| 摘要 |
PURPOSE:To prevent a wire electrode from braking, by discriminating a gap state from frequency distribution of a voice signal in an electrode gap, while controlling servo reference voltage in time of being servo on length of the electrode gap between the wire electrode and a work. CONSTITUTION:A voice sensor, as a detecting device, comes into contact with a wire electrode 2 being stretched between upper and lower guides 8A and 8B, and this voice sensor 16 senses a voice signal in a gap transmitted via the wire electrode 2. A spark gap state discriminating device 17 amplifies the voice signal outputted out of the voice sensor 16, discriminating the frequency and performing an analytic process, thus it discriminates a spark gap state. According to the discriminated result, servo reference voltage in time of being servo on length of the electrode gaps between the wire electrode 2 and a work 1 is controlled. |
