JPH0777873B2 - Body frame structure for vehicles such as motorcycles - Google Patents

Description

TECHNICAL FIELD The present invention relates to a vehicle body frame structure for a vehicle such as a motorcycle, which is configured by connecting pipe members having rectangular cross sections.

(Prior Art) For example, in a vehicle body frame of a motorcycle, Japanese Patent Laid-Open No. 59-53
There is one disclosed in Japanese Patent No. 285.

According to this, a pair of left and right first pipe members having a rectangular cross section are provided, and a second pipe member having a rectangular cross section extending in a direction substantially along a virtual imaginary plane passing through these first pipe members is provided. The second pipe is formed in the middle of the longitudinal direction of each first pipe member.
The ends of the pipe material are butt welded together.

Further, in the above-mentioned configuration, the first and second pipe members are both square pipes having a rectangular cross section, and the end portion of the second pipe member welded to the first pipe member is arranged with the vehicle body constituent parts. Due to the above-mentioned relationship, it is three-dimensionally bent into a desired shape.

(Problems to be Solved by the Invention) By the way, as described above, bending the rectangular pipe three-dimensionally into a desired shape is extremely complicated in order to secure predetermined accuracy. Therefore, it is not easy to form the body frame with a desired shape with high accuracy and improve the appearance.

Further, when it is attempted to butt-weld the end portion of the second pipe material to the middle portion in the longitudinal direction of the first pipe material, this second
The abutted surface of the middle portion of the first pipe material, which is to be abutted with the end portions of the pipe material, is flat, but it is difficult to position them relative to each other, and therefore the molding of the vehicle body frame is complicated. There is a problem.

Furthermore, in order to improve the overall strength of the body frame,
It is desired that the joint between the midway portion of the first pipe material and the end portion of the second pipe material has sufficient strength. Therefore, it is conceivable to reinforce the joint portion with a reinforcing material. However, if the reinforcing material is simply provided, the number of parts increases and the structure of the vehicle body frame becomes complicated. The appearance of the item may deteriorate.

(Object of the Invention) The present invention has been made by paying attention to the above circumstances, and when the vehicle body frame is formed by joining the first and second pipe members having rectangular cross sections, the external appearance of the vehicle body frame is improved. The appearance of the body frame can be easily improved, and the body frame of the same can be easily formed. Further, the strength of the body frame of the same can be improved with a simple structure and without deteriorating the appearance. The purpose is to let you.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a pair of left and right first pipe members having a rectangular cross section are provided, and a second pipe is provided at an intermediate portion in the longitudinal direction of each of these first pipe members. When the end portions of the material are welded in a butt shape, a pair of sheet metal members having a U-shaped cross section are joined so that their groove portions face each other to form the end portion of the second pipe material. It is a point that a part of the end surface of the end portion in the longitudinal direction of the two pipe materials is extended, and the extending pieces are joined to the mutually opposing surfaces of the left and right first pipe materials and welded.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Reference numeral 1 denotes a vehicle body frame of a motorcycle, in which an engine 2 is supported, and above the vehicle body frame 1, a fuel tank 3 and a seat 4 are supported.

The body frame 1 has a steering shaft tube 6 in the front part thereof, and although not shown, a front fork is supported by the steering shaft tube 6, and front wheels are supported by the front fork. A pair of left and right main pipes 7 having a rectangular cross section are provided so as to project rearward from the upper portion of the steering shaft pipe 6.

Further, a pair of left and right down tubes 8 having a rectangular cross section are provided so as to project rearward from the lower portion of the steering shaft tube 6. Further, seat pillar tubes 9 and 9 each having a rectangular cross section are provided so as to extend obliquely upward from the rear ends of the down tubes 8 and 8. The midway portion of each of the seat pillar tubes 9 in the longitudinal direction is connected to the rear end of the main pipe 7.

Although not shown, a rear arm is pivotally supported by a connecting portion between the down tube 8 and the seat pillar tube 9, and a rear wheel is supported by the rear arm.

A pair of left and right seat rails 11 having a rectangular cross section, which are first pipe members, are provided so as to project rearward from a middle portion of the main pipe 7 in the front-rear direction. On the other hand, the seat pillar tube 9 which is the second pipe member extends in a direction substantially along a vertical virtual surface (corresponding to the paper surface of FIG. 3) passing through the seat rail 11.

The upper end 9a of the seat pillar tube 9 is butt-welded and joined to a midway portion of the seat rail 11 in the longitudinal direction. Battery to this junction
A bracket 13 that supports 12 is projected. Further, a cross member 15 is installed on both seat rails 11 and 11, and a midway portion in the longitudinal direction of the seat pillar tube 9 and a rear end of the seat rail 11 are connected by a back stay 16. The seat 4 is supported on the left and right seat rails 11, 11.

