Device and method for laser beam welding

Abstract

The invention relates to a device (1) for laser beam welding, comprising a protective device (3) with a feed nozzle (4) for supplying a gaseous medium and an extraction unit (5) for extracting the gaseous medium. According to the invention, the feed nozzle (4) and the extraction unit (5) are arranged and spaced apart from each other in such a way that the gaseous medium supplied via the feed nozzle (4) and extracted by the extraction unit (5) forms a protective curtain (SV) between the feed nozzle (4) and the extraction unit (5) laterally next to a generated laser beam (LS). Furthermore, the invention relates to a method for operating the device (1).

Description

[0001] The invention relates to a device for laser beam welding according to the features of the preamble of claim 1 and a method for operating the device.

[0002] A laser welding device is known from the prior art, as described in DE 35 13 501 A1. The laser welding device comprises a nozzle for generating a transverse gas flow between the optics and the beam focus to deflect particles moving toward the optics. The receiving opening of a gas exhaust line is arranged opposite the nozzle. The nozzle is arranged within an injector casing. The injector casing and the gas exhaust line form a continuous flow channel with a transverse opening for the laser beam.

[0003] The invention is based on the object of providing a device for laser beam welding which is improved compared to the prior art and an improved method for operating the device.

[0004] The object is achieved according to the invention by a device for laser beam welding having the features of claim 1 and a method for operating the device having the features of claim 10.

[0005] Advantageous embodiments of the invention are the subject of the subclaims.

[0006] A device for laser beam welding has a protective device with a feed nozzle for supplying a gaseous medium and an extraction unit for extracting the gaseous medium.

[0007] According to the invention, the feed nozzle and the suction unit are arranged and spaced apart from one another in such a way that the gaseous medium fed via the feed nozzle and sucked away by the suction unit forms a protective curtain between the feed nozzle and the suction unit laterally next to a generated laser beam.

[0008] The feed nozzle and the extraction unit, and thus also the protective curtain created between them, are arranged in particular laterally offset relative to a component connection to be created by means of the laser beam, i.e., in particular laterally offset relative to a joining zone of at least one component to be welded or of several components to be welded together. Laterally offset means, in particular, at least substantially, offset in the radial direction of the joining zone and / or the laser beam and / or a laser welding optics of the device.

[0009] In a method according to the invention for operating the device, the protective curtain is formed between the feed nozzle and the extraction unit laterally next to the generated laser beam during laser beam welding by supplying the gaseous medium via the feed nozzle and extracting the supplied gaseous medium via the extraction unit.

[0010] The described solution is particularly advantageous for laser beam welding in tight installation spaces, because during laser beam welding, radiation reflections can escape uncontrollably from the joining zone in an unwanted direction, damaging the surrounding environment and / or surrounding component zones of the at least one component to be welded and / or other components. To prevent this, mechanical protective devices are used in the prior art. However, these devices are disadvantageously inflexible and require a large installation space for their positioning, which is not always available. Therefore, such mechanical protective devices are particularly unsuitable for joints with limited accessibility.

[0011] The described solution does not require such mechanical protective devices and therefore enables, in particular even in confined installation spaces, protection of the surrounding environment, surrounding component zones of the at least one component to be welded and / or other components by means of the protective curtain, so that no or only minor damage occurs there, because the protective curtain reflects and / or absorbs laser beams reflected and / or misdirected and / or interfering, in particular from a component area to be welded, and thus keeps them, at least as far as possible, away from the aforementioned areas to be protected.

[0012] The gaseous medium and / or a shape and / or density of the protective curtain formed are / is designed in particular such that the protective curtain reflects and / or absorbs laser beams reflected and / or misdirected and / or interfering from the component area to be welded of at least one component, which in particular have a predetermined wavelength, in such a way that an intensity of laser beams penetrating through the protective curtain is so low that no damage occurs to an environment, in particular positioned behind the protective curtain, and / or to at least one component zone, in particular positioned behind the protective curtain, of the at least one component to be welded and / or to at least one other component, in particular positioned behind the protective curtain.

[0013] In one embodiment, laser beam absorbing particles are or will be introduced into the gaseous medium or into the protective curtain in order to further improve the described protective effect.

[0014] The gaseous medium is particularly homogeneous and compressed. The supply nozzle and the extraction unit are arranged and aligned in such a way that the gaseous medium is blown from the supply nozzle into the extraction unit in a directed manner. This advantageously allows for the realization of a targeted, space-saving laminar protective curtain without gas turbulence.

[0015] In one embodiment, the protective device comprises a welding fume extraction device for extracting welding fumes generated during laser beam welding, and a welding fume supply device connected to the welding fume extraction device and the supply nozzle for supplying the extracted welding fumes as a gaseous medium to the supply nozzle. The welding fume extraction device and the welding fume supply device are connected to one another, for example, via a storage device for storing the extracted welding fumes. This allows process emissions, in particular welding fumes formed in particular by evaporating material, to be extracted and, if present, temporarily stored in the storage device. These devices can be used in a circulating system as a gaseous medium for the protective curtain, since welding fumes are known to absorb the laser radiation used.

