放電加工法の研究(第1報)

抄録

In boring technique of electric spark discharge performed on general iron plate by using brass as the working electrode and water as the working medium, effect of values of electric constant-d-c source voltage E, series resistor R and parallel capacitor C-on working speed and accuracy was examined. In case E, I_s and C are constant (I_s is short circuit current when the electrode is in contact and shows the magnitude of R), working speed has a maximum value in accordance with change of the working current. This maximum value varies proportionally to I_s and √E³, and when C is changed the speed decreases rapidly at less than 30μF and it is almost saturated at more than 100 μF. The cross sectional area of hole has no connection with the speed manifested by g/min. The higher the speed, the lower the accuracy becomes and vice versa. At less than 1A of I_s and at less than 10μF of C, the accuracy becomes rapidly higher and error larger linearly to E. In conclusion, maximum speed is practically about 2.0-2.5 g/min and minimum error is about 0.03-0.04 mm.