Method for manufacturing a cutting tool

Abstract

A method for manufacturing a cutting tool is proposed, wherein the cutting tool has a tool body 1 provided with a hard coating 2, and the hard coating 2 is adhered onto the tool body 1 at least in regions of cutting edges 10, 14, 14a, 43, relief surfaces 5, 25, 45, and rake surfaces 6, 26, 46. In that case, first, on the surface of the tool body 1 of the cutting tool, the hard coating 2 is adhered onto a workpiece in regions of cutting edges 3, 23, 43, the relief surfaces 5, 25, 45 adjacent to the cutting edges 3, 23, 43, and the rake surfaces 6, 26, 46 adjacent to the cutting edges 3, 23, 43. Subsequently, for the honing of the cutting edges, the hard coating on the relief surface is partially removed by laser machining such that 1° ≤ δ ≤ 70° holds with respect to the angle δ between a first geometric plane 16, 36 on which the surface 9 of the tool body 1 extending under the hard coating 2 of the relief surfaces 5, 25, 45 extends, and a second geometric plane 18, 38 on which the surface 8, 28 of the hard coating 2 defined by the honed cutting edges 10, 14, 43 in the region of the relief surfaces 5, 25, 45 after removal extends.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a cutting tool having at least one cutting edge, wherein the cutting tool has a tool body, and the tool body is provided with a hard coating.

Background Art

[0002] Cutting tools include cutting tools (Zerspanungswerkzeuge) for cutting-based (spanabhebende) manufacturing methods and tools for splitting (Zerteilen). These tools usually have a shank and a cutting part. In that case, at least one end part of the shank is used for holding the cutting tool, for example, within a machine connection (Maschinenschnittstelle) in a machining tool. In this shank, the cutting part is arranged. This cutting part has at least one cutting edge, by which the cutting tool comes into interaction with the workpiece to be machined and, in that case, removes material from the workpiece. For example, milling cutters, drills, reamers, bits, scrapers, planers, and saws are regarded as part of this type of cutting tool. In that case, the cutting tool is a solid tool, and this solid tool is made of a consistent single material. Alternatively, it is also possible for the cutting part to have an insert with a cutting edge, where the insert is made of a material different from the shank. Cutting tools are under the influence of significant mechanical and thermal loads based on the forces acting on these cutting tools and the temperatures generated at the locations where these cutting tools are used. Mechanical friction, oxidation, and wear, as well as diffusion and scaling, especially at high machining speeds, are regarded as part of these. This induces wear of the cutting tool within the region of the cutting edge.

[0003] In order to improve the wear resistance of a cutting tool and increase its service life, the cutting tool is provided with a hard coating in the region of the cutting edge. This hard coating is applied onto the tool body. For example, a diamond coating, an amorphous carbon coating called Diamond like Carbon, DLC (Diamond-Like Carbon) in English, and a titanium coating are regarded as part of this type of hard coating. These are applied onto the tool body, for example, by chemical vapor deposition, Chemical Vapor Deposition, CVD in English. After the deposition of the hard coating, the coated cutting edge has a rounded tip portion. In order for the cutting edge to have the desired edge radius, this rounded tip portion subsequently needs to be ground. For this purpose, a part of the hard coating is removed in the region of the cutting edge. The grinding of the cutting edge by removing a part of the hard material on the surface of the cutting tool can be carried out, for example, by a laser processing device. This material removal is also referred to as laser ablation or laser evaporation. The material can be removed, for example, in a planar manner, in a layer state. In that case, the laser beam is basically oriented perpendicular to the plane in which a part of the hard coating is removed. Here, the flank face or the rake face is being dealt with. A method of this type is known, for example, from Patent Document 1 and Patent Document 2. Furthermore, there is a possibility of separating a part of the hard coating by a continuous or pulsed laser beam, where this laser beam is basically oriented parallel to the surface to be produced. A method of this kind is known, for example, from Patent Document 3. In that case, it is possible that the laser beam is oriented onto a cutting tool to be machined such that it starts within the area of the cutting edge where material removal is to be produced, as shown in FIG. 1 of Patent Document 3. This is also referred to as material removal from the front. Alternatively, as shown in FIG. 3 of Patent Document 3, material removal can also start on the flank of the cutting tool on the side opposite to the cutting edge to be produced. This is also referred to as material removal from the rear. The parameters of the laser radiation need to be adapted to the material to be processed and to the desired machining. Material removal can take place on the flank face, the rake face, or both.

[0004] The honing of the coated cutting edge is usually carried out such that the wedge angle of the uncoated tool body's cutting edge wedge, which is usually formed by the flank face and the rake face, matches the wedge angle of the coated and subsequently honed cutting edge wedge. However, this procedure has the drawback that, during the orientation of the laser beam parallel to the surface to be produced and during material removal from the rear, the laser beam can be deflected in an undesired way on the secondary flank face or on other surfaces of the cutting tool that do not correspond to either the flank face or the rake face. This kind of deflection of the laser beam can induce that the honing to be achieved on the cutting edge cannot be obtained in the laser machining.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] The underlying problem of the present invention is to provide a method for manufacturing a hard-coated cutting tool, in which a given edge radius of a coated cutting edge is obtained in a reliable manner even when a part of the hard coating is removed by a laser beam for honing the coated cutting edge, wherein the laser beam is not oriented perpendicular to the surface to be produced of the cutting tool, and material removal can also be performed from the rear.

