JPH0332465A - Joining method for sheet metal by welding - Google Patents

Abstract

PURPOSE:To surely weld and join a sheet metal at a low cost by pressing an end edge of the upper face of a first plate and the lower face of a second plate, allowing them to adhere closely to each other, and thereafter, welding the part corresponding to the end edge of a first plate from a second plate side. CONSTITUTION:A first plate 1 and a second plate 2 of a metallic sheet are joined by welding. In this case, on an end edge 1a' of the upper face 1a of a first plate 1 placed on the supporting surface 3a, an end part 2' of a second plate 3 is superposed so as to get thereon. Also, by pressing a non-superposed part being adjacent to a superposed part 4 in a second plate 2 by a pressure jig 5, the end edge 1a' of the upper face of a first plate 1 and the lower face 2b of a second plate 2 are allowed to adhere closely and surely to each other. Thereafter, the part corresponding to the end edge 1a' of a first plate 1 in the superposed part 4 of a first and a second plates 1, 2 is welded from a second plate 2 side. In such a way, a step difference of a joint part can be made small to the utmost.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for overlapping thin plate welding, and particularly to a thin plate welding method suitable for welding by fusion welding such as arc welding, plasma arc welding, and laser beam welding. This invention relates to a lap welding method.

[Conventional technology]

Fills made of thin metal sheets are often subjected to surface treatment and heat treatment, and when performing these treatments, the ends of multiple coils are connected together and treated continuously in order to improve work efficiency. There is.

Joints for such uses do not require high quality, and are often desired to have a quality that does not require the joints to separate during processing.

Conventionally, as a means of connecting such applications,
Lap welding by TIG welding, which is common and relatively inexpensive, is often used.

However, in general, overlapping welding of plates with a thickness of 1 mm or less is difficult because only the upper plate turns up during welding and is more likely to melt than the welded part, and it is especially difficult to weld with a thickness of 0°5 or less. The reason why the top plate turns up like this is thought to be due to the following factors.

That is, in general, arc force, gravity, surface tension, etc. mainly act on the molten metal at the welded part simultaneously, and the shape of the molten metal is the result of the combined force of these forces. As the plate thickness decreases, the amount of molten metal decreases, so the influence of gravity decreases, and the effects of arc force and surface tension become stronger, which causes the molten metal to tend to curl up.

For this reason, it is thought that in overlap welding of plates with a thickness of 1 inch or less, only the upper plate tends to curl up during welding.

An example of a means that can eliminate the above phenomenon and is applicable to welding thin plates is lap resistance welding. Lap resistance welding, as is well known, is a method of joining metals by directly passing a large current through the welding area, heating the joint using Joule heat generated thereby as a heat source, and applying a large pressing force at the same time.

In addition, Japanese Patent Application Laid-Open No. 62-203694 describes a "method for joining metal foils" in which the overlapping parts of the thin plates are brought into strong contact (joining) by ultrasonic welding or the like, and then laser welding is performed. provided.

[Problem to be solved by the invention]

However, each of the above known means has the following disadvantages.

In other words, the former type of lap resistance welding requires large, complex, and expensive welding equipment, power supply equipment, and various control devices, and it is difficult to join when the plate thickness is 1III1 or less (or when the plate thickness is thin). The more difficult it is to weld thin plates, and although it is not impossible, it is extremely difficult and inefficient.In addition, in the latter case, laser welding requires the prior implementation of the process mentioned above. The degree of bonding (or “strong contact”) required must be such that ultrasonic welding must be performed;
In addition to being expensive in terms of process, laser welding, which requires very expensive equipment, is performed afterwards, making the process extremely expensive as a whole. Furthermore, since both of these methods involve overlapping welding, there is a step at the joint, and when used to join coils, for example, the step can cause various problems on the processing line. Ta.

Another method for joining thin plates is to form a butt joint using high-frequency pulsed TIG welding.This method allows the height difference in the joint to be kept low, but requires very strict dimensions for the butt part. In addition to requiring precision, the equipment was also large-scale, leading to high costs.

The present invention has been made in view of the above circumstances, and provides a method for joining thin plates by welding, which can achieve the joining of thin plates by simple means and at extremely low cost, which has been considered difficult in the past. The purpose is to

[Means to solve the problem]

In the present invention, when joining a first plate material and a second plate material made of thin metal plates by welding, the first plate material and the second plate material are attached to the upper surface edge of the first plate material placed on a support surface. Overlapping the ends of the second plate materials to be matched so that the ends ride on the upper edge of the first plate material, and pressing downward the non-overlapping portions of the second plate materials that are close to the overlapping portions. The upper surface edge of the first plate material and the lower surface of the second plate material are brought into close contact with each other, and then the edge edge of the first plate material at the overlapping part of the first plate material and the second plate material This is characterized by welding the portions corresponding to the second plate from the second plate side.

