Method for joining components by laser welding using a laser welding device

Abstract

One aspect of the invention relates to a method for joining components (14, 16) by laser welding using a laser welding device, in which a first component (14) and a second component (16) are arranged next to each other along their respective longitudinal sides (18, 20) and are welded together by laser welding in the region of their respective end faces (22, 24), wherein a respective conduit (28) for a medium (30) is arranged within the respective components (14, 16), which extends along the longitudinal direction (x) of the respective component (14, 16), and wherein the components (14, 16) are welded together to form an intermediate conduit (34, 54) which fluidically connects the respective conduits (28).For this purpose, the components (14, 16) are welded together to form an intermediate line (34, 54) that fluidically connects the respective lines (28), wherein a basin-shaped receptacle is attached in the region of the two end faces (22, 24) by means of a cover element (36), and the basin-shaped receptacle is produced by attaching a wall (32, 52) that encloses the end faces and the outlet openings (29) of the respective lines (28) on its outer circumference. According to the invention, the wall (32, 52) is produced by placing a wire element (26) and welding the wire element (26) on in successive layers, or by placing one or more templates (50) corresponding to the end faces (22, 24) and welding the templates (50) on.

Description

[0001] The invention relates to a method for joining components by laser welding using a laser welding device according to the preamble of claim 1.

[0002] As is already known, for example, from the publication DE 10 2021 001 980 A1, there are various methods for welding hair pins, each following different approaches.

[0003] Components such as hairpins are typically made of solid conductive material, especially copper, so they can usually be welded together simply by melting the material. However, connecting hairpins to internal cooling lines requires a method that allows fluid flow in addition to electrical flow, which is not possible with conventional eyelet welding methods. The concept of internal cooling for winding lines or hairpins can be found, for example, in German patent application DE 10 2017 119 033 A1. This document describes a waveguide as the winding or hairpin, which is typically connected to the cooling system via terminals, plugs, or connectors, often to a manifold or inlet.

[0004] The generic document DE 10 2019 202 626 A1 describes a method for repairing solder joint leaks on a connection device designed to introduce cooling water into hollow metallic stator bars of a stator winding of an electrical machine.

[0005] DE 10 2021 206 370 A1 also shows a stator winding of a stator which has several hairpin-shaped conductor elements that must be conductively connected to each other to form an electrical connection. The hairpin-shaped conductor elements are designed as waveguides, with a cover having a cavity, which is placed on the ends of the waveguides in pairs, also connecting them fluidically and thus forming a continuous channel for coolant flow.

[0006] The object of the invention is to provide a method by which internal temperature control of the components is not prevented during the joining of components.

[0007] This problem is solved by a method with the features of claim 1. Advantageous further developments and embodiments of the invention can be found in the dependent claims and the description of the figures.

[0008] One aspect of the invention relates to a method for joining components, in particular hair pins, by laser welding using a laser welding device or a corresponding apparatus that enables laser welding. In this method, a first and a second component are arranged next to each other along their respective longitudinal sides and joined at their end faces by laser welding. This means that the components, or the hair pins, are welded or joined together at their front end faces along their longitudinal extent upwards. The components or hair pins shown here each include a conduit for a medium through which the medium can be passed to enable temperature control, in particular cooling, of the components. These conduits extend along the longitudinal extent of the respective components.

[0009] To solve the problem of the invention and provide a media line or a line for the medium, the invention provides that the components are welded together to form an intermediate line that fluidically connects the respective lines. The outlet openings of the lines, located at the end faces, are connected to each other. This connection must be made in such a way that a medium can flow from one line to the other, thus providing a continuous cooling system. This means that the medium must pass through one line into the second. To enable this, an intermediate line must be provided, particularly at the end faces, so that the outlet openings are conductively connected to each other. Furthermore, current can flow through the welded connection during operation. Additionally, the components in the front area or...The components are connected at their end faces. For this purpose, an intermediate line is provided and the weld connection is made. In other words, an intermediate line is arranged in the front end face area of ​​the components, through which the medium can flow from one component to the other within the lines.

