| 摘要 |
PROBLEM TO BE SOLVED: To provide a drill with an extra-high pressure sintered body chip being the drill constituted by arranging the extra-high pressure sintered body chip in a cutting blade part, capable of cutting a chip into pieces over the whole length of the cutting blade even in the direction of length securely while cutting the chip into pieces in the direction of its width by providing the cutting blade with nicks. SOLUTION: A plurality of cutting blades 9 extending from the outer periphery of a tip of a drill main body 1 toward an inner peripheral side are formed at an interval in the peripheral direction on the extra-high pressure sintered body chip 8 arranged in a tip part of the drill main body 1 rotated around an axis 0. The recessed groove-like nicks 10 are formed on these cutting blades 9 so as to deviate rotation locus around the axis 0 by the cutting blades 9 being adjacent to each other in the peripheral direction to apply honing 11 having a narrower width on an outer peripheral side of the cutting blade 9 than the width on an inner peripheral side. COPYRIGHT: (C)2007,JPO&INPIT
|
