The influence of planetary movement of tool electrode on bubble flushing effect in micro hole drilling with EDM

抄録

In micro EDM drilling, the deteriorating environment due to debris contamination leads to the decrease of machining speed and bad machining accuracy. Improving the debris evacuation by enhancing the bubble flushing effect is a common method, like the planetary movement of tool electrode and ultrasonic vibration applied in the dielectric. However, the mechanism still lacks obvious evidence why improving the flowing of dielectric in the interelectrode gap can enhance the efficiency of debris evacuation. In this report, the influence of planetary movement of tool electrode on bubble flushing effect is investigated through quantitatively estimating bubbles captured by a high-speed camera. The results show that lots of small bubbles appear and the exchange of dielectric is largely improved. The reason is because: first, the change of side gap results in the discharge in side gap; second, the large bubble can be forcibly separated by the tool in planetary movement and becomes small bubbles. Therefore, the nature of planetary movement of tool electrode is attributed to the change of bubble state in interelectrode gap.