Laser-based workpiece machining method and laser machining device for carrying out such method

Abstract

A method and device for laser-based machining of a workpiece (4, 24, 54), in which a predetermined workpiece shape (21) having a contour (1) is generated at the workpiece (4, 24, 54) by material removal by means of a laser beam (2, 22, 52) using a laser machining device (50), the device comprising a housing and fixing the workpiece (4, 24, 54), the invention relates to a device (1) for fixing a workpiece (2, 22, 52), comprising a device base (55), a workpiece fixing device (51) comprising a plurality of workpiece fixing devices (51, 54), a moving device (53) for moving the workpiece fixing device relative to the device base (55), and a laser (56) which generates a laser beam (2, 22, 52) which is guided along a beam axis (2a, 22a) and which has a laser deflection device (57) which exclusively deflects the laser beam (2, 22, 52). The guiding of the laser beam (2, 22, 52) and the feed movement of the workpiece (4, 24, 54) and / or the laser beam (2, 22, 52) are carried out while the workpiece (4, 24, 34, 54) is moved.

Description

[0001] The invention relates to a workpiece processing method based on laser.

[0002] It is known to use short, intense laser pulses to process workpieces. Laser radiation with a high power density causes the material on the workpiece surface to heat up. The surface of the workpiece locally reaches such a high temperature that the material of the workpiece evaporates or sublimates. When the laser power density is high, the electrons and ions of the removed material generate a plasma. Material removal is also called laser ablation or laser evaporation. For example, material can be removed in layers and evenly. Workpieces can also be cut using continuous or pulsed laser radiation. This is called laser cutting or laser beam cutting. The parameters of the laser radiation must be adapted to the material to be processed and the desired processing. The parameters of the laser radiation include the wavelength and the average power. If the laser radiation is pulsed, the parameters also include the pulse energy and the pulse duration.

[0003] For laser machining, the laser beam and the workpiece are aligned relative to each other in a defined manner and, if necessary, moved relative to each other in order to specifically remove material from a predetermined area of ​​the workpiece and to form a specific workpiece contour on the workpiece surface. This includes creating a cutting edge or other edge on the workpiece.

[0004] The laser processing device is equipped with a laser that generates a laser beam. The laser beam extends along a beam axis. The beam axis corresponds to a geometrical straight line. The laser comprises a laser head, which can irradiate the laser beam with its beam axis on the workpiece in a targeted manner and, if necessary, move the laser beam to the surface of the workpiece within a predetermined workpiece contour. The workpiece is placed in a device for alignment and positioning, which is also called a clamping device in a machine tool. The device is provided with a device base, a workpiece fixture and a moving device. The device base is arranged in a fixed manner. It can be part of the machine base of the laser processing device. The workpiece fixture accommodates the workpiece and clamps it firmly so that the position of the workpiece relative to the workpiece fixture does not change during the workpiece processing. The moving device moves the workpiece fixture relative to the device base. Since the laser head of the laser processing device is usually arranged in a fixed manner relative to the device base, the moving device also causes a relative movement between the laser head on the one hand and the workpiece fixture on the other hand. Correspondingly, the workpiece clamped to the workpiece fixture thereby moves relative to the laser beam generated by the laser head. Since the moving device triggers the relative movement, the entire surface of the workpiece can be processed as long as the workpiece surface is not covered by the workpiece fixture. During machining, the workpiece surface is aligned with the laser beam at different angles. The laser head can be equipped with a laser deflection device, which uses optical elements to deflect the laser beam in a targeted manner and thus guide it over the surface of the workpiece at high speed. The deflection device causes an additional relative movement of the laser beam and the workpiece. The speed at which the laser deflection device moves the laser beam is usually greater than the speed at which the translation device moves the workpiece relative to the device base.

[0005] To machine a workpiece, the laser beam is usually aligned with its beam axis towards the workpiece to be machined, so that the beam axis is aligned perpendicular to the surface of the workpiece. Material is then removed layer by layer from the workpiece surface until the workpiece has the desired shape. This method is only suitable for machining small areas of the workpiece, since the layer-by-layer removal of material is very time-consuming. For machining the workpiece along the entire side surface of the workpiece, in particular for producing workpiece outer contours extending on the circumference, this method of layer-by-layer material removal is not suitable for time and cost reasons. This applies, for example, if a drill or reamer is produced from a cylindrical blank.

[0006] The object of the present invention is to provide a method and a device for laser-based processing of workpieces, by means of which a workpiece having a predetermined outer workpiece shape can be processed from a blank with increased precision, the predetermined outer workpiece shape extending at least in an axial section over the entire circumference, wherein the workpiece remains clamped in a workpiece fixture during the entire processing process without the need for re-clamping the workpiece.

