US Patent No. 9,364,909

WIRE ELECTRIC DISCHARGE MACHINE AND WIRE ELECTRIC DISCHARGE MACHINING METHOD


Patent No. 9,364,909
Issue Date June 14, 2016
Title Wire Electric Discharge Machine And Wire Electric Discharge Machining Method
Inventorship Yasuo Hasegawa, Yamanashi (JP)
Assignee FANUC CORPORATION, Yamanashi (JP)

Claim of US Patent No. 9,364,909

1. A wire electric discharge machine configured to apply a voltage to a machining gap between a wire electrode and a workpiece
so that the workpiece is machined by electric discharge, the wire electric discharge machine comprising:
a power supply device for electric discharge machining comprising a plurality of DC power supply devices, supply voltage switching
means for changing the plurality of DC power supply devices, and current supply means for turning on and off the supply of
a discharge current to the machining gap from the DC power supply device changed by the supply voltage switching means; and

a controller configured to control the supply voltage switching means and the current supply means of the power supply device
for electric discharge machining, adjust the magnitude and the pulse width of a pulse voltage applied to the machining gap,
and adjust a peak current value of a total discharge current flowing to the wire electrode and the current pulse width within
ranges of 30 to 150 amperes and 0.3 to 6.4 microseconds, respectively,

the wire electric discharge machine being configured, when the material of the workpiece is graphite or a carbon composite,
to give a command from the controller to the supply voltage switching means, adjust the pulse voltage applied to the machining
gap and the pulse width of the pulse voltage, give a command from the controller to the current supply means, set the peak
current value of the total discharge current flowing to the wire electrode and the current pulse width so as to be suitable
for machining of the graphite or carbon composite material, and perform the machining with a gentle rise of a machining current,
the peak current value reduced, and the current pulse width increased.