Wire electric-discharge machining apparatus

摘要

In the wire electric-discharge machining apparatus, when a measured voltage exceeds a proportional constant switching voltage that is set higher than a short circuit reference voltage, a relative feed rate determining unit (8) outputs a relative feed rate based on a preliminarily set proportional constant A according to an increase in the measured voltage. When the measured voltage is equal to an reference voltage, the relative feed rate determining unit (8) outputs an target feed rate that becomes a target value, and also outputs a relative feed rate that follows a preset proportional constant B (< A) and that is a positive value when the measured voltage exceeds the short circuit reference voltage but is below the proportional constant switching voltage.