[0007] This object is achieved by a method having the features of claim 1 and a laser processing device having the features of claim 17. The elongated workpiece to be processed extends along a geometric longitudinal axis of the workpiece. By removing material using a laser beam, a predetermined three-dimensional outer workpiece shape with a workpiece contour is generated on the workpiece. The workpiece contour corresponds to the intersection of the three-dimensional outer workpiece shape to be processed and a geometric workpiece plane in which the geometric workpiece longitudinal axis extends. The workpiece contour extends between a first point A and a second point B, wherein points A and B are offset from each other at least in the axial direction. The method according to claim 1 is characterized in that the workpiece is arranged in a workpiece fixture of the laser processing device and three superimposed movements are simultaneously performed, which result in targeted removal of material from the workpiece:

[0008] The first movement is a workpiece rotation movement, in which the workpiece fixture rotates the workpiece around the geometric workpiece longitudinal axis. This rotation is endless. The workpiece performs a continuous complete rotation cycle. Due to the rotation of the workpiece around the geometric longitudinal axis, a rotation around the rotation axis connected to the workpiece is achieved.

[0009] The second movement is the targeted guidance of the laser beam. The laser beam is moved along a predetermined laser path by means of a laser deflection device. This laser path corresponds to the workpiece contour of the predetermined three-dimensional workpiece shape between points A and B. When the laser beam is guided, it is aligned perpendicularly to the geometric workpiece plane or forms an angle of up to 10° with the normal to the workpiece plane. The normal is a straight line perpendicular to the workpiece plane. During the second movement, the laser beam is moved several times along the laser path between A and B.

[0010] The third movement is a feed movement, in which the workpiece fixture and / or the laser beam are fed in such a way that the surface of the workpiece arranged in the workpiece fixture contacts the laser beam so that the laser beam is tangentially aligned with the workpiece surface or forms an angle of up to 10° with the tangent of the workpiece surface. The laser beam removes material from the workpiece surface and processes a predetermined three-dimensional outer workpiece shape according to the workpiece contour.

[0011] The three movements are superimposed in time. The first movement, the second movement and the third movement are performed simultaneously and parallel to each other until a predetermined workpiece contour is formed on the workpiece.

[0012] Since the workpiece is continuously rotated while material is removed from the exterior of the workpiece by the laser beam, material removal occurs in a lathe-like manner over the entire outer circumference of the workpiece, at least over the axial portion of the workpiece extending between points A and B.

[0013] The material is not removed in layers, but rather in entire areas over the circumference of the workpiece. The first movement is a series of complete rotations of the workpiece about the geometric longitudinal axis of the workpiece. The second movement can be repeated as desired. To this end, the laser beam moves back and forth several times along the laser path between the first point A and the second point B. The third movement ensures that the rotating workpiece and the laser beam guided along the laser path come into contact in such a way that the laser beam removes material exclusively from the outside of the workpiece.

[0014] The workpiece contour of the workpiece is predetermined by the respective workpiece shape of the workpiece to be machined. It corresponds to the curve which distinguishes the workpiece having the workpiece shape to be machined from its surroundings in the machining area to be machined in the method of use.

[0015] The predetermined three-dimensional outer workpiece shape may have different cross sections in an axial section between two points A and B. This means that the workpiece contour between point A and point B has different distances from the geometric workpiece longitudinal axis.

[0016] The two points A and B are offset in the axial direction relative to the longitudinal axis of the geometric workpiece. They can also be offset from each other in the radial direction.

[0017] During the second movement, the laser beam is aligned with the workpiece such that its beam axis is aligned perpendicularly to a geometrical workpiece plane in which the geometrical workpiece longitudinal axis extends or forms an angle of at most 10° with the geometrical workpiece plane.

[0018] The laser path corresponds to the intersection between the geometric workpiece plane and the three-dimensional outer workpiece shape to be machined. The intersection extends in the workpiece plane on both sides of the geometric workpiece longitudinal axis. For workpieces with a rotationally symmetrical shape, the intersection is axisymmetric with respect to the geometric longitudinal axis of the workpiece. The laser path can extend only on one side of the workpiece longitudinal axis or on both sides of the workpiece longitudinal axis.

[0019] The first, second and third movements are coordinated with each other so that any external shape of the workpiece can be machined. These include rotationally symmetrical workpiece shapes and non-rotationally symmetrical workpiece shapes, such as external workpiece shapes with flat surfaces.

[0020] With the method according to the invention, an outer workpiece shape of a workpiece can be produced which extends over the entire outer circumference of the workpiece and has an extension in the axial direction relative to the longitudinal axis of the workpiece. During this machining, the workpiece remains clamped in the workpiece fixture. The process is fast and precise.

[0021] A significant advantage of the method according to the invention is that, with focused laser light, the focal point during laser processing is always located at the position to be processed or very close to it. This allows for optimal processing of the workpiece.

[0022] According to another preferred embodiment of the present invention, the laser beam is directed along the laser path from A to B and then from B to A. This movement can be repeated as needed until a predetermined workpiece shape is formed on the workpiece.

