CONTROL DEVICE OF SPOT WELDING SYSTEM AND METHOD OF THE SAME

摘要

PURPOSE: A controller of a spot welding drive system and its method are provided to obtain the fine welding quality by exactly discriminating the welding quality and controlling a welding operation. CONSTITUTION: A controller(200) checks a starting of a welding. In starting the welding, the controller(200) stores welding voltage and welding current from a voltage measuring unit(100) and a current measuring unit(110) in an internal memory. The controller(200) checks a finishing of one spot welding. In finishing the spot welding, the controller(200) reads the voltage and the current values to be fed to welding electrodes(10a,10b) from the memory. The controller(200) converts the voltage and the current values to a resistance value by an operation algorithm. The controller(200) converts the resistance value to a size of a nugget. A finishing of the welding is checked when the size of the nugget is over a predetermined value. Otherwise, the controller(200) outputs a pulse into a switching unit(5) for increasing the welding current into the electrodes(10a,10b).