摘要 |
In the electrical discharge machining of the surface of a recess in a workpiece electrode to a shape corresponding to that of a tool electrode, the electrodes are relatively displaced, during a finishing phase of machining, along an axis of penetration and simultaneously in a plane perpendicular to the axis of penetration with a cyclic translational movement whose amplitude increases with the penetration of the tool in the workpiece. This provides a virtual three-dimensional dilatation of the tool as it advances, and enables control of the sparking in both the frontal and lateral parts of the machining zone. The cyclic translational movements are obtained from a rotatable shaft having an axis parallel to the axis of penetration and an eccentric member cooperating with the rotatable shaft to slide relative to the shaft in a direction forming a predetermined angle with the direction of penetration, the eccentric member being rotated in unison with the shaft about its axis. |