[0023] According to another preferred embodiment of the present invention, the laser beam moves multiple times along the laser path from A to B, wherein the laser beam moves only in the direction from A to B and does not return. In order to make the laser beam return to point A after reaching point B, the laser beam can be turned off during the return process, or the laser beam can be activated along a curve when returning, which deviates from the laser path AB predetermined by the contour of the workpiece to be processed, wherein the curve extends outside the workpiece to be processed to avoid unnecessary interaction between the laser beam and the workpiece.

[0024] According to another preferred embodiment of the invention, the laser beam moves substantially perpendicularly to the beam axis of the laser beam during the second movement along the laser path from A to B. Thus, the movement direction of the laser beam during the second movement is substantially perpendicular to the beam axis of the laser beam.

[0025] According to another preferred embodiment of the present invention, a first point A and a second point B in the axial direction relative to the longitudinal axis of the workpiece indicate the boundaries of the three-dimensional outer workpiece shape to be processed. The laser processing extends along the axial direction between the boundary of points A and B.

[0026] According to another preferred embodiment of the present invention, the laser beam also performs a fourth movement, in which the laser beam moves around the center in an open or closed curve. The fourth movement is superimposed on the second movement. The center of the fourth movement is located on a curve determined by the shape of the contour of the workpiece to be processed. The diameter of the laser beam can be regarded as an offset. Then, the laser beam moves from a first point A to a second point B along the contour of the workpiece to be processed according to the second movement, and at the same time is guided along a small closed or open curve according to the fourth movement. The laser beam is not only guided along a straight line, a curve or a line of irregular shape corresponding to the contour of the workpiece to be processed, but also performs a circular movement around the contour of the workpiece to be processed by the fourth movement. This allows the area where material is removed from the workpiece when the laser beam hits the workpiece to be expanded. The range of the open curve or closed curve is small compared to the range of the contour of the workpiece to be processed. The closed curve can be, for example, in the shape of a circle, an ellipse or a figure 8. The open curve is characterized by the fact that the starting point and the end point of the curve do not coincide.

[0027] According to another preferred embodiment of the invention, the ratio between the diameter of the open or closed curve and the diameter when the laser beam hits the workpiece is between 1.2 and 150. This ensures that the extent of the open or closed curve is smaller than the contour of the workpiece to be machined. The curve preferably has a diameter between 0.05 mm and 2.0 mm. The diameter when the laser beam hits the workpiece is preferably between 0.008 mm and 0.03 mm, particularly preferably between 0.015 mm and 0.03 mm.

[0028] According to another preferred embodiment of the present invention, during the third movement, the workpiece holding device is moved in a direction perpendicular to the beam axis of the laser beam.

[0029] According to a further preferred embodiment of the invention, during the third movement the workpiece holding device is moved perpendicularly to the geometric longitudinal axis of the workpiece.

[0030] According to a further preferred embodiment of the invention, during the third movement the laser beam is moved in the direction of the geometrical longitudinal axis of the workpiece.

[0031] According to another preferred embodiment of the invention, the third movement comprises a linear movement in a radial direction relative to the longitudinal axis of the workpiece.

[0032] According to another preferred embodiment of the present invention, the third movement comprises a linear movement in an axial direction or parallel to the axial direction relative to the longitudinal axis of the workpiece. The third movement may comprise a superposition of a radial movement and an axial movement relative to the longitudinal axis of the workpiece.

[0033] According to another preferred embodiment of the invention, when removing material from the surface of the workpiece, the laser beam is aligned with its beam axis parallel to a radial direction relative to the geometric longitudinal axis of the workpiece. The feed movement of the third movement is such that the focus of the laser beam is either on the surface of the workpiece, on the contour of the workpiece to be machined, or close to one of these points.

[0034] According to another preferred embodiment of the present invention, the laser beam is tilted in the axial direction at an angle α with its beam axis relative to the tangent of the surface of the workpiece shape to be processed, wherein the angle α is between 1° and 10°. It can be tilted at an angle α relative to the tangent in any direction. The tangent of the surface forms a plane together with the beam axis. The plane can be, for example, perpendicular to the geometric longitudinal axis of the workpiece or parallel to the geometric longitudinal axis of the workpiece. In addition, the plane can have any other orientation relative to the longitudinal geometric axis of the workpiece.

[0035] According to another preferred embodiment of the present invention, the third movement is controlled according to the second movement.

[0036] According to another preferred embodiment of the present invention, the third movement is controlled according to the first movement.

[0037] According to another preferred embodiment of the invention, material is removed in the axial portion between points A and B along the entire circumference of the workpiece.

[0038] According to another preferred embodiment, the workpiece is rotated at a constant speed during the entire material removal period. Alternatively, the rotation speed can be changed according to the second and third movements and / or according to the shape of the workpiece to be processed.

