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

• US 9,393,626 B2
• Filed: 03/27/2013
• Issued: 07/19/2016
• Est. Priority Date: 03/30/2012
• Status: Active Grant

• Current Assignee: Kyocera Corporation
• Original Assignee: Kyocera Corporation
• Inventors: Onodera, Chie
• Primary Examiner(s): FRIDIE JR, WILLMON
• Application Number:
  US14/388,970
• Publication Number:
  US 20150090081A1
• Time in Patent Office: 1,210 Days
• US Class Current: 1/1
• CPC Class Codes: B23B 2200/0447 Parallelogram
• CPC Class Codes: B23B 2200/081 with projections chip breaking projections in general B23B2200/321
• CPC Class Codes: B23B 2200/201 Details of the nose radius and immediately surrounding area
• CPC Class Codes: B23B 27/143 characterised by having chip-breakers
• CPC Class Codes: Y10T 407/22 including holder having seat for inserted tool
• CPC Class Codes: Y10T 407/245 comprising concave surface in cutting face of tool
• CPC Class Codes: Y10T 82/10 Process of turning

Abstract

A cutting insert has a polygonal columnar shape and includes an upper surface, a lower surface, a side surface located between the upper surface and the lower surface, and a cutting edge formed at an intersection of the upper surface and the side surface. The upper surface includes a convex-shaped main part including a flat upper end surface, a first projection projecting from the main part to a corner part of the upper surface, a second projection projecting from the first projection toward the corner part, and a pair of third projections respectively projecting from the first projection toward a periphery of the upper surface that interpose at least a part of the second projection between the pair of third projections. A surface of the first projection is an inclined surface curved in a concave shape, and a surface of the second projection is a planar inclined surface.

Claims

1. A cutting insert, comprising:

an upper surface, a lower surface and a side surface located between the upper surface and the lower surface, and a polygonal plate-shaped in which a cutting edge is formed at an intersection of the upper surface and the side surface,

wherein the upper surface comprises a convex-shaped main part comprising a flat upper end surface, a first projection projecting from the main part to a corner part of the upper surface in a top plan view, a second projection projecting from the first projection toward the corner part in the top plan view, and a pair of third projections respectively projecting from the first projection toward a periphery of the upper surface so as to interpose at least a part of the second projection between the pair of third projections in the top plan view,

wherein a surface of the first projection is an inclined surface curved in a concave shape, and a surface of the second projection is a planar inclined surface in a portion located on a bisector of the corner part in the top plan view,

wherein a width of the inclined surface curved in the concave shape of the first projection in a direction orthogonal to a direction in which the first projection projects is gradually decreased from a rear end of the inclined surface to a front end thereof in the top plan view, and

wherein a width of the planar inclined surface of the second projection in a direction orthogonal to a direction in which the second projection projects is gradually increased from a rear end of the inclined surface to a front end thereof in the top plan view.

2. A cutting insert, comprising:

an upper surface, a lower surface and a side surface located between the upper surface and the lower surface, and a polygonal plate-shaped in which a cutting edge is formed at an intersection of the upper surface and the side surface,

wherein the upper surface comprises a convex-shaped main part comprising a flat upper end surface, a first projection projecting from the main part to a corner part of the upper surface in a top plan view, a second projection projecting from the first projection toward the corner part in the top plan view, and a pair of third projections respectively projecting from the first projection toward a periphery of the upper surface so as to interpose at least a part of the second projection between the pair of third projections in the top plan view,

wherein a surface of the first projection is an inclined surface curved in a concave shape, and a surface of the second projection is a planar inclined surface in a portion located on a bisector of the corner part in the top plan view, and

wherein each of the pair of third projections is configured to have a surface curved in a convex shape on a region adjacent to an upper end of the third projection and a surface curved in a concave shape on a region adjacent to a lower end thereof.

3. The cutting insert according to claim 2, wherein a height of an upper end of each of the pair of the third projections is identical with a height of an upper end of the second projection.

4. The cutting insert according to claim 2, wherein an upper end of each of the pair of third projections is spaced apart from the first projection.

5. The cutting insert according to claim 2, wherein the second projection is located further away from the corner part than a straight line connecting front ends of the pair of third projections.

6. The cutting insert according to claim 2, wherein a direction in which one of the pair of third projections projects is approximately parallel to a portion of the cutting edge which is located in a direction in which another of the pair of third projections projects in the top plan view.

7. A cutting tool, comprising:

a cutting insert according to claim 2; and

a holder configured to attach the cutting insert thereto.

8. A method of manufacturing a machined product, comprising:

rotating a workpiece;

bringing the cutting edge of the cutting tool according to claim 7 into contact with the workpiece being rotated; and

separating the cutting tool from the workpiece.