Means for Solving the Problems

[0007] This problem is solved by a method for manufacturing a cutting tool having the features of claim 1. This method is such that, after partial material removal, the surface of the hard coating in the flank face region is not parallel to the surface of the tool body located beneath the surface of this hard coating, but rather, a first geometric plane in which the surface of the tool body located beneath the hard coating of the flank face extends, and a second geometric plane in which the surface of the hard coating defined by the honed cutting edge in the flank face region after removal extends, form an angle δ, and with respect to this angle, 1° ≤ δ ≤ 70° holds, which is characterized thereby. In that case, the surface of the tool body located below the coating on the flank face ends at the uncoated cutting edge portion, whereas it is considered that the geometric plane in which the surface of the tool body extends in its geometric plane extends infinitely far. The surface of the hard coating in the region of the flank face after partial material removal ends at the ground cutting edge portion, whereas a second geometric plane extends infinitely far. The first geometric plane and the second geometric plane intersect along a geometric straight line. This geometric straight line - coincides with the uncoated cutting edge portion of the tool body, or - coincides with the ground cutting edge portion of the cutting tool, or - extends outside the tool body and inside the hard coating on the rake face, or - extends outside the cutting tool.

Advantages of the Invention

[0008] The surface of the hard coating in the region of the flank face is preferably inclined such that after the end of material removal, the coating thickness of the hard coating on the flank face increases with increasing distance from this cutting edge starting from the cutting edge portion. When a hard coating having a uniform coating thickness is deposited on the cutting edge portion, the flank face, and the rake face, some material removal needs to be performed only in the immediate vicinity of the cutting edge portion during subsequent regrinding of the cutting edge portion. The amount of material to be removed from the hard coating decreases with increasing distance from the cutting edge portion. As a result, a cutting edge portion having a predetermined edge radius is generated, and at the same time, more material of the hard coating remains in the cutting tool. Since less material needs to be removed, the material removal is performed in a shorter time.

[0009] The cutting tool can be elongate and extend along a geometric longitudinal axis. For example, a milling cutter or a drill is considered to be part of this cutting tool. At least one cutting edge can be the main cutting edge or the secondary cutting edge. This cutting edge can be located on the end face side of the elongate cutting tool or can extend along the shaft within the region of the cutting groove.

[0010] The removal of the hard coating is carried out by laser machining. For this purpose, the laser beam of the laser machining machine is oriented at a predetermined angle relative to the surface of the hard coating at the flank face in order to partially remove the hard coating. In that case, the angle at which the laser beam is oriented relative to the surface of the cutting tool coated by this geometric beam axis of the laser beam depends on the angle δ, which is formed by the first geometric plane and the second geometric plane after the end of the material removal. Advantageously, the laser beam is oriented such that the geometric beam axis extends parallel or tangentially to the surface to be produced at the flank face. Since the laser beam is usually focused on the surface of the cutting tool, the opening angle of the laser beam is advantageously taken into account when orienting this laser beam. If the hard coating has a uniform coating thickness after the coating is applied in the region of the flank face, the laser beam can be oriented at an angle δ relative to the surface to be produced at the start of the material removal by this geometric beam axis of the laser beam. When the opening angle of the focused laser beam is taken into account, this angle corresponds to the sum of half the opening angle and the angle δ. The removal of the hard coating can, in that case, in particular, be carried out from the rear. This means that the removal starts within the flank face portion on the side opposite the sharp cutting edge to be produced. By this, an undesired deflection of the laser beam is avoided. Furthermore, it is ensured that the positions where the laser beam irradiates the cutting tool are all removed during the entire material removal. The surface produced on the flank face is thus smooth. This produced surface has a good surface quality. A ground cutting edge with a pre-given edge radius is produced in the desired quality.

[0011] According to yet another advantageous embodiment of the invention, on the tool body, the hard coating is deposited with a coating thickness between 2 μm and 40 μm.

[0012] According to yet another advantageous embodiment of the invention, the removal of the hard coating is carried out such that 2° ≤ δ ≤ 10°, particularly advantageously 3° ≤ δ ≤ 6° holds with respect to the angle δ. This angle δ typically depends on the coating thickness of the hard coating on the flank face, the material of this hard coating, and the wedge angle of the cutting edge wedge.

