High-feed milling tool

Patent metadata

Field	Value
Publication number	US-11731204-B2
Application number	US-202117481355-A
Country	US
Kind code	B2
Filing date	Sep 22, 2021
Priority date	Oct 19, 2020
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A milling tool having a radial cutting edge for milling high-feed rates. The radial cutting edge having first, second and third sub-edges which extend at angles which are relatively small when formed with a longitudinal axis AL of the milling tool, thereby allowing the high-feed rates.

First claim

What is claimed is:

1. A milling tool having a tool rotation direction and a tool counter-rotation direction opposite thereto, the milling tool comprising:
an elongated shank portion and a cutting portion connected to the shank portion;
the shank portion defining:
a longitudinal axis (AL) which defines a downward direction (DD) from the shank portion to the cutting portion and an upward direction (DU) opposite to the downward direction; and
an outward radial direction (DO) perpendicular to the longitudinal axis and outward from the milling tool, and an inward radial direction (DI) opposite to the outward radial direction; and

the cutting portion comprising:
a rake surface;
a relief surface; and
a cutting edge formed along an intersection of the rake surface and the relief surface, the cutting edge comprising a radial cutting edge having an axial edge length LAE measurable parallel to the longitudinal axis (AL) and a radial edge length LRE measureable perpendicular to the longitudinal axis (AL);
wherein, in a top view facing the rake surface, the radial cutting edge comprises:
a first sub-edge having a first longitudinal length L 1 and a first radial length R 1 , a first uppermost point and a first lowermost point which define a first imaginary line (IL 1 ), and a first sub-edge angle k 1 formed between the first imaginary line (IL 1 ) and the longitudinal axis (AL);
a second sub-edge located downwardly of the first sub-edge and having a second longitudinal length L 2 and a second radial length R 2 , a second uppermost point and a second lowermost point which define a second imaginary line (IL 2 ), and a second sub-edge angle k 2 formed between the second imaginary line (IL 2 ) and the longitudinal axis (AL); and
a third sub-edge connecting the first and second sub-edges and having a third longitudinal length L 3 and a third radial length R 3 ;

wherein:
the first sub-edge extends towards the third sub-edge in the downward (DD) and outward (DO) radial directions;
the second sub-edge extends towards the third sub-edge in the upward (DU) and outward (DO) radial directions; and
in said top view facing the rake surface, the first sub-edge angle k 1 fulfills the condition 12°<k 1 <25° and/or the second sub-edge angle k 2 fulfills the condition 12°<k 2 <25°.

2. The milling tool according to claim 1 , wherein: the first sub-edge angle k 1 fulfills the condition: 15°<k 1 <22° and/or the second sub-edge angle k 2 fulfills the condition: 15°<k 2 <22°.

3. The milling tool according to claim 1 , wherein:
the milling tool is an insert-mill holder;
the cutting portion comprises at least one insert pocket having an insert seat surface and first, second and third support walls; and
said rake surface, said relief surface and said cutting edge all belong to a cutting insert mounted in the at least one insert pocket, the cutting insert further comprising:
a bottom surface opposite the rake surface; and
an insert axis passing through the center of the rake surface and bottom surface, the insert axis defining an upward insert direction and a downward insert direction opposite to the upward insert direction; wherein:
the relief surface connects the rake surface to the bottom surface, and comprises a support portion having first, second and third insert abutment surfaces.

4. The milling tool according to claim 3 , wherein the cutting insert is mounted to the insert pocket with:
the insert's bottom surface abutting the insert seat surface;
the first insert abutment surface abutting the first support wall;
the second insert abutment surface abutting the second support wall; and
the third insert abutment surface abutting the third support wall.

5. The milling tool according to claim 3 , wherein:
the cutting insert's bottom surface is formed with at least one safety recess;
the insert pocket's insert seat surface comprises a safety projection; and
the at least one safety recess accommodates the safety projection, with a gap remaining all around the safety projection.

6. The milling tool according to claim 3 , wherein a majority of an uppermost corner, to which the radial cutting edge is connected, projects further in the outward direction than the radial peripheral surface along the cutting portion of the insert-mill holder.

7. The milling tool according to claim 3 , wherein a majority of a lowermost corner, to which the radial cutting edge is connected, projects further in the outward direction than the radial peripheral surface along the cutting portion of the insert-mill holder.

8. The milling tool according to claim 3 , wherein an uppermost corner and lowermost corner are connected to the radial cutting edge, and the uppermost corner is located precisely in the upward direction above the lowermost corner.

9. The milling tool according to claim 3 , wherein cutting insert is clamped to the insert pocket only via a screw passing through the cutting insert.

10. The milling tool according to claim 3 , wherein:
the insert pocket comprises an insert seat surface and a threaded bore opening out to the insert seat surface, the threaded bore having a bore axis; and
the bore axis forms a first external bore angle a 1 with the insert seat surface in the outward radial direction, the first external bore angle a 1 fulfilling the condition: 72°<a 1 <88°.

11. The milling tool according to claim 10 , wherein, in a view of the insert seat surface:
the bore axis forms a second external bore angle a 2 with an imaginary bore plane (PB) extending through the center of the bore in the outward radial direction, the second external bore angle a 2 fulfilling the condition: 3°<a 2 <15°.

12. The milling tool according to claim 10 , wherein the threaded bore comprises a threaded section and a relief section having a greater diameter than the threaded section, the relief section being closer than the threaded section to the insert seat surface.

13. The milling tool according to claim 3 , wherein:
the first support wall extends in both the inward radial and downward directions;
the second support wall extends in both the outward radial and downward directions; and
the third support wall, located downwardly of the first support wall and upwardly of the second support wall, extends non-parallel relative to the first support wall and the second support wall.

14. The milling tool according to claim 3 , wherein a first external angle β 1 is formed between the first support wall and the third support wall and fulfills the condition: 130°<β 1 <150°.

15. The milling tool according to claim 3 , wherein a second external angle β 2 is formed between the second support wall and the third support wall and fulfills the condition: 80°<β 2 <120°.

16. The milling tool according to claim 1 , further comprising a fourth sub-edge extending from the second sub-edge in the inward radial direction.

17. The milling tool according to claim 16 , wherein the fourth sub-edge extends from the second sub-edge in both the inward radial and upward directions.

18. The milling tool according to claim 1 , wherein, in a view facing the relief surface, at least one of the first sub-edge and the second sub-edge is straight.

19. The milling tool according to claim 1 , wherein the third longitudinal length L 3 is shorter than both the first longitudinal length L 1 and the second longitudinal length L 2 .

20. The milling tool according to claim 3 , wherein the cutting insert has a non-circular shape, and is three-way indexable about the inser

Assignees

• Iscar Ltd

Inventors

• Hecht Gil

Classifications

• B23C5/109 Primary

  with removable cutting inserts · CPC title

• B23C2200/0405

  Hexagonal · CPC title

• B23C2210/04

  Angles · CPC title

• B23C5/1081

  with permanently fixed cutting inserts  (B23C5/1018 and B23C5/1063 take precedence) · CPC title

• B23C2220/56

  Plunge milling · CPC title