US 12,257,638 B2
Cutting insert, cutting tool and method for manufacturing machined product
Masahiro Yamamoto, Ritto (JP)
Assigned to KYOCERA CORPORATION, Kyoto (JP)
Appl. No. 17/287,993
Filed by KYOCERA CORPORATION, Kyoto (JP)
PCT Filed Oct. 18, 2019, PCT No. PCT/JP2019/041148
§ 371(c)(1), (2) Date Apr. 22, 2021,
PCT Pub. No. WO2020/085245, PCT Pub. Date Apr. 30, 2020.
Claims priority of application No. 2018-199365 (JP), filed on Oct. 23, 2018.
Prior Publication US 2021/0379678 A1, Dec. 9, 2021
Int. Cl. B23C 5/20 (2006.01); B23C 5/06 (2006.01)
CPC B23C 5/202 (2013.01) [B23C 5/06 (2013.01); B23C 2200/0494 (2013.01); B23C 2200/284 (2022.02); B23C 2200/367 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A cutting insert, comprising:
a first surface having a polygonal shape;
a second surface located on a side opposite to the first surface; and
a lateral surface located between the first surface and the second surface, wherein
along an outer peripheral edge of the first surface, the polygonal shape of the first surface comprises
a first corner,
a second corner located adjacent to the first corner,
a third corner located adjacent to the first corner,
a first side edge directly connecting to each of the first corner and the second corner, and
a second side edge directly connecting to each of the first corner and the third corner,
the first side edge is shorter than the second side edge,
the first side edge and the second side edge are configured to perform a cutting process of a workpiece,
the lateral surface comprises
a first lateral surface an entirety of which is flat and at least a part of which is located between the first side edge and the second surface,
a second lateral surface which is flat and at least a part of which is located between the second side edge and the second surface,
a first curved surface which is located between the first surface and the second surface,
a first connection surface extending from the first side edge, and
a transition surface extending from the first connection surface to the first lateral surface, the transition surface inclined outwardly with respect to the first connection surface in a front view of the first surface,
the entirety of the first lateral surface is located further outside than the first side edge and the first connection surface in the front view of the first surface,
the first lateral surface comprises a first region having a boundary located closer to the second lateral surface as the first region comes closer to the second surface,
the first region contacts the first curved surface,
an imaginary straight line passing through a center of the first surface and a center of the second surface is a central axis, a secondary central axis perpendicular to the central axis passes through a center of the first lateral surface, and the first lateral surface has 180-degree rotational symmetry about the secondary central axis,
the second lateral surface is located further outside than the second side edge in the front view of the first surface,
the second lateral surface comprises a second region located closer to the first lateral surface as the second region comes closer to the second surface,
the second region contacts the first curved surface,
a boundary between the first curved surface and the second region comprises an end portion closest to the first lateral surface compared with a remainder of the boundary,
the end portion is closer to the second surface than the first surface,
each of the first lateral surface and the second lateral surface is spaced apart from the first side edge and the second side edge, and
the first lateral surface and the second lateral surface are configured to contact a holder when fixing the cutting insert to the holder.