[0039] According to another preferred embodiment of the present invention, the workpiece arranged in the workpiece fixture is rotated at a rotational speed between 5 rpm and 1,000 rpm. The rotational speed can remain constant throughout the entire machining process or vary depending on the workpiece and / or the shape of the workpiece to be machined. For rotationally symmetrical workpieces, for example, a constant rotational speed between 50 and 300 rpm can be set. However, this is not mandatory. The rotational speed can also be adjusted according to the diameter of the workpiece. For example, if the diameter of the workpiece is rotationally symmetrical, the rotational speed can be lower at the beginning as long as the laser beam has not yet contacted the surface of the workpiece. Once the laser beam approaches the surface of the workpiece, the rotational speed can be increased. This affects the amount of material removed from the surface of the workpiece. For example, by changing and adjusting the rotational speed, it is possible to achieve the removal of the same amount of material at predetermined time intervals, even if the diameter of the workpiece changes due to material removal.

[0040] According to another preferred embodiment of the present invention, in the second movement showing the guiding of the laser beam, the laser beam moves at a speed between 0.05 m / s and 10 m / s.

[0041] According to another preferred embodiment of the present invention, the third movement, in which the workpiece fixture and / or the laser beam are moved toward each other, is performed at a speed between 0.05 mm / min and 500 mm / min.

[0042] According to a further preferred embodiment of the invention, the direction of rotation of the workpiece holding device is changed during the laser processing of the workpiece.

[0043] The laser processing device for performing the method according to the present invention is characterized in that it includes: a workpiece fixture for accommodating and fixing the workpiece, a moving device for moving the workpiece fixture relative to the device base, and a laser for generating a laser beam guided along the beam axis, and the laser has a laser deflection device specifically for deflecting the laser beam. The moving device is designed to perform a workpiece rotation movement on the workpiece arranged in the workpiece fixture. This movement is called the first movement. The laser deflection device is designed to guide the laser beam so that the laser beam moves along a predetermined laser path, which extends from a first point A to a second point B, and the laser path is predetermined by the route of the contour of the workpiece to be processed. This movement is called the second movement. The moving device and / or the laser performs a feed movement so that the surface of the workpiece arranged in the workpiece fixture contacts the laser beam, the laser beam removes material from the surface of the workpiece, and generates a predetermined outer workpiece contour. This feed movement is called the third movement. The laser processing device is designed so that the first movement, the second movement and the third movement are performed simultaneously and cooperate with each other.

[0044] According to another preferred embodiment of the invention, the laser processing device is equipped with a control device for controlling the first movement, the second movement and the third movement. This ensures that the three movements are coordinated with each other. If the laser beam performs an additional fourth movement, the control device advantageously also controls the fourth movement.

[0045] Further advantages and advantageous developments of the invention can be found in the following description, the drawings and the claims.

[0046] Attached photos

[0047] The drawings illustrate embodiments of laser-based processing of a workpiece according to the invention.

[0048] in:

[0049] Figure 1 is the first embodiment of laser-based workpiece processing,

[0050] Figure 2 is in accordance with Figure 1 The workpiece begins processing.

[0051] Figure 3 is based on Figure 1 The workpiece is processed at different times.

[0052] Figure 4 It means according to Figures 1 to 3 The alignment of the laser beam during processing and the direction of movement of the third movement are indicated.

[0053] Figure 5 It means according to Figures 1 to 3 Alternative alignments of the laser beam during processing and indication of the movement direction of the third movement,

[0054] Figure 6 It means according to Figure 4 The alignment of the laser beam during the machining process and the alternative movement direction of the third movement,

[0055] Figure 7 is a representation of the second and fourth movements associated with the laser beam,

[0056] Figure 8 is a representation of the second and alternative fourth movement associated with the laser beam,

[0057] Figure 9a This is a perspective view of a workpiece in a relatively early state of laser processing.

[0058] Figure 9b The workpiece is based on Figure 9a Front view of the state,

[0059] Fig.10a This is a perspective view of the workpiece at the end of laser processing.

[0060] Fig.10b The workpiece is based on Fig.10a Front view of the state,

[0061] Fig.11 It is a perspective view of the workpiece and a front view at different times of laser processing.

[0062] Fig.12 is the workpiece and the laser beam, where the laser beam is at different positions along the laser path,

[0063] Fig.13 is a second embodiment of laser-based workpiece processing,

[0064] Figures 13a to 13n The workpiece and the laser beam at different processing times during laser processing according to the second embodiment,

[0065] Fig.14 is a laser-based workpiece processing, not an embodiment according to the present invention,

[0066] Fig.15 is based on Fig.14 Laser processing of the workpiece before the laser processing begins,

[0067] Fig.16 is based on Fig.14 Laser processing of the workpiece at the beginning of laser processing,

[0068] Fig.17 is based on Fig.14 Workpiece during laser processing,

[0069] Fig.18 is based on Fig.14 The workpiece after laser processing,

[0070] Fig.19 This is a perspective view of the laser processing device at the end of laser processing. DETAILED DESCRIPTION

