Cemented carbide corner radius end mill with continuously curved rake ridge and helical flute design

Patent metadata

Field	Value
Publication number	US-10131003-B2
Application number	US-201514948712-A
Country	US
Kind code	B2
Filing date	Nov 23, 2015
Priority date	Nov 23, 2015
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

A corner radius end mill includes a tooth adjacent a helically extending flute. The tooth includes axial and radial relief surfaces connected by a corner relief surface, as well as rake surface having a rake ridge. The rake ridge is continuously curved from a bisector line until at least an axial location rearward of the corner relief surface.

First claim

What is claimed is:

1. A cemented carbide corner radius end mill ( 10 ) having a rotation axis ( 12 ) defining forward and rearward directions (D F , D R ), and comprising:
front and rear ends ( 14 , 16 ) and a peripheral surface ( 18 ) extending therebetween;
a cutting portion ( 20 ) extending rearwardly from the front end ( 14 ); and
a shank portion ( 22 ) located rearward of the cutting portion ( 20 );
the cutting portion ( 20 ) having a cutting portion diameter D E at the front end ( 14 ) and an effective cutting length (L E ) and comprising:
integrally formed teeth ( 24 ) extending from the front end ( 14 ) in the rearward direction, along the peripheral surface ( 18 ); and
a helical flute ( 26 ) located between each pair of adjacent teeth ( 24 ) and having a helix angle H fulfilling the condition: 25°≤H≤60°;
an index angle S subtended between each pair of adjacent teeth ( 24 );
each tooth ( 24 ) comprising:
a relief surface ( 28 );
a rake surface ( 30 );
a cutting edge ( 32 ) formed at an intersection of the relief and rake surfaces ( 28 , 30 ); and
a corner ( 34 ) comprising a circular arc profile defining a portion ( 36 ) of a circle (I C ) having a circle center point (C C ), a circle radius R C , axial and radial tangent lines (L A , L R ), and a bisector line (L B );
the relief surface ( 28 ) comprising:
an axial relief surface ( 28 A) at the front end ( 16 );
a radial relief surface ( 28 B) at the peripheral surface ( 18 ); and
a corner relief surface ( 28 C) connecting the axial and radial relief surfaces ( 28 A, 28 B);
the rake surface ( 30 ) comprising:
a rake cutting sub-surface ( 30 A) extending adjacent the cutting edge ( 32 );
a rake recessed sub-surface ( 30 B); and
a rake ridge ( 30 C) formed at an intersection of the rake cutting and rake recessed sub-surfaces ( 30 A, 30 B) wherein
the rake cutting sub-surface ( 30 A) is closer to the cutting edge ( 32 ) than the rake recessed sub-surface ( 30 B);
the cutting edge ( 32 ) comprising:
an axial sub-edge ( 32 A) at the front end ( 14 ) extending to the axial tangent line (L A );
a corner sub-edge ( 32 B) extending from the axial tangent line (L A ) to the radial tangent line (L R ); and
a radial sub-edge ( 32 C) extending rearward from the radial tangent line (L R );
between the rake ridge ( 30 C) and the cutting edge ( 32 ):
a radial cutting sub-surface width W R is measurable along the radial tangent line (L R );
a bisector cutting sub-surface width W B is measurable along the bisector line (L B ); and
an axial cutting sub-surface width W A is measurable along the axial tangent line (L A );
wherein the rake ridge ( 30 C) of one or more of the teeth ( 34 ) is continuously curved from the bisector line (L B ) until at least an axial location rearward of the corner relief surface ( 28 C);
wherein the radial cutting sub-surface width W R and bisector cutting sub-surface width W B fulfill the condition: 0.9W B ≤W R ≤1.1W B .

2. The end mill ( 10 ) according to claim 1 , wherein, at an intersection of the radial and corner relief surfaces ( 28 B, 28 C), the radial and corner sub-edges ( 32 B, 32 C) form an external relief angle θ fulfilling the condition: 170°≤θ≤180°.

3. The end mill ( 10 ) according to claim 2 , wherein the external relief angle θ fulfills the condition: 178°≤θ≤180°.

4. The end mill ( 10 ) according to claim 1 , wherein each cutting sub-surface width W measurable between the rake ridge and the cutting edge, and taken between the radial tangent line and the bisector line, fulfills the condition: 0.9W B ≤W≤1.1W B .

