Electrical discharge machining method and apparaus with non-load time calculation

摘要

An electrical discharge machining method includes the steps of intermittently applying a voltage pulse to an electrical discharge machining gap between a machining electrode and a work in accordance with predetermined ON and OFF times to generate discharge, relatively moving the machining electrode and the work during generation of discharge to perform electrical discharge machining, detecting a discharge frequency during electrical discharge machining, calculating a nonload time by subtracting the predetermined ON and OFF times from a discharge repetition period based on the detected discharge frequency, and controlling a relative position between the machining electrode and the work on the basis of the calculated nonload time.