Method for forming a sealed enveloping body for a high-voltage battery storage device, high-voltage battery storage device and use of a laser hybrid welding device

Abstract

Method for forming a sealed enveloping body for a high-voltage battery storage device from a first and a second joining partner (1, 2) by joining the first and the second joining partner (1, 2) made of an aluminum alloy by welding by means of an arc which is ignited in a welding phase between a welding wire electrode (130) and a welding point (31) to produce a weld seam (30), wherein a second joining partner (2) is provided which has a thickness (d2) of at least 3 mm before the welding phase, wherein during the welding phase, heat is introduced into the joining partners (1, 2) to be welded by means of a laser beam (110) generated by a laser beam source and directed onto the first joining partner (1), wherein welding is carried out through a first joining partner (1) into a second joining partner (2), wherein the second joining partner (2) has a greater thickness (d2) than the first joining partner (1).

Description

[0001] The invention relates to a method for forming a sealed enveloping body for a high-voltage battery storage device from a first and a second joining partner made of an aluminum alloy. The invention also relates to a high-voltage battery storage device comprising two joining partners made of a respective aluminum alloy, and to the use of a laser hybrid welding device for welding joining partners made of a respective aluminum alloy to form a sealed enveloping body for a high-voltage battery storage device. background

[0002] US 2003 / 0 136 768 A1 relates to YAG laser welding, wherein the supplied welding heat is assisted by an arc, or a welding method using a combination of a YAG laser and an arc, and a device therefor.

[0003] JP 2005 - 262 257 A relates to a welding method for joining lap joints in structures formed from thin metal plates.

[0004] DE 102 94 581 B4 relates to a welding process using a high energy density beam and an arc discharge.

[0005] CN 1 08 767 338 A relates to a method for repairing welds between a battery casing and a top cover.

[0006] JP 2003 - 88 969 A concerns the welding of thick plates with a laser, whereby the penetration shape is changed by the pressure of the gas blown onto the welding point.

[0007] DE 603 ​​12 323 T2 concerns the application of a hybrid welding process that combines a laser beam with an arc for multi-thickness welding.

[0008] To join metal components together, a laser hybrid welding process can be used, for example. US 7,154,065 B2, DE 10 2020 210 988 A1 and DE 10 2020 212 859 A1 describe laser hybrid welding processes in which sheet-like components, for example made of an aluminum alloy, can be joined along a fillet, flange, or butt weld. In these processes, a joining gap is provided between the joining partners during the welding phase. When joining aluminum components, such joining gaps are considered essential to dissipate vapor phases and thus counteract hot cracks or pore formation. For precise seam production, it is common practice to prepare the joining partners through washing processes. Forming the joining gap requires complex fixation of the joining partners.

[0009] Friction stir welding (FSW) is generally used to join metal components lying on top of one another without a joint gap, for example thick sheets made of aluminum or aluminum alloys. For example, friction stir welding along linear weld seams or friction stir spot welding is often used to join thick sheet-like components, particularly those made of aluminum alloy, in an overlap joint. Unlike friction stir spot welding, linear friction stir welding is particularly preferred when a sealing joint between two components is to be achieved to form a casing. In friction stir welding, friction energy is used through the relative movement of a wear-resistant rotating tool relative to the multiple components to be joined. The tool is essentially rotationally symmetrical and comprises a central pin and a shoulder coaxially surrounding the pin.For joining, the rotating tool is pressed into the joining partners with high force. The tool is held for some time with the pin in a plunge point and brought with the shoulder against a contact surface of the joining partners. The friction between the tool and the contact surface heats the joining partners. In the area of ​​the shoulder, a temperature rise often occurs to just below the melting point of the joining partners, which plasticizes the material and can achieve mixing of the joining zone. The tool can be guided along a seam with a feed movement. The movement of the tool in the joining partners causes the plasticized material of the joining partners to be transported and mixed, forming a weld seam.Finally, the rotating tool is withdrawn from the seam area, usually leaving a characteristic seam end point with a so-called end hole corresponding to the projection in the joined product. Friction stir welding is particularly popular for joining aluminum sheets because hot cracks or pore formation, which can occur when welding aluminum with other methods, can be avoided by avoiding a liquid or vapor phase. However, joining thick sheets using friction stir welding requires very high process forces of often several kN, which necessitates complex fixation of the joining partners. The high joining forces often result in component deformation. To produce seams precisely, it is common practice to prepare the joining partners through washing processes.In some applications, such as the manufacture of enclosures for high-voltage battery packs in electric vehicles, the end holes represent critical weak points or unwanted leaks. There is also an increased risk of leaks in the area of ​​directional changes in linear welds. Due to the required contact of the tool shoulder with the contact area, friction stir welding is not suitable for some geometries, especially three-dimensional ones. Furthermore, no transition between fillet, butt, and lap welds can be achieved. Due to the special characteristics of friction stir welding, specially trained personnel are required. Summary

