Method for manufacturing cutting tools

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 comprises a tool body provided with a hard coating. Background Art

[0002] Cutting tools include cutting tools for chip-forming manufacturing methods and tools for cutting. These tools usually have a shank and a cutting portion. In this case, at least one end portion of the shank is used for holding the cutting tool, for example in a machine interface of a machining tool. The cutting portion is arranged on this shank. The cutting portion has at least one cutting edge, by means of which the cutting tool is brought into interaction with the workpiece to be machined and removes material from the workpiece in this process. For example, milling cutters, drills, reamers, bits, scrapers, planes and saws are considered to be part of this type of cutting tool. In this case, the cutting tool is a solid tool, which consists of a single consistent material. Alternatively, it is also possible for the cutting portion to have an insert provided with the cutting edge, wherein the insert consists of a material different from that of the shank. At the places where they are used, cutting tools are under the influence of significant mechanical and thermal loads based on the forces acting on them and the temperatures generated. Mechanical friction, oxidation, abrasion, diffusion especially at high machining speeds, and scaling are considered part of these. This induces wear of the cutting tool in the region of the cutting edge.

[0003] To improve the wear resistance of cutting tools and increase their service life, cutting tools are provided with a hard coating in the area of ​​the cutting edge. This hard coating is applied (aufgebracht) to the tool body. For example, amorphous carbon coatings, known as diamond-like carbon (DLC), and titanium coatings are considered part of this type of hard coating. These are applied to the tool body, for example, by chemical vapor deposition (CVD). After the hard coating is deposited (Abscheiden), the coated cutting edge has a rounded, circular tip. To achieve the desired edge radius, this rounded, circular tip needs to be subsequently ground down. For this purpose, a portion of the hard coating is removed within the area of ​​the cutting edge. Sharpening the cutting edge by removing a portion of the hard material from the surface of the cutting tool can be performed, for example, by a laser processing device. This material removal is also called laser ablation or laser evaporation. The material can be removed, for example, in a planar, layered manner. In this case, the laser beam is basically aligned perpendicular to the plane, and a portion of the hard coating is removed on this plane. The flank or rake face is what is being dealt with here. This type of method is known, for example, from Patent Documents 1 and 2. Furthermore, there is the possibility of separating a portion of the hard coating with a continuous or pulsed laser beam, in which case the laser beam is basically aligned parallel to the surface to be removed. This type of method is known, for example, from Patent Document 3. In this case, the laser beam can be aligned over the cutting tool to be machined so that it starts within the region of the cutting edge where material removal is to be generated, as illustrated in Figure 1 of Patent Document 3. This is also called material removal from the front. In contrast, as illustrated in Figure 3 of Patent Document 3, material removal can selectively be initiated on the side of the cutting tool opposite to the cutting edge to be generated. This is also referred to as material removal from the rear. The laser emission parameters must be adapted to the material to be processed and to the desired processing. Material removal can be performed on the flank, rake, or both of these surfaces.

[0004] The grinding of the coated cutting edge is typically performed so that the wedge angle of the uncoated tool body's cutting edge wedge, formed by the flank and rake face, matches the wedge angle of the coated and post-ground cutting edge wedge. However, this procedure has the drawback that, when aligning the laser beam parallel to the surface to be created and removing material from the rear, the laser beam may be deflected in an undesirable manner on a secondary flank or on other surfaces of the cutting tool that do not correspond to either the flank or the rake face. This type of deflection of the laser beam can cause laser processing to fail to achieve the desired sharpness on the cutting edge. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] German Patent Application Publication No. 10 2009 004 316 Specification A1 [Patent Document 2] German Patent Application Publication No. 10, 2011 076 584, Specification A1 [Patent Document 3] European Patent Application Publication No. 2 682 219 Specification A1 [Overview of the project] [Problems that the invention aims to solve]

[0006] The fundamental problem of this invention is to provide a method for manufacturing hard-coated cutting tools. In this method, the pre-defined edge radius of the coated cutting edge can be reliably obtained even when a portion of the hard coating is removed by a laser beam for sharpening the coated cutting edge. In this configuration, the laser beam is aligned with the surface to which the cutting tool is to be created, rather than perpendicular to it, and material removal can also be performed from the rear. [Means for solving the problem]

