JPH09240550A - Body frame of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure strength required for a connecting part by eliminating inconvenience on the appearance of the connecting part for welding frame members to each other, and by restraining the rise of cost and the increase of weight to the minimum extent. SOLUTION: A pivot frame 16 is casting material or made of a casting material, and a projecting part 20 cylindrically projecting is integrally formed on a part (equivalent to a connecting part) on the upper part to be connected to an upper part frame 12a. A cutout part 22 is formed on the side part facing the body inner side in the rear end (equivalent to the connecting part) 24 of the upper part frame part 12a. The projecting part 120 is fitted to the rear end 24 of the upper part frame part 12a, and the rear end edge 24a and the edge 22a of the cutout part 22 are welded to the pivot frame 16 (mainly, the front surface of the projecting part 20 and the base part of the projecting part 20) over the whole circumference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a body frame of a motorcycle for fixing a connecting portion (welding joint) between frame members by welding.

[0002]

2. Description of the Related Art Conventionally, in a motorcycle frame, a tank rail or the like is formed of a round pipe frame member, and a pivot frame or the like is formed of a frame member formed of a cast part or a forged part, and a connecting portion ( Weld joints) may be fixed by welding. For example, FIG.
And as shown in FIG. 6, a protrusion b is formed from a pivot frame a made of the above-mentioned type of cast or forged component, and the protrusion b is fitted into a pipe frame c end c1 made of a round pipe material, Welding f is performed over the entire circumference of the edge portion of the pipe frame end portion c1.

[0003]

However, when the welding f length can be obtained only by the circumference of the round pipe and the strength of the connecting portion cannot be sufficiently obtained, as shown in FIG. The end portion d1 is cut off obliquely, or the reinforcement hose e, which is a reinforcing material, is applied to the connecting portion between the pipe frame c and the pivot frame a, as shown in FIG. 8, to secure the length of the welding f, Although the strength is improved, there are problems that a long welded portion is visible from the outside and is defective in appearance, and that it leads to cost increase and weight increase.

Regarding the structure of the welded portion, JP-A-60
No. -56688 discloses a technique of fitting a pipe to a fitting member having a substantially U-shaped cross section and fixing it by welding, but it is not a structure in which the connecting portion of the pipe material is fitted, and the fitting member is As it leads to an increase in weight and the long welds are noticeable,
Inability to resolve defects in appearance.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and eliminates a defect in appearance of a connecting portion for welding frame members to each other, and minimizes an increase in cost and an increase in weight. An object of the present invention is to provide a vehicle body frame of a motorcycle that can secure the necessary strength of the connecting portion.

[0006]

The present invention has the following constitution in order to solve the above problems. According to the invention of claim 1, in a vehicle body frame in which a connecting portion between frame members is fixed by welding, a projecting portion is integrally formed with a connecting portion of a first frame member made of a cast material or a forged material, and a pipe is formed. A second frame member connecting portion made of a material, a notch portion is formed in a portion facing the inner side of the vehicle body, and the projecting portion is fitted into the second frame member end portion so that the edge portion and the notch portion are formed. A vehicle body frame for a motorcycle, wherein a partial edge portion is welded to a first frame member.

According to the first aspect of the present invention, in the body frame, the notch portion is formed at the end of the second frame member connecting portion inwardly of the vehicle body. Therefore, the notch portion is inconspicuous in appearance. The long welded part does not stand out even if it is welded. Further, since the protruding portion of the first frame member is fitted into the end portion of the second frame member and the end edge portion and the notched partial edge portion are welded to the first frame, the second frame member In addition to the end edge portion, the edge portion of the cutout portion can be welded, so that the welding length can be increased. Further, since the notch is simply provided, the increase in cost and weight can be minimized.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory view of a vehicle body frame of a motorcycle according to an embodiment of the present invention, FIG. 2 is a partially enlarged explanatory view of a main part seen from the inside of the vehicle body, FIG. 3 is a sectional view of FIG. 2, and FIG. It is explanatory drawing of a principal part.

