DEFECT GENERATION DETECTING METHOD IN RESISTANCE WELDING

摘要

PURPOSE:To detect automatically a defect part and to increase the productivity of weldment and the reliability by separately detecting the high frequency component to appear in the voltage between welding electrodes and the current to pass therethrough and by detecting the generation of defect parts. CONSTITUTION:A voltage signal Vx is vibrated at the time when a burning and hole opening, etc. are caused on a metallic composite material and becomes in the waveform that a high frequency component Vh is placed on power source voltage component V. High frequency separating filter 12 outputs by separating the high frequency component Vh and comparator 13 generates a defect detecting signal P. A flip-flop 15 is set on generation of this defect detecting signal P and by the set output a display lamp 16 is lit and the generation of defect part is reported to an operator. Simultaneously the number of defect generating times is displayed by a displayer 18 through pulse counter 17.