| 摘要 |
PROBLEM TO BE SOLVED: To provide a drill head for deep boring devised to improve working precision while improving roundness and straightness of a bored hole. SOLUTION: This drill head for deep boring is constituted by respectively fixing a cutting blade 2 on the tip end surface side of a head body 1 and guide pads 3, 4 on the outer peripheral side of the tip end part of the head body 1, wherein length Lm in the axial direction of a margin part 6 formed on the tip end side in the drill rotating direction of an outer peripheral part of the cutting blade 2 and length Lp in the axial direction of the guide pads 3, 4 are made substantially the same, and a tip end position and a rear end position of the margin part 6 and a tip end position and a rear end position of the guide pads 3, 4 are respectively and substantially aligned in the circumferential direction. COPYRIGHT: (C)2007,JPO&INPIT |
