ROTARY CUTTING TOOL WITH HONE EDGES

• US 20150367427A1
• Filed: 06/17/2015
• Published: 12/24/2015
• Est. Priority Date: 06/18/2014
• Status: Active Grant

• Current Assignee: KYOCERA SGS Precision Tools, Inc. (Kyocera Corporation)
• Original Assignee: SGS Tool Co (Kyocera Corporation)
• Inventors: Burton, Jeffery L., Bonfiglio, Douglas P., Rak, Jake
• Granted Patent: US 10,058,934 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B23C 2210/0407 Cutting angles
• CPC Class Codes: B23C 2210/0485 Helix angles
• CPC Class Codes: B23C 2210/126 Rounded cutting edges
• CPC Class Codes: B23C 5/10 Shank-type cutters, i.e. with an integral shaft
• CPC Class Codes: B24B 3/021 of milling cutters with helical cutting edges
• CPC Class Codes: B24B 3/06 of face or end milling cutters or cutter heads, e.g. of shank type
• CPC Class Codes: Y10T 407/1948 with cutting edge entirely across end of tool [e.g., router bit, end mill, etc.]

Abstract

A rotary cutting tool includes a shaft having and outer surface and having a longitudinal axis, a plurality of helical flutes formed in the shaft about the longitudinal axis, a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis, and a plurality of end cutting edges located on an axial distal end of a cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges. A hone edge extends along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

Claims

1. An end mill rotary cutting tool comprising:

a shaft having and outer surface and having a longitudinal axis, the shaft including a shank portion and cutting portion;

a plurality of helical flutes formed in the shaft in the cutting portion about the longitudinal axis; and

a plurality of helical cutting edges formed at an interface with the outer surface and a respective helical flute about the longitudinal axis;

a plurality of end cutting edges located on an axial distal end of cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges; and

a hone edge extending along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

2. The end mill of claim 1 where the hone edges are all varying hone edges.

3. The end mill of claim 2 where the varying hone edges increase from the associated helical cutting edge toward the associated end cutting edge.

4. The end mill of claim 2 where the helix angle of the helical flutes varies along the longitudinal axis.

5. The end mill of claim 2 where the rake angle of the helical cutting edges varies along the longitudinal axis.

6. The end mill of claim 2 where there is increased honing on the corners as compared to the helical cutting edges.

7. The end mill of claim 2 where there is increased honing on the corners as compared to the end cutting edges and the helical cutting edges.

8. The end mill of claim 2 where the hone edges are all geometrically positive.

9. A method of forming a rotary cutting tool comprising:

providing a shaft having and outer surface and having a longitudinal axis

forming a plurality of helical flutes in the shaft about the longitudinal axis defining a cutting portion, the remainder of the shaft defining a shank portion;

forming a plurality of helical cutting edges at an interface with the outer surface and a respective helical flute about the longitudinal axis;

forming a plurality of end cutting edges on an axial distal end of cutting portion of the shaft, the end cutting edges being contiguous with a corresponding one of the plurality of helical cutting edges and forming a corner in the transition between each of the end cutting edges and the corresponding one of the plurality of helical cutting edges; and

forming a hone edge extending along a portion of each of the end cutting edges, the associated corner and a portion of the corresponding one of the plurality of helical cutting edges.

10. The method of claim 9 further comprising, prior to forming the hone edges, securing the shaft in chuck at the shank portion.

11. The method of claim 10 where the forming the hone edges includes rotating the shaft by the chuck.

12. The method of claim 9 further comprising,

providing a machining brush, and

where in the forming the hone edges includes applying the brush to the helical cutting edges.

13. The method of claim 9 where the brush includes filaments flanged between two disks.

14. The Method of claim 9 further comprising,

providing a machining brush, and

where in the forming the hone edges includes applying the brush to the end cutting edges.

15. The method of claim 14 where the brush includes filaments flanged between two disks.

16. The method of claim 11 where the hone edges are varying hone edges.

17. The method of claim 16 where the varying hone edges increase from the associated helical cutting edge toward the associated end cutting edge.

18. The method of claim 16 where there is increased honing on the corners as compared to the helical cutting edges.

19. The method of claim 9 where the forming hone edges is performed by a CNC machine.