| 主权项 |
1. A cutting insert, comprising:
an upper surface; a lower surface; a side surface; a cutting edge which is located along an intersection of the upper surface and the side surface, and comprises a major cutting edge, a flat cutting edge, and a minor cutting edge located between the major cutting edge and the flat cutting edge; an insert center axis defined by a line passing through a center of the upper surface and a center of the lower surface a land part located along the cutting edge on the upper surface; a rake face located between the land part and a central portion of a central part of the upper surface and having a rake surface angle defined as an angle formed between a line that in a sectional side view lays tangent to the rake surface, and a line that passes through the cutting edge that is orthogonal to the insert center axis,wherein
the land part comprises
a minor cutting edge land portion located correspondingly to the minor cutting edge, anda major cutting edge land portion located correspondingly to the major cutting edge, the minor cutting edge land portion is inclined downward toward a central part of the upper surface, and a first inclination angle (θ1) and a second inclination angle (θ2) are smaller than the rake surface angle, and the first inclination angle (θ1) is greater than the second inclination angle (θ2), where the first inclination angle (θ1) denotes an inclination angle of the minor cutting edge land portion on the basis of a first line (L1) passing through the minor cutting edge and being orthogonal to the center axis of the cutting insert, and the second inclination angle (θ2) denotes an inclination angle of the major cutting edge land portion on the basis of a second line (L2) passing through the major cutting edge and being orthogonal to the center axis, wherein the major cutting edge land portion is inclined downward toward the central part of the upper surface. |
