To provide a cutting-edge replaceable drill enhancing a discharge performance of cutting chips, and carrying out a processing stably with high accuracy.
The cutting-edge replaceable drill is equipped with: a drill body rotated around an axis O; and inserts 10 for cutting a material to be cut using blades 15 projected from the tip of the drill body. At least two inserts 10 are respectively disposed on an inner circumferential side and an outer circumferential side in a diameter direction to the axis O, and rotating trajectories around the axis O of the blades 15 of the inserts 10 are intersected with each other. A blade length extending from the point of intersection of the rotating trajectories to the inner circumferential side and allowing the blade 15 of the insert 10A on the inner circumferential side to cut a material to be cut, is set to be larger than a blade length of the blade 15 of the insert 10B on the outer circumferential side extending from the point of intersection to the outer circumferential side. The blade 15 of the insert 10A on the inner circumferential side is arranged on the front side in a rotating direction T to an imaginary plane SA including the axis O and parallel with the blades 15 when the drill body is seen from the front end side.
COPYRIGHT: (C)2011,JPO&INPIT
Tadashi Takahashi
Yasuhiko Murayama
Noriko Yanai