Cutting insert, cutting tool, and method of manufacturing machined product

Patent metadata

Field	Value
Publication number	US-10213839-B2
Application number	US-201515511796-A
Country	US
Kind code	B2
Filing date	Aug 31, 2015
Priority date	Sep 18, 2014
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A cutting insert of an embodiment includes a cutting edge located at an intersecting part of an upper surface and a side surface. The cutting edge includes a corner cutting edge, a major cutting edge, and a flat cutting edge. The upper surface includes a first land surface located along the corner cutting edge, a second land surface located along the major cutting edge, and a third land surface located along the flat cutting edge. A maximum value of a width of the third land surface is smaller than a maximum value of a width of each of the first land surface and the second land surface in a top view.

First claim

The invention claimed is:

1. A cutting insert, comprising:
an upper surface comprising a corner part and a side part adjacent to the corner part;
a lower surface located on a side opposite to the upper surface;
a side surface located between the upper surface and the lower surface; and
a cutting edge located along an intersection part of the upper surface and the side surface,
wherein the cutting edge comprises a corner cutting edge located at the corner part, a major cutting edge located at the side part, and a flat cutting edge located between the corner cutting edge and the major cutting edge,
wherein the upper surface comprises
a land surface located along the cutting edge, and
a rake surface located more inward than the land surface and having an inclination angle larger than the land surface,

wherein a width of the land surface is a length between the cutting edge and the rake surface in a top view,
wherein the land surface comprises a first land surface located along the corner cutting edge, a second land surface located along the major cutting edge, and a third land surface located along the flat cutting edge, and
wherein a maximum value of the width of the third land surface is smaller than a maximum value of the width of each of the first land surface and the second land surface.

2. The cutting insert according to claim 1 , wherein the first land surface has a smaller width as approaching the third land surface in a top view.

3. The cutting insert according to claim 2 , wherein a width of the second land surface is constant in a top view.

4. The cutting insert according to claim 1 , wherein the first land surface and the second land surface have a flat surface-shaped portion, and the third land surface has a protruding curved surface shape.

5. The cutting insert according to claim 1 , wherein the maximum value of the width of the second land surface is larger than the maximum value of the width of the first land surface in a top view.

6. The cutting insert according to claim 1 ,
wherein the rake surface comprises a first rake surface located inside the first land surface, a second rake surface located inside the second land surface, and a third rake surface located inside the third land surface, and
wherein a maximum value of a rake angle of the first rake surface is larger than a maximum value of a rake angle of each of the second rake surface and the third rake surface.

7. The cutting insert according to claim 6 , wherein the maximum value of the rake angle of the second rake surface is equal to the maximum value of the rake angle of the third rake surface.

8. The cutting insert according to claim 6 , wherein the third rake surface is more concave downward than the first rake surface and the second rake surface.

9. The cutting insert according to claim 6 ,
wherein the first rake surface comprises a circular arc-shaped first outer rake surface and a straight line-shaped first inner rake surface located more away from the corner cutting edge than the first outer rake surface in a cross-section orthogonal to the corner cutting edge,
wherein the second rake surface comprises a circular arc-shaped second outer rake surface and a straight line-shaped second inner rake surface located more away from the major cutting edge than the second outer rake surface in a cross-section orthogonal to the major cutting edge,
wherein the third rake surface comprises a circular arc-shaped third outer rake surface and a straight line-shaped third inner rake surface located more away from the flat cutting edge than the third outer rake surface in a cross-section orthogonal to the flat cutting edge, and
wherein a radius of curvature of the first outer rake surface is smaller than a radius of curvature of each of the second outer rake surface and the third outer rake surface.

10. The cutting insert according to claim 9 , wherein a rake angle of the first inner rake surface is larger than a rake angle of each of the second inner rake surface and the third inner rake surface.

11. The cutting insert according to claim 9 , wherein a width of the first inner rake surface in the cross-section orthogonal to the corner cutting edge is smaller than a width of the second inner rake surface in the cross-section orthogonal to the major cutting edge, and larger than a width of the third inner rake surface in the cross-section orthogonal to the flat cutting edge.

12. A cutting tool, comprising:
a holder comprising an insert pocket on a front end side of the holder; and
a cutting insert according to claim 1 , the cutting insert being attached to the insert pocket so that at least a part of the cutting edge projects beyond the front end of the holder.

13. A method of manufacturing a machined product, comprising:
rotating a workpiece;
bringing the cutting edge of the cutting tool according to claim 12 into contact with the workpiece being rotated; and
moving the cutting tool away from the workpiece.

Assignees

• Kyocera Corp

Inventors

• Sakai Kouhei

Classifications

• B23B2200/245

  rounded · CPC title

• B23B2200/208

  with wiper, i.e. an auxiliary cutting edge to improve surface finish · CPC title

• B23B2200/0447

  Parallelogram · CPC title

• B23B27/141 Primary

  Specially shaped plate-like cutting inserts, i.e. length greater or equal to width, width greater than or equal to thickness (with specially shaped plate-like exchangeable cutting inserts, e.g. chip-breaking groove, B23B27/1603; with removable plate-like milling cutting inserts of special shape B23C5/202) · CPC title

• B23B2222/16

  Cermet · CPC title