[0071] Figures 1 to 12 A first method for laser-based machining of a workpiece 4 using a laser beam 2 is shown. The workpiece 4 is initially provided as a blank. The blank has the shape of a cylinder. The workpiece 4 is clamped in a workpiece fixture of a laser machining device. Fig.19 A laser processing device 50 is shown having a workpiece fixture 51, a moving device 53 and a laser 56. The moving device moves the workpiece fixture relative to the device base 55. The movement comprises in particular a rotation of the workpiece fixture 51 together with the workpiece 4 or 54 accommodated in the workpiece fixture 51 around a geometric axis coinciding with the geometric workpiece longitudinal axis 5. The workpiece longitudinal axis 5 extends through the workpiece 4. It is therefore an axis of rotation constrained by the workpiece. In the present case, the workpiece 4 has the shape of a cylinder before laser processing. This is rotationally symmetrical with respect to the geometric workpiece longitudinal axis 5. When rotating around the workpiece longitudinal axis 5, the workpiece 4 performs a continuous complete rotation cycle. This movement is referred to as the first movement. Figures 2 to 6 This is shown by the circular arrow on the right side of the workpiece 4.

[0072] By laser processing, an outer workpiece shape with a workpiece contour 1 is to be created on the workpiece. Figures 1 to 12 In the exemplary embodiment, the workpiece shape to be created is rotationally symmetric with respect to the geometric workpiece longitudinal axis 5 .

[0073] The laser beam 2 having a geometrical beam axis 2a is given by Fig.19 The laser 56 shown generates Fig.19 The laser deflection device shown is guided along the workpiece contour 1. This movement of the laser beam is called the second movement. The laser path 3 is specified by the workpiece contour 1. It 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 geometric workpiece plane 8, as Figure 9a , 9b, 10a and 10b. This takes into account that the laser beam 2 on the workpiece 4 can not only remove material at the middle point of the laser beam, but also remove material in a circular area.

[0074] During laser processing, the laser beam 2 is moved a number of times along the laser path between points A and B until enough material has been removed from the workpiece 4 by the laser beam 2 to produce a predetermined outer workpiece shape. The laser beam can move back and forth between points A and B. Or the laser beam can be directed in only one direction, from A to B or from B to A. The number of cycles that the laser beam 2 must be directed along the laser path 3 depends on the type and amount of material to be removed and the laser.

[0075] The laser is preferably a pulsed laser. Short laser pulses produce a high energy density on the surface of the workpiece without causing unwanted heat to enter the workpiece. The duration of the laser pulses is preferably in the picosecond or femtosecond range.

[0076] By the feed movement of the workpiece fixture and / or the laser beam, the surface of the workpiece 4 set in the workpiece fixture is brought into contact with the laser beam 2, and the material placed on the surface of the workpiece 4 is removed using the laser beam 2, gradually creating the workpiece contour 1. This feed movement is called the third movement. Figures 1 to 6 In this case, the feed movement is a linear displacement of the workpiece 4 perpendicular to the geometrical workpiece longitudinal axis 5 and having a movement direction 6 . Figure 6 Also shown is a displacement of the laser path 3 in the direction of the geometric workpiece longitudinal axis 5. This is a parallel displacement of the laser path 3 in the direction indicated by the arrow.

[0077] The first movement, the second movement and the third movement are performed simultaneously. They are superimposed on each other. The laser beam 2 is used to remove material from the surface of the workpiece 4, wherein a predetermined workpiece shape of the workpiece 4 is gradually generated. Figure 3 In the first embodiment, Figure 1 , Figure 4 , Figure 5 and Figure 6 The laser beam 2 shown is first Figure 2 The contact point 7 shown is in contact with the workpiece 4. This contact point 7 coincides with the first point A of the laser path 3.

[0078] The laser beam 2 can be aligned with its beam axis 2a perpendicular to a workpiece plane 8. The workpiece plane 8 is a geometrical plane extending through the workpiece. The geometrical workpiece longitudinal axis 5 extends in the workpiece plane. Figure 9a , 9b , 10a and 10b. In principle, there are any number of workpiece planes that extend through the workpiece 4 and in which the workpiece longitudinal axis 5 extends. All planes that meet these conditions intersect the longitudinal axis 5 of the workpiece. Figure 9a , 9bA special feature of the workpiece plane 8 shown in FIGS. 10a and 10b is that the laser beam 2 is perpendicular to the workpiece plane 8. The vertical alignment of the laser beam 2 is as follows: Figure 4 , 6 , 9a, 9b, 10a and 10b. If the laser beam 2 is aligned perpendicular to the workpiece plane 8, the laser beam 2 extends tangentially to the surface of the workpiece 4 during material removal. Alternatively, the laser beam 2 can be inclined at an angle α relative to one of these perpendicular orientations. A straight line perpendicular to the workpiece plane 8 is also referred to as a normal. The beam axis 2a of the laser beam 2 either extends perpendicular to the workpiece plane 8 or forms an angle of maximum 10° with the normal to the workpiece plane 8. The laser beam 2 and the workpiece 4 are in contact with each other in such a way that the laser beam 2 is aligned tangentially to the surface of the rotating workpiece or forms an angle of maximum 10° with a tangent to the workpiece surface, as shown in FIG. Figure 5 The figure shows that the beam axis 2a of the laser beam 2 can be aligned in different directions relative to the tangent to the workpiece surface at the point to be processed. The laser focus 9 is advantageously located close to the surface of the workpiece 4. Figure 5 Examples of four different directions in which the laser beam 2 can be tilted with its beam axis are shown. The beam axis of the laser beam 2 and the tangent to the point to be processed on the surface of the workpiece 4 extend at angles α1 and α2 in a plane parallel to the longitudinal axis 5 of the workpiece. The beam axis of the laser beam 2 and the tangent to the point to be processed on the surface of the workpiece 4 extend at angles α3 and α4 in a plane perpendicular to the longitudinal axis 5 of the workpiece. However, the laser beam can be tilted at an angle α in any other direction. The angles α, α1, α2, α3, α4 between the beam axis of the laser beam 2 and the tangent to the shape of the workpiece to be processed are between 1° and 10°.