[0007] This problem is solved by a method for manufacturing a cutting tool having the features of claim 1. This method ensures that, after partial material removal, the surface of the hard coating within the relief area is not parallel to the surface of the tool body located beneath this hard coating, but rather... A first geometric plane on which the surface of the tool body, located below the hard coating of the relief surface, extends, After removal, the second geometric plane on which the surface of the hard coating extends, demarcated by the sharpened cutting edge within the relief surface region, forms an angle δ, and with respect to this angle, 1° ≤ δ ≤ 70° holds. It is characterized by the following. In that case, it is considered that the surface of the tool body located beneath the coating on the flank ends at the uncoated cutting edge, and that the geometric plane to which the surface of the tool body extends extends infinitely far beyond this. After partial material removal, the surface of the hard coating within the flank region ends at the ground cutting edge, and the second geometric plane extends infinitely far beyond this. The first geometric plane and the second geometric plane intersect along a geometric straight line. This geometric straight line is - Does it align with the uncoated cutting edge of the tool body? - Does it match the sharpened cutting edge of the cutting tool? - Extending outwards from the tool body and inside the hard coating on the rake face, or - It extends outward from the cutting tool. [Effects of the Invention]

[0008] The surface of the hard coating within the flank area is advantageously sloped such that, after the completion of material removal, the thickness of the hard coating on the flank increases with increasing distance from the cutting edge, starting from the cutting edge. When a hard coating with a uniform film thickness is deposited on the cutting edge, flank, and rake face, a certain amount of material removal is necessary only in the immediate vicinity of the cutting edge during subsequent post-sharpening of the cutting edge. The amount of hard coating material to be removed decreases with increasing distance from the cutting edge. This results in a cutting edge with a predetermined radius, while simultaneously leaving more hard coating material on the cutting tool. Since less material needs to be removed, the material removal is performed in a shorter time.

[0009] A cutting tool can be elongated and extend along its geometric longitudinal axis. For example, a milling cutter or drill is considered part of this type of cutting tool. At least one cutting edge can be either the main cutting edge (Hauptschneide) or the secondary cutting edge (Nebenschneide). This cutting edge can be located on the end face side of a vertically elongated cutting tool, or it can extend along the shaft within the area of ​​the cutting groove.

[0010] The hard coating material is removed by laser processing. For this purpose, the laser beam of the laser processing machine is aligned at a predetermined angle relative to the surface of the hard coating on the flank to partially remove the hard coating. In this case, the angle at which the laser beam is aligned relative to the surface of the cutting tool being coated by the geometric beam axis of the laser beam depends on the angle δ, and this angle is formed by the first geometric plane and the second geometric plane after the completion of material removal. Advantageously, the laser beam is aligned such that its geometric beam axis extends parallel to or tangentially to the surface to be generated in the flank. Since the laser beam is typically focused onto the surface of the cutting tool, the aperture angle of the laser beam is taken into consideration in an advantageous manner when aligning this laser beam. If the hard coating has a uniform film thickness after adhesion within the flank area, the laser beam can be aligned at an angle δ relative to the surface to be created at the start of material removal, by the geometric beam axis of the laser beam. If the aperture angle of the focused laser beam is considered, this angle corresponds to the sum of half the aperture angle and angle δ. In this case, the removal of the hard coating can in particular be carried out from the rear side. This means that the removal starts in the flank portion on the side opposite to the sharp cutting edge to be produced. Undesired deflection of the laser beam is thereby avoided. Furthermore, it is ensured that all positions of the cutting tool irradiated by the laser beam are removed throughout the material removal process. The surface produced on the flank is therefore smooth. This produced surface has good surface quality. A sharpened cutting edge with a predefined edge radius can be produced with the desired quality.

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

[0012] According to yet another advantageous embodiment of the present invention, the removal of the hard coating is With respect to the angle δ, the removal is performed such that 2°≦δ≦10°, particularly preferably 3°≦δ≦6° holds true. This angle δ typically depends on the coating thickness of the hard coating on the flank, the material of the hard coating, and the wedge angle of the cutting edge wedge.

[0013] According to yet another advantageous embodiment of the present invention, the removal of the hard coating is With respect to the angle δ, the removal is performed such that 30°≦δ≦70° holds true. This range for 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. Thereby, mechanical or thermal stress between the tool body and the hard coating is avoided.

