Methods for welding components

Abstract

The invention relates to a method for welding components (10) in which at least two components (10) are joined together in a joint (11) and subsequently connected by welding a weld seam (12) using a processing laser beam 25 emitted by a welding device 20, wherein a surface of the joint (11) is scanned before welding by a measuring beam (26) emitted by a measuring beam unit (23) and analyzed in a control / computing unit (21), wherein a geometric state of the surface of the joint (11) is detected, wherein - the detected geometric state is evaluated and categorized as ‘not OK’ (32a) or as ‘OK’ (32b) (32), and - if the geometric condition is categorized as ‘not OK’ (32a), the surface of the joint (11) is processed using the processing laser beam (25) and then all previous steps are repeated, and, - if the geometric condition is categorized as “in order” (32b), the components (10) are joined together by welding (24) using the processing laser beam (25).

Description

[0001] The invention relates to methods for welding components with a detection and modification of component states prior to welding preparation.

[0002] DE 10 2025 122 923 A1 discloses a method for welding components, in which at least two components are joined in a joint and subsequently connected by welding a weld seam using a welding laser beam emitted from a welding device, wherein the joint is photographically recorded before and / or during welding or scanned by a measuring beam emitted from a measuring beam unit and analyzed in a control / computing unit, wherein a geometric state and / or a material state is detected, a welding program adapted to the determined geometric state is individually selected from a database, and the welding is carried out according to the selected welding program, and during welding the welding laser beam and the measuring beam are emitted and are jointly aligned and tracked depending on the determined geometric state.that the measuring beam is directed into a forming vapor capillary in the ideal measuring position determined for this purpose and / or with the ideal measuring configuration.

[0003] The laser welding process requires sufficient component quality upon entry as well as acceptable process boundary conditions. This concerns, on the one hand, the surface finish and, on the other hand, for example, height differences, offsets and gaps between the components to be welded.

[0004] Optical coherence tomography (OCT) is a measurement technique that can obtain two- and three-dimensional images of component surfaces with micrometer resolution. OCT systems help in the detection and monitoring of morphological changes. Therefore, OCT systems, which function based on the reflection of the OCT measurement beam from the components, are also used to measure the surfaces of components to be welded.

[0005] Insufficient surface quality can lead to multiple reflections and measurement noise, which significantly impairs the quality and accuracy of the measurement. Furthermore, the measurement can severely disrupt the automated process in a production plant and lead to a plant shutdown. According to the current state of the art, plausible measurement results cannot be generated in the case of multiple reflections, which considerably complicates the use of OCT in automated systems for such measurement applications.

[0006] The invention is based on the objective of identifying and positively influencing adverse component conditions of components to be welded during welding preparation, before the components are welded, and thereby increasing the quality of the weld.

[0007] The problem is solved according to the invention by a welding preparation method having the features of the characterizing part of claim 1.

[0008] Advantageous embodiments of the invention are the subject of the dependent claims.

[0009] According to the invention, a method for welding components is proposed in which at least two components are joined in a joint and subsequently connected by welding a weld seam using a processing laser beam emitted from a welding device, wherein a surface of the joint is scanned before welding by a measuring beam emitted from a measuring beam unit and analyzed in a control / computing unit, wherein a geometric state of the surface of the joint is detected, wherein the detected geometric state is evaluated and categorized as "OK" or "not OK", and, if the geometric state is categorized as "not OK", the joint surface is processed using the processing laser beam and then all previous steps are repeated, and, if the geometric state is categorized as "OK",The components are joined together by welding using the processing laser beam.

[0010] The proposed method enables the application of OCT measurement even to highly reflective components, such as those made of copper. Only minimal component preparation is required, for example, regarding cut edge quality, surface contamination, and so on. In other words, higher tolerances are permissible in the upstream processes, resulting in reduced effort and lower costs. The method's improvement in component quality leads to a reduction in scrap. The depth information obtained from the OCT measurement enables a new form of component preparation for laser welding, such as adaptive adjustment of the welding optics' focus position.

[0011] The method according to the invention can be implemented using current plant and system technology and exhibits good integrability into existing processes as well as being particularly suitable for detecting and joining rod-shaped component connections, such as hairpins of an electric motor. Furthermore, the method is flexible with regard to materials and material conditions.

