METAL CUTTING TOOL COMPRISING A VIBRATION DAMPING MEMBER

Abstract

A cutting tool for metal cutting includes a tool body having an insert seat and a recess formed therein. The tool body further includes vibration damping means. The vibration damping means have a cantilever member, the cantilever member being adjacent to the recess of the tool body. The cantilever member has a cantilever beam and an end mass, wherein the cantilever member extends between a fixed end and a free end. The fixed end is permanently connected to the tool body. The cantilever beam extends from the fixed end and the end mass extends from the free end.

Claims

1. A cutting tool for metal cutting, the cutting tool comprising: a tool body, the tool body including an insert seat; and a recess formed in the tool body, wherein the tool body includes vibration damping means, the vibration damping means including a cantilever member, the cantilever member being adjacent to the recess, wherein the cantilever member includes a cantilever beam and an end mass, the cantilever member extending between a fixed end and a free end, wherein the fixed end is permanently connected to the tool body, wherein the cantilever beam extends from the fixed end, and wherein the end mass extends from the free end.

2. The cutting tool according to claim 1, wherein the tool body includes a first side surface and an opposite second side surface, wherein the recess opens into the first and second side surfaces, and wherein the cantilever member extends between the first and second side surfaces.

3. The cutting tool according to claim 2, wherein a distance between the first and second side surfaces is 0.5-20 mm.

4. The cutting tool according to claim 2, wherein the first and second side surfaces are parallel or substantially parallel.

5. The cutting tool according to claim 2, further comprising a cutting insert positioned in the insert seat, wherein the cutting insert includes a cutting edge, wherein the cutting edge defines an insert width, and wherein the insert width is greater than a distance between the first and second side surfaces.

6. The cutting tool according to claim 5, wherein the tool body includes a front-end surface, wherein the insert seat opens into the front-end surface, wherein the cutting edge extends partly or completely in a common plane, and wherein a longitudinal axis of the cantilever beam extends in a plane parallel to or substantially parallel to said common plane.

7. The cutting tool according to claim 1, wherein the tool body includes a front-end surface, and wherein a distance from the front-end surface to the free end of the cantilever member is longer than a distance from the front-end surface to the fixed end of the cantilever member.

8. The cutting tool according to claim 1, wherein the tool body and the cantilever member are made from the same material.

9. The cutting tool according to claim 1, wherein the recess and the cantilever member have corresponding or substantially corresponding shapes, and wherein a gap width between the cantilever member and the surrounding portion of the tool body is constant or substantially constant.

10. The cutting tool according to claim 9, wherein the gap width is 0.2-5.0 mm.

11. The cutting tool according to claim 1, wherein the vibration damping means includes a kinetic energy absorbing element, the kinetic energy absorbing element being positioned in the recess.

12. The cutting tool according to claim 11, wherein the kinetic energy absorbing element is a polymer, an elastomer or a rubber.

13. The cutting tool according to claim 11, wherein the kinetic energy absorbing element has a hardness of 40-80, according to the ASTM D2240 type A scale.

14. The cutting tool according to claim 1, wherein a distance from the free end to a center of mass of the cantilever member is shorter than a distance from the fixed end to the center of mass of the cantilever member.

15. The cutting tool according to claim 1, wherein the cutting tool is a grooving blade, the grooving blade including a front-end surface, a top surface and a bottom surface, and wherein the insert seat opens into the front-end surface.

16. The cutting tool according to claim 15, wherein the top and bottom surfaces are parallel or substantially parallel, and wherein the cantilever beam is arranged parallel or substantially parallel to the top and bottom surfaces.

17. The cutting tool according to claim 15, wherein a distance from the front-end surface to the free end is longer than a distance from the front-end surface to the fixed end.

18. The cutting tool according to claim 15, wherein a distance from the front-end surface to the free end is shorter than a distance from the front-end surface to the fixed end.

