摘要 |
In order to detect a machining state of a wire electric discharge machine, the state of a machining gap is classified into three categories; an open-circuit state in which electric discharge does not occur after a first predetermined level is reached or surpassed by a machining-gap voltage, an electric discharge state in which electric discharge occurs after a second predetermined level is reached or surpassed by the machining-gap voltage, whereby the machining-gap voltage becomes lower than the second predetermined level, and a short-circuit state wherein a third predetermined level is not reached or surpassed by the machining-gap voltage. An average voltage in the machining gap is determined based on voltages in these states and the number of cycles of voltage application to the machining gap, number of open-circuits, number of discharges, and number of short-circuits per unit time. |