[0013] According to yet another advantageous embodiment of the invention, the removal of the hard coating is carried out such that 30° ≤ δ ≤ 70° holds with respect to the angle δ. A region of this manner with respect to the angle δ is advantageous, for example, when a first geometric plane and a second geometric plane intersect along a geometric straight line, and this straight line coincides with the uncoated cutting edge of the tool body. The uncoated cutting edge is thereby exposed. By this, mechanical or thermal stresses between the tool body and the hard coating are avoided.

[0014] According to yet another advantageous embodiment of the present invention, during the partial removal of the hard coating, the thickness of the hard coating on the flank face is such that the thickness of the hard coating increases with increasing distance from the ground cutting edge, starting from the ground cutting edge. Reduced.

[0015] According to yet another advantageous embodiment of the present invention, the first geometric plane and the second geometric plane intersect at the uncoated cutting edge. In this case, the hard coating is removed from the tool body within the region of the uncoated cutting edge. This can avoid mechanical or thermal stresses between the tool body and the hard coating.

[0016] According to yet another advantageous embodiment of the present invention, during the laser processing, the laser beam is defined by the geometric beam axis of this laser beam. The laser beam is oriented so as to form the angle δ with the first geometric plane. The beam axis of the laser beam extends parallel or tangentially to the second geometric plane in this case. The geometric beam axis is, in that case, a straight line in the mathematical sense, which extends infinitely far and, accordingly, extends through the hard coating.

[0017] According to yet another advantageous embodiment of the present invention, during the laser processing, the laser beam is defined by the beam axis of this laser beam. The laser beam is oriented so as to form the angle α with the second geometric plane, such that 1° ≤ α ≤ 10° holds for this angle. In that case, it is possible that the laser beam is focused on the surface of the workpiece, and thus, the fact that it has an opening angle is taken into account. Advantageously, the angle α corresponds to half of the opening angle of the laser beam.

[0018] According to yet another advantageous embodiment of the invention, the material removal of the hard coating on the flank face of the hard coating starts within a portion of the flank face spaced from the cutting edge and ends on the rake face. In this case, the material removal is performed from the rear. According to yet another advantageous embodiment of the invention, the cutting edge provided with the hard coating is ground such that 0° ≤ ε ≤ 70° holds with respect to the angle ε between a third geometric plane in which the surface of the tool body located below the hard coating on the rake face extends and a fourth geometric plane in which the surface of the hard coating defined by the ground cutting edge in the region of the rake face after the partial material removal extends.

[0019] According to yet another advantageous embodiment of the invention, the cutting edge provided with the hard coating is, by additional, partial removal of the hard coating within the region of the rake face, ground such that 0° ≤ ε ≤ 70° holds with respect to the angle ε between a third geometric plane in which the surface of the tool body located below the hard coating on the rake face extends and a fourth geometric plane in which the surface of the hard coating defined by the ground cutting edge in the region of the rake face after the partial material removal extends. In that case, it is possible for the angle δ to coincide with the angle ε in terms of magnitude or to be different from this angle ε. In this case, for the post-grinding of the cutting edge after the deposition of the hard coating, not only the coating thickness of the hard coating on the flank face is reduced, but also on the rake face. In that case, the material removal can be performed such that the newly formed surface after this material removal is parallel to the surface of the tool body located below it, i.e., at an angle ε = 0°, or at an angle different from 0° with this surface. If the above is satisfied, then, in exactly the same way as on the flank face, the coating thickness on the rake face is advantageously reduced such that the coating thickness of the hard coating increases with the increasing distance from this cutting edge starting from the cutting edge.

[0020] According to yet another advantageous embodiment of the invention, the removal of the hard coating on the rake face is performed such that 2° ≤ ε ≤ 10°, particularly advantageously 3° ≤ ε ≤ 6° holds with respect to the angle ε. According to yet another advantageous embodiment of the invention, the removal of the hard coating on the rake face is performed such that 2° ≤ ε ≤ 10°, particularly advantageously 3° ≤ ε ≤ 6° holds with respect to the angle ε.

[0021] According to yet another advantageous embodiment of the present invention, during the partial removal of the hard coating, the thickness of the hard coating on the rake face, is reduced such that the thickness of the hard coating increases with increasing spacing from the cutting edge, starting from the ground cutting edge.

[0022] According to yet another advantageous embodiment of the present invention, a diamond coating is vapor-deposited on the tool body as the hard coating. In that case, what is dealt with here is a crystalline or polycrystalline diamond coating. The latter polycrystalline diamond coating has a non-uniform distribution of the sizes of the crystalline domains (Domaenen). Instead of diamond, a hard coating consisting of DLC, for example a nitride-based material such as titanium nitride, other titanium-containing materials, or other materials suitable for hard coatings, can be deposited on the tool body. The abbreviation DLC stands for Diamond like Carbon. This form of hard coating is also referred to as amorphous diamond.

[0023] According to yet another advantageous embodiment of the present invention, the hard coating on the flank face is at least partially completely removed such that the tool body is exposed in that part. This is particularly true for the uncoated cutting edge of the tool body and, optionally, the region adjacent to this uncoated cutting edge. The hard coating is removed from the tool body at or in the vicinity of the cutting edge. By this, mechanical or thermal stresses between the tool body and the hard coating can be avoided or at least reduced.

