PURPOSE: To remarkably improve the efficiency of the crater treating work by performing welding work by using only one of the 1st and 2nd welding power sources after the welding work has been performed by using both of these power sources simultaneously.
CONSTITUTION: When welding is started by two power sources, main and auxiliary power sources 11, 12, a relay 16 is energized and its contacts 16S are closed, then voltage is applied to a delay timer 20 and its contacts 20S are closed for a preset time. Then, a relay 21 is energized, and its contacts 21S are closed, so that the regular welding is accomplished by the large current transformed by the respective transformer 101, 102 of the power sources 11, 12. When the preset time elaspses, the operation of the timer 20 goes off, and the contacts 20S are opened, by which the relay 21 is de-energized, and its contacts 21S are opened, so that the power supply from the power source 11 is broken. Hence, the crater treatment welding of the low current using exclusively the power source 12 is accomplished.
| JPS5351153 | ONEESIDE WELDING |
| JPS56114593 | MANUFACTURE OF VALVE SEAT |
SASAKI AKIRA
HIROSE KOUHEI
