Laser processing head and laser machine

Abstract

A laser processing head (1A) comprises: a first lens group (11) into which laser light emanating from a light emitter (3) enters and is focused; a second lens group (12) to which the laser light, having passed through the first lens group (11), propagates; a third lens group (13) which, together with the second lens group (12), forms a lens group into which the laser light, having passed through the second lens group (12), propagates and which forms an image of the light emitter (3) at a transfer position; a fourth lens group (14) into which the laser light, having passed through the third lens group (13), enters and is focused; an optical light-flux conversion element (15) which is arranged along an optical axis between the first lens group (11) and the second lens group (12) and converts a beam profile of the laser light;a first moving device (17) which moves the first lens group (11) in a direction along the optical axis; and a second moving device (18) which moves the third lens group (13) in a direction along the optical axis.

Description

Technical area

[0001] The present disclosure relates to a laser processing head that emits laser light and a laser machine. Technological background

[0002] In laser processing, high-quality processing or high-efficiency processing is expected on workpieces of different materials or thicknesses. Therefore, the laser machine requires appropriate control of the beam diameter of the laser beam at the condensing position or the beam mode, which is the intensity distribution of the laser beam in a cross-section of the laser beam. When processing a medium-thickness plate, it is necessary to shape the laser beam with a high intensity at the outer edge portion of the laser beam, that is, to form a so-called annular beam profile, and to increase the beam diameter.

[0003] Patent Literature 1 discloses a laser processing machine including two axicon lenses and a moving mechanism that moves each axicon lens in the optical axis direction (optical axis direction), in which the laser processing machine switches a beam profile by changing the distance between the axicon lenses. In the laser processing machine according to Patent Literature 1, laser light emitted from a light emitter passes through the two axicon lenses and a condenser lens in a laser processing head and is condensed so that an image transfer position of the light emitter is located on or near a surface of the workpiece. Citation listPatent literature

[0004] Patent Literature 1: Japanese Patent Application Laid-Open No. 2019 - 42 793 Brief description of the inventionProblem to be solved by the invention

[0005] According to the technique described in Patent Literature 1, an annular beam profile is obtained at a position spaced apart from the transfer position in the optical axis direction, but the annular beam profile is not obtained at the transfer position. Further, according to the technique described in Patent Literature 1, in order to increase a beam diameter in the annular beam profile, it is necessary to shift a position of the workpiece far from the transfer position. By shifting the position of the workpiece far from the transfer position, an edge of the laser beam on the workpiece becomes blurred, so that the machining quality is deteriorated. For this reason, the conventional technique described in Patent Literature 1 has a problem that it is difficult to achieve high-quality machining by converting the beam profile.

[0006] The present disclosure has been made in view of the foregoing, and it is an object of the present disclosure to obtain a laser processing head that can achieve high-quality processing by converting the beam profile. Means to solve the problem

[0007] In order to solve the above problems and achieve the object, a laser processing head according to the present disclosure comprises: a first lens group into which laser light diverging from a light emitter enters and which is configured to condense the laser light; a second lens group to which the laser light that has passed through the first lens group propagates; a third lens group for forming, together with the second lens group, a lens group configured to form an image of the light emitter at the transfer position, the laser light that has passed through the second lens group propagated to the lens group; a fourth lens group into which the laser light that has passed through the third lens group enters and which is configured to condense the laser light; a luminous flux conversion optical element (FEC).light flux conversion optical element) arranged along an optical axis between the first lens group and the second lens group and configured to convert a beam profile of the laser light; a first moving device configured to move the first lens group in a direction along the optical axis; and a second moving device configured to move the third lens group in a direction along the optical axis. Effects of the invention

[0008] A laser processing head according to the present disclosure has an effect of achieving high-quality processing by beam profile conversion. Short description of the drawings Fig. 1 is a diagram illustrating an exemplary configuration of a laser processing head according to a first embodiment. Fig. 2 is a diagram for explaining an operation of the laser processing head according to the first embodiment. Fig. 3 is a diagram illustrating a configuration of the laser processing head according to the first embodiment, and a configuration according to a first comparative example of the first embodiment. Fig. 4 is a diagram illustrating a configuration according to a second comparative example of the first embodiment. Fig. 5 is a diagram illustrating an example in which a distance from a light emitter to a transfer position is changed by the laser processing head according to the first embodiment. Fig. 6 is a diagram illustrating an exemplary configuration of a laser processing head according to a second embodiment. Fig. 7 is a first diagram for explaining an operation of the laser processing head according to the second embodiment. Fig. 8 is a second diagram for explaining an operation of the laser processing head according to the second embodiment. Fig. 9 is a diagram illustrating an exemplary configuration of a laser machine according to a third embodiment. Fig. 10 is a diagram illustrating an exemplary configuration of a control circuit according to the first or second embodiment. Fig. 11 is a diagram illustrating an exemplary configuration of a dedicated hardware circuit according to the first or second embodiment. Description of embodiments

[0009] Hereinafter, a laser processing head and a laser machine according to embodiments will be described in detail with reference to the drawings. First embodiment.

