Edm Small Hole Drilling Status And Power

As an important branch of micro-machining technology, micro-EDM has found its wide applications in industry for its untouched machining process, machining surface with high aspect ratio easily and high capability in machining micro 3D structure. Compared with normal EDM, in micro-EDM the electrical power used has to be small for micro machining, say 10-7-10-6J, and the frequency of discharging pulses has to be high, as high as up to 1Mhz or even higher. Thus, the gap state distinguishing method with higher reliability and the micro-energy pulse generator are proposed in micro-EDM's key technologies.High frequency and small electric power of micro-electrical discharge machining (Micro-EDM) cause the waveforms of voltage and current highly distorted, thus indistinguishable by the commonly used EDM distinguishing methods. Upon such knowledge of this, a new method is presented in this paper, where the fuzzy logic rules are used to combine the complementary signals from voltage and current taken as the two inputs to the fuzzy system and deduce a value in a range representing the discharging state of the sampling point. Learning Vector Quantification (LVQ) neural network architecture is adopted to convert this value of the sampling point deduced from the fuzzy system to the corresponding discharging state vector. After the statistical generalization of the points in a set of pulses, the ratio between the elements in the vector clarifies the discharging state of the gap between electrode and workpiece. The results show that this method is operated well, impoving the reliability of the state discrimination and the machining performance.Based on the identification of discharging gap, the pulse power supply configuration is presented in the paper, which has the monitoring circuit for gap voltage and current, the discharging parameters regulator. The circuit topology, operation principle, control scheme and parameters design are discussed in detail.