JPS62114790A - Coupling structure of square pipe - Google Patents

Abstract

PURPOSE:To easily form a weld zone and to form a joint part having excellent weldability and appearance by providing a tongue part to the end of a square pipe, and bending the other side wall inward toward said part thereby forming a joint side wall. CONSTITUTION:The end of the square pipe 1 is pressed by using a punch 2 to form the tongue part 1e. The pipe 1 is then rotated 90 deg. to bring the side wall 1c upward and thereafter the pipe is pressed by a punch 3. The side wall 1c is bent inward around the tongue part 1e by such pressing, by which the joint side wall 1f is formed. The joint side wall 1f and cutting face 1h are pressed to the side walls 5a, 5b of the other square pipe 5 and the contact edges are welded 6. The weld zone is, therefore, easily formed by pressing and the joint part having the excellent weldability and appearance is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of application in the fL industry) The present invention relates to a connection structure for square pipes in which square pipes having a square cross section are joined together by welding.

(Prior Art) Various joining structures have been adopted in the past in which pipe materials are joined by welding. For example, as disclosed in Japanese Utility Model Publication No. 56-48631, the tip of a round pipe is crushed by press working. There is a type that forms a flat welded part and joins it to the side wall of a square pipe by welding.

By the way, when joining square pipes with a square cross section, 1. For example, use a cutting machine to cut the end of the square pipe at an acute angle according to the joining direction with the side wall of the other square pipe, and then attach this cut part to the side wall of the other square pipe. It is butted against the side wall of a square pipe,
Pressing the end of a square pipe to form a weld is not performed.

(Problem to be solved by the invention) It is easy to form a welded part by pressing the end of a square pipe in this way, but since the cross section is square, special consideration is required unlike a round pipe. Is it necessary to do it and form it?

In particular, when forming welds on square pipes by press working, straightness of the bent part is required, and this straightness of the bent part allows for close welding, making welding easier and improving weld strength. A good appearance can be obtained.

This invention was made against the background of this situation, and it is possible to bend the welded part of a square pipe with a simple structure without using a metal core, etc., to obtain straightness, to facilitate welding, and to improve welding strength. Another purpose is to provide a joint structure for square pipes with excellent appearance.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a square pipe in which the end of a square pipe with a square cross section is joined to the side wall of another square pipe with a square cross section by welding. In the joint structure, a notch is provided in one side wall of the end of the rectangular pipe in an arbitrary axial direction and a notch along the corner to form a tongue, and this tongue is bent toward the opposite side wall. The other side wall cut along the corner is bent inward using the tongue as a core material to form a joint side wall, and the cut surface of this joint side wall and the first side wall includes the corner of the other square pipe. It is characterized by back welding to the two side walls.

(Function) In this invention, a tongue portion formed on one side wall is bent and inclined at the welded portion of a square pipe, and the other side wall is bent and overlapped with this tongue portion as a core material. As a result, a joint side wall is formed, and good straightness is obtained at the bent part, and when this joint side wall and the cut surface of the side wall are brought into contact with the two side walls including the corner of the other rectangular pipe, they will come into close contact. Can be joined. Therefore, welding is easy, welding strength is improved, and a good appearance can be obtained.

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

1 to 6 show the process of forming a welded portion of a rectangular pipe with a rectangular cross section to be welded.

First, in FIG. 1, a hollow square pipe 1 with a square cross section is prepared, and this square pipe 1 has side walls la, lb, l.
c, ld exist. The rectangular pipe 1 is made of iron, aluminum (including aluminum alloy), magnesium (including magnesium alloy), or the like.

Next, as shown in FIG. 2, a bunch 2 is placed at a predetermined position at the end of this rectangular pipe 1, and the bottom surface 2b of the pressing portion 2a of this bunch 2 is inclined. Furthermore, the width of the pressing part 2a is formed so that the tip end thereof has the same width as the inner diameter of the rectangular pipe 1, one side wall 2c is formed to be inclined, and the other side wall 2d is formed to be straight.

As shown in FIG. 3, this bunch 2 presses the side wall 1a of the rectangular pipe 1 by applying its pressing portion 2a thereto.

