Granted Patent B2

US 12,257,637 · App. 17/706,265 · Granted Mar 25, 2025

Inventor: Ruy Frota de Souza Filho (Latrobe, PA)

Assignee: KENNAMETAL INC.

B23C5/003B23C5/28

Abstract

Claims (33)

1. A rotary cutting tool, comprising:

a shank portion;

a cutting portion adjoining the shank portion and having a cutting end, the cutting portion having a plurality of blades separated by helically twisted flutes, each blade including a leading face, a trailing face, and a land surface extending between the leading face and the trailing face; and

a tunable vibration absorber disposed within an internal cavity formed in the cutting portion, the internal cavity having a helical shape that corresponds with the shape of the helically twisted flutes, the tunable vibration absorber has a corresponding helical shape to the internal cavity helical shape, the tunable vibration absorber comprising an absorber mass and a resilient material disposed between the absorber mass and a wall of the internal cavity,

wherein the internal cavity has a first diameter section disposed within the shank portion and having a length, L1, and a second diameter section adjoining the first diameter section for receiving the tunable vibration absorber, the first diameter section having a first diameter and the second diameter section having a second diameter smaller in magnitude than the first diameter, the second diameter section having a total length equal to L2+L3+G, where L3 is a length of the tunable vibration absorber, L2 is a length of the internal cavity without the tunable vibration absorber located between the first diameter section and the tunable vibration absorber, and G is a length of a gap between the tunable vibration absorber and an end wall of the internal cavity,

wherein L2 is greater than L3,

wherein the lengths L1, L2, L3 and G are measured in a direction parallel to a central, longitudinal axis, C L , of the rotary cutting tool,

wherein the helical shape of the internal cavity extends over a length, measured in the direction parallel to the central, longitudinal axis, C L , of the rotary cutting tool, greater than the length L3,

wherein the tunable vibration absorber is tuned to a desired frequency by selecting mechanical properties of the absorber mass and the resilient material, and

wherein the desired frequency of the tunable vibration absorber causes destructive interference between the tunable vibration absorber and the rotary cutting tool, thereby suppressing vibration of the rotary cutting tool during a cutting operation.

2. The rotary cutting tool of claim 1 , wherein the internal cavity corresponds with the shape of the helically twisted flutes in such a way that a distance, CD, between a bottom of at least one of the plurality of flutes and the wall of the internal cavity is substantially constant along the length, L3, of the tunable vibration absorber.

3. The rotary cutting tool of claim 1 , wherein the resilient material has a thickness that is constant along the length, L3, of the tuned vibration absorber.

4. The rotary cutting tool of claim 1 , wherein the tunable dynamic absorber comprises a main internal fluid cavity.

5. The rotary cutting tool of claim 4 , wherein the main internal fluid cavity is coaxial with respect to the central, longitudinal axis, C L , of the rotary cutting tool.

6. The rotary cutting tool of claim 4 , wherein the tunable dynamic absorber further comprises a plurality of secondary internal fluid cavities extending radially outward from the main internal fluid cavity to the resilient material.

7. The rotary cutting tool of claim 6 , wherein each of the plurality of secondary internal fluid cavities are substantially perpendicular to a central, longitudinal axis, C L , of the rotary cutting tool.

8. The rotary cutting tool of claim 6 , wherein the main internal fluid cavity has a larger cross-sectional area than each of the plurality of secondary fluid cavities.

9. The rotary cutting tool of claim 1 , wherein the tunable vibration absorber is formed by additive manufacturing.

10. The rotary cutting tool of claim 1 , wherein the rotary cutting tool is an end mill.

11. A rotary cutting tool, comprising:

a shank portion;

a cutting portion adjoining the shank portion and having a cutting end, the cutting portion having a plurality of blades separated by helically twisted flutes; and

a tunable vibration absorber disposed within an internal cavity formed in the cutting portion, the internal cavity having a helical shape that corresponds with the shape of the helically twisted flutes, the tunable vibration absorber has a corresponding helical shape to the internal cavity helical shape, the tunable vibration absorber comprising an absorber mass and a resilient material disposed between the absorber mass and a wall of the internal cavity, the tunable dynamic absorber includes a main internal fluid cavity coaxial with respect to a central, longitudinal axis, C L , of the rotary cutting tool,

wherein the internal cavity has a first diameter section disposed within the shank portion and having a length, L1, and a second diameter section adjoining the first diameter section for receiving the tunable vibration absorber, the first diameter section having a first diameter and the second diameter section having a second diameter smaller in magnitude than the first diameter, the second diameter section having a total length equal to L2+L3+G, where L3 is a length of the tunable vibration absorber, L2 is a length of the internal cavity without the tunable vibration absorber located between the first diameter section and the tunable vibration absorber, and G is a length of a gap between the tun-able vibration absorber and an end wall of the internal cavity,

wherein L2 is greater than L3,

wherein the lengths L1, L2, L3 and G are measured in a direction parallel to the central, longitudinal axis, C L , of the rotary cutting tool,

wherein the helical shape of the internal cavity extends over a length, measured in the direction parallel to the central, longitudinal axis, C L , of the rotary cutting tool, greater than the length L3, and

wherein the tunable vibration absorber is tuned by controlling a fluid pressure within the main internal cavity.

12. The rotary cutting tool of claim 11 , wherein the tunable vibration absorber further comprises a plurality of secondary internal fluid cavities extending radially outward from the main internal fluid cavity to the resilient material.

13. The rotary cutting tool of claim 11 , wherein mechanical properties of the absorber mass and the resilient material are selected in such a way as to the enable the tunable vibration absorber to be tuned to a desired frequency, and

wherein the desired frequency of the tunable vibration absorber causes destructive in-terference between the tunable vibration absorber and the rotary cutting tool, thereby sup-pressing vibration of the rotary cutting tool during a cutting operation.

14. The rotary cutting tool of claim 11 , wherein the main internal fluid cavity is in fluid communication with a fluid exit bore to provide fluid to a tool/workpiece interface at the cutting end of the rotary cutting tool.

15. The rotary cutting tool of claim 11 , wherein the cutting portion comprises a plurality of blades separated by helically twisted flutes, each blade including a leading face, a trailing face, and a land surface extending between the leading face and the trailing face.

Assignments (1)

Continuity (1)

References Cited (39)