[0024] According to yet another advantageous embodiment of the present invention, the hard coating on the rake face is at least partially completely removed so that the tool body is exposed in that part. Advantageously, the tool body is exposed within the region of the uncoated cutting edge of this tool body. By this, mechanical or thermal stresses between the tool body and the hard coating can be avoided.

[0025] According to yet another advantageous embodiment of the present invention, the laser processing is performed by a pulsed laser beam, and the pulse duration is between 50 ns and 150 fs. Processing with a laser pulse of such an ultra-short wave in this manner generates a locally limited extremely high energy density on the surface of the workpiece, and accordingly, the material can be removed without heat diffusing in an undesired manner within the workpiece.

[0026] According to yet another advantageous embodiment of the present invention, the pulse duration is between 190 fs and 10 ps.

[0027] According to yet another advantageous embodiment of the present invention, the pulse frequency is between 100 kHz and 1,000 kHz.

[0028] According to yet another advantageous embodiment of the present invention, the average laser output is between 4 W and 40 W. At a pulse duration between 190 fs and 10 ps, a pulse frequency between 100 kHz and 1,000 kHz, and an average laser output between 4 W and 40 W, the processing speed can be achieved between 10 mm / min and 40 mm / min with respect to the machine axis of a CNC-controlled laser processing apparatus.

[0029] According to yet another advantageous embodiment of the present invention, the pulse duration is between 6 ns and 45 ns, and the pulse frequency is between 15 kHz and 200 kHz. In this case, the average laser output is advantageously between 9 W and 18 W. In that case, for example, the machining speed can be achieved between 45 mm / min and 100 mm / min with respect to the machine axis of a CNC-controlled laser machining apparatus.

[0030] According to yet another advantageous embodiment of the present invention, the beam diameter of the laser beam at the focus is between 7 μm and 25 μm. The focus is advantageously located on the surface of the workpiece to be machined or in the vicinity of the surface of the workpiece to be machined.

[0031] According to yet another advantageous embodiment of the present invention, the tool body is made of carbide.

[0032] According to yet another advantageous embodiment of the present invention, the coating thickness of the hard coating in the region of the flank face and the rake face of the cutting edge where no material removal is performed is between 2 μm and 40 μm.

[0033] Yet other advantages and advantageous embodiments of the present invention can be seen from the following description, the drawings, and the claims.

[0034] In the figures, embodiments of the present invention are illustrated.

Brief Description of the Drawings

[0035]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

DETAILED DESCRIPTION OF THE INVENTION

[0036] Among FIGS. 1 to 10, the heads of the cutting tool at different points in the manufacture of the cutting tool are shown. The cutting tool is a square end mill (Vierkant-Schaftfraeser). FIGS. 1 and 2 show the head of the tool body 1 of the cutting tool without a hard coating. The tool body has a cutting edge portion 3 including a flank face 5 and a rake face 6 belonging thereto on the end side face of the tool body.

[0037] FIGS. 3, 4, and 5 show the cutting tool after the application (Auftrag) of the hard coating 2 onto the tool body 1. The hard coating extends over all the surfaces of the tool body 1 shown in FIG. 1. Due to the application of the hard coating, a previously rounded circular portion 4 is formed over the uncoated cutting edge portion 3 of the tool body 1. Adjacent to the previously rounded circular portion 4, a surface 7 of the hard coating 2 on the flank face 5 and a surface 11 of the hard coating 2 on the rake face 6 are located. The hard coating 2 has a uniform coating thickness within the portion shown in FIG. 5.

[0038] FIG. 5 shows that the edge radius of the previously rounded circular portion 4 is larger than the edge radius of the uncoated cutting edge portion 3 of the tool body 1. In order to reduce the edge radius of the coated cutting edge portion, the hard coating 2 is partially removed, and this cutting edge portion is ground after coating.

[0039] The removal of the hard coating is illustrated in FIGS. 6 to 10. First, as shown in FIGS. 6 and 7, a part of the hard coating on the flank face is removed, while the rake face remains unchanged first. For this purpose, the laser beam is oriented by the beam axis 15 of this laser beam such that the beam axis forms an angle δ with the first geometric plane 16. Within this first geometric plane 16, the surface 9 of the tool body 1 extends below the hard coating on the flank face 5. The surface 9 of this tool body 1 is delimited by the cutting edge 3 of the uncoated tool body 1. This surface is adjacent to the hard coating 2. The first geometric plane is not delimited. This first geometric plane extends beyond the surface 9 of the tool body 1. The initial course 7 of the surface of the hard coating 2 on the flank face 5 is shown by a dashed line. By partial material removal, a new surface 8 of the hard coating on the flank face is generated. This surface 8 extends within the second geometric plane 18. The first geometric plane 16 and the second geometric plane 18 are not parallel to each other. They intersect at a geometric line 20, and based on the viewing direction in FIG. 7 with respect to this geometric line, only one point is recognizable. The geometric line 20 extends outside the cutting tool. The first geometric plane 16 and the second geometric plane 18 form an angle δ. In this embodiment, the angle δ is 10°. The angle δ is shown in FIG. 7. By partial material removal of the flank face, a new ground cutting edge 10 is generated. FIG. 7 shows that the laser beam is oriented basically parallel or tangentially to the second geometric plane 18 by the beam axis 15 of this laser beam, and within this second geometric plane, the surface 8 of the hard coating generated by material removal on the flank face extends. FIG. 7 further shows that material removal starts within the flank face portion on the side opposite to the cutting edge portion and continues along the second geometric plane 18 until reaching the rake face.