[0010] The object of the invention is to overcome the disadvantages of the prior art and, in particular, to provide a method for joining joining partners made of an aluminum alloy, which does not require any complex preparation and fixing and / or is suitable, in particular, for joining thick sheet-like components to one another while forming a reliable and tight connection.

[0011] To achieve the object, a method is provided for joining a first and a second joining partner made of an aluminum alloy by welding using an arc. In particular, the first joining partner can comprise the same or a different aluminum alloy as the second joining partner or can consist of the same or a different aluminum alloy. The arc is ignited in a welding phase between a welding wire electrode and a welding point to produce a weld seam. During the welding phase, heat is introduced into the joining partners to be welded by means of a laser beam generated by a laser beam source and directed onto the first joining partner. According to the invention, welding takes place through a first joining partner into a second joining partner. During the welding phase, the laser beam can penetrate through the first joining partner into the second joining partner.In particular, the heat introduced by the laser beam during the welding phase can weaken or destroy an oxide layer on the front side of the first joining partner, on the back side of the first joining partner, and / or on the front side of the second joining partner in the contact area adjacent to the first joining partner in the region of the weld. It should be understood that the first and second joining partners each have a front side and a back side, wherein in particular the front side and the back side form opposing surfaces of the respective, preferably sheet-like, joining partner.

[0012] According to a preferred embodiment of the invention, during the welding phase, the second joining partner can be in flat, gap-free contact with a rear side of the first joining partner opposite the laser beam source and welding wire electrode. The contact section can preferably be realized by a lap joint or parallel joint of the joining partners. The laser beam is thus directed onto the front side of the first joining partner, while the second joining partner is in flat contact with the rear side of the first joining partner in the contact section. Preferably, the front side of the second joining partner is in flat, gap-free contact with the rear side of the first joining partner, at least in some sections.

[0013] It may be preferred that at least the first joining partner is sheet-like. Particularly preferably, both the first and second joining partners are sheet-like. Sheet-like joining partners have a three-dimensional shape whose thickness is significantly less than their width and length. For example, a sheet-like joining partner can be provided with a width and / or length that is at least 10 times, in particular at least 100 times, preferably at least 500 times, greater than the thickness of the sheet-like joining partner.

[0014] According to one embodiment of the method, a first joining partner is provided which, in particular in the contact section, has a thickness of at least 1.5 mm, in particular at least 2 mm, and / or not more than 10 mm, in particular not more than 7 mm, before the welding phase.

[0015] According to the invention, a second joining partner is provided which, in particular in the contact section, has a thickness of at least 3 mm before the welding phase. In addition, the second joining partner, in particular in the contact section, can have a thickness of no more than 20 mm, in particular no more than 12 mm, before the welding phase. The second joining partner has a greater thickness in the contact section, in particular generally, than the first joining partner in the contact section or in general. Preferably, the first joining partner is designed, in particular, like a sheet metal piece with a constant thickness over the entire extension of the first joining partner in its length and / or width. Preferably, the second joining partner is designed, in particular, like a sheet metal piece with a constant thickness over the entire extension of the second joining partner in its length and / or width.