[Effect]

When a second plate material is overlapped so as to ride on the edge of the first plate material, and the non-overlapping part of the second plate material close to the overlapping part is pressed downward, the first plate material and the second plate material are separated from each other. One of the plates is strongly pressed into line contact at the upper edge of the first plate, and the two plates are strongly brought into close contact with each other at this location. By welding the portions where the two plates are in close contact with each other, the upper plate (second plate) is prevented from curling up at the welded portion, and reliable welding is achieved.

At this time, the portion of the overlapping portion of the upper plate other than the welded portion is melted and cut at the same time as welding, and no overlapping portion remains in the welded plates, and the difference in level at the connection portion is small.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 illustrates a first embodiment of the present invention. Note that this example shows an example in which the present invention is applied to TIG welding.

Reference numerals 1 and 2 in the figure represent plate materials (thin metal plates) to be joined together, and the plate thickness is 21 or less. The following method may be used to join these plate materials 1 and 2 together.

First, the first plate 1 is placed on the backing metal 3, and the end 2 of the second plate 2 to be joined to the first plate 1 is attached to the end 1' of the first plate 1. ' are stacked so that this end 2' rides on the edge 1a of the upper surface 1a of the first plate l. At this time, the dimensions of the overlapping portion 4 of both plate materials 1 and 2 (
Overlap allowance) is not particularly limited, but from the viewpoint of dimensional accuracy it should be 0.
, 5 ms or more.

After the ends of the first plate material 1 and the second plate material 2 are overlapped in the above state, next, the non-overlapping part of the second plate material 2 and a position close to the overlapping part 4 is pressurized and cured. Ingredients 5
Press down. The pressing jig 5 extends in the longitudinal direction along the overlapped portion 4, and therefore the second plate material 2 is uniformly pressed near the overlapped portion 4 along the overlapped portion 4. state. Pressure jig 5 here
The material of the backing metal 3 is not particularly limited, and may be stainless steel, common steel, copper, or the like.

As a result of the above, a wedge-shaped gap 6 is formed between the lower surface 2b of the end portion 2' of the second plate material 2 and the upper surface (supporting surface) 3a of the backing metal 3. That is, as a result, the first plate material 1
The upper surface edge 1a' and the lower surface 2b of the end portion 2' of the second plate 2 are in line contact.

Thereafter, a portion of the overlapping portion 4 between the first plate material 1 and the second plate material 1 corresponding to the edge 1a of the first plate material 1 may be welded from the second plate material 2 side.

According to this method, the end portion 2' of the second plate material 2 is overlapped so as to ride on the end portion 1' of the first plate material l, and the second plate material 2
By pressing downward the non-overlapping part close to the overlapping part 4, the upper surface edge 1a of the first plate material 1 and the lower end surface 2b of the second plate material 2 are brought into close contact with each other in a line contact state, and By welding the close contact portion, the upper plate (second plate material 2) is prevented from curling up at the welded portion, and reliable welding can be performed.

Moreover, in this case, by overlapping and pressing both the plate materials 1.2 as described above, the upper surface edge of the first plate material 1 at the end 2' of the second plate material 2 forming the overlapping part 4 is The part on the tip side of the part in contact with the upper surface 1a of the first plate 1 has a reaction force that can effectively bring the second plate 2 into close contact with the upper edge 1a of the first plate. A gap 7 is formed in between, and the surface 1a is lifted from the surface 1a. Therefore, if the dimension of this raised portion 2A is large, that is, if the dimension of the overlapped portion 4 is large, this raised portion 2A will be attached to the welded edge 1 of the welded portion 10 during the above-mentioned welding.
It will be fused and removed from 0a. On the other hand, when the raised portion 2A is small, the two raised portions are melted during welding and form the welded portion 10 as weld metal.

Therefore, according to this method, not only can thin plates be welded together easily, but also joints with small steps can be formed.

Experimental Example-1 As shown in FIG. 2, thin plates were joined together by welding under the following conditions. In addition, in the same figure, the code 1
1 indicates a TIG welding machine, and 12 indicates a TIG torch.

Other members that are the same as those in FIG. 1 are given the same reference numerals and their explanations will be omitted.

- Test piece (plate material 1.2): JISA1100 aluminum material, plate thickness 0.2 mm.

Dimensions 300X300mm -Dimensions of overlapping part 4: 1mm.

- TIG welding machine 11 settings: current 80A.

Voltage 15V.

・Welding speed: 2m/min.

As a result, a good welded area was obtained, with no curling up of the upper plate (second plate material 2) and almost no level differences.