[0040] FIG. 8 shows options for the orientation of the beam axis 15 of the laser beam according to FIG. 7. The laser beam is inclined by an angle α with respect to the beam axis 15 by the beam axis 15a of this laser beam, where this angle α corresponds to the half aperture angle of the laser beam. The angle α typically has a value between 1° and 10°.

[0041] FIGS. 9, 10, 11, and 12 show the cutting tool after a part of the hard coating 2 has been removed on the rake face additionally. The initial course 11 of the surface of the hard coating on the rake face is illustrated by a dashed line in FIG. 9. By partial material removal, a new surface 12 of the hard coating on the rake face is generated. This surface 12 is parallel to the surface 13 of the tool body 1 located below this surface. The surface 13 extends within the third geometric plane 17. The surface 12 extends within the fourth geometric plane 19. The angle ε between both surfaces 12 and 13 is, in that case, 0°. Correspondingly, the angle ε between the third geometric plane 17 and the fourth geometric plane 19 is likewise 0°. The third geometric plane 17 and the fourth geometric plane 19 do not intersect. By partial material removal on the rake face, a new ground cutting edge portion 14 is generated.

[0042] FIG. 10 shows an option with respect to FIG. 9. In that case, material is removed on the rake face such that the angle ε is different from 0°. The new surface 12a of the rake face hard coating generated by material removal is not parallel to the surface 13 of the tool body 1 located below this new surface. In the fourth geometric plane in which the new surface 12a extends, the fourth geometric plane 19a intersects the third geometric plane 17 along a straight line and forms an angle ε = 3° with the third geometric plane 17. A new ground cutting edge 14a is generated by partial material removal on the rake face.

[0043] Figure 13 shows how the laser beam is oriented during material removal on the flank face and the rake face by the beam axis of this laser beam when the cutting edge in question is located within the region of the end face of the cutting tool. The first orientation of the beam axis 30 is given during material removal on the flank face. This first orientation basically corresponds to the orientation of the beam axis 15 of the laser beam in FIG. 7 or the beam axis 15a of the laser beam in FIG. 8. The laser beam irradiates the surface of the hard coating 2 of the tool body 1 at point 32. Material removal starts within the part of the flank face opposite the cutting edge and ends on the rake face along the ground cutting edge. The advantage of this orientation of the laser beam is that the area irradiated by the laser beam in that area is completely removed. There is no irradiation position in the hard coating remaining on the cutting tool. Therefore, the surface on the flank face generated by material removal is extremely smooth. The same can be said regarding material removal on the rake face: that is, here, the beam axis 31 of the laser beam likewise has an orientation that is parallel to or tangential to the surface to be generated or forms an angle α between 1° and 10° with this surface. In this way, an extremely smooth surface of the hard coating can also be generated on the rake face. Material removal starts within the part of the rake face opposite the cutting edge and ends on the flank face along the ground cutting edge.

[0044] Figure 14 shows material removal in yet another cutting edge 23 of the cutting tool according to FIG. 3. In that case, the hard coating 2 on the tool body 1 is removed up to the rake face 26 starting from the flank face 25 so that a new surface 28 of the hard coating is generated at the flank face. This new surface 28 extends within a second geometric plane 38. The surface of the tool body 1 located below the hard coating 2 at the flank face 25 extends within a first geometric plane 36. The first geometric plane 36 and the second geometric plane 38 intersect at the cutting edge 23 of the tool body 1 under an angle δ. In the case in question here, the angle δ is 50°. Due to the material removal and the new surface 28 generated in that case, the hard coating at the cutting edge 23 of the tool body 1 is removed, and thus the cutting edge 23 does not have a hard coating.

[0045] Figures 15, 16, and 17 show partial material removal at the flank face and the rake face along the cutting groove (Spannut) 40 of the cutting tool according to FIGS. 1 to 12. Along this cutting groove 40, yet another cutting edge 43 having the respective flank face 45 and rake face 46 extends. Similarly, this cutting edge 43 is also ground by partial material removal after the adhesion of the hard coating. The cutting groove 40 is an elongate recess between two cutting edges, and these cutting edges extend in a spiral shape on the outer surface of the shaft of the cutting tool. From these two cutting edges, only this cutting edge 43 is visible within FIGS. 15 to 17. The other cutting edge is located on the side of the cutting tool opposite the observer. The cutting groove 40 serves for the accommodation of separated cutting chips during the entire cutting engagement of the cutting tool with a workpiece not shown in the figures.

