Cutting tool and method for producing a cutting tool

Abstract

A cutting tool for machining workpieces is disclosed, which comprises a shank portion and a cutting portion, wherein a coolant channel extends along a longitudinal axis from a free end of the shank portion through the cutting tool, which has a peripheral wall and an end wall, wherein the coolant channel has one or more outlet openings in the end wall, through which coolant can exit the cutting tool. Also disclosed is a method for producing a cutting tool.

Claims

1. A cutting tool for machining workpieces, comprising a shank portion and a cutting portion, wherein a coolant channel extends along a longitudinal axis from a free end of the shank portion through the cutting tool, which has a peripheral wall and an end wall, wherein the coolant channel has one or more outlet openings in the end wall, through which coolant can exit the cutting tool.

2. The cutting tool according to claim 1, wherein the coolant channel extends in a straight line exclusively along a longitudinal axis of the cutting tool.

3. The cutting tool according to claim 1, wherein the coolant channel has a constant cross-section.

4. The cutting tool according to claim 1, wherein the coolant channel is stepped, wherein at least one additional outlet opening is formed on the stepped portion.

5. The cutting tool according to claim 1, wherein, on the end wall of the coolant channel, there is an elevation which projects into the coolant channel.

6. The cutting tool according to claim 1, wherein, at least in sections, a diameter of the coolant channel is between 60% and 95% of a nominal diameter of the cutting tool.

7. The cutting tool according to claim 1, wherein notches or depressions are configured in an end face of the cutting portion, which intersect with the coolant channel.

8. The cutting tool according to claim 1, wherein flutes extend along the cutting portion, which intersect with the coolant channel.

9. The cutting tool according to claim 1, wherein the coolant channel ends at a distance of less than 10 mm from a front end of the cutting portion.

10. A method for producing a cutting tool for machining workpieces comprising: providing a blank having a shank portion, a cutting portion, and a coolant channel, which has a peripheral wall and an end wall, forming notches or depressions on an end face of the cutting portion and thereby creating outlet openings in the end wall of the coolant channel.

11. The method according to claim 10, wherein the blank is sintered and the notches or depressions are formed after sintering the blank, for example by means of milling or grinding.

12. A method for producing a cutting tool for machining workpieces comprising: providing a blank having a shank portion, a cutting portion, and a coolant channel, which has a peripheral wall and an end wall, forming flutes along the cutting portion and thereby creating outlet openings in the end wall of the coolant channel.

13. The method according to claim 12, characterized in that the coolant channel is stepped and, when the flutes are formed, outlet openings are created in both the end wall of the coolant channel and on the stepped portion of the coolant channel.

14. The method according to claim 12, wherein the blank is produced by means of injection molding.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Further advantages and features of the invention result from the following description and from the accompanying drawings, to which reference is made. The drawings show:

[0042] FIG. 1 a cutting tool according to the invention in a perspective view,

[0043] FIG. 2 a longitudinal section through the cutting tool of FIG. 1,

[0044] FIG. 3 a further section through the cutting tool of FIG. 1,

[0045] FIG. 4 a plan view onto an end face of the cutting tool of FIG. 1,

[0046] FIG. 5 a side view of the cutting tool of FIG. 1,

[0047] FIG. 6 a longitudinal section through a cutting tool according to a further embodiment according to the invention,

[0048] FIG. 7 a cutting tool according to the invention according to a further embodiment,

[0049] FIG. 8 a detail view of the cutting tool of FIG. 7 in the region of the cutting tip,

[0050] FIG. 9 a cutting tool according to the invention according to a further embodiment,

[0051] FIG. 10 a cutting tool according to the invention according to a further embodiment in a side view,

[0052] FIG. 11 the cutting tool of FIG. 10 in a plan view, and

[0053] FIG. 12 the cutting tool of FIG. 10 in a rear view.

DETAILED DESCRIPTION

[0054] FIG. 1 shows a cutting tool 10 for machining a workpiece in a perspective view. The cutting tool 10 shown in FIG. 1 is in particular a reamer. The cutting tool 10 has a cutting portion 12 and a shank portion 14, wherein the shank portion 14 has been shortened in the drawing.

[0055] The cutting tool 10 comprises a plurality of outlet openings 16, through which coolant can exit the cutting tool 10.

[0056] The outlet openings 16 open into an end face 18 of the cutting tool 10. The end face 18 refers to the surface that is visible in a plan view onto a tip of the cutting portion 12. Coolant exiting from the outlet openings 16 is thus available at the end face 18 immediately after exiting the cutting tool 10.

