抄録
In 2nd report we described that it was possible to detect a discharging position from discharging current waves or time differential current waves on WIRE EDM.
In 3rd report we analyzed detecting characteristics considering a skin effect in electrode and workpiece for Die sinking EDM and WIRE EDM which had two branched discharging circuits.
Analytical results showed that a shape of gap voltage wave, a discharging pulse duration and loop currents which remained after discharging not only in the branched circuit but also in the electrode and the workpiece, caused detecting errors. To avoid these errors we proposed a new detecting method in which the discharging position was detected from a voltage drop between two branched points on workpiece, but was regularized by a voltage drop on a thick and U-type shunt.
In this report, at first we describe some analyticaly obtained results to decrease the effect of the shape of gap voltage wave, the discharging pulse duration and the loop current for the detection of discharging position from the current wave or the time differential current wave.
Next we describe experimental results in which the discharging position is detected from the time differential current wave.
Finally we describe experimental results in which the discharging position is detected from the voltage drop in workpiece regularized by the voltage drop on U-type shunt. Results show that the detecting accuracy of this method is fine.
