JP2881697B2 - Motorcycle body frame - Google Patents

Description

Description: TECHNICAL FIELD [0001] The present invention relates to a motorcycle body frame provided with only one shock absorber for rear wheels at the center of the vehicle width.

(Prior art)

As a rear wheel shock absorber for motorcycles, there is one in which only one shock absorber is provided at the center of the vehicle width. As disclosed in Japanese Patent Application Laid-Open No. Sho 60-199747, this single shock absorber is provided between a frame member connecting between a pair of left and right main frame rear ends and a rear arm. ing. In such a configuration, since the frame member needs to have sufficient rigidity to support the reaction force from the rear wheel, its shape is wide in the front-rear direction, and furthermore, It extends in substantially the same direction as the longitudinal direction.

However, if the frame member is wide in the front-back direction and is further provided along the longitudinal direction of the shock absorber, not only is it difficult to check the shock absorber from the side of the vehicle body, but also it is difficult to insert a hand. Have difficulty. For this reason, the fact is that the maintainability when maintaining the shock absorber was extremely poor.

[Problems to be solved by the invention]

An object of the present invention is to improve the maintainability of a shock absorber while securing the rigidity of a frame member that supports the shock absorber in a motorcycle in which only one shock absorber for the rear wheel described above is arranged at the center of the vehicle width. It is an object of the present invention to provide an improved body frame.

[Means for solving the problem]

The present invention to achieve the above object has a pair of left and right main frames having a vertically-long rectangular cross section extending obliquely downward from a head pipe to above a rear arm pivot, and installing a fuel tank on an upper surface of the main frame. In a motorcycle provided with a frame member connecting the rear ends thereof between the rear ends of the left and right main frames, and a single shock absorber extending vertically between the frame member and the rear arm, A bottom wall connecting the frame members between the left and right main frame rear end inner wall surfaces and an intermediate portion in the height direction thereof in a substantially linear manner, and obliquely inwardly upward from both rear end inner wall upper ends. A structure having both inclined walls extending, and forming a substantially triangular hollow space in rear view from the bottom wall, the inclined wall, and the inner wall at the rear end of the main frame. Front and The rear surface is sealed by the front and rear walls to form a box having a predetermined thickness, and the widthwise central portion of the frame member intersects with the longitudinal direction of the shock absorber in side view from between the left and right main frame rear ends. The shock absorber is formed so as to project obliquely rearward and upward so as to have an inverted V-shape with the shock absorber whose upper end is connected to the projecting frame member.

〔Example〕

In the embodiment shown in FIGS. 1 to 5, 1 is a main frame, 2 is an engine, 3 is a front wheel, and 4 is a rear wheel.

The main frame 1 is formed by welding the outer panel 1o and the inner panel 1i so as to be hollow so that the vertical cross section becomes a vertically long and substantially rectangular shape, and has a wide band shape in a side view. The main frame 1 is provided as a pair of left and right sides, each having a front end connected to the head pipe 5 and extending obliquely downward. At the rear end, a cast stay portion 20 having a shape bent downward in a hook shape is connected.

The main frame 1 has a suspension portion 31 extending downward at an intermediate portion. The head of the engine 2 is fixed to the suspension portion 31 with bolts 32, and the rear end of the main frame 1 and the stay portion 20 are fixed.
The rear part of the engine is fixed by bolts 33 and 34, respectively. The suspension portion 31 is formed so that the outer panel 1o of the main frame 1 extends without any joint, and is formed by welding an inner panel 35 made of cast or machined to the back side. In this way, the suspension 31 is
The seamless construction with the 1o extension allows the strength to be secured without increasing the thickness of the stress concentration applied to this portion.

On the upper surface of the main frame 1, a fuel tank 36 is mounted via a rubber cushion 37, and the front part is fixed to the main frame 1 and the rear part is fixed to the frame member 8 by bolts 38, respectively. . The stay portion 20 has a rear arm pivot 6, and the rear arm 7 is pivotally supported by the arm pivot 6. Also, a rear wheel 4 is provided at the rear end of the rear arm 7.
Is supported.

