Wire electrical discharge machining apparatus and control method for wire electrical discharge machining apparatus

A control method for a wire electrical discharge machine configured to perform electrical discharge machining on a workpiece by applying a voltage to an inter-electrode gap between a wire electrode and the workpiece and thereby generating an electric discharge while causing the wire electrode to be moved with respect to the workpiece,

• wherein the wire electrical discharge machine comprises a voltage detection unit configured to detect a voltage in the inter-electrode gap,
• the control method for the wire electrical discharge machine comprising:
• a first machining condition setting step of setting a machining condition to a first condition in a case that the wire electrode is approaching a machining end surface of the workpiece in order to machine the workpiece;
• a first control step of controlling, in accordance with the first condition, a relative speed of the wire electrode with respect to the workpiece, and an electric discharge energy generated in the inter-electrode gap;
• an electric discharge determination step of, in the case that the wire electrode is approaching the machining end surface, determining, for each unit time period, whether or not the electric discharge has occurred in the inter-electrode gap within the unit time period, based on the voltage in the inter-electrode gap that has been detected;
• a counting step of counting a number of times that it is determined that the electric discharge has occurred;
• a second machining condition setting step of setting the machining condition to a second condition that differs from the first condition, in a case that the counted number of times has reached a predetermined number of times;
• and
• a second control step of controlling, in accordance with the second condition, the relative speed of the wire electrode with respect to the workpiece, and the electric discharge energy generated in the inter-electrode gap.