| 摘要 |
PURPOSE:To accurately detect the electric discharge gap voltage by subtracting an inductance drop component of an electric discharge current and resistance drop component of the electric discharge current from the detected electric discharge gap voltage value. CONSTITUTION:To the electric discharge gap between a machining electrode 1 and a material to be machined, a voltage generating means 3 and current change rate detecting means 4 are connected in series. In a correcting means 6 for an electric discharge gap voltage signal, the inductance component of the electric discharge current is subtracted from the electric discharge gap voltage signal detected across the electric discharge 1, 2 by the calculation based on the current change rate signal to be detected. The resistance drop component of the electric discharge current detected by a resistance drop component detecting means 7 for the electric discharge current is subtracted from the elements 61 to 63 so as to be corrected for being outputted as a signal of the electric discharge gap. The adjustment of the elements 62 and 63 is easily performed in such a way that the electric discharge gap is short-circuited and a high frequency intermittent voltage is applied so that the output from the correcting means 6 becomes zero. Therefore, it is possible to detect the electric discharge machining space voltage.
|
