DE102021210166A1 - Welding device, processing device and method for producing a weld seam on an object to be welded - Google Patents

Abstract

The present invention creates a welding device (10) comprising at least one laser device (1) and/or an electron beam device (2), with which a welding beam can be generated and can be aligned to a region of a welding object (VO) to be welded and through which a weld seam can be produced the welding object can be generated; a holding device (3) with which the object to be welded (VO) can be held in a welding position, wherein in the welding position a laser beam is applied by the laser device (1) and/or an electron beam by the electron beam device (2) as a welding beam onto the object to be welded (VO) can be aligned to the object to be welded (VO) from a first side and/or from a second side.

Description

The present invention relates to a welding device, a processing device and a method for producing a weld seam on an object to be welded.

State of the art

When using known welding methods and welding devices, two or more thin metal sheets or foils can be welded in an overlapping manner. Laser beam welding or electron beam welding can usually be used in order to be able to better adjust the energy input and thus reduce the effects of warping of thin components. A laser or electron beam is usually used, which hits a horizontal component from above.

In order to produce a fuel cell stack, it is usually necessary for many pairs of bipolar plates, which are designed as flat or embossed, thin metal sheets, some of which are provided with surface structures, to be welded to one another in an overlapping manner. It may be necessary for this weld to be gas-tight. The weld seams can sometimes be very long (roughly more than 1 m per pair of bipolar plates). The areas of the two metal sheets to be welded should usually fit closely together and ideally not have a gap.

The metal sheets can be pressed against each other directly at the welding point or, alternatively, they can be pulled against each other by means of air evacuation from the intermediate gap. In most cases, the sheets can be positioned and clamped horizontally on a belt, an axle, or a welding device. A laser beam used for welding can radiate onto the workpiece from above, with the underside of the workpiece usually being able to be covered by the support surface.

In the EP 2 919 942 B1 describes a welding process for joining two workpieces.

Disclosure of Invention

The present invention provides a welding device according to claim 1, a processing device according to claim 7, and a method for making a weld on a welding object according to claim 8.

Preferred developments are the subject of the dependent claims.

Advantages of the Invention

The idea on which the present invention is based is to specify a welding device, a processing device and a method for producing a weld seam on a welding object, wherein the creation of a weld seam or processing can be simplified and accelerated and the stability of the weld seam can be improved.

The pressing of two bipolar plates to be welded can be carried out in such a way that all weld seams can be set at the same time without having to re-clamp / reposition the pressing unit (holding device). As a result, a cycle time of the laser or electron beam device, in particular of the welding, can be shortened, component distortion can be minimized, since the weld seam can be composed of alternating sections which, for example, alternately connect to one another on two different sides of the object to be welded and can form a continuous weld contour. Furthermore, parallelization of the laser welding process can be made possible.

According to the invention, the welding device comprises at least one laser device and/or an electron beam device, with which a welding beam can be generated and which can be aligned to a region of an object to be welded and by which a weld seam can be generated on the object to be welded; a holding device with which the object to be welded can be held in a welding position, wherein in the welding position a laser beam can be aligned by the laser device and/or an electron beam by the electron beam device as a welding beam onto the object to be welded from a first side and/or onto the object to be welded from a second side is.

The laser device and/or an electron beam device can also be used to generate a plurality of welding beams, which can be directed onto the object to be welded from different sides simultaneously or one after the other.

The welding device can be used to weld various objects to be welded, such as bipolar plates for fuel cells (used as a stack, but also as an electrolyser), in the field of battery production, as well as in all applications where thin metal sheets are welded and joined together during the welding process should be pressed.

Workpieces, such as bipolar plates, can be welded from both flat sides at the same time. For this purpose, the holding device (pressing device) can be designed in such a way that the welding contour can be accessible from both flat (opposite) sides. However, each weld seam can not be accessible from both sides but from one side - the accessibility can be alternating from different sides. It can thus be achieved that the holding device can be implemented structurally in such a way that the workpieces, such as metal sheets, can be pressed along the entire welding point. The exact positioning of the bipolar plates can be vertical, horizontal or even at an angle in space. The laser radiation can be accessed from both flat sides of the object to be welded. The use of two or more laser sources can halve or further reduce the cycle time.