A frame member 8 is connected between the rear ends of the pair of left and right main frames 1,1. On the other hand, links 10 and 11 are connected between the lower end of the stay portion 20 and the intermediate portion of the rear arm 7,
The shock absorber 9 is connected between the link 11 and the center of the frame member 8 in the width direction.

The frame member 8 is formed by welding together members 8a, 8a having a right-angled triangle in a cross section in the width direction, and cross members 8b, 8c connecting the upper and lower portions between them. Further, the frame member 8 thus formed has a hollow inside, and is used as the oil tank 21. The oil tank 21 forms a lower chamber 21a and an upper chamber 21b that communicate with each other. Reference numeral 22 denotes an oil inlet of the oil tank 21, and reference numeral 23 denotes an oil outlet.

If this frame member 8 is described in more detail, a bottom wall 8X that connects between the inner side walls 1a, 1a at the rear end portions of the left and right main frames 1, 1 and an intermediate portion in the height direction thereof in a substantially linear manner, Both rear end inner walls
1a, both inclined walls 8 extending obliquely upward from the upper end
The bottom wall 8X, the inclined walls 8Y, 8Y, and the inner walls 1a, 1a form a substantially triangular hollow chamber as viewed from the rear. The front and rear surfaces of the hollow chamber are sealed by front and rear walls 8m and 8n to form a box-shaped oil tank 21 having a predetermined thickness. In addition, the widthwise central portion of the frame member 8 projects obliquely rearward and upward from between the rear ends of the left and right main frames 1 and 1 so as to intersect the longitudinal direction of the shock absorber 9 in side view. Frame member 8
The upper end is connected to the shock absorber 9 in an inverted V-shaped arrangement. As described above, by making the frame member 8 substantially triangular in rear view, it is possible to maintain sufficient rigidity against the reaction force from the rear wheel 4. In addition, since the frame member 8 is formed in a box shape sealed with the front and rear walls 8m and 8n, rigidity can be secured while the front and rear width of the frame member 8 is made compact, whereby the frame member 8 is installed on the upper surface of the main frame in front of the frame member 8. The space of the fuel tank 36 is widened, and a large fuel tank can be installed. Further, since the frame member 8 intersects with the longitudinal direction of the shock absorber 9 in a side view as described above, the frame member 8 can be easily peeped from the side of the vehicle body, and a hand can be inserted. Necessary maintenance work can be performed.

Further, a box 13 for housing the battery 12 is attached to the frame member 8. Also box 13
The stay 14 is fixed to the
15 are suspended. The front end of the seat cowl 16 is fixed to the frame member 8 by bolts 17.

 6 and 7 show another embodiment of the present invention.

In this embodiment, the lower end of the shock absorber 9 is directly pivotally supported with respect to the rear arm 7, and is connected without a link as in the first embodiment. The internal space of the frame member 8 is
It does not have a vertically separated form as in the first embodiment, but the whole is an oil tank 21 of one space.
Further, in this embodiment, the seat cowl 16 is
Are supported by being fixed by bolts 39.

However, the frame member 8 is the same as that of the first embodiment, and a substantially straight line is formed between the inner walls 1a, 1a at the rear end portions of the left and right main frames 1, 1 and between the intermediate portions in the height direction. Connecting bottom wall
8X and both inclined walls 8Y, 8Y extending obliquely upward from the upper ends of the rear end inner walls 1a, 1a, respectively, from the bottom wall 8X, the inclined walls 8Y, 8Y, and the inner walls 1a, 1a. It is formed so as to form a substantially triangular hollow chamber in rear view. The front and rear surfaces of the hollow chamber are sealed by front and rear walls 8m and 8n to form a box-shaped oil tank 21 having a predetermined thickness. The center part of the frame member 8 in the width direction is the left and right main frames 1, 1
And a reverse V-shape with a shock absorber 9 whose upper end is connected to the frame member 8 projecting obliquely rearward and upward so as to intersect the longitudinal direction of the shock absorber 9 in a side view from between the rear ends. It is in a relationship. The configuration is substantially the same as that of the first embodiment. Therefore, the frame member 8 also maintains sufficient rigidity against the reaction force from the rear wheel 4, allows the shock absorber 9 to be easily peeped from the side of the vehicle body, and allows the hand to be attached to the vehicle body frame. And perform necessary maintenance work.