[0057] A plurality of notches 20 or depressions are also formed at one end of the cutting portion 12. The notches 20 extend from a front end 22 of the cutting portion 12, at a 45° angle to the longitudinal axis of the cutting tool 10.

[0058] The notches 20 in particular form a part of the end face 18.

[0059] The outlet openings 16 are disposed in the notches 20.

[0060] Starting from the end face 18, a plurality of guide surfaces 24 extend along the cutting portion 12.

[0061] A cut end 26 is further provided at one end of the cutting portion 12, which facilitates the insertion of the cutting tool 10 into a predrilled hole, for example.

[0062] FIG. 2 shows a longitudinal section through the cutting tool 10 of FIG. 1. FIG. 3 shows a supplementary perspective sectional view through the cutting tool 10.

[0063] In the sectional views, it can be seen that a coolant channel 28 extends through the cutting tool 10. More precisely, the coolant channel 28 extends along a longitudinal axis L from a free end of the shank portion 14 through the cutting tool 10.

[0064] The coolant channel 28 extends in a straight line exclusively along the longitudinal axis L of the cutting tool 10. This means that the coolant channel 28 is free of branches and the coolant channel 28 does not curve and/or bend sharply.

[0065] The coolant channel 28 has a constant cross-section, in particular a round cross-section (see also FIG. 4). However, other cross-sectional shapes are conceivable as well.

[0066] A diameter of the coolant channel 28 can be between 60% and 95% of a nominal diameter of the cutting tool 10. In the depicted design example, the diameter of the coolant channel 28 is approximately 75% of the nominal diameter of the cutting tool 10.

[0067] The coolant channel 28 has a peripheral wall 30 and an end wall 32. The outlet openings 16 are formed in the end wall 32 of the coolant channel 28.

[0068] As can be seen in FIG. 2, the outlet openings 16 can extend a short distance into the peripheral wall 30. However, there are no outlet openings 16 that are not formed at least in sections in the end wall 32. In other words, the outlet openings 16 are disposed in the region of an edge between the peripheral wall 30 and the end wall 32, wherein the outlet openings 16 extend beyond the edge.

[0069] The notches 20 intersect with the coolant channel 28, as can be seen in FIG. 2. The outlet openings 16 are thus formed by the notches 20. The size of the outlet openings 16 depends on the size of the intersection of the notches 20 with the coolant channel 28.

[0070] In the shown design example, the notches 20 extend at an approximately 45° angle to the longitudinal axis L of the cutting tool 10, wherein the notches 20 are slightly curved when viewed in section.

[0071] A distance d of the end wall 32 to a front end of the cutting portion 12 is less than 10 mm, for example, in particular less than 2 mm.

[0072] FIG. 4 shows a plan view onto the cutting portion 12. FIG. 4 in particular shows the end face 18 of the cutting tool 10. The cutting tool 10 is transparent in the drawing, so that a position of the coolant channel 28 in the cutting tool 10 and an outline of the coolant channel 28 can be seen.

[0073] FIGS. 2 and 4 show that, both in side view and in plan view, the outlet openings 16 have approximately the shape of a divided oval. Therefore, viewed as a whole, the outlet openings 16 have an approximately oval shape.

[0074] FIG. 5 shows a side view of the cutting tool 10. FIG. 5 shows that the cutting portion 12 tapers toward the end face 18.

[0075] FIG. 6 shows a longitudinal section through a cutting tool 10 according to a further embodiment. The embodiment depicted in FIG. 6 differs from the embodiment described with reference to FIGS. 1 to 5 in that an elevation 34 is disposed on the end wall 32 of the coolant channel 28, which projects into the coolant channel 28. The elevation 34 is in particular disposed centrally in the coolant channel 28, i.e. a central axis of the elevation 34 is superimposed on the longitudinal axis L of the cutting tool 10.

[0076] The elevation 34 ensures improved stability of the cutting tool 10 in the region of the end wall 32.

[0077] The elevation 34 moreover forms an annular channel section 38 of the coolant channel 28, which ensures that the coolant flows specifically to the outlet openings 16.

[0078] The elevation 34 also provides a large enough thickness of material in the region of the end face 18 of the cutting tool 10 to create a centering bore 40 in the end face 18. The centering bore 40 facilitates the clamping of the cutting tool 10, for example for the purpose of reconditioning the cutting tool 10.