Another significant advantage can be achieved by selectively setting the weld seams on the front and on the back (first and second side) of the welding object with several welding beams at the same time or at different times, whereby the distortion of the component can be minimized.

The welding device can be designed simply and be handled quickly. There is no need to create a vacuum between the plates. The contact pressure can be checked using sensors, for example as part of a process control.

According to a preferred embodiment of the welding device, the holding device is designed to hold such a welding object, which comprises a first workpiece and a second workpiece and these two workpieces can be connected to one another by the weld seam, the first workpiece and the second workpiece being at least partially in the region of the weld overlap.

The welding device can advantageously be used to weld overlapping workpieces, such as thin metal sheets for fuel cells.

According to a preferred embodiment of the welding device, the holding device comprises a first holding area and a second holding area, wherein the first holding area can be attached to a first side of the object to be welded and the second holding area can be attached to a second side of the object to be welded.

With the two holding areas, the workpieces can be held better and more easily and welded more easily and effectively at the intended location.

According to a preferred embodiment of the welding device, the first workpiece corresponds to the first side of the object to be welded and the second workpiece corresponds to the second side of the object to be welded, and the holding device is set up and positioned in such a way that the first holding area presses the first workpiece toward the second workpiece and to press the second workpiece towards the first workpiece with the second holding area.

Due to the holding device, the two workpieces can advantageously be arranged and welded close together.

According to a preferred embodiment of the welding device, the first holding area includes a first cutout through which the welding beam can be applied to the first side of the object to be welded, and the second holding area includes a second cutout through which the welding beam can be applied to the second side of the object to be welded.

The two recesses allow welding seams to be applied to the workpieces from both sides, advantageously in the areas where it is desired to attach the two workpieces to one another.

According to a preferred embodiment of the welding device, the first cutout and the second cutout represent a weld seam course that is continuous in some areas or a closed weld seam contour along a projection direction perpendicular to the first side and to the second side.

The two recesses can each and in combination represent a contour of the course of the weld seam or sections thereof, that is to say they can comprise several areas over a surface of the respective workpiece. In other words, the projection direction can be a plan view of a surface of the workpiece, and in this plan view the visible first weld seam of the upper workpiece with its first areas and the second weld seam added in projection from the lower workpiece with the second areas in combination with the first weld seam form a continuous weld seam/weld contour in plan view.

According to the invention, a processing device comprises at least one laser device and/or an electron beam device with which a processing beam can be generated and an area to be processed of a processing object can be aligned; a holding device with which the processing object can be held in a processing position, wherein in the processing position a laser beam can be directed by the laser device and/or an electron beam by the electron beam device onto the processing object from a first side and/or onto the processing object from a second side.

The processing can include cutting, soldering and/or other processes, for example.

Within the scope of this invention, any wording relating to the welding design, for example the welding object or the weld seam or others, can also be related to the processing and the associated components or process steps, such as a processing object or others. All the exemplary embodiments mentioned for the welding versions can also apply analogously to the more general processing versions and to the processing device.

According to the invention, in the method for producing a weld seam on an object to be welded, a welding device according to the invention is provided S1; providing S2 a welding object; holding S3 the welding object in a welding position by the holding device; generating S4 and aligning a welding beam onto an area of the welding object to be welded, wherein in the welding position a laser beam is projected through the laser device and/or an electron beam through the electron beam device as a welding beam onto the welding object from a first side and/or from a second side onto the welding object is aligned; and generating S5 a weld seam on the welded object.

In order to hold the object to be welded, it may be possible for the clamped workpieces to be moved in the holding device and for the welding to be carried out during this movement (so-called on-the-fly welding).

According to a preferred embodiment of the method, such a welding object is held, which comprises a first workpiece and at least one second workpiece and these workpieces are connected to one another by the weld seam, with the first workpiece and the at least one second workpiece overlapping at least in regions in the region of the weld seam.

Several further workpieces can also be located between the first and a second workpiece, for example in at least a partial overlap.

