JPH08282565A - Frame structure of motor-bicycle - Google Patents

Abstract

PURPOSE: To provide the frame of a motor bicycle in which the assembly and the welding of the outer and the inner of a tank rail can be carried out simply, and the welding distortion of the tank rail can be reduced. CONSTITUTION: The end edge 13a of the joint peripheral edge 13 of an inner 72 to be the composing member of a tank rail 7 in a twin tube frame 1A is bent to the inner side of the tank rail 7, while the lower side joint peripheral edge 151 of the outer 71 to be the other composing member of the tank rail 7 is extended to the position facing the inner side end edge 9a1 of a vehicle at the joint surface with the lower side contact surface 73 of the tank rail of an engine mounting bracket 9. And the inner side end edge 9a1 of the vehicle and the outer side end edge 9a2 of the vehicle are welded with the lower side joint peripheral edge 131 of the inner 72 and the lower side joint peripheral edge 151 of the outer 71 respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motorcycle frame.

[0002]

2. Description of the Related Art Among motorcycle frames, there is a so-called twin tube frame. 2 and 3
1 shows an example of the twin tube frame 1, and shows a left side surface and a partially omitted plane of the twin tube frame 1, respectively. Twin tube frame 1
Is the head pipe 3 located at the upper part of the vehicle and the pivot plates 5 and 5 respectively arranged at the lower left and right sides of the vehicle.
(Only the one on the left side is shown) and a tank rail 7 connecting the head pipe 3 and each pivot plate 5 are provided.

As shown in FIG. 2, the tank rail 7 has such a shape that it is linearly connected to the head pipe 3 and the pivot plate 5 when viewed from the side, and as shown in FIG. It is almost U-shaped when viewed from the plane (or bottom). Then, positioned below the head pipe 3, the position of the lower surface 7 ₃ of the tank rails 7, engine mounting brackets 9 for suspending the engine (not shown) (hereinafter, will be described and explained later in terms of this prior art embodiment In the example section, simply referred to as "bracket 9").

[0004] More specifically, as can be seen from Figure 4, which schematically illustrates a cross section as viewed from the arrow direction along a plane including the line IV-IV in FIG. 3, the tank rails 7, the outer ₇₁ is the component The inner 7 ₂ and the inner skin of the Japanese confectionery are welded together by a so-called middle structure, and the lower surface 7 of the tank rail 7 is formed in this way.
_After applying the joint surface 9a of the bracket 9 to ₃ , the both 7 and 9 are integrated by welding.

By the way, as shown in FIG. 5, the inner dimension d ₁ of the outer 7 ₁ of the tank rail 7 in the height direction and the outer dimension d ₂ of the inner 7 ₂ of the tank rail 7 in the height direction.
With respect to the tolerance, the larger the tolerance, the easier the fitting of the two, but the larger the clearance c, the more difficult the welding. On the contrary, as shown in FIG. 6, if the tolerance is made small, the welding becomes easy, but the clearance c becomes small, so that the fitting is difficult.

Further, as shown in FIG. 4, the welded portions W ₁ , W ₂ , ... Between the outer 7 ₁ and the inner 7 ₂ are raised by the bead, and particularly, the lower welded portion at the center of the tank rail lower surface 7 _3. In W ₁ , this interferes with the fact that the bracket 9 cannot be brought into close contact with the lower surface 7 ₃ of the tank rail 7. For this reason, the so-called sitting of the bracket 9 is not good.

Therefore, the recess 9 (weld bead escape) 11 including the lower welding portion W ₁ is provided in the joint surface 9a of the bracket 9 with the lower surface 7 ₃ of the tank rail. It was troublesome to assemble because it was necessary.

In addition to the above-mentioned welded portion W ₁ , as shown in FIG. 4, the welded portions include welded portions W ₂ · W ₃ on the left and right edges of the bracket 9 and the outer 7 ₁ and the inner 7 ₂ . There is an upper weld location W ₄ .

By the way, generally, if there are many welded spots, welding strain will occur. Therefore, in order to reduce welding strain, it has been desired to provide a new technique that requires welding at as few places as possible.

[0010]

SUMMARY OF THE INVENTION The present invention has been invented in view of the above circumstances, and the problem to be solved is to easily assemble and weld the outer and inner of the tank rail. At the same time, it is to provide a motorcycle frame that can reduce the number of tank rail welds.

