US 12,030,128 B2
Cutting insert and cutting edge replacement type cutting tool
Masashi Kanbara, Tokyo (JP); Jun Kitajima, Tokyo (JP); Chinami Sakamoto, Tokyo (JP); and Shota Watanabe, Tokyo (JP)
Assigned to MITSUBISHI MATERIALS CORPORATION, Tokyo (JP)
Appl. No. 17/270,645
Filed by MITSUBISHI MATERIALS CORPORATION, Tokyo (JP)
PCT Filed Aug. 27, 2019, PCT No. PCT/JP2019/033528
§ 371(c)(1), (2) Date Feb. 23, 2021,
PCT Pub. No. WO2020/045438, PCT Pub. Date Mar. 5, 2020.
Claims priority of application No. 2018-161805 (JP), filed on Aug. 30, 2018; and application No. 2018-161806 (JP), filed on Aug. 30, 2018.
Prior Publication US 2021/0339321 A1, Nov. 4, 2021
Int. Cl. B23C 5/20 (2006.01)
CPC B23C 5/202 (2013.01) [B23C 2200/0411 (2013.01); B23C 2200/203 (2013.01); B23C 2200/291 (2022.02); B23C 2200/369 (2022.02)] 13 Claims
OG exemplary drawing
 
1. A cutting insert comprising:
a polygonal plate-shaped insert main body that includes first and second polygonal surfaces facing opposite to each other and a plurality of side surfaces which are disposed in a vicinity of the first and second polygonal surfaces,
wherein a corner edge that has a corner rake surface on the first polygonal surface exists at a first corner portion among corner portions of the first polygonal surface of the insert main body,
from the corner edge to a second corner portion adjacent to the first corner portion in a circumferential direction of the first polygonal surface, a main cutting edge that has, on the first polygonal surface, a main rake surface connected to the corner rake surface and extends from a first end portion of the corner edge, and
the main cutting edge includes, at least on a corner edge side, a rake angle gradual increase region where a rake angle of the main rake surface gradually increases as going from the first end portion of the corner edge toward a second corner portion side,
wherein the rake angle gradual increase region is within a range of 1.0 mm to 2.0 mm from the first end portion of the corner edge in plan view facing the first polygonal surface, and the rake angle of the main cutting edge is constant within a range exceeding the first end portion of the corner edge by 2.0 mm.