The end portion 9a of the sheet pillar tube 9 is formed by joining sheet metal members 17, 17 having a U-shaped cross section so that their groove portions 17a face each other.

In the above case, each sheet metal member 17 is formed into a three-dimensionally bent shape by press working, and thereafter, by joining the sheet metal members 17 and 17 as described above, the end portion 9a is formed. There is.

An outward flange is provided at one end of each sheet metal member 17 described above.
17b is formed, and the outward flanges 17b are overlapped with each other and welded. Same as above, the other end side of each sheet metal member 17 is overlapped and welded in the direction inside and outside the end portion 9a.
The bracket 13 is formed by extending a part of each of the outward flanges 17b.

Further, a part of the end portion 9a in the longitudinal direction of each sheet pillar tube 9 is extended, and the extension piece
9b is a surface 1 where the left and right seat rails 11 and 11 face each other.
It is joined and welded to 1a and 11a.

(Effect of the Invention) According to the present invention, a pair of left and right first pipe members each having a rectangular cross section are provided, and end portions of the second pipe members are welded to each other in a butt shape at a middle portion in the longitudinal direction of each of these first pipe members. In this case, since a pair of sheet metal members having a U-shaped cross section are joined so that their groove portions face each other to form the end portion of the second pipe member, each sheet metal member is three-dimensionally bent. However, each of these sheet metal members can be easily formed by pressing, that is, the end portion of the second pipe material formed by joining the sheet metal members can also be easily formed.

Therefore, since the molding can be facilitated, the end portion of the second pipe material can be formed into a desired shape with high accuracy, and thus the appearance of the vehicle body frame is improved.

Further, the same as above, since a part of the end surface of the end portion in the longitudinal direction of the second pipe material is extended and the extending pieces are welded by joining the opposing surfaces of the left and right first pipe materials to each other. There is an effect.

That is, when the end portion of the second pipe material is to be butt-welded to the middle portion of the first pipe material in the longitudinal direction, the second pipe material
The abutted surface of the middle portion of the first pipe material, which is to be abutted with the end portions of the pipe material, is flat, and it is difficult to perform relative positioning of the both. However, since the extension piece is joined to the facing surface and welded as described above, the relative positioning of the both can be easily performed by the joining, and thus,
The body frame can be easily molded.

Furthermore, since the extension piece is extended as described above, the welding line at the joint between the midway portion of the first pipe material and the end portion of the second pipe material becomes longer by the amount of the extension, thus, The strength of the joint between the midway portion of the first pipe material and the end of the second pipe material is improved, and thus the strength of the vehicle body frame is improved.

Further, since the extension piece is integrally formed with the second pipe material, the reinforcement of the joint portion can be achieved with a simple configuration without increasing the number of parts.

Moreover, since the extension pieces are joined and welded to the mutually opposing surfaces of the left and right first pipe members, it is difficult for the extension pipes to be easily seen in appearance. Be done.

Therefore, the strength of the vehicle body frame can be improved with a simple structure and without deteriorating the appearance.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention, FIG. 1 is an overall side view, FIG. 2 is a view taken along the line II--II in FIG. 1, and FIG. 3 is a partially enlarged view of FIG. Is a sectional view taken along the line IV-IV of FIG. 3, FIG. 5 is a sectional view taken along the line VV of FIG. 3, and FIG. 6 is a sectional view taken along the line VI of FIG.
-VI line arrow view, FIG. 7 is a VII-VII line arrow view of FIG. 1 ... Body frame, 9 ... Seat pillar tube (second pipe material), 9a ... End portion, 9b ... Extension piece, 11 ... Seat rail (first pipe material), 11a ... Opposing surface, 17: Sheet metal member, 17a: Groove.

Claims (1)

[Claims] 1. A pair of left and right first pipe members having a rectangular cross section is provided, and a second pipe member having a rectangular cross section is provided extending in a direction substantially along a vertical virtual plane passing through the first pipe members. In a vehicle body frame structure of a vehicle such as a motorcycle in which the ends of the second pipe material are welded in a butt-welding manner in the middle of the longitudinal direction of the pipe material, a pair of sheet metal members having a U-shaped cross section have their groove portions facing each other. To form an end portion of the second pipe material, and part of the end surface of the end portion in the longitudinal direction of the second pipe material is extended, and the extension piece is divided into the left and right first portions. A vehicle body frame structure for a vehicle such as a motorcycle, characterized in that the pipe materials are joined and welded to opposite surfaces of each other.