Electric discharge machining apparatus

摘要

The electric discharge machining apparatus comprises a wire electrode (2) for machining a workpiece (1), and a first voltage applying unit (3) for applying a voltage pulse. The voltage pulse is such that it has a rise time longer than a discharge formative time lag when a rectangular voltage pulse is applied when a distance between the workpiece (1) and the wire electrode (2) is an average value in machining and rises up to the same voltage value as the rectangular voltage pulse.