[0010] Fig. 1 is a diagram illustrating an exemplary configuration of a laser processing head 1A according to a first embodiment. The laser processing head 1A is provided in a laser machine. The laser processing head 1A emits a laser beam toward a workpiece 5. The workpiece 5 is a metal plate. A metal material such as iron, stainless steel, or brass is used as a material of the workpiece 5. Note that a material of the workpiece 5 and a shape of the workpiece 5 are not limited to those described in the first embodiment.

[0011] A transmission line 2 is a transmission path for laser light from a light source to the laser processing head 1A. The transmission line 2 is, for example, a light guide. Fig. 1, an illustration of the light source is omitted. The laser processing head 1A includes a housing 16, which forms an outer shell of the laser processing head 1A. Fig. Figure 1 schematically illustrates configurations housed in the housing 16. A light emitter 3, which is an emitting end of the transmission line 2, is connected to an interior of the housing 16. Laser light propagated through the transmission line 2 enters the housing 16.

[0012] The laser processing head 1A includes a first lens group 11; a second lens group 12; a third lens group 13; a fourth lens group 14; and a luminous flux conversion optical element 15. The first lens group 11, the second lens group 12, the third lens group 13, the fourth lens group 14, and the luminous flux conversion optical element 15 are housed in the housing 16. The first lens group 11, the second lens group 12, the third lens group 13, and the fourth lens group 14 constitute an optical transfer system 10 that transfers an image of the light emitter 3. When the luminous flux conversion optical element 15 exists along an optical axis, the luminous flux conversion optical element 15 is also included in the components of the optical transfer system 10.

[0013] The first lens group 11 is a lens group with positive refractive power. Laser light diverging from the light emitter 3 enters the first lens group 11 and is collimated. The second lens group 12 is a lens group with positive refractive power. Laser light that has passed through the first lens group 11 propagates to the second lens group 12.

[0014] The third lens group 13 is a lens group with negative refractive power. Laser light that has passed through the second lens group 12 propagates to the third lens group 13. The second lens group 12 and the third lens group 13 form a lens group that forms an image of the light emitter 3 at a transfer position. The fourth lens group 14 is a lens group with positive refractive power. Laser light that has passed through the third lens group 13 enters the fourth lens group 14 and is collimated. Laser light that has passed through the fourth lens group 14 is emitted outside the housing 16.

[0015] The luminous flux conversion optical element 15 is arranged along an optical axis between the first lens group 11 and the second lens group 12. In the first embodiment, the optical axis is an optical axis of the transfer optical system 10. The luminous flux conversion optical element 15 converts a beam profile of laser light. In the first embodiment, the luminous flux conversion optical element 15 is an axicon lens. The axicon lens includes a conical surface, which is a conical-convex surface, and a flat surface on a side opposite the conical surface. The luminous flux conversion optical element 15 converts a Gaussian beam into an annular beam. By arranging the luminous flux conversion optical element 15 along the optical axis, the laser processing head 1A generates an annular beam profile at the transfer position or in the vicinity of the transfer position. Fig. In the example shown in Figure 1, it is assumed that the transfer position coincides with a position on the workpiece 5.

[0016] The laser processing head 1A includes a first moving device 17 and a second moving device 18. The first moving device 17 moves the first lens group 11 in a direction along the optical axis. The second moving device 18 moves the third lens group 13 in the direction along the optical axis.

[0017] A controller 4 controls the entire laser machine, including the laser processing head 1A. The controller 4 transmits a control signal to both the first moving device 17 and the second moving device 18. The first moving device 17 moves the first lens group 11 in response to the control signal. The second moving device 18 moves the third lens group 13 in response to the control signal. The controller 4 controls the first moving device 17 and the second moving device 18 by sending a control signal to each of the first moving device 17 and the second moving device 18.

[0018] In Fig. 1, each of the first lens group 11, the second lens group 12, the third lens group 13, and the fourth lens group 14 is illustrated as a single lens. However, each of the first lens group 11, the second lens group 12, the third lens group 13, and the fourth lens group 14 is not limited to a single lens and may include multiple lenses. The number of lenses in each of the first lens group 11, the second lens group 12, the third lens group 13, and the fourth lens group 14 can be any number.

[0019] Next, an operation of the laser processing head 1A when converting a beam profile of the laser beam emitted from the laser processing head 1A will be described.

[0020] Fig. 2 is a diagram for explaining an operation of the laser processing head 1A according to the first embodiment. Fig. 2 shows a state in which each of the first lens group 11 and the third lens group 13 is moved in the direction of the optical axis. In Fig. 2, a main configuration of the laser processing head 1A is illustrated, and illustration of other configurations of the laser processing head 1A is omitted.

