MILLING TOOL FOR MILLING WORKPIECES

Abstract

A milling tool for milling workpieces, having a shank which can be rotated about an axis of rotation and at least one milling portion arranged on the shank along the axis of rotation. The milling portion first and second cutters arranged on the circumference and extending substantially over the milling portion in the direction of the axis of rotation and next to one another and/or one behind another as viewed in the direction of rotation/circumferential direction. The first cutter is arranged at a first angle and the second cutter is arranged at a second angle with respect to the axis of rotation. The first angle is not equal to the second angle. A first chip receptacle for receiving a chip of the workpiece that has been cut off is arranged at least between the first and the second cutter.

Claims

1. A milling tool for milling workpieces, comprising a shank which can be rotated about an axis of rotation and at least one milling portion arranged on the shank along the axis of rotation, wherein the milling portion comprises at least a first cutter arranged on the circumference and a second cutter arranged on the circumference, wherein the first cutter and the second cutter extend substantially over the milling portion in the direction of the axis of rotation and are arranged next to one another and/or one behind another as viewed in the direction of rotation/circumferential direction, wherein the first cutter is arranged at a first angle (α) and the second cutter is arranged at a second angle (β) with respect to the axis of rotation, wherein at least one first chip receptacle for receiving a chip of the workpiece that has been cut off is arranged at least between the first and the second cutter, wherein the first angle (α) is not equal to the second angle (β).

2. The milling tool as claimed in claim 1, wherein with respect to the axis of rotation, the first angle is a positive angle and the second angle is a negative angle and the first cutter is in the form of a right-handed cutting helix and the second cutter is in the form of a left-handed cutting helix.

3. The milling tool as claimed in claim 1, wherein the magnitude of the first angle is equal to the magnitude of the second angle with respect to the axis of rotation.

4. The milling tool as claimed in claim 1, further comprising two first cutters and a second chip receptacle arranged between the two first cutters, and/or two second cutters and a third chip holder arranged between the two second cutters.

5. The milling tool as claimed in claim 4, further comprising at least a first milling segment and a second milling segment provided in the direction of rotation/circumferential direction, wherein the first milling segment has the first cutters and the second milling segment has the second cutters.

6. The milling tool as claimed in claim 5, further comprising at least one fourth chip receptacle arranged between the first milling segment and the second milling segment.

7. The milling tool as claimed in claim 6, wherein the first chip receptacle is designed as the second or third or fourth chip receptacle.

8. The milling tool as claimed in claim 6, further comprising at least a fifth chip receptacle provided transversely to the first cutter and/or second cutter, which interrupts the course of the corresponding cutter and/or constitutes a recess in the corresponding cutter.

9. The milling tool as claimed in claim 8, wherein with respect to the axis of rotation, the fifth chip receptacle is arranged at a third angle with the result that the fifth chip receptacle is aligned from an end region of the milling portion toward the shank as viewed counter to the direction of rotation.

10. The milling tool as claimed in claim 6, wherein with respect to the axis of rotation the fourth chip receptacle is arranged at a fourth angle or parallel to the axis of rotation.

11. The milling tool as claimed in claim 8, wherein at least the first cutter has a first cutting edge that is interrupted multiple times by the fifth chip receptacle so that the first cutting edge has multiple first edge portions.

12. The milling tool as claimed in claim 8, wherein at least the second cutter has a second cutting edge that is interrupted multiple times by the fifth chip receptacle so that the second cutting edge has multiple second edge portions.

13. The milling tool as claimed in claim 11, wherein the first cutter and/or first cutting edge and/or the first edge portions is/are in the form of a section of a helical line.

14. The use of a milling tool as claimed in claim 1 for milling workpieces made of at least partially fiber-containing materials.

15. The milling tool according to claim 2, wherein the first and second angles are acute angles.

16. The milling tool according to claim 9, wherein the third angle is an obtuse angle.

17. The milling tool as claimed in claim 12, wherein the second cutter and/or second cutting edge and/or second edge portions is/are in the form of a section of a helical line.

18. The use of a milling tool as claimed in claim 1 for milling workpieces made of carbon-fiber-containing or glass-fiber-containing plastics/composite materials.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] An exemplary embodiment of the present invention is illustrated in the drawing and explained in more detail below with reference to the figures.

[0029] FIG. 1 shows a schematic side view of a milling tool according to the present invention;

[0030] FIG. 2 is a schematic perspective view of the milling tool according to FIG. 1; and

[0031] FIG. 3 shows a schematic plan view of the milling tool according to FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

[0032] FIG. 1 schematically illustrates a milling tool 1 according to the present invention having a shank 2 that can be clamped into a machine tool and having a milling portion 3. The milling portion 3 comprises multiple main features or main cutters 4, i.e. what are known as “T1 main cutters”, each having multiple cutting edges/helices or cutting-edge portions which are interrupted (multiple times) by one or more so-called “T2” chip breaker flutes. The main cutter 4 is usually also referred to as what is termed a “T1” cutting flute or T1 cutting edge. These main cutters 4 or T1 cutting edges 4 are each formed by means of a helical depression/flute 5 which is arranged in front of the respective edge 4 in the direction of rotation.

[0033] In FIG. 1, it is made clear that, according to the present invention and with respect to the axis of rotation 6 or longitudinal axis 6 of the milling tool 1, a first cutter 4 with a first angle α (alpha, e.g. approx. 20°+/−20° and a second cutter 4 with a second angle β (beta, e.g. approx. 20°+/−20° are provided. Thus, here the first cutter 4 or first main cutter 4 forms a left-handed helix which is aligned at the angle α in relation to the axis of rotation 6, and the second cutter 4 or second main cutter 4 forms a right-handed helix which is aligned at the angle β in relation to the axis of rotation 6.