[0016] In a preferred embodiment of the method, the first joining partner is provided with an aluminum alloy selected from the group comprising EN AW5xxx and AW6xxx, comprising or with the exception of unavoidable impurities and / or an oxide layer consisting thereof. It is preferred that at least the first joining partner comprises or consists of a wrought aluminum alloy or AW aluminum alloy (wrought aluminum). Additionally or alternatively, the second joining partner is provided with an aluminum alloy selected from the group comprising EN AW5xxx and AW6xxx, comprising or with the exception of unavoidable impurities and / or an oxide layer consisting thereof. It may be preferred that the first joining partner and / or the second joining partner comprises or consists of a wrought aluminum alloy or AW aluminum alloy (wrought aluminum), for example EN AW 5754 (EN AW AlMg3).In particular, it can be provided that the first joining partner and / or the second joining partner is free of an aluminum cast alloy or AC aluminum alloy (aluminum cast), for example free of EN AC-51200 (EN AC AlMg9). Alternatively, only the first joining partner can be free of an aluminum cast alloy or AC aluminum alloy, wherein it is conceivable that the second joining partner comprises a wrought aluminum alloy and / or a cast aluminum alloy. The wrought aluminum alloy can be non-hardenable or hardenable. Preferably, the wrought aluminum alloy comprises, in particular exclusively, one or more alloy constituents selected from the group comprising magnesium, manganese, zinc, and silicon. The EN AW5xxx and / or EN AW5xxx aluminum alloys can be formulated according to ISO 209-1 (in particular ISO 209-1:1989) and / or EN 573 (in particular EN 573-3:2022-09). The aluminum casting alloy can be non-heat-treatable or heat-treatable.The aluminum casting alloy preferably comprises, in particular exclusively, one or more alloying constituents selected from the group comprising tin, magnesium, silicon, copper, titanium, and nickel. The first and second joining partners may comprise the same aluminum alloy or, with the exception of unavoidable impurities and / or an oxide layer, consist of the same aluminum alloy. It may be preferred for the first joining partner to consist of a different aluminum alloy than the second joining partner.

[0017] According to another embodiment of the method, which can be combined with the previous ones, the welding wire electrode is directed during the welding phase onto a wire projection point, in particular onto a tool center point located in the direction of an extension of the laser beam. A wire focus distance of at least 1 mm, in particular at least 1.5 mm, and no more than 2.5 mm, in particular no more than 2 mm, is set between the wire projection point and the laser beam. The wire projection point can be defined by the projection of the welding wire electrode in the direction of its alignment with the first joining partner. The wire focus distance can be determined on the surface (front side) of the first joining partner between the center line or focus point line of the laser beam emitted by the laser beam source and the wire projection point.The actual focal point of the laser beam can be located between the front and back of the first joining partner. The welding wire electrode is preferably pin-shaped, in particular rectilinear, and is aligned according to its longitudinal axis. Preferably, a first distance, in particular a substantially constant one, between the laser source and the first joining partner is maintained continuously during the welding phase. Preferably, a second distance, in particular a substantially constant one, between the welding wire electrode and the first joining partner and / or the wire projection point is maintained continuously during the welding phase.

