JPH03118287A - Vehicle body frame structure of motorcycle - Google Patents

Abstract

PURPOSE:To improve welding workability by constructing a main frame or a sub frame out of approximately angular type taper pipe and welding the wide end parts of the taper and so forth to a head pipe to make a reinforcing plate at a joint part to a head pipe smaller or unnecessary. CONSTITUTION:In the vehicle body frame 1 of a motorcycle, a sub-frame 5 extending downward is welded to a head pipe 2, a main frame 6 is welded to the sub frame 5, and a couple of right and left sheet pillar tubes are welded to the rear end of the main frame 6, whereas the sub frame 5 and a main frame 6 are respectively constructed out of approximately angular type taper pipes where cylindrical raw pipes are formed with angular type cross section and one end side formed into a large width. Moreover, fitting work for making alignment to the axial direction of the head pipe 2 is performed on the wide end part 5a of the sub-frame 5, and the wide end part 5a is butted to the rear side of the head pipe 2 for welding. In addition, a reinforcing plate 20 is welded to the wide end part 5a of the sub frame 5 and the lower part of the head pipe 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a body frame structure for a motor vehicle that improves the joint strength between a head pipe and a main frame or subframe.

[Prior Art] For example, a main vibe is connected to a head pipe of a motorcycle so as to extend rearward, and a subframe is connected so as to extend downward.

This head pipe rotatably supports the front fork that suspends the front wheel, the engine is mounted on the main frame and subframe, and the main frame is further provided with a swingable rear arm that suspends the rear wheel. It is being

When looking at the state of load acting on the body frame of such a motorcycle, a concentrated load acts on the joints between the head pipe, the main frame, and the subframe. Therefore, for example, if the main frame or subframe is made of a round vibrator, it will not be possible to secure the joint strength with the head pipe, and it will be necessary to reinforce it with a reinforcing plate, and when joining these, welding lines is a curved line, and it is necessary to weld from the front side to the rear side of the head pipe, making the welding work cumbersome, difficult to automate, and increasing manufacturing costs.

In addition, there are some models in which the main frame and subframe are made of rectangular vibrators, but in this case, the welding line with the helad vibrator is straight, making welding easy and automation possible. A square frame is formed by forming split frames with a U-shaped cross section, and then welding the joints together to form a square frame.Welding is used to form the frame itself, so there are problems such as increased production costs. be.

[Problem to be solved by invention C] For this reason, a split frame that is split into two in the axial direction is formed by casting, and the split frames are joined and integrated by welding to form a main frame or subframe with a rectangular cross section. It is conceivable that the main frame and subframe can be formed using cast rectangular frames and welded to the head pipe, but if the main frame and subframe are made of cast rectangular frames, the strength of welding with the head pipe can be improved to some extent, but in the case of cast frames, the casting technology There is a problem in that the top wall thickness increases to a certain extent, impeding the weight reduction effect.

In addition, since the frame itself is a welded structure, material softening due to stress concentration at the weld bead and welding heat is unavoidable.
There are problems with poor strength and reliability, such as easy cracking. Further, there are problems in that the weight increases due to the weld bead and that productivity is low due to the need for welding work that requires relatively skill.

This invention was made in view of the above circumstances, and by using a substantially rectangular tapered pipe for the main frame or subframe, these frames can be made lighter and stronger, and the joint strength with the head pipe can be improved. The object of the present invention is to provide a motorcycle body frame structure that is easy to weld and suitable for automation.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the body frame structure of a motorcycle of the present invention is such that at least the main frame or the subframe to be welded to the head pipe is made of a cylindrical raw pipe with a rectangular cross section. The head pipe is made of a substantially rectangular tapered pipe formed into a shape that is wide and has a larger cross-sectional area toward one end, and the wide end of the substantially rectangular tapered pipe is welded to the head pipe. It is a feature.

The substantially rectangular tapered tube of the present invention can be manufactured, for example, by the following method. That is, the round vibrator is rotated and struck with a striking member in the direction perpendicular to its axis, and the protruding amount of the striking member is gradually changed by a so-called rotary swaging process to form a tapered round vibrator with a larger diameter toward the end. Further, it can be manufactured by inserting an inner mold of a predetermined shape into this vibrator and applying pressure from outside with an outer mold. In addition, the approximately rectangular tapered tube of the present invention includes those in which the wall is thicker toward the end, and those in which the side wall is curved so as to bulge outward. By forming the inner mold into a curved shape that bulges outward, the side wall can be curved outward.

