Cutting insert, cutting tool, and method of manufacturing machined product using the same

Patent metadata

Field	Value
Publication number	US-9533356-B2
Application number	US-201214113552-A
Country	US
Kind code	B2
Filing date	Apr 27, 2012
Priority date	Apr 28, 2011
Publication date	Jan 3, 2017
Grant date	Jan 3, 2017

Abstract

A cutting insert includes: a polygonal shaped upper surface; a lower surface; a side surface connected to each of the upper and lower surfaces; and an upper cutting edge located at the intersection of the upper surface and the side surface. The upper surface alternately includes three major corners and three minor corners. The upper cutting edge includes: a corner cutting edge; a minor cutting edge inclined toward the lower surface as separating from the corner cutting edge at a first inclination angle; and a major cutting edge inclined toward the lower surface as separating from the minor cutting edge at a second inclination angle. The corner cutting edge, the minor cutting edge and the major cutting edge are located sequentially from a first major corner to each of first and second minor corners, both of which are adjacent to the first major corner.

First claim

The invention claimed is:

1. A cutting insert, comprising:
a polygonal shaped first surface;
a second surface;
a side surface connected to each of the first surface and the second surface; and
an edge located at an intersection of the first surface and the side surface, wherein
the first surface alternately comprises three major corners, each having a first interior angle, and three minor corners, each having a second interior angle larger than the first interior angle,
the edge comprises
a corner edge,
a minor edge inclined toward the second surface as separating from the corner edge at a first inclination angle (θ 1 ) on a basis of a vertical plane perpendicular to a central axis extending between the first and second surfaces, and
a major edge inclined toward the second surface as separating from the minor edge at a second inclination angle (θ 2 ) larger than the first inclination angle on the basis of the vertical plane, and
the corner edge, the minor edge and the major edge are located sequentially from a first major corner of the three major corners to each of a first minor corner and a second minor corner of the three minor corners, the first and second minor corners being adjacent to the first major corner, wherein the first inclination angle (θ 1 ) is from 3° to 15°, and the second inclination angle (θ 2 ) is from 7° to 19°.

2. The cutting insert according to claim 1 , wherein the corner edge is parallel to the vertical plane.

3. The cutting insert according to claim 1 , wherein the major edge has a concave shape recessed toward the second surface in a side view.

4. The cutting insert according to claim 1 , wherein the minor edge has a straight line shape.

5. The cutting insert according to claim 1 , wherein the first interior angle is a substantially right angle.

6. The cutting insert according to claim 1 , wherein
the first surface further comprises a rake surface being continuous with the edge and inclined toward the second surface as going inward from the edge at a third inclination angle on the basis of the vertical plane, and
the rake surface comprises a minor rake surface located inward of the minor edge, and a major rake surface located inward of the major edge.

7. The cutting insert according to claim 6 , wherein an angle formed by the minor rake surface and the major rake surface is substantially identical to an angle formed by the minor edge and the major edge.

8. The cutting insert according to claim 7 , wherein a boundary of the minor rake surface and the major rake surface, each being located between the first major corner and the first minor corner, has a substantially constant distance from a straight line connecting the first major corner and the second minor corner in a top view.

9. The cutting insert according to claim 7 , wherein a boundary of the minor rake surface and the major rake surface extends from a edge boundary of the minor edge and the major edge in a direction substantially perpendicular to a tangential line at the edge boundary in the top view.

10. The cutting insert according to claim 6 , wherein the third inclination angle of the rake surface is substantially constant on the minor rake surface, a boundary of the minor rake surface and the major rake surface, and the major rake surface.

11. The cutting insert according to claim 6 , wherein a width of the rake surface is decreased as going from the first major corner to the first minor corner.

12. The cutting insert according to claim 6 , wherein the first surface further comprises a protruded surface being continuous with the rake surface and inclined as going inward from the edge at a fourth inclination angle in a direction to separate from the second surface on the basis of the vertical plane.

13. The cutting insert according to claim 12 , wherein the first surface further comprises a flat-surface-shaped mount part, and the rake surface is continuous with the mount part at portions of the rake surface respectively corresponding to the three major corners, and is continuous with the mount part at portions of the rake surface respectively corresponding to the three minor corners with the protruded surface interposed therebetween.

14. A cutting tool, comprising:
a cutting insert according to claim 1 ; and
a holder configured to attach the cutting insert thereto, wherein
a first major cutting section of the edge in the cutting insert extending from the first major corner to the first minor corner adjacent thereto has a positive axial rake angle, and a non-cutting section of the edge extending from the first minor corner to the second major corner adjacent thereto has a negative axial rake angle.

15. A method of manufacturing a machined product, comprising:
rotating a cutting tool according to claim 14 on a basis of a rotation axis of the holder;
bringing the edge of the cutting tool being rotated into contact with a surface of a workpiece; and
separating the cutting tool from the workpiece.

Assignees

• Koga Kenichirou
• Shibata Masahiro
• Yamamichi Kazuki
• Kyocera Corp

Inventors

• Koga Kenichirou
• Shibata Masahiro
• Yamamichi Kazuki

Classifications

• B23C5/06

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

• B23C5/202 Primary

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

• B23C2200/208

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

• B23C2200/085

  discontinuous · CPC title

• B23C2210/0457

  radial rake angle · CPC title