| 摘要 |
PURPOSE:To improve consumption of an electrode and reducing of a performance characteristics due to irregular width of current pulses by controlling a working gap at a desired value in a method of spark machining by producing an electric discharge in the working gap between opposing work piece and the electrode. CONSTITUTION:A time width between pulses is devided into a first time division T1, a second time division T2 and a third time division T3. When electric discharges are produced within the predetermined second time division T2, a working gap is decided to be in a proper condition and a feeding of an electrode is controlled so as to maintain this condition. When the discharge is produced within the first time division T1, the working gap is increased, while, if the discharge was not produced within the first and second time divisions, the working gap is decided to be too wide and the feeding of the electrode is controlled so as to reduce the gap. |
