Research On High Efficient Blanking Wedm Pulse Generator

Efficient blanking of thick and difficult-to-process materials has become aproblem demanding urgent solutions to in aerospace, military industry and molding.The problem becomes more serious when it comes to blanking on the complexsurface. This thesis puts forward efficient Wire-EDM blanking method, focuses onits core technique, the technique related with Wire-EDM pulse generator, andexplores effective methods to enhance the processing efficiency of Wire-EDM pulsegenerator in blanking.In the beginning, based on the mechanism of Wire-EDM and factorsinfluencing the Wire-EDM efficiency, this thesis puts forward methods ofenhancing the efficiency of pulse generator, including increasing peak current andselecting appropriate parameters like pulse width and gap. According to themethods of enhancing processing efficiency, main circuit with multiple-parallelpower switch is adopted and solves the problem about conduction frequency ofsingle power switch. It also solves the problems of safety and stability caused bysingle power switch working with heavy current. Based on AT89C51SCM andcomplex programmable logic device (CPLD), logical sequential pulse signal is built,which meets the requirement of processing according to preset value. Meanwhile,adjustment to peak current can conduct based on different processing techniques.With the help of power amplifier circuit that has been built, pulse signal can stablydrive power switch. High-speed sampling of gap voltage can conduct with PICSCM. Several results of the samples are calculated and sent to the upper computerthrough serial communication module, so that the upper computer makes real-timejudgment on the condition of gap discharge.In the last part, feasible analysis are employed on the efficiently blankingWire-EDM pulse generator developed in this thesis. First, analysis is done on pulseshapes of circuits at all levels from pulse generator. It turns out that the indexes ofpulse shapes at all levels meet the needs of design. Second, comparative experimentis carried out between the built pulse generator and traditional high-speedWire-EDM pulse generator, The result shows that efficiency is apparently enhanced by efficiently blanking Wire-EDM pulse generator, which has advantage especiallywhen the workpiece is thick. Finally, the gap of pulse generator and the quality ofworkpiece’s surface are analyzed. It draws the conclusion that efficiently blankingpulse power can meet the requirement of efficiently blanking.