[0079] The additional movement of the laser beam 2 is as follows Figure 7 and 8 This is referred to as the fourth movement. When the laser beam 2 is directed along the laser path 3, the laser beam 2 also moves along the closed circular curve 10 or the irregular shape curve 11.

[0080] exist Figure 9a , 9b , 10a, 10b, 11 and 12, the workpiece 4 and the laser beam 2 are shown in different views at different times during the laser processing. The figure shows that the focus 9 of the laser beam 2 is directly on the surface of the workpiece 4. Fig.11 Also shown is the appearance of the workpiece 4 at various portions processed by the laser. Fig.12 It is shown how the laser beam 2 is guided relative to the workpiece 4 during the second movement and thereby moves along the predetermined laser path 3 . Fig.12 The first illustration in shows the laser beam 2 at a first point A. Fig.12 The last diagram in FIG shows the laser beam 2 at a second point B. Fig.12In the last illustration of the laser process, the laser process is complete. The workpiece now has the three-dimensional outer shape to be processed. Fig.10a and Fig.11 The penultimate figure of FIG. 1 also shows the shape of the outer workpiece to be processed. The predetermined shape of the outer workpiece has different cross sections in different axial sections. The predetermined shape of the outer workpiece is rotationally symmetrical as a whole. Fig.12 The remaining illustrations in show the laser beam 2 at positions on the laser path 3 between points A and B.

[0081] exist Figure 9a and 10a In FIG. 1 , the laser path 3 is shown as the intersection between the geometric workpiece plane 8 and the outer workpiece shape to be machined.

[0082] Fig.13 and Figures 13a to 13n A second embodiment of laser processing is shown in FIG. Figures 1 to 12 The difference from the first embodiment is that the workpiece 24 has an outer workpiece shape 21 to be machined comprising a flat surface. When the laser machining is completed, the machined cross-section of the workpiece 24 has a hexagonal cross-section of different sizes. Therefore, the workpiece shape to be machined is not rotationally symmetrical. The outer workpiece shape is produced by superimposing a first movement, i.e. a rotation of the workpiece 24 around a geometric workpiece longitudinal axis 25, and a second movement, the second movement involving guiding the laser beam along a laser path between two points A and B predetermined by the workpiece shape 21 to be machined, and by a third movement in the form of a feed movement in a direction 26. The laser beam 22 is aligned with its beam axis 22a perpendicular to a workpiece plane 28, in which the geometric workpiece longitudinal axis 25 extends. The workpiece plane is as shown in FIG. Fig.13b As shown, points A and B represent the boundaries of the workpiece contour in the axial direction, which are offset in the axial direction relative to the geometric workpiece longitudinal axis 25. They are also offset in the radial direction.

[0083] Figures 13a to 13n Shown according to Fig.13 An axial cross-section of a workpiece 24 showing various stages of material removal and the associated alignment of the laser beam 22 relative to the workpiece 24 . Fig.13c , 13e The arrows 26 in 13g, 13i, 13k and 13m show how the feed motion, referred to as the third motion, interacts with the rotational motion, referred to as the first motion, of the workpiece 24 about its geometric workpiece longitudinal axis 25 and is coordinated with the position of the laser beam 22 along the laser path between points A and B to produce a predetermined angular cross section related to the associated axial cross section. The workpiece shape 21 can be machined on a cylindrical workpiece, such as Figure 1 shown. Fig.13b , 13d, 13f, 13h, 13j, 131 and 13n show that the orientation of the laser beam 22 relative to the workpiece plane 28 does not change during laser processing.

[0084] Figures 14 to 18 An embodiment of laser treatment not according to the invention is shown. Figures 1 to 12 The first embodiment differs from the first embodiment in that, during material removal, the laser beam 32 is aligned with its beam axis radially with a geometrical workpiece longitudinal axis 35 of the workpiece 34. The laser beam 32 is guided along a laser path 33 which is predetermined by the workpiece contour 31 of the workpiece 34 to be machined. The feed movement according to the third shift takes place in a direction 36. Fig.15 34 and the laser beam 32 are shown before laser processing begins. At this stage, the workpiece has the shape of a cylinder. Fig.16 Start. Due to the feed movement of the third shift, the workpiece 34 is moved towards the laser beam 32 so that the focus 39 is located in the region of the workpiece contour 31 to be machined. The arrow 40 indicates the rotation of the workpiece 34 about the workpiece longitudinal axis 35 according to the first shift. Fig.17 The workpiece 34 is shown after some material has been removed from the outside. Fig.18 Shows the finished workpiece at the end of laser processing.

