BURRLESS PROCESSING METHOD FOR HOLE AND DRILL USED IN BURRLESS PROCESSING

摘要

PROBLEM TO BE SOLVED: To provide a drilling method preventing a generation of a burr by shearing the burr while pulling up the burr by a twisted outer periphery part of the drill at a position where a cutting blade of the drill sufficiently exceeds the height of the burr by making lead-in of the drill large before the burr is pushed out and is not reversed upon penetration of the drill.;SOLUTION: In the burrless processing method for a hole for processing a through-hole on a work with an approximately flat back surface, a hole processing is carried out so that an outer peripheral corner part 2 of the cutting blade of the drill is positioned as primary cutting 5 to a depth of 0.005 × drill diameter or more to 0.15 × drill diameter or less from the bottom surface of the work. The drill is, as secondary cutting 6, penetrated to the position where the outer peripheral corner part of the cutting blade of the drill exceeds the burr 4 height at the feed rate of drill diameter × 0.2 or more to drill diameter × 1.4 or less per one rotation. The burr is sheared by pulling up the burr by an outer peripheral margin part of the drill as secondary cutting. The burrs at two positions pushed out at the time of penetration of the secondary cutting are completely removed.;COPYRIGHT: (C)2004,JPO