Mash seam welding method and equipment

Abstract

The invention provides a mash seam welding method and equipment. A pair of upper and lower electrode rings (1, 2) are arranged such that their axes (17, 18) incline in the opposite directions in a horizontal plane against a line (Y) perpendicularly intersecting a welding line (X) formed at the overlapping portion (L) of two metal plates (5, 6), and mash seam welding is performed while driving the electrode rings (1, 2) positively by means of electric motors (61, 62). Consequently, increase in thickness and level difference gradient can be reduced remarkably at the joint, and high joint strength can be assured by reducing stress concentration coefficient. Furthermore, a nugget (N) is jointed not to come off from the joint interface. The axes (17, 18) of the electrode rings (1, 2) incline in such a direction as the advancing direction portions (1A, 2A) of the electrode rings (1, 2) are directed to the direction where a metal plate touching the electrode rings (1, 2) at first exists in the horizontal plane. Consequently, the end portion of the metal plate at the overlapping portion (L) can be prevented from biting into the electrode rings (1, 2) to cause a flaw thereto or generation of dust can be prevented at the time of welding.

Description

Technical field [0001] The invention relates to a thin seam welding method and device. The ends of two metal plates are overlapped, and the overlapped part is pressurized by a pair of upper and lower electrode wheels, and the welding current flows while continuously welding, thereby joining the two Metal plate. Background technique [0002] The thinning seam welding machine is the following welding method: the ends of two metal plates are overlapped, and the overlapped part is pressurized with a pair of electrode wheels, and the welding current flows continuously while welding, and at the same time, the electrode wheels are used to The joint portion heated to a high temperature and softened is rolled, thereby reducing the thickness of the joint portion. However, in this welding method, the joint cannot be rolled to the thickness of the base material. The thickness of the joint increases to about 120% to 160% of the thickness of the base material (metal plate). There is a gap bet...

AI Technical Summary

Problems solved by technology

When the joint is arranged at the main body end of the electrode wheel and the surface pressure between the electrode wheel and the metal plate is maintained with the necessary accuracy, there is a problem of adjusting the electrode wheel frame moving in the vertical direction at a high level of about 0.2 mm to 0.3 mm. The problem of managing the gap, the electrode wheel bearing gap, and the amount of wear of the electrode wheel, and improving the positioning accuracy in the joint width direction

In addition, high rigidity and high precision are also required for the fastening device for positioning the position of the metal plate, which has the problem of increasing the size of the equipment and increasing the price.

Furthermore, for example, even if a nugget can be formed in the center of the joint interface, the thickness of the joint cannot be reduced to the same level as that of the base metal, and there is still a problem that application to parts requiring fatigue strength is limited.

Images