METHOD FOR LASER-BASED PROCESSING OF A WORKPIECE AND LASER PROCESSING APPARATUS FOR CARRYING OUT THE PROCESS - Patent application

Abstract

A method and an apparatus for laser-based processing of workpieces 4, 24, 54 are proposed, in which a given three-dimensional outer workpiece shape 21 with a workpiece contour 1 is generated in the workpiece 4, 24, 54 by material removal with the laser beam 2, 52 using a laser processing apparatus 50 comprising a workpiece fixture 51 for receiving and fixing the workpiece 4, 24, 54, a movement device 53 for moving the workpiece fixture relative to the apparatus base 55, and a laser 56 for generating a laser beam 2, 52 aligned along a beam axis 2a, 22a and having a laser deflection device 57 for purposefully deflecting the laser beam 2, 52, while simultaneously moving the workpiece 4, 24, 34, 54, guiding the laser beam 2, 22, 52 and feeding the workpiece 4, 24, 54 and / or the laser beam 2, 22, 52.

Description

[Technical field]

[0001] The present invention relates to a method for laser-based processing of a workpiece. [Background technology]

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

[0003] For the laser processing, the laser beam and the workpiece are aligned relative to one another in a defined manner and, if necessary, moved in order to selectively remove material in a given area of ​​the workpiece and to form a defined workpiece contour on the surface of this workpiece, which includes, for example, the creation of cutting edges or other edges on the workpiece.

[0004] The laser processing device is equipped with a laser, which generates a laser beam that extends along a beam axis, whereby the beam axis corresponds to a geometrical straight line. The laser has a laser head, which 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 predefined workpiece contour. The workpiece is arranged in an orientation and positioning device, which in the machine tool is also called a chuck device. The apparatus includes a machine base, a workpiece fixing device, and a moving device. The machine base is arranged in a fixed position. The machine base can be a part of a machine base of a laser processing apparatus. The workpiece fixture receives the workpiece 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 moving device serves for the movement of the workpiece fixture relative to the machine base, and since the laser head of the laser processing machine is usually arranged in a fixed position in relation to the machine base, the moving device accordingly also serves for the relative movement between the laser head on the one hand and the workpiece fixture on the other hand. Correspondingly, this causes the workpiece clamped in the workpiece clamping device to be moved relative to the laser beam generated by the laser head, so that, as long as the workpiece surface is not covered by the workpiece clamping device, the processing of the workpiece can be carried out on all surfaces of the workpiece thanks to the relative movement caused by the movement device. During machining, the workpiece is aligned with the surface of the workpiece at different angles to the laser beam. The laser head is equipped with a laser deflection device, which deflects the laser beam purposefully by means of optical components and thus guides it along the surface of the workpiece at high speed. The deflection device serves for an additional relative movement of the laser beam and the workpiece. The speed at which the laser deflection device moves the laser beam is typically greater than the speed at which the motion device moves the workpiece relative to the device base.

[0005] For machining a workpiece, the laser beam is usually directed with the beam axis of the laser beam towards the workpiece to be machined such that the beam axis is directed perpendicular to the surface of the workpiece. Subsequently, layers of material are removed from the surface of the workpiece until the workpiece has the desired workpiece shape. This type of method is only suitable for machining small areas of the workpiece because layer-by-layer material removal is very time consuming.

[0006] For machining a workpiece along its entire outer surface, in particular for generating an outer workpiece contour that extends around its circumference, this type of method with layer-by-layer material removal is unsuitable for time and cost reasons, as is the case, for example, when drills or reamers are to be produced from a cylindrical blank. Summary of the Invention [Problem to be solved by the invention]

[0007] The problem underlying the present invention is to provide a method and an apparatus for laser-based processing of a workpiece, By means of these methods and devices, workpieces can be produced with high precision from a blank, which have a predefined outer workpiece shape which extends all around at least in an axial portion, The workpiece then remains clamped in the workpiece clamping device throughout the entire processing and re-clamping of the workpiece is eliminated. [Means for solving the problem]

[0008] This problem is solved by a method having the features of claim 1 and by a laser processing device having the features of claim 17. An elongated workpiece to be processed extends along a geometrical workpiece longitudinal axis, in which a predefined three-dimensional outer workpiece shape with a workpiece contour is generated by material removal with the aid of a laser beam. The workpiece contour then corresponds to a set of intersections of the three-dimensional outer workpiece shape to be generated with a geometrical workpiece plane, through which the geometrical workpiece longitudinal axis extends, and extends between a first point A and a second point B, whereby points A and B are offset from one another at least in the axial direction. The method according to claim 1 comprises: The workpiece is placed in a workpiece fixture of the laser processing apparatus; and three movements superimposed on one another are carried out simultaneously, which movements induce targeted material removal in the workpiece; It is characterized by: The first movement is a workpiece rotation movement during which the workpiece fixture rotates the workpiece about a geometric workpiece longitudinal axis. The rotation is endless: the workpiece performs a continuous sequence of complete rotations, and since the workpiece is rotated about the geometrical workpiece longitudinal axis, the rotation takes place about a workpiece constraint rotation axis. The second movement is the purposeful guidance of the laser beam. The laser beam is moved by means of the laser deflection device along a pre-defined laser path, which corresponds to the workpiece contour of a pre-defined three-dimensional workpiece shape between point A and point B. During the guidance of the laser beam, the laser beam is either oriented perpendicular to the geometrical workpiece plane or forms an angle of up to 10° with the normal to the workpiece plane, which in that case is a straight line perpendicular to the workpiece plane. The laser beam is guided along the laser path between points A and B several times during the second movement. The third movement is a feed movement in which the workpiece fixture and / or the laser beam are fed forward until a surface of the workpiece positioned in the workpiece fixture comes into contact with the laser beam such that the laser beam is oriented tangentially to the workpiece surface or forms an angle of up to 10° with the tangent of the workpiece surface. The laser beam then removes material at the surface of the workpiece and generates a pre-given three-dimensional outer workpiece shape having the workpiece contour. In that case, the three movements are overlapped in time: the first movement, the second movement and the third movement are performed simultaneously and parallel to one another until the predefined workpiece shape is generated in the workpiece. Effect of the Invention

[0009] The workpiece is continuously rotated while material is removed from its outer surface with the laser beam so that material removal occurs around the entire outer periphery of the workpiece, similar to that of a lathe, and at least in an axial portion of the workpiece, which portion extends between both points A and B.

