PURPOSE: To perform DC arc welding of thin sheets with a wire of a large diameter without overmelting of base materials, by supplying electric current to the welding load only for the specified time after short-circuiting of the wire which is fed at a specified speed and the base materials and the generation of the arc.
CONSTITUTION: In a DC arc welding machine, a series circuit of a reactor 3 and a welding load 4 which is an arc generating part is connected to the output terminal of a rectifier circuit 1 through a power transistor (TR)2 as a switching element. A diode 5 for commutation is connected in parallel with said circuit and a diode 6 is connected in parallel with said reactor 3. The arc is interrupted by turning the TR2 off after a specified time t1 since the generation of the arc. Relatively high voltage is maintained with the leakage current in this stage, and when the output is short-circuited in this state, short-circuiting current is flowed by the energy released from the reactor 3. When the TR2 is turned on after the specified time t2 upon lapse of the t1, the larger short-circuiting current flows, and the arc is regenerated.
KOBAYASHI MAKOTO
KOYAMA HIDEYUKI
| JPS558397A | 1980-01-21 |