[0034] The first and the second cutter 4 or main cutter 4 are, however, both aligned/designed for a right-handed mode of operation of the milling tool. This is very particularly also made clear in FIG. 2 and primarily in FIG. 3. It can be seen here that the cutters 4 or cutting edges 4 are each aligned in a (right-handed) direction of rotation 7 in order to remove chips from the workpiece.

[0035] The chips, which are not illustrated in more detail, are advantageously transported away on the one hand respectively by means of the flute 5 or “T1” cutting flute. A chip breaker flute T2 or T2 flute is advantageously likewise in the form of a helix and aligned at an angle γ (gamma, e.g. approx. 97°+/−20°) in relation to the axis of rotation 6. Thus, the windings of the single T2 flute or its T2 recesses are right-handed or rise right-handed around the axis of rotation 6 at an angle of approx. 97°, as is depicted by way of example in FIG. 1.

[0036] By contrast, according to the present embodiment variant, advantageously provided here are four segments I to IV (cf. FIG. 3), in each of which multiple, here preferably in each case three main cutters 4 or main features/T1 flutes are provided. In the adjacent segments I-IV, first cutters 4 and second cutters 4 alternate, i.e. segments I to IV with right-handed and then with left-handed main cutters 4 or T1 main features/T1 helices respectively alternate in the direction of rotation 7 or on the circumference.

[0037] As is made clear in the figures, provided between the segments I to IV is a respective recess 8 or longitudinal flute 8, which thereby delimit or spatially define the segments I to IV, as it were. The longitudinal groove 8 depicted is aligned substantially parallel to the axis of rotation 6 or longitudinal axis 6, with the result that the segments I to IV extend in the form of straight cylinder quarters along the axis of rotation 6.

[0038] As an alternative to this, the longitudinal flutes 8 or recesses 8 may also be in the form of a helix, for example, a right-handed helix with an angle delta which advantageously corresponds to the angle of the right-handed cutter 4 or T1 main cutter. In that case, this angle delta could have, for example, δ=approx. 20°+/−20° and would correspond to the angle β in FIG. 1, wherein however the left-handed helix could optionally be furthermore formed at the angle α=approx. 20°.

[0039] By contrast, use has been made to date exclusively of milling tools in which the main cutters or T1 main features are implemented so as to be wound around the axis of rotation in the same direction or in the same way and to have the same angles. The exemplary embodiment illustrated, however, has different angles α and 3 which, although they have a magnitude, i.e. in the illustrated variant of e.g. approx. 20°+/−20°, are unequal or different in terms of the mathematical sign or in terms of the alignment with respect to the axis of rotation 6. In this way, protruding fiber ends or burrs are effectively avoided or at least minimized in an advantageous manner, specifically in the case of fiber-containing materials.

[0040] As is made clear in turn primarily in FIG. 3, the third chip flute 8 is advantageously provided between two segments I-IV in each case. This allows the chips to be transported away, as it were. Essentially, during the manufacture of the milling tool 1, by virtue of this flute 8, in particular, the main cutters 4 or T1 main features, disadvantageous protrusions or edges in the transition region of the first and second cutters 4, which run in opposite directions, become advantageously avoidable. As already set out above, in the present exemplary embodiment these four third chip flutes 8 or longitudinal flutes 8 are aligned parallel to the axis of rotation 6 and thus at the angle δ=0° (delta) (cf. FIG. 1).

[0041] Cutters or surfaces, for example, at the angle ε (epsilon, e.g. approx. 20°+/−20°) are provided on the end face of the milling tool 1 or the milling portion 3, such that end-face milling can also be implemented, e.g. for the purpose of what is known as “dipping” into a workpiece (cf. FIG. 1). This end or this tip of the tool may, however, also be shaped/designed in almost any desired way, i.e. may be designed not only as depicted with a V-shaped cross section, but also with a straight/flat or (semi−) circular or rounded cross section or else with a protective bevel or the like.

[0042] In addition, it can be seen in FIG. 3 that the main cutters 4 or cutting flutes 5 are each arranged at an angle (kappa, e.g. approx. 8°+/−5°) with respect to a longitudinal center plane 9, in order to generate an advantageous rake angle.

[0043] The milling tool 1 according to the invention which is illustrated in the figures is a geometrically relatively complex tool which here advantageously cuts in a right-handed manner or has the main cutters 4 aligned in a right-handed manner, but as what are termed T1 main features comprises not only right-handed main cutters 4 or main cutters with a right-handed helix, but also left-handed main cutters 4 or main cutters with a left-handed helix, which are arranged separately in the circumferential direction or separately in defined segments I to IV. This has the advantageous effect that, during the processing of fiber-containing material, fibers or fiber ends are respectively deflected from a segment I-IV in the one direction and deflected from the following, adjacent segment I-IV in the other, opposite direction and thus are severed in an advantageous manner. This prevents or reduces burr formation and/or protruding fiber ends in a particular way. This makes it possible to omit complex or more cost-intensive reworking in many usage situations.

LIST OF REFERENCE SIGNS

[0044] 1 Milling tool [0045] 2 Shank [0046] 3 Milling portion [0047] 4 Main cutter [0048] 5 Flute [0049] 6 Axis of rotation/Longitudinal axis [0050] 7 Direction of rotation [0051] 8 Longitudinal flute [0052] α Angle [0053] β Angle [0054] γ Angle [0055] δ Angle [0056] ε Angle [0057] Angle [0058] T1 Main feature [0059] T2 Secondary feature