[0085] Fig.19 A laser processing device 50 for performing the method is shown. The laser processing device 50 comprises: a workpiece fixture 51, which accommodates and fixes a workpiece 54; a moving device 53, which moves the workpiece 54 arranged in the fixture relative to the device base 55; a laser 56, which generates a laser beam 52; and a laser deflection device 57 that guides the laser beam 52. In the present case, the moving device 53 has three linear axes X, Y, Z and two rotation axes B and C. The rotation axis C rotates the workpiece 54 arranged in the workpiece fixture 51 around a geometric 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. Here, the laser beam 52 is along a Fig.19 The laser path (not shown) is moved relative to the workpiece 54. For this purpose, the laser deflection device 57 comprises a plurality of mirrors that can deflect the laser beam in a targeted manner. In addition, the laser deflection device is equipped with at least one lens that focuses the laser beam onto the surface of the workpiece 54. The mirrors and lenses are not shown in the figure.

[0086] All features are essential to the invention either individually or in any combination with one another.

[0087] Reference Mark

[0088] 1. Contour of workpiece to be processed

[0089] 2 Laser beams

[0090] 2a Beam axis

[0091] 3 Laser Paths

[0092] 4 Workpiece

[0093] 5Longitudinal axis of workpiece

[0094] 6 The moving direction of the workpiece during the third movement

[0095] 7 The contact point between the laser beam and the workpiece at the beginning of laser processing

[0096] 8 Workpiece plane

[0097] 9 Laser Focus

[0098] 10 Closed curve when moving the laser beam according to the fourth movement

[0099] 11 Open curve when moving the laser beam according to the fourth movement

[0100] 21 Shape of workpiece to be processed

[0101] 22 Laser Beam

[0102] 22a beam axis

[0103] 24 Workpiece

[0104] 25 Workpiece longitudinal axis

[0105] 26 Feed motion direction

[0106] 28 Geometric workpiece plane

[0107] 31 Workpiece contour of the workpiece to be machined

[0108] 32 Laser Beam

[0109] 33 Laser Path

[0110] 34 Workpieces

[0111] 35 Workpiece longitudinal axis

[0112] 36 Feed motion direction

[0113] 39 Focus of laser beam

[0114] 40 Rotation according to the first move

[0115] 50 Laser processing equipment

[0116] 51 Workpiece Fixing Device

[0117] 52 Laser Beam

[0118] 53 Workpiece moving device

[0119] 54 Workpieces

[0120] 55 device base

[0121] 56 lasers

[0122] 57 Laser deflection device

Claims

1. A method for laser processing of an elongated workpiece (4, 24, 54) extending along a geometric workpiece longitudinal axis (5, 25), in, A laser machining device (50) is used to machine a predetermined three-dimensional external workpiece shape (21) having a contour (1) at the workpiece (4, 24, 54) by removing material with a laser beam (2, 52), wherein the workpiece contour (1) corresponds to the intersection of the three-dimensional external workpiece shape (21) to be machined and a geometric workpiece plane (8, 28) in which the geometric workpiece longitudinal axis (5, 25) extends, the workpiece contour (1) being located between a first point A and a second point B, wherein the workpiece contour (1) at the first point A is located between a first point A and a second point B. The laser processing device (50) extends between a point A and a second point B, and the points A and B are offset from each other at least in the axial direction, and comprises: a workpiece fixing device (51) for accommodating and fixing the workpiece (4, 24, 54), a moving device (53) for moving the workpiece fixing device relative to a device base (55), a laser (56) for generating a laser beam (2, 52) guided along a beam axis (2a, 22a), and a laser deflecting device (57) for deflecting the laser beam (2, 52); It is characterized by having the following method steps: - arranging a workpiece (4, 24, 54) in the workpiece fixture (51), -Perform the following three moves: The first movement is a workpiece rotation movement, wherein the workpiece fixture (51) is driven to rotate with the moving device (53), thereby driving the workpiece (4, 24, 54) arranged in the workpiece fixture (51) to rotate infinitely around the geometric workpiece longitudinal axis (5, 25) and perform a continuous complete rotation cycle, a second movement, namely the guiding of the laser beam (2, 52), wherein the laser beam (2, 52) is moved by means of the laser deflection device (57) along a predetermined laser path (3), which corresponds to the workpiece contour (1) between points A and B, wherein the laser beam (2, 22) is aligned perpendicularly to the geometric workpiece plane (8, 28) or forms an angle of at most 10° with the normal to the geometric workpiece plane (8, 28), wherein the laser beam (2, 52) is guided a plurality of times along the laser path (3) between points A and B during the second movement, a third movement, which is a feed movement, wherein the workpiece fixture (51) and / or the laser beam (2, 52) are advanced, wherein a surface of a workpiece (4, 24) arranged in the workpiece fixture (51) is brought into contact with the laser beam (2, 52) such that the laser beam is tangentially aligned with the surface of the workpiece (4, 24, 54) or forms an angle of up to 10° with a tangent to the surface of the workpiece (4, 24, 54), wherein the laser beam (2, 52) is used to remove material from the surface of the workpiece (4, 24, 54) and to machine a predetermined three-dimensional outer workpiece shape (21) having a workpiece contour (1, 21), The first movement, the second movement and the third movement are performed simultaneously and parallel to each other until a predetermined workpiece shape (21) having a workpiece contour (1) is formed on the workpiece (4, 24, 54).