[Function] In this invention, at least the main frame or the subframe to be welded to the head pipe is constituted by a substantially rectangular tapered pipe, and the wide end of this substantially rectangular tapered pipe is welded to the head pipe. The wide end of the substantially rectangular tapered pipe can be butt welded so as to substantially match the shape of the pipe.

Roughly speaking, by joining the wide end of a roughly rectangular tapered pipe to the head pipe, a large load is placed on the head pipe side, but the cross-sectional shape corresponds to the load, which is reasonable in terms of strength, and it is also possible to There is no problem of weight increase like in the case of manufactured products.

In addition, the substantially rectangular tapered tube has a structure in which, for example, a raw tube such as a round vibrator is compression-molded into a rectangular tapered shape, and the frame itself does not require welding work such as press molding, and its rigidity is also improved.

[Example] Hereinafter, an example of the present invention will be described in detail based on the accompanying drawings.

1 to 4 show a first embodiment of the present invention, and a first embodiment of the invention is shown in FIG.
The figure is a side view of the motorcycle, Figure 2 is a side view of the body frame, Figure 3 is a sectional view taken along line AA in Figure 2, and Figure 4 is a sectional view of another embodiment of the main frame and subframe. be.

In the figure, reference numeral 1 denotes a vehicle body frame, and a front fork 4 on which a front wheel 3 is suspended is rotatably supported by a head pipe 2 constituting the vehicle body frame 1. A sub-frame 5 extending downward is welded to the head pipe 2, a main frame 6 is welded to the sub-frame 5, a pair of left and right seat leaf tubes 7 are welded to the rear end of the main frame 6, and Rear arm brackets 9 are welded between a lower frame 8 and a seat frame tube 7, which are welded to the frame 5, and an engine 10 is mounted on these. A rear arm 12 on which a rear wheel 11 is suspended is connected to a pivot shaft 13 on a rear arm bracket 9.
This rear arm 12 is supported via a suspension system 14.
It can be swung by.

A pair of left and right seat rails 1 are provided at the rear end of the main frame 6.
5 is provided, and this seat rail 15 is connected to the support frame 1
A fuel tank 17 is provided on the main frame 6 so as to straddle the entire frame, and a seat 18 is placed on the seat rail 15 from the fuel tank 17.

Also, there is a side stand below the rear arm bracket 9! 9 is provided.

Head pipe 2, sub frame 5 and main frame 6
is constructed as shown in FIGS. 2 and 3. That is, the main frame 6 and the sub-frame 5 are each made of a substantially rectangular tapered pipe formed by forming a cylindrical raw pipe into a shape with a rectangular cross section and a shape in which the width increases toward the #4 side and the cross-sectional area increases. It is configured. The sub-frame 5 made of a substantially rectangular tapered pipe has a wide end 5a and a narrow end 5d, and is processed to align the long axis direction of the wide end 5a with the axial direction of the head pipe 2. This wide end portion 5a
is welded against the rear side of the head pipe 2. The wide end 5a of this subframe 5 and the head pipe 2
A reinforcing plate 20 is welded to the lower part of the steering wheel, and a steering stopper 21 is welded to this reinforcing plate 20.

The main frame 6, which is made of a substantially rectangular tapered tube, has a wide end 6a and a narrow end 6d, and the long axis direction of the wide end 6a is aligned with the axial direction of the subframe 5. The wide end portion 5a of the subframe 5 is welded against the upper portion 5b of the wide end portion 5a. A reinforcing plate 22 is welded between the main frame 6 and the subframe 5. By welding the main frame 6 and the sub-frame 5, as shown in FIG. The length becomes longer and the strength improves.

In this way, the subframe 5 made up of approximately rectangular tapered tubes
Since the wide end 5a of is welded to the head pipe 2,
It can be welded to approximately match the shape of the head pipe. Therefore, the reinforcing plate 20 at the joint with the head pipe 2 can be made as small as possible, and the welding length of the reinforcing plate 20 will not become longer than necessary. Furthermore, it becomes possible to straighten the welding line and eliminate welding to the back side of the head pipe 2, making it possible to automate welding.

By configuring the subframe 5 and main frame 6 with straight-sided, approximately rectangular tapered pipes, a large load is applied to the subframe 5 and main frame 6, but the cross-sectional shape corresponds to the load, which is reasonable in terms of strength. It is. In addition, a substantially rectangular tapered tube has a structure in which a raw tube such as a round vibrator is molded into a square tapered shape, and a square frame is created by joining a pair of press-formed frames with a U-shaped cross section. No welding work is required compared to those that form

Therefore, the problem of stress concentration and softening of the material due to weld beads does not occur, and reliability in terms of strength can be improved, and
Improve productivity.