5. The end mill ( 10 ) according to claim 1 , wherein the radial cutting sub-surface width W R and the axial cutting sub-surface width W A fulfill the condition: 0.9W A ≤W R ≤1.1W A .

6. The end mill ( 10 ) according to claim 1 , wherein each cutting sub-surface width W measurable between the rake ridge and the cutting edge, and taken between the radial tangent line and the axial tangent line, fulfills the condition: 0.9W A ≤W≤1.1W A .

7. The end mill ( 10 ) according to claim 1 , wherein at least one cutting sub-surface width W measurable between the rake ridge and the cutting edge, and taken between the axial tangent line and the bisector line, fulfills the condition: 0.008D E ≤W≤0.02D E .

8. The end mill ( 10 ) according to claim 7 , wherein each cutting sub-surface width W taken between the axial tangent line and the bisector line, fulfills the condition: 0.008D E ≤W≤0.02D E .

9. The end mill according to claim 8 , wherein each cutting sub-surface width W measurable between the axial tangent line and the radial tangent line, fulfills the condition: 0.008D E ≤W≤0.02D E .

10. The end mill ( 10 ) according to claim 1 , wherein each rake cutting sub-surface ( 30 A) is planar shaped.

11. The end mill ( 10 ) according to claim 1 , wherein the circle radius R C fulfills the condition: R C ≤0.08D E .

12. The end mill ( 10 ) according to claim 1 , wherein the cutting portion ( 20 ) comprises exactly either seven teeth ( 24 ) or nine teeth ( 24 ).

13. The end mill ( 10 ) according to claim 1 , wherein one or more of the teeth ( 24 ) has a radial rake angle β measurable along the radial tangent line (L R ) fulfilling the condition: −12°≤β≤7°.

14. The end mill ( 10 ) according to claim 13 , wherein each tooth ( 24 ) has a radial rake angle β measurable along the radial tangent line (L R ) fulfilling the condition: −5°≤β≤5°.

15. The end mill ( 10 ) according to claim 1 , wherein one or more of the teeth ( 24 ) has a radial rake angle β measurable along the radial tangent line (L R ) fulfilling the condition: β>0°.

16. The end mill ( 10 ) according to claim 1 , wherein one or more of the teeth ( 24 ) has a radial rake angle β measurable along the radial tangent line (L R ) fulfilling the condition: β<0°.

17. The end mill ( 10 ) according to claim 1 , wherein, at the front end ( 14 ), fewer than one-half the index angles have the same value.

18. The end mill ( 10 ) according to claim 17 , wherein each index angle S, in the middle of an effective length (L M ), has a value closer to a value equal to the total number of teeth ( 24 ) divided by 360, than a value of the same index angle S at the front end ( 14 ).

19. The end mill ( 10 ) according to claim 1 , wherein each tooth ( 24 ) has a rake ridge ( 30 C) which continuously curves from the bisector line (L B ) until at least an axial location rearward of the corner relief surface ( 28 C).

20. The end mill ( 10 ) according to claim 10 , wherein each tooth ( 24 ) has a rake ridge ( 30 C) which continuously curves from the bisector line (L B ) until at least an axial location rearward of the corner relief surface ( 28 C).

21. The end mill ( 10 ) according to claim 20 , wherein for each tooth, at an intersection of the radial and corner relief surfaces ( 28 B, 28 C), the radial and corner sub-edges ( 32 B, 32 C) form an external relief angle θ fulfilling the condition: 170°≤θ≤180°.

22. The end mill ( 10 ) according to claim 21 , wherein the external relief angle θ fulfills the condition: 178°≤θ≤180°.

Assignees

• Iscar Ltd

Inventors

• Shpigelman Leonid

Classifications

• B23C5/10 Primary

  Shank-type cutters, i.e. with an integral shaft · CPC title

• B23C2210/0414

  different · CPC title

• B23C2210/405

  having decreasing depth in the direction of the shank from the tip of the tool · CPC title

• B23C2210/082

  Details of the corner region between axial and radial cutting edges · CPC title

• B23C2210/206

  seven · CPC title