[0010] Material is then not removed in layers, but rather the entire area is removed along the perimeter of the workpiece. The first movement is a series of complete rotations of the workpiece about the geometric workpiece longitudinal axis. The second movement can be repeated as often as appropriate. For this purpose, the laser beam is moved back and forth several times along the laser path between the first point A and the second point B. The third movement serves for the contact of the rotated workpiece with the laser beam guided along the laser path outside the workpiece in a purposeful manner such that material is removed by said laser beam.

[0011] The workpiece contour of the workpiece is given in advance by the outer workpiece shape to be generated of the workpiece, which corresponds to a curved line that defines the workpiece with the outer workpiece shape to be generated from the periphery of the workpiece in the area to be machined in this way.

[0012] It is possible that a given three-dimensional outer workpiece shape has different cross-sections in both axial sections between points A and B. This induces that the workpiece contours between points A and B have different distances to the geometrical workpiece longitudinal axis.

[0013] Both points A and B are offset in the axial direction with respect to the geometrical workpiece longitudinal axis. It is possible that points A and B are additionally offset from one another in the radial direction.

[0014] During the second movement, the laser beam is oriented relative to the workpiece such that the beam axis of the laser beam is oriented perpendicular to a geometric workpiece plane in which the geometric workpiece longitudinal axis extends or forms an angle of at most 10° with the geometric workpiece plane.

[0015] The laser path corresponds to a set of intersection lines between a geometric workpiece plane and the three-dimensional outer workpiece shape to be generated, the set of intersection lines extending in the workpiece plane on either side of the geometric workpiece longitudinal axis. In a rotationally symmetric shape of the workpiece, the set of intersection lines is axially symmetric with respect to the geometric workpiece longitudinal axis. It is possible for the laser path to extend only on one side of the workpiece longitudinal axis or to extend on both sides of the workpiece longitudinal axis.

[0016] The first, second and third movements are coordinated with one another such that each appropriate outer workpiece shape of the workpiece can be generated, including rotationally symmetric workpiece shapes and non-rotationally symmetric workpiece shapes, such as outer workpiece shapes having flat surfaces.

[0017] With the method according to the invention, an outer workpiece shape can be generated which extends around the entire outer periphery of the workpiece and which has an axial extent relative to the workpiece longitudinal axis. The workpiece remains clamped within the workpiece fixture throughout the process. The process is fast and accurate.

[0018] An important advantage of the method according to the invention is that in the focused laser beam the focal point is always located at the position to be processed or in the close vicinity of this position during the laser processing, which allows optimal processing of the workpiece.

[0019] According to yet another advantageous embodiment of the invention, the laser beam is guided along the laser path from point A to point B and subsequently from point B to point A. This movement can be repeated as often as appropriate until a pre-given workpiece shape is generated in the workpiece.

[0020] According to yet another advantageous embodiment of the invention, the laser beam is moved from point A to point B along the laser path multiple times, with the movement of the active laser beam occurring exclusively in the direction from point A to point B or not in the opposite direction from point B to point A. In order to guide the laser beam back again to point A after reaching point B, the laser beam is switched off during the return guidance or, in the activated laser beam, this return guidance is performed along a curved line which deviates from the laser path AB given in advance by the workpiece contour to be generated of the workpiece, This curve then extends outside the workpiece to be processed in order to avoid undesired interactions between the laser beam and the workpiece.

[0021] According to yet another advantageous embodiment of the invention, the laser beam is moved during the second movement along the laser path essentially perpendicular to the beam axis from point A to point B. The movement direction of the laser beam during the second movement is accordingly essentially perpendicular to the beam axis of this laser beam.

[0022] According to yet another advantageous embodiment of the invention, the first point A and the second point B are axial limits of the three-dimensional outer workpiece shape to be generated relative to the workpiece longitudinal axis. The laser processing extends between the limits of point A and point B.

[0023] According to yet another advantageous embodiment of the invention, the laser beam additionally performs a fourth movement, in which the laser beam is moved around a center in an open or closed curve. In that case, this fourth movement is superimposed on the second movement, the center of which lies on the curve that is given in advance by the course of the workpiece contour to be generated, and the diameter of the laser beam can then be taken into account as an offset. The laser beam accordingly moves from the first point A to the second point B along the workpiece contour to be generated according to the second movement and is simultaneously guided along a small closed or open curve according to the fourth movement. The laser beam 2 is then not guided along a straight, curved or irregularly shaped line corresponding to the workpiece contour to be generated, but rather performs a loop-like movement with the fourth movement around the workpiece contour to be generated. This allows the area of ​​the workpiece from which material removal takes place during irradiation of the workpiece with the laser beam to be enlarged, the extent of the open or closed curve being small compared to the workpiece contour to be generated. A closed curve can be, for example, a circle, an ellipse, or the figure 8. An open curve is characterized by the fact that the start and end points of the curve are not coincident.

[0024] According to yet another advantageous embodiment of the present invention, The ratio between the diameter of the open or closed curve and the diameter of the laser beam (2, 52) when irradiating the workpiece (4, 24, 54) is between 1.2 and 150. This ensures that the extent of the open or closed curve is small compared to the workpiece contour to be generated, which in an advantageous manner has a diameter between 0.05 and 2.0 mm. The diameter of the laser beam when irradiating the workpiece is preferably between 0.008 and 0.03 mm, particularly preferably between 0.015 and 0.03 mm.

[0025] According to yet another advantageous embodiment of the invention, in said third movement, said workpiece clamping device is moved in a direction perpendicular to the geometrical workpiece longitudinal axis.

