Cutting insert, cutting tool, and method for manufacturing a cut workpiece

Patent metadata

Field	Value
Publication number	US-10576555-B2
Application number	US-201816196930-A
Country	US
Kind code	B2
Filing date	Nov 20, 2018
Priority date	Jun 27, 2013
Publication date	Mar 3, 2020
Grant date	Mar 3, 2020

Abstract

This cutting insert is provided with a lower surface of polygonal shape including side parts and a pair of corner parts, an upper surface, a lateral surface situated between the lower surface and the upper surface, a pair of corner cutting edges located at the pair of corners, and a main cutting edge located in a side portion. The main cutting edge is upwardly convex in shape, and in side view includes an upwardly convex curving portion, and a pair of linear portions respectively extending toward the pair of corner cutting edges from the curving portion. The top portion of the curving portion is positioned more toward the one of the corner cutting edges which, of the pair of corner cutting edges, is that contiguous to a working surface of a work material during cutting of the work material.

First claim

The invention claimed is:

1. A cutting insert comprising:
an upper surface with a polygonal shape comprising:
a first corner which is contiguous to a machined surface of a work material during cutting of the work material;
a second corner; and
an edge located between the first corner and the second corner;

a lower surface with a polygonal shape located opposite to the upper surface;
a lateral surface provided between the lower surface and the upper surface, and comprising:
a first curved part having a curved shape;
a second curved part having a curved shape; and
a flat part having a flat shape;

a first corner cutting edge located at the first corner and connected to the first curved part;
a second corner cutting edge located at the second corner and connected to the second curved part; and
a main cutting edge located in the edge and connected to the flat part, wherein
the main cutting edge is upwardly convex in shape and comprises:
an upwardly convex curving portion;
a first linear portion extending from the curving portion toward the first corner cutting edge; and
a second linear portion extending from the curving portion toward the second corner cutting edge, and

a top portion of the curving portion is closer to the first corner than the second corner.

2. The cutting insert according to claim 1 , wherein
the curving portion has an arc shape in a side view.

3. The cutting insert according to claim 1 , wherein
the second linear portion is longer than the first linear portion.

4. The cutting insert according to claim 3 , wherein
an inclination angle of the first linear portion with respect to a virtual plane perpendicular to a center axis connecting a center of the upper surface and a center of the lower surface is greater than an inclination angle of the second linear portion with respect to the virtual plane in a side view.

5. The cutting insert according to claim 1 , wherein
the main cutting edge further comprises a downwardly concave bent part in a side view located between the second linear portion and the second corner cutting edge.

6. The cutting insert according to claim 5 , wherein
in the main cutting edge, the bent part is recessed toward the center of the upper surface in a top view.

7. A cutting tool comprising:
a holder comprising a plurality of insert pockets on a leading end side; and
the cutting insert described claim 1 , which is mounted in the insert pockets such that the main cutting edge protrudes from the holder.

8. A method for manufacturing a cut workpiece, the method comprising the steps of:
rotating the cutting tool described in claim 7 ;
bringing the main cutting edge in the rotating cutting tool into contact with a work material; and
separating the cutting tool from the work material.

9. The cutting insert according to claim 1 , wherein
the first corner cutting edge has a downwardly concave curved shape in a side view.

Assignees

• Kyocera Corp

Inventors

• Yamamichi Kazuki

Classifications

• B23C2200/201

  Details of the nose radius and immediately surrounding areas · CPC title

• B23C2200/0455

  Square · CPC title

• B23C2200/203

  Curved cutting edges · CPC title

• B23C5/06

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

• B23C2200/366

  Variable · CPC title