[0014] In yet another advantageous embodiment of the present invention, when the hard coating is partially removed, the thickness of the hard coating on the relief surface is The thickness of the hard coating increases with increasing distance from the ground cutting edge, starting from the ground cutting edge. It will be reduced.

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

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

[0017] In yet another advantageous embodiment of the present invention, during the laser processing, the laser beam is directed along the beam axis of the laser beam. This laser beam is directed such that it forms an angle α with the second geometric plane, and that 1° ≤ α ≤ 10° with respect to this angle. In that case, it is possible that the laser beam is focused onto the surface of the workpiece and therefore has an aperture angle. Advantageously, angle α corresponds to half the aperture angle of the laser beam.

[0018] In yet another advantageous embodiment of the present invention, the removal of the material of the hard coating on the relief surface of the hard coating is performed as follows: The process begins within the relief face portion, spaced apart from the cutting edge, and ends at the rake face. In this case, material removal is performed from the rear.

[0019] In yet another advantageous embodiment of the present invention, the cutting edge having the hard coating is further reduced by additional, partial removal of the hard coating within the rake face region. A third geometric plane to which the surface of the tool body, located below the hard coating on the rake face, extends, The surface is ground after the partial material removal, such that the angle ε between the rake face region and the fourth geometric plane on which the surface of the hard coating extends, demarcated by the ground cutting edge, satisfies 0° ≤ ε ≤ 70°. In that case, angle δ can be the same as angle ε in terms of magnitude, or it can be different from angle ε. In this case, the thickness of the hard coating is reduced not only on the flank face but also on the rake face, due to the post-sharpening of the cutting edges after the deposition of the hard coating. In this case, material removal may be performed such that the newly formed surface after 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 conditions are met, then, just as on the flank face, the coating thickness on the rake face is advantageously reduced such that the thickness of the hard coating increases with increasing distance from the cutting edge, starting from the cutting edge.

[0020] In yet another advantageous embodiment of the present invention, the removal of the hard coating on the scoop surface is performed as follows: The angle ε is treated such that 2°≦ε≦10°, and more favorably, 3°≦ε≦6°, holds true.

[0021] In yet another advantageous embodiment of the present invention, when partially removing the hard coating, The thickness of the hard coating on the scoop surface is The thickness of the hard coating is reduced such that it increases with increasing distance from the ground cutting edge, starting from the ground cutting edge.

[0022] In yet another advantageous embodiment of the present invention, a diamond coating is deposited on the tool body as a hard coating. In this case, the subject being discussed is crystalline or polycrystalline diamond coating. The latter, polycrystalline diamond coating, has a non-uniform distribution of crystalline domain (Domaenen) sizes. Instead of diamond, a hard coating consisting of a nitride-based material such as DLC, titanium nitride, other titanium-containing materials, or other materials suitable for hard coating may be applied to the tool body. The abbreviation DLC stands for Diamond-Like Carbon. This type of hard coating is also known as amorphous diamond.

[0023] In yet another advantageous embodiment of the present invention, the hard coating on the relief surface is at least partially The tool body is completely removed so that it is exposed in that portion. This is especially true for the uncoated cutting edges of the tool body, and, in some cases, the areas adjacent to these uncoated cutting edges. The hard coating is removed from the tool body at or near the cutting edge. This can avoid, or at least reduce, mechanical or thermal stress between the tool body and the hard coating.

[0024] In yet another advantageous embodiment of the present invention, the hard coating on the scoop surface is at least partially, The tool body is completely removed so that it is exposed in that portion. Advantageously, the tool body is exposed within the area of ​​the uncoated cutting edge of the tool body. This can avoid mechanical or thermal stress between the tool body and the hard coating.

[0025] In yet another advantageous embodiment of the present invention, the laser processing is performed by a pulsed laser beam, the pulse duration being between 50 ns and 150 fs. This type of processing using ultra-short wave laser pulses has the advantage of generating a locally limited and extremely high energy density on the surface of the workpiece, and consequently, the material can be removed without heat diffusing in an undesirable manner within the workpiece.

