Processing head for a laser processing machine, as well as laser processing machine and method for changing a protective glass in the processing head

Abstract

Processing head (3) for a laser processing machine (10) for processing a workpiece (6) by means of a laser beam (5) which is focused by a focusing optic (17) arranged in a first housing part (12) of the processing head (3) and exits the processing head (3) through a protective glass (29) arranged in the direction of beam propagation downstream of the focusing optic (17), and the protective glass (29) is arranged in a second housing part (14) of the processing head (3), which is detachably attached to the first housing part (12) and which remains connected to the first housing part (12) by means of a coupling element (31) after being detached from the first housing part (12) and which is at least displaceable or pivotable relative to the first housing part (12), characterized in that the protective glass (29) is received in a socket (51),which is arranged in the second housing part (14) and comprises a rim (56) projecting towards an end face (54) in the second housing part (14), which has a break (57) and a clearance (58) is provided in the end face (54) of the second housing part (14), which adjoins the break (57).

Description

[0001] The invention relates to a processing head of a laser processing machine for processing a workpiece by means of a laser beam as well as to a laser processing machine and a method for changing a protective glass in the processing head.

[0002] The processing of workpieces, especially plate-shaped workpieces, using a laser beam is well known. The laser beam is guided over a processing head, focused by focusing optics, and directed onto the workpiece. These optical components are protected from contamination by splashes or smoke by a protective glass located in the workpiece-side end of the processing head. Depending on the parameters of the processing process, the protective glass becomes contaminated more or less quickly and must be replaced after a certain period of time.

[0003] From the company brochure of SCANLAB AG entitled: intelliWELD 30 FC Installation and Commissioning, Puchheim, 2011, a processing head for a laser processing machine is known. The processing head comprises a focusing optics in a first housing section of the processing head and a protective glass in a second housing section, which is arranged downstream of the focusing optics in the direction of beam propagation. To replace the protective glass, a screw connection between the second housing section and the first housing section is loosened. The second housing section is then carefully pulled down until it stops and then pivoted. The old or dirty protective glass can then be removed and a new protective glass inserted into the socket on the second housing section.

[0004] EP 2 108 475 A1 discloses a device for automatically changing cutting nozzles on the cutting heads of a laser cutting system. Replaceable cutting nozzles are provided on the cutting head. A cutting nozzle to be replaced is placed in a magazine. A new cutting nozzle is then provided by the nozzle change magazine, which is then picked up again by the cutting head.

[0005] Furthermore, CN 1 01 402 156 A discloses arranging multiple protective glass panels in a rotating disk on the processing head. If a protective glass panel becomes dirty, the disk continues to rotate to insert a new protective glass panel into the processing head. The used protective glass panel is removed from the processing head and can be cleaned.

[0006] DE 10 2004 002 839 A1 discloses a processing head in which a large rotating disk serves as a protective glass. Rotating the disk brings new areas or segments of the protective glass into the path of the laser beam. The disk is housed in a separate, large housing. When changing the disk, the entire housing, including the disk contained within, must be replaced.

[0007] KR 100 634 623 B1 discloses a changing device for protective lenses. A housing for stored new protective lenses is provided next to the processing head. The protective lenses are pushed by the changing device from the storage container into the laser beam path in the processing head. After the protective lens becomes dirty, the new protective lens pushes the protective lens located in the processing head into a second container for dirty protective lenses next to the processing head, where the dirty protective lenses are collected.

[0008] From JP S60 - 27 487 A a machining head is known in which the focusing optics are arranged in a first housing part and the protective glass is arranged in a second housing part of the machining head, which is detachably fastened to the second housing part, wherein the second housing part must be completely removed and disassembled from the first housing part in order to change the protective glass.

[0009] The invention is based on the object of proposing a processing head in which a protective glass can be replaced quickly and easily. Furthermore, the invention is based on the object of proposing a laser processing machine and a method in which a simple and rapid replacement of the protective glass in the processing head is possible.

[0010] This object is achieved on the one hand by a processing head which has a first and a second housing part, with a protective glass arranged in the second housing part. This second housing part is detachably attached to the first housing part and, after being detached from the first housing part, remains connected to the first housing part by a coupling element, but is at least displaceable or pivotable relative to the first housing part. This means that the second housing part can be quickly and easily moved into a changing position for removing and inserting the protective glass. The second housing half can be moved into the changing position using one hand. This means that the protective glass can be changed quickly and easily using the other clean hand. Likewise, the second housing part can be moved into a closed position with a one-hand movement relative to the first housing part.Likewise, an automated protective glass change can be easily controlled and carried out with such a processing head.

