METHOD FOR CONTROLLING PLASMA CUTTING DEVICE

摘要

PURPOSE:To suppress the damage of an electrode and a nozzle by maintaining a pilot arc with low current even upon ending of one cutting operation after the pilot arc is once generated and generating a main arc without impressing a high voltage for starting in the succeeding cutting operation. CONSTITUTION:A gas for arc starting is passed between a nozzle 3 and an electrode 2 of the plasma cutting device and thereafter a high voltage for starting superposed thereon with a high frequency is impressed between the nozzle 3 and the electrode 2 to make the gas plasma, thereby generating a pilot arc between the nozzle 3 and the electrode 2. A main arc is generated by the pilot arc in the stage of cutting a material 4 to be worked. After the pilot arc is once generated, the pilot arc is maintained with low current even upon ending of one cutting operation and the main arc is generated without impressing the high voltage for starting in the succeeding cutting operation.