JP2941261B2 - Motorcycle main frame structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle main frame structure in which vibration is absorbed and rigidity is improved.

[0002]

2. Description of the Related Art Some motorcycle frames have a rectangular cross section formed by, for example, pressing a pair of divided frame portions formed into a U-shape cross section by press working and facing each other. The frame having the square cross section has advantages such as light weight and rigidity as compared with the round cross section frame, and is used for a main frame or the like.

[0003]

Since a conventional frame having a rectangular cross section has a wide flat portion, when the flat portion vibrates due to driving of the internal combustion engine, the frame portion resonates to generate a resonance sound. The noise due to the vibration of the frame having the rectangular cross section gives the rider discomfort. For this reason, in order to reduce the vibration of the plane portion of the frame having the rectangular cross section, it is conceivable to increase the rigidity by making the frame thicker.
When the thickness is increased, there is a problem that the weight increases and the production cost increases. An object of the present invention is to reduce vibration and noise of a frame having a rectangular cross section with a simple structure in a main frame structure of a motorcycle.

[0004]

According to the present invention, the upper and lower ends of an outer divided frame portion having a U-shaped cross section and the upper and lower ends of an inner divided frame portion having a U-shaped cross section are welded. A main frame with a rectangular cross section was formed, the front end of the left and right integrated main frame was connected to the head pipe, the left and right integrated rear arm brackets were arranged at the rear of each main frame, and the fuel tank was mounted on the main frame In the motorcycle main frame structure, the length of the head pipe and the vertical width of the front end of the main frame are substantially the same length, and the inner surface of the flat portion of the outer split frame portion and the inner surface of the flat portion of the inner split frame portion are separated from each other. An anti-vibration device is mounted between the anti-vibration devices. The anti-vibration device directly contacts an elastic body made of a pre-molded rubber material with the inner surface at the center in the vertical direction of the plane portion of the outer divided frame portion. In addition, the first structure is that the elastic body is assembled in a compressed state between the inner surfaces of the two flat portions so that a gap is formed between the upper and lower portions of the elastic body and the upper end and the lower end of the main frame. I do. The present invention is characterized in that, in the first configuration, a plurality of synthetic resin bodies are mounted at an interval between the inner surface of the flat portion of the outer divided frame portion and the inner surface of the flat portion of the inner split frame portion. The second configuration is used.

[0005]

1 to 7 show an embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a body frame of a motorcycle, and a front fork 3 is pivotally fitted to a head pipe 2 constituting the body frame 1, and a front wheel 4 is provided on the front fork 3. . The front ends of a pair of left and right main frames 5 are connected to the head pipe 2, and the length of the head pipe 2 and the vertical width of the front end of the main frame 5 are substantially the same. A pair of left and right rear arm brackets 6 are disposed at the rear of the main frame 5. The pair of left and right rear arm brackets 6 are integrally provided with a pair of left and right seat rails 7 that rise up diagonally rearward and extend rearward, and a seat 8 is placed on the seat rails 7.

[0006] An internal combustion engine 9 is mounted on the main frame 5 and the rear arm bracket 6, and a fuel tank 10 is mounted above the internal combustion engine 9 from the main frame 5 to the front side of the seat rail 7. Further, a fairing 11 covers from the front side of the front fork 3 to both sides of the internal combustion engine 9. A pair of left and right rear arms 12 pivotally supported by the rear arm bracket 6 are connected at the front side by a support pipe, and further connected to a cross pipe 14 slightly forward from the center. The support pipe of the rear arm 12 is supported by a pivot shaft 15, and the rear arm 12 is further pivotally supported by the pivot shaft 15.
Can be swung around the fulcrum. The rear arm bracket 6 and a bracket 16 provided on the cross pipe 14 of the rear arm 12 are connected by a link mechanism 17.
A rear cushion 18 is provided between the vehicle and the seat rail 7. A rear wheel 20 is supported at the rear of the rear arm 12 via an axle 19. In FIG. 1, reference numeral 60 denotes a vibration isolator 60 described later, and reference numeral 162 denotes a rubber plate mounted between the inner and outer frames of the rear arm 12.

The main frame 5 is constructed as shown in FIGS. 2 to 4. The front end 5a of the main frame 5 is attached to the head pipe 2 and the rear end 5b is attached to the rear arm bracket 6 by welding. The main frame 5 is formed by welding an outer divided frame portion 50 and an inner divided frame portion 51 having a U-shaped cross section formed by press working of aluminum and has a square cross section. The upper end portion 50a and the lower end portion 50b of the outer split frame portion 50 are welded to the upper end portion 51a and the lower end portion 51b of the inner split frame portion 51, and the flat portion 50c and the inner split frame portion 51 of the outer split frame portion 50 are formed. The flat part 51c is arranged to face the same.

