled so that the rigidity of the frame can be given a directivity, and it is easy to achieve both the rigidity of the frame and the weight reduction. . When a fiber reinforced resin is used, an arbitrary rigidity can be set for each part by partially changing the amount of the fiber reinforced resin laminated.

In the embodiment, the first frame 21
The rigidity ratio between the first frame 2 and the second frame 22 is set to about 50:50.
The rigidity of the entire frame can be easily changed without changing the rigidity of the first frame, and the optimal frame setting can be performed in a short time.

In the embodiment, the second frame 2
2 is left and right one by one.
Only a part of the frame 22 may be replaced. As a result, fine frame rigidity can be set, and more optimal frame rigidity can be obtained.

Further, an opening may be formed in a part of the plate material constituting the second frame 22, and this opening may be used as an intake port.
As a result, new air introduced from the front of the vehicle body is disposed substantially at the center of the vehicle body without affecting the rigidity of the first frame 21, that is, without affecting about 50% of the vehicle body rigidity. It can be guided to a vaporizer.
Also, the second frame 22 may be configured to also serve as a side cowl. As a result, the size of the vehicle body can be reduced, the air resistance value can be reduced, and the side cowl can be eliminated because the second frame also serves as the side cowl, so that a low-priced vehicle body can be obtained.

FIG. 5 is a view showing an example in which the frame according to the present invention is applied to a swing arm. FIG. 6 is a sectional view taken along the line BB of FIG. However, as shown in this figure, the swing arm 16 is connected to a first frame 31 made of a pipe material and a second frame 31 made of a plate material.
The first frame 31 and the second frame 32 are detachable using a boss 33 and bolts 34.

[0025]

According to the present invention as described above,
The motorcycle frame is composed of a first frame made of a pipe material and a second frame made of a plate material. The first frame constitutes a frame, and the second frame is attached to and detached from the first frame via fixing means such as bolts. Since it is possible, by changing the second frame, the setting of the frame rigidity can be easily changed, the optimum setting can be performed in a short time, and the frame for a motorcycle for racing or test driving. As an excellent effect.

In particular, if the second frame is made of a fiber reinforced resin such as a carbon fiber reinforced resin, the rigidity can be arbitrarily changed by partially changing the lamination amount of the fiber reinforced resin. By setting the directionality to a specific direction, it is also possible to provide rigidity with directivity.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle to which a frame according to the present invention is applied.

FIG. 2 is a perspective view of a motorcycle frame according to the present invention.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a view in which a first frame and a second frame constituting the motorcycle frame are separated.

FIG. 5 is a diagram showing an example in which a frame according to the present invention is applied to a swing arm.

FIG. 6 is a sectional view taken along line BB of FIG. 5;

[Explanation of symbols]

1. Front body, 2. Rear body, 3. Engine,
4 head tube, 5 front fork, 6 front wheel, 7 cowling, 8 radiator, 9 intake port, 1
0: intake duct, 11: fuel tank, 12: intake box, 13: seat rail, 14: seat, 15: shaft, 1
6 swing arm, 17 rear wheel, 21, 31 first frame, 22, 32 second frame, 21a, 21b,
21c, 21d, 21e: pipes constituting the first frame; 23, 33: bosses; 24, 34: bolts.

Claims (2)

[Claims] 1. A first frame made of a pipe material and a second frame made of a plate material, wherein the first frame constitutes a skeletal portion, and the second frame is detachably attached to the first frame via fixing means. A motorcycle frame, characterized in that it can be used. 2. The motorcycle frame according to claim 1, wherein said first frame is made of aluminum, titanium or iron, and said second frame is made of fiber reinforced resin or aluminum. flame.