Wire electric spark machining device

Abstract

Abstract PURPOSE:To enable easy sensing of abnormal wear of electricity feeders of a wire electrode by winding a current supply wire to an upper and a lower electricity feeders on a toroidal core, and sensing which unequilibrium current is greater, upper or lower, through discrimination of the phase of voltage output from a detection winding on said toroidal core. CONSTITUTION:To sense unequilibrium portion of the current supplied to an upper 3 and a lower 4 electricity feeder, windings 8, 9 to the upper and lower feeders 3, 4 are wound in such a way as offsetting the fluxes as a toroidal coil using a ferro-core having a high permeability even with high frequencies such as soft ferrite MOFe2O3 (M: two-value metal). Further a detection winding 10 is wound on toroidal core 7a. In this detection winding 10, an unequilibrium voltage V0 is generated, which is proportional to the unequilibrium current of the supply wires 8, 9 to the upper and lower electricity feeders 3, 4, and discrimination of the polarity of this unequilibrium voltage V0 serves to know which is greater, either the feeder current IUP flowing in the upper electricity feeder 3 or the feeder current IDW flowing in the lower electricity feeder 4. Thus digital sensing is provided to know which wear is greater, on upper or lower feeder.

Inventors

• 👤 Kazuo Tsurumoto
• 👤 鶴本　和夫

Bibliographic Details