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

3. The method according to any one of the preceding claims, It is characterized in that During a second movement along the laser path (3) from A to B, the laser beam (2, 52) moves perpendicularly to the beam axis.

4. The method according to any one of the preceding claims, It is characterized in that Relative to the geometric workpiece longitudinal axis (5, 25), a first point A and a second point B in the axial direction illustrate the boundaries of the outer workpiece shape (4, 24, 54) to be machined using the method.

5. The method according to any one of the preceding claims, It is characterized in that The laser beam (2, 52) performs an additional fourth movement, wherein the laser beam (2, 52) moves in an open curve or a closed curve around the center, and the fourth movement is superimposed on the second movement.

6. The method according to claim 5, It is characterized in that The ratio between the diameter of the open or closed curve and the diameter of the laser beam (2, 52) when impinging the workpiece (4, 24, 54) is between 1.2 and 150.

7. The method according to any one of the preceding claims, It is characterized in that During the third movement, the workpiece holding device (51) moves in a direction perpendicular to the beam axis of the laser beam (2, 52).

8. The method according to any one of the preceding claims, It is characterized in that During the third movement, the laser beam (2, 52) moves in a direction toward the workpiece (4, 24, 54).

9. The method according to any one of the preceding claims, It is characterized in that The third movement comprises a linear movement in a radial direction relative to the longitudinal axis (5, 25) of the geometric workpiece.

10. The method according to any one of the preceding claims, It is characterized in that The third movement comprises a linear movement in an axial direction relative to the longitudinal axis (5, 25) of the geometric workpiece or parallel to the axial direction.

11. The method according to any one of the preceding claims, It is characterized in that When removing material from the surface of the workpiece (4, 24), the laser beam (2, 22) is aligned with its beam axis parallel to a radial direction relative to a longitudinal axis (5, 25) of the geometric workpiece.

12. The method according to any one of the preceding claims, It is characterized in that The laser beam (2, 52) is tilted with its beam axis in the axial direction at an angle α relative to a tangent to the surface of the workpiece (4, 24, 54), wherein the angle α is between 1° and 10°.

13. The method according to any one of the preceding claims, It is characterized in that The third movement is controlled according to the second movement.

14. The method according to any one of the preceding claims, It is characterized in that The third movement is controlled according to the first movement.

15. The method according to any one of the preceding claims, It is characterized in that Material is removed in the axial portion between points A and B along the entire circumference of the workpiece (4, 24, 54).

16. A method according to any one of the preceding claims, It is characterized in that During the entire material removal process, the workpiece rotation movement takes place at a constant speed.

17. A laser processing device for carrying out the method according to any one of the preceding claims, It is characterized in that It has a workpiece fixture (51) for accommodating and fixing a workpiece (4, 24, 54), a moving device (53) for moving the workpiece fixture (51) relative to a device base (55), and includes a laser (56) which generates a laser beam (2, 22, 52) guided along a beam axis (2a, 22a) and has a laser deflection device (57) specifically for deflecting the laser beam (2, 22, 52). wherein the movement device (53) is designed to perform a first movement, which is a workpiece rotation movement, wherein the workpiece fixture (51) is rotated and an elongated workpiece (4, 24, 54) arranged in the workpiece fixture (51) is infinitely rotated about its geometric workpiece longitudinal axis (5, 25) and performs a continuous complete rotation cycle, wherein the laser deflection device (57) is designed to guide the laser beam (2, 52) in a second movement and thereby move the laser beam (2, 22, 52) along a predetermined laser path (3), wherein the laser path (3) extends from a first point A to a second point B and the laser path (3) is predetermined by the course of a workpiece contour (1) of the three-dimensional external workpiece shape (21) to be machined, wherein the moving device (53) and / or the laser (56) is designed to perform a feed movement as a third movement so that the surface of a workpiece (4, 24, 54) arranged in the workpiece fixture (51) comes into contact with the laser beam (2, 22, 52), wherein the laser beam (2, 22, 52) is used to remove material from the surface of the workpiece (4, 24, 54) and to machine a predetermined outer workpiece shape (21) having a workpiece contour (1), The first movement, the second movement and the third movement are performed simultaneously.

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

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