As a result, the straight side wall 2d of the pressing part 2a cuts the end of the side wall 1a of the square pipe in the pipe axial direction, and the roughly inclined side wall 2c of the pressing part 2a cuts the end of the side wall 1a of the square pipe 1 inward. Tilt and cut in the axial direction of the pipe in the same way. A tongue portion 1e is formed by this cutting, and this tongue portion 1e is pressed by the inclined surface 2b of the pressing portion 2a of the bunch 2 and bent inward.

Next, the side wall IC facing the tongue portion 1e of the rectangular pipe 1 is turned upward as shown in FIG. 4, and is pressed by a bunch 3 having a relief portion 3a at the end. As shown in FIG. 5, the pressing force of the bunch 3 causes the side wall IC to be bent inward using the tongue portion 1e as a core material to form a joined side wall 1f.

This joining side wall 1f overlaps the tongue portion 1e, and the bent portion 1g of the side wall becomes straight. As a result, as shown in FIG. 6, the welded portion 4 of the square pipe 1 consists of two right-angled side walls lb and ld that remain at the end of the square pipe 1, and a tongue portion that is bent inward by cutting the side wall 1a. 1e, and a joint side wall 1f which is folded over with the tongue portion 1e as a core material.

The welded portion 4 of this square pipe 1 is easily formed by a two-step press process, and the joining direction of one square pipe 1 and the other square pipe is between the joint side wall if and the cut surface 1h formed on the side wall 1a. It is determined arbitrarily depending on the inclination angle.

7 to 10 show the square pipe 1 welded to the other square pipe 5. FIG.

The welded part 4 of the square pipe 1 is connected by applying the cut surface 1h of the side wall 1f and the side wall 1a to the side walls 5a, 5b of the other square pipe 5, and joining the side wall 1a of one square pipe 1 and the other along the contact edge. The side wall 5a of the rectangular pipe 5 is welded 6 with the contact edge remaining.

As shown in FIGS. 7 and 8, the rectangular pipe 1 is joined to a rectangular pipe 5 arranged in parallel at a predetermined angle in a three-dimensional direction. The inclination angle α in the left-right direction is determined by the inclination angle of the connecting surface 1h formed on the side wall 1a of the rectangular pipe 1. Also, the vertical inclination angle β
is determined by the inclination angle of the joining side wall 1f formed on the side wall 1c of one square pipe 1.

As shown in FIGS. 9 and 10, in the welded portion 4 of the square pipe 1, the joint side wall 1f is connected to the side wall 5a of the square pipe 5.
The bent portion 1g is welded to the side wall 5a of the other rectangular pipe 5. In this welding 6, since the bent portion 1g is formed in a straight line, welding is easily and reliably performed, and by welding up to the bent portion 1g, the weld length is expanded and the weld is strengthened.

During this welding, the heat capacity between the welded part 4 of the square pipe 1 and the side wall of the other square pipe 5 can be reduced by providing the tongue part 1e and the joining side wall 1f in the welded part 4 of the square pipe 1. The temperature rise is equalized between the welded part 4 and the side wall of the other rectangular pipe 5, the concentration of welding heat is reduced, and welding becomes easier.

11 to 16 show the process of forming another welded portion of the rectangular pipe 1 to be welded.

In this embodiment, the width of the pressing portion 2a of the bunch 2 is the same as the width of the inner diameter of the rectangular pipe 1 having a rectangular cross section. Therefore, as shown in FIG. 13, cuts in the side wall 1a of the rectangular pipe 1 are formed in the axial direction of the pipe, leaving the thickness of the side walls 1b and 1c at both corners, and the cut tongue 1e is bent inward. be done.

As shown in FIGS. 14 and 15, when one of the side walls 1b, lc is pressed from above with the pressing portion 3a of the punch 3, it is bent inward using the tongue portion 1e as a core material. Due to the stiffness, a joint side wall 1f is formed so as to overlap the tongue portion 1e, as shown in FIG. 16.

Figures 17 to 20 show this square pipe welded to the side wall of the other square pipe.

The square pipe 1 formed in FIGS. 11 to 16 is formed by cutting its tongue 1e or side wall 1a parallel to the pipe axis direction, so that the other square pipe 5 can be cut directly inside the side wall 1b. It is joined to the side wall 5b. Therefore, as shown in FIGS. 17 and 20, the square pipe 1 and the other square pipe 5 are joined in parallel.