[0046] FIG. 15 shows, in that case, how the laser beam is oriented by the geometric beam axis 47 of this laser beam in order to remove material at the flank face 45. In that case, the geometric beam axis 47 forms an angle β with the tangent 48 to the surface to be produced of the flank face 45. This angle typically corresponds to the half aperture angle of the laser beam. It is possible for this angle β to coincide with the angle α according to FIG. 8. However, this is not necessarily the case. Since the flank face 45 of the cutting edge 43 is located in the portion oriented outward of the cutting tool, the laser beam can be oriented by the geometric beam axis 47 of this laser beam basically in a plane extending perpendicular to the geometric cutting tool longitudinal axis.

[0047] FIGS. 16 and 17 show, in that case, how the laser beam is oriented by the geometric beam axis 49 of this laser beam in order to remove material at the rake face 46. FIG. 16 shows the orientation of the geometric beam axis at the start of material removal at the end face of the cutting tool. FIG. 17 shows the orientation of the geometric beam axis 49 when the material removal has already been advanced axially along the cutting groove 40. The geometric beam axis 49 is inclined by an angle γ with respect to the surfaces to be machined relative to the tangents 50, 51 in both cases. Since the rake face 46 is located on the surface of the cutting groove curved inward, the laser beam should be oriented differently with respect to the illustration according to FIG. 15 by the geometric beam axis 49 of this laser beam in order to irradiate at the intended position and in the tangential direction with respect to the surface of the cutting tool.

[0048] All features of the present invention can be essential for the invention individually as well as in any appropriate combination with each other. Note that although this application relates to the invention described in the claims, it may also include the following as other aspects. 1. A method for manufacturing a cutting tool, wherein the cutting tool has a tool body (1) provided with a hard coating (2), in the method wherein the hard coating (2) is deposited on the tool body (1) at least in regions of a cutting edge (10, 14, 14a, 43), a flank face (5, 25, 45), and a rake face (6, 26, 46), the following method steps: namely, deposition of a hard coating (2) on the surface of the tool body (1) of the cutting tool in a region of a cutting edge (3, 23, 43), the flank face (5, 25, 45) adjacent to the cutting edge (3, 23, 43), and the rake face (6, 26, 46) adjacent to the cutting edge (3, 23, 43), partial removal of the hard coating (2) in a region of the flank face (5, 25, 45) of the cutting edge by laser machining, a first geometric plane (16, 36) on which the surface (9) of the tool body (1) extends, which is located below the hard coating (2) of the flank face (5, 25, 45), and with respect to an angle δ between the first geometric plane (16, 36) and a second geometric plane (18, 38) on which the surface (8, 28) of the hard coating (2) extends, which is defined by the ground cutting edge (10, 14, 43) in the region of the flank face (5, 25, 45) after the removal, such that 1° ≤ δ ≤ 70° holds, grinding of the cutting edge to form a rounded circular part (4) provided with the hard coating (2), a method characterized by the method steps. 2. The method according to 1 above, characterized in that the hard coating (2) is deposited on the tool body (1) with a coating thickness between 2 μm and 40 μm. 3. The removal of the hard coating (2) is carried out such that 2° ≤ δ ≤ 10°, particularly preferably 3° ≤ δ ≤ 6° holds with respect to the angle δ, the method according to 1 or 2 above. 4. When performing the partial removal of the hard coating (2), the thickness of the hard coating (2) on the flank face (5, 25, 45) is such that the thickness of the hard coating (2) increases with an increasing distance from the ground cutting edge portion (10, 14, 14a, 43) starting from the ground cutting edge portion (10, 14, 14a, 43), The method according to any one of the above 1 to 3, characterized in that it is reduced. 5. When performing the laser processing, the laser beam is by the geometric beam axis (15, 15a, 30, 31, 47, 49) of this laser beam, such that the geometric beam axis forms an angle δ with the first geometric plane (16, 36), The method according to any one of the above 1 to 4, characterized in that it is oriented. 6. When performing the laser processing, the laser beam is by the geometric beam axis (15, 15a, 30, 31, 47, 49) of this laser beam, such that this laser beam forms an angle α with the second geometric plane (18, 38), and with respect to this angle, 1° ≤ α ≤ 10° holds, The method according to any one of the above 1 to 5, characterized in that it is oriented. 7. The material removal of the hard coating (2) on the flank face (5, 25, 45) of the hard coating (2) is started within a portion of the flank face (5, 25, 45) spaced apart from the cutting edge portion (3, 23) of the tool body (1) and ended at the rake face (6, 26, 46). The method according to any one of the above 1 to 6, characterized in that it is so. 8. The cutting edge portion (10, 14, 14a, 43) provided with the hard coating (2) is by additional partial removal of the hard coating (2) within the region of the rake face (6, 26, 46) by laser processing, with respect to the angle ε between the third geometric plane (17) on which the surface (9) of the tool body (1) located below the hard coating (2) on the rake face (6, 46) extends and the fourth plane (19) on which the surface (12) of the hard coating (2) partitioned by the ground cutting edge portion (14, 43) within the region of the rake face (6) after the removal extends, such that 0° ≤ ε ≤ 70° holds, The method according to any one of the above 1 to 7, characterized in that it is ground. 9. The removal of the hard coating (2) is performed such that, with respect to the angle ε, 2° ≤ ε ≤ 10°, particularly preferably 3° ≤ ε ≤ 6°, according to the method as claimed in claim 8 above. 10. During the partial removal of the hard coating (2), the thickness of the hard coating (2) on the rake face (6, 46) is reduced such that the thickness of the hard coating (2) increases with increasing distance from the ground cutting edge (14, 43) starting from the ground cutting edge (14, 43). The method as claimed in claim 8 or 9 above, characterized in that it is reduced. 11. The method as claimed in any one of claims 1 to 10 above, characterized in that a diamond coating is deposited on the tool body (1) as the hard coating (2). 12. The hard coating (2) on the flank face (5, 25, 45) is at least partially completely removed such that the tool body (1) is exposed at that part. The method as claimed in any one of claims 1 to 11 above, characterized in that it is completely removed. 13. The hard coating (2) on the rake face (6, 26, 46) is at least partially completely removed such that the tool body (1) is exposed at that part. The method as claimed in any one of claims 1 to 12 above, characterized in that it is completely removed. 14. The laser processing is performed by a pulsed laser beam, and the pulse duration is between 50 ns and 150 fs, according to the method as claimed in any one of claims 1 to 13 above. 15. The method as claimed in claim 14 above, characterized in that the pulse duration is between 190 fs and 10 ps. 16. The method as claimed in claim 14 or 15 above, characterized in that the pulse frequency is between 100 kHz and 1,000 kHz. 17. The method as claimed in any one of claims 1 to 16 above, characterized in that the average laser power is between 4 W and 40 W. 18. The method as claimed in claim 15 above, characterized in that the pulse duration is between 6 ns and 45 ns and the pulse frequency is between 15 kHz and 200 kHz. 19. The method as claimed in claim 18 above, characterized in that the average laser power is between 9 W and 18 W. 20. The method according to any one of 1 to 19 above, characterized in that the beam diameter of the laser beam at the focal point is between 7 μm and 25 μm.

