JPH072385Y2 - Motorcycle frame - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial field of application) The present invention relates to a motorcycle frame in which the strength around the head pipe is improved and welding marks do not appear on the outer surface.

(Prior Art) Conventionally, a frame of a motorcycle is assembled by molding a metal tube or a channel member into a desired shape for each part and connecting these molding members. And
Welding means are mainly provided for the connections.

In a motorcycle composed of a metal tube, a connecting member is welded to the head pipe, and the tank rail and down tube are fixed to this connecting member, and the engine is mounted in the space surrounded by this tank rail, down tube, and body tube. To be done. The head pipe supports the front wheel by the fork via the steering shaft and the upper and lower brackets, and the rear wheel is supported on the free end side of a swing arm attached to the lower rear part of the down tube and the body tube.

For this reason, in the motorcycle, stress is likely to concentrate around the head pipe and the lower part of the body tube, and particularly the tank rail and the down tube gather around the head pipe, and the cross-sectional area of the frame is small, which is stressful. In a conventional motorcycle, a reinforcing bridge is provided on a connecting member around a head pipe where stress is concentrated, and this portion is reinforced to enhance frame strength and rigidity.

(Problems to be solved by the invention) In a conventional motorcycle, the connecting member is reinforced by interposing a reinforcing bridge, but since the reinforcing structure is complicated and complicated, there are many welding points and welding work and While it is difficult to assemble, it often impairs the aesthetic appearance, and there is a problem in weight reduction.

The present invention has been made in consideration of the above circumstances, and provides a motorcycle frame that can improve strength around the head pipe where stress is likely to concentrate, improve aesthetic appearance, and further reduce weight. The purpose is to do.

[Constitution of device]

(Means for Solving Problems) A motorcycle frame according to the present invention includes a frame head made of casting and a pair of left and right main frames made of press, and the frame head includes a head pipe portion and the head. The main frame consists of a pair of left and right main frames, each of which has a U-shaped cross section and is secured to an inner panel and an outer panel. While, the front end of the inner panel constituting the main frame is abutted and fixed to the rear end of the continuous portion, while extending the front end of the outer panel to the head pipe portion side from the front end of the inner panel, The front end of the outer panel is fixed along the outer side of the vehicle body of the connecting portion, and is also fixed by contacting with the head pipe portion.

(Operation) The frame head is made of casting and is integrally formed by casting. Further, the inner panel front end of the main frame is abutted and fixed to the rear end portion of the connecting portion, and the outer panel of the main frame is fixed along the vehicle body outer side portion of the connecting portion, and the outer panel abuts on the head pipe portion. It is fixed.

Therefore, the width of the fixed portion between the outer panel and the connecting portion of the frame head, which is a cast-integrated component, can be increased, and the strength around the head pipe where stress is likely to concentrate is improved.

Further, since the outer panel is fixed to the connecting portion from the outside, the welding mark between the inner panel and the connecting portion cannot be seen from the outside, and the appearance shape is simplified and the aesthetic appearance is improved.

Further, since the fixing portion of the outer panel and the connecting portion and the whole main frame are formed in the hollow shape of the middle fitting structure, and the connecting member for reinforcement provided around the head pipe is not necessary, the weight is greatly reduced. You can contribute.

(Embodiment) An embodiment of the frame of the motorcycle according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, reference numeral 10 indicates a vehicle body frame of a motorcycle, and the vehicle body frame 10 is composed of a frame head 11 made of casting and a pair of left and right main frames 12 and 13 fixed to the frame head 11. . The frame head 11 integrally includes a head pipe portion 11a that supports the steering shaft 15 by casting, a front fork 17 is connected to the steering shaft 15 via a bracket 16, and a front wheel 18 is rotatably supported at a lower end thereof. It

On the other hand, the main frames 12 and 13 are attached so as to extend obliquely downward from the frame head 11, and pivot parts 12a and 13a are formed at the rear ends thereof. Mainframe 12,13
An engine bracket 20 is attached to substantially the center lower end of the engine bracket 20 and the pivot part 12a,
Engine 21 is mounted between 13a and 13a.

A swing arm 22 is swingably supported in a cantilever manner in the middle of the pivot parts 12a, 13a, and a rear wheel 23 is held at a free end of the swing arm 22. The swing of the swing arm 22 is absorbed by the buffer unit 24, and the vibration of the rear wheel 23 during traveling is prevented from being directly transmitted to the vehicle body frame 10.

A seat rail 26 is fixed to the upper rear part of the body frame 10. The seat rail 26 extends obliquely upward from the body frame 10 toward the rear, and the seat 27 is attached to the extension thereof. A fuel tank 29 is arranged in front of the seat 27.

By the way, as shown in FIG. 2, the frame head 11 has a head pipe portion 11a that pivotally supports a steering shaft 15.
And a connecting portion 11b that expands rearward from the head pipe portion 11a in a figure eight shape. The head pipe portion 11a and the connecting portion 11b are integrally formed by casting. As a material of the frame head 11, a light metal such as an aluminum material or a light alloy such as an aluminum alloy is used.

