Method and device for controlling or regulating the contact and the contact pressure between resistance welding electrodes and a workpiece which is to be welded

摘要

The method is characterised in that the presence of a leakage current in the control block (12) when its impedance is at the separation value, and a residual voltage on the primary side (10) of the transformer (9) is thus used in order continuously to measure the voltage on the primary side and from this to derive information on the presence or absence of a contact between the electrodes (1) and the workpiece (2) and on the magnitude of the contact pressure which these exert on the workpiece, and to control the start of the actual welding and the transportation of the workpiece away after the welding. IMAGE