JPH1177384A - Aluminum alloy frame connection structure - Google Patents

Abstract

(57) [Problem] To obtain a stable welding strength by making a connecting structure of a hollow aluminum alloy frame easy to maintain a constant arc length at the time of welding. SOLUTION: An inner piece 3 extending between the two frames 1 and 2 is fitted into a contact portion of an opening end of the both frames 1 and 2 to be connected to connect the two frames 1 and 2, and an opening of the both frames 1 and 2 is connected. A slit S is formed at the end, and a convex portion 3a fitted to the slit S and having a height equal to the thickness of the slit S is formed in the inner piece 3 to fit the slit S and the convex portion 3a. The part is flushed and this part is arc welded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a joining structure of a hollow aluminum alloy frame, and more particularly to a joining structure which is joined by arc welding.

[0002]

2. Description of the Related Art Conventionally, as this type of coupling structure, a projection is formed on a joint member connecting the open ends of both frames to be coupled so as to be located between the two open ends. A groove is formed between the frame and the opening end of the frame to arc-weld the frame and the joint member (JP-A-59-20767).
And Japanese Patent Application Laid-Open Publication No. H11-157572 discloses a method in which a plug hole is formed in an overlapping portion between a frame and a joint member or in an overlapping portion between frames to be joined, and the overlapped member is plug-welded by arc welding. I have.

[0003]

When a groove or a plug hole is to be formed by arc welding, it is difficult to keep the arc length constant, and the welding quality tends to vary.

[0004] In view of the above problems, an object of the present invention is to provide a joint structure which can easily maintain a constant arc length and can obtain stable welding quality.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a connecting structure of a hollow aluminum alloy frame, wherein an inner piece extending over both frames is inserted into a hollow portion of both frames to be connected. A notch is formed at the opening end of both frames by connecting the two frames, and a convex portion which fits into the notch and has a height equal to the thickness of the frame at the notch portion is formed on the inner piece. Then, the fitting portion between the notch and the projection is arc-welded.

[0006] With this configuration, it is only necessary to weld the fitting portion. Therefore, even if there is a difference depending on the shape of the fitting portion, the contact portions of the open end faces of the two frames to be connected are formed over the entire circumference. The welding operation is easier than when welding is performed over a wide area. In particular, when the length of the girth of the frame to be connected is long, the number of welding steps is reduced, which is advantageous.

Further, if there is unevenness in a portion to be arc-welded, it is difficult to stabilize the arc length and the welding quality tends to vary. In addition, the height of the convex portion is equal to the thickness of the frame, the surface of the fitting portion is flush, and the unevenness of the fitting portion to be welded is eliminated, so that the arc length is stabilized and a predetermined penetration is obtained, Stability of welding quality such as welding strength is improved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, reference numerals 1 and 2 denote hollow aluminum alloy frames. Both the frames 1 and 2 are formed by extruding and cutting into appropriate lengths, and have the same cross-sectional shape perpendicular to the direction of extrusion. Also, three notched slits S extending in the extrusion molding direction of the frames 1 and 2 are formed at the open ends of the frames 1 and 2, and when the open ends of the frames 1 and 2 are brought into contact with each other, Slit S on both frames
Are connected at the contact portion at the opening end.

When connecting the two frames 1 and 2, the inner piece 3 is first inserted into the hollow portion from the opening end of the two frames 1 and 2 so as to be disposed over the two frames 1 and 2. Frames 1 and 2 are connected. Like the frame, the inner piece 3 is an extruded product made of an aluminum alloy. The outer shape of the cross section perpendicular to the extrusion molding direction of the inner piece 3 matches the inner shape of the cross section perpendicular to the extrusion molding direction of the frames 1 and 2.
The inner piece 3 can be inserted into the hollow portion 2 without play.
Therefore, when the inner piece 3 is inserted, the strength of the connecting portion is reinforced.

The length of the inner piece 3 is twice as long as the slit S of the frames 1 and 2, and the inner piece 3 is inserted into the hollow portion of the frames 1 and 2 on its outer surface. The protrusion 3a that fits into the slit S when extended is formed over the entire length so as to extend in the extrusion molding direction. Therefore, when the open ends of the frames 1 and 2 are brought into contact with each other, if the inner piece 3 is inserted into the hollow portion from the open ends of the frames 1 and 2, the open ends come into contact at an intermediate position of the inner piece 3, Slit S corresponding to both ends of projection 3a
Abuts the end on the closed side of. That is, inner piece 3
Are positioned so that the lengths of the fittings into the frames 1 and 2 are equal, and the length of the fitting portion between the protrusion 3a and the slit S is evenly distributed to the frames 1 and 2.

With the two frames 1 and 2 connected in this way, the fitting portion between the projection 3a and the slit S is welded by arc welding such as MIG welding as shown in FIG. Combine 1 and 2. As described above, since the lengths of the fitting portions are evenly distributed to the frames 1 and 2, the welding strength between the frames 1 and 2 and the inner piece 3 does not vary. Frame 1,
When the inner piece 3 is inserted into the frame 2, the two frames 1, 2
Since the relative position is determined, the welding operation can be performed accurately, and at the same time, distortion and deformation are less likely to occur at the time of welding, and the joining accuracy is improved. If the welding range is changed by changing the length of the slit S, the welding strength can be adjusted to a desired strength.

By the way, if the arc welding portion has irregularities, it is difficult to stabilize the arc length and the welding quality such as welding strength tends to vary. The height of the inner piece 3 up to the end face of the projection 3a is made equal to the thickness of the frame 1, 2 at the portion where the slit S is formed (see FIG. 1 (C)). Since the surface of the fitting part is flush, there is no unevenness from the fitting part to be welded,
The arc length is stable, the variation in welding quality is suppressed, and the stability of welding quality is improved.

If the fitting portions of the slits S and the projections 3a are welded to join the frames 1 and 2, the abutting portions of the open ends of the frames 1 and 2 to be joined are formed over the entire circumference. Since it is not necessary to perform welding all over, welding work is easy. Particularly when the waist of the frame to be connected is long, the effect that the number of welding steps is greatly reduced is produced, and the productivity is improved.

Further, when the shape of the notch is a slit as in the present embodiment, the projection fitted to the notch can be advantageously formed into the inner piece by extrusion, but the shape of the notch is As long as the portion can be formed, the shape may be, for example, a groove-like triangle.

[0015]

As described above, according to the present invention, since the surface of the fitting portion to be welded is flush, there is no unevenness from the welding portion, the arc length is stabilized, and the welding quality such as welding strength is improved. Stability is improved.

[Brief description of the drawings]

FIG. 1A is an exploded perspective view showing a frame connecting structure of the present invention, FIG. 1B is a perspective view showing a state in which frames to be connected are connected, and FIG. 1C is a sectional view taken along line III-III of FIG. Diagram shown

FIG. 2 is a perspective view showing a state where a fitting portion between a slit and a convex portion is welded.

[Explanation of symbols]

 1, 2 frame 3 inner piece 3a convex part S slit (notch)

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Claims (1)

[Claims] In a joint structure of a hollow aluminum alloy frame, an inner piece extending over both frames is inserted into a hollow portion of both frames to be joined, and the two frames are connected to each other. And forming a convex portion that fits into the notch and has a height equal to the thickness of the frame of the notch portion in the inner piece, and arc-welding the fitting portion between the notch and the convex portion. An aluminum alloy frame connection structure characterized by the following.