Method for laser-based processing of elongated workpieces and laser processing device for carrying out this method

Abstract

The present application relates to a method for laser-based machining of an elongated workpiece 10 and a laser machining apparatus for carrying out the method. A method and apparatus for machining an elongated workpiece 10 having a shaft 2 extending in the direction of the workpiece longitudinal axis 11 are proposed, in which at least one groove with a defined groove surface is generated in the workpiece 10 by material removal using a laser beam 17. The laser beam 17 is directed toward the surface of the workpiece 10 with its beam axis 18 and guided along a laser trajectory 15, which extends exclusively parallel to the groove profile curve. The groove profile curve corresponds to a set of intersection lines between the groove surface to be generated and a geometric plane 14, which form an angle β with the workpiece longitudinal axis 11 such that 90° ≥ β ≥ the groove inclination angle. The distance d between the groove profile curve and the laser trajectory 15 is predetermined so that the material of the workpiece 10 located in the geometric plane 14 on the side of the laser trajectory 15 facing away from the groove profile curve is completely sublimated or vaporized during the guidance of the laser beam 17 along the laser trajectory 15, depending on the power density of the laser beam 17.

Description

[Technical Field]

[0001] The present invention relates to a method for laser-based processing of elongated workpieces and to a laser processing device for carrying out the method. [Background technology]

[0002] It is known to process a workpiece by means of short, intense laser pulses: a laser beam with a high power density induces heating of material at the surface of the workpiece. The surface of the material then reaches such a high temperature that the material of the workpiece locally evaporates or sublimes. At the high power density of the laser, a plasma consisting of electrons and ions of the removed material is generated. This material removal is also called laser ablation or laser vaporization. The material can then be removed, for example, in layers, in a planar fashion. Furthermore, there is the possibility of cutting a workpiece with a continuous or pulsed laser beam, also called laser cutting or laser beam cutting. The parameters of the laser beam must be adapted to the material to be processed and the desired processing. The wavelength and average power are considered as part of the parameters of the laser beam. If the laser beam is pulsed, the pulse energy and pulse duration are also part of the parameters.

[0003] For laser processing, the laser beam and the workpiece are aligned and, if necessary, moved relative to one another in a defined manner in order to selectively remove material within a predetermined area of ​​the workpiece and to form a predetermined contour on the surface of the workpiece. In particular, the creation of cutting edges, other ridges in the workpiece, and cutting grooves are part of this purpose.

[0004] The laser processing device comprises a laser, which generates a laser beam that extends along a beam axis, where the beam axis corresponds to a geometrical straight line. The laser has a laser head that directs a laser beam with its beam axis onto the workpiece in a targeted manner and moves the laser beam over the surface of the workpiece, possibly within a predetermined contour. The workpiece is placed in an orientation and positioning device, which is also called a chuck device in a machine tool. The device includes an apparatus base, a workpiece fixing device, and a workpiece moving device. The apparatus base is arranged in a fixed position. The apparatus base can be part of a machine base of a laser processing machine. The workpiece fixture receives and securely clamps the workpiece so that the position of the workpiece relative to the workpiece fixture does not change during machining of the workpiece. The workpiece movement device serves to move the workpiece fixture relative to the device base. Since the laser head of the laser processing machine is usually arranged in a fixed position relative to the machine base, the workpiece moving device also serves to move the workpiece clamped in the workpiece clamping device relative to the laser beam generated by the laser head. Alternatively or additionally, the laser beam can be moved, which also induces a relative movement between the workpiece and the laser beam. Due to the relative movement caused by the laser processing device, the processing of the workpiece can be carried out on all surfaces of the workpiece as long as the surface of the workpiece is not covered by the workpiece fixing device. During processing, the workpiece is oriented with the surface of the workpiece toward the laser beam at various angles. The laser head can be equipped with a laser beam deflection device, which deflects the laser beam in a targeted manner using optical components and guides it onto the surface of the workpiece at high speed. The laser beam deflection device, often referred to as a laser scanner or laser scanning device, provides additional relative movement between the laser beam and the workpiece, which additional relative movement is superimposed on the movement of the workpiece, which is moved by the workpiece movement device.

[0005] For machining a workpiece, a laser beam is usually directed at the workpiece to be machined with its beam axis oriented perpendicular to the surface of the workpiece, and subsequently material is removed from the surface of the workpiece layer by layer or section by section until the workpiece has the desired shape. In that case, the workpiece can be machined in small areas, for example in the area of ​​the cutting ridge, or in larger parts of the surface, for example along the entire outer surface of the workpiece, in particular to produce an outer contour extending around the periphery of the workpiece. This also applies when elongated tools with a shaft and a head are to be produced from a cylindrical blank: drills, milling cutters or reamers, for example, are considered to be part of this type of tool. The shaft of this type of tool has a head at one end and at the opposite end, the shaft can be inserted into a tool holder of a machine and non-rotatably connected to the tool holder, so that the rotational torque of the machine can be transmitted to the tool. In the area of ​​the head, the tool is provided with one or more cutting edges and assigned cutting ridges which are used to remove chips from the material to be machined at the point of subsequent use of the tool from which it is made. These chips are guided through grooves that run on the outside of the shaft and that extend from the head in the direction opposite the head to the end of the shaft, which grooves can run parallel to the longitudinal axis of the shaft of the tool produced from the workpiece or in a spiral manner in the form of a helix. The helix is ​​characterized by its lead h and its lead angle θ, which is also referred to as the twist angle. The lead, h, corresponds to the distance the helix wraps around the longitudinal axis of the workpiece during one complete revolution. The lead angle, or helix angle, θ, is calculated from the lead, h, and the radius, r, of the helix: θ = arktan(h / (2πr)). Grooves extending parallel to the workpiece longitudinal axis have a helix angle θ of 90°. Ring-shaped grooves extending perpendicular to the workpiece longitudinal axis have a helix angle θ of 0°. The surfaces of these grooves should be smooth so that cutting chips are guided within the grooves with as little friction as possible when the tool manufactured from the workpiece is used.

[0006] During the production of grooves in the shaft of a workpiece, a particularly large amount of material needs to be removed over a relatively long distance on the workpiece surface.

[0007] From US Pat. No. 5,629,999 a method for the production of endodontic instruments using a laser is known. In this case, a highly focused Nd:YAG or CO2 laser beam is directed radially or sekantally relative to the surface of the workpiece, and the surface is scanned linearly, causing the laser to create a spiral groove in the surface of the tool workpiece.