[0026] According to yet another advantageous embodiment of the invention, in the third movement, the workpiece clamping device is moved in a direction perpendicular to the beam axis of the laser beam.

[0027] According to yet another advantageous embodiment of the invention, in said third movement, said laser beam is moved in a direction towards a geometrical workpiece longitudinal axis.

[0028] According to yet another advantageous embodiment of the invention, the third movement comprises a linear movement in a radial direction with respect to the workpiece longitudinal axis.

[0029] According to yet another advantageous embodiment of the invention, the third movement comprises a linear movement in an axial direction relative to the workpiece longitudinal axis or parallel to this axial direction, it is possible that this third movement comprises a radial movement relative to the workpiece longitudinal axis and a superposition of an axial movement.

[0030] According to yet another advantageous embodiment of the invention, the laser beam is arranged with its beam axis: During removal of material at the surface of the workpiece, The workpiece is oriented parallel to the radial direction with respect to the geometric longitudinal axis. The feed movement of this third movement induces the focal point of the laser beam to be located on the surface of the workpiece, on the workpiece contour to be generated, or close to one of these points.

[0031] According to yet another advantageous embodiment of the invention, the laser beam is arranged with its beam axis: The workpiece is inclined in the axial direction by an angle α relative to a tangent to the surface of the workpiece shape to be generated, this angle α being between 1° and 10°. In that case, a tilt by an angle α to the tangent can be performed in each appropriate direction. The tangent to the surface defines, together with the beam axis, a plane. This plane can be, for example, perpendicular to the geometrical workpiece longitudinal axis or parallel to this geometrical workpiece longitudinal axis, and it is also possible for this plane to have any other suitable orientation relative to the geometrical workpiece longitudinal axis.

[0032] According to yet another advantageous embodiment of the invention, said third movement is controlled dependently on said second movement.

[0033] According to yet another advantageous embodiment of the invention, said third movement is controlled dependently on said first movement.

[0034] According to yet another advantageous embodiment of the invention, material removal is performed in the axial portion between points A and B along the entire circumference of the workpiece.

[0035] According to yet another advantageous embodiment, the workpiece rotation movement is performed at a constant speed during all the material removal, whereas alternatively the rotation speed can be varied depending on the second and third movements and / or depending on the outer workpiece shape to be generated.

[0036] According to a further advantageous embodiment of the invention, the workpiece arranged in the workpiece clamping device is rotated with a rotation speed of between 5 and 1,000 U / min, whereby this rotation speed can be kept constant throughout the entire processing or can be varied depending on the workpiece and / or depending on the workpiece shape to be produced. For rotationally symmetrical workpieces, a constant rotation speed between, for example, 50 and 300 U / min can be set, although this is not essential. In the case of a rotationally symmetric diameter of the workpiece, it is possible, for example, for the rotation speed to be lower at the start, as long as the laser beam has not yet touched the surface of the workpiece. As soon as the laser beam approaches the surface of the workpiece, the rotation speed can be increased. This has an effect on the amount of material removed from the surface of the workpiece, so that, despite the diameter of the workpiece changing due to material removal, the same amount of material can be achieved within a given time interval by, for example, changing and adapting the rotation speed.

[0037] According to yet another advantageous embodiment of the invention, during the second movement, which embodies the guidance of the laser beam, this laser beam moves with a speed between 0.05 m / s and 10 m / s.

[0038] According to yet another advantageous embodiment of the invention, the third movement, in which the workpiece clamping device and / or the laser beam are moved closer towards each other, is performed with a speed between 0.05 mm / s and 500 mm / s.

[0039] According to a further advantageous embodiment of the invention, the direction of rotation in which the workpiece clamping device rotates is changed during the laser processing of the workpiece.

[0040] A laser processing apparatus for carrying out the method according to the present invention comprises: This laser processing device, a workpiece fixing device for receiving and fixing a workpiece; a moving device that moves the workpiece fixing device relative to a device base portion; and a laser; The laser generates a laser beam directed along a beam axis, and the laser has a laser deflection device for deflecting the laser beam in a targeted manner. It is characterized by: In that case, a displacement device is formed for carrying out a workpiece rotational displacement of a workpiece arranged in the workpiece clamping device. This move is referred to as the first move. The laser deflection device is formed for guiding the laser beam and in so doing for moving the laser beam along a predetermined laser path, whereby the laser path extends from a first point A to a second point B and is predetermined by the course of the workpiece contour to be generated, this movement being referred to as the second movement. The moving device and / or the laser perform a feed movement such that the surface of the workpiece positioned in the workpiece fixture device comes into contact with the laser beam, whereupon the laser beam removes material from the surface of the workpiece and generates a predetermined outer contour of the workpiece. This feed movement is called the third movement. In this case, the laser processing apparatus is configured so that the first movement, the second movement, and the third movement are performed simultaneously and in coordination with one another.

[0041] According to yet another advantageous embodiment of the invention, the laser processing apparatus is equipped with a control device, which controls the first movement, the second movement and the third movement, thereby ensuring that the three movements are coordinated with each other. If the laser beam performs an additional fourth movement, the control device advantageously also controls this fourth movement.

[0042] Further advantages and advantageous embodiments of the invention can be seen from the following description, the drawings and the claims.