19. The cutting tool according to claim 15, wherein a distance from the bottom surface to the cantilever member is shorter than a distance from the top surface to the cantilever member, and wherein a distance from the insert seat to the top surface is shorter than a distance from the insert seat to the bottom surface.

20. The cutting tool according to claim 1, wherein the cutting tool is a slot milling cutter, wherein the slot milling cutter is rotatable around a rotational axis, wherein the cantilever beam is arranged radially or substantially radially with regards to the rotational axis, and wherein the fixed end is facing the rotational axis.

21. A method to reduce vibrations during a metal cutting operation, comprising the steps of: providing a metal work piece; providing a cutting tool according to claim 5; rotating the metal work piece around a rotational axis thereof; arranging the cutting tool such that the cantilever beam is arranged radially or substantially radially with regards to the rotational axis; and cutting the metal work piece by moving the cutting tool towards the rotational axis.

Description

DESCRIPTION OF THE DRAWINGS

[0111] The present invention will now be explained in more detail by a description of embodiments of the invention and by reference to the accompanying drawings.

[0112] FIG. 1 is a perspective view of a tool adaptor and a cutting tool according to a first embodiment

[0113] FIG. 2 is a side view of the tool adaptor and the cutting tool in

[0114] FIG. 1 and a metal work piece

[0115] FIG. 3 is a side view of the cutting tool in FIG. 1

[0116] FIG. 4 is a top view of the cutting tool in FIG. 1

[0117] FIG. 5 is a perspective view of a tool adaptor and a cutting tool according to a second embodiment

[0118] FIG. 6 is a side view of the cutting tool in FIG. 5

[0119] FIG. 7 is a front view of the cutting tool in FIG. 5

[0120] FIG. 8 is a perspective view of a cutting tool according to a third embodiment

[0121] FIG. 9 is a perspective view of a cutting tool according to a fourth embodiment

[0122] FIG. 10 is a front view of the cutting tool in FIG. 9

[0123] FIG. 11 is a side view of the cutting tool in FIG. 9

[0124] FIG. 12 is a perspective view of a tool adaptor and a cutting tool according to a fifth embodiment

[0125] FIG. 13 is a side view of the cutting tool in FIG. 12

[0126] FIG. 14 is a magnified view of the bottom right portion of the cutting tool in FIG. 3 showing a first example of vibration damping means

[0127] FIG. 15 is a cross-sectional view along line A-A of FIG. 14

[0128] FIG. 16 is a cross-sectional view along line B-B of FIG. 14

[0129] FIG. 17 is a side view of a second example of vibration damping means

[0130] FIG. 18 is a side view of a third example of vibration damping means

[0131] FIG. 19 is a side view of a fourth example of vibration damping means

[0132] FIG. 20 is a side view of a cutting tool according to a sixth embodiment

[0133] FIG. 21 is a magnified view of the bottom right portion of the cutting tool in FIG. 20 showing a fifth example of vibration damping means

[0134] FIG. 22 is a cross-sectional view along line A-A of FIG. 21

[0135] FIG. 23 is a cross-sectional view along line B-B of FIG. 21

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

[0136] Reference is made to FIGS. 1-4 which show a cutting tool 1 according to a first embodiment.

[0137] The cutting tool 1 comprises a tool body 2 in the form of an elongated parting and grooving blade and a cutting insert 18. The tool body 2 comprise two diagonally opposite insert seats 11. The cutting insert 18 is mounted in one insert seat 11.

[0138] Two recesses 9 is formed in the tool body 2. One recess 9 is described more in detail in FIGS. 14-16. The tool body 2 comprises vibration damping means 4, where the vibration damping means 4 comprises a cantilever member 12 adjacent to the recess 9.