Explanation of Symbols

[0049] 1 Tool body 2 Hard coating 3 Cutting edge part of the tool body 4 Rounded circular part at the tip 5 Relief surface 6 Rake surface 7 Initial progress of the surface of the hard coating on the relief surface 8 Progress of the surface of the hard coating on the relief surface after partial material removal 9 Surface of the tool body on the relief surface 10 Finished and coated cutting edge part 11 Initial progress of the surface of the hard coating on the rake surface 12 Progress of the surface of the hard coating on the rake surface after partial material removal 12a Progress of the surface of the hard coating on the rake surface after partial material removal in one option 13 Surface of the tool body on the rake surface 14 Finished and coated cutting edge part 14a Finished and coated cutting edge part in one option 15 Geometric beam axis of the laser beam 15a Geometric beam axis of the laser beam 16 First geometric plane 17 Third geometric plane 18 Second geometric plane 19 Fourth geometric plane 19a Fourth geometric plane in one option 20 Geometric line, within which the first geometric plane and the second geometric plane intersect 23 Cutting edge of the tool body 25 Relief surface 26 Rake surface 28 Course of the surface of the hard coating on the relief surface after partial material removal 30 First orientation of the beam axis of the laser beam 31 Second orientation of the beam axis of the laser beam 32 Irradiation point of the laser beam on the surface of the hard coating 36 First geometric plane 38 Second geometric plane 40 Cutting groove 43 Cutting edge 45 Relief surface 46 Rake surface 47 Geometric beam axis of the laser beam 48 Tangent to the surface of the relief surface to be machined 49 Geometric beam axis of the laser beam 50 Tangent to the surface of the relief surface to be machined 51 Tangent to the surface of the relief surface to be machined

