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

Patent metadata

Field	Value
Publication number	US-10160047-B2
Application number	US-201414900058-A
Country	US
Kind code	B2
Filing date	Jun 24, 2014
Priority date	Jun 27, 2013
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

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 an edge and a pair of corner parts adjacent to the edge;
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;
a pair of corner cutting edges located at the pair of corner parts; and
a main cutting edge located in the edge, wherein
the main cutting edge is upwardly convex in shape and comprises an upwardly convex curving portion and a pair of linear portions respectively extending toward the pair of corner cutting edges from the curving portion in a side view,
a height of the lowest point of the main cutting edge is equal to a height of the highest point of the corner cutting edge or a height of every point of the main cutting edge is higher than a height of the highest point of the corner cutting edge, and
a 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 contiguous to a machined surface of a work material during cutting of the work material.

2. The cutting insert according to claim 1 , wherein
the lateral surface comprises a flat part continuous with the main cutting edge.

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

4. The cutting insert according to claim 1 , wherein
the pair of linear portions are formed of a first linear portion extending from the curving portion toward one of the corner cutting edges contiguous to the machined surface of the work material and a second linear portion extending from the curving portion toward the other corner cutting edge separated from the machined surface of the work material, and
the second linear portion is longer than the first linear portion.

5. The cutting insert according to claim 4 , 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.

6. The cutting insert according to claim 1 , wherein
the main cutting edge further comprises a downwardly concave bent part when viewed from the side located between the linear portion extending toward the other corner cutting edge located to be separated from the machined surface of the work material upon cutting the work material and the other corner cutting edge.

7. The cutting insert according to claim 6 , wherein
in the main cutting edge, the bent part is recessed toward the center of the upper surface when viewed from above.

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

9. A method for manufacturing a cut workpiece, the method comprising the steps of:
rotating the cutting tool described in claim 8 ;
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.

Assignees

• Kyocera Corp

Inventors

• Yamamichi Kazuki

Classifications

• B23C2200/203

  Curved cutting edges · CPC title

• B23C2200/366

  Variable · CPC title

• B23C5/06

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

• B23C2200/201

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

• B23C2200/0455

  Square · CPC title