[0008] Furthermore, from DE 10 200 01 199 A1 an apparatus and a method for the production of tools by laser machining are known, in which grooves and ridges are produced in a semi-finished product, in which laser beam pulses of a laser are directed by a deflection device onto the semi-finished product at predetermined irradiation positions in a pulse plane. A positioning device performs the relative movement between the workpiece and the pulse surface. To create the groove, the laser beam is directed essentially radially onto the elongated workpiece. Layer by layer, material is removed until the groove has a predetermined depth.

[0009] The methods known from Patent Documents 1 and 2 have the disadvantage that the laser beam is essentially oriented perpendicular to the groove surface to be oriented, and the groove surface to be oriented therefore has a high surface roughness.

[0010] However, from patent document 3, a method is known for the production of cutting grooves in rod-shaped tools, in which grooves with smooth surfaces are produced in the surface of the tool, but this method has the disadvantage of a low removal rate. In contrast to the methods of US Pat. No. 5,629,999 and US Pat. No. 5,629,999, in the material removal according to US Pat. No. 5,629,999 the laser beam is essentially oriented tangentially to the groove surface to be produced. However, by using a deflection device, the laser beam is guided along a pulse trajectory that fills a pulse surface, where the pulse surface corresponds to the cross section of the material portion to be removed in the groove. This beam guidance is time-consuming. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] DE 199 01 777 A [Patent Document 2] DE 10 2010 011 508A [Patent Document 3] DE 10 2014 109 613 A Summary of the Invention [Problem to be solved by the invention]

[0012] The problem underlying the present invention is to provide a method and a laser processing device for laser-based processing of elongated workpieces, with which at least one groove with a predetermined groove surface is generated by material removal in the workpiece with a laser beam, and which groove extends along at least a portion of the outer surface of the shaft of the workpiece, In this case, material removal takes place with a high removal rate, and the grooves produced in this case have a smooth surface with low surface roughness. [Means for solving the problem]

[0013] This problem is solved by a method having the features of claim 1 and by a laser processing device having the features of claim 13. The method according to claim 1 comprises: The workpiece is placed in a workpiece fixture of the laser processing machine, and a first end of a shaft of the workpiece is received in the workpiece fixture of the laser processing machine; and the material is removed with a laser beam starting from a second end of the shaft opposite the first end in a direction towards the first end or in a direction opposite thereto, the laser beam having a specific orientation and being guided along a specific laser trajectory; It is characterized by: The first end of the shaft is hereinafter referred to as the first shaft end, and the second end of the shaft is hereinafter referred to as the second shaft end. In this case, a groove is created that extends along at least a portion of the outer surface of the shaft between a first groove end and a second groove end, the first groove end being offset relative to the second groove end in an axial direction relative to the workpiece longitudinal axis, the first groove end being oriented toward the first axial end, whereas the second groove end being oriented toward the second axial end. For material removal, the laser beam is directed with its beam axis onto the surface of the workpiece and guided along a laser trajectory that, throughout the entire material removal, runs exclusively parallel to the groove profile curve, which corresponds to the set of intersections between the groove surface to be generated and a geometric plane. The geometric plane is a conceptual auxiliary means by which the laser trajectory is described. The geometric plane is always located at the point of impact of the laser beam on the workpiece, at the position where material is removed in the workpiece with the laser beam. Thus, to generate a groove between the first groove end and the second groove end, the geometric plane is moved in the longitudinal direction of the workpiece during progressive material removal. In this case, the geometric plane is aligned to the longitudinal axis of the workpiece under an angle β, with the following relation being true for the angle β: 90°≧β≧the inclination angle of the groove. The workpiece longitudinal axis is then a geometric straight line that extends through the workpiece in the longitudinal direction of the elongated workpiece. The geometric plane likewise extends through the workpiece. An intersection of the workpiece longitudinal axis and the geometric plane is located within the workpiece, and the geometric plane, along with the groove profile curve and laser trajectory, is moved axially relative to the workpiece longitudinal axis during material removal between the first groove end and the second groove end. During all material removal between the first and second groove ends, the distance d between the groove profile curve and the laser trajectory is predetermined and remains unchanged. The distance d between the groove profile curve and the laser trajectory is predetermined so that, in the geometric plane, the material of the workpiece located on the side of the laser trajectory facing away from the groove profile curve is completely sublimated or vaporized during the guidance of the laser beam along the laser trajectory, depending on the power density of the laser beam. The distance d between the laser trajectory and the groove profile curve therefore depends on the power density of the laser. The laser produces short, high-energy laser pulses that result in a high energy input in the area where the laser beam irradiates the workpiece surface, thereby intensely heating this area and causing the workpiece material in this area to sublimate or evaporate. However, since the laser pulse is very short, the heat diffuses negligibly little within the workpiece, and the heated area is therefore locally limited, which is advantageous because in this way undesired deformation of the workpiece under the action of heat can be prevented. The higher the power density, and therefore the energy input into the workpiece surface, the more material can be removed within a given time interval, in which case the divergence of the laser beam at the point of irradiation on the workpiece surface and / or the material of the workpiece also play a role. [Effects of the Invention]

[0014] The geometric plane is oriented relative to the workpiece longitudinal axis so that the laser beam can be guided along the laser trajectory without impinging on the workpiece in an undesired manner. In particular, the laser beam is permitted to irradiate the surface of the workpiece only in the area where material removal is to occur. Interaction of the laser beam with other areas of the workpiece should be avoided. The angle β between the geometric plane and the workpiece longitudinal axis is adjusted so that the laser trajectory, as a set of intersection lines between the geometric plane and the groove surface to be generated, allows collision-free guidance of the laser beam within a predetermined angular range between the groove surface to be generated and the beam axis of the laser beam. In that case, the angle β is less than or equal to 90° and greater than or equal to the inclination angle of the grooves. If the grooves run parallel to the longitudinal axis of the workpiece and therefore have an inclination angle of 90°, the angle β always corresponds to 90°.

