WIRE-CUT ELECTRIC SPARK MACHINING APPARATUS AND METHOD

摘要

A wire-cut electric spark machine comprising a device (6) for taking up a wire electrode (1) to transport the wire electrode along a wire transport path, a servomotor (4B) for imparting a tension to the wire being transported, an NC apparatus (10) for generating a signal representing a preset value of the tension, a tension detector (9) for detecting the tension and generating a signal representing the detection value, and a tension controller (13) for processing the signal representing the preset value of the tension and the signal representing the detection value of the tension. The tension controller includes two notch filters (19, 20) for blocking different frequencies connected in cascade. An unwanted frequency setter (21) sets the minimum value of an unwanted frequency to one of the two notch filters and the maximum value to the other.