FIGS. 21 and 22 show an embodiment in which the present invention is applied to a body frame of a motorcycle.

The body frame 11 includes a head pipe 12, a pair of main frames 13, a town tube 14, and a rear bracket 15.
, a sea rail 16 and a hack stay 17. The main frame 13, rear bracket 15, seat rail 16, and back stay 17 are each formed from square pipes. A pair of main frames 13 extend rearward from the head pipe 12, and are fixed to the main frames 13 by welding the surface ends of the seat rail 6. An upper end portion of a back stay 17 whose lower end portion is welded to the main frame 13 is fixed to the intermediate portion of the seat rail 16 by welding.

A fuel tank 18 is placed on the front side of the seat rail 16 from the main frame 13, and a seat 19 is placed on the rear side thereof. The left and right sides of the seat rail 16 are covered with side cowls 20.

The connection structure of the rectangular pipes of this invention is the main frame 13.
, each joint A of the seat rail 16 and the hack stay 17,
Applies to B and C.

By the way, in the joint structure of the rectangular pipes shown in FIGS. 1 to 10, as shown in FIG. 22, the width of the hack stay 17 is narrower than the width of the pair of main frames 13, It is effective to apply it to

Although this joint part A is visible from the outside, the welded part of the seat rail 16 does not spoil the appearance because the bent part of the joint side wall that contacts the upper surface of the main frame 13 is straight.

Furthermore, in the connection structure of square pipes shown in FIGS. 11 to 20, the front end of the main frame 13 and the seat rail 16, and the rear end of the seat rail 16 and the back stay 17 are arranged in parallel. Therefore, it is applied to the joints B and C.

This embodiment can be applied even when the side cowl 20 is not used because the front end of the seat rail 16 and the bent joint side wall of the seat rail 16 of the backstay 17 are straight and have an excellent appearance.

In this way, this rectangular pipe joint structure is suitable for use in locations that are relatively easily visible from the outside.

(Effects of the Invention) As described above, this invention forms a joining side wall by bending the other side wall inward using a tongue part as a core material at the end of a square pipe, and connecting the joining side wall of this welded part to another square pipe. Since welding is done to the side wall of the pipe, the bent part of the side wall of the welded part has straightness, and it can be closely joined to the side wall of the other rectangular pipe, resulting in a suitable external shape. This is done easily and reliably, improving welding strength.

[Brief explanation of drawings]

Figures 1 to 6 are diagrams showing the process of forming a square pipe to be welded, Figures 7 to 10 are diagrams showing a square pipe welded to another square pipe, and Figure 7 is a plan view; Figure 8 is a side view, Figure 9 is a sectional view taken along line IX-IX in Figure 7, and Figure 10 is a side view.
The figure is a cross-sectional view taken along the line X-X of Section 8, and Figures 11 to 16 are diagrams showing the process of forming a rectangular pipe of another embodiment to be welded.
Figures 17 to 20 show a square pipe welded to another square pipe, Figure 17 is a plan view, Figure 18 is a side view, Figure 19 is a sectional view taken along line XIX-XIX in Figure 17,
Fig. 20 is a sectional view taken along line xx-xx in Fig. 18. Figs. 21 and 22 show an embodiment in which the present invention is applied to a body frame of a motorcycle. Fig. 21 is a side view, and Fig. 22 is a plan view. It is a diagram. 1.5...Square pipe la, lb, lc, 1cl=side wall 1e...tongue 1f...joining side wall 1g...bending part 4...welding parts 5a, 5b...side wall patent Applicant Yamaha Motor Co., Ltd. Same as above
Yamaha Auto Body Industry Co., Ltd.Figure 11
Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 8 Figure 10 Figure 18 Figure 19 Figure 20

Claims (1)

[Claims] In a square pipe connection structure in which an end of a square pipe with a square cross section is joined to a side wall of another square pipe with a square cross section by welding, one side wall of the end of the square pipe is provided with an arbitrary axial cut and a corner. A tongue is formed by providing a notch along the corner, and the tongue is bent toward the opposing side wall, and the other side wall cut along the corner is bent inward using the tongue as a core material. A joint side wall is formed, and the cut surface of this joint side wall and the first side wall is a second corner including the corner of the other rectangular pipe.
A joint structure of square pipes that is butt welded to the side wall.