[0139] The cutting insert 3 comprises a top surface 29, an opposite bottom surface 30 and a front-end surface 40. A cutting edge 19 connects the front-end surface 40 and the top surface 29. The cutting edge 19 defines an insert width 20. The front-end surface is a clearance surface or relief surface. The top surface 29 of the cutting insert comprises chip breaking means in the form of one or more protrusions and/or depressions. The top surface 29 is suitable to function as a rake surface. The top and bottom surfaces 29, 30 comprises seating surfaces for contact with seating surfaces formed in the insert seat 11.

[0140] The tool body 2 comprises a front-end surface 21, an opposite rear surface 33, a top surface 22, an opposite bottom surface 23, a first side surface 15 and an opposite second side surface 16. The tool body 2 is elongated, i.e. a distance from the front-end surface 21 to the rear surface is greater than a distance from the top surface 22 to the bottom surface 23.

[0141] The bottom surface is V-shaped, i.e. tapered. The bottom surface 23 comprises a first surface 31 and a second surface 32, wherein the first and second surface forms an angle of 100-170°, even more preferably 110-150°, in relation to each other. A height of the grooving blade defined as a distance between the top and bottom surfaces 22, 23, is greater mid-way between the first and second side surface 15, 16 than at or along the first or second side surface 15, 16. The top surface 22 is arranged in a corresponding manner as the bottom surface 23.

[0142] The insert seat 11 opens into the front-end surface 21.

[0143] A longitudinal axis A1 of the cantilever beam is parallel to or substantially parallel to the top and bottom surfaces 22, 23 seen in a side view as seen in e.g. FIG. 3.

[0144] A distance 17 between the first and second side surfaces 15, 16 is constant and smaller than the insert width 20.

[0145] As seen in FIGS. 1 and 2, the cutting tool 1 is mounted in a tool adaptor 25 by clamping means 26 which include screws. The tool adaptor comprises a coupling portion 24 suitable for connection to a machine interface 27 of a machine tool (not shown), such as e.g. a CNC-lathe.

[0146] FIG. 2 show an example of how the cutting tool 1 is used when machining a metal work piece 28 in a parting-off or radial grooving operation. The metal work piece 28 rotates around a rotational axis R2 thereof. The direction of rotation of the metal work piece 28 is counter clock-wise in FIG. 2. The cutting tool 1 is brought or moved towards the metal work piece 28 in a radial grooving direction 34. More precisely, the cutting edge 19 of the cutting insert 1 is linearly towards the rotational axis R2 of the metal work piece 28. The longitudinal axis A1 of the cantilever beam is parallel to or substantially parallel to the radial grooving direction 34.

[0147] In an alternative embodiment (not shown), the metal work piece 28 may be still while the cutting tool 1 rotates around the rotational axis R2 of the metal work piece 28.

[0148] Reference is now made to FIGS. 5-7 which show a cutting tool 1 according to a second embodiment. The cutting tool 1 comprises a tool body 2 and a cutting insert 18. The cutting insert 18 is identical to the cutting insert 18 in FIGS. 1-4. The cutting tool 1 mounted in a tool adaptor 25, which tool adaptor 25 is identical to the tool adaptor in FIGS. 1 and 2. The tool body 2 differs from the tool body 2 shown in FIGS. 1-4 in that the insert seat is oriented such that the front end 40 of cutting insert 18 and the bottom surface 23 is facing the same direction or substantially the same direction. The longitudinal axis A1 of the cantilever beam is perpendicular to the top and bottom surfaces 22, 23.

[0149] Reference is now made to FIG. 8 which show a cutting tool 1 according to a third embodiment. The cutting tool 1 differs from the cutting tool shown in FIGS. 5-7 in that the tool body 2 comprises a blade portion 41, or a front portion, and a rear portion 42. The blade portion 41 comprises the first side surface and the second side surface 16. A distance between the first and second side surfaces is constant and smaller than the insert width. The blade portion 41 comprises the cantilever member 12. The rear portion 42 comprises a coupling portion 24.