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

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

[0028] In yet another advantageous embodiment of the present invention, the average laser power is between 4W and 40W. With pulse durations between 190 fs and 10 ps, ​​pulse frequencies between 100 kHz and 1,000 kHz, and average laser power between 4 W and 40 W, processing speeds can be achieved between 10 mm / min and 40 mm / min with respect to the machine axis of a CNC-controlled laser processing machine.

[0029] In 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 power is advantageously between 9 W and 18 W. In that case, for example, the processing speed can be achieved between 45 mm / min and 100 mm / min with respect to the machine axis of the CNC-controlled laser processing device.

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

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

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

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

[0034] An embodiment of the present invention is illustrated in the figure. [Brief explanation of the drawing]

[0035] [Figure 1] This is a perspective view of a cutting tool without a hard coating. [Figure 2] This is a partial view of a cutting tool according to Figure 1. [Figure 3] This is a perspective view of the cutting tool according to Figure 1, immediately after the hard coating has been applied and before the cutting edges have been sharpened. [Figure 4] This is a partial view of a cutting tool according to Figure 3. [Figure 5] This is a cross-sectional view of the cutting tool according to Figure 3, within the region of the cutting edge on the end surface. [Figure 6] This is a cross-sectional view according to Figure 5, in which the hard coating is partially removed on the relief surface of the cut edge. [Figure 7] This is a diagram following Figure 6, with angle δ. [Figure 8] This is a diagram following Figure 6, with angle α. [Figure 9] Figures 3 and 5 show cross-sectional views of the cutting tool, in which the hard coating is partially removed from the relief face and rake face of the cutting edge. [Figure 10] Figures 3 and 5 show cross-sectional views of the cutting tool, in which the hard coating is partially removed on the flank face of the cutting edge and on the rake face in a manner different from that shown in Figure 9. [Figure 11] Figure 3 shows a cutting tool, in which the hard coating is partially removed on the relief face and rake face of the cutting edge, as shown in Figure 9. [Figure 12] This is a partial view of the tool body, as shown in Figure 11. [Figure 13] Figures 6 to 12 show the alignment of the laser beam during material removal in a cutting tool, where this material removal is performed within the region of the cutting edge on the end face side of the cutting tool. [Figure 14] Figure 3 shows yet another cutting edge of the cutting tool. [Figure 15] These figures show the alignment of the laser beam during material removal with a cutting tool, according to Figures 6 to 12, on the relief surface of the cutting edge within the cutting groove region. [Figure 16] This diagram shows the alignment of the laser beam during material removal with a cutting tool according to Figures 6 to 12, at the start of material removal, within the cutting groove region, and on the rake face of the cutting edge. [Figure 17] This diagram shows the material removal process in progress at the rake face within the cutting edge region of the cutting groove, as shown in Figure 16. [Modes for carrying out the invention]

[0036] Figures 1 through 10 illustrate the head of a cutting tool at different points in its manufacturing process. The cutting tool is a square end mill (Vierkant-Schaftfraeser). Figures 1 and 2 show the head of the tool body 1 of a cutting tool without a hard coating. The tool body has a cutting edge portion 3 at its end surface, which includes a relief face 5 and a rake face 6.

[0037] Figures 3, 4, and 5 show the cutting tool after the hard coating 2 has been applied (Auftrag) to the tool body 1. The hard coating extends over all surfaces of the tool body 1 as shown in Figure 1. The hard coating adheres to the tool body 1, forming a rounded circular portion 4 across the uncoated cutting edge 3. Adjacent to the rounded circular portion 4 are the surface 7 of the hard coating 2 on the flank 5 and the surface 11 of the hard coating 2 on the rake face 6. The hard coating 2 has a uniform film thickness within the portion shown in Figure 5.

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

[0039] The removal of the hard coating is illustrated in Figures 6 to 10. Firstly, as shown in Figures 6 and 7, a portion of the hard coating on the flank surface is removed, while the rake surface remains unchanged. For this purpose, the laser beam is aligned such that its beam axis 15 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 beneath the hard coating on the flank 5. This surface 9 of the tool body 1 is demarcated 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 demarcated. This first geometric plane extends beyond the surface 9 of the tool body 1. The initial elapsed 7 of the surface of the hard coating 2 on the flank 5 is shown by a dashed line. Partial material removal creates a new surface 8 of hard coating on the flank. This surface 8 extends within a second geometric plane 18. The first geometric plane 16 and the second geometric plane 18 are not parallel to each other. They intersect in a geometric line 20, and with respect to this geometric line, only one point is recognizable based on the direction of gaze in Figure 7. A geometric line 20 extends outward from 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 illustrated in Figure 7. Partial material removal from the flank creates a new, sharpened cutting edge 10. Figure 7 shows that the laser beam is aligned by its beam axis 15 in a direction that is essentially parallel or tangential to the second geometric plane 18, and that the surface 8 of the hard coating, which is created by material removal at the flank, extends within this second geometric plane. Figure 7 further shows that material removal begins in the flank portion opposite the cutting edge and continues along the second geometric plane 18 until it reaches the rake face.

