Patent ID: 6698639
Filing Date: 2004-03-02
Classification: B23H

Abstract:
An automatic wire feeder of a wire electric discharge machine in which electric discharge is generated between a traveling wire electrode and a workpiece to machine the workpiece by electric discharge energy, comprising:a feed roller for feeding the wire electrode; a slider block supported movable up and down; a guide pipe fixed to the slider block, the guide pipe for guiding the wire electrode; a hollow member fixed to the slider block, an outer diameter of the hollow member reduced in a wire feed direction; and a pressurized gas supply means for supplying pressurized gas toward the outer diameter of the hollow member, wherein a forward end section of the hollow member is inserted into an inner diameter section of an upper section of the guide pipe while a predetermined overlapping length is kept, the predetermined overlapping length at which a thrust of the wire electrode has a local maximum value or a value of substantially the local maximum value; a predetermined clearance is formed between the inner diameter of the guide pipe and the outer diameter of the forward end section of the hollow member; and a thrust is given to the wire electrode when pressurized gas supplied by the pressurized gas supply means flows in the guide pipe via the clearance.