In the embodiment, the main frame 5 is provided with anti-vibration devices 60, 70, 80,
0,140, and the anti-vibration devices 60, 70, 80, 90, 140 are configured as shown in FIGS. The rubber 62 of the holding plate 61 of the vibration isolator 60 is bonded to the inside of the flat portion 50c of the outer divided frame portion 50, and the rubber 64 of the holding plate 63 is bonded to the inside of the flat portion 51c of the inner split frame portion 51. . A support stay 65 is provided between the holding plates 61 and 63.
Are provided, and the rubber stays 62, 6
4 is pressed against the flat portion 50c of the outer split frame portion 50 and the flat portion 51c of the inner split frame portion 51. The rubber (elastic body) 62 shown in FIG. 4 is made of a rubber material that has been molded in advance, and the rubbers 71, 82, 84, 9 shown in FIGS.
2, 141 is the same.

As described above, the main frame 5 having the rectangular cross section
Has a wide plane portion, and thus vibrates when the internal combustion engine is driven. This vibration is absorbed by the rubbers 62 and 64 of the vibration isolator 60, thereby suppressing resonance. Accordingly, the generation of the resonance sound of the main frame 5 is reduced, and the noise caused by the vibration of the frame having the rectangular cross section is prevented from giving the rider a feeling of discomfort. Further, the vibration isolator 60 includes a flat portion 50c of the outer divided frame portion 50 and an inner divided frame portion.
The support stay 65 is provided between the flat portion 51c of the outer split frame portion 50 and the flat portion 51c of the inner split frame portion 51. And the rigidity is improved.

FIG. 5 shows another vibration isolator 70 in the embodiment.
Here is an example using. In this example, the vibration isolator 70 is provided between the inner surface of the flat portion 50c of the outer divided frame portion 50 of the main frame 5 and the inner surface of the flat portion 51c of the inner divided frame portion 51. In this vibration isolator 70, a rubber (elastic body) 71 made of a rubber material formed in advance is prepared, and this rubber 71 is brought into direct contact with the inner surface of the central part of the plane parts 50c, 51c in the vertical direction. Then, it is bonded in a compressed state between the inner surfaces of the flat portions 50c, 51c so that a gap is formed between the upper and lower surfaces of the rubber 71 and the upper ends 50a, 51a and the lower ends 50b, 51b of the main frame 5. I have. The vibration isolator 70 absorbs vibration similarly to the vibration isolator 60, and also has the flat portions 50c, 51.
The rigidity of c is improved. In addition, rubber 71
Is mounted between the plane portions 50c and 51c, and is not mounted on the curved portions of the outer divided frame portion 50 and the inner divided frame portion 51.

FIG. 6 shows another vibration isolator 80 in the embodiment.
Here is an example using. In this example, the rubber 82 of the holding plate 81 is adhered inside the flat portion 50c of the outer divided frame portion 50 of the main frame 5, and the rubber 84 of the holding plate 83 is also adhered inside the inner divided frame portion 51. I have. Bolts 85 from outside of the inner divided frame portion 51
c, through the rubber 84 and the holding plate 83, is screwed to the nut 86 of the holding plate 81 of the outer divided frame portion 50,
The rubber 82 is pressed against the flat portion 50 c of the outer divided frame portion 50 via the holding plate 81 by the rotation of the bolt 85. Rubber 84 provided on the flat portion 51c of the inner divided frame portion 51
Since the holding plate 83 is not pressed against the flat portion 51c by the bolt 85, the holding plate 83 functions as a dynamic damper and suppresses vibration.

FIG. 7 shows another vibration isolator 90 in the embodiment.
Here is an example using. In this example, the rubber 92 of the holding plate 91 is bonded to the inside of the plane portion 50c of the outer divided frame portion 50 forming the main frame 5. The flat portion 51c of the inner divided frame portion 51 is bent inward, and when the bolt 93 is passed through from the outside and tightened and fixed with nuts 94 and 95, the rubber 92 is divided by the bolt 93 through the holding plate 91 to the outside. The frame portion 50 is pressed against the flat portion 50c.

FIGS. 8 and 9 show a diagram in which the vibration isolator 140 is applied to the rear arm. However, the vibration isolator 140 can also be applied to the main frame 5 and is included in the embodiment of the present invention. It shall be. In this example, the left and right rear arms
12 (main frame 5) comprises an outer divided frame portion 120 (50) and an inner divided frame portion 121 (51), the upper end portions 120a (50a) and 121a (51a) and the lower end portion 120b, as described above. (50b) and 121b (51b) are welded, and the plane portions 120c (50c) and 121c (51c) are opposed to each other. The left and right rear arms 12 (main frame 5) are provided with vibration isolating devices 140 at three locations.

As shown in FIG. 8, the vibration isolator 140 has a spacer 143 on a holding plate 142 having a rubber 141.
Further, nuts 144 are fixed to the spacers 143 by brazing, respectively. A bolt 145 is screwed to the nut 144, and a holding plate 147 having a rubber 146 is rotatably mounted on the bolt 145. The position of the holding plate 147 is regulated by a collar 148 fixed to the bolt 145. You.