[0011] To securely hold the protective glass, a mount is provided in the first housing part. This mount has a border around the protective glass that protrudes from a front surface of the second housing part and has at least one interruption. This interruption facilitates access to the protective glass.

[0012] Adjacent to the frame's perimeter, a cutout is provided in the front face of the second housing part, which corresponds to the interruption in the perimeter. This cutout allows for even easier gripping of the side surface of the protective glass.

[0013] The detachment of the second housing part from the first housing part by means of a sliding movement can be carried out, for example, by a linear movement which is in particular in the beam axis or perpendicular to the beam axis.

[0014] According to a preferred embodiment of the invention, the coupling element is formed by a rotational axis, and the second housing part can be pivoted relative to the first housing part by rotation about the rotational axis. This enables good accessibility for removing the dirty protective glass and subsequently inserting a new protective glass by simply a pivoting movement. The rotational axis can be arranged either perpendicularly or parallel to the parting plane between the first and second housing parts. If the rotational axis lies in the parting plane on an outer edge of the processing head, the processing head can be opened by folding it open, i.e. by tilting the second housing part about the pivot axis.

[0015] According to a further preferred embodiment of the invention, the coupling element can be formed by a lifting and rotating axis. This allows, for example, the second housing part to be initially lifted relative to the first housing part or vice versa, or to be separated by a linear movement. Subsequently, the second housing part can be pivoted relative to the first housing part or vice versa by rotating about the rotating axis. This allows good access to the protective glass from above, allowing a visual inspection of the protective glass frame before inserting the new protective glass.

[0016] For a quick change of a protective gas, it is preferably provided that this is arranged in a parting plane between the first and second housing part.

[0017] Preferably, the protective glass can form part of an end face of the second housing part facing the first housing part. This allows the protective glass to be arranged at least partially raised relative to the end face of the second housing part, facilitating removal. The protective glass is thus enclosed and positioned between the first and second housing parts, which also enables a sealing arrangement in the processing head in the direction of the focusing optics.

[0018] Furthermore, the mount in the second housing part is designed such that a protective glass protrudes beyond the frame's perimeter. In this way, the protective glass forms a contact surface for contact with the first housing part. This allows the protective glass to be arranged in the mount of the first housing part, sealing it against the interior of the first housing chamber or the focusing optics, by means of a sealing ring.

[0019] The coupling element, designed as a lifting and rotation axis, can be arranged with one end fixed to the second or first housing part and with an opposite end positioned in a bore in the first or second housing part so that it can be moved and pivoted. This allows the second housing part to initially perform a lifting movement relative to the first housing part along the longitudinal axis of the lifting and rotation axis, while the position of the protective glass in an XY plane remains unchanged. Subsequently, a rotation can occur around this vertically extending longitudinal axis of the lifting and rotation axis, thus providing particularly good accessibility to the protective glass.

[0020] The coupling element, designed as a lifting and rotation axis, includes a circumferential shoulder, preferably in the central region, which limits the lifting movement between the first and second housing parts. This enables a space-saving and structurally simple design.

[0021] The end of the lifting axis inserted into the bore of the first or second housing part can have notches on its outer circumference, into which a locking element arranged in the housing part associated with this end of the lifting axis engages and fixes a set rotational position between the first and second housing parts. This allows a set pivoting movement or pivoting of the second housing part relative to the first housing part to be fixed, thus facilitating the removal and subsequent insertion of the protective glass.

[0022] To securely join the second housing part to the first housing part, a centering pin is preferably provided on the first or second housing part facing the opposite housing part, which engages into a centering hole in the opposite housing part. This ensures that the protective glass is inserted into the corresponding first half of the mount in the first housing part and, for example, that contact pins of the processing head electronics, which are inserted on the front side of the first housing part and on the front surface of the second housing part, are securely connected and contacted with each other.

[0023] Furthermore, a quick-release fastener can be provided between the first and second housing parts, by which the first and second housing parts are releasably fastened to one another. Such a quick-release fastener enables both tool-free detachment and connection of the housing parts from one another and to one another.