[0011]

A frame of a motorcycle according to the present invention solves the above problems and is as follows. That is, the frame structure of the motorcycle of the present invention according to claim 1 has a shape in which the head pipe and the pivot plate are linearly connected by a tank rail when viewed from the side of the vehicle, and A twin tube in which an outer member located outside the vehicle and an inner member located inside the vehicle, which are constituent members of the tank rail, are integrated by a middle structure in which the joint peripheral portion of the inner is fitted in the joint peripheral portion of the outer. The present invention relates to a frame, characterized in that an edge of a joining peripheral edge portion of the inner is curved toward an inner side of the tank rail.

The frame structure for a motorcycle according to the present invention as defined in claim 2 has a shape in which the head pipe and the pivot plate are linearly connected by a tank rail when viewed from the side of the vehicle. The outer member located on the outside of the vehicle, which is a component of the tank rail, and the inner located on the inside of the vehicle are integrated by a middle structure in which the joining peripheral portion of the inner is fitted into the joining peripheral portion of the outer, In a twin tube frame in which an engine suspension bracket or a reinforcing member is attached to the lower surface of the tank rail thus formed, at least a part of the joint peripheral edge portion of the outer is attached to the tank of the engine suspension bracket or the reinforcing member. The extension is extended to the extent that it faces the inner edge of the vehicle at the joint surface with the bottom surface of the rail. The lower surface of the tank rails above,
The vehicle inner edge of the engine suspension bracket or the reinforcing member attached to the lower surface of the tank rail is welded to the inner joint peripheral edge portion, and the vehicle outer edge is welded to the outer joint peripheral edge portion. It is characterized by

[0013]

Therefore, according to the present invention as set forth in claim 1, since the edge of the joint peripheral edge portion of the inner is curved toward the inner side of the tank rail, the curved edge in the height direction of the inner. And the outer dimensions of the other portion of the joining peripheral edge portion not including the edge, the outer dimension of the edge is smaller. Therefore, in order to facilitate welding of the outer and the inner, the inner dimension in the height direction of the outer and the outer dimension in the height direction of the inner, that is, the edge of the joint peripheral portion in the height direction of the inner Even when the intersection with the external dimensions related to other portions not included is set to be small in advance, the external dimensions of the curved edge in the height direction of the inner part and the other of the joining peripheral edge portions not including the edge. Since the outer dimension of the part is smaller than the outer dimension of the part, immediately after the start of fitting the inner to the outer, there is a gap due to the difference between the inner dimension of the outer and the outer dimension of the inner edge. Since it becomes large, the substantial intersection of the inner and outer portions immediately after the start of fitting becomes large, so that fitting of the both becomes easy.

According to the second aspect of the present invention, at least a part of the outer peripheral joint edge portion is exposed to the inner edge of the vehicle at the joint surface of the engine suspension bracket or the reinforcing member with the lower surface of the tank rail. By extending to
Since the extension is substantially the lower surface of the tank rail, at least the center of the lower surface of the tank rail is not welded to join the inner and outer. Therefore, the lower surface of the tank rail to which the engine mounting bracket or the reinforcing member is attached is flat, and therefore, the engine mounting bracket or the reinforcing member can be attached to the lower surface of the tank rail in a close contact state.

Further, the vehicle inner edge of the engine suspension bracket or the reinforcing member attached to the lower surface of the tank rail is welded to the inner joint peripheral edge portion, and the vehicle outer edge is welded to the outer joint peripheral edge portion. Therefore, the inner and outer joints on the lower surface of the tank rail are indirectly joined by interposing an engine mounting bracket or a reinforcing member between them, and cannot be made directly. No welding is required to join the inner and outer parts at the center of the lower surface.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A twin tube frame 1 adopting a frame structure A of a motorcycle of the present invention will be described below with reference to the drawings.
A will be described in detail according to the illustrated embodiment. The twin tube frame 1A is different from the twin tube frame 1 described in the section of the prior art only in the joint structure of the outer 7 ₁ , the inner 7 ₂ and the bracket 9 (or the reinforcing member). Only different parts will be described, the same parts will be denoted by the same reference numerals, and description thereof will be omitted.

[0017] As can be seen from Figure 1 that shows a cross section corresponding to FIG. 4 described in the prior art section, the edge 13a of the inner 7 ₂ of bonding perimeter 13 is curved toward the inside of the tank rails 7 The cross section is J-shaped.