[0021] Here, a reference is made to a section in the left part of Fig. 2 is referred to as a first state. In addition, a state shown in a right part of Fig. 2 is referred to as a second state. In the first state, the first lens group 11 is moved toward the light emitter 3, and the third lens group 13 is moved toward the fourth lens group 14. That is, the first state is a state in which the first lens group 11 and the third lens group 13 have moved in directions away from each other. In contrast, in the second state, the first lens group 11 is moved toward the second lens group 12, and the third lens group 13 is moved toward the second lens group 12. That is, the second state is a state in which the first lens group 11 and the third lens group 13 have moved in directions in which they approach each other.The state of the laser processing head 1A is switched between the first state and the second state by moving the first lens group 11, which is caused by the first moving device 17, and moving the third lens group 13, which is caused by the second moving device 18. A in . Fig. The double arrow shown in Fig. 2 indicates that the state of the laser processing head 1A can be switched between the first state and the second state.

[0022] A beam profile (English: beam mode) 21 is a beam profile in which the laser processing head 1A is in the first state. A beam profile 22 is a beam profile when the laser processing head 1A is in the second state. Each of the beam profiles 21 and 22 is an annular beam profile. A beam diameter in the beam profile 21 is larger than a beam diameter in the beam profile 22. Note that the beam diameter of the annular laser beam is referred to as a ring diameter in the following description.

[0023] When the laser processing head 1A is in the second state, the state of the laser processing head 1A is switched to the first state by moving the first lens group 11 and the third lens group 13 in directions away from each other in a state in which image formation of an image of the light emitter 3 at the transfer position is maintained. As a result, the laser processing head 1A increases the ring diameter from the beam profile 22 to the beam profile 21.

[0024] When the laser processing head 1A is in the first state, the state of the laser processing head 1A is switched to the second state by moving the first lens group 11 and the third lens group 13 in directions to approach each other in a state where image formation of an image of the light emitter 3 at the transfer position is maintained. As a result, the laser processing head 1A reduces the ring diameter from the beam profile 21 to the beam profile 22. In this way, the laser processing head 1A converts the beam profile of the laser beam while maintaining image formation of the image of the light emitter 3 at the transfer position.

[0025] A state of the laser processing head 1A can be switched between the first state and the second state depending on a material of the workpiece 5 or a thickness of the workpiece 5. For example, in laser processing of a medium-thickness plate having a thickness of approximately 20 mm, high-quality and high-efficiency processing can be performed by setting the laser processing head 1A to the first state. Since the laser processing head 1A can transform the beam profile while maintaining image formation of an image of the light emitter 3 at the transfer position, it is possible to perform high-quality processing compared to a case where it is necessary to shift a position of the workpiece far from the transfer position.The laser processing head 1A can select a beam diameter suitable for a processing target simply by moving the first lens group 11 and moving the third lens group 13. By appropriately selecting a beam diameter in accordance with a material of the workpiece 5 or a thickness of the workpiece 5, it is possible to improve processing quality and productivity.

[0026] Next, a functional effect of a configuration of the laser processing head 1A according to the first embodiment will be described. Here, a configuration according to a comparative example will be illustrated, and a functional effect achieved by the configuration of the laser processing head 1A will be described by comparing it with the case of the comparative example.

[0027] Fig. 3 is a diagram illustrating a configuration of a laser processing head 1A according to the first embodiment and a configuration according to a first comparative example of the first embodiment. A left part of Fig. 3 illustrates a configuration included in the laser processing head 1A according to the first embodiment. A right part of Fig. 3 illustrates a configuration according to the first comparative example. The configuration according to the first comparative example differs from the configuration of the first embodiment in that the luminous flux conversion optical element 15 is arranged between the light emitter 3 and the first lens group 11.

[0028] Also, in the configuration according to the first comparative example, the ring diameter can be changed by moving the first lens group 11 and the third lens group 13. When changing the ring diameter, the ring diameter can be made larger as a distance between the light emitter 3 and the luminous flux conversion optical element 15 becomes longer. In the case of the first comparative example, since the luminous flux conversion optical element 15 is arranged immediately after the light emitter 3, a distance between the light emitter 3 and the first lens group 11 becomes longer as the distance between the light emitter 3 and the luminous flux conversion optical element 15 becomes longer. As the distance between the light emitter 3 and the first lens group 11 becomes longer, it is necessary to increase a size of the optical system behind the first lens group 11 in order to capture laser light diverging from the light emitter 3.

[0029] In contrast, in the laser processing head 1A according to the first embodiment, the luminous flux conversion optical element 15 is arranged between the first lens group 11 and the second lens group 12. Therefore, compared with the case of the first comparative example, it is easy to ensure a large distance between the light emitter 3 and the luminous flux conversion optical element 15. The laser processing head 1A is configured such that the luminous flux conversion optical element 15 is arranged between the first lens group 11 and the second lens group 12, and each of the first lens group 11 and the third lens group 13 is moved, so that a degree of change in the ring diameter can be increased without increasing the size of the optical system behind the first lens group 11. Fig. 3, the distance between the light emitter 3 and the first lens group 11 in the first embodiment is equal to the distance between the light emitter 3 and the luminous flux conversion optical element 15 in the first comparative example, but the optical system behind the first lens group 11 is smaller in the case of the first embodiment than in the first comparative example.