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

[0041] Figures 9, 10, 11, and 12 show the cutting tool after an additional portion of the hard coating 2 has been removed from the rake face. The initial state of the hard coating surface on the rake face 11 is illustrated by a dashed line in Figure 9. Partial material removal creates a new surface 12 of hard coating on the rake face. This surface 12 is parallel to the surface 13 of the tool body 1, which is located beneath it. Surface 13 extends within the third geometric plane 17. Surface 12 extends within the fourth geometric plane 19. The angle ε between both surfaces 12 and 13 is 0° in this case. Correspondingly, the angle ε between the third geometric plane 17 and the fourth geometric plane 19 is also 0°. The third geometric plane 17 and the fourth geometric plane 19 do not intersect. Partial material removal on the rake face generates a new, sharpened cutting edge 14.

[0042] Figure 10 shows an alternative to Figure 9. In this case, the material is removed such that the angle ε is different from 0° at the rake face. 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 beneath this new surface. The new surface 12a extends within the fourth geometric plane, which intersects the third geometric plane 17 along a straight line and forms an angle ε = 3° with the third geometric plane 17. Partial material removal at the rake face generates a new, sharpened cutting edge 14a.

[0043] Figure 13 shows how the laser beam is aligned by its beam axis during material removal on the flank and rake faces when the cutting edge to which it belongs is located within the region of the end face of the cutting tool. The first alignment of the beam axis 30 is given during material removal on the flank face. This first alignment essentially corresponds to the alignment of the laser beam axis 15 in Figure 7, or the laser beam axis 15a in Figure 8. The laser beam is directed at point 32 onto the surface of the hard coating 2 of the tool body 1. Material removal begins in the flank portion opposite the cutting edge and ends at the rake face along the sharpened cutting edge. The advantage of this laser beam alignment is that the area irradiated by the laser beam is completely removed. There are no irradiation points in the hard coating remaining on the cutting tool. Therefore, the surface on the flank, generated by material removal, is extremely smooth. The same can be said for material removal on the scoop face: that is, Here, the beam axis 31 of the laser beam similarly has one orientation, which is either parallel to or tangential to the surface to be generated, or forms an angle α between 1° and 10° with respect to this surface. In this way, an extremely smooth surface of the hard coating can be produced even on the rake face. Material removal begins in the portion of the rake face opposite the cutting edge and ends on the flank face along the sharpened cutting edge.

[0044] Figure 14 shows material removal at yet another cutting edge 23 of the cutting tool according to Figure 3. In this case, the hard coating 2 on the tool body 1 is removed starting from the flank face 25 and continuing down to the rake face 26, so that a new surface 28 of the hard coating is generated on the flank face. This new surface 28 extends within a second geometric plane 38. The surface of the tool body 1, located beneath the hard coating 2 on the flank surface 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 at an angle δ. In the case at hand, the angle δ is 50°. The hard coating on the cutting edge 23 of the tool body 1 is removed by the material removal and the new surface 28 that is generated in the process, and therefore the cutting edge 23 does not have a hard coating.

[0045] Figures 15, 16, and 17 show partial material removal along the flank and rake face of a cutting tool according to Figures 1 to 12. Another cutting edge 43 extends along this cutting groove 40, having its own flank face 45 and rake face 46. Similarly, this cutting edge 43 is also ground by partial material removal after the hard coating has been applied. The cutting groove 40 is a vertically elongated recess between two cutting edges, which extend in a spiral shape along the outer surface of the cutting tool shaft. Of these two cutting edges, only this cutting edge 43 is visible in Figures 15 to 17. The other cutting edge is located on the side of the cutting tool opposite the observer. The cutting groove 40 serves to contain separated cutting chips during the cutting engagement of the cutting tool with a workpiece not shown in the figure.