[Effect of the Invention] As described above, in the present invention, the widthwise central portion of the frame member projects obliquely rearward and upward from between the left and right rear ends of the main frame so as to intersect the longitudinal direction of the shock absorber in side view. The frame member and the shock absorber whose upper end is connected to the projecting frame member are formed in an inverted V-shape, so that the frame member and the shock absorber do not overlap in side view, and the shock absorber from the side of the vehicle body. Can be easily peeped out, and the hand can be easily put in for inspection, so that the maintainability of the shock absorber is remarkably improved.

In addition, the frame member extends substantially obliquely inward from upper ends of the rear end inner wall surfaces, and a bottom wall that connects the left and right main frame rear end inner wall surfaces and the intermediate portion in the height direction in a substantially linear manner. The frame member has both inclined walls, and the bottom wall, the inclined wall, and the inner wall at the rear end of the main frame form a substantially triangular hollow chamber in rear view, so that the frame member is stable in rear view. It becomes a highly truss-shaped, and is connected as a cross pipe to the left and right main frames with a vertically long rectangular cross-section and is firmly supported by the main frame, so it is resistant to the reaction force acting on the frame member from the rear wheel via the shock absorber On the other hand, sufficient rigidity can be secured.

Furthermore, since the front and rear surfaces of the hollow chamber are sealed with front and rear walls to form a box having a predetermined thickness, rigidity can be ensured while reducing the front and rear width of the frame member. The space for the fuel tank installed in the vehicle can be increased, and the size of the fuel tank can be increased.

[Brief description of the drawings]

1 to 5 show a motorcycle having a vehicle body frame according to the present invention. FIG. 1 is a sectional view taken along the line CC in FIG. 5, and FIG. 2 is a view showing a fuel tank and a seat cowl in FIG. FIG. 3 is a view taken in the direction of arrow D with the state removed, and FIG.
FIG. 4 is a sectional view taken along the arrow BB in FIG. 5, and FIG. 5 is a side view of the motorcycle. 6 and 7 show a motorcycle having a body frame according to another embodiment of the present invention. FIG. 6 is a sectional view taken along the line EE in FIG. 7, and FIG. 7 is a side view of the motorcycle. FIG. 1 ... main frame, 1a ... inner wall, 2 ... engine, 3
... front wheel, 4 ... rear wheel, 5 ... head pipe, 6 ... rear arm pivot, 7 ... rear arm, 8 ... frame member, 8X ... bottom wall, 8Y ... inclined wall, 8m ... Front wall, 8n Rear wall, 9 Shock absorber, 36 Fuel tank

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B62K 11/02

Claims (1)

(57) [Claims] 1. A pair of left and right main frames having a vertically-long rectangular cross section extending obliquely downward from a head pipe to above a rear arm pivot, a fuel tank is provided on an upper surface of the main frame, and the left and right main frames are provided. A motorcycle provided with a frame member connecting these rear ends to each other between the rear ends, and a shock absorber extending vertically extending between the frame member and the rear arm; A bottom wall that connects the left and right main frame rear end inner wall portions and an intermediate portion in the height direction thereof in a substantially linear manner, and two inclined walls extending obliquely inward and upward from upper ends of the rear end inner wall surfaces, respectively. And a bottom wall, an inclined wall, and a rear end inner wall of the main frame are formed to form a substantially triangular hollow chamber in rear view, and the front and rear faces of the hollow chamber are formed. Dense on the front and rear walls Closed and formed into a box shape of a predetermined thickness, and the width direction center portion side of the frame member is obliquely rearwardly intersecting the longitudinal direction of the shock absorber in a side view from between the left and right main frame rear end portions. A vehicle body frame for a motorcycle, wherein the vehicle body frame is formed to project upward and form an inverted V-shape with the shock absorber having an upper end connected to the projecting frame member.