[0043] In the figure, an embodiment of the laser-based processing of a workpiece according to the invention is illustrated. [Brief description of the drawings]

[0044] [Figure 1] FIG. 1 is a diagram of a first example of laser-based processing of a workpiece. [Diagram 2] FIG. 2 is a view of the workpiece according to FIG. 1 at the start of processing. [Diagram 3] 2A-2D are views of the workpiece according to FIG. 1 at different points in the processing; [Figure 4] FIG. 4 shows a diagram of the alignment of the laser beam and the movement direction of the third movement during processing according to FIGS. 1 to 3 ; [Diagram 5] 4A-4C are diagrams of the selective deflection of the laser beam and the movement direction of the third movement during processing according to FIGS. 1 to 3; [Figure 6] 5 shows a diagram of the alignment of the laser beam and alternative movement directions of the third movement during processing according to FIG. 4; [Figure 7] 11 is a diagram of a second and fourth movement relative to the laser beam. [Figure 8] 11 is a diagram of a second and an optional fourth movement relative to the laser beam. [Figure 9a] FIG. 2 is a diagram of a workpiece in perspective at a relatively early stage of laser processing. [Figure 9b] FIG. 9b is a view of the workpiece in the state according to FIG. 9a in a front view. [Figure 10a] FIG. 2 is a diagram of a workpiece in perspective at the end of laser processing. [Figure 10b] FIG. 10b shows the workpiece in the state according to FIG. 10a in a front view. [Figure 11] 1A-1C are views of a workpiece in perspective and from a front view at different points in time during laser processing. [Figure 12] 1 is a diagram of a workpiece and a laser beam where the laser beam is positioned at different locations along the laser path. [Figure 13] FIG. 2 is a diagram of a second embodiment of laser-based processing of a workpiece. [Figure 13a] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13b] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13c] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13d] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13e] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13f] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13g] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13h] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13i] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13j] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13k] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13l] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13m] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 13n] 4A-4D are diagrams of a workpiece and laser beam according to a second embodiment at different points during laser processing. [Figure 14] FIG. 2 is a diagram of an embodiment of laser-based processing of a workpiece not in accordance with the present invention. [Figure 15] FIG. 15 is a view of the workpiece according to FIG. 14 before the start of laser processing. [Figure 16] FIG. 15 is a view of the workpiece according to FIG. 14 at the start of laser processing. [Figure 17] 15 is a view of the workpiece according to FIG. 14 during laser processing. [Figure 18] 15 is a view of the workpiece according to FIG. 14 after completion of the laser processing. [Figure 19] FIG. 2 is a perspective view of the laser processing device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0045] 1 to 12 a first method for laser-based processing of a workpiece 4 by means of a laser beam 2 is illustrated. The workpiece 4 is first of all present as a blank. This blank has the shape of a cylinder. The workpiece 4 is clamped in a workpiece fixture of the laser processing machine. A laser processing machine 50 is shown in Fig. 19, which comprises a workpiece fixture 51, a movement device 53 and a laser 56. The movement device 53 serves for the movement of the workpiece fixture 51 relative to the machine base 55. Rotation of the workpiece fixture 51 together with the workpiece 4 or 54 accommodated therein, around a geometric axis coinciding with the geometric workpiece longitudinal axis 5, is, for example, considered as part of this movement. The workpiece longitudinal axis 5 then runs through the workpiece 4. What is being dealt with here is therefore the constraint axis of rotation of the workpiece. In the case at issue here, the workpiece 4 has the shape of a cylinder prior to laser processing. This cylinder is rotationally symmetrical with respect to the geometrical workpiece longitudinal axis 5. In rotating about the workpiece longitudinal axis 5, the workpiece 4 performs a continuous sequence of complete rotations. This movement is referred to as the first movement. This movement is illustrated in Figures 2 to 6 by a circular arrow on the right side beside the workpiece 4.

[0046] By laser processing, an outer workpiece shape should be generated in the workpiece, which has a workpiece contour 1. In the embodiment according to Figures 1 to 12, the workpiece shape to be generated is rotationally symmetrical with respect to the geometrical workpiece longitudinal axis 5.

[0047] A laser beam 2 with a geometric beam axis 2a is generated by a laser 56 illustrated in Fig. 19 and is guided along the workpiece contour 1 using a laser deflection device illustrated in Fig. 19. This movement of the laser beam is called the second movement. A laser path 3 is predefined by the workpiece contour 1. This laser path extends from a first point A to a second point B. The offset between the workpiece contour 1 and the laser path 3 is based on the radius of the laser beam 2 in the geometrical workpiece plane 8, which is illustrated in Figures 9a, 9b, 10a and 10b. It is then taken into account that the laser beam 2 can remove material in the workpiece 4 not only at one point in the center of the laser beam, but also in a circular area.

[0048] The laser beam 2 is guided along the laser path between points A and B multiple times during the laser processing until so much material has been removed in the workpiece 4 with the laser beam 2 that a pre-given outer workpiece shape has been produced. In that case, the laser beam can be moved back and forth between points A and B, or it can be guided always in only one direction, from point A to point B or from point B to point A. The number of cycles the laser beam 2 needs to be guided along the laser path 3 depends on the type and amount of material to be removed and on the laser.

[0049] Advantageously, the laser is a pulsed laser, whereby a short laser pulse produces a high energy density at the surface of the workpiece, without undesired heat input into the workpiece, and the duration of the laser pulse is advantageously in the picosecond or femtosecond range.

[0050] By the feed movement in which the workpiece fixture and / or the laser beam 2 are advanced, the surface of the workpiece 4 positioned in the workpiece fixture comes into contact with the laser beam 2, whereby material on the surface of the workpiece 4 is removed by the laser beam 2 and the workpiece contour 1 is gradually generated. This feed movement is called the third movement. In FIGS. 1 to 6 , this feed movement is a linear movement of the workpiece 4 perpendicular to the geometrical workpiece longitudinal axis 5 with a movement direction 6 . 6, it is additionally shown that the laser path 3 is displaced in the direction of the geometrical workpiece longitudinal axis 5. What is being dealt with here is a translation of the laser path 3 in the direction marked by an arrow.

[0051] The first, second and third movements are carried out simultaneously, being superimposed on one another, whereby by means of the laser beam 2 material is removed at the surface of the workpiece 4, gradually generating a predefined workpiece shape of the workpiece 4. This is illustrated in FIG. In a first embodiment, the laser beam 2 illustrated in Figures 1, 4, 5 and 6 first contacts the workpiece 4 at a contact point 7 illustrated in Figure 2. This contact point 7 coincides with the first point A of the laser path 3.