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

[0047] Figures 16 and 17 show how, in that case, the laser beam is aligned by the geometric beam axis 49 of the laser beam in order to remove material at the rake face 46. Figure 16 shows the alignment of the geometric beam axis at the start of material removal on the end face of the cutting tool. Figure 17 shows the alignment of the geometric beam axis 49 when material removal has already progressed axially along the cutting groove 40. In both of these cases, the geometric beam axis 49 is inclined by an angle γ with respect to the surface to be machined, relative to the tangents 50 and 51. Since the rake face 46 is located on the surface of the cutting groove, which is curved inward, the laser beam should be aligned with the geometric beam axis 49 of the laser beam, differently from the illustration shown in Figure 15, in order to illuminate the laser beam at the intended position and tangentially to the surface of the cutting tool.

[0048] All features of this invention can be essential to the invention, both individually and in appropriate combinations of each other. While this application relates to the invention described in the claims, it may also encompass the following other embodiments. 1. A method for manufacturing cutting tools, This cutting tool has a tool body (1) with a hard coating (2), In the method described above, the hard coating (2) is attached to the tool body (1) in at least the area of ​​the cutting edges (10, 14, 14a, 43), the relief faces (5, 25, 45), and the rake faces (6, 26, 46), The following are the steps of the method: Deposition of a hard coating (2) on the surface of the tool body (1) of the cutting tool within the region between the cutting edges (3, 23, 43), the relief faces (5, 25, 45) adjacent to the cutting edges (3, 23, 43), and the rake faces (6, 26, 46) adjacent to the cutting edges (3, 23, 43), By laser processing, the hard coating (2) is partially removed within the area of ​​the relief surface (5, 25, 45) of the cutting edge, A first geometric plane (16, 36) on which the surface (9) of the tool body (1) extends, located below the hard coating (2) of the relief surface (5, 25, 45), With respect to the angle δ between the second geometric plane (18, 38) on which the surface (8, 28) of the hard coating (2) extends, which is demarcated by the sharpened cutting edges (10, 14, 43) within the region of the relief face (5, 25, 45) after the removal, such that 1° ≤ δ ≤ 70° holds, Sharpening of the cutting edge portion that forms a rounded circular portion (4) having the hard coating (2), A method characterized by the steps of the method. 2. The method according to claim 1, characterized in that a hard coating (2) is deposited onto the tool body (1) with a film thickness between 2 μm and 40 μm. 3. The removal of the hard coating (2) is performed as follows: The method according to 1 or 2 above, characterized in that, with respect to the angle δ, 2° ≤ δ ≤ 10°, and particularly favorably 3° ≤ δ ≤ 6°, is satisfied. 4. When partially removing the hard coating (2), the thickness of the hard coating (2) on the relief surfaces (5, 25, 45) is: The thickness of the hard coating (2) increases with increasing distance from the ground cutting edges (10, 14, 14a, 43), starting from the ground cutting edges (10, 14, 14a, 43). The method according to any one of the above 1 to 3, characterized by being reduced. 5. During the laser processing described above, the laser beam is directed along the geometric beam axis (15, 15a, 30, 31, 47, 49) of the laser beam. The geometric beam axis makes the angle δ with the first geometric plane (16, 36), The method according to any one of the above 1 to 4, characterized by being aligned. 6. During the laser processing described above, the laser beam is directed along the geometric beam axis (15, 15a, 30, 31, 47, 49) of the laser beam. This laser beam forms an angle α with the second geometric plane (18, 38), such that 1° ≤ α ≤ 10° holds true with respect to this angle. The method according to any one of items 1 to 5 above, characterized by being aligned. 7. The removal of the material from the hard coating (2) at the relief surfaces (5, 25, 45) of the hard coating (2) is performed as follows: The method according to any one of 1 to 6 described above, characterized in that it starts in a portion of the relief face (5, 25, 45) spaced apart from the cutting edge portion (3, 23) of the tool body (1), and ends at the rake face (6, 26, 46). 