According to a preferred embodiment of the method, the first holding area is attached to a first side of the welding object and the second holding area is attached to a second side of the welding object and the first workpiece corresponds to the first side of the welding object and the second workpiece corresponds to the second side of the welding object and with With the first holding area, the first workpiece is pressed towards the second workpiece and with the second holding area, the second workpiece is pressed towards the first workpiece.

According to a preferred embodiment of the method, the welding beam is applied to the first side of the object to be welded through a first cutout in the first holding area and the welding beam is applied to the second side of the object to be welded through a second cutout in the second holding area, with the first cutout and the second cutout being in a projection direction perpendicular to the first side and to the second side, represent a partially continuous weld seam or a closed weld seam contour and a partially continuous weld seam or a closed weld seam contour is generated in this projection.

According to a preferred embodiment of the method, when a welding position is assumed, a first weld seam is produced on the first side in one or more first areas and a second weld seam is produced on the second side in one or more second areas, with the first and second areas adjoin each other alternately and a closed weld seam contour is produced.

In this case, “alternating” can be understood to mean that the weld seam along its course is formed in sections from the first side and in between, before or after it is formed from the second side and/or vice versa.

By advantageously pressing the workpieces together and applying the welding beam to both sides, advantageously without detaching the object to be welded from the holding device, the welding beam can be guided over the first workpiece and/or the second workpiece and at least in a specific section in the direction of projection be consistent. A first weld seam can thus run in the first area fen and at the end of which the second weld seam is connected to the second side on the second workpiece, in the projection on top of one another then forming a weld seam that is continuous in projection at this transition from the first to the second side. As a result, the object to be welded cannot be unclamped from the holding device when the weld seam is produced, and the stability of the weld point can be increased. Furthermore, a cycle time of the laser beam device and/or the electron beam device can be shortened and warping of the welding object can be reduced.

The welding device and/or processing device can also be characterized by the features mentioned in connection with the method and its advantages and vice versa.

The welding device can also be distinguished by the features mentioned in connection with the processing device and its advantages, and vice versa.

Further features and advantages of embodiments of the invention result from the following description with reference to the accompanying drawings.

character list

The present invention is explained in more detail below with reference to the exemplary embodiments given in the schematic figures of the drawing.

• 1 eine schematische Darstellung einer Schweißvorrichtung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung;
• 2 eine schematische Darstellung einer erzeugten Schweißnaht in beiden Seiten durch eine Schweißvorrichtung gemäß einem Ausführungsbeispiel der vorliegenden Erfindung; und
• 3 eine Blockdarstellung von Verfahrensschritten des Verfahrens zum Herstellen einer Schweißnaht an einem Verschweißobjekt gemäß einem Ausführungsbeispiel der vorliegenden Erfindung.

Show it:

• 1 a schematic representation of a welding device according to an embodiment of the present invention;
• 2 a schematic representation of a weld seam produced in both sides by a welding device according to an embodiment of the present invention; and
• 3 a block diagram of method steps of the method for producing a weld seam on a weld object according to an embodiment of the present invention.

In the figures, the same reference symbols denote the same elements or elements with the same function.

1 shows a schematic representation of a welding device according to an embodiment of the present invention.

The welding device 10 comprises at least one laser device 1 and/or an electron beam device 2, with which a welding beam can be generated and can be aligned to a region of a welding object VO to be welded and by means of which a weld seam can be produced on the welding object; a holding device 3, with which the object to be welded VO can be held in a welding position, wherein in the welding position a laser beam is directed through the laser device 1 and/or an electron beam through the electron beam device 2 as a welding beam onto the object to be welded VO from a first side A and/or from a second side B can be aligned with the object to be welded VO. The laser device 1 and/or an electron beam device 2 are shown only schematically, with a separate laser device 1 and/or an electron beam device 2 being able to be present on each side of the welding object VO, or the welding device 10 being able to comprise only one laser device 1 and/or electron beam device 2. the beam of which can then be aligned to a respective side or to both sides A and B of the object to be welded VO, in chronological succession or simultaneously.

The two braced sheets W1 and W2 are shown in cross section. The holding device 3 with pressure masks for the workpieces W1 and W2 can be designed in such a way that the welding points are pressed on from all sides and welding through and/or welding is still possible.

