| 摘要 |
PURPOSE:To perform electric discharge machining for a machined surface with small roughness, by connecting an inductance element and damping resistor to the output of a switching circuit in the power source for an electric discharge machining pulse. CONSTITUTION:An electric discharge machining power circuit 1 is os such constitution that a DC power source 4 is connected to a switching transistor 3 through a resistor 5 and the switching transistor 3 is controlled in pulse width by a controller 2. Between an electrode 6 and work 7 and the switching circuit, there is connected a parallel circuit consisting of an air-core coil 8 and damping resistor 10. Inductance of the air-core coil 8 can be adjusted by taps 8a-8d to smooth a rise-up characteristic of pulse voltage as shown by dotted lines. It is preferably to arranged values such as at most 10mus for pulse width, at least 150V for power voltage and at least 3muH for inductance. In this way, electric discharge machining work for small surface roughness can be performed. |