The substantially rectangular tapered tubes constituting the subframe 5 and main frame 6 shown in FIG. It is bent to match the shape of 5.

5 to 7 show a second embodiment, in which the subframe 5 is welded to the head pipe 2 as in the first embodiment, but the wide end 6a of the main frame 6 is attached to the subframe. 5 is overlapped with the upper part 5b of the wide end 5a, and this overlapped portion 23 is welded.By overlapping, the safety of welding is improved and the strength is also improved.

Further, the main frame 6 and the subframe 5 can have shapes similar to those shown in FIG. 4 above.

8 and 9 show a third embodiment, in which the subframe 5 is welded to the head pipe 2 as in the first embodiment, but the lower wide end 6a of the main frame 6 A notch 6b is formed in the notch 6b, and the upper part 5b of the sub-frame 5 is inserted into the notch 6b and overlapped to cover it.

Then, the wide end portion 6a of the main frame 6 is brought into contact with the head pipe 2 and welded, and the periphery of the overlapping portion 24 of the subframe 5 and the main frame 6 is also welded. In this way, since both the subframe 5 and the main frame 6 are welded to the head pipe 2, the joint strength is high.Furthermore, the main frame 6 and subframe 5 behind the head pipe 2 are made of two layers, which increases rigidity. It's getting expensive.

10 and 11 show a fourth embodiment, in which the subframe 5 is welded to the head pipe 2 as in the first embodiment, but the wide end 6a of the main frame 6 is connected to the subframe 5. 5 are overlapped so as to cover the entire wide end portion 5a. Then, the wide end portion 6a of the main frame 6
is abutted against the head pipe 2 and the reinforcing plate 20 and welded, and furthermore, the periphery of the overlapping portion 24 with the subframe 5 is also welded. In this way, the wide end 6a of the main frame 6
are welded to the head pipe 2, the wide end 5a of the subframe 5, and the reinforcing plate 20, and the wide end 5a of the subframe 5 is
Since it covers the entire surface, the joint strength is even higher and the rigidity is also higher.

12 and 13 show a fifth embodiment, in which the wide end 6a of the main frame 6 is abutted against the head pipe 2 and welded, and the wide end 6a of the main frame 6 is welded from below. The wide end portion 5a of the subframe 5 is inserted so as to cover the head pipe 2, and the wide end portion 5a of the subframe 5 is welded to the head pipe 2, and the overlapping portion 24 of the subframe 5 and the main frame 6 is also Welding.

Further, the wide end portion 5a of the subframe 5 is covered from below with a reinforcing plate 20, and the reinforcing plate 20, the head pipe 2, and the wide end portion 5a of the subframe 5 are welded together.

Figures 14 to 16 are '! J6 example is shown,
The wide end 6a of the main frame 6 is welded against the head pipe 2, and the wide end 5a of the subframe 5 is welded to the head pipe 2.
a to the head pipe 2 and the wide end 6 of the main frame 6
It is welded against the lower part 6C of a. Furthermore, this sub-frame 6 is covered with a reinforcing plate 20 from below, and the reinforcing plate 20 is
0, the head pipe 2 and the subframe 6 are welded together.

Moreover, the subframe 5 and the main frame 6 are the 16th
As shown in the figure, the shape can be similar to that shown in FIG. 4 of the first embodiment.

17 to 19 show a seventh embodiment, in which the wide end 6a of the main frame 6 is abutted against the head pipe 2 and welded, and the wide end 5a of the subframe 5 is welded to the head pipe 2. This overlapping portion 25 is overlapped with the lower part 6C of the wide end portion 6a and welded, and a part thereof is abutted against the head pipe 2 and welded. Further, the subframe 5 and the main frame 6 can have the same shape as shown in FIG. 4 of the first embodiment, as shown in FIG. 19.

20 to 22 show an embodiment applied to a starter type motorcycle.

The wide end 31a of the main frame 31 is abutted against and welded to approximately the lower half of the head pipe 30, and the main frame 31 extends downward from the head pipe 30 and is bent downward to form a floor and extends toward the rear of the vehicle body. It extends towards. The Hera Vib side of this main frame 31 is the second
As shown in Fig. 1, the cross section is formed into a square shape, and the central part
The cross-sectional shape is changed at b, and the rear end portion 31c is constituted by a round tapered tube as shown in FIG. Further, the wide end portion 31a of the main frame 31 is located at the 23rd wide end portion 31a.
As shown in the figure, it can be formed into a substantially oval shape.