[0018] In a preferred embodiment of the method, the weld point is moved at a welding speed during the welding phase. In particular, during the movement (movement along a preferably rectilinear welding path) of the weld point, the laser beam is held in advance of the welding wire electrode. Preferably, the joining partners are welded together at a welding speed of at least 30 mm / s, in particular at least 35 mm / s, and / or a welding speed of no more than 100 mm / s, in particular no more than 50 mm / s. The method according to the invention can therefore be significantly faster than a comparable friction stir welding process. In particular, the laser beam and the welding beam electrode are arranged in the same imaginary plane as the welding path along which the weld point is moved during the welding phase.Relative to the surface of the first joining partner, an imaginary perpendicular can be aligned at the welding point relative to the direction of movement of the welding point. The laser beam is preferably held substantially in line with the vertical with respect to the direction of movement, preferably equal to the vertical, in particular in front of the vertical or behind the vertical. Alternatively or additionally, the wire projection point and / or the welding wire electrode are held behind the vertical with respect to the direction of movement. The vertical can extend through the focal point of the laser beam. Relative to the preferably flat front side of the first joining partner in the region of the welding point, the laser beam can be aligned at an inclination angle and / or the welding wire electrode at an alignment angle during the welding phase. The inclination angle is preferably greater (more obtuse) than the (more acute) alignment angle.In particular, the laser beam can be aligned during the welding phase at an inclination angle of at least 60°, in particular at least 70°, preferably at least 80°, and / or not more than 120°, in particular not more than 110°, preferably not more than 100°. Preferably, the inclination angle differs from 90°, in particular by at least 1°, preferably at least 2° or at least 3°, particularly preferably at least 5°. Additionally or alternatively, the welding wire electrode can be aligned during the welding phase at an orientation angle of at least 20°, in particular at least 30°, and / or not more than 60°, in particular not more than 50°.

[0019] In a preferred development of the method, the laser beam source is operated during the welding phase with a laser power of at least 2 kW, in particular at least 3 kW, and / or not more than 10 kW, in particular not more than 6 kW.

[0020] Additionally or alternatively, in a further development of the method, the welding wire electrode can be operated during the welding phase at a wire speed of at least 2 mm / s, in particular at least 4 mm / s, and / or not more than 15 mm / s, in particular not more than 7.5 mm / s. The welding wire electrode can be matched to a guide and / or gas nozzle, from which a shielding gas and / or an inert gas can be or will be released during the welding phase, in such a way that one end of the welding wire electrode protrudes from the guide and / or the gases at a predetermined distance. The predetermined distance can be at least 10 mm, preferably at least 12 mm, particularly preferably at least 14 mm, and / or not more than 20 mm, preferably not more than 16 mm, particularly preferably not more than 15 mm.Surprisingly, it has been shown that particularly good deep penetration welding results can be achieved through a first joining partner into a second joining partner, especially for distances in the range of 10 mm to 20 mm.

[0021] Preferably, the method described above can be carried out to form a sealed enveloping body, in particular for a high-voltage battery storage device, which comprises the first and the second joining partner or from the first and the second joining partner.

[0022] In the method, at least one other welding phase can be performed before and / or after the welding phase, in particular using the same laser hybrid welding device, wherein two, in particular at least the first joining partner and / or the second joining partner and optionally at least one other joining partner, are joined together according to a fillet, overlap, or corner weld. Alternatively or additionally, at least one other welding phase can be performed before and / or after the welding phase to produce a butt weld, in particular at an I-joint or a Y-joint, in particular using the same laser hybrid welding device.

[0023] The invention also relates to a high-voltage battery storage device comprising a sealed enveloping body (component) that comprises two joining partners made of an aluminum alloy that are in contact with one another at least in sections. In the high-voltage battery storage device according to the invention, a weld seam protrudes through a first joining partner into a second joining partner. The first joining partner can be arranged relative to the second joining partner, in particular according to an overlap joint or a parallel joint. In the high-voltage battery storage device, the first and second joining partners can each have a front side and a back side, wherein in particular the front side and the back side form mutually opposite surfaces of the respective, preferably sheet-like, joining partner.In the high-voltage battery according to the invention, the front side of the second joining partner rests at least partially (or over the entire surface) gap-free and flat against the back side of the first joining partner. The first joining partner and / or the second joining partner can, for example, be sheet-like. According to one embodiment of the method, the first joining partner has a thickness of at least 1.5 mm, in particular at least 2 mm, and / or no more than 10 mm, in particular no more than 7 mm, in the contact section before the welding phase.