[0052] It is possible that the laser beam 2 is oriented with its beam axis 2a perpendicular to the workpiece plane 8. The workpiece plane 8 is a geometrical plane that extends through the workpiece. The geometrical workpiece longitudinal axis 5 extends in this workpiece plane. Workpiece planes 8 are illustrated in Figures 9a, 9b, 10a and 10b. Basically, there are four possible workpiece planes that extend through the workpiece 4 and in which the workpiece longitudinal axis 5 extends. All planes that satisfy these conditions intersect at the workpiece longitudinal axis 5. The workpiece plane 8 illustrated in Figures 9a, 9b, 10a, and 10b is characterized by the laser beam 2 being perpendicular to the workpiece plane 8. Perpendicular orientation of the laser beam 2 is illustrated in Figures 4, 6, 9a, 9b, 10a, and 10b. When the laser beam 2 is perpendicular to the workpiece plane 8, the laser beam 2 extends tangentially to the surface of the workpiece 4 during material removal. Alternatively to this, it is possible for the laser beam 2 to be tilted by an angle α in comparison with this perpendicular orientation. The straight line perpendicular to the workpiece plane 8 is also called the normal line. The beam axis 2a of the laser beam 2 extends perpendicular to the workpiece plane 8 or makes an angle of up to 10° with the normal to this workpiece plane 8. The laser beam 2 and the workpiece 4 are brought into contact with each other such that the laser beam 2 is directed tangentially to the rotating workpiece surface or makes an angle of up to 10° with the tangent to the workpiece surface. This is illustrated in FIG. This illustration shows that the beam axis 2a of the laser beam 2 can be oriented in different directions relative to the tangent of the workpiece surface at the point to be machined. The laser focus 9 is advantageously located at or near the surface of the workpiece 4. 5 shows, by way of example, four different directions in which the laser beam 2 can be tilted with its beam axis. At angles α1 and α2, the beam axis of the laser beam 2 and the tangent of the point to be machined on the surface of the workpiece 4 extend in one plane, which is parallel to the workpiece longitudinal axis 5. At angles α3 and α4, the beam axis of the laser beam 2 and the tangent of the point to be machined on the surface of the workpiece 4 extend in one plane, which is perpendicular to the workpiece longitudinal axis 5. The inclination of the laser beam by the angle α can, however, also be performed at any different angle. The angles α, α1, α2, α3, α4 between the beam axis of the laser beam 2 and the tangent of the workpiece shape to be generated of the workpiece have values ​​between 1° and 10°.

[0053] 7 and 8 an additional displacement of the laser beam 2 is illustrated, which displacement is referred to as the fourth displacement. The laser beam 2 is additionally displaced along a circular closed curve 10 or an irregularly shaped curve 11 in the guidance of this laser beam 2 along the laser path 3.

[0054] 9a, 9b, 10a, 10b, 11 and 12, the workpiece 4 and the laser beam 2 are shown in different views and at different times during the laser processing. The illustrations show that the focal point 9 of the laser beam 2 is located very close to the surface of the workpiece 4. Figure 11 further shows the view of the workpiece 4 at different sections of the laser processing, while Figure 12 shows how the laser beam 2 is guided during the second movement relative to the workpiece 4 and how it is then moved along a pre-given laser path 3. The first illustration in Fig. 12 shows the laser beam 2 at a first point A. The last illustration in Fig. 12 shows the laser beam 2 at a second point B. In this last illustration in Fig. 12, the laser processing has been completed. The workpiece now has a three-dimensional outer workpiece shape to be generated. The outer workpiece shape to be generated is further shown in Fig. 10a and in the penultimate view of Fig. 11. The predefined outer workpiece shape has different cross sections in different axial sections, whereby the predefined outer workpiece shape is generally rotationally symmetrical. The remaining illustrations in FIG. 12 show the laser beam 2 at positions on the laser path 3 between points A and B.

[0055] In Figures 9a and 10a, the laser path 3 is illustrated as a collection of intersection lines between the geometric workpiece plane 8 and the outer workpiece shape to be generated.

[0056] In Figures 13 and 13a to 13n a second embodiment of the laser processing is shown, which differs from the first embodiment of Figures 1 to 12 in that a workpiece 24 has an outer workpiece shape 21 to be generated, which has flat surfaces. The workpiece 24 has, after completion of the laser machining, hexagonal cross sections of different sizes in the machined parts. The workpiece shape to be produced is therefore not rotationally symmetric. This outer workpiece shape is A first movement, i.e. a rotation of the workpiece 24 about the geometric workpiece longitudinal axis 25; by superposition with a second movement corresponding to the guidance of the laser beam along a predetermined laser path between both points A and B according to the outer workpiece shape 21 to be generated, and By a third movement in the form of a feed movement in the direction 26 is generated. In that case, the laser beam 22 is oriented with its beam axis 22a perpendicular to a workpiece plane 28, in which the geometrical workpiece longitudinal axis 25 extends. This workpiece plane 28 is illustrated in FIG. 13b. Both points A and B, which are the limits of the workpiece contour in the axial direction, are offset in the axial direction with respect to the geometrical workpiece longitudinal axis 25. Both points A and B are furthermore offset in the radial direction.

[0057] 13a to 13n show different stages of material removal and the associated orientation of the laser beam 22 relative to the workpiece 24 in axial cross-section according to FIG. The arrows 26 in Figures 13c, 13e, 13g, 13i, 13k and 13m show how the feed movement, referred to as the third movement, is coordinated with the rotational movement, referred to as the first movement, of the workpiece 24 about its geometric workpiece longitudinal axis 25 and with the position of the laser beam 22 along the laser path between points A and B in order to generate a pre-given angular cross-section that is assigned to the associated axial section. The workpiece shape 21 can then be generated in a cylindrical workpiece, as is illustrated in Figure 1. Figures 13b, 13d, 13f, 13h, 13j, 13l, and 13n show that the orientation of the laser beam 22, relative to the workpiece plane 28, does not change during laser processing.