[0030] Furthermore, in the first comparative example, instead of ensuring a large distance between the light emitter 3 and the luminous flux conversion optical element 15, the ring diameter can be changed by reducing an opening angle of the conical shape of the luminous flux conversion optical element 15. However, if the opening angle of the conical shape of the luminous flux conversion optical element 15 is reduced, highly accurate alignment of the luminous flux conversion optical element 15 is required. The laser processing head 1A according to the first embodiment can increase the ring diameter without reducing the opening angle of the conical shape of the luminous flux conversion optical element 15.

[0031] As a position of the luminous flux conversion optical element 15 becomes closer to the light emitter 3, the intensity of the laser light entering the luminous flux conversion optical element 15 increases. As the intensity of the laser light entering the luminous flux conversion optical element 15 increases, there is a possibility that the luminous flux conversion optical element 15 is damaged due to heat buildup. In the case of the first comparative example, since the luminous flux conversion optical element 15 is disposed immediately behind the light emitter 3, the position of the luminous flux conversion optical element 15 tends to be close to the light emitter 3. On the other hand, in the laser processing head 1A according to the first embodiment, the luminous flux conversion optical element 15 is disposed between the first lens group 11 and the second lens group 12.Therefore, compared to the case of the first comparative example, the luminous flux conversion optical element 15 can be spaced apart from the first light emitter 3. The laser processing head 1A can prevent an increase in the intensity of the laser light entering the luminous flux conversion optical element 15 and can reduce the probability of damage to the luminous flux conversion optical element 15.

[0032] Fig. Fig. 4 is a diagram illustrating a configuration according to a second comparative example of the first embodiment. The configuration according to the second comparative example differs from the configuration of the first embodiment in that the luminous flux conversion optical element 15 is arranged between the third lens group 13 and the fourth lens group 14. A left part of Fig. 4 shows a state in which the first lens group 11 is moved toward the light emitter 3 and the third lens group 13 is moved toward the luminous flux conversion optical element 15. A right part of Fig. 4 shows a state in which the first lens group 11 is moved toward the second lens group 12, and the third lens group 13 is moved toward the second lens group 12. A Fig. The double arrow shown in Figure 4 indicates that the configuration according to the second comparison example is between the state shown in the left part of Fig. 4 and the state shown in the right part of Fig. 4 is shown.

[0033] In the case of the second comparative example, a thickness of the ring in the annular beam profile changes mainly by moving the first lens group 11 and the third lens group 13. A ring width is in a beam profile 23 in the one shown in the left part of Fig. 4 shown state, and the ring width is in a beam profile 24 in the right part of Fig. 4. In the case of the second comparative example, a change in the thickness of the ring is large, whereas a change in the ring diameter is small.

[0034] The laser processing head 1A according to the first embodiment can greatly change the ring diameter without greatly increasing the thickness of the ring. The laser processing head 1A can increase the energy density in an outer peripheral portion compared to the case where the thickness of the ring increases significantly. As a result, the laser processing head 1A can achieve high-quality and efficient processing according to a material of the workpiece 5 or a thickness of the workpiece 5.

[0035] As described above, a form of change in the beam profile by moving the first lens group 11 and the third lens group 13 differs depending on the position where the luminous flux conversion optical element 15 is disposed. By disposing the luminous flux conversion optical element 15 along the optical axis between the first lens group 11 and the second lens group 12 in the laser processing head 1A, it is possible to achieve high-quality processing and high-efficiency processing on workpieces 5 of different materials or different thicknesses.

[0036] Further, the laser processing head 1A can change the distance from the light emitter 3 to the transfer position while maintaining a transfer magnification by moving the first lens group 11 and the third lens group 13. Fig. 5 is a diagram illustrating an example in which a distance from the light emitter 3 to the transfer position is changed by the laser processing head 1A according to the first embodiment.

[0037] A left part of Fig. 5 shows a state in which a transfer position 6 on the laser processing head 1A side is set with respect to a position on the workpiece 5. A right part of Fig. 5 shows a state in which the transfer position 6 is set on a side opposite to the laser processing head 1A with respect to a position of the workpiece 5. Fig. The double arrow shown in Figure 5 indicates that the laser processing head 1A is positioned between the laser beam shown in the left part of Fig. 5 and the state shown in the right part of Fig. 5. The laser processing head 1A can change the transfer position 6 in the optical axis direction by appropriately adjusting a position of the first lens group 11 and a position of the third lens group 13. As a result, the laser processing head 1A can achieve high-quality processing and high-efficiency processing on workpieces 5 of different materials or different thicknesses.

[0038] Since the number of luminous flux conversion optical elements 15 required for the laser processing head 1A is one, the laser processing head 1A can reduce the cost of the optical system compared to a case where two axicon lenses are required, as described in Patent Literature 1. In addition, when the two axicon lenses described in Patent Literature 1 are moved, there is a concern about damage to each axicon lens due to contact between the axicon lenses. The laser processing head 1A can eliminate such concerns.