Further, the arm portion 19a of the side stand 19 shown in FIG. It can be constructed with a tapered tube of any shape.

As shown in FIG. 24, a side stand 190 for a large motorcycle is constructed by welding a vehicle body side mounting member 192 to the wide end 191a of an arm portion 191 made of a tapered tube, and welding a grounding member 193 to the narrow end 191b. A footrest member 194 is welded to the lower side.

As shown in FIG. 25, a side stand 290 for a small motorcycle is constructed of a tapered tube, and the wide ends 291a of the arm portion 291 are cut out oppositely, and the remaining portion of the cutout is used for mounting on the vehicle body side. The portion 292 is integrally formed, and the end portion of the narrow end portion 291b is pressed to form a crushing grounding portion 293.

In this way, configuring the side stand with a tapered tube has advantages such as a better balance of strength and lighter weight compared to conventional round pipes or tapered tubes formed by casting. ing.

[Effects of the Invention] As described above, this invention comprises at least the main frame or sub-frame welded to the head pipe by a substantially rectangular tapered tube, and the wide end of this substantially rectangular tapered tube is welded to the head pipe. Therefore, the wide end of the substantially rectangular tapered pipe can be butted and welded so as to substantially match the shape of the head pipe. Therefore, the reinforcing plates at the joint with the head pipe are made as small as possible, fewer or unnecessary, and the welding length of these reinforcing plates does not become longer than necessary. In addition, the welding line can be made straight, and welding to the back side of the head pipe is no longer required, making it possible to automate welding.

Furthermore, by joining the wide end of the substantially rectangular tapered pipe to the head pipe, a large load is applied to the head pipe, but the cross-sectional shape corresponds to the load, which is reasonable in terms of strength.

In addition, the approximately rectangular tapered tube has a structure in which, for example, a raw tube such as a round vibrator is compression molded into a rectangular tapered shape, and the molding of the frame itself does not require welding like press molding, and there is no weld bead. There is no problem of material softening caused by stress concentration, which improves reliability in terms of strength and improves productivity.

[Brief explanation of drawings]

1 to 4 show a first embodiment of the present invention, and a first embodiment of the invention is shown in FIG.
The figure is a side view of the motorcycle, Figure 2 is a side view of the body frame, Figure 3 is a sectional view taken along line AA in Figure 2, and Figure 4 is a sectional view of another embodiment of the main frame and subframe. 5 to 7 show the second embodiment, FIG. 5 is a side view of the vehicle body frame, FIG. 6 is a sectional view taken along line BB in FIG. 5, and FIG. 8th cross-sectional view of the embodiment of
9 and 9 show the third embodiment, FIG. 8 is a side view of the vehicle body frame, FIG. 9 is a sectional view taken along the line CC in FIG. 8, and FIGS. Fig. 10 is a side view of the vehicle body frame, Fig. 11 is a sectional view taken along line DD in Fig. 10,
12 and 13 show the fifth embodiment, FIG. 12 is a side view of the vehicle body frame, FIG. 13 is a sectional view taken along line E-E in FIG. 12, and FIGS. 14 to 16 are the sixth embodiment. For example, the first
Figure 4 is a side view of the vehicle body frame, Figure 15 is F in Figure 14.
-F sectional view, FIG. 16 is a sectional view of another embodiment of the main frame and subframe, FIGS. 17 to 19 show the seventh embodiment, and FIG. 17 is a side view of the body frame, and FIG.
The figure shows a G-C sectional view in Fig. 17, Fig. 19 is a sectional view of another embodiment of the main frame and subframe, and Figs. 20 to 23 show an embodiment applied to a starter type motorcycle. , FIG. 20 is a side view of the vehicle body frame, FIG. 21 is a sectional view taken along line HH in FIG. 20, and FIG. 22 is a 1--
1, FIG. 23 is a sectional view of another embodiment of the main frame, FIG. 24 is a perspective view of a side stand for a large-sized motorcycle, and FIG. 25 is a perspective view of a side stand for a small-sized motorcycle. In the figure, 1 is the body frame, 2.30 is the head pipe, 5 is the subframe, 6°31 is the main frame, and 5a. 6a is a wide end, and d and 6d are narrow ends. Patent applicant Yamaha Motor Co., Ltd.

Claims (1)

[Claims] At least the main frame or subframe to be welded to the head pipe is made of a substantially rectangular tapered pipe formed by forming a cylindrical raw pipe into a shape in which the cross section is approximately rectangular, and the cross section becomes wider toward one end. A body frame structure for a motorcycle, characterized in that a wide end portion of the approximately rectangular tapered tube is welded to the head pipe.