Plate-capacitor Model of Electrical Discharging Machining Process Based on Field Electron Emission Theory and Its Parameters Analysis

Based on the field emission theory,a plate-capacitor model is constructed to describe the electrical discharging machining(EDM) process.In this model,the discharging pulse period is divided into four stages,successively as the establishment of the interelectrode electrical field,the formation of the interelectrode discharging channel,the stable EDM and deionization,and the correlative parameters of each stages,such as the intensity of interelectrode electric field,the mean free path of interelectrode electrons,the interelectrode medium constant,and the varying rules of discharging current etc.,are analyzed.The distribution of EDM energy and its influencing factors are discussed,and the simulation methods of interelectode voltage and current based on this model are given in details.For the purpose of single factor analysis,a set of through-hole experiments and real-time measuring circuit are designed and carried.The good agreement of experimental results with simulation data and the fact that the model can well explain the differences of machining efficiency with tool pole and different machining parameters,demonstrate that the model is reasonable and effective.