[0039] Note that in the above description, the laser processing head 1A includes the moving device that moves the first lens group 11 and the moving device that moves the third lens group 13. The laser processing head 1A may also include a moving device that moves an optical component other than the first lens group 11 or the third lens group 13. For example, a moving device for moving the second lens group 12 or the fourth lens group 14 may be added to the laser processing head 1A. As a result, the laser processing head 1A can appropriately perform adjustment for improving processing quality or adjustment for improving productivity.

[0040] In the above description, the luminous flux conversion optical element 15 is an axicon lens, but the luminous flux conversion optical element 15 may be an optical element other than the axicon lens. The luminous flux conversion optical element 15 may be an optical element having a shape other than a conical shape, such as a polyhedral shape or an aspherical shape. The luminous flux conversion optical element 15 may be an array-type optical element in which many shapes, such as a conical shape, a polyhedral shape, and an aspherical shape, are arranged. The luminous flux conversion optical element 15 is not limited to a refractive optical element and may also be a diffractive optical element.

[0041] According to the first embodiment, the laser processing head 1A includes: the first lens group 11; the second lens group 12; the third lens group 13; the fourth lens group 14; and the luminous flux conversion optical element 15 arranged along the optical axis between the first lens group 11 and the second lens group 12. Furthermore, the laser processing head 1A includes the first moving device 17 that moves the first lens group 11 and the second moving device 18 that moves the third lens group 13. The laser processing head 1A can easily convert a beam profile of a laser beam by moving the first lens group 11 and the third lens group 13. The laser processing head 1A can improve processing quality and productivity by selecting the beam profile in accordance with a material of the workpiece 5 or a thickness of the workpiece 5.As described above, the laser processing head 1A has the effect of achieving high-quality processing through beam profile conversion. Furthermore, the laser processing head 1A can improve productivity. Second embodiment

[0042] Fig. 6 is a diagram illustrating an exemplary configuration of a laser processing head 1B according to a second embodiment. The laser processing head 1B includes a third moving device 19 in addition to configurations similar to the laser processing head 1A according to the first embodiment. In the second embodiment, components identical to those in the above-described first embodiment are denoted by identical reference numerals, and configurations different from those of the first embodiment will be described primarily.

[0043] The third moving device 19 moves the luminous flux conversion optical element 15 to a position along an optical axis between the first lens group 11 and the second lens group 12 and to a position outside the optical axis. Fig. In the example shown in Figure 6, the third moving device moves the optical flux conversion element 15 by rotating the optical flux conversion element 15 about an axis perpendicular to the optical axis. The optical flux conversion element 15 is attached to a rotatable mount connected to the third moving device 19. The optical flux conversion element 15 moves together with the mount through the rotation of the third moving device 19. An illustration of the mount has been omitted.

[0044] The controller 4 transmits a control signal to each of the first moving device 17, the second moving device 18, and the third moving device 19. The third moving device 19 moves the optical light flux conversion element 15 in response to the control signal. The controller 4 controls the first moving device 17, the second moving device 18, and the third moving device 19 by sending a control signal to each of the first moving device 17, the second moving device 18, and the third moving device 19.

[0045] In Fig. 6, a solid line indicates the luminous flux conversion optical element 15 when the luminous flux conversion optical element 15 is arranged at a position along the optical axis. In Fig. 6, a dashed line indicates the optical luminous flux conversion element 15 and a part of the third moving device 19 when the optical luminous flux conversion element 15 is outside the optical axis. Fig. 6, a dashed line indicates a trajectory along which the luminous flux conversion optical element 15 moves. The first moving device 17 moves the first lens group 11 when the third moving device 19 moves the luminous flux conversion optical element 15. By moving the first lens group 11 before the movement of the luminous flux conversion optical element 15, the laser processing head 1B can prevent the first lens group 11 from interfering with the movement of the luminous flux conversion optical element 15. Fig. 6, a dashed line indicates the first lens group 11 and a part of the first moving device 17 when the first lens group 11 was moved before the movement of the luminous flux conversion optical element 15.

[0046] Next, an operation of the laser processing head 1B when converting a beam profile of a laser beam emitted from the laser processing head 1B will be described.

[0047] Fig. 7 is a first diagram for explaining an operation of the laser processing head 1B according to the second embodiment. Fig. 7 illustrates a state in which the luminous flux conversion optical element 15 is arranged along the optical axis, and a state in which the luminous flux conversion optical element 15 is arranged at a position outside the optical axis. In Fig. 17 shows a main configuration of the laser processing head 1B, and illustration of other configurations of the laser processing head 1B is omitted.

[0048] Here, a reference is made to a section in the left part of Fig. 7 is referred to as a third state. Furthermore, a state shown in a right part of Fig. 7 is referred to as a fourth state. In the third state, the luminous flux conversion optical element 15 is arranged along the optical axis. A positional relationship between the first lens group 11, the third lens group 13, and the luminous flux conversion optical element 15 in the third state is the same as that shown in the left part of Fig. 2. A beam profile 15 in the third state is similar to that shown in Fig. 2. In the third state, the laser processing head 1B changes a ring diameter by appropriately moving the first lens group 11 and the third lens group 13, comparable to the case of the first embodiment.