[0015] The laser trajectory is predetermined with respect to the distance d of this laser trajectory relative to the groove profile curve such that all material of the workpiece located outside the laser trajectory relative to the workpiece longitudinal axis is removed during guidance of the laser beam along the laser trajectory. If the workpiece has a small cross section and / or the groove is not deep, it may be sufficient that the laser trajectory is defined parallel to the groove profile curve and that, when guiding the laser beam, along this one laser trajectory all material outside the groove profile curve is already removed, and thus the groove surface is generated within this area. In this situation, it is sufficient if the geometric plane, the groove profile curve and the laser trajectory 26 are moved once from the first groove end to the second groove end or vice versa, with a predetermined distance d, and material is removed by the laser to form the groove. However, if the workpiece has a large diameter and / or deep grooves, material must be removed layer by layer. During removal of the first layer, the laser trajectory is located at a first position near the outer surface of the workpiece that has not yet been machined. In this first step, the laser trajectory has a first distance d1 relative to the groove profile curve, and material removal between the first groove end and the second groove end occurs with this first distance d1 during this first step. When the first layer of material extending between the first and second groove ends is being removed, the laser trajectory is moved in a second step in the direction of the groove profile curve, so that the laser trajectory 26 is located at a second position. In this second step, the laser trajectory has a second spacing d2 relative to the groove profile curve, where the second spacing d2 is smaller than the first spacing d1. The material removal between the first and second groove ends is carried out during this second step with this second distance d2. Thus, many layers are removed until the groove is created. For this purpose, the laser trajectory is moved, very often stepwise, in the direction of the groove profile curve after each layer removal until all material outside the groove profile curve to be created has been removed.

[0016] During the removal of one layer, which extends from the first groove end to the second groove end, the distance d between the groove profile curve and the laser trajectory is not changed. The distance d is changed only when one layer has been removed from the first groove end to the second groove end and not enough material has been removed to form the preset groove, and subsequently a further layer of material is removed, this layer extending from the first groove end to the second groove end.

[0017] The laser beam is guided along the laser path so that its beam axis forms an angle δ with the tangent of the groove surface to be generated at the point of impact on the workpiece, where 1°≦δ≦10°. The beam axis is inclined away from the longitudinal axis of the workpiece. In the tangential alignment of the beam axis, the angle δ=0°. The beam axis of the laser beam therefore does not extend tangentially to the groove surface at the irradiation location, but rather is slightly inclined with respect to this tangent. By orienting the laser beam with an inclination relative to the workpiece surface, and therefore to the geometric plane, at which material removal is performed, it is possible to prevent evaporated or sublimated material from being deposited on the groove surface to be created, and to prevent this groove surface of the workpiece from being burned in an undesirable manner. The part on which the laser beam irradiates is removed during material removal. The groove surface thus produced has a very good surface quality with little roughness after laser processing. This is what distinguishes the method of the present application from the methods according to Patent Documents 1 and 2.

[0018] When the laser beam removes material, exclusively parallel to the groove profile curve and with a fixed predetermined distance d relative to this groove profile curve, wherein this distance d is predetermined and adjustable as a function of the power density; Due to the laser being guided along the trajectory, this material removal takes place within a significantly shorter time interval, and therefore high removal rates are achieved. In contrast to Patent Document 3, the laser beam is not guided in two dimensions across the entire cross section of the material portion to be removed, but rather only along a laser trajectory extending in one dimension. In this case, it is utilized that material is removed not only in the immediate vicinity of the irradiation position of the laser track, but also outside the laser track, for this purpose, all material of the workpiece is converted into a gaseous condensed state outside the laser track, without the laser beam being guided over the entire region to be removed over a large area. A laser trajectory parallel to the groove profile curve does not define any two-dimensional plane in which the laser beam irradiates the surface and material is removed only at the irradiated locations. The laser trajectory parallel to the groove profile curve does not define any two-dimensional surface, which surface is moved relative to the workpiece by the relative movement between the laser beam and the workpiece in order to remove material in a planar manner. The removal rate is also significantly higher if, in the method according to the invention, material is removed in several layers with different spacings d1, d2, etc.

[0019] The laser beam has a diameter that is adjusted and predetermined by the laser optics. To achieve a particularly high energy density at the point of irradiation of the laser beam relative to the surface of the workpiece, the focus of the laser beam can be adjusted so that this focus is located on the workpiece surface. The beam axis extends through the center of the laser beam. The laser trajectory is defined by the movement of the beam axis. This means that the laser beam extends laterally relative to the laser trajectory at the position of irradiation relative to the workpiece surface, and material removal occurs not only directly on the laser trajectory but also alongside the laser trajectory within a portion determined by the diameter of the laser beam at the position of irradiation relative to the workpiece surface; means. To avoid material removal deeper into the workpiece than the predetermined groove surface, the laser trajectory always extends parallel to the groove profile curve and at a minimum distance from the groove profile curve that is predetermined by the diameter of the laser beam.

[0020] According to an advantageous configuration of the invention, material is removed in multiple layers. the laser beam is guided along a first laser trajectory parallel to the groove profile curve throughout removal of the first layer extending from the first groove end to the second groove end; The first laser trajectory has a first spacing d1 relative to the groove profile curve during removal of the first layer. Subsequently, the laser beam is guided along a second laser trajectory parallel to the groove profile curve during removal of the second layer extending from the first groove end to the second groove end; This second laser trajectory has a second spacing d2 relative to the groove profile curve during removal of the second layer. In that case, the second distance d2 is smaller than the first distance d1.

[0021] According to a further advantageous embodiment of the invention, until the groove surface is generated, Within further layers, material is removed along further laser trajectories at decreasing intervals relative to the groove profile curve.

[0022] According to a further advantageous embodiment of the invention, the material removal is carried out by means of a pulsed laser beam (17).

[0023] According to a further advantageous embodiment of the invention, the laser pulses have a maximum pulse duration of 10 ps. The pulse duration is then 10 ps or shorter. For example, femtosecond lasers are considered part of the lasers with ultrashort laser pulses of this type.

[0024] According to a further advantageous configuration of the invention, the laser beam is guided along the laser path multiple times, in which case the laser beam is moved along the laser path first in one direction and then in the opposite direction. The laser beam can be guided along the same laser trajectory once or multiple times for material removal, depending on whether material removal has already occurred in a given perimeter after one guidance along the laser trajectory. For multiple steering of the laser beam along the laser trajectory, the direction in which the laser beam is steered along the laser trajectory can be maintained or changed.

[0025] The groove is generated starting from the first groove end or starting from the second groove end, and by progressive material removal the geometric plane in which the groove profile curve extends is advanced from the first groove end to the second groove end or from the second groove end to the first groove end. The second groove end is typically located adjacent to a second axial end of the shaft, which second axial end includes the head of a tool to be made from the workpiece. The first groove end is typically located on the shaft at a distance from the first end of the shaft. No grooves are typically located in the portion of the shaft provided for fixing a tool to be made from the workpiece in a tool holder of the machine.

[0026] According to a further advantageous embodiment of the invention, after the guidance of the laser beam from one end of the laser path to the other end thereof along a laser path parallel to the groove profile curve, the workpiece is moved in the direction of the workpiece longitudinal axis by means of the workpiece moving device, and the workpiece is then advanced relative to the laser beam. This serves for progressive laser processing of the workpiece in the direction of the workpiece longitudinal axis.

