Patent ID: 9409246
Filing Date: 2016-08-09
CPC Classification: B23H

Claim Text:
1. A wire electric discharge machining apparatus comprising: a work tank that is filled with a machining fluid and in which a machining of a workpiece is performed; a machining-fluid supply device that supplies the machining fluid to the work tank; a cooling device that cools the machining fluid; a cooling control device that controls a fluid temperature of the machining fluid by controlling the cooling device; a post-cooling temperature sensor that measures a temperature of the machining fluid as of leaving the cooling device as a post-cooling fluid temperature; and an intra-tank temperature sensor that measures a temperature of the machining fluid in the work tank as an intra-tank fluid temperature, wherein the cooling control device includes a first temperature-feedback control unit that feeds back the post-cooling fluid temperature into a cooling instruction value that is an instruction value for causing the cooling device to cool the machining fluid to a predetermined temperature, and a second temperature-feedback control unit that is arranged outside the first temperature feedback control unit and adjusts the cooling instruction value by feeding back the intra-tank fluid temperature to cause the intra-tank fluid temperature to follow a target temperature.