ワイヤ放電加工の加工精度に関する基礎的研究

第1報, 荒加工の溝幅とワイヤ振動振幅, ギャップの関係

抄録

In this series reports, we deal with accuracy of Wire EDM from rough cutting to finish cutting discussing about reasons of spoiled precisions.
In this first report, we investigate about the relation between cut groove width, wire vibration amplitude and gap length of the rough machining, and also about the relation between them and some EDM conditions.
The wire vibration amplitude is measured with a optical fiber-slit detecting system. The gap length is calculated from ignition delay time using an experimentally obtained relationship between the ignition delay time and the gap length for a single discharge. The ignition delay time is calculated from mean working voltage and other EDM conditions.
Results shows that the cut groove width is the sum of the wire diameter, the wire vibration amplitude and the double of gap length. The wire vibration amplitude is proportionally increasing with discharge frequency from the value of wire vibration amplitude caused by a single discharge, and also increasing with the gap length.
It is clarified that the cut groove width is less sensitive to OFF duration of discharging pulse if the mean working voltage was used for a servo feed back system or if the mean working voltage was constant, because the increasing of gap length cancels the decreasing of wire vibration amplitude when the OFF duration was increased.