[0027] According to a further advantageous embodiment of the invention, the workpiece is rotated about its longitudinal axis by the workpiece movement device during laser processing. This rotation assists in guiding the laser beam once or multiple times along a laser trajectory parallel to the groove profile curve from one end of the laser trajectory to the other end.

[0028] According to a further advantageous embodiment of the invention, the distance d between the groove profile curve and the laser trajectory corresponds to half the diameter of the laser beam at the location of this laser beam on the workpiece surface. Optionally, the distance d between the groove profile curve and the laser trajectory is larger as well.

[0029] According to a further advantageous configuration of the invention, a second movement of the laser beam is superimposed on the first movement of the laser beam along the laser trajectory. This second movement is generated by means of an optical laser beam deflection device, such as a laser scanner, in which case the speed of the second movement is greater than the speed of the first movement. The second movement serves to move the laser beam along a laser trajectory parallel to the groove profile curve, in an open or closed curve, whereby the diameter of the material removal along the laser trajectory is increased in relation to the diameter of the laser beam.

[0030] According to a further advantageous embodiment of the invention, the second movement is performed along a curve having a diameter m, and the distance d between the groove profile curve and the laser trajectory is equal to or greater than half the diameter m of the curve of this second movement.

[0031] According to a further advantageous embodiment of the invention, the method allows for the production of cutting tools, such as drills, milling cutters or reamers.

[0032] The laser processing apparatus according to the present invention comprises: a workpiece fixture that receives and fixes the workpiece; a workpiece moving device that moves the workpiece fixing device relative to the device base; It is equipped with a laser, a laser beam of the laser is directed with a geometric beam axis of the laser beam onto a workpiece accommodated in a workpiece fixture; At that time, the laser processing equipment for orienting a workpiece disposed within the workpiece fixture relative to the laser beam and for moving the laser beam relative to the workpiece; It is formed. Furthermore, the laser processing apparatus has a control device, which controls the laser processing apparatus according to any one of claims 1 to 12.

[0033] According to a further advantageous configuration of the invention, the laser processing apparatus comprises a laser beam deflection device which generates a second movement of the laser beam, which second movement of the laser beam is superimposed on the first movement of the laser beam along a laser trajectory parallel to the groove profile curve.

[0034] Further advantages and advantageous embodiments of the present invention can be seen from the following description, drawings and claims.

[0035] In the drawing, an embodiment of the subject matter of the invention is shown. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a perspective view of a tool produced from a workpiece. [Figure 2] 2 is a view of the tool according to FIG. 1 in a top view of the head. [Figure 3] FIG. 3 is a view of a cylindrical workpiece from which the tool according to FIGS. 1 and 2 is produced. [Figure 4] 4 is a perspective view of the workpiece according to FIG. 3 after the creation of the two grooves. [Figure 5] 5 is a view of the workpiece according to FIG. 4 in a view from above the second end. [Figure 6] 1 is a view of a portion of a workpiece at the start of the implementation of the method; [Figure 7] FIG. 7 is a top view of the workpiece according to FIG. 6. [Figure 8] 7 is a top view of the workpiece according to FIG. 6 after material removal in the first layer. [Figure 9] 9 is a perspective view of a second axial end of the workpiece after material removal of the first layer according to FIG. 8. FIG. [Figure 10] 10 is a view of a second axial end of the workpiece according to FIG. 9 with a laser trajectory for material removal of the second layer. [Figure 11] 11 is a perspective view of a second axial end of the workpiece after material removal of the second layer in accordance with FIGS. 8 and 10; FIG. [Figure 12] 12 is a view of a portion of the workpiece according to FIGS. 6 to 11, in which a portion of the first layer within the groove has been removed within the groove. FIG. [Figure 13a] 12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 13b]12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 13c] 12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 13d] 12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 13e] 12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 13f] 12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 13g] 12A-12D are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the first layer in different steps. [Figure 14a] 12A to 12C are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the second layer in different steps. [Figure 14b] 12A to 12C are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the second layer in different steps. [Figure 14c] 12A to 12C are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the second layer in different steps. [Figure 14d] 12A to 12C are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the second layer in different steps. [Figure 14e] 12A to 12C are views of a portion of a workpiece according to FIGS. 6 to 11: namely, a view of the material removal of the second layer in different steps. [Figure 15] 1 is a diagram of the guidance of a laser beam in a first movement along the laser trajectory and within a superimposed second movement. [Figure 16] FIG. 10 is a diagram of a first example of a curve of the second movement. [Figure 17] FIG. 10 is a diagram of a second example of a second displacement curve. [Figure 18] 1 is a perspective view of a workpiece having a geometric plane that forms a 70° angle with the workpiece longitudinal axis. [Figure 19] 17 is a view of the workpiece according to FIG. 16 with material removal in the groove. [Figure 20] FIG. 1 is a diagram of a laser processing device. DETAILED DESCRIPTION OF THE INVENTION

[0037] 1 to 19, an embodiment of a workpiece to be processed with the method according to the invention is shown at various stages of processing. A laser processing apparatus 50 for carrying out this method is shown in FIG. Figure 1 shows a tool 1 made from a workpiece. What is being treated here is a drill having an elongated shaft 2 and a head 3. The head 3 is provided with two cutting edges 4. The shaft 2 has a first shank 5, with which the workpiece 10 belonging to the tool 1 is inserted and clamped in a workpiece clamping device 51 of the laser processing machine 50. The first shank 5 is further used to position the tool at its subsequent place of use, for example in a tool holder of the machine, not shown in the figures. At a second axial end 6 of the shaft 2, opposite the first axial end 5, a head 3 is located. Starting from the head 3 at the second axial end 6, two grooves 7 extend in a helical, thread-like manner on the outer surface of the shaft 2, with one groove 7 assigned to each of the two cutting ridges 4. Each groove 7 has a first groove end 8 directed towards the first axial end 5 of the shaft and a second groove end 9 directed towards the second axial end 6 of the shaft, with the second groove end 9 being located directly in the head 3 and in close proximity to the cutting ridge 4. The first groove end 8 is spaced apart in the axial direction from the first shaft end 5. In particular, the groove does not extend all the way to the first shaft end 5, because a portion of the shaft 2 at the first shaft end 5 is provided for fixing the tool 1 in a tool holder of the machine.

