WIRE ELECTRIC DISCHARGE MACHINE FOR DETECTING MACHINING STATE AND DETERMINING AVERAGE VOLTAGE BETWEEN POLES

摘要

PROBLEM TO BE SOLVED: To provide a wire electric discharge machine capable of determining average voltage dependent on a correct machining state, and of correctly controlling a feed speed and the like of an electrode according to a machining state.SOLUTION: A machining power source 4 includes a DC voltage source 41, a high speed switching device 42 constituting a bridge circuit, a voltage application series resistance 43, and applies machining power source output to between poles via a power feeding line 5 and a power feeding part 6 by a command from a machining power source control device 8 controlled by a numerical controller 9. A machining state detection device 7 detects voltage generated between poles, determines data on the number of cycles of voltage application (q), the number of open-circuits (r), the number of discharge (s), and the number of short-circuits (w) per unit time by a machining state determining circuit from detected voltage generated between the poles, and sends the data to the numerical controller 9. On the basis of data on q, r, s, w per unit time sent from the machining state detection device 7, the numerical controller 9 controls a servo drive device 10 for driving servo motors 3a, 3b.