[0012] According to the invention, the OCT system used for weld preparation can also be used in a subsequent 100% online quality assurance process during welding, for example by continuously measuring weld penetration depth, weld geometry and so on.

[0013] The method is applicable regardless of the joint geometry (lap joint, butt joint, fillet weld, etc.) and is easily automated. The novel preparation process according to the invention thus replaces manual component preparation tasks.

[0014] Exemplary embodiments of the invention are explained in more detail below with reference to drawings.

[0015] This shows: Fig. 1 schematically a first embodiment of the method according to the invention, and Fig. 2 schematically illustrates the process of the first embodiment of the method according to the invention.

[0016] Corresponding parts are marked with the same reference symbols in all figures.

[0017] Fig. Figure 1 shows in a first step the scanning and measurement 31 of a surface of the joint 11 of two components to be welded 10 as well as the analysis and categorization 32 of the geometric state of the joint 11.

[0018] A welding device 20 comprises a measuring beam unit 23, a scanner optics 24 and a control / computing unit 21 with a database 22.

[0019] The measuring beam unit 23 emits a measuring beam 26, which is guided by the scanner optics 24 over the joint 11 and scans it. The reflected measuring beam 26 is detected by the control / processing unit 21, and the geometric state of the joint 11 is subsequently analyzed and categorized 32 as "not OK" 32a or as "OK" 32b.

[0020] In the present case, the geometric condition is categorized as “not OK” 32a, which is why in a second step the surface of the joint 11 is processed 33 by the processing laser beam 25, which is emitted by the welding device 20.

[0021] In a third step, the measuring beam 26 is again guided through the scanner optics 24 over the joint 11 and this is scanned 31 and subsequently the geometric state of the joint 11 is analyzed and categorized 32.

[0022] Through processing 33, the geometric state can now be categorized as "OK" 32b, which is why, in a fourth step, welding 34 is carried out according to a selected welding program. The welding device 20 emits a processing laser beam 25 for this purpose. The processing laser beam 25 welds the components 10 together, whereby a weld seam 12 forms at the joint 11.

[0023] In Fig. Figure 2 shows the method according to the invention schematically in a flowchart.

[0024] In a first step, a scanning and measurement 31 of the joint 11 takes place.

[0025] In a second step, an analysis and categorization 32 of the joining joint 11 takes place.

[0026] If the geometric state of the joint 11 is categorized as "not OK" 32a, processing 33 follows, after which the preceding steps are repeated. This loop is repeated until the geometric state of the joint 11 is categorized as "OK" 32b.

[0027] If the geometric state of the joint 11 has been categorized as “OK” 32b, welding 34 is carried out to join the components 10 together by a weld seam 12. This completes step 35 of the process. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2025 122 923 A1

[0002]

Claims

[1] Method for welding components (10) in which at least two components (10) are joined together in a joint (11) and subsequently connected by welding a weld seam (12) using a processing laser beam 25 emitted from a welding device 20, wherein a surface of the joint (11) is scanned before welding by a measuring beam (26) emitted from a measuring beam unit (23) and analyzed in a control / computing unit (21), wherein a geometric state of the surface of the joint (11) is detected, characterized by , that, - the detected geometric state is evaluated and categorized as ‘not OK’ (32a) or as ‘OK’ (32b) (32), and - if the geometric condition is categorized as ‘not OK’ (32a), the surface of the joint (11) is processed using the processing laser beam (25) and then all previous steps are repeated, and, - if the geometric condition is categorized as “in order” (32b), the components (10) are joined together by welding (24) using the processing laser beam (25). [2] Method according to claim 1, characterized by , that if the geometric condition is categorized as “OK” (32b), prior to welding (34) the welding device (20) is prepared by determining focusing settings for the processing laser beam (25) over the surface of the joint (11) and positioning the processing laser beam (25) relative to the surface of the joint (11) for the subsequent welding (34). [3] Method according to claim 1 or 2, characterized by, that depending on the geometric state of the surface of the joint (11) operating parameters for the processing laser beam (25) are selected and set. [4] Method according to claim 3, characterized by , that operating parameters for the processing laser beam (25) are selected from a database (22).

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