[0038] The grooves 7 are produced by the method according to the invention in the outer surface of a workpiece 10 shown in Figure 3. At the start of the method, the workpiece 10 is a blank having the shape of a cylinder, as shown in Figure 3. This elongated workpiece 10 essentially consists of a shaft 2, since the head of the workpiece with the cutting edges shown in Figures 1 and 2 has not yet been produced in the workpiece 10. The shaft 2 is elongated. It extends along the workpiece longitudinal axis 11. 3, groove profile curves 12 have already been drawn on the end face of the workpiece 10 at the second axial end 6, which groove profile curves mark the groove surfaces of the grooves 7 to be produced at this end face. The surface of the workpiece 10 at the end face of the second axial end 6 forms a geometric plane, which is oriented perpendicular to the workpiece longitudinal axis 11. The groove profile curve 12 forms the set of intersections between this geometric plane and the groove surface of the groove to be produced, which is also shown in FIG.

[0039] 4 and 5 show the workpiece 10 after completion of the method according to the invention. Both grooves 7 have been produced in the outer surface of the shaft 2. The grooves extend from a first groove end 8 of the groove to a second groove end 9 of the groove in the outer surface of the shaft 2. 1 and 2, only the cutting ridges 4 are missing. Each of these grooves 7 has a groove surface 13. This groove surface 13 is curved in multiple directions. On the one hand, each of these grooves forms a recess arched inwards in the direction of the workpiece longitudinal axis 11 relative to the remaining surface of the shaft 2, which essentially corresponds to a cylindrical outer casing. On the other hand, the groove surface 13 is curved because the grooves 7 have a helical thread-like progression relative to the workpiece longitudinal axis 11. It is possible for the shape of the grooves 7 to be constant from the first groove end 8 to the second groove end 9. This is the case in the embodiment shown in the figures. Alternatively, the shape can change from the first groove end 8 to the second groove end 9. Thus, for example, the width or depth of the groove can increase or decrease from the second groove end to the first groove end. The groove profile curve 12 visible in FIG. 3 at the end side of the workpiece 10 corresponds in FIGS. 4 and 5 to the ridge between the end side at the second axial end 6 and the groove surface 13 of both grooves 7 .

[0040] Figure 6 shows the start of material removal at the second axial end 6 of the shaft 2 of the workpiece 10, where the head 3 will be located in the finished tool. The end side of the workpiece 10 at the second axial end 6 is a flat surface, which is oriented perpendicular to the workpiece longitudinal axis 11, before the start of material removal. This flat surface corresponds to a geometric plane 14 at the start of material removal, which geometric plane is perpendicular to the workpiece longitudinal axis 11. The groove profile curves illustrated in FIG. 6 are not identified in this FIG. 6 with the reference numeral 12 . Figure 3 shows a groove profile curve with the reference numeral 12. This groove profile curve 12 corresponds to the set of intersection lines between a geometric plane 14 and a groove surface 13 to be generated according to this figure 3. Figure 6 further shows a laser trajectory 15 parallel to the groove profile curve 12.

[0041] In the illustrated embodiment, the grooves 7 do not change shape from the first groove end to the second groove end, so the groove profile curve 12 is the same in shape for each geometric plane perpendicular to the workpiece longitudinal axis 11. As long as the intersection point is located between the first and second groove ends, this is true regardless of where the geometric plane intersects the workpiece longitudinal axis 11. Since the groove 7 has a thread-like progression, from plane to plane, only the position of the groove profile curve changes angularly.

[0042] 7 to 11 show how the laser trajectories 15, 16 are defined relative to the groove profile curve 12 in the workpiece 10. Because the workpiece 10 has a certain diameter, the material in the groove needs to be removed in two layers. Figures 7 and 9 show the position of the laser trajectory 15 during material removal of the first layer, which is referred to as the first laser trajectory 15. Figures 8, 10 and 11 show the laser trajectory 16 during material removal of the second layer, which is referred to as the second laser trajectory 16.

[0043] A groove profile curve 12 is illustrated in Figures 7, 8 and 11. To create a groove surface 13, material needs to be removed up to this groove profile curve 12. 7 and 9, a first laser trajectory 15 is defined, which has a first distance d1 from the groove profile curve 12. When the laser beam 17 is guided along this first laser trajectory 15 with its beam axis 18 as shown in FIG. 12, material lying outside the first intermediate profile curve 19 is removed. FIG. 8 shows the workpiece in a top view after the laser beam has been guided along the first laser trajectory 15 and material has been removed outside the first intermediate profile curve 19. 9 shows in perspective view the second axial end of the shaft 2 after material has been removed up to the first intermediate profile curve 19 and material removal has continued from the second axial end 6 in the direction towards the first axial end 5. An intermediate groove 20 is then created, the groove surface 21 of which is parallel to the groove surface 13 of the groove 7 to be created. The intermediate groove 20 has a smaller depth than the final groove 7. In the illustrations according to FIGS. 7 and 8, the intermediate profile curve 19 coincides with the intermediate groove 20. For material removal of the second layer, a second laser trajectory 16 is defined, which has a distance d2 from the groove profile curve 12, d2 being smaller than d1. When the laser beam is guided along this second laser trajectory 16 with its beam axis, all material located between the first intermediate profile curve 19 and the groove profile curve 12 is removed. When material removal continues from the second shank end 6 in the direction towards the first shank end 5 and a groove 7 is created between the first groove end 8 and the second groove end 9, a groove surface 13 is created during this material removal. FIG. 11 shows the second axial end 6 of the shaft 2 in a perspective view after removal of material down to the groove surface 13 .

[0044] 12 shows the workpiece 10 during material removal with the laser beam 17 and the beam axis 18. According to this illustration, starting from the second end 6 of the shaft 2, a portion of the material has already been removed up to a distance a from this second end 6 of the shaft 2. A first intermediate groove 20 is then generated across the distance a. For this purpose, the geometric plane 14 is advanced along the workpiece longitudinal axis 11, starting from the second axial end 6 of the shaft 2 in the direction of the first axial end 5. 12, the geometric plane 14 is perpendicular to the workpiece longitudinal axis 11. The laser beam 17 is oriented such that, during material removal, its beam axis 18 forms an angle of between 1° and 10° with the groove surface 13 of the groove 7 or the groove surface 21 of the intermediate groove 20 to be produced. In the present case, this means that the beam axis 18 is neither parallel to the workpiece longitudinal axis 11 nor perpendicular to the geometric plane 14. The beam axis 18 is a geometric straight line. It forms an angle of between 1° and 10° with the workpiece longitudinal axis and an angle α of between 80° and 89° with the geometric plane 14. The angle α then corresponds to the difference between 90° and the angle δ. The beam axis 18 is then oriented relative to the geometric plane 14 such that it is inclined away from the workpiece longitudinal axis 11. The laser beam 17 and the alignment of its beam axis 18 serve to achieve a particularly good surface quality of the groove surface 13. The groove surface 13 is smooth and has a low roughness, so that further processing of the groove surface 13 is unnecessary.

