GB1504742A - Electro-erosion - Google Patents

Abstract

1504742 Electro-erosion CAREL FOUCHE LANGUEPIN 11 Feb 1975 [21 Feb 1974] 5835/75 Heading B3V [Also in Division G3] In a process of electro-erosion, the electrode feed rate is measured and regulated to an optimum value by adjusting the power delivered to the working gap by a supply generator. The gap voltage is also regulated by controlling the electrode feed motor in dependence upon a comparison of the actual gap voltage with a reference voltage. As shown in Fig. 1, a motor 12 drives an electrode 5 machining a workpiece 6. A generator 10 supplies a working voltage. The gap voltage is sensed by conductors 13, 14 and compared in an amplifier 15 with a reference voltage from a potentiometer 16. A resultant error signal 18 is fed to the motor 12 which operates to maintain the gap voltage and width constant. The error signal 18 is also fed to an integrator 19, the output voltage of which represents the feed rate of the electrode 12. A desired feed rate is represented by the setting of a potentiometer 20. The voltages from the integrator 19 and the potentiometer 20 are compared in a circuit 21 supplying a control signal to a servomotor 22 which adjusts the power supplied by the generator 10, thereby controlling the rate of erosion of the workpiece 6 and regulating the electrode feed rate. In a modification, Fig. 2, the error signal 18 drives both the electrode motor 12 and an auxiliary motor 26 connected to a tachometric dynamo 27, the voltage from which represents the electrode feed rate and is supplied directly to the comparator circuit 21. Alternatively, an indication of the feed rate may be derived by differentiating the error signal and by photoelectrically counting pulses produced by a disc, the pulses being fed to a bidirectional counter, Fig. 4 (not shown).