Method of and apparatus for wire-cutting a workpiece by electroerosion

摘要

An improved method of and arrangement for threading a wire electrode through a workpiece in a wire-cutting electroerosion machine having a continuous wire electrode axially transported from a supply means to a collection means along a predetermined wire guiding path; a pair of machining guide members disposed at opposite sides of the workpiece in the path for spanning the axially running wire electrode straightforwards thereacross through the workpiece and cutting feed means for displacing the workpiece relative to the axially running wire electrode transversely to the axis thereof along a prescribed feed path to form a desired electroerosion cut in the workpiece. The method comprises: forming a straight through-hole in the workpiece at a preselected location thereof representing a start point of the said prescribed feed path; positioning a wire electrode having a straightened broken end continuous from the supply means through the first of the said machining guide members disposed at an inlet side of the workpiece to locate the said broken end ahead of the workpiece; positioning the workpiece to locate the axis of the through-hole in coincidence with the axis of the straightened broken end projecting from the first machining guide member; and advancing the wire electrode with the straightened broken end into and through the through-hole of the workpiece and through the second of the said machining guide members disposed at an outlet side of the workpiece.