METHOD FOR JUDGING STABILITY OF WELDING AT STARTING ARC AND DEVICE FOR JUDGING STABILITY

摘要

PROBLEM TO BE SOLVED: To prevent the flowing of welded defective caused by the unstability of arc discharging state at the time of arc-starting a consumable electrode type gas shielded arc welding executing the welding while alternately repeating the short circuit and the arc. SOLUTION: This device transmits analog signals by detecting the welding current and the welding voltage with means 7, 8. Each analog signal is made to a digital signal with an A/D converter 9. Both digital signals are calculated with a CPU 10 to calculate one or more items among five items of a wire sticking time, arc break-off time, long time short-circuit time, no-load voltage time and current standing-up speed of the arc starting. When the difference between the calculated value of any item and the reference value exceeds the permissible range, it is decided that the welding is unstable or defective, and that result is displayed.