Rotary cutting tool and cutting tool parts

Abstract

The invention describes a rotary cutting tool, in particular a drill, which comprises a first cutting tool part having at least one cutting edge and a second cutting tool part which comprises a cutting tool shank. The first cutting tool part and the second cutting tool part are releasably connected to one another via a coupling mechanism which comprises a coupling cam that is mounted on one of the two cutting tool parts such that it can rotate about an axis of rotation and, in a coupling position, abuts an engagement surface on the other cutting tool part. The invention also presents a cutting tool part, in particular a cutting tool base, and a further cutting tool part, in particular a cutting tip.

Claims

1. A rotary cutting tool comprising: a first cutting tool part on which at least one cutting edge is disposed and a second cutting tool part which comprises a cutting tool shank, wherein the first cutting tool part and the second cutting tool part are adjacent to one another along an axis of rotation of the rotary cutting tool and are releasably connected to one another via a coupling mechanism, wherein the coupling mechanism comprises a coupling cam that is mounted on one of the two cutting tool parts such that it can rotate about an axis of rotation and, in a coupling position, abuts an engagement surface on the other cutting tool part, so that the first cutting tool part and the second cutting tool part are coupled in the direction of the axis of rotation.

2. The rotary cutting tool according to claim 1, wherein, in the coupling position of the coupling cam, the first cutting tool part and the second cutting tool part are coupled in a form-locking manner in the direction of the axis of rotation.

3. The rotary cutting tool according to claim 1, wherein the axis of rotation of the coupling cam extends transverse to the axis of rotation of the rotary cutting tool.

4. The rotary cutting tool according to claim 1, wherein the coupling cam is substantially elliptical or parabolic in a cross-section oriented substantially perpendicular to the axis of rotation.

5. The rotary cutting tool according to claim 1, wherein the coupling cam is disposed in an end portion of the first cutting tool part or the second cutting tool part facing the respective other cutting tool part.

6. The rotary cutting tool according to claim 1, wherein the coupling cam is seated on a camshaft that is mounted within the first cutting tool part or the second cutting tool part such that it can rotate about the axis of rotation.

7. The rotary cutting tool according to claim 6, wherein the coupling cam is produced in one piece with the camshaft or is integrally connected to the camshaft.

8. The rotary cutting tool according to claim 1, wherein the engagement surface forms an undercut which acts in the direction of the axis of rotation of the rotary cutting tool and in a separating direction of the cutting tool parts.

9. The rotary cutting tool according to claim 1, wherein the engagement surface comprises a cylinder jacket surface portion.

10. The rotary cutting tool according to claim 9, wherein a central axis associated with the cylinder jacket surface portion extends transverse to the axis of rotation of the rotary cutting tool.

11. The rotary cutting tool of claim 1, wherein the engagement surface is configured as a section of a coupling groove, wherein the coupling groove is provided on the first cutting tool part or on the second cutting tool part and an opening of the coupling groove faces in the direction of the respective other cutting tool part.

12. The rotary cutting tool according to claim 11, wherein the engagement surface is disposed in the region of a groove base of the coupling groove.

13. The rotary cutting tool according to claim 11, wherein the coupling cam and the coupling groove are matched to one another such that, in an assembly position, the coupling cam can be slid along the axis of rotation of the rotary cutting tool inside the coupling groove.

14. A cutting tool part for a rotary cutting tool according to claim 1 comprising a coupling interface for coupling the cutting tool part to another cutting tool part, wherein the coupling interface comprises a rotatably mounted coupling cam.

15. A cutting tool part for a rotary cutting tool according to claim 1 comprising a coupling interface for coupling the cutting tool part to another cutting tool part, wherein the coupling interface comprises an engagement surface for a coupling cam.

16. The rotary cutting tool according to claim 1, wherein the rotary cutting tool is a drill.

17. The rotary cutting tool according to claim 3, wherein the axis of rotation of the coupling cam extends normal to the axis of rotation of the rotary cutting tool.

18. The rotary cutting tool according to claim 6, wherein a tool engagement contour is provided on at least one end of the camshaft.

19. The rotary cutting tool according to claim 9, wherein the cylinder jacket portion is a circular cylinder jacket surface portion or a jacket surface portion of a cylinder having an elliptical bottom surface.

20. The rotary cutting tool of claim 10, wherein the central axis extends substantially parallel to the axis of rotation of the coupling cam.

Description

DETAILED DESCRIPTION

[0032] The invention is explained below with the aid of a design example, which is shown in the accompanying drawings. The figures show:

[0033] FIG. 1 in a schematic side view, a rotary cutting tool according to the invention composed of two cutting tool parts according to the invention,

[0034] FIG. 2 a detail II of the rotary cutting tool of FIG. 1 in a perspective view,

[0035] FIG. 3 a diametric section through the portion of the rotary cutting tool shown in FIG. 2, wherein a coupling cam is in an assembly position,

[0036] FIG. 4 a sectional view corresponding to FIG. 3, wherein the coupling cam is in a coupling position,

[0037] FIG. 5 a portion of one of the cutting tool parts according to the invention of the rotary cutting tool of FIG. 1 comprising a coupling interface,

[0038] FIG. 6 the other cutting tool part according to the invention of the rotary cutting tool of FIG. 1, and

[0039] FIG. 7 a composite consisting of a coupling cam and a camshaft of the rotary cutting tool of FIG. 1 in an isolated illustration.

