Patent ID: 6907311

Claim:
An electric discharge machining apparatus comprising: a machining tank in which a workpiece is placed for machining; a machining unit that has an electrode for electric discharge machining of the workpiece; a power supply unit that supplies a voltage between the electrode and the workpiece; a numerical control unit that controls the machining unit and the machining tank, according to a machining program for electric discharge machining of the workpiece; an input unit for inputting shape of the electrode, shape of the workpiece, and a machining depth to which the workpiece is to be machined; a simulation unit that calculates machining information relating to the machining shape at each simulated machining depth, when the workpiece is machined with the electrode to a predetermined depth, until the machining depth input is reached, based on the shape of the electrode, the shape of the workpiece, and the machining depth of the workpiece, and determines the shape obtained by subtracting the machining shape simulated from the shape of the workpiece, as a new shape of the workpiece, at each simulated machining depth; and an output unit that outputs a list of data rows, each data row having the simulated machining depth and the machining information corresponding to the simulated machining depth.