JPS6146380A - Method of welding thin plate member - Google Patents

Abstract

PURPOSE:To improve productivity and reduce cost by forming a recess and a projection at specified positions of two thin metallic plates and after fitting the recess and projection, making pressure resistance welding at the positions, and thereby making the weld zone flat and eliminating necessity of puttying up etc. CONSTITUTION:A recess 3 is formed at a specified position of one of two thin metallic plate 1 and a projection 4 is formed at a specified position of another metallic plate 2. The recess and projection 3, 4 are fitted and overlapped and positioned. The overlapped part is held by pressure and resistance welded. The recess and projection are made flat without causing positional deviation. Thus, mending work such as puttying etc. is made unnecessary, productivity is increased and manufacturing cost is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a spot welding method belonging to resistance welding in which two thin metal members are precisely positioned and joined together.

<Prior art> Generally, in order to fix mounting parts made of a thin metal plate to a board or box made of a thin metal plate in an accurate position, mounting parts are provided in advance at respective predetermined positions. A widely used method is to perform positioning by fitting a protrusion into a positioning hole.

FIG. 4 shows a conventional method of welding a thin metal plate 2, which is a mounting part, to a thin metal plate 1, which is a substrate, by using such a positioning method.

That is, the convex portion 4a protruding from the metal plate 2 is fitted into the positioning hole 7 bored in the metal plate l, the metal plates 1 and 2 are overlapped, and the positioning hole 7 is placed in the vicinity of the positioning hole 7. Spot welding is performed to form a required number of fused parts 6a and welding is performed.

The outer surface of the metal plate 1 is usually painted to form a coating film for design and rust prevention purposes.

<Problems to be solved by the invention> However, if painting is performed directly on the outer surface of the metal plate 1, 1
It was difficult for the paint film to adhere to the gap 8 formed between the positioning hole 7 and the convex portion 4a, and the appearance was significantly impaired due to the formation of depressions on the outer surface.

In order to avoid this, putty, etc., was applied to the gap 8 to fill the dent, and the surface was made flat before painting.It requires skill to apply putty, etc. smoothly in this way. death,
This was time consuming and costly.

Means for Solving the Problems The present invention has been made in view of the above points, and has the following configuration means.

That is, the gist of the configuration of the present invention is a method of superimposing and welding two thin metal plates, in which a recess 3 is formed at a predetermined position in the metal plate 1 on one side, and a recess 3 is formed in a predetermined position in the metal plate 2 on the other side. A convex portion 4 that can be fitted into the concave portion 3 is formed at a predetermined position, and the convex portion 4 is further fitted into the concave portion 3 to overlap the two metal plates 1.2, and the concave portion 3 and the convex portion 4 are fitted. The area is heated and pressurized from above and below by resistance welding to form the recess 3. This is a method of welding thin plate members in which the protrusions 4 are welded and the outer surfaces of the metal plates 1 and 2 are formed flat.

Function> This invention is constructed as described above, and as shown in FIGS. 1 and 2.
As shown in the figure, the positioning convex part 4 of the metal plate 2 on the other side is inserted into the positioning recess 3 of the metal plate 1 on one side of the two thin metal members to be joined, and the metal plate 1 The mutual positions of and 2 are defined and superimposed.

Then, the pair of upper and lower spot electrodes 5a and 5b are connected to the recess 3 in the fitted state. The convex portion 4 is pressed and a predetermined current is applied.

At this time, due to the Joule heat generated in the pressurized area and the pressure, the concave portions 3 and the convex portions 4 are melted, and the metal plate 1.
A melted part 6 is formed which is flush with the outer surface of the second part 2. (See Figure 3) Therefore, the metal plates 1 and 2 are joined by spot welding at the position of the positioning recess 3° and the protrusion 4 so that their respective outer surfaces are flat. Embodiments of the invention will be described based on the drawings.

In FIG.
It is a private metal plate.

Reference numeral 2a denotes a mounting part, in which two positioning projections 4 that can be fitted into the recesses 3 are protruded at predetermined positions corresponding to the recesses 3. Then, the mounting part 2a is inserted into the recess 3.3 of the metal plate 1.
The convex portions 4, 4 are inserted and polymerized, and spot electrodes 5a, 5 are provided vertically facing each other to match the inserted portions.
It is compressed and heated by b.

FIG. 6 shows a longitudinal sectional view of a main part of another embodiment. This second embodiment is different from the first embodiment except that it has a carved recess 3a and a protrusion 4b that can be fitted into the recess 3a. Same as example.

This method is characterized in that the fitting portion can be easily formed.

It should be noted that this invention is not limited to the above description and illustrated examples, and its embodiments can be modified without departing from the technical idea of this invention.

Fig. 7 differs from the previous embodiment in which the metal plate 1a end is butted against the metal plate 1 end to form the same outer surface, and the metal plate 1a is joined to the extended portion of the metal plate 2 by ordinary spot welding. ψGenerally, two metal plates 1,
When 1a are butt-joined, a butt welding method is applied. According to this welding method, a raised fused portion 6b is formed at the butt portion 9 as shown in FIG.

This raised portion is finished by cutting to make the outer surface flat, and such work is time-consuming and causes high costs.

As shown in FIG. 7, if the method of this invention is applied, 2
metal plate 1. la can be butt-joined by ordinary spot welding, and a flat outer surface can be formed by simple finishing of the butt portion 9.

In this case, the metal plate 2 may be a part of the gate attachment part as described above.

<Effects of the Invention> This invention is constructed as described above, and spot welding is performed at the concave and convex portions inserted for positioning, so the outer surface of the welded metal plate is finished flat and the surface is smooth. This eliminates the need for filling with putty.

Therefore, the work process and work time can be shortened, and costs can be reduced.

Further, the positioning recesses and projections serve as marks indicating the welding area, and have the effect of allowing welding work to be performed quickly and accurately.

[Brief explanation of drawings]

Fig. 1 is a vertical cross-sectional view of main parts showing a state in which a metal plate polymerized by the welding method of the present invention is inserted between spot electrodes, g4
Figure 2 is a longitudinal cross-sectional view showing the fitting part for positioning two metal plates, Figure 3 is a vertical cross-sectional view of the main part showing the welding completed state, and Figure 4 is a state where the metal plates have been positioned and welded using the conventional method. FIG. 5 is a longitudinal sectional view of essential parts showing one embodiment of the present invention, FIG. 6 is a longitudinal sectional view of essential parts similarly showing the second embodiment, and FIG. FIG. 8 is a vertical cross-sectional view of a main part showing an embodiment, and FIG. 8 is a vertical cross-sectional view showing a butt part formed by conventional butt welding. DESCRIPTION OF SYMBOLS 1... Metal plate, 2... Metal plate, 3... Recessed part, 4...
...Protrusion 11 Figure 2 Figure B 3 B I 4 1!115 Figure 6I! IA Figure 7

Claims (1)

[Claims] A method of polymerizing and welding two thin metal plates,
forming a recess at a predetermined position on one metal plate, and forming a protrusion that can fit into the recess at a predetermined position on the other metal plate;
A method of welding a thin plate member, characterized in that the convex portion is fitted into the concave portion, the two metal plates are superimposed, and the fitting portions of the concave portion and the convex portion are resistance welded.