8. The cutting edges (10, 14, 14a, 43) having the hard coating (2) are further partially removed by laser processing within the area of ​​the rake face (6, 26, 46). A third geometric plane (17) to which the surface (9) of the tool body (1) located below the hard coating (2) of the rake face (6, 46) extends, With respect to the angle ε between the fourth plane (19) on which the surface (12) of the hard coating (2) extends, which is demarcated by the sharpened cutting edges (14, 43) within the region of the rake face (6) after the removal, such that 0° ≤ ε ≤ 70° holds. A method according to any one of the above 1 to 7, characterized by being sharpened. 9. The removal of the hard coating (2) is performed as follows: The method according to the above 8, characterized in that, with respect to the angle ε, 2°≦ε≦10°, and particularly favorably 3°≦ε≦6°, holds. 10. When partially removing the hard coating (2), The thickness of the hard coating (2) on the scoop surface (6, 46) is The thickness of the hard coating (2) increases with increasing distance from the sharpened cutting edges (14, 43), starting from the sharpened cutting edges (14, 43). The method according to 8 or 9 above, characterized by being reduced. 11. The method according to any one of 1 to 10 above, characterized in that a diamond film is deposited on the tool body (1) as a hard coating (2). 12. The hard coating (2) on the relief surfaces (5, 25, 45) is at least partially, The tool body (1) is exposed in that part, The method according to any one of the above 1 to 11, characterized in that it is completely removed. 13. The hard coating (2) on the scoop surfaces (6, 26, 46) is at least partially, The tool body (1) is exposed in that part, The method according to any one of items 1 to 12 above, characterized in that it is completely removed. 14. The method according to any one of 1 to 13 above, characterized in that the laser processing is performed by a pulsed laser beam, and the pulse duration is between 50 ns and 150 fs. 15. The method according to 14 above, characterized in that the pulse duration is between 190 fs and 10 ps. 16. The method according to 14 or 15 above, characterized in that the pulse frequency is between 100 kHz and 1,000 kHz. 17. The method according to any one of items 1 to 16 above, characterized in that the average laser output is between 4W and 40W. 18. The method according to 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 18 above, characterized in that the average laser output is between 9W and 18W. 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 of the tool body 4. The rounded circular part at the end 5. Escape 6 Scoop surface 7. Initial surface condition of the hard coating on the flank surface. 8. Surface condition of the hard coating on the relief surface after partial material removal. 9. Surface of the tool body on the relief face 10. Post-sharpened and coated cutting edges 11 Initial surface condition of the hard coating on the scooping surface 12. Surface condition of the hard coating on the scoop face after partial material removal. 12a In one option, the surface condition of the hard coating on the scoop face after partial material removal. 13 Surface of the tool body on the rake face 14 Post-sharpened and coated cutting edges 14a Post-ground and coated cutting edge in one option 15. Geometric beam axis of a laser beam 15a Geometric beam axis of a laser beam 16. The first geometric plane 17. The third geometric plane 18. The second geometric plane 19. The Fourth Geometric Plane 19a A fourth geometric plane in one of the options 20. A geometric straight line, within which a first geometric plane and a second geometric plane intersect. 23 Cutting edge of the tool body 25 Escape 26 Scoop surface 28. Surface condition of the hard coating on the flank after partial material removal. 30. First alignment of the beam axis of the laser beam. 31. Second alignment of the beam axis of the laser beam. 32. Irradiation point of the laser beam onto the surface of the hard coating. 36. The First Geometric Plane 38. The second geometric plane 40 Cutting groove 43 Cutting ridge 45 Escape 46 Scoop surface 47 Geometric beam axis of a laser beam 48. Tangent to the surface of the relief face to be machined. 49. Geometric beam axis of a laser beam 50 Tangent to the surface of the relief face to be machined 51 Tangent to the surface of the relief face to be machined

