MACHINING TOOL

Abstract

A machining tool for machining fiber-reinforced materials, which comprises a plurality of flutes which separate lands from each other in the circumferential direction, wherein at least one land includes a plurality of cutting edges on its circumferential side, the cutting edges extending at a helix angle (a1-an, b1-bn, c1-cn, d1-dn) having an absolute value >25 with respect to the longitudinal axis of the machining tool, wherein at least two cutting edges on the at least one land have different helix angles (a1-an, b1-bn, c1-cn, d1-dn).

Claims

1. A machining tool (2, 2.2, 2.3) for machining fiber-reinforced materials, which comprises a plurality of flutes (3, 4) which separate lands (5, 6, 7, 20, 5.3, 6.3) from each other in the circumferential direction, wherein at least one land (5, 6, 7, 20, 5.3, 6.3) includes a plurality of cutting edges (10, 21, 30, 31, 39) on its circumferential side, the cutting edges extending at a helix angle (a1-an, b1-bn, c1-cn, d1-dn) having an absolute value >25 with respect to the longitudinal axis (15) of the machining tool (2, 2.2, 2.3), wherein at least two cutting edges (10, 21, 30, 31, 39) on the at least one land (5, 6, 7, 20, 5.3, 6.3) have different helix angles (a1-an, b1-bn, c1-cn, d1-dn).

2. The machining tool as claimed in claim 1, wherein all cutting edges (10, 21, 30, 31, 39) of a land (5, 6, 7, 20, 5.3, 6.3) have different helix angles (a1-an, b1-bn, c1-cn, d1-dn).

3. The machining tool as claimed in claim 1, wherein the cutting edges (10, 21, 30, 31, 39) of a first land (5, 6, 7, 20, 5.3, 6.3) have a positive helix angle (a1-an) and the cutting edges of a land following in the circumferential direction have a negative helix angle (b1-bn), or vice versa.

4. The machining tool as claimed in claim 1, wherein, on one land (5, 6, 7, 20, 5.3, 6.3) a first group (b, d) of cutting edges is provided, each of which has a helix angle (b1-bn, d1-dn) having a smaller absolute value than a first predefined helix angle, and a second group (a, c) of cutting edges is provided, each of which has a helix angle (a1-an, c1-cn) having a greater absolute value than a second predefined helix angle, wherein the absolute value of the second predefined helix angle is greater than or equal to the first predefined helix angle.

5. The machining tool as claimed in claim 4, wherein all cutting edges (13, 14) of a group (a, b, c, d) have different helix angles (a1-an, b1-bn, c1-cn, d1-dn).

6. The machining tool as claimed in one of claim 4, wherein cutting edges of the first and the second groups (a, b, c, d) are situated in alternation in the longitudinal direction of the machining tool.

7. The machining tool as claimed in claim 4, wherein the difference of the first and the second predefined helix angles is greater than the difference of any two helix angles (a1-an, b1-bn, c1-cn, d1-dn) within one group (a, b, c, d).

8. The machining tool as claimed in claim 1, wherein cutting edges (30, 31) having positive and negative helix angles are situated on one land.

9. The machining tool as claimed in claim 8, wherein at least one cutting edge (30, 31) having a positive helix angle and a cutting edge having a negative helix angle intersect.

10. The machining tool as claimed in claim 1, wherein assigned to each cutting edge (40) is a chip space (42) and a flank (43).

11. The machining tool as claimed in claim 1, wherein the cutting lip of at least one cutting edge is formed with a circularly ground land.

12. The machining tool as claimed in claim 1, wherein one or multiple cutting edges (39) is/are provided between two lands (5.3, 6.3) spaced apart by a flute, the cutting edges having an angle with respect to the longitudinal axis of the machining tool in the range 15 to +15, preferably in the range 10 to +10.

