JP2986135B2 - Arc welding method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an arc welding method for forming a gap in a welding surface in advance and performing lap welding.

[0002]

2. Description of the Related Art First, a conventional method for performing arc welding of superposed metal plates using a plasma arc welding machine or the like will be described with reference to FIG. The objects to be welded 1 and 2 are like a relatively thin steel plate, and the object to be welded 2 is composed of separate metal plates 2A and 2B having one end surfaces abutting each other. In the case where the workpieces 2A and 2B and the workpiece 1 are overlapped and welded while welding the butt portions of the workpieces 2A and 2B of the workpieces 1 and 2 thus arranged, FIG. As shown in A), the torch 3 is arranged above the contact surface X between the workpieces 2A and 2B, an arc column 4 is generated between the workpiece and the workpiece, and the torch 3 is moved along the contact surface X. By doing so, welding was performed.

When welding is performed as described above, a nugget (metal fusion portion) N formed on the workpieces 1 and 2 is joined as shown by hatching in FIG. In view of this, there is a problem that a desired welding strength cannot be obtained because the surface cannot be made so large. Workpieces 1, 2
Trying to increase the area of the nugget N at the joint surface of
This is because welding marks are formed on the surface of the workpiece 1, which is not preferable.

[0004] In particular, when the workpieces 1 and 2 are galvanized steel plates, the zinc at the joint surfaces of the workpieces 1 and 2 is melted, gasified, and blown out of the molten metal. Therefore, there is a problem that pinholes and spatters are generated.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an arc welding method capable of welding in a short time and obtaining high welding strength, and without generating pinholes or spatters in a welded portion. Another object of the present invention is to provide an arc welding method capable of welding galvanized steel sheets.

[0006]

In order to achieve the above object, a first galvanized steel sheet and a second galvanized steel sheet composed of two or more separate bodies are overlapped and arc welded by an arc torch. In the method, the separate body is arranged so that a gap for releasing vaporized zinc gas generated during welding is present, and the first galvanized steel sheet has a projection, and the projection is placed in the gap. The gap is smaller than the width of the arc column where the arc torch is generated, and arc welding is performed along the gap.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the arc welding method of the present invention will be described with reference to FIG. 1. A first workpiece 1 has a projection P. FIG. The projection P has a maximum width substantially equal to the width W of the gap S between the second left and right workpieces 2 and the second left and right workpieces. It has a height equal to or less than the thickness of the object 2, and various shapes are conceivable.
Then, the width W of the gap S between the separate left and right workpieces 2 to be welded 2 is less than or equal to the width of the arc column 4, and if it is larger than that, the intended welding is not performed. The width of the arc column 4 depends on the diameter of the constricted hole (not shown) of the torch 3 and the distance between the constricted hole (not shown) and the work 2 to be welded separately.

[0008] With the workpieces 1 and 2 arranged as described above clamped in the direction indicated by the arrow, a plasma arc torch 3 is disposed about 3 mm above the gap S, and a plasma arc torch is provided between the workpiece and the workpiece. The arc welding is performed by running the plasma arc torch 3 along the gap S at a constant speed with the arc column 4 formed. By welding in this manner, a nugget N having a shape as shown in FIG. The nugget area on the welding surface between the workpiece 1 and the left and right workpiece 2 is larger than before, and the welding strength can be reliably improved. At this time, the projection P of the first workpiece 1 has a role of filling the gap S and a function of accelerating the melting of the welded portion of the first workpiece 1, so that the recess of the welded portion can be small. Also the first
Since the workpiece 1 is easily melted, the arc welding time can be further reduced.

Here, when the first workpiece 1 and the second left and right workpiece 2 are galvanized steel sheets,
In particular, this arc welding method has a great effect. Since the gap S between the workpieces is used in this manner, the workpiece 1
Since zinc gas generated during the melting of (1) and (2) escapes from the gap S into the atmosphere for a while, pinholes and spatters, which have conventionally been regarded as major problems in welding galvanized steel sheets, do not occur.

Next, FIG. 2 shows an embodiment in which the workpieces 1, 2, and 2 'made of three metal plates are arc-welded. In this case, as in the above-described embodiment, the first workpiece is welded. Object 1 is projection P
And the overlapped second workpiece 3 and third workpiece 2 ′ have a gap S that is approximately the same as or larger than the maximum width of the projection P. These workpieces can be formed by the same arc welding method as the method shown in FIG.

In these embodiments, the gap S varies depending on the expansion of the arc column, its current capacity, the thickness of the work to be welded, etc., but can be made wider by the function of the projection P. There are many.

[0012]

As described above, according to the present invention, a method for performing arc welding with an arc torch by overlapping a first workpiece and a second workpiece comprising two or more separate bodies. Wherein the first workpiece has a projection, the projection of the first workpiece fits between the second workpieces, and the gap is smaller than the width of the arc column where the arc torch is generated. Since arc welding is performed along the gap, arc welding can be performed in a short time without increasing welding dents, and welding strength can be improved. Further, when the object to be welded is a galvanized steel sheet, gas generated by zinc during welding escapes into the atmosphere for a while, so that pinholes and spatters are not generated, and the practical effect is large.

[Brief description of the drawings]

FIG. 1 is a view for explaining an embodiment of an arc welding method according to the present invention.

FIG. 2 is a view illustrating another embodiment of the arc welding method according to the present invention.

FIG. 3 is a view for explaining a conventional arc welding method.

[Explanation of symbols]

 1,2,2 '... workpiece 3 ... arc torch 4 ... arc column P ... workpiece 1 protrusion N ... Nugget

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23K 9/02 B23K 10/02 B23K 33/00

Claims (1)

(57) [Claims] In a method of superimposing a first galvanized steel sheet and a second galvanized steel sheet composed of two or more separate pieces and performing arc welding by an arc torch, a vaporized zinc gas generated during welding is released. And the first galvanized steel sheet has projections, and the projections are accommodated in the gaps, and the gaps are formed in an arc column where the arc torch is generated. An arc welding method having a width smaller than a width and performing arc welding along the gap.