[0079] In the design example shown, the elevation 34 is cylindrical.

[0080] The elevation 34 can optionally have a rounding or a chamfer on its free peripheral edge 36. This has an advantageous effect on the flow behavior of the coolant in the coolant channel 28.

[0081] FIG. 7 shows a further embodiment of the cutting tool 10. The cutting tool 10 shown in FIG. 7 is a twist drill, along the cutting portion 12 of which a plurality of flutes 42 extend.

[0082] The cutting tool 10 according to FIG. 7 likewise comprises a coolant channel 28.

[0083] FIG. 7 shows an inlet opening 44 of the coolant channel 28. As in the previously described embodiments, the end wall 32 of the coolant channel 28 is disposed near the front end of the cutting portion 12, for example at a distance of less than 5 mm, in particular at a distance of less than 2 mm to a cutting edge 48 of the cutting tool 10.

[0084] As can be seen in FIG. 8, which shows a detail view of the cutting tool 10 of FIG. 7 in the region of a cutting tip of the cutting tool 10, the outlet openings 16 are disposed inside the flutes 42.

[0085] By contrast to the previous embodiments, the coolant channel 28 has a smaller diameter in the region of the cutting portion 12, for example a diameter of less than 40% of the nominal diameter. Otherwise, the flutes 42 would open excessively large outlet openings 16 in the cutting tool 10. This can be achieved, for example, by the coolant channel 28 being stepped or having a smaller cross-section along its entire length.

[0086] In the embodiment shown in FIGS. 7 and 8, in which outlet openings 16 are provided only near the cutting tip, the stepped portion is preferably located in the region of the shank portion 14. The stepped portion then serves only to facilitate the removal of the cutting tool 10 from the mold.

[0087] FIG. 9 shows a further embodiment of a cutting tool 10. The cutting tool 10 depicted in FIG. 9 is similar to the cutting tool 10 shown in FIGS. 7 and 8 and is likewise a twist drill.

[0088] The cutting tool 10 depicted in FIG. 9 also has a stepped coolant channel 28. For better illustration, the coolant channel 28 is shown as a dashed line in FIG. 9.

[0089] The stepped portion 46 makes it possible to easily create a plurality of outlet openings 16 which are spaced apart in longitudinal direction. At least one outlet opening 16 is in particular disposed on the stepped portion 46. In this case, the stepped portion 46 is disposed in the region of the cutting portion 12.

[0090] A method for producing a cutting tool 10 according to FIGS. 1 to 6 and a method for producing a cutting tool 10 according to FIGS. 7 to 9 are described in the following.

[0091] In both cases, a blank is first provided, which has a shank portion 14, a cutting portion 12 and a coolant channel 28, wherein the coolant channel has a peripheral wall 30 and an end wall 32.

[0092] The blank is produced by injection molding, for example. The blank is then sintered.

[0093] Preferably after sintering, notches 20 are formed on an end face of the cutting portion 12, for example by means of milling or grinding. As a result, the outlet openings 16 are created in the end wall 32 of the coolant channel 28.

[0094] Instead of notches 20, flutes 42 can also be created along the cutting portion 12. This likewise creates outlet openings 16 in the end wall 32 of the coolant channel 28.

[0095] When the coolant channel 28 is stepped, outlet openings 16 can be created in both the end wall 32 of the coolant channel 28 and on the stepped portion 46 of the coolant channel 28 when the flutes 42 are formed.

[0096] FIGS. 10 to 12 show a further embodiment of a cutting tool 10, wherein FIG. 10 shows the cutting tool 10 in a side view, FIG. 11 shows the cutting tool 10 in a plan view onto the end face 18, and FIG. 12 shows the cutting tool 10 in a rear view.

[0097] In FIG. 10, it can be seen that the cutting tool 10 also has a shank portion 14 and a cutting portion 12.

[0098] A coolant channel 28 again extends along a longitudinal axis from a free end of the shank portion 14 through the cutting tool 10, which has two outlet openings 16 in the end wall through which coolant can exit the cutting tool 10.

[0099] The cutting tool 10 shown in FIGS. 10 to 12 is a drill tip, which can be used as a wear part in a twist drill, for example.

[0100] The cutting tool 10 according to FIGS. 10 to 12 is fundamentally the same as the cutting tool shown in FIGS. 7 and 8, but is much shorter in comparison.