[0024] The second joining partner has a thickness of at least 3 mm in the contact section before the welding phase. Optionally, the second joining partner has a thickness of no more than 20 mm, in particular no more than 12 mm, in the contact section before the welding phase. The first and / or the second joining partner comprise or consist of a respective, in particular the same or different, aluminum alloy selected from the group comprising EN AW5xxx and AW6xxx.

[0025] The invention also relates to the use of a laser hybrid welding device for welding joining partners made of an aluminum alloy to form a weld seam extending through a first joining partner into a second joining partner. The weld seam can be formed in a contact section where the joining partners lie flat against one another, at least in sections, without a gap. It is conceivable that additional sections between the joining partners are welded together using the laser hybrid welding device, in which an (air) gap is present between the first and the second joining partner, in particular an air gap with a gap width of no more than 5 mm, in particular no more than 3 mm, preferably no more than 1 mm (in the direction of the laser beam and / or the vertical).It should be understood that, when using the laser hybrid welding device, the weld seam is preferably formed such that the gap-free contact section is larger than one or more adjacent sections with a gap. Thus, when using the laser hybrid welding device according to the invention, even joining partners with deformed or defective front and / or back sides can be joined within a relatively large tolerance range.

[0026] The use of a laser hybrid welding system is advantageous for welding long seams with short welding times. The beginning and end of the seam can be optimally designed using a laser hybrid welding system, and in particular, penetration depth and the beginnings of welds with a sealing function can be reliably displayed.

[0027] The laser hybrid welding device can be used to form a component in the form of a sealed enveloping body for a high-voltage battery storage device, as described above. The component described above can be manufactured using the laser hybrid welding device. The method for joining joining partners can be used to manufacture the component described above. The component can be formed by the method for joining joining partners described above.

[0028] With the method according to the invention and / or with the inventive use of a laser hybrid welding device, a significant speed advantage can be achieved compared to producing a weld seam of the same size using friction stir welding. Complex seam preparation of the joining partners is eliminated. The very complex preparation required for friction stir welding, particularly fixation, can also be eliminated. By deep-welding the joining partners using the laser beam, comparatively low consumption of filler material and shielding gas can be achieved. By performing production steps that are often performed by dedicated friction stir welding systems in a laser hybrid welding system configured according to the invention, which has numerous other possible applications, the additional investment in a friction stir welding system can be avoided in many cases.Compared to friction stir welding systems, the use of a laser hybrid welding system requires significantly less training effort to qualify the responsible personnel. Description of implementation examples

[0029] Further embodiments are explained in more detail below with reference to the figures of a drawing. Here: Fig. 1 a schematic representation of a welding process; and Fig. 2 a micrograph of a component.

[0030] In the following description of preferred embodiments, the same or similar reference numerals are used for the same and similar components.

[0031] Fig.Figure 1 shows a schematic representation of the process in which a first joining partner 1 and a second joining partner 2, both formed from a respective aluminum alloy, are welded by means of an arc and a laser beam 110 and thereby joined to form a component 3. A laser hybrid welding device (not shown in detail) can be used to carry out the process.

[0032] Fig. Figure 2 shows a cross-sectional micrograph of the welding area 31, wherein a first joining partner 1 is welded to a second joining partner 2 to form an integral component 3. The joining partners 1, 2 are joined together using a laser hybrid weld seam 30.

[0033] The laser hybrid welding device can be guided along a welding path in a welding direction V, for example, using robotics. The welding path can be straight, for example. If component 3 forms a casing that is intended to be highly impermeable, it is important that the laser hybrid weld seam 30 is tight. Therefore, the laser hybrid weld seam 30 must not contain an unacceptable number of pores or cavities.

[0034] The joining partners 1, 2 have a respective thickness d1, d2, which extends in the vertical direction Z. The joining partners 1 and 2 extend in a longitudinal direction X and a transverse direction Y. The welding direction V can, for example, be oriented in the longitudinal direction X. It should be understood that weld seams other than purely straight weld seams can also be formed using the welding method according to the invention. For example, using a laser hybrid welding device, weld seams with at least partially or completely curved, for example, circular, welding paths can also be formed.

