US Patent 11370045 Wire electrical discharge machine and electrical discharge machining method

A wire electrical discharge machine includes: a pulse detection unit configured to detect voltage pulses repeatedly applied between a workpiece and a wire electrode; an instability calculation unit configured to calculate the degree of instability indicating how unstable the discharge state is, by using the number of non-discharge pulses that present no voltage drop due to electrical discharge, among the pulses detected per unit time by a pulse detection unit; and a machining condition changing unit configured to change a machining condition for the workpiece, based on the calculated degree of instability.