Patent ID: 9308546
Filing Date: 2016-04-12
CPC Classification: B05C,H01J,H05H

Claim Text:
1. A discharge surface treatment apparatus that: generates a pulsed discharge between poles comprising a discharge electrode and a workpiece, wherein the discharge electrode is obtained by compression-molding of any one of a metal powder, a powder of a metal compound, and a powder of ceramics or a mixture thereof; and forms a film made of an electrode material on a workpiece surface by thermal energy due to the discharge, the apparatus comprising: a capacitor that is connected to any one of the discharge electrode and the workpiece at one end; a switching element connected between a power supply and the workpiece; a controller configured to turn on the switching element to apply a voltage between the poles and charge the capacitor with a power supplied from the power supply; and a parallel circuit of a resistor and a diode, which is provided between another one of the discharge electrode and the workpiece and another end of the capacitor via a connection line, wherein the capacitor is configured to generate a leading pulse current having a high peak value and a short pulse width; and the resistor is configured to suppress, and the diode is configured to block, a reverse current occurred in the capacitor from flowing toward the poles, when a subsequent current having a low current value and a long pulse width starts flowing between the poles.