[0024] According to one embodiment of a quick-release fastener, a spring-loaded slide element can be provided, which engages with fixing elements and can be released by a sliding movement relative to the fixing element. Advantageously, the fixing element can have a clamping head that engages in a keyhole opening of a slide element, thus fastening or releasably connecting the slide element to the fixing element depending on the sliding movement. The slide element can be moved into a release position against a restoring force of a restoring element, in particular a spring force of a spring element, and can return independently to a locking position due to the restoring force or spring force.This makes it possible to create an embodiment that requires active actuation of the quick-release fastener to detach the second housing part from the first housing part, whereas connecting the two housing parts is sufficient simply by correctly positioning and moving the first and second housing parts toward each other. Alternatively, the quick-release fastener can also be actuated to transfer the second housing part to the first housing part in a closed position of the machining head, and after its release, the two housing parts can be locked together.

[0025] The first and second housing parts can alternatively be detachably attached to each other by a screw connection. Advantageously, two diagonally opposite screws are provided for detachable fastening. This allows for quick and easy replacement.

[0026] The screws of the screw connection are secured against loosening from the first or second housing part, i.e., they are captively attached to the housing part. This means that only one loosening of the screw connection is required, and then, for example, the second housing part automatically lowers relative to the first housing part due to gravity, so that a subsequent pivoting movement already assumes the changing position of the second housing part relative to the first housing part. The second housing part is then fastened to the first housing part in the reverse order of the movements and can again be performed using one-hand operation, allowing the screws to be easily tightened with the other hand.

[0027] The object underlying the invention is also achieved by a processing machine, in particular a laser processing machine, with a processing head as described above, in which the first and second housing parts can be detached and connected to one another by a quick-release fastener. The processing machine comprises a changing station with a receiving device in which the processing head can be positioned and which further comprises a release device that enables the quick-release fastener of the processing head to be released, by means of which the first and second housing parts are detachably connected to one another. This changing station can at least partially automate the changing of the protective glass. This enables, on the one hand, a secure reception of the processing head in the changing station and, on the other hand, a simultaneous detachment of the housing parts from one another.Alternatively, the quick release can also be activated separately after the machining head has been inserted into the changing station.

[0028] The receiving device of the exchange station is designed as a clamping device, in which the second housing part is preferably positioned by clamping. A U-shaped clamping receptacle or a receiving area is preferably provided, allowing easy insertion of the machining head, in particular the second housing part, on which a receptacle adapted to the clamping device is provided.

[0029] The release mechanism of the change station can be implemented as a separately driven control cam. The release mechanism can also be implemented as a stop surface, so that, for example, when positioning the machining head in the holding device, the quick-release fastener is simultaneously activated—in particular, released.

[0030] The replacement station preferably has at least one rinsing device for rinsing the second housing part. This allows for very clean ambient conditions and prevents contamination inside the second housing part. Rinsing can also take place while inserting the new protective glass, ensuring clean working conditions.

[0031] The changing station of the laser processing machine advantageously includes a protective glass magazine. This allows several protective glasses to be kept ready for replacement in the changing station simultaneously. The protective glass can be replaced either manually or using a mechanical gripper device. Preferably, the protective glass magazine can also be positioned on the second housing part and be immediately usable.

[0032] The object underlying the invention is further achieved by a method for changing a protective glass in a previously described processing head of a previously described laser processing machine, in which at least one linear axis or a handling device of the laser processing machine, which carries the processing head, positions the processing head in a receiving device of the changing station. During this positioning of the processing head in the receiving device or subsequently, a quick-release fastener on the processing head can be moved into a release position by a release device of the changing station, whereby the second housing part and the first housing part can be detached from one another, but remain connected to one another by a coupling element. By at least one linear axis or a handling device, one of the two housing parts can be moved to a changing position relative to the other.This can reduce machine downtime.

[0033] Furthermore, a gaseous medium is preferably supplied to flush the second housing part, at least after the first and second housing parts have been separated from a closed position. This allows contaminants to be removed and clean ambient conditions to be achieved. Additionally, a protective glass magazine can also be flushed with a gaseous medium.

[0034] A further advantageous embodiment of the method provides for a protective glass magazine to be positioned relative to the mount of the second housing part, and for a protective glass to be inserted from the magazine into the mount of the second housing part. This allows for a fully automatic change of the protective glass. Subsequently, the housing parts are moved into a closed position by the at least one linear axis or handling device, so that the machining head can be removed from the change station for the subsequent work steps.