[0058] In Figures 14 to 18, a non-inventive embodiment of the laser processing is shown, which differs from the first embodiment according to Figures 1 to 12 in that the laser beam 32 is oriented with its beam axis radially relative to the geometrical workpiece longitudinal axis 35 of the workpiece 34 during material removal. The laser beam 32 is guided along a laser path 33, which is predetermined by the workpiece contour 31 to be generated of the workpiece 34. A feed movement according to the third movement is performed in the direction 36. 15 shows the workpiece 34 and laser beam 32 before the start of laser processing. The workpiece has the shape of a cylinder at this stage. In Fig. 16 the laser processing begins. By means of the feed movement of the third movement the workpiece 34 is moved towards the laser beam 32 so that the focal point 39 is located in the area of ​​the workpiece contour 31 to be generated. By means of the arrow 40 the rotation of the workpiece 34 about the workpiece longitudinal axis 35 according to the first movement is illustrated. Fig. 17 shows the workpiece 34 after already a part of the material on the outside has been removed. Fig. 18 shows the finished workpiece at the end of the laser processing.

[0059] In Fig. 19, a laser processing apparatus 50 for carrying out this method is illustrated. The laser processing apparatus 50 includes: A workpiece fixing device 51 for receiving and fixing a workpiece 54; A moving device 53 that moves a workpiece 54 placed in the fixing device relative to a device base portion 55; A laser 56 generating a laser beam 52; and A laser deflection device 57 for guiding the laser beam 52; It is equipped with: The displacement device 53 has three linear axes X, Y, Z in the case under consideration here, and two rotation axes B and C. The rotation axis C serves in this case for the rotation of a workpiece 54 arranged in the workpiece clamping device 51 about a geometrical workpiece longitudinal axis extending through the workpiece. The laser deflection device 57 moves and guides the laser beam 52 in three different directions in space, where the laser beam 52 is moved relative to the workpiece 54 along a laser path that is not shown in FIG. For this purpose, the laser deflection device 57 comprises a number of mirrors, which can deflect the laser beam in a targeted manner, and is further equipped with at least one lens, which focuses the laser beam 52 onto the surface of the workpiece 54. These mirrors and lenses are not shown in the figures.

[0060] All features may be essential to the invention both individually as well as in any suitable combination with one another. In addition, the present application relates to the invention described in the claims, but may also include the following as other aspects. 1. A method for laser-based machining of an elongated workpiece (4, 24, 54) extending along a geometric workpiece longitudinal axis (5, 25), comprising: a workpiece fixing device (51) for receiving and fixing the workpiece (4, 24, 54); A moving device (53) for moving the workpiece fixing device relative to a device base portion (55); and a laser (56) generating a laser beam (2, 52) directed along a beam axis (2a, 22a) and having a laser deflection device (57) for deflecting said laser beam (2, 52) in a targeted manner; Using a laser processing device (50) comprising: a predetermined three-dimensional outer workpiece shape (21) having a workpiece contour (1) is generated in the workpiece (4, 24, 54) by material removal using the laser beam (2, 52); the workpiece contour (1) corresponds to a set of intersections of the three-dimensional outer workpiece shape (21) to be generated with a geometrical workpiece plane (8, 28) through which the geometrical workpiece longitudinal axis (5, 25) extends, the workpiece contour (1) extends between a first point A and a second point B, and the points A and B are offset from one another at least in the axial direction; In the method, The method comprises the following method steps: - positioning the workpiece (4, 24, 54) in the workpiece clamping device (51); -Perform the following three movements: a first movement which is a workpiece rotation movement; During the rotational movement of the workpiece, the workpiece fixing device (51) is driven to rotate by the moving device (53), and In that case, the workpiece (4, 24, 54) arranged in the workpiece fixture (51) is rotated endlessly about the geometrical workpiece longitudinal axis (5, 25) and performs a continuous sequence of complete rotations, a second movement, which is the guidance of the laser beam (2, 52); the laser beam (2, 52) is moved along a predefined laser path (3) by means of the laser deflection device (57), This laser path corresponds to the workpiece contour (1) between point A and point B, the laser beam (2, 22) is oriented perpendicular to the geometric workpiece plane (8, 28) or forms an angle of up to 10° with the normal to the workpiece plane (8, 28); the laser beam (2, 25) is guided along the laser path (3) between points A and B multiple times during the second movement, A third movement, which is a feed movement; In this feed movement, the workpiece clamping device (51) and / or the laser beam (2, 25) are fed forward, The surface of the workpiece (4, 24, 54) placed in the workpiece fixture (51) is exposed to the laser beam (2, 25) and such that the laser beam is oriented tangentially to the surface of the workpiece (4, 24, 54) or forms an angle of up to 10° with the tangent of the surface of the workpiece (4, 24, 54), Contact said laser beam (2, 25) removes material at said surface of said workpiece (4, 24, 54) and generates a pre-given three-dimensional outer workpiece shape (21) having said workpiece contour (1, 21); the first movement, the second