Description

[0021] In the drawing:

[0022] FIG. 1 shows a perspective representation of the cutting section of a machining tool;

[0023] FIG. 2 shows one implementation of cutting lips of cutting edges;

[0024] FIG. 3 shows a representation of the cutting section of a machining tool for indicating different force vectors;

[0025] FIG. 4 shows yet another representation of implementations of cutting lips for indicating different groups of cutting lips having different helix angles;

[0026] FIG. 5 shows the cutting section of a machining tool comprising cutting edges having a positive helix angle and a negative helix angle;

[0027] FIG. 6 shows a perspective representation of a cutting section of a machining tool comprising a cutting edge between the lands of the machining tool; and

[0028] FIG. 7 shows cutting edges including assigned cutting lips, chip space, and flank.

[0029] FIG. 1 shows the cutting section 1.1 of a machining tool 2. Adjoining the cutting section 1.1 at the top is yet another section 1.2, with the aid of which the machining tool 2 can be clamped.

[0030] The machining tool 2 is designed substantially cylindrically. The machining tool comprises flutes 3, 4 which separate lands 5, 6, 7 from each other. By way of the land 5, it is shown that the lands 5 to 7 comprise cutting edges 10 on the circumference. The cutting edges 10 are spaced apart from each other by grooves 11.

[0031] FIG. 2 shows one implementation of cutting lips 13, 14 of cutting edges, such as the cutting edge 10. The cutting lips 14 have a positive helix angle a1, a2, an. This means, the angles a1, a2, an with respect to the longitudinal axis 15 of the machining tool 2 are positive. All cutting edges, including their assigned cutting lips 14, have different helix angles a1, a2, an. This means, a1a2an.

[0032] The cutting edges including the cutting lips 13 therefore have a negative helix angle b1, b2, bn. In this case, it also applies that b1b2bn. This means, there are no cutting edges whose cutting lips extend in parallel. The cutting lips 13 having the negative helix angle b1, b2, bn can be situated on a first land and the cutting edges including assigned cutting lips 14 can be situated on an adjacent land. Therefore, lands 5 to 7 spaced apart by a flute 3, 4 are provided with cutting edges having helix angles having different signs.

[0033] FIG. 3 shows a land 20 which comprises cutting edges 21 having negative helix angles b1, b2, bn. This yields different directions of the force vectors 22, 23, 24, 25 from cutting edge to cutting edge. The low-noise operation is improved as a result.

[0034] Yet another embodiment is shown in FIG. 4, wherein implementations of cutting lips of cutting edges are also represented here. A first land comprises cutting edges having a negative helix angle c1 to cn and d1 to dn. The following land has positive helix angles a1 to an and b1 to bn. Cutting edges from two groups are situated in alternation on each land. All helix angles are different (a1a2an; b1b2bn; c1c2cn; d1d2dn) within each group a, b, c, d. The two groups per land have a higher difference between the helix angles than the difference of the helix angles within one group. This constellation yields a scattering in the direction of the force vectors.

[0035] In particular, it is provided in this case that the helix angles c1, c2, cn have greater absolute values than a predefined first helix angle and the helix angles d1, d2, dn have lower absolute values than a predefined second helix angle. The predefined helix angles can be the same or different. When different predefined helix angles are provided, the predefined helix angle which is less than c1, c2, cn is greater than the predefined helix angle which is greater than the helix angles d1, d2, dn.

[0036] The same applies for the helix angles a1, a2, an and b1, b2, bn.

[0037] FIG. 5 shows yet another embodiment of a machining tool 2.2, in which cutting edges 30 having a positive helix angle and cutting edges 31 having a negative helix angle are situated on one land.

[0038] All helix angles have an absolute value greater than 30. Cutting edges 30, 31 having a positive helix angle and a negative helix angle can intersect.

[0039] In the embodiment of a machining tool 2.3 according to FIG. 6, yet another cutting edge 39 is situated between the land 5.3 and the land 6.3, which has an angle with respect to the longitudinal axis of the machining tool 2.3 in the range between 10 and +10. In the exemplary embodiment shown, the cutting edge has an angle, in particular, of 0 with respect to the longitudinal axis of the machining tool 2.3.

[0040] As shown in FIG. 7, assigned to each cutting edge 40 is a cutting lip 41, a chip space 42, and a flank 43.