TOOL-POSITIONING METHOD, TOOL-POSITIONING DEVICE AND POWER FEEDER FOR TOOL POSITIONING

摘要

A power feeder (10) includes a flexible strip (12) having a conducting front side (12a) and an insulating back side (12b); a retainer unit (20) for holding the strip wrapped on a bar (18) with the back side being in close contact with the bar; a feeder unit (22) connected electrically with the front side of the strip; and a base (26) mounted detachably on the headstock (24) of an automatic lathe. A tool-positioning device (14) including this power feeder includes a driving unit (60) for bringing a tool (56) to be positioned into contact with the front side of the strip; a section (62) for detecting a conduction between the tool and the front side of the strip through the feeder unit to determine the position of contact with the tool; and a corrective processing section (64) for determining the position of a center axis (18a) of the bar based on the position of the determined position of contact with the tool and properly correcting the machining position data preset for the tool in accordance with the determined position of the center axis. The tool does not directly touch the bar, so that the surface of the bar and the tool itself are protected from damage.