The holding device 3 can be shaped in such a way as to hold such a welding object VO, which comprises a first workpiece W1 and a second workpiece W2 and these two workpieces can be connected to one another by the weld seam, the first workpiece W1 and the second workpiece W2 being at least partially connected overlap in the area of the weld. The holding device 3 can include a first holding area 3a and a second holding area 3b, it being possible for the first holding area 3a to be attachable to a first side A of the object to be welded VO and the second holding area 3b to be attachable to a second side B of the object to be welded VO. The first workpiece W1 can correspond to the first side A of the object to be welded VO and the second workpiece W2 can correspond to the second side B of the object to be welded VO and the holding device 3 can be set up and positioned in such a way that the first workpiece W1 can be held with the first holding area 3a to the second to push the workpiece W2 and to push the second workpiece W2 toward the first workpiece W1 with the second holding portion 3b. A gap L can remain between the first workpiece W1 and the second workpiece W2, or they can lie directly against one another.

The first holding area 3a can include a first cutout A1, through which the welding beam can be applied as the first welding beam ST1 to the first side A of the object to be welded VO, and the second holding area 3b can include a second cutout A2, through which the welding beam can be applied as the second welding beam ST2 can be applied to the second side B of the welding object VO, simultaneously or sequentially. The first recess A1 and the second recess A2 can be viewed from a projection direction P, for example a plan view of the surface of the first or second workpiece, perpendicular to the first side A and the second side B, a weld seam that is continuous in some areas or a closed one Display weld contour K ( 2 ). The first welding beam ST1 can then form a first weld seam SN1 in areas of the first workpiece W1 and the second welding beam ST2 can then form a second weld seam SN2 in areas of the second workpiece W2.

2 shows a schematic representation of a weld seam produced in both sides by a welding device according to an embodiment of the present invention.

In the 2 a top view of the first or second workpiece W1 (W2) is shown, which can be a thin metal sheet of a fuel cell. The weld seam as a weld contour can be composed of the sections of the first weld seam SN1 and the second weld seam SN2, wherein in the first and second regions B1 and B2 following each other along the course of the contour K (alternately) a specific contour is projected onto the plan view P can be achieved. The contour K can be a closed contour and keep the two workpieces W1 and W2 connected to one another all around, whereby because of the first and the second side alternating sections of the weld seam (first and second area as alternating on the respectively associated first and second side alternate) the Welded connection can be more robust and stable, which can prevent or at least reduce the risk of tension, bending and cracking. The 2 shows a first area B1 with the first weld seam SN1 on the first side A, directly along the contour K, followed by a second area B2 with the second weld seam on the second side B, directly along the contour K, followed by a further first area B1 with the first weld seam on the first side A and again directly along the contour K, followed by another second area B2 with the second weld seam on the second side B. A closed contour K then results in plan view P.

3 shows a block diagram of method steps of the method for producing a weld seam on a weld object according to an embodiment of the present invention.

In the method, a welding device according to the invention is provided S1; providing S2 a welding object; holding S3 the welding object in a welding position by the holding device; generating S4 and aligning a welding beam onto an area of the welding object to be welded, wherein in the welding position a laser beam is projected through the laser device and/or an electron beam through the electron beam device as a welding beam onto the welding object from a first side and/or from a second side onto the welding object is aligned; and generating S5 a weld seam on the object to be welded.

Although the present invention has been fully described above with reference to the preferred exemplary embodiment, it is not restricted thereto but can be modified in a variety of ways.

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• EP 2919942 B1 [0005]

Claims (12)

