Patent ID: 8642915
Filing Date: 2014-02-04
Classification: B23H

Abstract:
1. A wire electric discharge machining apparatus that generates electric discharges between a wire electrode and a workpiece and moves the wire electrode and the workpiece relative to each other, to perform discharge machining on the workpiece, the apparatus comprising: a corner speed controller configured to calculate and control a machining speed for each wire center trajectory in a corner portion according to an amount of machining estimated for the corner portion, wherein the wire electrode is moved on the wire center trajectory which is offset from a programmed trajectory with a different offset amount during each of machining stages; and a machining-condition correcting unit configured to correct machining conditions in each of the machining stages based on a circular arc radius of the programmed trajectory, with respect to machining according to the machining speed calculated by the corner speed controller, wherein the machining stages correspond to machining passes performed in finish machining of the workpiece, and the programmed trajectory is a desired projected machining shape to be obtained after a final machining pass of the corner portion is completed.