[0045] In order to guide the laser beam 17 with its beam axis 18 along the first laser trajectory 15, the workpiece 10 is rotated about the workpiece longitudinal axis 11. This rotation is illustrated in Figure 12 by the arrow 22. The angle by which the workpiece 10 is then rotated is predetermined by the width of the groove 7 or intermediate groove 20.

[0046] In Figures 13a to 13g, the material removal of the first layer according to the first laser trajectory 15 is illustrated at different processing stages, with a distance d1 between the first laser trajectory 15 and the groove profile curve 12. The groove profile curve 12 and the distance d1 are not depicted in Figures 13a to 13g, and are given by Figures 7, 8 and 11. FIG. 13 a shows the workpiece 10 at the start of material removal with the laser beam 17 directed onto the end side of the second axial end 6 of the workpiece 10 and the first laser trajectory 15 . Figure 13b shows the workpiece 10 after some of the material has already been removed and a portion of the intermediate groove 20 has been created, extending in the direction from the second axial end 6 to the first axial end 5. FIG. 13 c shows this processing step with the laser beam 17 and the first laser trajectory 15 . 13d, e, and f show the workpiece 10 after further portions of the first layer material have been removed. 13g shows the portion of workpiece 10 after the first layer has been removed and an intermediate groove 20 has been created, the intermediate groove 20 extending between first groove end 8 and second groove end 9. Intermediate groove 20 has a groove surface 21.

[0047] In Figures 14a to 14e, the material removal of the second layer according to the second laser trajectory 16 is illustrated at different processing stages, with a spacing d2 between the second laser trajectory 16 and the groove profile curve 12. The groove profile curve 12 and spacing d2 are not depicted in Figures 14a to 14e, and are given by Figures 7, 8, and 11. The workpiece 10 illustrated in FIG. 14a corresponds to the workpiece 10 in FIG. 13g. FIG. 14 a additionally shows a laser beam 17 and a second laser trajectory 16 . 14b through 14c show the workpiece 10 after a portion of the second layer of material has been removed. 14e shows the portion of workpiece 10 after the second layer has been removed and groove 7 has been created, in which groove 7 extends between first groove end 8 and second groove end 9. Groove 7 has a groove surface 13.

[0048] FIG. 15 shows the effect that the use of a laser beam deflector 57 illustrated in FIG. 20 has. The laser beam deflection device serves for a second movement of the laser beam 17 in its beam axis 18, the second movement being superimposed on a first movement of the laser beam 17 in its beam axis 18 along a first laser trajectory 15 parallel to the groove profile curve 12. The second movement serves for a loop-like guidance of the laser beam 17 in its beam axis 18. 16 and 17, two possible curves 23 and 24 are shown by way of example, along which the laser beam 17 with its beam axis 18 can be guided in the second movement. Both curves are closed, with the curve 23 being irregularly shaped and the curve 24 embodying a circle. It is possible that both movements are assigned a diameter m. The speed at which the second movement is performed is greater than the speed of the first movement. The second movement of the laser beam is the material removal along the first laser trajectory 15, 16 is not carried out in an area predetermined relative to the workpiece surface by the diameter of this laser beam at the irradiation position, but rather in an area predetermined by the diameter m of the second movement curve 23, 24; This has the effect of:

[0049] 18 and 19 show one embodiment of the method according to the invention in which the geometric plane 25 is not oriented perpendicular to the workpiece longitudinal axis 11, but rather is oriented under an angle β of 70°. In this case too, the laser trajectory 26 extends parallel to a groove profile curve 27 in a geometric plane 25, which groove profile curve is given as the set of intersections between the groove surface 28 of the groove 7 to be generated and the geometric plane 25. Apart from the different angle between the workpiece longitudinal axis 11 and the geometric plane 25, the method according to Figures 18 and 19 corresponds to the method of Figures 3 to 17.

[0050] 20 shows a laser processing apparatus 50 for carrying out this method. The laser processing apparatus 50 includes a workpiece fixing device 51 for accommodating and fixing the workpiece 10, a workpiece moving device 53 that moves the workpiece 10 placed in the fixing device relative to the device base part 55; a laser 56 generating a laser beam 17; and and a laser beam deflector 57 for guiding the laser beam 17. The workpiece moving device 53 has, in the present case under consideration, three linear axes X, Y, Z and two rotational axes B and C. The rotation axis C then serves for the rotation of the workpiece 10 arranged in the workpiece fixture 51 about a geometric workpiece rotation axis extending through the workpiece 10. Advantageously, the workpiece 10 is arranged in the workpiece fixture 51 such that the workpiece rotation axis coincides with the workpiece longitudinal axis 11. The laser beam deflection device 57 moves and guides the laser beam 17 in three different directions in space, whereby the laser beam 17 is moved relative to the workpiece 10 along a laser path not shown in Fig. 18. For this purpose, the laser beam deflection device 57 comprises a number of mirrors, which can redirect the laser beam in a targeted manner. Furthermore, the laser beam deflection device comprises at least one lens, which focuses the laser beam onto the surface of the workpiece 10. These mirrors and lenses are not shown in the figures. To carry out the method for machining the workpiece, the control device 58 controls the clamping device 51, the workpiece moving device 53, the laser 56 and the laser beam deflection device 57.