Further, of the joint peripheral edge portion 15 of the outer 7 ₁ , at least the lower joint peripheral edge portion 15 ₁ as a portion to which the bracket 9 is attached is the joint surface 9 of the bracket 9.
It is extended so as to face the inner edge 9a ₁ of the vehicle at a. Therefore, the lower joining peripheral edge portion 15 ₁ becomes substantially the lower surface 7 ₃ of the tank rail 7.

Then, at least the vehicle inner side edge 9a ₁ of the bracket 9 attached to the lower surface 7 ₃ (15 ₁ ) of the tank rail is a lower joint peripheral edge 13 ₁ which is a part of the joint peripheral edge 13 of the inner 7 _2. and the base 14 of the welding, also the lower bonding perimeter 15 ₁ of the vehicle outer edge 9a ₂ outer 7 ₁
It is adapted to be welded to the base 16 of the. However, in this embodiment, the base 1 of the lower joining peripheral edge 13 ₁ of the inner 7 ₂ is
4 and the edge 15a of the lower joining peripheral edge portion 15 ₁ of the outer 7 _1.
And the vehicle inner edge 9a _{1 of} the bracket 9 are simultaneously welded at three points.

[0020] Thus, in the thus constituted twin-tube frame 1A, since is curved edge 13a of the inner 7 ₂ of bonding perimeter 13 toward the inside of the tank rails 7, the inner 7 ₂ The outer dimension d _{3 of the} curved end edge 13a in the height direction and the outer dimension d ₄ of the other portion of the joining peripheral edge portion 13 (substantially this d ₄ is the maximum outer dimension of the inner 7 _{2 in} the height direction). , D ₃ is smaller.

[0021] Thus, to facilitate welding the inner 7 ₂ to the outer _71, d is (drawing even if that had been taken in advance smaller the intersection of the inner dimension d ₁ and the d ₄ in height direction of the outer 7 ₁ the ₁ and d ₄ are indicated by the same dimension line.), and the d _3, in the d _4, since who d ₃ is small, immediately after the start fitting to the outer 7 ₁ of the inner 7 _2, the inner dimensions of the outer 7 ₁ d ₁ and the inner 7
_{Since the} clearance c (see FIG. 5 or FIG. 6) due to the difference in the outer dimension d ₃ related to the edge of ₂ becomes large, the substantial intersection between the inner 7 ₂ and the outer 7 ₁ becomes large immediately after the start of fitting, and It becomes easy to fit both. Therefore, it is possible to simplify the assembly and welding of the outer 7 ₁ and the inner 7 ₂ tank rails 7.

Further, by bending the end edge 13a toward the inside of the tank rail 7, the portion functions as a rib, and the rigidity of the tank rail 7 is enhanced.

Furthermore, the lower bonding perimeter 1 of the outer 7 ₁
Since 5 ₁ is extended to reach the vehicle inner end edge 9a ₁ of the joint surface 9a of the bracket 9, the lower joint peripheral edge portion 15 ₁ becomes the lower surface 7 _{3 of the} tank rail 7, so at least the tank rail At the center of the lower surface 7 ₃ , welding for joining the inner 7 ₂ and the outer 7 ₁ is not performed. Thus, the tank rail lower surface 7 ₃ attached with brackets 9 becomes flat, therefore, it is possible to improve its sat tank rail lower surface 7 ₃ attach the bracket 9 in a close contact state, assembly can be simplified.

Then, the vehicle inner edge 9a ₁ of the bracket 9 attached to the lower surface 7 ₃ of the tank rail is attached to the inner 7 ₂
Since it is configured to be welded to the base portion 14 of the lower joint peripheral edge portion 13 ₁ and the vehicle outer edge 9a ₂ is welded to the base portion 16 of the lower joint peripheral edge portion 15 ₁ of the outer 7 ₁ , the tank rail lower surface The inner 7 ₂ and the outer 7 ₁ are joined to each other on the 7 ₃ side indirectly by interposing the bracket 9 between the inner 7 ₂ and the outer 7 _1, and are not directly joined. Therefore, the tank rail lower surface 7
_{3 No} welding is required to join the inner 7 ₂ and the outer 7 ₁ at the center.

Therefore, the twin tube frame 1A
As shown in FIG. 1, the tank rail 7 according to
The welding points are the welding points W ₂ and W ₃ related to the left and right side edges of the bracket 9 and the upper welding point W ₄ between the outer 7 ₁ and the inner 7 _2, and the welding points W described in the prior art. _{Since 1} is no longer necessary, the number of welded parts is reduced, and welding distortion of the tank rail 7 can be suppressed. Further, since the number of welded parts is reduced, the beads are not attached so much, so that weight reduction and cost reduction can be expected.