[0049] From the third state, the first lens group 11 is moved toward the light emitter 3 by the first moving device 17, and then the third moving device 19 moves the luminous flux conversion optical element 15 away from the optical axis. That is, the third moving device 19 removes the luminous flux conversion optical element 15 from the optical axis. In the Fig. In the example shown in Figure 7, the optical flux conversion element 15 is moved out of the optical axis, and then the first moving device 17 returns the first lens group 11 to the original position. As a result, the laser processing head 1B transitions from the third state to the fourth state. As described above, the state of the laser processing head 1B is switched between the third state and the fourth state by moving the optical flux conversion element 15 by means of the third moving device 19. Further, when the optical flux conversion element 15 is to be moved by the third moving device 19, the laser processing head 1B moves the first lens group 11 using the first moving device 17. Fig. The double arrow shown in Fig. 7 indicates that the state of the laser processing head 1B can be switched between the third state and the fourth state.

[0050] In the fourth state, an image of the light emitter 3 is transferred through the optical transfer system 10. In a case where the transmission line 2 is a light guide, the transfer image of the light emitter 3 is circular. In this case, a circular beam profile 26 can be obtained in the fourth state. The laser processing head 1B can convert the beam profile by inserting the luminous flux conversion optical element 15 into the optical axis and extending the luminous flux conversion optical element 15 from the optical axis.

[0051] Further, in the fourth state, the laser processing head 1B can change a beam diameter by appropriately moving the first lens group 11 and the third lens group 13.

[0052] Fig. 8 is a second diagram for explaining an operation of the laser processing head 1B according to the second embodiment. Fig. 8 shows a state in which both the first lens group 11 and the third lens group 13 are moved along the optical axis in the fourth state. In Fig. 8, a main configuration of the laser processing head 1B is illustrated, and illustration of other configurations of the laser processing head 1B is omitted.

[0053] In a left part of Fig. 8, the first lens group 11 is moved towards the light emitter 3, and the third lens group 13 is moved towards the fourth lens group 14. This means that the image shown in the left part of Fig. The state shown in Fig. 8 is a state in which the first lens group 11 and the third lens group 13 have been moved in directions away from each other. On the other hand, in a right part of Fig. 8 shows a state in which the first lens group 11 is moved towards the second lens group 12, and the third lens group 13 is moved towards the second lens group 12. This means that the image in the right part of Fig. The state shown in Fig. 8 is a state in which the first lens group 11 and the third lens group 13 have been moved in directions approaching each other. Fig. The double arrow shown in Figure 8 indicates that the laser processing head 1B is positioned between the laser beam shown in the left part of Fig. 8 and the state shown in the right part of Fig. 8. The laser processing head 1B changes a transfer magnification of the transfer optical system 10 by moving the first lens group 11 and the third lens group 13.

[0054] In the right part of Fig. 8, a beam diameter in a beam profile 28 is smaller than a beam diameter in a beam profile 27 in the state shown in the left part of Fig. 8. By moving the first lens group 11 and the third lens group 13 in directions approaching each other, the beam diameter decreases. In addition, by moving the first lens group 11 and the third lens group 13 in directions away from each other, the beam diameter increases. In this way, the laser processing head 1B converts the beam diameter of the laser beam.

[0055] The laser processing head 1B switches the shape of the beam profile between a ring shape and a circular shape by moving the luminous flux conversion optical element 15. The laser processing head 1B changes the ring diameter of the annular beam profile by moving the first lens group 11 and the third lens group 13 to the third state in which the luminous flux conversion optical element 15 is arranged along the optical axis. The laser processing head 1B changes the beam diameter in the circular beam profile by moving the first lens group 11 and the third lens group 13 to the fourth state in which the luminous flux conversion optical element 15 is retracted outside the optical axis.

[0056] Through the movement of the first lens group 11, the movement of the third lens group 13, and the movement of the luminous flux conversion optical element 15, the laser processing head 1B can easily select a ring diameter or beam diameter and a beam profile suitable for a processing target. By appropriately selecting the ring diameter or beam diameter and the beam profile in accordance with a material of the workpiece 5 or a thickness of the workpiece 5, it is possible to improve the processing quality and improve productivity.

[0057] The laser processing head 1B creates a clearance for moving the luminous flux conversion optical element 15 by moving the first lens group 11 when the third moving device 19 moves the luminous flux conversion optical element 15. Therefore, the laser processing head 1B does not always need to ensure the clearance for moving the luminous flux conversion optical element 15 in the optical system, and the optical system can be downsized. The laser processing head 1B also uses the first moving device 17, which is used for converting the ring diameter, as a clearance-generating moving device. It is not necessary for the laser processing head 1B to provide a clearance-generating moving device separate from the first moving device 17, which is used for converting the ring diameter.When the luminous flux conversion optical element 15 is moved by rotating the luminous flux conversion optical element 15 about an axis perpendicular to the optical axis, the clearance through which the luminous flux conversion optical element 15 passes is required along the optical axis, so that the effect of the configuration in which the first lens group 11 is moved by the first moving device 17 is large.

