Mash seam welding method and apparatus

摘要

Mash seam welding is performed to weld metal plates with thicknesses of 2 mm or more to stabilize the strength of a joint portion, reduce uneven parts of the joint portion, and ensure high strength and reliability of the joint portion. First, two metal plates, clamped with first and second clamping devices, are placed to overlap each other at their end portions. The overlapping portions (L) of the metal plates are pressed together with a pair of upper and lower electrode wheels while welding currents flow to continuously weld the overlapping portions (L) and join the metal plates. The pressing forces applied to the electrode wheels 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.

主权项

1. A mash seam welding method comprising:
clamping two metal plates with first and second clamping devices, and placing the two metal plates to overlap each other at end portions thereof; pressing overlapping portions of the two metal plates with a pair of electrode wheels, including an upper electrode wheel and a lower electrode wheel, while flowing welding current to continuously weld the overlapping portions and join the two metal plates, wherein: when the pair of electrode wheels contact joining end surfaces of the overlapping portions, feeding one of the pair of electrode wheels by position control while feeding the other one of the pair of electrode wheels by pressing force control to join the joining end surfaces of the overlapping portions, and after the joining end surfaces are welded, switching the one of the pair of electrode wheels from the position control to the pressing force control to set both of the pair of electrode wheels to the pressing force control, and in the pressing force control, controlling respective pressing forces applied to the pair of electrode wheels individually so that upper and lower welding forces acting upon the overlapping portions are equal to each other during a time when the overlapping portions are continuously welded while the welding current flows.