Welding device (10) comprising: - at least one laser device (1) and/or an electron beam device (2) with which a welding beam can be generated and can be aligned to a region of a welding object (VO) to be welded and by which a weld seam can be produced on the welding object; - a holding device (3) with which the object to be welded (VO) can be held in a welding position, wherein in the welding position a laser beam is directed through the laser device (1) and/or an electron beam through the electron beam device (2) as a welding beam onto the object to be welded (VO ) can be aligned to the object to be welded (VO) from a first side and/or from a second side. Welding device (10) after claim 1 , in which the holding device (3) is designed to hold such a welding object (VO) which comprises a first workpiece (W1) and a second workpiece (W2) and these two workpieces can be connected to one another by the weld seam, the first The workpiece (W1) and the second workpiece (W2) overlap at least in some areas in the area of the weld seam. Welding device (10) after claim 2 , in which the holding device (3) comprises a first holding area (3a) and a second holding area (3b), wherein the first holding area (3a) can be attached to a first side (A) of the object to be welded (VO) and the second holding area (3b ) can be attached to a second side (B) of the object to be welded (VO). Welding device (10) after claim 3 , in which the first workpiece (W1) corresponds to the first side (A) of the object to be welded (VO) and the second workpiece (W2) corresponds to the second side (B) of the object to be welded (VO) and the holding device (3) is set up for this and such positioned to press the first workpiece (W1) toward the second workpiece (W2) with the first holding portion (3a) and to press the second workpiece (W2) toward the first workpiece (W1) with the second holding portion (3b). Welding device (10) according to one of claims 3 or 4 , in which the first holding area (3a) comprises a first cutout (A1) through which the welding beam can be applied to the first side (A) of the object to be welded (VO) and the second holding area (3b) comprises a second cutout (A2), through which the welding beam can be applied to the second side (B) of the object to be welded (VO). Welding device (10) after claim 5 , in which the first recess (A1) and the second recess (A2) along a projection direction (P) perpendicular to the first side (A) and to the second side (B) represent a partially continuous course of the weld seam or a closed weld seam contour (K). . Processing device comprising: - At least one laser device (1) and/or an electron beam device (2) with which a processing beam can be generated and can be aligned to a region of a processing object to be processed; - a holding device (3) with which the processing object can be held in a processing position, wherein in the processing position a laser beam through the laser device (1) and/or an electron beam through the electron beam device (2) onto the processing object from a first side and/or can be aligned to the processing object from a second side. A method for producing a weld seam on an object to be welded (VO), comprising the steps of: - providing (S1) a welding device (10) according to one of Claims 1 until 6 ; - Providing (S2) a welding object (VO); - Holding (S3) of the welding object (VO) in a welding position by the holding device (3); - Generating (S4) and aligning a welding beam onto an area of the welding object (VO) to be welded, wherein in the welding position a laser beam is projected through the laser device (1) and/or an electron beam through the electron beam device (2) as a welding beam onto the welding object (VO ) is aligned from a first side and/or from a second side onto the object to be welded (VO); and - producing (S5) a weld seam on the object to be welded (VO). procedure after claim 8 , in which such a welding object (VO) is held, which comprises a first workpiece (W1) and at least one second workpiece (W2) and these workpieces are connected to one another by the weld seam, the first workpiece (W1) and the at least one second Overlap the workpiece (W2) at least in some areas in the area of the weld seam. procedure after claim 8 or 9 , in which the first holding area (3a) is attached to a first side (A) of the welding object (VO) and the second holding area (3b) is attached to a second side (B) of the welding object (VO) and the first workpiece (W1 ) corresponds to the first side (A) of the welding object (VO). and the second workpiece (W2) corresponds to the second side (B) of the welding object (VO) and with the first holding area (3a) the first workpiece (W1) is pressed toward the second workpiece (W2) and with the second holding area (3b) the second workpiece (W2) is pressed towards the first workpiece (W1). procedure after claim 10 , in which the welding beam is applied to the first side (A) of the object to be welded (VO) through a first recess (A1) in the first holding area (3a) and the welding beam is applied to the second side (B) of the object to be welded (VO), the first cutout (A1) and the second cutout (A2) being viewed from a projection direction (P) perpendicular to the first side (A) and the second side (B). represent a partially continuous weld seam or a closed weld seam contour (K) and in this projection a partially continuous weld seam or a closed weld seam contour (K) is generated. procedure after claim 11 , in which, with an assumed welding position, a first weld seam is produced on the first side (A) in one or more first regions (B1) and a second weld seam is produced on the second side (B) in one or more second regions (B2). , wherein in plan view from the projection direction, the first and second areas alternately adjoin one another and a closed weld seam contour (K) is produced.

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