As shown in FIG. 1, a vehicle body frame of a motorcycle includes an upper frame portion (second frame) made of a round pipe material having a circular cross section in which a main frame 12 extending in a left-right pair rearward from a head pipe 10 serves as a tank rail. (Corresponding to a frame member) 12a and a lower frame portion 12b made of a pipe material having a rectangular cross section for suspending the engine. A pivot frame (corresponding to a first frame member) 16 that pivotally supports a swing arm (not shown) by a pivot shaft 14 is arranged at the rear end of the main frame 12 so as to extend substantially vertically. The frame 16 is fixed by welding. The present invention is mainly embodied in a connecting portion (indicated by reference numeral 18) between the upper frame portion 12a and the pivot frame 16.

The pivot frame 16 is made of cast material or forged material, and as shown in FIG. 4, the upper frame 12a.
A projecting portion 20 projecting in a hollow cylindrical shape, for example, is integrally formed at an upper portion (corresponding to a connecting portion) connected to
Also, the rear end of the upper frame portion 12a (corresponding to the connecting portion)
The rear end edge 24a is provided at a side portion facing the inside of the vehicle body.
To form a cutout portion 22 by making an elongated cut in the longitudinal direction of the frame.

As shown in FIGS. 2 and 3, the protrusion 20 is formed.
Is fitted into the rear end portion 24 of the upper frame portion 12a, and the rear end edge portion 24a and the cutout portion 22 edge portion 22a are welded to the pivot frame 16 (mainly the surface of the protruding portion 20 and the base portion of the protruding portion 20) over the entire circumference. I'm doing 26. In addition,
The base of the protrusion 20 has a step 20a,
When the fitting is inserted, the rear edge portion 24a of the upper frame portion 12a abuts on the step portion 20a, and the welding 26 may be located at a position separated from the pivot frame 16 by the step portion 20a, which facilitates the welding operation.

Therefore, the rear end portion 2 of the upper frame 12a
4 is formed by cutting the rear end edge portion 24a in the longitudinal direction of the frame to form a cutout portion 22 in the portion facing the inside of the vehicle body. Therefore, the cutout portion 22 becomes a portion that is inconspicuous in appearance, and even if it is welded there. Long welds are inconspicuous.

Further, since the protruding portion 20 of the pivot frame 16 is fitted into the rear end portion 24 of the upper frame 12a and the rear end portion 24 edge portion 24a and the cutout portion 22 edge portion 22a are welded to the pivot frame 16. Upper frame 1
The edge portion 22a of the cutout portion 22 can be welded in addition to the rear end edge portion 24a of 2a, so that the welding length can be increased. Further, since the notch 22 is simply provided, cost and weight increase can be minimized.

[0014]

As described above, according to the present invention, the second
Since a cutout portion is formed at the end of the frame member connecting portion facing the inside of the vehicle body, the cutout portion is inconspicuous in appearance, and a long welded portion is inconspicuous even when welding there. Further, since the protruding portion of the first frame member is fitted into the end portion of the second frame member and the end edge portion and the notched partial edge portion are welded to the first frame, the second frame member In addition to the end edge portion, the edge portion of the cutout portion can be welded, so that the welding length can be increased. Further, since the notch is simply provided, the increase in cost and weight can be minimized.

[Brief description of drawings]

FIG. 1 is an explanatory side view of a vehicle body frame of a motorcycle according to an embodiment of the present invention.

FIG. 2 is a partially enlarged explanatory view of a main part as viewed from the inside of the vehicle body.

FIG. 3 is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an explanatory diagram of a main part before connection.

FIG. 5 is an explanatory diagram of an example of a conventional connecting portion.

FIG. 6 is an explanatory view of a connecting portion of FIG.

FIG. 7 is an explanatory view of another example of the conventional connecting portion.

FIG. 8 is an explanatory view of still another example of the conventional connecting portion.

[Explanation of symbols]

 12 Main Frame 12a Upper Frame 16 Pivot Frame 18 Welding Point 20 Projection 22 Notch Part 22a Edge of Notch Part 24 Upper Frame Rear End 24a Edge of Upper Frame Rear End

Claims (1)

[Claims] 1. In a vehicle body frame in which a connecting portion between a frame member and a frame member is fixed by welding, a projecting portion is integrally formed at a connecting portion of a first frame member made of a cast material or a forged material, and a pipe material is formed. A cutout portion is formed at an end portion of the second frame member connecting portion facing inward of the vehicle body, and the projecting portion is fitted into the end portion of the second frame member to form the end edge portion and the cutout portion edge. A body frame for a motorcycle, wherein a portion is welded to a first frame member.