[0058] With a simple configuration of rotating the luminous flux conversion optical element 15 around an axis perpendicular to the optical axis, the laser processing head 1B can move the luminous flux conversion optical element 15 to a position within the optical axis between the first lens group 11 and the second lens group 12 and a position outside the optical axis. Note that the third moving device 19 is not limited to the mechanism that rotates the luminous flux conversion optical element 15 around an axis perpendicular to the optical axis. The third moving device 19 may also be a mechanism that rotates the luminous flux conversion optical element 15 around an axis parallel to the optical axis. Alternatively, the third moving device 19 may be a mechanism that moves the luminous flux conversion optical element 15 along a plane perpendicular to the optical axis.The third moving device 19 only needs to be a mechanism that moves the luminous flux conversion optical element 15 to a position on the optical axis between the first lens group 11 and the second lens group 12 and to a position off the optical axis. When the luminous flux conversion element 15 is rotated about an axis perpendicular to the optical axis, the housing 16 can be downsized compared to a case where the luminous flux conversion element 15 is rotated about an axis parallel to the optical axis or a case where the luminous flux conversion element 15 is moved along a plane perpendicular to the optical axis.

[0059] The laser processing head 1B is configured to move the luminous flux conversion optical element 15 so that the presence or absence of the effect of the luminous flux conversion optical element 15 is switched using an optical system included in the laser processing head 1B. By switching the presence or absence of the effect of the luminous flux conversion optical element 15, the laser processing head 1B can switch between the annular beam profile and a beam profile that is a transfer image of the light emitter 3. Further, by moving the first lens group 11 and moving the third lens group 13, the laser processing head 1B can perform beam profile conversion of changing the ring diameter and beam profile conversion of changing the magnification of the transfer image.

[0060] According to the second embodiment, the laser processing head 1B moves the luminous flux conversion optical element 15 using the third moving device 19 to a position along the optical axis between the first lens group 11 and the second lens group 12 and a position off the optical axis. The laser processing head 1B can easily convert the beam profile of the laser beam by moving the luminous flux conversion optical element 15. Further, the laser processing head 1B can easily convert a beam profile of a laser beam by moving the first lens group 11 and moving the third lens group 13. The laser processing head 1B can improve processing quality and productivity by selecting the beam profile in accordance with a material of the workpiece 5 or a thickness of the workpiece 5.As described above, the laser processing head 1B has the effect of achieving high-quality processing through beam profile conversion. Furthermore, the laser processing head 1B can improve productivity. Third embodiment

[0061] In a third embodiment, a laser machine comprising the laser processing head 1A or the laser processing head 1B is described. Fig. 9 is a diagram illustrating an exemplary configuration of a laser machine 100 according to the third embodiment. Fig. The laser machine 100 shown in Figure 9 includes the laser processing head 1A according to the first embodiment. The laser machine 100 may include the laser processing head 1B according to the second embodiment instead of the laser processing head 1A. In the third embodiment, components identical to those in the first or second embodiment are denoted by identical reference numerals, and configurations different from those in the first or second embodiment will be described primarily.

[0062] The laser machine 100 includes: a laser oscillator 7 as a light source that outputs laser light; the laser processing head 1A; the transmission line 2 as a transmission path for the laser light from the laser oscillator 7 to the laser processing head 1A; a worktable 8 on which the workpiece 5 is placed; and the controller 4 that controls the laser machine 100. The laser machine 100 is configured to process the workpiece 5 by irradiating the workpiece 5 with a laser beam 9 emitted from the laser processing head 1A. The laser processing head 1A blows processing gas onto the workpiece 5. A member for blowing out the processing gas is not shown.

[0063] The laser machine 100 moves the laser beam 9 and the workpiece 5 relative to each other by moving the work table 8 with respect to the laser processing head 1A. The work table 8 is movable in a two-dimensional direction perpendicular to a central axis of the laser beam 9. Fig. 9, white double arrows indicate directions in which the worktable 8 can be moved. Note that the laser machine 100 can move the laser beam 9 and the workpiece 5 relatively without moving the worktable 8. The laser machine 100 can fix a position of the worktable 8 and control an incident position of the laser beam 9 on the workpiece 5.

[0064] The controller 4 transmits a control signal to each of the laser processing head 1A, the laser oscillator 7, and the worktable 8. The laser oscillator 7 outputs the laser light in response to the control signal. As described in the first embodiment, the laser processing head 1A moves the first lens group 11 and the third lens group 13 in response to the control signal. The worktable 8 is actuated in response to the control signal. In this way, the controller 4 controls each of the laser processing head 1A, the laser oscillator 7, and the worktable 8.

[0065] According to the third embodiment, the laser machine 100 includes the laser processing head 1A or the laser processing head 1B, so that the workpiece can be processed by appropriately selecting a beam profile in accordance with a material of the workpiece 5 or a thickness of the workpiece 5. The laser machine 100 can improve processing quality and productivity by selecting the beam profile. The laser machine 100 has an effect of achieving high-quality processing through beam profile conversion. In addition, the laser machine 100 can improve productivity. The laser machine 100 can improve processing quality and productivity, particularly for a medium-thickness plate or a plate thicker than a medium-thickness plate.

