Electrical discharge machining electrode for forming minute holes in a workpiece and electrical discharge machining apparatus employing such an electrode

摘要

An electrode consisting of a core wire, a support tube having a bore in which the electrode core wire is slidably supported, an outer peripheral surface held in highly concentric relation to the bore, and a rotatable support body for transmitting rotative power to the support tube. The support tube and the rotatable support body having a central axis and a center of rotation are aligned with each other for preventing the electrode from having wobbling movement or displacement during rotation of the electrode. This allows minute holes of small out-of-roundness and good accuracy of shape to be formed. In addition for fine feeding of an electrode an apparatus is used which includes a gear rotated by a motor to vertically move a feed screw that causes a pivot lever to move the electrode for a small vertical interval.