Discharge state identification and servo control method of high-speed reciprocating microwire-EDM

摘要

The electrical resistance of wire electrode increases with the decrease of the wire diameter. It is difficult to use the voltage threshold method to distinguish the spark and short-circuit states according to the discharge voltage, so it cannot meet the requirements of normal machining. In this study, a gap discharge state identification and servo control method based on discharge current are proposed in high-speed reciprocating microwire-EDM. The synchronous pulse can improve the stability of the system by reducing the disturbance of the discharge frequency and deionization. The experimental results show that a high wire speed is beneficial to the introduction of dielectric and the removal of erosion particles. When the target probability is set at 90%, the processing stability is higher. By using phi 0.08 mm molybdenum wire electrode, the stable cutting of a 1250 height-diameter ratio (the ratio of cutting height to electrode wire diameter) workpiece is realized with an average cutting efficiency of 32.08 mm(2)/min. This study is a useful exploration of the machining of high height-diameter ratio workpieces by using a microwire electrode in high-speed wire-cut electrical discharge machining (HSWEDM).