Abstract: A wire cut electrical discharge processing device comprising a device (6) which takes up a wire electrode, the wire electrode (1) traveling along a wire conveying path; a servo motor (4B) which applies tension to the traveling wire electrode; a NC device which generates signals which indicate a set value for the tension; a force detector (9) which detects the tension applied to the wire electrode and generates signals which indicate the detected value; and a tension control device (13) which processes signals which indicate the set value of the tension and the signals which indicate the detected value of the tension and which supplies speed command signals which direct the speed of rotation of the servo motor. The tension control device comprises two continuously connected notch filters (19 and 20) which check different frequencies.

Abstract: A wire cut electric discharge machine including a device (6) for pulling a wire electrode (1) such that it travels along a wire transport path, a servo motor (4B) which applies tension to the traveling wire electrode, an NC device which generates a signal indicating a tension setting value; a tension detector (9) which detects the tension applied to the wire electrode and generates a signal indicating the detected value, and a tension control device which processes the signal indicating the tension setting value and the signal indicating the tension detection value, and commands the servo motor rotational speed. The tension control device includes a non-essential frequencies setting circuit (20) which sets non-essential frequencies and generates a signal indicating that setting value, and an electric filter device (19), which blocks non-essential frequencies based on the non-essential frequencies setting circuit output signal.