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

Patent metadata

Field	Value
Publication number	US-9550239-B2
Application number	US-201314401949-A
Country	US
Kind code	B2
Filing date	May 29, 2013
Priority date	May 30, 2012
Publication date	Jan 24, 2017
Grant date	Jan 24, 2017

Abstract

A cutting insert includes an upper surface, a lower surface, a side surface, and an upper cutting edge. The upper cutting edge includes a major cutting edge having an outwardly projecting curvilinear shape, and a minor cutting edge having a straight line shape and being continuous with the major cutting edge. The side surface includes a continuous inclined surface with the major cutting edge and is inclined outward from the upper surface to the lower surface with respect to a virtual straight line connecting the respective centers of the upper and lower surfaces. An inclination angle of the inclined surface with respect to a virtual straight line on the side surface increases from a portion of the inclined surface which is continuous with an end portion of the major cutting edge to a portion of the inclined surface which is continuous with a center of the major cutting edge.

First claim

The invention claimed is:

1. A cutting insert, comprising:
a lower surface;
an upper surface;
a side surface connected to each of the lower surface and the upper surface; and
an upper cutting edge located along an intersection of the upper surface and the side surface,
wherein the upper cutting edge comprises a first major cutting edge having an outwardly projecting curvilinear shape, and a first minor cutting edge having a straight line shape and being continuous with the first major cutting edge,
wherein the side surface comprises a first inclined surface that is continuous with the first major cutting edge and is inclined further outward as going from the upper surface to the lower surface with respect to a virtual straight line connecting a center of the upper surface and a center of the lower surface, and a first parallel surface that is continuous with the first minor cutting edge and is parallel to the virtual straight line, and
wherein an inclination angle of the first inclined surface with respect to the virtual straight line on the side surface increases as going from a portion of the first inclined surface which is continuous with an end portion of the first major cutting edge to a portion of the first inclined surface which is continuous with a center of the first major cutting edge.

2. The cutting insert according to claim 1 , wherein a width of the first inclined surface on the side surface in a direction parallel to the virtual straight line is constant.

3. The cutting insert according to claim 1 ,
wherein the upper surface comprises a land surface located on an outer circumferential edge of the upper surface so as to be connected to the upper cutting edge, and a rake surface surrounded by the land surface and having a smaller height as going toward the center of the upper surface, and
wherein a lower end of the first inclined surface on the side surface is at a position lower than a lower end of the rake surface.

4. The cutting insert according to claim 3 , wherein in a distance between an outer periphery and an inner periphery of the rake surface increases as going from a portion of the rake surface corresponding to the end portion of the first major cutting edge to a portion of the rake surface corresponding to the center of the first major cutting edge in a top plan view.

5. The cutting insert according to claim 3 ,
wherein the upper surface comprises a breaker surface being surrounded by the rake surface and having a larger height as going toward the center of the upper surface, and
wherein a distance between an outer periphery and an inner periphery of the breaker surface increases as going from a portion of the breaker surface corresponding to the end portion of the first major cutting edge to a portion of the breaker surface corresponding to the center of the first major cutting edge in a top plan view.

6. The cutting insert according to claim 1 , further comprising a lower cutting edge located along an intersection of the lower surface and the side surface,
wherein the lower cutting edge comprises a second major cutting edge having an outwardly projecting curvilinear shape, and a second minor cutting edge having a straight line shape and being continuous with the second major cutting edge,
wherein the side surface comprises a second inclined surface that is continuous with the second major cutting edge and is inclined further outward as going from the lower surface to the upper surface with respect to the virtual straight line, and a second parallel surface that is continuous with the second minor cutting edge and is parallel to the virtual straight line.

7. The cutting insert according to claim 6 , wherein the upper cutting edge and the lower cutting edge are vertically overlapped with each other.

8. The cutting insert according to claim 7 , wherein an inclination angle of the second inclined surface with respect to the virtual straight line is identical with the inclination angle of the first inclined surface with respect to the virtual straight line in a cross section including the virtual straight line and the center of the first major cutting edge.

9. The cutting insert according to claim 7 , wherein a width of the second inclined surface in a direction parallel to the virtual straight line is identical with a width of the first inclined surface in a direction parallel to the virtual straight line in a cross section including the virtual straight line and the center of the first major cutting edge.

10. A cutting tool, comprising:
a holder having a plurality of insert pockets on a front end of the holder; and
a cutting insert according to claim 1 configured to be attached to each of the insert pockets so that the upper cutting edge projects sidewardly of the holder.

11. A method of producing a machined product, comprising:
rotating a cutting tool according to claim 10 ;
bringing the upper cutting edge of the cutting tool being rotated into contact with a workpiece; and
separating the cutting tool from the workpiece.

12. A cutting tool, comprising:
a holder having a plurality of insert pockets on a front end of the holder; and
a cutting insert according to claim 6 configured to be attached to each of the insert pockets so that the upper cutting edge or the lower cutting edge projects sidewardly of the holder.

13. A method of producing a machined product, comprising:
rotating a cutting tool according to claim 12 ;
bringing the upper cutting edge or the lower cutting edge of the cutting tool being rotated into contact with a workpiece; and
separating the cutting tool from the workpiece.

Assignees

• Kyocera Corp

Inventors

• Yamamoto Masahiro

Classifications

• B23C5/202 Primary

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

• B23C5/06 Primary

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

• B23C2200/128

  with one or more grooves · CPC title

• Y10T407/2202

  Plural spaced seats and common holder · CPC title

• B23C2200/203

  Curved cutting edges · CPC title