Experimental Example-2 Under the following conditions, thin plates were joined by welding as shown in FIG. 3. In this experimental example, a stepped backing metal 3' is used as the backing metal 3 as shown in the figure, and the first plate material 1 is placed on the stepped part 3A, and the tip thereof is placed on the stepped part 3A.
It was assumed that it would be placed in line with the edge of the

- Test piece (both plates 1 and 2): JISA5182 aluminum material, plate thickness 0, 2 arm.

Dimensions: 300 x 300 mm.

・Dimensions of overlapping part 4: 2+11111° ・Settings of TIG welding machine 11: Current 75A.

Voltage 15V.

・Welding speed: 2m/11in.

As a result, a good welded area was obtained in which the upper plate (second plate material 2) did not turn over and almost no level difference was observed.

In addition, in this example (experimental example), since the backing metal is stepped in this way, the contact pressure (adhesion degree) between the upper surface edge 1a of the first plate material l and the second plate material 2 As a result, even higher welding performance can be achieved.

Experimental Example 3 Under the following conditions, thin plates were joined by welding as shown in FIG. 4.

- Test piece (plate material 1.2): JIS A3003 aluminum material, plate thickness 0.3 mm.

Dimensions: 300 x 300 mm.

・Dimensions of overlapping part 4: 20II+n+.

・Setting of TIG welding machine 11: Current 85A.

Voltage 15V.

・Welding speed: 2m/min.

As a result, the raised portion 2A of the upper plate (second plate material 2)
The welding edge 1 is turned up as shown in Fig.
While the weld was fused from 0a, the upper plate did not curl up at the other weld edge 10b, and the step of this weld 10 was less than half the plate thickness, resulting in a good weld.

In this way, when the dimensions of the overlapping portion 4 of both plate materials 1.2 are increased, the upper plate portion of the overlapping portion 4, that is, the raised portion 2A is removed by being cut by melting during welding, and therefore Even when the overlapping portion 4 is made large, no overlapping portion is formed at the joining portion of both plate materials 1.2, and it is possible to perform joining with almost no step formation. Making the overlapping part 4 wide in this way and fusing the two raised parts of the top plate as a result solves the problem of the curling up of the top plate, which was mentioned earlier as a problem with the conventional overlap welding method of thin plates. This can be said to be a method that actively utilizes the feeling of misadventure. In the method according to the present invention, the first plate material 1 and the second plate material 2 are formed with a close contact portion in which both are in strong contact with each other, and the close contact portion is welded to ensure welding.

Although the above embodiment shows an example in which the present invention is applied to TIG welding, the present invention is applicable to other arc welding such as coated arc welding and MIG welding, as well as other fusion welding such as plasma arc welding and laser welding. It can be applied to welding methods.

Further, the type of metal to which the present invention is applied is not particularly limited, and the present invention can be favorably applied to, for example, iron plates, aluminum plates, copper plates, titanium plates, and the like.

Furthermore, the thickness of the plate material (thin metal plate) applied to the present invention is preferably 21111 mm or less, more specifically 0.
．． It is preferably about 1 mm to 1.51 mm. The reason why 2ff1m or less is preferable is that when the plate thickness exceeds 21, it is possible to relatively easily join by welding without using the method of the present invention. [Effects of the Invention] As explained above, according to the present invention, thin plates can be joined together by welding by extremely simple means, at low cost, and without using any large-scale equipment or requiring special dimension settings. In addition to this, it is also possible to minimize the level difference at the joint. Moreover, it can be widely applied to fusion welding such as arc welding, plasma arc welding, and laser beam welding, and can be applied to various metals that can be welded by these welding methods. can.

[Brief explanation of drawings]

1 to 5 show embodiments of the present invention. FIG. 1 is a side view showing the welding state of plate materials, and FIGS. 2, 3, and 4 each show an embodiment of the present invention. FIG. 5 is a schematic side view showing a state in which the present invention is applied to welding; FIG. I...First plate material, 1'...End, 1a...Top surface, la...
・Edge, 2...Second plate material, 2'...
...End, 2b...Bottom surface, 2 people...
- Raised part, 3a...Top surface of backing metal (
Support surface), 4...Overlapping part.

Claims (1)

[Claims] When joining a first plate material and a second plate material made of thin metal plates by welding, a second plate material to be joined to the first plate material is placed on the upper edge of the first plate material placed on the support surface. The end portions of the second plate material are overlapped so that the end portions ride on the upper edge of the first plate material, and the non-overlapping portion of the second plate material adjacent to the overlapping portion is pressed downward. The upper surface edge of the first plate material and the lower surface of the second plate material are brought into close contact with each other, and then the edge of the first plate material corresponding to the edge of the first plate material at the overlapping part of the first plate material and the second plate material is A method for joining thin plates by welding, characterized in that parts are welded from the second plate side.