Cutting insert

Patent metadata

Field	Value
Publication number	US-2024100605-A1
Application number	US-202318452128-A
Country	US
Kind code	A1
Filing date	Aug 18, 2023
Priority date	Sep 26, 2022
Publication date	Mar 28, 2024
Grant date	—

Abstract

To provide a cutting insert that readily fragmentizes chips, and that has excellent durability.
At least a cutting part of a cutting insert is formed of a sintered compact. The sintered compact includes a chip breaker that is a recessed portion in which a partial region of a cutting part upper surface is depressed downward. The chip breaker includes a downward inclined surface, an upward inclined surface, a jutting portion that juts out along a first axial line that passes through a distant end of a cutting edge, and a stepped surface that adjoins the jutting portion in a Y axis direction orthogonal to the first axial line. An upper end of the jutting portion is formed at a height of an upper stage. The stepped surface is formed at a height of an intermediate stage at a part closest to the first axial line.

First claim

What is claimed is:

1 . A cutting insert of which at least a cutting part is formed of a sintered compact, the cutting insert comprising:
an insert upper surface; and an insert lower surface on an opposite side from the insert upper surface, wherein, with a direction from the insert upper surface toward the insert lower surface as downward, and a direction from the insert lower surface toward the insert upper surface as upward, the sintered compact includes
a cutting part upper surface that faces upward,
a cutting edge formed on an outer fringe of the cutting part upper surface, and
a chip breaker in which part of the cutting part upper surface is depressed downward,
with a direction parallel to a first axial line that is a straight line orthogonal to a center-of-gravity axis passing through a center of gravity of the insert upper surface and a center of gravity of the insert lower surface and that passes through a distant end of the cutting edge that is farthest from the center-of-gravity axis as an X axis direction, and a direction intersecting both the X axis direction and an up-down direction as a Y axis direction, the chip breaker includes
a downward inclined surface that descends the further away from the cutting edge in the X axis direction, to a height of a lower stage,
an upward inclined surface that ascends the further away from the cutting edge in the X axis direction, from the height of the lower stage,
a jutting portion that juts out along the first axial line in a direction from the center-of-gravity axis toward the cutting edge, and of which a jutting end faces the downward inclined surface, and
a stepped surface that adjoins the jutting portion from at least one side in the Y axis direction,
an upper end of the jutting portion is formed at a height of an upper stage that is higher than the height of the lower stage, and the stepped surface is a surface that faces upward, and that is formed at a height of an intermediate stage that is, at a part closest to the first axial line, lower than the height of the upper stage, and higher than the height of the lower stage.

2 . The cutting insert according to claim 1 , wherein the stepped surface is inclined ascending from the height of the intermediate stage the further away from the first axial line in the Y axis direction.

3 . The cutting insert according to claim 1 , wherein the jutting end is formed as a conical surface.

4 . The cutting insert according to claim 1 , wherein
the cutting edge includes
a corner cutting edge that is formed in an arc shape, and
a wiper cutting edge that is formed in an arc shape with a radius of curvature that is larger than that of the corner cutting edge, and that continues from one end of the corner cutting edge.

5 . The cutting insert according to claim 1 , wherein the sintered compact is a sintered compact of which a primary component is cubic boron nitride (CBN) or polycrystalline diamond (PCD).

6 . The cutting insert according to claim 2 , wherein the sintered compact is a sintered compact of which a primary component is cubic boron nitride (CBN) or polycrystalline diamond (PCD).

7 . The cutting insert according to claim 3 , wherein the sintered compact is a sintered compact of which a primary component is cubic boron nitride (CBN) or polycrystalline diamond (PCD).

8 . The cutting insert according to claim 4 , wherein the sintered compact is a sintered compact of which a primary component is cubic boron nitride (CBN) or polycrystalline diamond (PCD).

Assignees

• Tungaloy Corp

Inventors

• SASAKI Yasutake

Classifications

• B23B27/14 Primary

  Cutting tools of which the bits or tips {or cutting inserts} are of special material · CPC title

• B23B2200/321

  by chip breaking projections · CPC title

• B23B2226/315

  polycrystalline [PCD] · CPC title

• B23B2265/08

  Conical · CPC title

• B23B27/143 Primary

  characterised by having chip-breakers · CPC title