Claims

1. A method for manufacturing a cutting tool, wherein the cutting tool has a tool body (1) provided with a hard coating (2), in the method, the hard coating (2) is deposited on the tool body (1) at least in the regions of the cutting edges (10, 14, 14a, 43), the flank faces (5, 25, 45), and the rake faces (6, 26, 46), the following method steps: namely, depositing a hard coating (2) on the surface of the tool body (1) of the cutting tool in the region of the cutting edge (3, 23, 43), the flank face (5, 25, 45) adjacent to the cutting edge (3, 23, 43), and the rake face (6, 26, 46) adjacent to the cutting edge (3, 23, 43); partially removing the hard coating (2) in the region of the flank face (5, 25, 45) of the cutting edge by laser machining; a first geometric plane (16, 36) on which the surface (9) of the tool body (1) extends, the surface (9) being located below the hard coating (2) of the flank face (5, 25, 45); with respect to the angle δ between the first geometric plane (16, 36) and a second geometric plane (18, 38) on which the surface (8, 28) of the hard coating (2) extends, the second geometric plane (18, 38) being defined by the ground cutting edge (10, 14, 43) in the region of the flank face (5, 25, 45) after the removal, 1° ≤ δ ≤ 70° holds; grinding the cutting edge to form a rounded circular portion (4) provided with the hard coating (2); A method characterized by the method steps.

2. The method according to claim 1, characterized in that the hard coating (2) is deposited on the tool body (1) with a coating thickness between 2 μm and 40 μm.

3. The removal of the hard coating (2) is carried out such that with respect to the angle δ, 2° ≤ δ ≤ 10°, particularly preferably 3° ≤ δ ≤ 6° holds. The method according to claim 1 or 2.

4. During the partial removal of the hard coating (2), the thickness of the hard coating (2) on the flank face (5, 25, 45) increases with an increasing distance from the ground cutting edge (10, 14, 14a, 43) starting from the ground cutting edge (10, 14, 14a, 43). The method according to any one of claims 1 to 3, characterized in that it is reduced.

5. During the laser machining, the laser beam is defined by the geometric beam axis (15, 15a, 30, 31, 47, 49) of this laser beam, such that the geometric beam axis forms an angle δ with the first geometric plane (16, 36), The method according to any one of claims 1 to 4, characterized in that it is oriented.

6. During the laser machining, the laser beam is defined by the geometric beam axis (15, 15a, 30, 31, 47, 49) of this laser beam, such that this laser beam forms an angle α with the second geometric plane (18, 38), and 1° ≤ α ≤ 10° holds with respect to this angle, The method according to any one of claims 1 to 5, characterized in that it is oriented.

7. The material removal of the hard coating (2) on the relief surface (5, 25, 45) of the hard coating (2) starts within a portion of the relief surface (5, 25, 45) spaced from the cutting edge portion (3, 23) of the tool body (1) and ends at the rake surface (6, 26, 46). The method according to any one of claims 1 to 6, characterized in that it is like this.

8. The cutting edge portion (10, 14, 14a, 43) provided with the hard coating (2) by additional partial removal of the hard coating (2) within the region of the rake surface (6, 26, 46) by laser machining, with respect to the angle ε between the third geometric plane (17) in which the surface (9) of the tool body (1) located below the hard coating (2) on the rake surface (6, 46) extends and the fourth plane (19) in which the surface (12) of the hard coating (2) defined by the ground cutting edge portion (14, 43) within the region of the rake surface (6) after the removal extends, such that 0° ≤ ε ≤ 70° holds, The method according to any one of claims 1 to 7, characterized in that it is ground.

9. The removal of the hard coating (2) is carried out such that 2° ≤ ε ≤ 10°, particularly preferably 3° ≤ ε ≤ 6° holds with respect to the angle ε. The method according to claim 8, characterized in that it is like this.

10. During the partial removal of the hard coating (2), The thickness of the hard coating (2) on the rake face (6, 46) is such that the thickness of the hard coating (2) increases with increasing separation from the ground cutting edge portions (14, 43) starting from the ground cutting edge portions (14, 43). The method according to claim 8 or 9, characterized in that it is reduced.

11. The method according to any one of claims 1 to 10, characterized in that a diamond film is deposited on the tool body (1) as the hard coating (2).

12. The hard coating (2) on the flank face (5, 25, 45) is at least partially such that the tool body (1) is exposed in that part. The method according to any one of claims 1 to 11, characterized in that it is completely removed.

13. The hard coating (2) on the rake face (6, 26, 46) is at least partially such that the tool body (1) is exposed in that part. The method according to any one of claims 1 to 12, characterized in that it is completely removed.

14. The laser processing is performed by a pulsed laser beam, and the pulse duration is between 50 ns and 150 fs. The method according to any one of claims 1 to 13, characterized in that it is between 50 ns and 150 fs.

15. The method according to claim 14, characterized in that the pulse duration is between 190 fs and 10 ps.

16. The method according to claim 14 or 15, characterized in that the pulse frequency is between 100 kHz and 1,000 kHz.

17. The method according to any one of claims 1 to 16, characterized in that the average laser output is between 4 W and 40 W.

18. The method according to claim 15, characterized in that the pulse duration is between 6 ns and 45 ns and the pulse frequency is between 15 kHz and 200 kHz.

19. The method according to claim 18, characterized in that the average laser output is between 9 W and 18 W.

20. The method according to any one of claims 1 to 19, characterized in that the beam diameter of the laser beam at the focus is between 7 μm and 25 μm.

Images