Patent ID: 7168893
Filing Date: 2007-01-30
Classification: B23B,Y10S,Y10T

Abstract:
1. A throw-away tipped drill comprising: a throw-away tip of approximately a flat plate shape; a cutting edge formed upon an edge of said throw-away tip; said throw-away tip engaged to a concave groove shaped tip attachment seat which opens at an end surface of a drill main body which rotates around an axial line so as to divide the end portion of said drill main body into two portions; said drill main body having a pair of outer side surfaces respectively confront a pair of internal side surfaces of said tip attachment seat; a clamp bolt inserted into a through hole provided at an end portion of said drill main body so as to intersect said tip attachment seat: wherein a slit which extends towards the rear end of said axial line direction is formed upon the bottom surface of said tip attachment seat which faces towards the end of said axial line direction, and, when viewed from the end of said axial line direction, at the end portion of said drill main body which is divided into two by said tip attachment seat; said slit is arranged as being displaced so as to be closer to a portion into which a shaft portion of said clamp bolt is threaded than to a side which is pressed by a head portion of said clamp bolt; and when seen from the end of said axial line direction, an angle of intersection between the direction of extension of said slit and the direction of extension of said clamp bolt is inclined from 90° by an angle β, where 0°<β≦15°).