[0035] The invention and further advantageous embodiments and developments thereof are described and explained in more detail below with reference to the examples shown in the drawings. They show: Fig. 1 a perspective view of a laser processing machine, Fig. 2 a schematic side view of a processing head of the laser processing machine according to Fig. 1, Fig. 3 a schematic view from below of the machining head according to Fig. 2, Fig. 4 a perspective view from above of the machining head in a changing position of a second housing part, Fig. 5 a perspective view from below of the machining head according to Fig. 4, Fig. 6 a schematic side view in partial section of the machining head according to Fig. 4, Fig. 7 a perspective view of a coupling element, Fig. 8 a schematic side view of a processing head in a changing station of the laser processing machine, Fig. 9a and Fig. 9b perspective views of details of a quick release of the machining head and Fig. 10 a schematic side view of a machining head in a change position with a protective glass magazine.

[0036] In Fig. 1 shows a perspective view of a processing machine 10, which shows the structure of a laser cutting machine as an exemplary embodiment of a laser processing machine. Further exemplary embodiments include, for example, a laser welding machine or a combined punching / laser cutting machine. This processing machine 10 has a CO2 laser or solid-state laser as the laser beam generator 2, a laser processing head or processing head 3, and a workpiece support 4. A workpiece 6 is arranged on the workpiece support 4. A laser beam 5 is generated by the laser 2. The laser beam 5 is guided from the CO2 laser to the processing head 3 with the aid of deflecting mirrors (not shown) or from the solid-state laser with the aid of a fiber optic cable (not shown). The laser beam 5 is directed onto the workpiece 6 by means of focusing optics arranged in the processing head 3.The processing machine 10 is also supplied with cutting gases 7, for example, oxygen and nitrogen. Compressed air or application-specific gases can be provided alternatively or additionally. The use of the individual gases depends on the material of the workpiece 6 to be processed and the quality requirements for the cut edges. Furthermore, an extraction device 8 is provided, which is connected to an extraction channel 16 located beneath the workpiece support 4.

[0037] When cutting the workpiece 6 using oxygen as the cutting gas, the material of the workpiece 6 is melted and largely oxidized. When using inert gases such as nitrogen or argon, the material is merely melted. The resulting melt particles, possibly together with the iron oxides, are then blown out and extracted together with the cutting gas via the extraction channel 16 by the extraction device 8.

[0038] Fig. 2 shows a schematically enlarged side view of the processing head 3 according to Fig. 1. The processing head 3 comprises a first housing part 12 and a second housing part 14, which are detachably connected to one another at a common parting plane 15. The first housing part 12 has a focusing optics 17 (illustrated only symbolically), e.g., one or more focusing lenses, inside it, to which the laser beam 3 is fed via a feed 18. The laser beam is focused in this focusing optics 17 and exits a nozzle 21 arranged on the second housing part 14. Furthermore, the cutting gas 7 is supplied to the first housing part 12 via a connection 22.

[0039] According to a first embodiment, the second housing part 14 is detachably fastened to the first housing part 12 by a screw connection 24. The screw connection 24 comprises, for example, two screws 25 which engage the housing part 14 diagonally offset from one another, as can be seen from the view from below of the machining head 3 according to Fig. 3. The screw connection 24 comprises two screws 25 that penetrate the second housing part and engage a mounting plate 26 of the first housing part 12. Preferably, after the screws 25 are removed from the mounting plate 26, they remain in their bores in the second housing part 14 and do not fall out. The screws can be captively secured by retaining rings or the like.

[0040] In Fig. 4 shows a perspective view from above of the processing head 3 in a changing position 28 for a protective glass 29. Fig. 5 shows the Fig. 4 shows the machining head 3 shown in the change position 28 in a perspective view from below.

[0041] The first and second housing parts 12, 14 are connected to one another by a coupling element 31, which is designed as a lifting and rotating axis. After loosening the screw connection 24, the second housing part 14 can be lowered along a Z-axis relative to the first housing part 12 and then moved into the exchange position 28 by rotation about the Z-axis—i.e., about the longitudinal axis of the coupling element 31. In this exchange position 28, the protective glass 29 can be easily removed and a new protective glass 29 can then be easily inserted into the second housing part 14. The lifting and rotating movement of the second housing part 14 relative to the first housing part 12 can be performed using one hand.

