CUTTING TOOL ASSEMBLY WITH ADJUSTABLE DAMPERS

Abstract

A boring bar has a generally cylindrical elongate tool body has a proximal end for mounting to drive unit and a distal end for attachment to a tool head. A passageway extends longitudinally along the central axis of the elongate tool body. A plurality of longitudinally extending cavities are disposed annularly about the tool body. A compressive material is disposed in each of the cavities. An adjustable compression fitting is disposed in at least one end of each of the cavities, where each of the compression fitting can be adjusted to change compression of the material disposed in a respective cavity.

Claims

1. A boring bar comprising: a generally cylindrical elongate tool body having a proximal end for mounting to drive unit and a distal end for attachment to a tool head, with a passageway extending longitudinally along the central axis of the elongate tool body, and a having a plurality of longitudinally extending cavities disposed annularly about the tool body; a compressive material disposed in each of the cavities; and an adjustable compression fitting disposed in at least one end of each of the cavities, where each of the compression fitting can be adjusted to change compression of the material disposed in a respective cavity.

2. The boring bar of claim 1 where the adjustable compression fitting is a screw mechanism.

3. The boring bar of claim 1 where the adjustable compression fitting is a fluid driven element that is one of hydraulically and pneumatically controlled.

4. The boring bar of claim 1 where the cavities are disposed about equal angular spacing of the tool body.

5. The boring bar of claim 1 where the cavities are disposed at equal radial distance from the central axis of the tool body.

6. The boring bar of claim 1 where the cavities extend from the proximal end to the distal end.

7. The boring bar of claim 6 where the cavities have adjustable compression fittings disposed in both the proximal ends and the distal ends of each of the cavities.

8. The boring bar of claim 1 where the compressive material includes particles of differing sizes, where the size of the particles ranges in the size of 0.20 to 6.0 microns.

9. The boring bar of claim 8 where the compressive material is limited to particles that range in the size of 0.20 to 0.75 microns.

10. The boring bar of claim 8 where the compressive material is limited to particles that range in the size of 1.3 to 6.0 microns.

11. The boring bar of claim 8 where the compressive material is a multi-phase material including the particles of differing sizes in solid state and including a liquid, where the particles and the liquid form a slurry.

12. The boring bar of claim 1 where the compressive material includes particles of differing shapes.

13. The boring bar of claim 12 where the differing shapes include at least one of spherical, droplet, diamond, and pyramidal.

14. The boring bar of claim 1 where the compressive material includes particles of differing surface finish.

15. The boring bar of claim 1 where the compressive material includes particles of differing substances.

16. The boring bar of claim 15 where the differing substances include at least one of aluminum, copper, zinc, iron, steel, and carbide.

17. A tool for cutting tool operation comprising: a generally cylindrical elongate tool body having a proximal end for mounting to drive unit and a distal end for attachment to a tool head, with a passageway extending longitudinally along the central axis of the elongate tool body, and a having a plurality of longitudinally extending cavities disposed annularly about the tool body; a compressive material disposed in each of the cavities; and an adjustable compression fitting disposed in at least one end of each of the cavities, where each of the compression fitting can be adjusted to change compression of the material disposed in a respective cavity. a tool head adapted to receive a cutting element attached to distal end of the tool body and including a passageway in communication with the passageway of the tool body for the delivery of fluid to a work piece, and a cutting element disposed on the tool head.

18. The tool of claim 17 where the adjustable compression fittings are disposed at the proximal ends of each of the cavities.

19. The tool of claim 17 further comprising a generally cylindrical insert disposed within the passageway of the tool body and extending longitudinally along the central axis of the elongate tool body, where insert has a higher density than the tool body.

20. The tool of claim 16 where the cavities extend from the proximal end, and where the cavities each have an adjustable compression fitting disposed in the proximal end of each of the cavities.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] FIG. 1 is a top side perspective view of a tool assembly with adjustable dampers.

[0020] FIG. 2 is a top view of the tool assembly of FIG. 1.

[0021] FIG. 3 is a partial side schematic view of the tool assembly holder of FIG. 1.

[0022] FIG. 4 is a side cross-sectional view of the tool assembly of FIG. 1 taken along line 4-4 in FIG. 3.

