Cutting insert

Patent metadata

Field	Value
Publication number	US-11192193-B2
Application number	US-202016875916-A
Country	US
Kind code	B2
Filing date	May 15, 2020
Priority date	May 31, 2019
Publication date	Dec 7, 2021
Grant date	Dec 7, 2021

Abstract

An object of this disclosure is to provide a cutting insert that is shaped so that a major cutting edge is not damaged easily. In the cutting insert, a major cutting edge, a corner edge, a flat cutting edge and an inner cutting edge are formed on at least an upper surface, a protruding portion protruding outward is formed in a major cutting edge side surface portion of a side surface that corresponds to the major cutting edge, and a first section is formed in which, when viewed from above, the protrusion amount becomes smaller as the protruding portion separates from the corner edge. Furthermore, the cutting insert includes a first clearance angle changing portion in which a clearance angle becomes smaller as a major cutting edge flank portion formed in a major cutting edge side surface portion separates from the corner edge, and a second clearance angle changing portion in which the clearance angle becomes larger as the major cutting edge flank portion separates from the corner edge, wherein the first clearance angle changing portion is preferably positioned closer to the corner edge than the second clearance angle changing portion is, and, of end portions of the first clearance angle changing portion, the value of the clearance angle at a distal end portion from the corner edge is preferably negative.

First claim

What is claimed is:

1. A cutting insert, comprising a first end surface and a second end surface that have a plurality of side ridges and face each other, and a side surface connecting these two end surfaces, wherein
a cutting edge is formed in at least a part of an intersecting ridge line portion only between the first end surface and the side surface;
the cutting edge has an inner cutting edge, a flat cutting edge connected to the inner cutting edge, a corner edge connected to the flat cutting edge, and a major cutting edge connected to the corner edge;
a major cutting edge side surface portion which is a part of the side surface and corresponds to the major cutting edge; wherein
the major cutting edge side surface portion has:
a protruding portion protruding outward, and
a major cutting edge flank portion adjacent to the major cutting edge;

when viewed in a direction facing the first end surface, the protruding portion has a first section in which a protrusion amount becomes smaller in a direction away from the corner edge;
the major cutting edge flank portion includes a first clearance angle changing portion in which a clearance angle becomes smaller in a direction away from the corner edge, and a second clearance angle changing portion in which a clearance angle becomes larger in the direction away from the corner edge; and
the first clearance angle changing portion is positioned closer to the corner edge than the second clearance angle changing portion.

2. The cutting insert according to claim 1 , wherein a value of a clearance angle of the protruding portion is positive.

3. The cutting insert according to claim 1 , wherein the protruding portion further includes a second section in which the protrusion amount becomes larger in a direction away from the corner edge, and the second section is positioned closer to the corner edge than the first section is.

4. The cutting insert according to claim 1 , wherein, when viewed in the direction facing the first end surface, a starting end of the first section of the protruding portion is positioned closer to the corner edge than an intermediate position of the major cutting edge.

5. A cutting insert to be attached to a body rotating about a rotation axis, comprising:
a first end surface including a rake face;
a second end surface that comes into contact with the body when the cutting insert is attached to the body;
a side surface that includes a minor cutting edge side surface portion connecting the first end surface and the second end surface and facing in a direction of the rotation axis, and a major cutting edge side surface portion connecting the first end surface and the second end surface and facing in an outer radial direction perpendicular to the rotation axis;
a major cutting edge formed in an intersecting ridge line portion only between the first end surface and the major cutting edge side surface portion;
a minor cutting edge formed in an intersecting ridge line portion between the first end surface and the minor cutting edge side surface portion; and
a corner cutting edge connecting the major cutting edge and the minor cutting edge, wherein
a through-hole penetrating the first end surface and the second end surface is formed;
the major cutting edge side surface portion includes a protruding portion that protrudes in a direction perpendicular to the major cutting edge when the first end surface is viewed from a direction parallel to a central axis of the through-hole and includes a second section in which a protrusion amount with respect to the major cutting edge increases in a direction away from the corner cutting edge and a first section that is connected to the second section and in which the protrusion amount decreases in the direction away from the corner cutting edge;
the protruding portion has a first clearance angle changing portion in which a value of a clearance angle decreases in a direction away from the corner cutting edge, and a second clearance angle changing portion which is formed at a position farther away from the corner cutting portion than the first clearance angle changing portion and in which a value of a clearance angle increases in the direction away from the corner edge;
a length of the major cutting edge connected to the second clearance angle changing portion is greater than a length of the major cutting edge connected to the first clearance angle changing portion,
the major cutting edge side surface portion further includes a major cutting edge flank portion adjacent to the major cutting edge;
the major cutting edge flank portion includes a first clearance angle changing portion in which a clearance angle becomes smaller in a direction away from the corner edge, and a second clearance angle changing portion in which a clearance angle becomes larger in the direction away from the corner edge; and
the first clearance angle changing portion is positioned closer to the corner edge than the second clearance angle changing portion is.

6. The cutting insert according to claim 5 , wherein a sum of the length of the major cutting edge connected to the first clearance angle changing portion and the length of the major cutting edge connected to the second clearance angle changing portion is greater than 10% of the length of the entire major cutting edge.

Assignees

• Tungaloy Corp

Inventors

• Aso Takahiro

Classifications

• B23C5/109

  with removable 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

• B23C2200/284

  Negative clearance angles · CPC title

• B23C5/02 Primary

  characterised by the shape of the cutter · CPC title

• B23C2200/04

  Overall shape · CPC title