[0042] The structural design and arrangement of the coupling element 31 to the second housing part 14 are described with reference to Fig. 6 and Fig. 7 discussed.

[0043] The coupling element 31 has a first end 32, which is formed, for example, by a screw thread 33, to which a cylindrical section acts as a locating pin 34. This first end 32 is screwed into a corresponding bore 35 in the second housing part 14. For this purpose, flattened portions 36 are provided so that the coupling element 31 can be secured with a wrench. The locating pin 34 ensures that the second housing part 14 is positioned correctly—i.e., perpendicular—to the longitudinal axis of the coupling element 31. The end 32 is connected to the second housing part 14 in a rotationally fixed manner. The opposite end 38 of the coupling element 31 is inserted into a bore 39 in the first housing part 12 so that it can be immersed. A spring element 41 is inserted into the bore 39 and presses the free end 38 of the coupling element 31 out of the bore 39.This movement is limited by a shoulder 43 in the central region of the coupling element 31, which rests against a through-hole 44 of the mounting plate 26. This design limits the lifting movement for raising or lowering the second housing part 14 relative to the first housing part 12.

[0044] At the end 38 of the coupling element 31, notches 46 are provided, distributed radially around the circumference, into which a locking element 47, designed, for example, as a ball thrust piece, engages. This locking element 47 is positioned in the first housing part 12 radially aligned with the longitudinal axis of the coupling element 31. The notches 46 are preferably designed as circular arc-segment-shaped depressions extending in the axial direction, thus enabling simplified release between the locking element 37 and the coupling element 31 with a lifting movement.

[0045] The protective glass 29 is positioned in a mount 51, which is integrated into an end face 54 of the second housing part 14 or is recessed relative thereto. The mount 51 has a border 56 on the second housing part 14, which border comprises at least one interruption 57. In this interruption 57 and adjacent thereto, a recess 58 is provided in the end face 54 of the second housing part 14. This facilitates removal of the protective glass 29, since a finger of the operator partially dips into the recess 58 and, due to the interruption 57, completely engages a circumferential surface of the protective glass 29. This is preferably in Fig. 4, a second interruption 57 is provided opposite the interruption 57 shown, as can be seen from Fig. 6. The border 56 is provided in height relative to the frame 51 such that the protective glass 29 protrudes slightly relative to the border 56. This allows it to be in a closed position 61 of the processing head 3 according to Fig. 2 be arranged sealingly against a sealing surface of the first housing part 12.

[0046] A centering pin 63 protrudes from the end face 54 and engages a centering bore 64 on the first housing part 12. This can also be reversed. Contact elements 66 are also provided on the end face 54, which are conductively connected to one another at opposite terminals 67 on the mounting plate 26 of the first housing part 12 in the closed position 61.

[0047] In Fig. 8 shows a schematic side view of a processing head 3, whereby initially only the processing head 3 with its quick-release fastener 71 is discussed.

[0048] The quick release 71 can be used instead of the Fig. 2 to 6 and allows for simplified handling. According to one embodiment, the quick-release fastener can have an L-shaped slide element 72, which, for example, Fig. 9a. This slide element 72 has an actuating surface 73, by means of which the slide element 72 moves against a restoring force of a restoring element 74 from a locking position into a release position 76, as shown schematically in Fig. 9b. The slide element 72 has at least one keyhole opening 77, into which a fixing element 78 engages with a head 79 that is larger than a shaft 80. In the release position 76, the head 79 can be guided through the enlarged opening of the keyhole opening 77, so that the slide element 72 is free from the fixing element 78. The fixing element 78 is fastened, for example, to the second housing part 14 with the shaft 80. The slide element 72 is slidably arranged on the first housing part 12, in particular on the fastening plate 26.

[0049] In a locking position, the shaft 80 is positioned in the tapered region 81 of the keyhole opening 77, so that the head 79 rests on the slide element 72 and is secured against loosening. The keyhole openings 77 of the quick-release fastener 71 are preferably provided at the same positions as the screws 25, so that fixing elements 78 can be used instead of the screws 25, and a quick-release fastener 71 can also be provided on the processing head 3 in a simple manner.

[0050] This quick release 71 can enable both easy manual handling and automatic replacement of the protective glass 29.

