Cutting Tool and Cutting Insert Having Exactly Three Cutting Portions Therefor

摘要

In a cutting tool having an indexable cutting insert with three cutting portions, the cutting insert is removably securable to an insert holder by means of a fastener. The cutting insert has two opposing end surfaces with a peripheral side surface extending therebetween. At least one end surface has a central boss protruding therefrom with a raised support surface, and the peripheral side surface has three abutment recesses. In an end view of the cutting insert, each of the three abutment recesses is visible and located inside a first imaginary circle circumscribing the visible central boss. A holding portion of the insert holder has a seating surface with at least one protuberance protruding therefrom. The support surface is in clamping contact with the seating surface, and exactly two of the three abutment recesses are engaged with the at least one protuberance.

主权项

1. An indexable cutting insert (20) comprising:
two opposing end surfaces (22) with a peripheral side surface (24) and a central axis (A1) extending therebetween, a median plane (M) located between the two opposing end surfaces (22), exactly three cutting portions (26), each cutting portion (26) having a major cutting edge (30) extending from one end surface (22) to the other end surface (22), and a central boss (36) protruding from each of the two opposing end surfaces (22), wherein each central boss (36) has a raised support surface (38) located axially further away from the median plane (M) than any point on the three major cutting edges (30) located on the same side of the median plane (M), wherein each of the three major cutting edges (30) is formed by the intersection of a rake surface (32) and a clearance surface (34), and wherein the rake and clearance surfaces (32, 34) are located on the peripheral side surface (24), wherein each of the three cutting portions (26) has a radial plane (P1) containing the central axis (A1) and a first point (N1) on its respective major cutting edge (30), and wherein in an end view of the cutting insert (20), at least a portion of the rake surface (32) of each cutting portion (26) is located on the same side of its respective radial plane (P1) as the adjacent clearance surface (34).