[0066] Next, a hardware configuration for implementing the controller 4 according to the first or second embodiment will be described. The controller 4 is implemented by a processing circuit. The processing circuit may be a circuit in which a processor executes software or may be a dedicated circuit.

[0067] In a case where the processing circuit is implemented by software, the processing circuit is, for example, a Fig. Control circuit shown in Figure 10. Fig. 10 is a diagram illustrating an exemplary configuration of a control circuit 30 according to the first or second embodiment. The control circuit 30 includes an input unit 31, a processor 32, a storage unit 33, and an output unit 34.

[0068] The input unit 31 is an interface circuit that receives data input from outside the control circuit 30 and forwards the data to the processor 32. The output unit 34 is an interface circuit that sends data from the processor 32 or the memory unit 33 to outside the control circuit 30. In a case where the processing circuit Fig. 10, the functions of the controller 4 are implemented by the processor 32, which reads and executes a program stored in the memory unit 33. The memory unit 33 is also used as temporary memory in each of the processes performed by the processor 32.

[0069] The processor 32 is a central processing unit (CPU), a processing device, an arithmetic device, a microprocessor, a microcomputer, a processor, or a digital signal processor (DSP). The storage unit 33 corresponds, for example, to a non-volatile or volatile semiconductor memory such as a random access memory (RAM), a read-only memory (ROM), a flash memory, an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM) (registered trademark), a magnetic disk, a floppy disk, an optical disk, a compact disk, a minidisk, a digital versatile disk (DVD), or the like.

[0070] Fig. 10 is an example of hardware in a case where the controller 4 is implemented by the general-purpose processor 32 and the storage unit 33, but the controller 4 may also be implemented by a dedicated hardware circuit. Fig. 11 is a diagram illustrating an exemplary configuration of a dedicated hardware circuit 35 according to the first or second embodiment.

[0071] The dedicated hardware circuit 35 includes the input unit 31, the output unit 34, and a processing circuit 36. The processing circuit 36 ​​is a single circuit, a composite circuit, a programmed processor, a parallel-programmed processor, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or a circuit obtained by combining them. Note that the controller 4 can be implemented by combining the control circuit 30 and the hardware circuit 35.

[0072] The configuration described in each of the above embodiments represents an example of the contents of the present disclosure. The configuration of each embodiment can be combined with other known technologies. The configurations of the individual expressions can be appropriately combined. Part of the configuration of each embodiment may be omitted or changed without departing from the spirit of the present disclosure. List of reference symbols 1A, 1B laser processing head; 2 transmission line; 3 light emitters; 4 Control; 5 workpiece; 6 transfer position; 7 laser oscillator; 8 work table; 9 laser beam; 10 optical transfer system; 11 first lens group; 12 second lens group; 13 third lens group; 14 fourth lens group; 15 optical luminous flux conversion element; 16 housings; 17 first movement device; 18 second movement device; 19 third movement device; 21, 22, 23, 24, 25, 26, 27, 28 beam profile; 30 control circuit; 31 input unit; 32 processor; 33 storage unit; 34 output unit; 35 hardware circuit; 36 processing circuit; 100 laser machines. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] JP 2019 - 42 793

[0004]

Claims

[1] Laser processing head (1A; 1B), comprising: a first lens group (11) into which a laser light emanating from a light emitter (3) enters and which is designed to focus laser light; a second lens group (12) to which the laser light which has passed through the first lens group (11) propagates; a third lens group (13) for forming, together with the second lens group (12), a lens group adapted to form an image of the light emitter (3) at a transfer position (6), wherein the laser light which has passed through the second lens group (12) propagates to the lens group; a fourth lens group (14) into which the laser light which has passed through the third lens group (13) enters and which is designed to focus the laser light; an optical luminous flux conversion element (15) which is arranged along an optical axis between the first lens group (11) and the second lens group (12) and is designed to convert a beam profile of the laser light; a first moving device (17) adapted to move the first lens group (11) in a direction along the optical axis; and a second moving device (18) adapted to move the third lens group (13) in a direction along the optical axis. [2] Laser processing head (1A; 1B) according to claim 1, wherein the second lens group (12) is a lens group having a positive refractive power, and the third lens group (13) is a lens group having a negative refractive power. [3] Laser processing head (1A; 1B) according to claim 1 or 2, comprising: a third moving device (19) configured to move the luminous flux conversion optical element (15) into a position along an optical axis between the first lens group (11) and the second lens group (12) and a position outside the optical axis. [4] Laser processing head (1A; 1B) according to claim 3, wherein the first moving device (17) is configured to move the first lens group (11) when the third moving device (19) moves the luminous flux conversion optical element (15). [5] Laser processing head (1A; 1B) according to one of claims 1 to 3, wherein the optical luminous flux conversion element (15) is an axicon. [6] Laser machine (100), comprising: a light source (7) configured to emit laser light; and the laser processing head (1A; 1B) according to one of claims 1 to 5.

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