| 摘要 |
PROBLEM TO BE SOLVED: To provide a power source for plasma welding capable of determining that a keyhole of a plasma keyhole welding is penetrated. SOLUTION: The power source for plasma welding includes: a plasma arc voltage detector VD for detecting a plasma arc voltage Vp between a plasma electrode 1 and a material 4 to be welded; and a keyhole penetration determination means for determining that the keyhole is penetrated when a detection voltage Vd becomes higher than a preliminarily set reference value by inputting the detection voltage Vd of the plasma arc voltage detection detector VD. Cutoff frequency is set within a range of 0.8-1.6 Hz, and the keyhole penetration determination means includes a low-pass filter VF for removing a high-frequency component by inputting the detection voltage Vd of the plasma arc voltage detector VD. When the output voltage of the low-pass filter VF becomes equal to or higher than a preliminarily set reference value, the keyhole is determined to be penetrated. As a result, a welding bead with an adequately formed underside bead can be achieved. COPYRIGHT: (C)2011,JPO&INPIT
|
