Patent ID: 6756557
Filing Date: 2004-06-29
Classification: B23H

Abstract:
A power source apparatus for wire electric discharge machining capable of applying voltages of both of positive and opposite polarities to a gap between a wire electrode and a workpiece, comprising a DC power source for supplying a DC voltage to the gap between the wire electrode and the workpiece, switching means for performing switching of the DC voltage and control means for performing on-off control of the switching means, characterized in that there is provided control means for applying a first voltage pulse to the gap for predetermined time and then applying a second voltage pulse of a polarity opposite to the first voltage pulse for predetermined time necessary for the gap voltage to become a predetermined voltage lower than or equal to a voltage capable of starting an electric discharge corresponding to each machining condition of machining in machining liquid, machining in mist or machining in gas, and use is made in machining for performing at least two machining operations selected from machining in the machining liquid, machining in the mist and machining in the gas.