Process and apparatus for electrical discharge machining of cylindrical work

摘要

Disclosed are a process and apparatus for subjecting the outer surface of a satinizing roll to electrical discharge machining to produce a satin-like roughened surface of a uniform roughness. With this electrical discharge machining process, the electrical discharge machining speed of a plurality of electrodes mounted on a plurality of head columns is held lower than a steady state working speed until the electrodes on all the head columns start discharging, and in response to the detection of the discharge of every electrode on the head columns the working speed is changed to the steady state working speed and the head columns are simultaneously moved traversely along the axis of rotation of a cylindrical work, thus preventing the occurrence of a difference in the depth of erosion or stepped portions on the surface of the work during the initial working period. The apparatus for performing this electrical discharge machining process comprises a working power source including means for controlling the working speed, and detecting means for detecting that every electrode has started discharging so as to direct the working power source to change the working speed and so as to simultaneously actuate a head column transverse feed unit.