CUTTING INSERT AND INDEXABLE INSERT-TYPE CUTTING TOOL

摘要

A cutting insert and an indexable insert-type cutting tool includes a cutting edge (6A) formed on each of a pair of side ridge portions of at least one of the side faces, wherein an insert main body (1) is formed in the shape of having front-back inversion symmetry which is 180° rotationally symmetrical with respect to a line of symmetry (N) passing through the center of the side faces; a flank face adjacent to the cutting edge (6A) is formed on the side face in the vicinity of each of the pair of polygonal faces (2); each of the flank faces is formed in the shape of a twisted face; the pair of side ridge portions on which the cutting edge (6A) is formed intersect each other in such a manner that the second corner portion (B) of one side ridge portion protrudes outside the other side ridge portion.

主权项

1. A cutting insert which is attached in a detachable manner to an insert seat of an indexable insert-type cutting tool, the cutting insert comprising:
a polygonal plate-like insert main body having a pair of polygonal faces and a plurality of side faces arranged on the periphery of the pair of polygonal faces, wherein of the pair of polygonal faces, one polygonal face is used as a rake face and the other polygonal face is used as a seating face seated on a base of the insert seat; a cutting edge is formed on each of a pair of side ridge portions of at least one of the side faces, the pair of side ridge portions being a portion intersecting the side face and the pair of polygonal faces; the insert main body is formed in the shape of having front-back inversion symmetry which is 180° rotationally symmetrical with respect to a line of symmetry passing through the center of at least one of the side faces; on at least one of the side faces, a flank face adjacent to the cutting edge is formed on the side face in the vicinity of each of the pair of polygonal faces, when the pair of polygonal faces are used as rake faces; each of the flank faces is formed in the shape of a twisted face in which a flank angle with respect to the cutting edge gradually increases in a positive angle side while each of the flank faces becoming close to a second corner portion from a first corner portion, the first corner portion and the second corner portion being alternately located in a circumferential direction of the pair of polygonal faces in at least one of the side faces; and the pair of side ridge portions of the side face on which the cutting edge is formed intersect each other in such a manner that the second corner portion of one side ridge portion protrudes outside the other side ridge portion, when the polygonal face is viewed from the front thereof.