[0051] All features may be essential to the invention both individually as well as in any suitable combination with one another. The present application relates to the invention described in the claims, but may also include the following as other aspects. 1. Using the laser processing device (50), 1. A method for laser-based machining of an elongated workpiece (10) having a shaft (2) extending in the direction of a workpiece longitudinal axis (11), comprising: By removing material using a laser beam (17), At least one groove (7) having a defined groove surface (13, 28) is created in the shaft (2), and the groove (7) extends between a first groove end (8) and a second groove end (9) along at least a portion of the outer surface of the shaft (2); the first groove end (8) is offset axially relative to the workpiece longitudinal axis (11) relative to the second groove end (9); The laser processing equipment - a workpiece fixing device (51) for receiving and fixing the workpiece (10); a workpiece moving device (53) that moves the workpiece fixing device (51) relative to the device base part (55); - equipped with a laser (56), A laser beam (17) of the laser is directed with a geometric beam axis (18) of the laser beam onto a workpiece (10) accommodated in a workpiece fixture (51), A laser processing device (50) a workpiece (10) positioned within the workpiece fixture (51) configured to orient the workpiece (10) relative to the laser beam (17) and to move the laser beam (17) relative to the workpiece (10); The method comprising the following method steps: Arranging the workpiece (10) in the workpiece fixture (51) such that the first axial end (5) of the shaft (2) is received in the workpiece fixture (51); Removal of material with a laser beam (17) from a second axial end (6) of the shaft (2) opposite the first axial end (5) in the direction towards the first axial end (5) or in the opposite direction; In that case, a groove (7) is formed between a first groove end (8) directed towards the first axial end (5) and a second groove end (9) directed towards the second axial end (6), a laser beam (17) is directed with its beam axis (18) onto the surface of the workpiece (10) and guided along a laser trajectory (15, 16, 26); the laser trajectories (15, 16, 26) extend exclusively parallel to the groove profile curves (12, 27); the groove profile curve (12, 27) corresponds to a set of intersection lines between the groove surface (13, 28) to be generated and the geometric plane (14, 25), the set of intersection lines forming an angle β with the workpiece longitudinal axis (11) such that 90° ≥ β ≥ the groove inclination angle; and The geometric plane (14, 25) together with the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) moved axially relative to the workpiece longitudinal axis (11) during material removal between the first groove end (8) and the second groove end (9); the distance d between the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) is predetermined and remains constant throughout all material removal between the first groove end (8) and the second groove end (9); the distance d is predetermined so that the material of the workpiece (10) located on the side of the laser trajectory (15, 16, 26) facing away from the groove profile curve (12, 27) in the geometrical plane (14, 25) is completely sublimated or vaporized during the guidance of the laser beam (17) along the laser trajectory (15, 16, 26) depending on the power density of the laser beam (17); The laser beam (17) is oriented with a beam axis (18) of the laser beam such that, at the point of incidence on the workpiece (10), the beam axis (18) forms an angle δ with the tangent of the groove surface to be produced, where 1°≦δ≦10°. Guided along the laser trajectory (15, 16, 26), A method characterized by method steps. 2. Material is removed in multiple layers; a laser beam (17) is guided along a first laser trajectory (15) parallel to the groove profile curve (12, 27) during removal of the first layer extending from the first groove end (8) to the second groove end (9); the first laser trajectory has a first spacing d1 relative to the groove profile curve (12, 27) during the removal of the first layer; and a laser beam (17) is guided along a second laser trajectory (16) parallel to the groove profile curve (12, 27) during removal of the second layer extending from the first groove end (8) to the second groove end (9); the second laser trajectory has a second spacing d2 relative to the groove profile curve (12, 27) during the removal of the second layer, and The second distance d2 is smaller than the first distance d1. 2. The method according to claim 1, wherein 3. Until the groove surface (13, 28) is generated. 3. The method according to claim 2, characterized in that in further layers material is removed along further laser trajectories parallel to the groove profile curve (12, 27) and at decreasing intervals relative to the groove profile curve (12, 27). 4. Material removal is performed by a pulsed laser beam (17); 4. The method according to any one of 1 to 3 above, characterized in that 5. The method according to claim 4, wherein the laser pulse has a pulse duration of 10 ps or less. 6. The laser beam (17) is guided multiple times along laser trajectories (15, 16, 26) parallel to the groove profile curve (12, 27); and the laser beam (17) is then moved along the laser trajectory (15, 16, 26) first in one direction and then in the opposite direction, 6. The method according to any one of 1 to 5 above, characterized in that: 7. After guiding the laser beam (17) along a laser trajectory (15, 16, 26) parallel to the groove profile curve (12, 27) from one end of the laser trajectory (15, 16) to the other end of the laser trajectory (15, 16), The workpiece (10) is moved in the direction of the workpiece longitudinal axis (11) by a workpiece moving device (53), and in so doing, the workpiece (10) is advanced relative to the laser beam (17); 7. The method according to any one of 1 to 6 above, 8. The workpiece (10) is rotated about the workpiece longitudinal axis (11) during laser processing by the workpiece moving device (53). 8. The method according to any one of 1 to 7 above, characterized in that 9. The distance d between the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) is At the location of this laser beam on the workpiece surface, the diameter is equal to or greater than half the diameter of the laser beam (17); 9. The method according to any one of 1 to 8 above, characterized in that 10. A second movement of the laser beam (17) is superimposed on a first movement of the laser beam (17) along a laser trajectory (15, 16, 26) parallel to the groove profile curve (12, 27), and said second movement being generated using a laser beam deflection device (57); 10. The method according to any one of claims 1 to 9, characterized in that: 11. A second movement is made along the laser beam deflection curve (23, 24), the laser beam deflection curve having a diameter m; and the distance d between the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) parallel to the groove profile curve (12, 27) is equal to or greater than half the diameter m of the laser beam deflection curve (23, 24) of this second movement; 11. The method according to claim 10, characterized in that: 12. A method according to any one of claims 1 to 11, characterized in that a cutting tool is produced. 13. A laser processing device, which is a workpiece fixing device (51) for receiving and fixing the workpiece (10); a workpiece moving device (53) that moves the workpiece fixing device (51) relative to the device base part (55); a laser (56); A laser beam (17) of the laser is directed with a geometric beam axis (18) of the laser beam onto a workpiece (10) accommodated in a workpiece fixture (51), A laser processing device (50) To orient a workpiece (10) disposed within a workpiece fixture (51) relative to a laser beam (17), and to move the laser beam (17) relative to the workpiece (10); and A laser processing apparatus configured to remove material from a workpiece (10) with a laser beam (17), The laser processing device (50) is provided with a control device (58), and the control device controls the laser processing device (50) according to any one of 1 to 12 above. A laser processing device characterized by: 14. The laser processing device according to claim 13, characterized in that the laser processing device is equipped with a laser beam deflector (57). [Explanation of symbols]

[0052] 1 tool 2 shafts 3 head 4 Cutting ridge 5 First shaft end 6 Second shaft end 7 Groove 8 First groove end 9 Second groove end 10 workpieces 11 Workpiece longitudinal axis 12 Groove profile curve 13 Groove surface 14 Geometric Planes 15 First Laser Track 16 Second Laser Trail 17 Laser Beam 18 Beam axis 19 First intermediate profile curve 20 Intermediate groove 21 Groove surface of intermediate groove 22 Rotation Arrows 23 Laser beam deflection curve 24 Laser beam deflection curve 25 Geometric Planes 26 Laser Trail 27 Groove profile curve 28 groove surface 50 Laser processing equipment 51 Workpiece fixing device 53 Workpiece moving device 55 Device base 56 Laser 57 Laser beam deflector 58 Control Device