[0051] For the partially or fully automated replacement of the protective glass 29, the processing head 3 is mounted with a linear axis in the laser processing machine in a changing station 85 according to Fig. 8. The exchange station 85 comprises a receiving device 86, which is designed, for example, as a clamping device and has a U-shaped recess or a U-shaped clamping area that engages a receiving section 87 on the second housing part 14. Furthermore, the exchange station 85 has a triggering device 88, which, according to a simple embodiment, is designed as a stop surface. The exchange station 85 can furthermore have, associated with the stop surface 88, a run-up slope 94 for actuating a slide element 72 of a quick-release fastener 71.

[0052] Additionally, the exchange station 85 can comprise a flushing device 89, which is provided at a lower section of the exchange station 85, which is opposite a nozzle opening 90 of the nozzle 21. The nozzle 21 sits on a connection 91. Opposite this is a supply line 92 for supplying a gaseous medium, in particular air, into the second housing part 14. With the aid of the gaseous medium, the protective glass 29 can be blown out of the frame 51. This can take place, for example, in a position in which the protective glass 29 is thrown to the side in a defined manner over a baffle plate.

[0053] After the machining head 3 is inserted into the changing station 85, as Fig. 8 shows, the first housing part 12 can be lifted and pivoted relative to the second housing part 14 by means of the movement axes of the processing machine, so that a change position 28 between the first and second housing part 12, 14 is assumed, as shown for example in the Fig. 4 to 6. The protective glass 29 can then be removed, for example, manually or by means of a gripper device from the socket 51 of the second housing part or can be ejected by blowing in compressed air. After the new protective glass 29 has been inserted into the socket 51 of the second housing part 14, the first housing part 12 is pivoted back towards the second housing part 14 and lowered, with the centering bolts 63 and centering bore 64 ensuring exact alignment of the housing parts 12, 14 to one another. This ensures that the protective glass 29 is positioned correctly between the two housing parts 12, 14. The machining head 3 is then removed from the holding device 87 in the opposite direction to the X direction, with the quick-release fastener 71 simultaneously automatically moving into a locking position and the first and second housing parts 12, 14 being fixed to one another.

[0054] In Fig.10 further shows a schematic side view of the processing head 3, in which the first and second housing parts 12, 14 are arranged in a changing position 28 relative to one another. According to a first embodiment, the protective glass magazine 96 can be fastened on or next to the changing station 85. Furthermore, the protective glass magazine 96 can be fastened to the first housing part 12. When the first housing part 12 is rotated relative to the second housing part 14, the protective glass magazine 96 can be moved into a position such that the new protective glass 29 can be easily inserted from the protective glass magazine 96 via gravity directly into the socket 51 in the second housing part 14. Preferably, the second housing part and / or the protective glass magazine can be rinsed with a gaseous medium before and / or during the insertion of the new protective glass 29.