[0150] Reference is now made to FIGS. 9-11 which show a cutting tool 1 according to a fourth embodiment. The tool body 2 comprises a blade portion 41, or a front portion, and a rear portion 42. The blade portion 41 comprises the first and second side surfaces 15, 16. A distance 17 between the first and second side surfaces 15, 16 is smaller than the insert width 20. The first and second side surfaces 15, 16 is curved or arc-shaped in a front view, as seen in FIG. 10.

[0151] Reference is now made to FIGS. 12 and 13 which show a cutting tool 1 according to a fifth embodiment. The cutting tool 1 is a slot milling cutter or a grooving milling cutter, which is rotatable around a rotational axis R1 thereof. The cutting tool 1 is suitable for machining a groove in a metal work piece (not shown).

[0152] As seen in FIG. 12, the cutting tool 1 is mountable in a tool adaptor 25 by clamping means 26 which include screws. The tool adaptor 25 comprises a coupling portion 24 suitable for connection to a machine interface 27 of a machine tool (not shown), such as e.g. a machining center or a multi-task machine, or any CNC machine having capacity to rotate a milling tool.

[0153] As seen in FIG. 13, the cantilever member 12 is arranged such that the cantilever beam is arranged radially or substantially radially with regards to the rotational axis R1, such that a longitudinal axis A1 of cantilever beam intersects or substantially intersects the rotational axis A1 of the slot milling cutter. The cantilever member 12 is spaced apart from the rotational axis R1.

[0154] The slot milling cutter 1 comprises 15 insert seats evenly or substantially evenly arranged around the rotational axis R1 when seen in a side view as in FIG. 13. Exactly one cutting insert 18 is positioned in each insert seat. The number of vibration damping means is equal to the number of insert seats.

[0155] The slot milling cutter 1 comprises 15 cutting inserts 18 and 15 insert seats. However, the number of cutting inserts may be smaller or larger.

[0156] Reference is now made to FIG. 14-16 which more in detail show the first example of vibration damping means found in the bottom right portion of the cutting tool in FIG. 3. FIG. 15 is a cross-sectional view along line A-A of FIG. 14. FIG. 16 is a cross-sectional view along line B-B of FIG. 14. The vibration damping means 4 comprise a cantilever member 12.

[0157] The cantilever member 12 is adjacent to the recess 9. The recess 9 opens into the first side surface 15, and into the opposite second side surface 16. The cantilever member 12 comprises a rectangular cuboid shaped cantilever beam 5 and a cylinder-shaped end mass 8. The cantilever member 12 extends between a fixed end 6 and a free end 7. The fixed end 6 is permanently connected to the tool body 2. The cantilever beam 5 extends from the fixed end 6. The end mass 8 extends from the free end 7.

[0158] A longitudinal axis A1 or central axis of cantilever beam 5 intersects the fixed end 6 and the free end 7. The longitudinal axis A1 is parallel to the bottom surface 23 of the tool body 23. The longitudinal axis A1 is perpendicular to the front-end surface 21.

[0159] A cross section area of the cantilever member 12 is greater at a mid-section of the cantilever beam 5, seen in FIG. 15, than at a mid-section of the end mass 8, as seen in FIG. 16.

[0160] A distance from the front-end surface 21 to the free end 7 of the cantilever member 12 is shorter than a distance from the front-end surface 21 to the fixed end 6 of the cantilever member 12. A gap width 13, or recess width, between the cantilever member 12 and the surrounding portion of the tool body 2, made from the same material as the cantilever member 12, is constant or substantially constant. A height 35 of cantilever beam 5 is constant and is measured perpendicular to the longitudinal axis A1 of the cantilever beam 5, as seen in FIG. 14. A length 36 of the cantilever beam 5 and a length 37 of the end mass 8 are both measured along the longitudinal axis A1 of the cantilever beam 5. A height 38 of the end mass 8 is measured perpendicular to the longitudinal axis A1 of the cantilever beam 5, as seen in FIG. 14. A length 39 of the cantilever member 12 is equal to the combined lengths 36, 37 of the cantilever beam 5 and the end mass 8. A width of the cantilever member 12 is constant and equal to the distance 17 between the first and second side surfaces 15, 16.