movement and the third movement are performed simultaneously and parallel to one another until the pre-given workpiece shape (21) having the workpiece contour (1) is generated in the workpiece (4, 24, 54). A method comprising the steps of: 2. The method according to claim 1, characterized in that the laser beam (2, 52) is guided along the laser path (3) from point A to point B and subsequently from point B to point A. 3. A method as described in claim 1 or 2, characterized in that during the second movement, the laser beam (2, 52) is moved perpendicular to the beam axis along the laser path (3) from point A to point B. 4. The first point A and the second point B are: the limit of the outer workpiece shape (21, 31) to be produced by the method in an axial direction relative to the geometric workpiece longitudinal axis (5, 25), 4. The method according to any one of claims 1 to 3, characterized in that 5. The laser beam (2, 52) performs an additional fourth movement, in which the laser beam (2, 52) is moved around a center in an open or closed curve; and the fourth movement being superimposed on the second movement; 5. The method according to any one of claims 1 to 4, characterized in that 6. The ratio between the diameter of the open or closed curve and the diameter of the laser beam (2, 52) when irradiating the workpiece (4, 24, 54) is between 1.2 and 150; 6. The method according to claim 5, characterized in that 7. A method according to any one of claims 1 to 6, characterized in that in the third movement, the workpiece fixing device (51) is moved in a direction perpendicular to the beam axis of the laser beam (2, 52). 8. A method according to any one of claims 1 to 7, characterized in that in the third movement, the laser beam (2, 52) is moved in a direction towards the workpiece (4, 24, 54). 9. A method according to any one of claims 1 to 8, characterized in that the third movement comprises a linear movement in a radial direction with respect to the geometric workpiece longitudinal axis (5, 25). 10. A method according to any one of claims 1 to 9, characterized in that the third movement comprises a linear movement in an axial direction relative to the geometric workpiece longitudinal axis (5, 25) or parallel to this axial direction. 11. The laser beam (2, 22) is aligned with the beam axis of the laser beam. During removal of material at the surface of the workpiece (4, 24), 11. The method according to any one of claims 1 to 10, characterized in that the workpiece is aligned parallel to the radial direction with respect to the geometrical workpiece longitudinal axis (5, 25). 12. The laser beam (2, 52) is aligned with the beam axis of the laser beam. 12. The method according to any one of claims 1 to 11, characterized in that the workpiece (4, 24, 54) is inclined in the axial direction by an angle α relative to a tangent to the surface, the angle α being between 1° and 10°. 13. A method according to any one of claims 1 to 12, characterized in that the third movement is controlled in dependence on the second movement. 14. A method according to any one of claims 1 to 13, characterized in that the third movement is controlled in dependence on the first movement. 15. A method according to any one of claims 1 to 14, characterized in that material removal is carried out along the entire circumference of the workpiece (4, 24, 54) within the axial portion between points A and B. 16. A method according to any one of claims 1 to 15, characterized in that the workpiece rotational movement is performed at a constant speed during all of the material removal. 17. A laser processing apparatus for carrying out the method according to any one of 1 to 16 above, This laser processing device, The apparatus includes a workpiece fixing device (51) for receiving and fixing a workpiece (4, 24, 54), a moving device (53) for moving the workpiece fixing device (51) relative to an apparatus base part (55), and a laser (56), said laser generating a laser beam (2, 22, 52) directed along a beam axis (2a, 22a) and said laser having a laser deflection device (57) for purposefully deflecting said laser beam (2, 22, 52), A moving device (53) is provided for carrying out a first movement, which is a workpiece rotation movement, during which the workpiece clamping device (51) rotates and in which the elongated workpiece (4, 24, 54) arranged in the workpiece clamping device (51) is rotated endlessly about its geometrical workpiece longitudinal axis (5, 25) and performs a continuous sequence of complete rotations, the laser deflection device (57) is arranged for guiding the laser beam (2, 52) in a second movement and for moving the laser beam (2, 52) along a predefined laser path (3) in that case, said laser path (3) extends from a first point A to a second point B and said laser path (3) is predetermined by the course of said workpiece contour (1) of the three-dimensional outer workpiece shape to be generated, the moving device (53) and / or the laser (56) are configured to perform a feed movement as a third movement such that the surface of the workpiece (4, 24, 54) arranged in the workpiece clamping device (51) is brought into contact with the laser beam (2, 22, 25), said laser beam (2, 22, 25) removes material at said surface of said workpiece (4, 24, 54) and generates a predetermined outer workpiece shape (21) having said workpiece contour (1); the first movement, the second movement, and the third movement are performed simultaneously; A laser processing device characterized by: 18. The laser processing apparatus described in claim 17, characterized in that the laser processing apparatus (50) is equipped with a control device, and this control device controls the first movement, the second movement, and the third movement. [Explanation of symbols]