[0010] According to the invention, a basin-shaped receptacle is provided or manufactured in the area of ​​both end faces, over which a cover element is attached or manufactured. This means that the end faces are extended circumferentially with material in such a way that a basin or basin-shaped receptacle is provided in the area of ​​the end faces. If, for example, a medium or fluid were to exit through a pipe, the basin-shaped receptacle would prevent the medium from flowing down the end faces and then down the outer surfaces of the components, but would instead hold it in the receptacle and introduce it into the second pipe. Accordingly, the medium would pass through the outlet opening into the second outlet opening, with the cover element positioned above the receptacle so that the medium can only enter the corresponding outlet opening and cannot overflow and thus escape.In other words, an extension of the outer surfaces of the components is provided, through which the outlet openings are connected to each other and closed with a cover element, so that the medium can only flow in one direction, namely from one outlet opening to the other, regardless of any adjustment, movement or positioning of the respective components.

[0011] According to the invention, the basin-shaped receptacle is further provided by attaching a wall circumferentially enclosing the end faces and outlet openings of the respective conduits. This wall is thus designed to receive, or provide, the receptacle for the medium. The wall can be configured such that it, for example, extends the conduits but allows a transition between the respective outlet openings, through which the medium can flow from one outlet opening to the other.

[0012] According to a first embodiment of the invention, the wall is produced by placing a wire element and successively welding it in place. In this embodiment, a particularly thin wire element is used, which is placed circumferentially on the outer surface of the end face, thus creating a raised wall and providing a receptacle for the medium, for example, a cooling fluid, particularly water, which can exit the outlet opening and flow into the next outlet opening. The wall thus allows the medium to overflow and be directed from the outlet opening to the edges of the end face, ensuring that the medium flows only towards the next outlet opening.

[0013] According to a second embodiment of the invention, the wall is produced by placing a template corresponding to the end faces and welding the template in place. The template, in particular, comprises a geometry corresponding to the end face of the respective components and a height that is already sufficient for the transition from one outlet opening to the other outlet opening of the medium. Such a template is particularly easy to manufacture and can therefore be easily placed on the end face and welded. One or more templates can be applied in layers using laser beam welding.

[0014] In a further advantageous embodiment of the invention, the wall is also produced on the respective front edge of the components, which encompasses the outlet opening. The idea behind this is that the wall is particularly small and particularly high in relation to the front edge, so that the medium can easily exit one outlet opening and enter the next. If, for example, the wall were not large enough or not high enough, a poorly executed weld of the cover element could, for instance, lead to the destruction of the intermediate channel provided by the wall and the cover element, as material or welding material could clog the outlet openings. Therefore, sufficient space or volume is provided through which the medium can flow in the intermediate channel.

[0015] In a further advantageous embodiment of the invention, the cover element has a concave recess and an edge region, the edge region being placed against the wall. The concave recess of the cover element provides an even larger intermediate channel to facilitate a smoother and more efficient transition from one outlet opening to the other. By placing the cover element against the wall, particularly through the use of the edge region, a particularly strong weld between the cover element and the recess is achieved.

[0016] In a further advantageous embodiment of the invention, it is provided that the wall placed on the adjacent components is welded to the components circumferentially on the outside. In other words, a laser, or the laser welding device, or the laser welding apparatus is to be used in such a way that a gap between the placed wall and the components, or the end face, is welded together by means of laser welding.

[0017] In a further advantageous embodiment of the invention, the cover element placed on the wall is welded to the wall circumferentially on its outer surface. Similar to the previously mentioned embodiment, where the wall was placed on the components, the cover element is now also placed on the wall and welded circumferentially on its outer surface by laser welding. The laser welding process is particularly precise in order to weld the very small components together.

[0018] In a further advantageous embodiment of the invention, a laser beam of the laser welding device is positioned transversely to the longitudinal direction of extension of the components. In particular, it is possible to move the laser beam relative to the components in various degrees of freedom, thus enabling different angular settings. Furthermore, it should be possible to adjust the laser beam, especially circumferentially around the outside of the components, so that the respective gaps between the components and the wall, and between the wall and the cover element, can be welded together particularly efficiently.