[0161] Preferably a distance from the recess 9 to the front-end surface 21 is 2-6 mm.

[0162] Reference is now made to now made to FIG. 17, showing a second example of vibration damping means 4. The only difference compared to the first example of vibration damping means is that a kinetic energy absorbing element 14 is positioned in a portion of the recess 9. More precisely, the recess 9 surrounding the end mass 8 is at least partly filled with the kinetic energy absorbing element 14. The kinetic energy absorbing element 14 is silicone. The kinetic energy absorbing element extends between or substantially between the first and second side surfaces.

[0163] Reference is now made to now made to FIG. 18, showing a third example of vibration damping means 4. The main differences compared to the first example of vibration damping means is that gap width 13 varies, and that the shape of the recess 9 is such that the end mass 8 is oval shaped in a side view.

[0164] Reference is now made to now made to FIG. 19, showing a fourth example of vibration damping means 4. The main differences compared to the first example of vibration damping means is that gap width 13 varies, and that the shape of the recess 9 differs. More specifically, the height 35 of cantilever beam 5 is increasing at increasing distance from the fixed end 6, and the cantilever beam is seamlessly transitioned into the end mass 8.

[0165] Reference is now made to FIG. 20 which show a sixth embodiment of a cutting tool comprising a fifth example of vibration damping means 4, shown in detail in FIGS. 21-23. The main differences compared to the first example of vibration damping means is that the orientation of the cantilever member 12 is rotated 180° in a side view, as seen in FIG. 22. A distance from the front-end surface 21 to the free end 7 of the cantilever member 12 is greater than a distance from the front-end surface 21 to the fixed end 6 of the cantilever member 12. Further differences are that a length 36 of the cantilever beam 5 is shorter than a length 37 of the end mass 8, and that the gap width 13 is greater.

[0166] The longitudinal axis A1 of cantilever beam 12 is parallel to the top and bottom surfaces 22, 23 of the tool body 2. The recess is preferably positioned such that distances from the recess 9 to the bottom surface 23, the front-end surface 21 and the insert seat 11, respectively, are substantially equal, i.e. none of said distances is more than 100%, preferably 50%, greater than any other of said distances. This can be understood from e.g. FIG. 21, where said distances are substantially equal. Preferably, a distance from the recess 9 to the bottom surface is 2-6 mm. Preferably a distance from the recess 9 to the front-end surface 21 is 2-6 mm. Preferably, a distance from the recess 9 to the insert seat 11 is 2-6 mm.

[0167] All the above examples of vibration damping means may include a kinetic energy absorbing element 14, preferably comprising silicone, positioned in at least a portion of the recess 9, preferably such that the recess 9 surrounding the end mass 8 is at least partly filled with the kinetic energy absorbing element 14.

[0168] All the above examples of vibration damping means may include a high density material, i.e. of higher density than steel, preferably cemented carbide, connected to the end mass.

[0169] Any of the above described vibration damping means can be utilized for any of the above described cutting tools.

[0170] The cutting insert shown in the above embodiment may have other shapes, such as substantially L-shaped or triangular in a side view. The clamping of the insert can be through spring clamp, i.e. through the inherent elasticity of a clamping jaw, insert screw, top clamp, or any other suitable clamping means.

[0171] The recess in the above described cutting tools may be formed through any suitable metal removal operation, such as milling, drilling, electrical discharge machining (EDM) or laser.

[0172] Other examples of cutting tools (not shown) may comprise a recess in the form of a cavity, which is spaced apart from the first and second side surfaces. Such cutting tools may preferably be formed completely or partially through additive manufacturing.