Patent ID: 9744608
Date: 2017-08-29
CPC Classifications: B23H

Claim:
1. A wire electric discharge machine for machining a workpiece into a desired shape by changing a relative position between a wire electrode and the workpiece while causing discharge by applying a voltage to a machining gap between the wire electrode and the workpiece, the wire electric discharge machine comprising: a secondary power supply including a DC power supply and a switching element, wherein the secondary power supply is configured to apply an AC pulse voltage; a primary power supply including a DC power supply, a switching element, and a discharge capacitor, wherein the discharge capacitor and the DC power supply are configured to be connected with each other and to be disconnected; a voltage detection unit disposed between the wire electrode and the workpiece; and a numerical controller, wherein the numerical controller includes a storage unit storing, in advance, a voltage value assumed when a dielectric breakdown occurs between the wire electrode and the workpiece, wherein the numerical controller is configured to compare a detected voltage value detected by the voltage detection unit with the voltage value stored in the storage unit, and wherein the numerical controller is configured to, as a result of the comparison, when the detected voltage value is smaller than the voltage value stored in the storage unit,