Resistance welding in several stages of sandwich plates

摘要

Procedure for resistance welding a sandwich plate (1) with at least one other metal component (2), where the sandwich plate (1) has two metal cover layers (1a, 1c) and a thermoplastic plastic layer (1b) arranged between the metal cover layers, where at least the area to be welded (3) of the sandwich sheet (1) is heated such that the thermoplastic plastic layer (1b) softens and is displaced from the welding area (3) by compression of the cover layers (1a, 1c), the cover layers (1a, 1c) are heat welded together with the other component (2) by means of an electric current flow through a first and a second welding electrode (6, 7), where the first welding electrode (6) has contact with a metal cover layer (1a) of the sandwich plate (1) and the second welding electrode (7) has contact with the metal component (2 ), where resistance welding comprises at least the following The steps: - (A) heating the area to be welded (3) of the sandwich plate (1) through a preheating current (Iv), where the preheating current (Iv) flows through a bridge (9) between the first welding electrode (6) and the metal component (2) to be heat-welded, and move the existing plastic between the metal cover layers (1a, 1c) of the sandwich plate (1) in the welding area (3) by applying a welding force (F) on the first and second welding electrode (6, 7), so that the metal cover layers (1a, 1c) of the sandwich plate (1) are pressed on each other, - (B) generate an adhesion weld between the metal cover layers (1a, 1c) of the sandwich sheet (1) using an adhesion welding current (Ih) between the first and the second electrode welding (6, 7), - (C) heat-weld the metal cover layers (1a, 1c) welded by adhesion of the sandwich plate (1) with the component (2) by means of a welding current (Is).