| 摘要 |
<p>The cutting insert is provided with an insert main body, a cutting edge formed at a circumferential edge of the rake face of the insert main body to have a corner edge and two side edges arranged on the both sides thereof, a protrusion portion formed on the rake face, and a pair of convex portions formed so as to extend out to the side edges on both sides divided by a bisector of the corner edge from a wall surface of the protrusion portion to the rake face. Each of the pair of convex portions is provided with a first wall surface which extends so as to separate gradually from each other toward the cutting edge from the wall surface of the protrusion portion, and facing the corner edge of the cutting edge, and a second wall surface in contact with the first wall surface and continuing to both ends of the corner edge, facing the side edge. The first and the second wall surfaces incline toward the rake face as they extend away from a ridge line between the both wall surfaces. The ridge line is in contact with the wall surface of the protrusion portion at a position lower than the top portion of the protrusion portion closer to the corner edge. On the rake face closer to the corner edge than the pair of convex portions, a recess having a rear wall portion which extends so as to cross the bisector between the corner edge and the convex portion is formed.</p> |