[0061] 1. The workpiece contour to be generated 2 Laser beam 2a Beam axis 3 Laser Path 4 Workpiece 5 Workpiece Longitudinal Axis 6 Direction of workpiece movement during the third movement 7 Point of contact between the laser beam and the workpiece at the start of laser processing 8 Workpiece Plane 9 Laser Focus 10. The closed curve of the laser beam movement according to the fourth movement 11 Open curve of laser beam movement according to the fourth movement 21 Workpiece shape to be generated 22 Laser Beam 22a Beam axis 24 Workpieces 25 Workpiece Longitudinal Axis 26 Direction of Feed Movement 28 Geometric workpiece planes 31 workpiece contour to be generated 32 Laser Beam 33 Laser Path 34 Workpiece 35 Workpiece Longitudinal Axis 36 Direction of Feed Movement 39 Laser Beam Focus 40 Rotation following the first movement 40 50 Laser processing equipment 51 Workpiece Fixing Device 52 Laser Beam 53 Workpiece moving device 54 Workpiece 55 Device base 56 Laser 57 Laser Deflection Device

Claims

1. A method for laser-based processing of an elongated workpiece (4, 24, 54) extending along a geometric workpiece longitudinal axis (5, 25), comprising: a workpiece fixing device (51) for receiving and fixing the workpiece (4, 24, 54); A moving device (53) for moving the workpiece fixing device relative to a device base part (55); and a laser (56) generating a laser beam (2, 52) aligned along a beam axis (2a, 22a) and having a laser deflection device (57) for deflecting said laser beam (2, 52) in a targeted manner; Using a laser processing device (50) comprising: a predetermined three-dimensional outer workpiece shape (21) having a workpiece contour (1) is generated in said workpiece (4, 24, 54) by material removal using said laser beam (2, 52); the workpiece contour (1) corresponds to a set of intersections of the three-dimensional outer workpiece shape (21) to be generated with a geometrical workpiece plane (8, 28) through which the geometrical workpiece longitudinal axis (5, 25) extends, the workpiece contour (1) extends between a first point A and a second point B, and the points A and B are offset from one another at least in the axial direction; In the method, The method comprises the following method steps: - positioning of said workpiece (4, 24, 54) in said workpiece fixture device (51); - carrying out the following three movements: a first movement which is a workpiece rotation movement; During this workpiece rotational movement, the workpiece fixing device (51) is driven to rotate by the moving device (53), and In that case, the workpiece (4, 24, 54) arranged in the workpiece fixture (51) is rotated endlessly about the geometrical workpiece longitudinal axis (5, 25) and performs a continuous sequence of complete rotations, a second movement, which is the guidance of the laser beam (2, 52); said laser beam (2, 52) is moved along a pre-given laser path (3) by means of said laser deflection device (57), This laser path corresponds to the workpiece contour (1) between point A and point B, the laser beam (2, 22) is oriented perpendicular to the geometric workpiece plane (8, 28) or forms an angle of up to 10° with the normal to the workpiece plane (8, 28); the laser beam (2, 25) is guided along the laser path (3) between points A and B a number of times during the second movement, a third movement which is a feed movement; In this feed movement, the workpiece clamping device (51) and / or the laser beam (2, 25) are fed forward, The surface of the workpiece (4, 24, 54) placed in the workpiece fixing device (51) is exposed to the laser beam (2, 25) and such that the laser beam is oriented tangentially to the surface of the workpiece (4, 24, 54) or forms an angle of up to 10° with the tangent of the surface of the workpiece (4, 24, 54), Contact said laser beam (2, 25) removes material at said surface of said workpiece (4, 24, 54) and generates a pre-given three-dimensional outer workpiece shape (21) having said workpiece contour (1, 21); the first movement, the second movement and the third movement are performed simultaneously and parallel to one another until the pre-given workpiece shape (21) having the workpiece contour (1) is generated in the workpiece (4, 24, 54). A method comprising the steps of:

2. 2. The method according to claim 1, characterized in that the laser beam (2, 52) is guided along the laser path (3) from point A to point B and subsequently from point B to point A.

3. 3. The method according to claim 1 or 2, characterized in that the laser beam (2, 52) is moved perpendicular to the beam axis along the laser path (3) from point A to point B during the second movement.

4. The first point A and the second point B are the limit of the outer workpiece shape (21, 31) to be generated by the method in an axial direction relative to the geometric workpiece longitudinal axis (5, 25), 4. The method according to claim 1, wherein the first and second electrodes are arranged in a first direction.

5. the laser beam (2, 52) performs an additional fourth movement, in which the laser beam (2, 52) is moved around a center in an open or closed curve; and the fourth movement being superimposed on the second movement; 5. The method according to claim 1, further comprising:

6. the ratio between the diameter of the open or closed curve and the diameter of the laser beam (2, 52) when irradiating the workpiece (4, 24, 54) is between 1.2 and 150; 6. The method of claim 5 .

7. 7. The method according to claim 1, wherein in the third movement, the workpiece fixing device (51) is moved in a direction perpendicular to the beam axis of the laser beam (2, 52).

8. 8. The method according to claim 1, wherein in the third movement, the laser beam (2, 52) is moved in a direction towards the workpiece (4, 24, 54).

9. 9. The method according to any one of claims 1 to 8, characterized in that the third movement comprises a linear movement in a radial direction with respect to the geometrical workpiece longitudinal axis (5, 25).

10. 10. The method according to claim 1, wherein the third movement comprises a linear movement in an axial direction relative to the geometrical workpiece longitudinal axis (5, 25) or parallel to this axial direction.

11. The laser beam (2, 22) is aligned with the beam axis of the laser beam, During removal of material at the surface of the workpiece (4, 24), 11. The method according to claim 1, wherein the workpiece is aligned parallel to a radial direction with respect to the geometrical workpiece longitudinal axis (5, 25).

12. The laser beam (2, 52) is aligned with the beam axis of the laser beam, 12. The method according to claim 1, wherein the workpiece (4, 24, 54) is inclined in the axial direction by an angle α relative to a tangent to the surface of the workpiece (4, 24, 54), the angle α being between 1° and 10°.

13. 13. The method according to any one of claims 1 to 12, wherein the third movement is controlled in dependence on the second movement.

14. 14. The method according to any one of claims 1 to 13, wherein the third movement is controlled in dependence on the first movement.

15. 15. A method according to any one of the preceding claims, characterized in that material removal is performed along the entire circumference of the workpiece (4, 24, 54) in the axial section between points A and B.

16. 16. A method according to any one of claims 1 to 15, wherein the workpiece rotational movement is performed at a constant speed during all of the material removal.

17. A laser processing apparatus for carrying out the method according to any one of claims 1 to 16, This laser processing device, The present invention comprises a workpiece fixing device (51) for receiving and fixing a workpiece (4, 24, 54), a moving device (53) for moving the workpiece fixing device (51) relative to an apparatus base part (55), and a laser (56), said laser generating a laser beam (2, 22, 52) aligned along a beam axis (2a, 22a) and said laser having a laser deflection device (57) for purposefully deflecting said laser beam (2, 22, 52), A moving device (53) is provided for carrying out a first movement, which is a workpiece rotation movement, during which the workpiece clamping device (51) rotates and in which the elongated workpiece (4, 24, 54) arranged in the workpiece clamping device (51) is rotated endlessly about its geometrical workpiece longitudinal axis (5, 25) and performs a continuous sequence of complete rotations, the laser deflection device (57) is formed for guiding the laser beam (2, 52) in a second movement and for moving the laser beam (2, 52) along a predefined laser path (3) in that case, said laser path (3) extends from a first point A to a second point B and said laser path (3) is predetermined by the course of said workpiece contour (1) of the three-dimensional outer workpiece shape to be generated, the moving device (53) and / or the laser (56) are configured to perform a feed movement as a third movement such that the surface of the workpiece (4, 24, 54) arranged in the workpiece clamping device (51) is brought into contact with the laser beam (2, 22, 25), said laser beam (2, 22, 25) removes material at said surface of said workpiece (4, 24, 54) and generates a pre-given outer workpiece shape (21) having said workpiece contour (1); the first movement, the second movement, and the third movement are performed simultaneously; A laser processing device characterized by:

18. The laser processing apparatus (50) according to claim 17, characterized in that the laser processing apparatus (50) is equipped with a control device, and the control device controls the first movement, the second movement, and the third movement.

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