Pressure seam welding method and device

Abstract

In mash seam welding for performing to weld metal plates with thicknesses of 2 mm or more, it is possible to stabilize the strength of a joint portion, reduce uneven parts of the joint portion, ensure high strength and reliability of the joint portion, and join metal plates with thicknesses of 4.5 mm or more. Two metal plates (5, 6) are clamped with first and second clamping devices (7, 8), and the two metal plates (5, 6) are placed to overlap each other at their end portions, and then overlapping portions (L) of the two metal plates 5, 6) are pressed with a pair of upper and lower electrode wheels (1, 2) while welding currents flow to continuously weld the overlapping portions (L) and join the two metal plates. The pessing forces applied to the upper and lower electrode wheels (1, 2) are controlled so that upper and lower welding forces acting upon the overlapping portions are equal to each other during the time when the overlapping portions are continuously welded while the welding currents flow.

Description

technical field [0001] The present invention relates to a mash seam welding method and device for joining two thick metal plates. Background technique [0002] Pressure seam welding is a welding method that overlaps the ends of two metal plates, pressurizes the overlapped part with a pair of electrode wheels, turns on the welding current, and performs welding continuously. The joint part heated to a high temperature state and softened is rolled, thereby reducing the thickness of the joint part. [0003] As the prior art of a mash seam welding apparatus for joining thick metal plates, for example, the techniques described in Patent Document 1 and Patent Document 2 are known. [0004] In Patent Document 1, the following problem is proposed as a problem in the case of joining thick metal plates: as in Patent Document 1, Figure 13 As shown, the sheet metal (the material to be welded) must be bent quite extreme, which exerts considerable force on the clamping device, thus causi...

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Problems solved by technology

[0004] In Patent Document 1, the following problem is proposed as a problem in the case of joining thick metal plates: as in Patent Document 1, Figure 13 As shown, the sheet metal (the material to be welded) must be bent quite extreme, which exerts considerable force on the clamping device, thus causing the clamping device to deform or even break

[0005] In Patent Document 2, as a problem in the case of joining high-strength steel plates, the following problems are raised: Referring to FIG. 20) is in contact with the electrode wheel, so the damage caused to the electrode wheel is relatively large, and because the welding current is concentrated at the corner of the lower metal plate (21 of Figure 8 of Patent Document 2), welding spatter (corner part The phenomenon that the current density is excessive, so that the melting is scattered, and the sputtering remains on the metal plate), and good welding results cannot be obtained.

Similarly, in the case of joining thick metal plates, the current needs to be increased due to the increase in the volume of the joint, and the pressing force of the electrode wheel must be increased because the rigidity of the metal plates becomes higher. The same principle will produce the same problem in the situation

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