Claims

1. A method for manufacturing cutting tools, This cutting tool has a tool body (1) equipped with a hard coating (2), In a method in which the hard coating (2) is attached to the tool body (1) in at least the area of ​​the cutting edges (10, 14, 14a, 43), the flank faces (5, 25, 45), and the rake faces (6, 26, 46), The following are the steps of the method: The deposition of a hard coating (2) on the surface of the tool body (1) of the cutting tool within the region between the cutting edges (3, 23, 43), the relief faces (5, 25, 45) adjacent to the cutting edges (3, 23, 43), and the rake faces (6, 26, 46) adjacent to the cutting edges (3, 23, 43). By laser processing, the hard coating (2) is removed within the relief surface (5, 25, 45) region of the cutting edge. A first geometric plane (16, 36) on which the surface (9) of the tool body (1) extends, located below the hard coating (2) of the relief face (5, 25, 45), Regarding the angle δ between the surface (8, 28) of the hard coating (2), demarcated by the sharpened cutting edges (10, 14, 43) within the region of the relief face (5, 25, 45) after removal, and the second geometric plane (18, 38) to which the hard coating (2) extends, such that 2° ≤ δ ≤ 10° holds. Sharpening of the cutting edge that forms a rounded circular part (4) with a hard coating (2), It is characterized by the steps of the method, During laser processing, the laser beam is aligned with the geometric beam axes (15, 15a, 30, 31, 47, 49) of this laser beam. This geometric beam axis forms an angle δ or angle α+δ with the first geometric plane (16, 36), such that 1° ≤ α ≤ 10°. A method of alignment.

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

3. When removing the hard coating (2), the amount of material to be removed from the flank surfaces (5, 25, 45) is reduced as the distance from the ground cutting edges (10, 14, 14a, 43) increases. Therefore, the method according to 1 or 2, characterized in that the thickness of the hard coating (2) increases with increasing distance from the sharpened cutting edges (10, 14, 14a, 43), starting from the sharpened cutting edges (10, 14, 14a, 43).

4. The removal of material from the hard coating (2) at the relief surfaces (5, 25, 45) of the hard coating (2) is performed as follows: The method according to 1 or 2, characterized in that it starts in a portion of the relief face (5, 25, 45) spaced apart from the cutting edge (3, 23) of the tool body (1), and ends at the rake face (6, 26, 46).

5. The cut edges (10, 14, 14a, 43) having a hard coating (2) are further removed by laser processing within the area of ​​the rake face (6, 26, 46), thereby removing the hard coating (2). After removing the hard coating (2), A third geometric plane (17) extends from the surface (9) of the tool body (1) located beneath the hard coating (2) of the rake face (6, 46), With respect to the angle ε between the surface (12) of the hard coating (2), which is demarcated by the sharpened cutting edges (14, 43) within the region of the rake face (6) after removal, and the fourth plane (19) on which it extends, such that 0° ≤ ε ≤ 70° holds. The method according to 1 or 2, characterized by being sharpened.

6. Removal of the hard coating (2) is The method according to 5, characterized in that it is carried out such that 2° ≤ ε ≤ 10° holds true with respect to the angle ε.

7. When removing the hard coating (2), The amount of material to be removed from the hard coating (2) on the rake face (6, 46) is reduced with increasing distance from the ground cutting edges (10, 14, 14a, 43). Accordingly, the method according to 5, characterized in that the thickness of the hard coating (2) increases with increasing distance from the sharpened cutting edges (14, 43), starting from the sharpened cutting edges (14, 43).

8. The method according to 1 or 2, characterized in that a diamond film is deposited on the tool body (1) as a hard coating (2).

9. The hard coating (2) on the relief faces (5, 25, 45) is applied at least partially so that the tool body (1) is exposed in areas adjacent to the cutting edges (10, 14, 43). The method according to 1 or 2, characterized in that it is completely removed.

10. The hard coating (2) on the scooping surfaces (6, 26, 46) is at least partially The tool body (1) is exposed in the region adjacent to the cutting edges (10, 14, 43), The method according to 1 or 2, characterized in that it is completely removed.

11. The method according to 1 or 2, characterized in that the laser processing is performed by a pulsed laser beam, and the pulse duration is between 50 ns and 150 fs.

12. The method according to 11, characterized in that the pulse duration is between 190 fs and 10 ps.

13. The method according to 11, characterized in that the pulse frequency is between 100 kHz and 1,000 kHz.

14. The method according to 1 or 2, characterized in that the average laser output is between 4W and 40W.

15. The method according to 11, characterized in that the pulse duration is between 6 ns and 45 ns, and the pulse frequency is between 15 kHz and 200 kHz.

16. The method according to 1 or 2, characterized in that the average laser output is between 9W and 18W.

17. The method according to 1 or 2, characterized in that the beam diameter of the laser beam at the focal point is between 7 μm and 25 μm.

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