Cutting insert, indexable rotary cutting tool, and body of the same

Patent metadata

Field	Value
Publication number	US-12059735-B2
Application number	US-202217842263-A
Country	US
Kind code	B2
Filing date	Jun 16, 2022
Priority date	Jul 15, 2021
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

Provided is a structure for improving accuracy in attaching a cutting tool to a body and making it possible to increase the number of blades while the cutting tool is mounted on the body. A cutting insert 1 includes: an upper surface 10 that has a shape with a lengthwise direction LD and a widthwise direction SD; a lower surface that is located opposite to the upper surface 10; a peripheral side surface 30 that is formed so as to connect the upper surface 10 and the lower surface; cutting edges 51 and 52 that are respectively formed on an intersecting ridge line of the upper surface 10 and the peripheral side surface 30, and on an intersecting ridge line of the lower surface and the peripheral side surface 30, and each have a curved ridge line that extends in a lengthwise direction thereof; and a through hole 60 that penetrates from the upper surface 10 to the lower surface. End surfaces 31 and 32 located in the lengthwise direction LD of the upper surface 10 and the lower surface, of the peripheral side surface 30, are respectively inclined with respect to the upper surface 10 and the lower surface, and are parallel to each other. A reference surface 33 that is located opposite to the cutting edges 51 and 52, of the peripheral side surface 30, is a flat surface that is orthogonal to the upper surface 10 and the lower surface.

First claim

What is claimed is:

1. A cutting insert comprising:
an upper surface that has a shape with a lengthwise direction and a widthwise direction;
a lower surface that is located opposite to the upper surface and has a shape with a lengthwise direction and a widthwise direction;
a peripheral side surface that is formed so as to connect the upper surface and the lower surface;
cutting edges that are respectively formed on an intersecting ridge line of the upper surface and the peripheral side surface, and on an intersecting ridge line of the lower surface and the peripheral side surface, and each have a curved ridge line that extends in a lengthwise direction thereof; and
a through hole that penetrates from the upper surface to the lower surface,
wherein end surfaces located in the lengthwise direction of the upper surface and the lower surface, of the peripheral surface, are respectively inclined with respect to the upper surface and the lower surface, and are parallel to each other,
a reference surface that is located opposite to the cutting edges, of the peripheral surface, is a flat surface that is orthogonal to the upper surface and the lower surface, flanks of the cutting edges have a shape in which a clearance angle thereof gradually changes from a positive angle to a negative angle in the lengthwise direction, and
the upper surface is formed so as to have a shape in which a height of the upper surface in an axial direction that is orthogonal to the lengthwise direction and the widthwise direction decreases in a direction toward the cutting edge, and thereafter gradually increases in the direction toward the cutting edge.

2. The cutting insert according to claim 1 ,
wherein the curved cutting edges, and intersection regions that are respectively located in the lengthwise direction of the upper surface and the lower surface, are connected to each other via curved portions when viewed in a direction that is orthogonal to the upper surface and a direction orthogonal to the lower surface, respectively.

3. The cutting insert according to claim 2 ,
wherein each of the curved portions has an arc shape.

4. The cutting insert according to claim 3 ,
wherein a radius of curvature of the curved portions is smaller than a radius of curvature of the cutting edges.

5. The cutting insert according to claim 1 ,
wherein the upper surface and the lower surface have an axially symmetric shape centered around a central axis of symmetry that is orthogonal to the reference surface, and are offset from each other in the lengthwise direction at the same angle as an inclination angle of the end surfaces.

6. The cutting insert according to claim 1 ,
wherein a height of the cutting edge in the axial direction is larger than a height of a flat portion around the through hole, of the upper surface.

7. A body of a cutting tool to which the cutting insert according to claim 1 can be detachably attached, the body comprising:
a seating surface on which a flat portion around the through hole of the upper surface or the lower surface of the cutting insert is to be seated as an attachment surface; and
a binding surface that is orthogonal to the seating surface and is to abut against the reference surface of the cutting insert.

8. A rotary cutting tool comprising the body according to claim 7 .

Assignees

• Tungaloy Corp

Inventors

• Hori Issei
• Saji Ryuichi

Classifications

• B23C2210/084

  Curved cutting edges · CPC title

• B23C5/02 Primary

  characterised by the shape of the cutter · CPC title

• B23C2200/293

  Variable clearance angles · CPC title

• B23C2200/203

  Curved cutting edges · CPC title

• B23C2200/284

  Negative clearance angles · CPC title