Fundamental Research On Compound Feeding Precision ECM Of Nozzle Taper Hole

Taper holes are widely applied in the key parts such as engine blade, automobile nozzle and spinneret. The machining quality and accuracy of taper hole have a great effect on the performance of the parts. Efficiency and precision processing of the parts above is difficult to realize by most processing methods as most of them are manufactured by difficult machining material and they are in the deep and narrow channels. Electrochmical machining is suited for taper hole processing as its advantages such as high efficiency, high surface quality, cathode lossless and no cutting force. Small gap machining is an effective method to improve the machining accuracy but it has not been widely applied because the machining products discharge and the electrolyte renew in the small gap are difficult.Focus on the ECM of taper hole, different process schemes for the taper holes of different tapers are made and experimental research of compound feeding ECM for the swirl chamber of nozzle is carried out. The primary research contents including:1. Process schemes design. ECM Process schemes for the taper holes of different tapers are designed according to the structure characteristics and process difficulties. Based on the analysis of factors influencing the accuracy of shaped cathode ECM, theoretical research on the influence of compound feeding to ECM is carried out. The key technology of the process research in taper hole ECM is summarized.2. Design and optimization of cathode. Based on the structure of nozzle swirl chamber, different cathode structures including truncated cone cathode and cone cathode are designed. To optimize the cathode structure, simulation analysis on flow field and electric field and comparison experiments are carried out.3. Fundamental experimental research. Based on the structure of nozzle swirl chamber, test piece and fixture are designed. To optimize the import pressure, export pressure and cathode motion, simulation analysis on the velocity and pressure distribution of electrolyte in the gap are carried out. According to the fundament process experiments, influences of different amplitudes, frequencies and cathode feeding speeds to the aperture and taper are analyzed. Finally optimized process parameters are achieved and high precision taper holes are steady processed.The research above is an effective exploration to the precision and efficiency ECM of parts with taper holes and a systematic research to the ECM of typical taper hole with large taper. The study above is of great significance to the manufacture of parts with taper holes and the improvement of ECM accuracy.