Cutting insert and indexable cutting tool

Patent metadata

Field	Value
Publication number	US-11045886-B2
Application number	US-201716068684-A
Country	US
Kind code	B2
Filing date	Jan 12, 2017
Priority date	Jan 13, 2016
Publication date	Jun 29, 2021
Grant date	Jun 29, 2021

Abstract

A cutting insert has an insert major body which includes two hexagonal faces facing each other and six side faces arranged around the two hexagonal faces, and is rotationally symmetrical at 120° intervals about an insert center line passing through centers of the two hexagonal faces and inversely symmetrical in front and back with respect to the two hexagonal faces, wherein a major cutting edge and an minor cutting edge are alternately formed in a circumferential direction in the single hexagonal face at twelve intersecting ridgeline portions at which the hexagonal faces and the side faces intersect, the major cutting edge is formed to be located at an intersecting ridgeline portion with one hexagonal face while the minor cutting edge is formed to be located at an intersecting ridgeline portion with the other hexagonal face at a single side face.

First claim

The invention claimed is:

1. A cutting insert comprising:
an insert major body including two hexagonal faces, a front hexagonal face and a back hexagonal face, facing away from each other and six side faces arranged around the two hexagonal faces, wherein:
the insert major body is formed to be rotationally symmetrical at 120° intervals about an insert center line passing through centers of the two hexagonal faces;
a first cutting edge at an intersection of the six side faces and the front hexagonal face, and a second cutting edge at an intersection of the six side faces and the back hexagonal face, the first cutting edge including exactly three major cutting edges and exactly three minor cutting edges with the major cutting edges alternating with the minor cutting edges in a circumferential direction, and the second cutting edge including exactly three major cutting edges and exactly three minor cutting edges with the major cutting edges alternating with the minor cutting edges in the circumferential direction;
a first three side faces of the six side faces each having
one of the major cutting edges of the first cutting edge, and
one of the minor cutting edges of the second cutting edge;

a second three side faces of the six side faces each having
one of the major cutting edges of the second cutting edge, and
one of the minor cutting edges of the first cutting edge;

wherein the first three side faces alternate with the second three side faces in the circumferential direction;
each side face having a major flank face connected to the major cutting edge and a minor flank face connected to the minor cutting edge;
in each of the six side faces the major flank face intersects the minor flank face to form a concave single curved surface in a cross-section view along the insert center line;
in each of the six side faces, a sum of a major flank face angle α formed by the major flank face with respect to a plane which is perpendicular to the insert center line intersecting the major cutting edge and a minor flank face angle β formed by the minor flank face with respect to a plane which is perpendicular to the insert center line intersecting the minor cutting edge is smaller than 180°, the major flank face angle α is an obtuse angle;
in a view parallel to the insert center line of the front hexagonal face from a direction facing the front hexagonal face, in each of the six side faces, the minor cutting edge protrudes in a direction perpendicular to the insert center line of the insert major body more than the major cutting edge,
in each of the six side faces, a width of the major flank face is larger than a width of the minor flank face in a direction parallel to the insert center line,
each of the two hexagonal faces including a central portion formed of a flat surface perpendicular to the insert center line, a major rake face at each of the three major cutting edges and a minor rake face at each of the three minor cutting edges,
each minor rake face having
a first minor rake face intersecting the minor cutting edge, and
a second minor rake face intersecting the first minor rake face and spaced apart from the minor cutting edge,
wherein the first minor rake face has a negative rake angle and the second minor rake face has a positive rake angle;

wherein, the plane intersecting the major cutting edges of each hexagonal face protrudes further from an insert mid-plane perpendicular to the insert center line than the plane intersecting the minor cutting edges of the respective hexagonal face.

2. The cutting insert according to claim 1 , further comprising
each major rake face having
a first major rake face intersecting the major cutting edge, and
a second major rake face intersecting the first major rake face and spaced apart from the major cutting edge,

wherein the first major rake face has a rake angle, the second major rake face has a rake angle, the rake angles being different from each other.

3. The cutting insert according to claim 2 , wherein the first major rake angle is 0° and the second major rake angle is positive.

4. An indexable cutting tool comprising:
an insert mounting seat formed at an outer periphery of a distal end portion of a tool major body which, in use, is rotated around an axial line of the tool major body,
wherein the cutting insert according to claim 1 is detachably attached to the insert mounting seat.

Assignees

• Mitsubishi Materials Corp

Inventors

• Hagiwara Takayuki
• Ishimori Shigeru
• Yamazaki Kiichi
• Kitajima Jun

Classifications

• B23C5/202 Primary

  Plate-like cutting inserts with special form (special form related to securing of the insert B23C5/22) · CPC title

• B23C2200/28

  Angles · CPC title

• B23C5/06 Primary

  Face-milling cutters, i.e. having only or primarily a substantially flat cutting surface · CPC title

• B23C2200/365

  Lands, i.e. the outer peripheral section of rake faces · CPC title

• B23C2200/125

  discontinuous · CPC title