[0019] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0020] This shows: Fig. 1. A diagram illustrating a method for joining two components in one possible embodiment; and Fig. 2 Another diagram showing a further development of the procedure using templates.

[0021] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0022] Fig. Figure 1 shows a diagram illustrating a method for joining components 14, 16 by laser welding using a laser beam device. In this method, a first component 14 and a second component 16, which are specifically designed as hair pins, are arranged next to each other along their respective longitudinal sides 18, 20 and welded together by laser welding in the region of their respective end faces 22, 24. The laser beam device itself is not shown here for a better view of the components 14, 16, but can easily be imagined. It is provided that a conduit 28 for a medium is arranged within each component 14, 16, extending along the longitudinal direction of the respective components 14, 16.In order to enable the medium to be conveyed from one line 28 to the other 28, it is provided according to the invention that the components 14, 16 are welded together to form an intermediate line 34 which fluidically connects the respective lines 28.

[0023] According to this, it shows Fig. 1. The method, in particular for fluidic and electrical connection of the two components 14, 16 by laser welding, in which a wire element 26 is used to produce a wall 32. The components 14, 16 are arranged next to each other along their longitudinal sides 18, 20 and are joined together at their end faces 22, 24 by laser welding, whereby the formation of the intermediate line 34 is also initially provided. The line 28 for the medium 30, which extends longitudinally to the components 14, 16, thus runs in each of the components 14, 16. To provide the fluidic connection between the lines 28, the wire element 26 is placed on the end faces 22, 24 and attached to them by laser welding. The wire element 26 forms a circumferential wall 32 by means of its successive welding, around the end faces 22, 24 and around the exit openings 29 of the lines 28.This wall 32 thus constitutes a defined space that can be used as an intermediate channel 34. The intermediate channel 34 is designed to enable a fluidic connection between the channels 28 of the two components 14 and 16, allowing the medium 30 to flow unimpeded from one component 14 to the other component 16. The wall 32, which is formed by the wire element 26, ensures that the outlet openings 29 of the channels 28 are completely enclosed, preventing any medium from escaping and allowing the medium 30 to be transported in a controlled manner within the intermediate channel 34. Laser welding of the wire element 26 shown here creates a strong bond between the end faces and the wire element. The plan is to apply a cover element 36 to the wall 32 by welding the wire element in layers.

[0024] The cover element 36 is thus formed from the wall 32 created by the wire element 26 and welded together to close and seal the intermediate line 34. The cover element 36 has, for example, a concave recess 38 that fits precisely onto the wall 32 and completely covers it. The edge region 40 of the cover element 36 is applied to the upper edge of the wall 32 and then connected to the wall 32 circumferentially on the outside by laser welding. This connection allows the intermediate line 34 to be completely enclosed, so that the medium 30 can flow safely and without leakage from one component 14 to the other component 16. The cover element 36 thus provides an additional structural connection for the intermediate line, or forms / createsThis closes so that the medium 30 can be sealed and conveyed from one outlet opening 29 to the other, and can also transfer the current from one component 14 to the other component 16.

[0025] Fig. Figure 2 shows an alternative embodiment of the method or the fluidic electrical connection via the intermediate conductor 34 for the respective components 14 and 16. Here, a template 50 is used instead of the wire element 26, but it performs the same function as the wire element. The components 14 and 16 are therefore connected as described in Figure 2. Fig. 1 along their longitudinal sides 18, 20 are arranged next to each other and are joined by laser welding in the area of ​​their respective end faces 22,24.

[0026] In the embodiment shown here, the template 50, which precisely replicates the shape of the end faces 22, 24 and the outlet openings 29 of the lines 28, is placed onto the end faces 22, 24 of the components 14, 16. The template 50 forms a circumferential wall 52 that completely encloses the end faces 22, 24 and the outlet openings 29. The wall 52 shown here, in turn, creates the newly designed intermediate line 54, which fluidically connects the lines 28 of the respective components 14, 16.