As shown in FIG. 9, the anti-vibration device 140 includes an inner divided frame portion of the rear arm 12 (main frame 5).
The rubber 141 of the holding plate 142 is inserted into the mounting hole 150 formed on the outer frame 121 (51).
Of the holding plate 147.
The rubber 146 is rotated 90 degrees and the inner divided frame 121
When the bolt 145 is rotated in this state by contacting the flat portion 121c (51c) of (51), the interval between the two holding plates 142 and 147 is increased, and the rubber 141 and 146 is moved to the flat portion 120c.
(50c) and 121c (51c) are pressed. This anti-vibration device 14
Even with 0, the vibration of the rear arm 12 is absorbed and the rigidity is improved.

[0016]

According to the present invention, the length of the head pipe is substantially the same as the vertical width of the front end of the main frame, and the inner surface of the flat portion of the outer divided frame portion and the inner surface of the flat portion of the inner divided frame portion are different from each other. An anti-vibration device is installed between the anti-vibration device and the elastic member made of a rubber material that has been formed in advance is brought into direct contact with the inner surface of the central portion in the vertical direction of the two flat portions, and the upper and lower portions of the elastic member. It is bonded in a compressed state between the inner surfaces of the two flat portions so that a gap is formed between the upper end and the lower end of the main frame. Therefore, even if the vibration of the engine is transmitted to the main frame and the wide flat portions of the outer and inner split frame portions of the frame try to vibrate, the elastic body attached between the flat portions is always adhered and separated. Since there is no vibration, the vibration is sufficiently absorbed, the vibration of the frame is suppressed, and the noise is reduced. In addition, since the elastic body is mounted between the inner surface of the flat portion of the outer divided frame portion and the inner surface of the flat portion of the inner divided frame portion in a compressed state, the elastic body becomes a bar between the two flat portions, and The rigidity of the frame portion and the inner divided frame portion is improved. In addition, since the elastic body made of a rubber material formed in advance is bonded in a compressed state to the inner surface at the center in the vertical direction of the two flat portions, vibration can be absorbed in a portion where the vibration amplitude of the two flat portions is the largest. Therefore, the efficiency of vibration absorption is high. Further, there is a gap between the upper and lower walls of the elastic body between the upper and lower walls of the arm portion, so that the assembling work when the elastic body is assembled in a compressed state is easy, and the rubber material is deformed by vibration. Space, and vibration can be effectively absorbed. As described above, since the main frame is not made thick, vibration and resonance noise can be prevented while reducing the weight of the main frame.

[Brief description of the drawings]

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

FIG. 2 is a side view of the main frame according to the embodiment of the present invention.

FIG. 3 is a plan view of the main frame of FIG. 2;

FIG. 4 is a sectional view taken along the line IV-IV in FIG. 2;

FIG. 5 is a sectional view of another example of the vibration isolator.

FIG. 6 is a sectional view of still another example of the vibration isolator.

FIG. 7 is a sectional view of another example of the vibration isolator.

FIG. 8 is a side view of another example of the vibration isolator.

9 is a perspective view showing a state in which the vibration isolator of FIG. 8 is attached to a rear arm.

[Explanation of symbols]

 2 Head pipe 5 Main frame 6 Rear arm bracket 10 Fuel tank 50 Outer split frame part 50a Upper end part 50b Lower end part 51 Inner split frame part 51a Upper end part 51b Lower end part 70 Vibration isolator 71 Elastic body

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruhito Okamoto 2500 Shinkai, Iwata City, Shizuoka Prefecture Inside Yamaha Motor Co., Ltd. (72) Inventor Kiyoshi Kiyoshi 2500 Shinkai, Iwata City, Shizuoka Prefecture Inside Yamaha Motor Co., Ltd. (72) Inventor Kensaku Isobe 2500 Shinkai, Iwata City, Shizuoka Prefecture Inside Yamaha Motor Co., Ltd. (56) References JP-A-62-77292 (JP, A) JP-A-1-247289 (JP, A) Jpn. (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B62K 11/04 F16F 15/02

Claims (2)

(57) [Claims] 1. A main frame having a rectangular cross section is formed by welding the upper end and the lower end of an outer divided frame portion having a U-shaped cross section and the upper end and lower end portion of an inner divided frame portion having a U-shaped cross section. The front end of the left and right integrated main frame is connected to the head pipe, the left and right integrated rear arm brackets are disposed at the rear of each main frame, and the main frame structure of the motorcycle in which the fuel tank is mounted on the main frame, The length of the head pipe and the vertical width of the front end of the main frame are substantially the same length, and a vibration isolator is mounted between the inner surface of the flat portion of the outer split frame portion and the inner surface of the flat portion of the inner split frame portion. The anti-vibration device is configured such that an elastic body made of a rubber material formed in advance is brought into direct contact with an inner surface of a central portion in the vertical direction of a plane portion of the outer divided frame portion, and A main frame structure for a motorcycle, wherein the main frame structure is mounted in a compressed state between inner surfaces of the two flat portions so that a gap is formed between a lower portion and an upper end portion and a lower end portion of the main frame. 2. The motorcycle according to claim 1, wherein a plurality of synthetic resin bodies are mounted at an interval between the inner surface of the flat portion of the outer divided frame portion and the inner surface of the flat portion of the inner split frame portion. Main frame structure.