On the other hand, the main frames 12 and 13 are respectively fixed to the inner panel 30 made of a press having a U-shaped cross section by welding so that the outer panel 31 made of a press having the same U-shaped cross section is wrapped from the outside to form a centering structure. It is formed. Like the frame head 11, the main frames 12 and 13 are also made of a light alloy such as an aluminum material or an aluminum alloy.

The front end of the inner panel 30 forming the main frames 12 and 13 is brought into contact with the rear end of the connecting portion 11b of the frame head 11 and fixed by welding. Further, the front end of the outer panel 31 is extended toward the head pipe portion 11a side from the front end of the inner panel 30, and the extended portion is fixed by welding along the vehicle body outer side portion of the continuous portion 11b. , The tip of the extended part is the head pipe part 11a
Is abutted on and fixed to.

The fixing portion between the outer panel 31 and the connecting portion 11b is formed in the middle structure so that the outer panel 31 wraps the connecting portion 11b from the outside of the vehicle body as shown in FIG. 3, and is hollow like the main frames 12 and 13. -It is lightweight.

As described above, in the above embodiment, the frame head 11 is integrally formed by casting, the front end of the inner panel 30 abuts on the connecting portion 11b of the frame head 11 and is fixed by welding, and the connecting portion is also formed. The outer panel 31 is applied to the outer side of the vehicle body of 11b and fixed by welding, and the front end of the outer panel 31 is fixed by abutting against the head pipe 11a.

Since the connecting portion 11b is a cast-integrated part together with the head pipe portion 11a, as shown in FIG. 4, the width A of the fixed portion between the outer panel 31 and the connecting portion 11b is made large, and a sufficient cross-sectional area of this portion is secured. can do.

Therefore, the strength around the head pipe portion 11a where stress is likely to be concentrated is greatly improved. A plurality of reinforcing ribs (not shown) may be integrally formed in the connecting portion 11b at the time of casting, if necessary.

Further, the fixed portion between the outer panel 31 and the connecting portion 11b and the entire main frames 12 and 13 are formed in a hollow shape having a centering structure, and a connecting member for reinforcement conventionally provided around the head pipe, etc. Since it becomes unnecessary at all, it can greatly contribute to weight reduction.

By the way, since the frame head 11 is made of casting, the welding portion is only between the main frames 12 and 13 and the connecting portion 11b and only a part of the head pipe portion 11a, and the number of welding points is reduced and the outer panel 31 Are welded and fixed so as to wrap the connecting portion 11b and the inner panel 30 from the outside, the welding traces between the inner panel 30 and the connecting portion 11b and the welding traces between the outer panel 31 and the connecting portion 11b cannot be seen from the outside. , The aesthetics are greatly improved. Furthermore, the burden on the manufacturing worker is reduced by reducing the number of welding points.

[Effect of device]

As described above, the motorcycle frame according to the present invention includes a casting frame head and a pair of left and right main frames made of a press, and the frame head includes a head pipe portion and a head pipe portion. The pair of left and right main frames are formed to have a centering structure in which an inner panel and an outer panel each having a U-shaped cross section are fixed to each other. , While the front end of the inner panel constituting the main frame is abutted and fixed to the rear end of the continuous portion, the front end of the outer panel is extended to the head pipe portion side from the front end of the inner panel, the front end of the outer panel The fixed portion is fixed along the outer side of the vehicle body of the continuous portion, and is also fixed in contact with the head pipe portion.

Therefore, the strength around the head pipe where stress is likely to be concentrated can be improved, the aesthetic appearance can be improved, and the weight can be further reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a motorcycle incorporating an embodiment of the frame structure of the motorcycle according to the present invention, FIG.
FIG. 3 is a perspective view showing the structure of the above embodiment, FIG. 3 is a sectional view taken along the line III--III in FIG. 2, and FIG. 4 is a plan view of the vicinity of the frame head of the above embodiment. 10 …… Body frame, 11 …… Frame head, 11a ……
Head pipe part, 11b …… Connecting part, 12,13 …… Main frame, 12a, 13a …… Pivot part, 30 …… Inner panel, 3
1 …… Outer panel.

Claims (1)

[Scope of utility model registration request] 1. A frame head made of casting and a pair of left and right main frames made of a press, the frame head being connected to a head pipe portion and extending from the head pipe portion rearward in a figure eight shape. On the other hand, the pair of left and right main frames are formed in a centering structure by fixing an inner panel and an outer panel having a U-shaped cross section, and the front end of the inner panel constituting the main frame is formed as described above. The front end of the outer panel is extended toward the head pipe part side of the front end of the inner panel, while being fixed to the rear end of the continuous part, and the front end of the outer panel is fixed along the outer side of the vehicle body of the continuous part. In addition, the frame of the motorcycle is characterized in that the frame is brought into contact with and fixed to the head pipe portion.