[0027] The lid element 36 is, as in Fig.As described in Figure 1, the structure is formed by welding one or more individual templates 50 or walls 52 arranged layer by layer. The edge region 40 of the cover element 36 is placed on the upper edge of the wall 52 and is also connected to the wall 52 by laser welding. This hermetically seals the intermediate line 54, allowing the medium 30 to be safely conveyed from one component 14 to another component 16, in particular via the respective outlet openings 29 of the respective lines 28. The template 50, therefore, enables a sealed connection between the respective components 14 and 16, and thus the fluidic-electrical connection, due to its precise fit.

[0028] In particular, a laser beam 60, used for laser welding the components 14, 16, can be directed either in a position transverse to the longitudinal axis of the components or at an angle to the weld points. In the transverse arrangement, the laser beam 60 strikes the end faces 22, 24 of the components perpendicularly, thus providing a uniform weld seam along the entire joint line. Alternatively, the laser beam 60 can also strike the weld points at an angle, which is particularly applicable for complex geometries and / or layer-by-layer build-up. However, it is specifically intended that the laser beam 60 can be directed transversely to the longitudinal direction of the respective components 14, 16.If the laser beam 60 strikes the edges on the end faces 22, 24 perpendicular to the longitudinal extension direction of the components 14, 16, a particularly uniform weld seam can be achieved along the connection line or the gaps between end faces 22, 24, wall 52 and cover element 36.

[0029] In summary, a method is proposed that establishes an electrical and fluidic connection between two hairpins. The hairpins are arranged such that a cap with a cavity, representing the intermediate conductor, is created by layering or continuously applying material. This cavity is designed to connect the two internal cooling lines or conductors 28 of the hairpins or components 14, 16, while the cap or cover element itself ensures the electrical connection between the hairpins. The material can be applied, in particular, by soldering, welding, or even by 3D printing.The resulting layers or strata can be designed either as a flat frame that converges in shape and size to close the connections, or as wire or material applied along the outer edge of the hairpin ends. In particular, the process must ensure that the applied material is electrically conductive and that the outer surface of the cover element remains sealed to enable a closed cooling circuit. This allows the medium or cooling medium to be efficiently transferred from one hairpin or component to another. Reference symbol list 14 First component 16 Second component 18 Long side 20 Long side 22 Front 24 Front 26 wire element 28 Line (for medium) 29 Exit opening 30 Medium 32 wall 34 Intermediate line 36 lid element 38 Concave Reception 40 Edge area 50 stencils 52 wall 54 Intermediate line 60 laser beam

Claims

[1] Method for joining components (14, 16) by laser welding using a laser welding device, in which a first component (14) and a second component (16) are arranged next to each other along their respective longitudinal sides (18, 20) and are welded together by laser welding in the region of their respective end faces (22, 24), wherein a respective conduit (28) for a medium (30) is arranged within the respective components (14, 16), which extends along the longitudinal direction (x) of the respective component (14, 16), wherein the components (14, 16) are welded together to form an intermediate line (34, 54) which fluidically connects the respective lines (28), wherein a basin-shaped receptacle is attached in the area of ​​the two end faces (22, 24) by means of a cover element (36), and wherein the basin-shaped receptacle is produced by attaching a wall (32, 52) circumferentially enclosing the end faces (22, 24) and the outlet openings (29) of the respective conduits (28), characterized by , that the wall (32) is produced by placing a wire element (26) and welding the wire element (26) on in successive layers, or the wall (52) is produced by placing one or more templates (50) corresponding to the end faces (22, 24) on and welding the template (50) on. [2] Method according to claim 1, characterized by , that the wall (52) is produced on a respective front edge of the respective components (14, 16) encompassing the exit openings (29). [3] Method according to claim 1, characterized by, that the lid element (36) has a concave recess (38) and an edge area, the edge area being placed on the wall (32, 52). [4] Method according to claim 1, characterized by , that the wall (32, 52) placed on the adjacent components (14, 16) is welded to the components (14, 16) on the outer circumference. [5] Method according to any one of the preceding claims, characterized by , that the cover element (36) applied to the wall (32, 52) is welded to the wall (32, 52) on its outer circumference. [6] Method according to any one of the preceding claims, characterized by , that a laser beam (60) of the laser welding device is positioned transversely to the longitudinal extension direction (x) of the components (14, 16).

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