[0016] For example, a nozzle shape of the feed nozzle is designed to form a predetermined shape of the protective curtain. Depending on the nozzle configuration, in particular the nozzle shape, of the feed nozzle, a correspondingly shaped protective curtain can be produced, for example, by having a nozzle outlet of the feed nozzle curved, round, or otherwise shaped, thereby forming a correspondingly shaped protective curtain.

[0017] For example, the feed nozzle and / or the extraction unit are movable, and / or the distance between the feed nozzle and the extraction unit is variable. The described solution thus advantageously enables a flexible arrangement of the protective curtain with regard to varying its length and / or other dimensions, since the protective curtain requires less installation space than mechanical protective devices, thus enabling improved accessibility.

[0018] The described solution particularly advantageously enables improved component protection of the surrounding environment and / or the surrounding component zones of at least one component to be welded and / or other components.

[0019] The use of welding fumes as a gaseous medium for the protective curtain, as described above, is particularly advantageous.

[0020] The described solution is particularly suitable for laser welding on metallic components with adjacent thermally sensitive components, for example, for laser welding on inverters or on electrical machines designed as axial-flux machines. For example, laser welding on such axial-flux machines carries the risk of melting adjacent plastic fins during contact welding. The described solution can prevent this or at least significantly reduce the melting of the plastic fins.

[0021] The described solution enables integration into and / or combination with currently available system technology, for example scanner welding optics.

[0022] The described solution can also be combined with protective gas applications.

[0023] Embodiments of the invention are explained in more detail below with reference to drawings.

[0024] Showing: Fig. 1 schematically shows an embodiment of a device for laser beam welding during laser beam welding, Fig. 2 schematically shows an embodiment of the device for laser beam welding according to the invention during laser beam welding, and Fig. 3 schematically shows a further embodiment of the device for laser beam welding according to the invention during laser beam welding.

[0025] Corresponding parts are provided with the same reference numerals in all figures.

[0026] The Fig. 1 to 3 each show an embodiment of a device 1 for laser beam welding. In all illustrated embodiments, the device 1 comprises a laser welding optics 2, via which a laser beam LS, also referred to as a laser processing beam, is directed onto a component connection BV to be welded and, as schematically indicated by a deflection arrow AP, is deflected in particular in at least one direction to create a weld seam.

[0027] During this laser beam welding, radiation reflections SR can adversely escape in an undesired direction from a joining zone in an uncontrolled manner through radiation and in the process damage the surrounding environment and surrounding component zones of at least one component to be welded and / or other components AB, in the example shown at least one neighboring other component AB.

[0028] In order to avoid or at least reduce this risk of damage, the embodiments of the device 1 according to the Fig. 2 and Fig. 3 a protective device 3 with a feed nozzle 4 for supplying a gaseous medium and a suction unit 5 for suctioning the gaseous medium.

[0029] The feed nozzle 4 and the suction unit 5 are arranged and spaced apart from one another in such a way that the gaseous medium fed via the feed nozzle 4 and sucked away by the suction unit 5, ie the gaseous medium flowing from the feed nozzle 4 to the suction unit 5, as schematically shown by flow arrows SP, forms a protective curtain SV between the feed nozzle 4 and the suction unit 5 laterally next to the generated laser beam LS.

[0030] In a method for operating the device 1, during laser beam welding, the protective curtain SV is formed between the feed nozzle 4 and the suction unit 5 laterally next to the generated laser beam LS by feeding the gaseous medium via the feed nozzle 4 and sucking the supplied gaseous medium via the suction unit 5.

[0031] The described solution enables, in particular even in confined installation spaces, protection of the surrounding environment, surrounding component zones of the at least one component to be welded and / or other components AB by means of the protective curtain SV, so that no or only minor damage occurs there, because the protective curtain SV reflects and / or absorbs laser beams LS reflected and / or misdirected and / or interfering from a component area to be welded and thus keeps them away from the aforementioned areas to be protected.

[0032] The gaseous medium and / or a shape and / or density of the protective curtain SV formed are / is designed in particular such that the protective curtain SV reflects and / or absorbs laser beams LS reflected and / or misdirected and / or interfering from the component area to be welded, in particular with a predetermined wavelength, in such a way that an intensity of laser beams LS penetrating through the protective curtain SV is so low that no damage occurs to the surroundings positioned behind the protective curtain SV and / or to at least one component zone of the at least one component to be welded positioned behind the protective curtain SV and / or to at least one other component AB positioned behind the protective curtain SV.

[0033] In one embodiment, particles absorbing laser beams LS are or will be introduced into the gaseous medium or into the protective curtain SV in order to further improve the described protective effect.