[0026] In this embodiment, although the lower surface 7 ₃ of the tank rails 7 by extending the lower bonding perimeter 15 ₁ mounted the bracket 9 of the bonding perimeter 15 of the outer 7 _1, inner 7 The same action and effect can be obtained by extending the lower joining peripheral edge portion 13 ₁ on the bracket 9 side of the _second joining peripheral edge portion 13 and forming this as the tank rail lower surface.

[0027]

According to the present invention as set forth in claim 1, the outer dimension of the curved edge in the height direction of the inner and the outer dimension of the portion other than the edge are related to the outer edge. Since the front of the dimension is smaller than the outer dimension of the portion other than the edge, fitting of the inner with the outer becomes easier. Therefore, it is possible to easily assemble and weld the outer and inner of the tank rail. Also,
According to the second aspect of the present invention, at least at the center of the lower surface of the tank rail, welding for joining the inner and outer portions is not performed. Therefore, the lower surface of the tank rail to which the engine mounting bracket or the reinforcing member is attached becomes flat, and the engine mounting bracket or the reinforcing member can be attached in close contact with the lower surface of the tank rail. Therefore, the assembling can be done that much. Furthermore, the inner and outer joints on the bottom side of the tank rail are
Since it is indirectly performed by interposing an engine mounting bracket or a reinforcing member between them and not directly performed, the welding for joining the inner and the outer at the center of the lower surface of the tank rail is also unnecessary. Therefore, the welding for joining the inner and outer parts on the lower surface side of the tank rail, which is conventionally required, becomes unnecessary. Therefore, since the number of welded portions is reduced accordingly, the welding strain of the tank rail can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a twin tube frame adopting a frame structure of a motorcycle of the present invention, and is a view corresponding to FIG. 4.

FIG. 2 is a left side view of a conventional twin tube frame.

FIG. 3 is a plan view with a part of FIG. 2 omitted.

FIG. 4 is a schematic cross section taken along a plane including line IV-IV in FIG. 3 and seen from the direction of the arrow, showing a problem of the prior art.

FIG. 5 is a diagram showing another problem of the conventional technique.

FIG. 6 is a diagram showing a problem when the condition is different from that of FIG.

[Explanation of symbols]

A Motorcycle frame structure 1A Twin tube frame 3 Head pipe 5 Pivot plate 7 Tank rail 7 ₁ Outer 7 ₂ Inner 7 ₃ Tank rail lower surface 9 Engine mounting bracket or reinforcing member 9a Engine mounting bracket or reinforcing member tank rail lower surface Joining surface 9a ₁ Vehicle inner edge (of engine mounting bracket or reinforcing member) 9a ₂ Vehicle outer edge (〃) 13 Inner joining peripheral edge 13a Inner joining peripheral edge 15 Outer joining edge 15 ₁ Outer Part of the bonding edge of

Claims (2)

[Claims] 1. When viewed from the side of the vehicle, the head pipe and the pivot plate are linearly connected by a tank rail, and are located outside the vehicle, which is a constituent member of the tank rail. In a twin tube frame in which an outer and an inner located inside the vehicle are integrated by a middle structure in which the joint peripheral edge of the inner is fitted into the joint peripheral edge of the outer, an edge of the inner peripheral joint edge is formed. A frame structure for a motorcycle, characterized in that the inside of the tank rail is curved. 2. When viewed from the side of the vehicle, the head pipe and the pivot plate are linearly connected by a tank rail, and are located outside the vehicle, which is a constituent member of the tank rail. The outer and the inner located inside the vehicle are integrated by a middle structure in which the joint peripheral edge of the inner is fitted in the joint peripheral edge of the outer, and the engine suspension is formed on the lower surface of the tank rail thus formed. In a twin-tube frame to which a bracket or a reinforcing member is attached, at least a part of a joint peripheral edge portion of the outer is exposed to an inner edge of a vehicle at a joint surface of the engine suspension bracket or the reinforcing member with the lower surface of the tank rail. By extending it to the extent that it becomes the bottom surface of the tank rail substantially,
The vehicle inner edge of the engine suspension bracket or the reinforcing member attached to the lower surface of the tank rail is welded to the inner joint peripheral edge portion, and the vehicle outer edge is welded to the outer joint peripheral edge portion. The frame structure of the motorcycle, which is characterized by that.