JPS57202976A - Consumable electrode type arc welding machine - Google Patents

Abstract

PURPOSE:To melt the coasting part of a consumable electrode effectively and to prevent the formation of a spherical mass at the leading end by decreasing the output of a welding electric power source with delay for a prescribed time from a welding end command signal, and further interrupting the power source output after a prescribed time. CONSTITUTION:When the under-welding signal from a starting circuit 11 is interrupted at the time (b), a motor rotating speed control circuit 16 interrupts the output and a motor 18 is quickly decelerated and stops after the DELTAt time. On the other hand, a flip-flop circuit 14 is held set and therefore it keeps flowing the output of a reference voltage setter 7 to a welding electric power source 1. When a delay circuit 12 starts timing and times out after the set time t1, a switching circuit 9 switches to a reference voltage setter 8, thereby reducing the output of the power source 1 to a low voltage E2. A time limit circuit 13 starts timing from the end point of the circuit 12 and when it times out at the set time t2, the circuit 14 is reset and a switch 10 is opened and therefore the power source circuit is interrupted.