METHOD FOR DETECTING WELD DEFECTS OF CAPACITOR DISCHARGE TYPE STUD WELDING MACHINE AND DEFECT DETECTION DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a method for detecting defects of stud welding, capable of carrying out simple detection of defects as compared with a conventional one by exactly capturing a changing spot of a contact point, and also to provide a defect detection device.;SOLUTION: A CP optimum time zone D3 suited for generation of the contact point where a stud comes in touch with a base material and is welded and joined to it is preliminarily determined; a measuring time zone D4 is preliminarily determined to include the whole of the CP optimum time zone D3; a welding current value or a welding voltage value is measured a plurality of times in the measuring time zone D4 during actual stud welding; a changing time spot where the current value or the voltage value changes from a fall to a rise is detected by comparing the sizes of a plurality of the measured welding current values or welding voltage values, and detection of weld defects is carried out based on whether the detected changing time spot is within the CP optimum time zone D3.;COPYRIGHT: (C)2013,JPO&INPIT