走査放電軸成形法における軸直径と消耗比

抄録

  In this study, we propose a new micropin forming method in which the forming plate can be stationary while the rotating electrode moves towards the forming plate. As the processing area in this method is large, a higher removal rate is possible compared with the WEDG micropin forming method. Forming by this method is easily accomplished for the micropins of less than 50 μm under a low electrical discharge conditions. In this study, we aimed to obtain the desired electrode diameter by means of scanning electric discharge machining. The electrode diameter decreased rapidly with increasing machining time, and it was difficult to control the micropin diameter by controlling only the machining time. Therefore, we conducted micropin forming by controlling the indicator scanning distance during machining. The results are strongly dependent on the ratio of consumption of the forming plate and the electrode. We investigated the relationship between the electrode diameter and the scanning distance referring to the experimental values and the theoretical ratio based on the consumption theory. Micropin diameters of up to 150 μm were obtained. The experimental values were found to be in good agreement with the theoretical values. Since the wear ratio was changed owing to the miniaturization of the electrode, there is a difference between the theoretical and experimental values.