[0034] The gaseous medium is homogeneous and compressed. The supply nozzle 4 and the extraction unit 5 are arranged and aligned in such a way that the gaseous medium is blown from the supply nozzle 4 into the extraction unit 5. This creates a targeted, space-saving laminar protective curtain (SV) without gas turbulence.

[0035] A nozzle shape of the feed nozzle 4 is advantageously designed to form a predetermined shape of the protective curtain SV. Depending on the nozzle configuration, in particular the nozzle shape, of the feed nozzle 4, a correspondingly shaped protective curtain SV can thus be produced, for example, by a nozzle outlet of the feed nozzle 4 being curved, round, or otherwise shaped, thereby forming a correspondingly shaped protective curtain SV.

[0036] For example, the feed nozzle 4 and / or the suction unit 5 are movable and / or a distance between the feed nozzle 4 and the suction unit 5 is variable. The described solution thus advantageously enables a flexible arrangement of the protective curtain SV with regard to varying its length and / or other dimensions.

[0037] In the embodiment according to Fig. 3, the protective device 3 comprises a welding fume extraction device 6 for extracting welding fumes SWR generated during laser beam welding and a welding fume supply device 7 connected to the welding fume extraction device 6 and the supply nozzle 4 for supplying the extracted welding fumes SWR as a gaseous medium to the supply nozzle 4. In the example shown according to Fig. 3, this welding fume supply device 7 is shown schematically in a simplified manner as a dashed welding fume supply line.

[0038] The welding fume extraction device 6 and the welding fume supply device 7 are connected to each other, for example, via a storage device 8 for storing the extracted welding fume SWR. In the example shown, this storage device 8 is integrated into a path of the welding fume supply device 7, between the welding fume extraction device 6 and the supply nozzle 4.

[0039] In this example in Fig.In the embodiment shown in Figure 3, process emissions, in particular the welding fume SWR, which is formed in particular by evaporating material, can thus be extracted and optionally temporarily stored in the storage device 8, if present, and can be used in a circulation system as a gaseous medium for the protective curtain SV, since the welding fume SWR is known to absorb the laser radiation used. 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] DE 35 13 501 A1

[0002]

Claims

[1] Device (1) for laser beam welding, comprising a protective device (3) with a feed nozzle (4) for supplying a gaseous medium and a suction unit (5) for sucking out the gaseous medium, characterized by that the feed nozzle (4) and the suction unit (5) are arranged and spaced from one another in such a way that the gaseous medium fed via the feed nozzle (4) and sucked away by the suction unit (5) forms a protective curtain (SV) between the feed nozzle (4) and the suction unit (5) laterally next to a generated laser beam (LS). [2] Device (1) according to claim 1, characterized bythat the gaseous medium and / or a shape and / or density of the protective curtain (SV) formed are / is designed in such a way that the protective curtain (SV) reflects and / or absorbs laser beams (LS) having a predetermined wavelength that are reflected and / or misdirected and / or interfering from a component area of ​​at least one component to be welded in such a way that an intensity of laser beams (LS) penetrating through the protective curtain (SV) is so low that no damage occurs to an environment positioned behind the protective curtain (SV) and / or to at least one component zone of the at least one component to be welded positioned behind the protective curtain (SV) and / or to at least one other component (AB) positioned behind the protective curtain (SV). [3] Device (1) according to one of the preceding claims, characterized bythat laser beam (LS) absorbing particles are introduced into the gaseous medium or into the protective curtain (SV). [4] Device (1) according to one of the preceding claims, characterized by that the gaseous medium is homogeneous and compressed. [5] Device (1) according to one of the preceding claims, characterized by that the feed nozzle (4) and the suction unit (5) are arranged and aligned in such a way that a directed blowing of the gaseous medium from the feed nozzle (4) into the suction unit (5) takes place. [6] Device (1) according to one of the preceding claims, characterized bythat the protective device (3) has a welding fume extraction device (6) for extracting welding fumes (SWR) produced during laser beam welding and a welding fume supply device (7) connected to the welding fume extraction device (6) and the supply nozzle (4) for supplying the extracted welding fumes (SWR) as a gaseous medium to the supply nozzle (4). [7] Device (1) according to claim 6, characterized by that the welding fume extraction device (6) and the welding fume supply device (7) are connected to one another via a storage device (8) for storing the extracted welding fume (SWR). [8] Device (1) according to one of the preceding claims, characterized by that a nozzle shape of the feed nozzle (4) is designed to form a predetermined shape of the protective curtain (SV). [9] Device (1) according to one of the preceding claims, characterized bythat the feed nozzle (4) and / or the suction unit (5) are movable and / or a distance between the feed nozzle (4) and the suction unit (5) is variable. [10] Method for operating a device (1) according to one of the preceding claims, wherein during laser beam welding, by supplying the gaseous medium via the supply nozzle (4) and sucking off the supplied gaseous medium via the suction unit (5), the protective curtain (SV) is formed between the supply nozzle (4) and the suction unit (5) laterally next to the generated laser beam (LS).

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