DETAILED DESCRIPTION

[0023] Referring now to the drawings, there is illustrated in FIGS. 1-4, a tool assembly 110 for a cutting tool operation includes a generally cylindrical elongate tool body 112, i.e. a boring bar, having a proximal end 114 for connection to a drive unit and a distal end 116 for connection to a tool head or tool insert holder 118. A cutting element or tool insert 120 is disposed on the tool head 118.

[0024] The generally cylindrical elongate tool body 112 includes an outer main body 121 having a passageway 122 extending longitudinally along the central axis A of the elongate tool body 112 from the proximal end 114 to the distal end 116.

[0025] The tool head 118, adapted to receive the cutting element 120 and attached to the distal end 116 of the tool body 112, includes a passageway 130 in communication with the passageway 122 of the tool body 112 for the delivery of fluid to a work piece.

[0026] A plurality of longitudinally extending cavities 124 are disposed annularly about the tool body 112. A compressive material 126 is disposed in each of the cavities 124. An adjustable compression fitting 128 is disposed in at least one end of each of the cavities 124. Each of the compression fittings 128 can be adjusted to change compression of the material 126 disposed in a respective cavity 124.

[0027] In at least one embodiment, the cavities 124 extend from the proximal end 114 and extend into the tool body 112 and may extend to the distal end 116. In this example, each cavity 124 preferably has an adjustable compression fitting 128 disposed in the proximal end of each of the cavities 124, as to be accessible even when the tool head 118 is connected to the tool body 112. Although, each cavity may have an adjustable compression fitting 128 at either or both ends.

[0028] In at least one embodiment, the adjustable compression fitting 128 is a screw mechanism that may interact with threads disposed in the tool body 112 or cooperate with threads in a threaded insert placed in the cavity 124. In at least one other embodiment, the adjustable compression fitting 128 is a fluid driven element that may be hydraulically or pneumatically controlled.

[0029] The cavities 124 may be disposed about equal angular spacing of the tool body. Additionally, or alternatively, the cavities 124 may be disposed at equal radial distance from the central axis A of the tool body 112.

[0030] The compressive material 126 may include particles of differing sizes. For example, the compressive material 126 may include particles that range in the size of 0.20 to 0.75 microns, and/or particles that range in the size of 1.3 to 6.0 microns. In a number of embodiments, the compressive material 126 is a multi-phase material including the particles of differing sizes in solid state and including a liquid, with the particles and the liquid form a slurry.

[0031] Further, the compressive material 126 may include particles of differing shapes. For example, the differing shapes may include at least two of spherical, droplet, diamond, and pyramidal.

[0032] Additionally, the compressive material 126 may include particles of differing surface finish.

[0033] The compressive material 126 may include particles of differing substances. For example, the differing substances may include at least two of aluminum, copper, zinc, iron, steel, and carbide, or other heavy metal.

[0034] In one operation, the compressive material 126 can be tuned, i.e. subject to increased or decreased compression, by adjusting the adjustable compression fittings 128. It is expected that such will adjust the density of particles of the compressive material 126, which will modify the static and or dynamic stiffness of the boring bar 112, and reduce the chatter in a milling operation. It is further expected that such operation will change the radial pressure created by the compressive material 126 in the cavities 124. Thus, the stiffness of the boring bar 112 can be varied by adjusting the compression and/or compacting of the compressive material 126 with the adjustable compression fittings 128. It must be understood that density of the compressive material 126 prior to any action by the compression fittings 128 may be a relatively low-density or high-density material as desired for a particular tool assembly 110.

[0035] As illustrated, an optional generally cylindrical insert 132 is disposed within the passageway 122 of the tool body 112 and extends longitudinally along the central axis A of the elongate tool body 112. The insert 132 preferably has a higher density than the tool body 112. For example, the tool body 112 may be made of a carbon steel and the insert 132 may be made of a carbide material. It is expected that inclusion of the insert 132 will improve the stiffness of the overall tool assembly 110, as compared to an assembly with out the insert 132.

[0036] In one embodiment, the boring bar 112 is a higher L/D ratio boring bar, e.g. a L/D ration of 4 or more, and preferably in the range of 4 to 10. In one particular embodiment, the boring bar 112 has a length of at least 20 mm.

[0037] While principles and modes of operation have been explained and illustrated with regard to particular embodiments, it must be understood, however, that this may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.