Claims

1. Using a laser processing device (50), 1. A method for laser-based machining of an elongated workpiece (10) having a shaft (2) extending in the direction of a workpiece longitudinal axis (11), comprising: By material removal using a laser beam (17), At least one groove (7) having a defined groove surface (13, 28) is created in the shaft (2), and the groove (7) extends at least along a portion of the outer surface of the shaft (2) between a first groove end (8) and a second groove end (9); the first groove end (8) is offset axially relative to the workpiece longitudinal axis (11) with respect to the second groove end (9); The laser processing equipment a workpiece clamping device (51) for receiving and clamping the workpiece (10); a workpiece moving device (53) for moving the workpiece fixing device (51) relative to the device base (55); a laser (56), A laser beam (17) of the laser is directed with a geometric beam axis (18) of the laser beam onto a workpiece (10) accommodated in a workpiece fixture (51), A laser processing device (50) The workpiece (10) is positioned in the workpiece fixture (51) and is configured to orient the workpiece (10) relative to the laser beam (17), and to move the laser beam (17) relative to the workpiece (10). The method comprising the following method steps: Arranging the workpiece (10) in the workpiece fixture (51) such that the first axial end (5) of the shaft (2) is accommodated in the workpiece fixture (51); Removal of material with a laser beam (17) from a second axial end (6) of the shaft (2) opposite the first axial end (5) in the direction towards the first axial end (5) or in the opposite direction; In that case, a groove (7) is formed between a first groove end (8) directed towards the first axial end (5) and a second groove end (9) directed towards the second axial end (6), a laser beam (17) is directed with its beam axis (18) onto the surface of the workpiece (10) and guided along a laser trajectory (15, 16, 26); the laser trajectories (15, 16, 26) extend exclusively parallel to the groove profile curves (12, 27), the groove profile curve (12, 27) corresponds to a set of intersection lines between the groove surface (13, 28) to be generated and the geometric plane (14, 25), the set of intersection lines forming an angle β with the workpiece longitudinal axis (11) such that 90° ≥ β ≥ the groove inclination angle; and The geometric planes (14, 25) together with the groove profile curves (12, 27) and the laser trajectories (15, 16, 26) moved in an axial direction relative to the workpiece longitudinal axis (11) during material removal between the first groove end (8) and the second groove end (9); the distance d between the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) is predetermined and remains constant throughout all material removal between the first groove end (8) and the second groove end (9); the distance d is predetermined so that the material of the workpiece (10) located on the side of the laser path (15, 16, 26) facing away from the groove profile curve (12, 27) in the geometrical plane (14, 25) is completely sublimated or vaporized during the guidance of the laser beam (17) along the laser path (15, 16, 26) depending on the power density of the laser beam (17), a laser beam (17) with a beam axis (18) of the laser beam, so that at the point of irradiation on the workpiece (10) this beam axis (18) forms an angle δ with the tangent of the groove surface to be produced, where 1°≦δ≦10°; guided along a laser trajectory (15, 16, 26), A method characterized by method steps.

2. The material is removed in multiple layers; a laser beam (17) is guided along a first laser trajectory (15) parallel to the groove profile curve (12, 27) during removal of the first layer extending from the first groove end (8) to the second groove end (9); the first laser trajectory has a first spacing d1 relative to the groove profile curve (12, 27) during the removal of the first layer; and a laser beam (17) is guided along a second laser trajectory (16) parallel to the groove profile curve (12, 27) during removal of the second layer extending from the first groove end (8) to the second groove end (9); the second laser trajectory has a second spacing d2 relative to the groove profile curve (12, 27) during the removal of the second layer, and The second distance d2 is smaller than the first distance d1.

2. The method of claim 1 .

3. until a groove surface (13, 28) is generated.

3. A method according to claim 2, characterized in that in further layers material is removed along further laser trajectories parallel to the groove profile curve (12, 27) at decreasing intervals relative to the groove profile curve (12, 27).

4. The material removal is performed by a pulsed laser beam (17).

4. The method according to claim 1, wherein the first and second electrodes are connected to a first electrode.

5. the laser pulse has a pulse duration of 10 ps or less; 5. The method of claim 4.

6. the laser beam (17) is guided multiple times along laser trajectories (15, 16, 26) parallel to the groove profile curve (12, 27); and the laser beam (17) is then moved along the laser trajectory (15, 16, 26) first in one direction and then in the opposite direction, 6. The method according to claim 1, wherein the first and second electrodes are connected to a first electrode.

7. After guiding the laser beam (17) along a laser trajectory (15, 16, 26) parallel to the groove profile curve (12, 27) from one end of the laser trajectory (15, 16) to the other end of the laser trajectory (15, 16), The workpiece (10) is moved in the direction of the workpiece longitudinal axis (11) with a workpiece moving device (53), and in so doing, the workpiece (10) is advanced relative to the laser beam (17); 7. The method according to claim 1, wherein the first and second electrodes are connected to a first electrode.

8. The workpiece (10) is rotated about the workpiece longitudinal axis (11) during laser processing by a workpiece moving device (53).

8. The method according to claim 1, wherein the first and second electrodes are connected to a first electrode.

9. The distance d between the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) is At the position of this laser beam on the workpiece surface, the diameter is equal to or greater than half the diameter of the laser beam (17); 9. The method according to any one of claims 1 to 8.

10. a second movement of the laser beam (17) superimposed on a first movement of the laser beam (17) along a laser trajectory (15, 16, 26) parallel to the groove profile curve (12, 27); and said second movement being generated using a laser beam deflection device (57); 10. The method according to any one of claims 1 to 9, characterized in that

11. the second movement is performed along a laser beam deflection curve (23, 24), the laser beam deflection curve having a diameter m; and the distance d between the groove profile curve (12, 27) and the laser trajectory (15, 16, 26) parallel to the groove profile curve (12, 27) is equal to or greater than half the diameter m of the laser beam deflection curve (23, 24) of this second movement; The method of claim 10, wherein:

12. 12. The laser processing apparatus according to claim 1, wherein a cutting tool is manufactured.

13. This is a laser processing device, a workpiece fixing device (51) for receiving and fixing the workpiece (10); a workpiece moving device (53) that moves the workpiece fixing device (51) relative to the device base part (55); a laser (56); A laser beam (17) of the laser is directed with a geometric beam axis (18) of the laser beam onto a workpiece (10) accommodated in a workpiece fixture (51), A laser processing device (50) To orient a workpiece (10) disposed within a workpiece fixture (51) relative to a laser beam (17), and to move the laser beam (17) relative to the workpiece (10); and A laser processing device configured to remove material from a workpiece (10) with a laser beam (17), The laser processing device (50) comprises a control device (58), which controls the laser processing device (50) according to any one of claims 1 to 12. A laser processing device characterized by:

14. 14. The laser processing apparatus according to claim 13, characterized in that it comprises a laser beam deflection device (57).

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