Cutting insert and indexable insert-type cutting tool

Patent metadata

Field	Value
Publication number	US-9649701-B2
Application number	US-201214348198-A
Country	US
Kind code	B2
Filing date	Sep 27, 2012
Priority date	Oct 4, 2011
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

A cutting insert and an indexable insert-type cutting tool includes a cutting edge ( 6 A) 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 ( 6 A) 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 ( 6 A) 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.

First claim

What is claimed is:

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, in a top view of the cutting insert.

2. The cutting insert according to claim 1 , wherein
each of the polygonal faces of the insert main body is formed in a rectangular shape;
the insert main body is provided with a pair of long side faces arranged so as to face each other and a pair of short side faces arranged so as to face each other;
a major cutting edge is formed at each of the pair of side ridge portions of the pair of long side faces, each of the pair of side ridge portions being a portion intersecting the pair of long side faces and the pair of polygonal faces; and
each flank face adjacent to the major cutting edges is formed in the shape of a twisted face and the pair of side ridge portions on which the major cutting edge is formed intersect each other in the top view of the cutting insert.

3. The cutting insert according to claim 2 , wherein
the major cutting edge gradually slopes downward toward the second corner portion of the polygonal face from the first corner portion thereof with respect to a direction of an insert central line passing through the centers of the pair of polygonal faces, and inclines toward the other polygonal face on the opposite side of the polygonal face on which the major cutting edge is formed, when the long side face is viewed.

4. The cutting insert according to claim 2 , wherein
the polygonal face of the insert main body is formed in the shape of a parallelogram which has a pair of obtuse angle corner portions and a pair of acute angle corner portions;
a corner edge continuing to the major cutting edge is formed at each of the acute angle corner portions on each of the polygonal faces;
a minor cutting edge continuing to the corner edge is formed at each of the acute angle corner portions of a side ridge portion of each of the polygonal faces, the side ridge portion being a portion intersecting each of the polygonal faces and each of the short side faces;
the flank face is formed in the shape of a twisted face in which a flank angle with respect to the major cutting edge gradually increases in a positive angle side while the flank face becoming close to the obtuse angle corner portion from the acute angle corner portion; and
the pair of side ridge portions on which the major cutting edge is formed intersect each other in such a manner that the obtuse angle corner portion of one side ridge portion protrudes outside the other side ridge portion in the top view of the cutting insert.

5. The cutting insert according to claim 4 , wherein
the major cutting edge gradually slopes downward toward the obtuse angle corner portion of the polygonal face formed in the shape of a parallelogram from the acute angle corner portion thereof with respect to a direction of the insert central line passing through the centers of the pair of polygonal faces, and inclines so as to move toward the other polygonal face on the opposite side of the polygonal face on which the major cutting edge is formed, when the long side face is viewed.

6. The cutting insert according to claim 4 , wherein
the minor cutting edge gradually slopes downward from the corner edge toward a location separating from the corner edge with respect to the direction of the insert central line passing through the centers of the pair of polygonal faces, and inclines toward the other polygonal face on the opposite side of the polygonal face on which the minor cutting edge is formed, when the short side face is viewed.

7. The cutting insert according to claim 4 , wherein
of the side ridge portion of each of the polygonal faces, the side ridge portion being a portion intersecting each of the polygonal faces and each of the short side faces, a part continuing to the opposite side of the corner edge of the minor cutting edge is used as a ramping edge, and
of the short side face, a part continuing to the ramping edge gradually inclines toward inside the insert main body while the part extending away from the ramping edge and becoming close to the other polygonal face on the opposite side of the polygonal face on which the ramping edge is formed.

8. The cutting insert according to claim 1 , wherein
the insert main body is formed in the shape of 180° rotationally symmetrical with respect to the insert central line passing through the centers of the pair of polygonal faces and provided with at least the pair of side faces on which the cutting edge is formed, and
of the pair of side faces, when the cutting edge of one side face is used for cutting, a contact portion which is in contact with a contacted portion formed on a wall face of the insert seat is formed on the other side face.

9. The cutting insert according to claim 1 , wherein
the insert main body is formed in the shape of rotationally symmetrical with respect to the insert central line passing through the centers of the pair of polygonal faces and provided with at least the two side faces on which the cutting edge is formed, and
of the side faces, when the cutting edge of one of the side faces is used for cutting, a contact portion in contact with a contacted portion formed on a wall face of the insert seat is formed on at least one side face of remaining side faces.

10. The cutting insert according to claim 8 or claim 9 , wherein
a convex curved surface portion continuing to a flank face adjacent to the cutting edge and a recessed curved surface portion continuing to the convex curved surface portion are formed on the side face,
the convex curved surface portion is curved in the shape of a convex curved surface which is raised outside the insert main body,
the recessed curved surface portion is curved in the shape of a recessed curved surface which is recessed inside the insert main body,
the contact portion is formed on the convex curved surface portion, and
a curvature radius of the convex curved surface portion is kept constant in a direction at which t

Assignees

• Mitsubishi Materials Corp

Inventors

• Horiike Nobukazu
• Takagi Yuji

Classifications

• B23C5/22

  Securing arrangements for bits or teeth {or cutting inserts} · CPC title

• B23C2210/50

  Cutting inserts · CPC title

• B23C5/202 Primary

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

• B23C5/109 Primary

  with removable cutting inserts · CPC title

• B23C2210/0457

  radial rake angle · CPC title