Method and apparatus for restoring a wire electrode

摘要

A method and apparatus for restoring a broken wire electrode in a wire electrode-type electric discharge machine for machining a workpiece into a desired shape while the workpiece is moved relative to the wire electrode on the basis of machining command data. For effecting the restoration of the wire electrode, memory means are provided for storing the relative machining starting position of the workpiece and the wire electrode at the machining starting point, and the relative wire electrode breakage position of the workpiece and the wire electrode when the wire electrode breaks. After the wire electrode breaks the relative position of the workpiece and the wire electrode is brought into coincidence with the machining starting position on the basis of information indicative of the machining starting position and the wire electrode breakage position. After the wire electrode is returned to a feed system therefor, the workpiece is again moved relative to the wire electrode from the machining starting point on the basis of the machine command data. The relative position of the workpiece and the wire electrode is made to coincide with the wire electrode breakage position, after which the discharge machining operation is resumed.