Claims

[1] Processing head (3) for a laser processing machine (10) for processing a workpiece (6) by means of a laser beam (5), which is focused by a focusing optics (17) arranged in a first housing part (12) of the processing head (3) and exits the processing head (3) through a protective glass (29) arranged downstream of the focusing optics (17) in the beam propagation direction, and the protective glass (29) is arranged in a second housing part (14) of the processing head (3), which is detachably fastened to the first housing part (12) and which remains connected to the first housing part (12) by a coupling element (31) after being released from the first housing part (12) and which is at least displaceable or pivotable relative to the first housing part (12), characterized bythat the protective glass (29) is accommodated in a frame (51) which is arranged in the second housing part (14) and comprises a border (56) which projects relative to an end face (54) in the second housing part (14) and which has an interruption (57), and that a clearance (58) is provided in the end face (54) of the second housing part (14), which border is adjacent to the interruption (57). [2] Machining head according to claim 1, characterized by that the coupling element (31) is formed by a rotation axis and the second housing part (14) can be pivoted relative to the first housing part (12) by rotation about the rotation axis. [3] Machining head according to claim 1, characterized bythat the coupling element (31) is formed by a lifting axis of rotation and the second housing part (14) can be lifted relative to the first housing part (12) or vice versa and the second housing part (12) can be pivoted relative to the first housing part (12) or vice versa by rotation about the axis of rotation of the coupling element (31). [4] Machining head according to claim 1, characterized by that the protective glass (29) is arranged in a parting plane (15) between the first and second housing parts (12, 14). [5] Machining head according to claim 1, characterized by that the protective glass (29) forms part of an end face (54) of the second housing part (14) facing the first housing part (12). [6] Machining head according to claim 1, characterized by that the protective glass (29) arranged in the frame (51) protrudes from the border (56). [7] Machining head according to claim 3, characterized bythat the coupling element (31) designed as a lifting axis of rotation is arranged with one end (32) in a stationary manner in the second or first housing part (14, 12) and is positioned with the opposite end (38) in the first or second housing part (12, 14) in a bore (39) so as to be displaceable and pivotable. [8] Machining head according to claim 7, characterized by that the lifting axis of rotation has a circumferential shoulder (43) which is formed to limit the lifting movement between the first and second housing part (12, 14). [9] Machining head according to claim 7 or 8, characterized by that at the end (38) of the lifting rotary axis which extends into the bore (39), notches (46) are provided on the outer circumference, into which notches a locking element (67) engages and fixes a set rotational position between the first and second housing part (12, 14). [10] Machining head according to one of the preceding claims, characterized bythat a centering pin (63) is provided on the first or second housing part (12, 14) pointing towards the opposite housing part (14, 12), which engages in a centering bore (64) in the opposite housing part (12, 14). [11] Machining head according to one of the preceding claims, characterized by that the first and second housing parts (12, 14) can be detached and connected to one another by a quick-release fastener (71). [12] Machining head according to claim 11, characterized by that a spring-loaded slide element (72) is provided, which is provided on one of the two housing parts (12, 14) and engages at least one fixing element (78) which is provided on the other of the two housing parts (12, 14) and can be released and locked by a sliding movement relative to the at least one fixing element (78). [13] Machining head according to claim 12, characterized bythat the slide element (72) has at least one keyhole opening (77) in which a head (79) of a fixing element (78) engages. [14] Machining head according to claim 13, characterized by that the slide element (72) can be transferred into a release position (76) against a restoring force of a restoring element (74) and can be reset into a locking position by the restoring force of the restoring element (74). [15] Machining head according to claim 1, characterized by that the first and second housing parts (12, 14) are releasably fastened to one another by a screw connection (24). [16] Machining head according to claim 15, characterized by that screws (25) of the screw connection are secured against loosening from the second housing part (14). [17] Processing machine for processing a workpiece (6) by means of a laser beam (5) which is directed onto the workpiece (6) with a processing head (3), wherein the processing head (3) is designed according to one of claims 11 to 14, characterized by that a changing station (85) is provided which comprises a receiving device (86) in which the processing head (3) can be positioned and which has a triggering device (88) for releasing the quick-release fastener (71) of the processing head (3), by means of which the first and the second housing part (12, 14) are detachably fastened and connected to one another. [18] Processing machine according to claim 17, characterized by that the receiving device (87) is designed as a clamping device in which the second housing part (14) is preferably positioned, wherein the receiving device (87) has a U-shaped receiving area which engages in a receiving section (87) of the second housing part (14). [19] Processing machine according to claim 17, characterized by that the triggering device (88) is designed as a control cam or a stop surface. [20] Processing machine according to claim 17, characterized by that the exchange station (85) comprises at least one flushing device (89) for introducing a gaseous medium into the second housing part (14). [21] Processing machine according to claim 17, characterized by that the changing station (85) comprises a protective glass magazine (96). [22] Method for changing a protective glass (29) in a processing head (3) according to one of claims 11 to 14 of a processing machine according to one of claims 17 to 21, characterized bythat the machining head (3) is positioned in a receiving device (87) of the changing station (85) by means of at least one linear axis or a handling device which carries the machining head (3), that during the positioning of the machining head (3) in the receiving device (86) or subsequently a quick-release fastener (71) on the machining head (3) is moved into a release position (76) by a release device (88) of the changing station (85), that at least one of the two housing parts (12, 14) is moved to the other housing part (14, 12) by means of the at least one linear axis or handling device into a changing position (28), wherein the first and second housing parts (12, 14) remain connected by a coupling element (31). [23] Method according to claim 22, characterized bythat at least after the first and second housing parts (12, 14) have been separated from a closed position (61), a gaseous medium is supplied to remove the protective glass (29) from the second housing part (14). [24] Method according to claim 22, characterized by that the protective glass (29) is removed from the socket (51) of the second housing part (14) by blowing out with a gaseous medium, by hand or a gripper device. [25] Method according to claim 22, characterized by that a protective glass magazine (96) is positioned relative to the socket (51) and a new protective glass (29) is inserted from the protective glass magazine (96) into the socket (51) of the second housing part (14).

Images