Wire electrical discharge machining apparatus

摘要

An upper guide and a lower guide are respectively disposed above and below a workpiece. The upper guide and the lower guide respectively has wire guides for guiding the wire electrode. A pair of electric supply dies are respectively provided in the upper guide and the lower guide and are adapted to come into contact with and energize the wire electrode. An internal nozzle and an external nozzle are provided in at least one of the upper guide and the lower guide. A first piping system supplies the working fluid to the internal nozzle and a second piping system supplies the working fluid to the external nozzle, where the second piping system is independent of the first piping system. The working fluid having lower temperature and higher pressure than the working fluid jetted out and supplied from the external nozzle is jetted out and supplied to the workpiece from the internal nozzle.