[0040] FIG. 1 shows a rotary cutting tool 10 which, in the embodiment shown, is a drill.

[0041] The rotary cutting tool 10 comprises a first cutting tool part 12 on which a cutting edge 14 is disposed. The first cutting tool part 12 can therefore also be referred to as the cutting tip.

[0042] The rotary cutting tool 10 also comprises a second cutting tool part 16 which comprises a cutting tool shank 18. In simplified form, the second cutting tool part 16 can therefore be referred to as a cutting tool base or cutting tool shank.

[0043] The first cutting tool part 12 and the second cutting tool part 16 are disposed adjacent one another along an axis of rotation 20 of the rotary cutting tool 10 and releasably connected to one another via a coupling mechanism 22.

[0044] The coupling mechanism 22 is discussed in more detail below with reference to FIGS. 2 to 7.

[0045] In this regard, the second cutting tool part 16 comprises a coupling interface 24 for coupling with the first cutting tool part 12 (see in particular the isolated illustration in FIG. 5).

[0046] The coupling interface 24 comprises an axially oriented abutment surface 26 against which the first cutting tool part 12 can be placed along the axis of rotation 20. The coupling interface 24 also comprises two centering surfaces 28a, 28b by means of which the first cutting tool part 12 can be centered on the second cutting tool part 16.

[0047] The centering surfaces 28a, 28b are configured as radial inner surfaces of two driver fingers 30a, 30b.

[0048] The driver fingers 30a, 30b also serve to introduce a torque, starting from the second cutting tool part 16, into the first cutting tool part 12, which of course carries the cutting edge 14.

[0049] For coupling the two cutting tool parts 12, 16, the coupling interface 24 also comprises a rotatably mounted coupling cam 32 (see in particular FIGS. 2 and 7).

[0050] In the present case, the coupling cam 32 is produced in one piece with a camshaft 34.

[0051] The composite consisting of the camshaft 34 and the coupling cam 32 is mounted in the second cutting tool part 16 such that it can rotate about an axis of rotation 36.

[0052] A tool engagement contour 37 is also provided at one end of the camshaft 34, so that the camshaft 34 can be rotated together with the coupling cam 32 by means of a tool.

[0053] As is evident in particular from the illustration of FIG. 2, the coupling cam 32 is mounted together with the camshaft 34 in an end portion of the second cutting tool part 16 which faces the first cutting tool part 12.

[0054] The coupling cam 32 is furthermore elliptical in a cross-section oriented substantially perpendicular to the axis of rotation 36 (see FIGS. 3 and 4).

[0055] The axis of rotation 36 of the coupling cam 32 extends substantially perpendicular to the axis of rotation 20 of the rotary cutting tool 10 (see FIGS. 3 to 5).

[0056] The coupling mechanism 22 also comprises an engagement surface 38, which is disposed in the region of a groove base 40 of a coupling groove 42.

[0057] The coupling groove 42 is configured on the first cutting tool part 12 and extends substantially diametrically with respect to the axis of rotation 20 (see FIGS. 3, 4 and 6).

[0058] The coupling groove 42 is furthermore open in the direction of the second cutting tool part 16.

[0059] The engagement surface 38 is configured as a circular cylinder jacket surface portion, the associated central axis 43 of which, on the one hand, extends perpendicular to the axis of rotation 20 of the rotary cutting tool 10 and, on the other hand, is aligned substantially parallel to the axis of rotation 36 of the coupling cam 32 (see FIGS. 3 and 4).

[0060] The engagement surface 38 also forms an undercut 44 which acts in the direction of the axis of rotation 20 of the rotary cutting tool 10.

[0061] The coupling groove 42 with the engagement surface 38 thus forms a coupling interface 46 of the first cutting tool part 12 for coupling with the second cutting tool part 16.

[0062] The coupling cam 32 can assume two specific positions when it interacts with the engagement surface 38.

[0063] In an assembly position, which can in particular be seen in FIG. 3, a largest diameter D.sub.max of the coupling cam 32 is oriented along the axis of rotation 20.

[0064] Consequently, the largest diameter D.sub.max of the coupling cam 32 is also oriented along a depth direction of the coupling groove 42.

[0065] The coupling cam 32 and the coupling groove are matched to one another such that, in this assembly position, the coupling cam 32 can be slid along the depth direction inside the coupling groove 42.

[0066] In other words, a groove width d is at least slightly larger than a smallest diameter D.sub.min of the coupling cam which is then oriented transverse to the axis of rotation 20 and transverse to the depth direction of the coupling groove 42.

[0067] Now, when the first cutting tool part 12 is aligned along the axis of rotation 20 relative to the second cutting tool part 16 such that it abuts the axial abutment surface 26, the coupling cam 32 is located in the region of the groove base 40 of the coupling groove 42. It can now be rotated about the axis of rotation 36 so that it assumes a coupling position in which it abuts the engagement surface 38 (see FIG. 4).

[0068] Since the largest diameter D.sub.max of the coupling cam 32 is now no longer oriented along the axis of rotation 20 but transversely to it, said coupling cam engages behind the undercut 44.

[0069] As a result, the two cutting tool parts 12, 16 are coupled to one another in a form-locking manner.

[0070] This form-locking coupling exists in particular along the axis of rotation 20 and in a direction in which the two cutting tool parts 12, 16 are separated from one another, i.e. removed from one another.