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

Patent metadata

Field	Value
Publication number	US-9327354-B2
Application number	US-201214354893-A
Country	US
Kind code	B2
Filing date	May 30, 2012
Priority date	Oct 31, 2011
Publication date	May 3, 2016
Grant date	May 3, 2016

Abstract

A cutting insert comprises an upper surface including a first corner, and a second and third corner, respectively, adjacent to both sides of the first corner. The upper surface sequentially includes a rake surface along an upper cutting edge, inclined toward a lower surface, going inward from the upper cutting edge at a rake angle on a basis of a perpendicular plane perpendicular to a central axis extending between the upper and lower surfaces, and a connection surface more inward than the rake surface, inclined toward the lower surface, going inward at a connection angle on the basis of the perpendicular plane. An intersecting part of the rake surface and the connection surface includes a highest position in a portion of the intersecting part corresponding to a minor rake surface. A cutting tool with cutting insert, and a method of producing a machined product using the cutting tool are provided.

First claim

The invention claimed is:

1. A cutting insert, comprising:
a polygonal shaped upper surface;
a lower surface being identical in shape to the upper surface;
a side surface connected to each of the upper surface and the lower surface; and
an upper cutting edge located at an intersecting part of the upper surface and the side surface,
wherein the upper surface comprises a first corner, and a second corner and a third corner respectively adjacent to both sides of the first corner,
wherein the upper surface sequentially comprises
a rake surface located along the upper cutting edge and inclined toward the lower surface as going inward from the upper cutting edge at a rake angle on a basis of a perpendicular plane perpendicular to a central axis extending between the upper surface and the lower surface, and
a connection surface located more inward than the rake surface and inclined toward the lower surface as going inward at a connection angle on the basis of the perpendicular plane,

wherein the upper cutting edge sequentially comprises a corner cutting edge, and a minor cutting edge and a major cutting edge each being inclined toward the lower surface on the basis of the perpendicular plane as going away from the corner cutting edge, and the corner cutting edge and the minor cutting edge and the major cutting edge are disposed in a direction from the first corner to each of the second corner and the third corner,
wherein the rake surface comprises
a minor rake surface located inwardly of the minor cutting edge and inclined toward the lower surface as going inward at a first rake angle on the basis of the perpendicular plane,
a major rake surface located inwardly of the major cutting edge and inclined toward the lower surface as going inward at a second rake angle on the basis of the perpendicular plane, and
a corner rake surface located inwardly of the corner cutting edge and inclined toward the lower surface as going inward at a third rake angle on the basis of the perpendicular plane, and

wherein an intersecting part of the rake surface and the connection surface comprises a highest position in a portion of the intersecting part corresponding to the minor rake surface.

2. The cutting insert according to claim 1 , wherein the intersecting part of the rake surface and the connection surface comprises a region corresponding to the corner rake surface, and a portion of the region passing through a perpendicular bisector of the first corner is located at a lowest position.

3. The cutting insert according to claim 1 , wherein the third rake angle of the corner rake surface is larger than the first rake angle of the minor rake surface.

4. The cutting insert according to claim 1 , wherein the connection angle of the connection surface is larger than the rake angle of the rake surface.

5. The cutting insert according to claim 1 , wherein a width of the connection surface is decreased from the first corner to the second corner in a top view.

6. The cutting insert according to claim 1 , wherein a width of the rake surface is decreased from the first corner to the second corner in a top view.

7. The cutting insert according to claim 1 ,
wherein the upper surface further comprises a planar upper mount part located more inward than the connection surface, and
wherein the upper mount part is located lower than any portion of the upper cutting edge in a side view.

8. The cutting insert according to claim 1 , wherein an inclination angle of the minor cutting edge is smaller than an inclination angle of the major cutting edge.

9. The cutting insert according to claim 1 , wherein the major cutting edge is recessed toward the lower surface in a side view.

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

11. The cutting insert according to claim 1 , further comprises a lower cutting edge located at an intersecting part of the lower surface and the side surface,
wherein the lower surface comprises a planar lower mount part, and one end portion of the lower mount part located close to the central axis is located closer to the upper surface than another end portion of the lower mount part located close to the lower cutting edge on the basis of the perpendicular plane.

12. The cutting insert according to claim 1 ,
wherein the upper surface alternately comprises equal to or more than two major corners, each having a first interior angle, and equal to more than two minor corners, each having a second interior angle larger than the first interior angle, and
wherein the equal to or more than two major corners comprises the first corner, and the equal to or more than two minor corners comprises the second corner.

13. The cutting insert according to claim 11 , wherein the upper cutting edge sequentially comprises the corner cutting edge, the minor cutting edge, and the major cutting edge in a direction from a first major corner of the equal to or more than two major corners to each of a first minor corner and a second minor corner each being adjacent to the first major corner of the equal to or more than two minor corners.

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

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

Assignees

• Yamamichi Kazuki
• Kyocera Corp

Inventors

• Yamamichi Kazuki

Classifications

• B23C2200/205

  Discontinuous cutting edges · CPC title

• B23C2210/045

  axial rake angle · CPC title

• Y10T407/2268

  with chip breaker, guide or deflector · CPC title

• Y10T407/235

  with integral chip breaker, guide or deflector · CPC title

• B23C2210/0457

  radial rake angle · CPC title