[0035] At the Fig.1, the first joining partner 1 is a sheet metal having a first thickness d1. The first thickness d1 can, for example, be in the range of 2 mm to 7 mm. The second sheet metal-like joining partner 2 has a second thickness d2. The second thickness d2 is greater than the first thickness d1. The second thickness d2 is at least 3 mm. As shown in Fig. As shown in Figure 1, the second joining partner 2 can also be a sheet metal part. The second sheet metal joining partner can, for example, have a thickness d2 of no more than 12 mm.

[0036] During the welding phase, the first joining partner 1 is arranged between the laser hybrid welding device and the second joining partner 2. The first joining partner 1 can be made, for example, from an aluminum alloy of the EN AW5xxx group, and the second joining partner 2 from an aluminum alloy of the EN AW6xxx group. The two joining partners 1, 2 can be arranged, for example, in a parallel joint or a lap joint. The rear side 19 of the first joining partner 1 rests flatly and gap-free against the front side 21 of the second joining partner 2, at least in sections.

[0037] The joining partners 1 and 2, formed from an aluminum alloy, have an oxide layer on their surfaces, i.e., on their respective front sides 11, 21 and on their respective back sides 19, 29. To achieve a clean, material-tight weld, the use of the laser hybrid welding device first weakens or even completely destroys the oxide layers in the contact section where the back side 19 of the first joining partner 1 rests flatly and gap-free against the front side 21 of the second joining partner 2. For this purpose, the laser beam introduces heat into the joining partners 1, 2 to be welded. The two joining partners 1 and 2 are then welded using an arc ignited between the welding point 31 and a welding wire electrode 130 of the laser hybrid welding device. The welding point 31 can also be referred to as a focal spot.Preferably, the interface of the laser beam 110 and the extension of the welding wire electrode in the weld point forms the tool center point. The laser hybrid weld seam 30, which connects the joining partners 1 and 2, extends completely through the first joining partner 1 and into the second joining partner 2.

[0038] During a welding phase, the laser hybrid welding device can be aligned according to a perpendicular S to the front side 11 of the first or upper joining partner 1. During the welding phase, the laser beam 110 moves along the laser hybrid welding direction V in front of the wire projection point p, which is located at one of its rectilinear extensions of the welding wire electrode 130 on the front side 11 of the first joining partner 1 in the region of the welding point 31. When using the laser hybrid welding device, the welding wire electrode 130 is guided at a certain distance, preferably parallel to the front side 11 of the first joining partner 1. The welding wire electrode 130 can protrude from a guide and / or shielding gas nozzle 132 of the laser hybrid welding device by a certain amount, for example, 15 mm (stickout t).The welding wire electrode 130 can be conveyed out of the laser hybrid welding device during the welding phase with a particularly continuous and / or constant feed rate of at least 2 mm / min, in particular at least 4 mm / min, and / or not more than 10 mm / min, in particular not more than 7.5 mm / min.

[0039] During the welding phase, the laser beam 110 continuously moves in front of the wire projection point p. During the welding phase, a preferably constant wire focus distance a can be maintained between the wire projection point p and the laser beam 110. For example, at a welding speed between 35 mm / s and 50 mm / s and a laser power between 3 kW and 6 kW, a wire focus distance a can be set between 1.5 mm and 2 mm.

[0040] The laser beam 110 can be directed at an inclination angle α between 80° and 100° with respect to the front side 11 of the first joining partner 1 in the region of the weld point 31. The inclination angle α is preferably different from 90°, i.e., perpendicular S. The welding wire electrode 130 is preferably directed at the weld point 31 at an orientation angle β that is smaller than the inclination angle α of the laser beam 110. For example, the orientation angle β can be between 30° and 50°.

[0041] Using the welding process according to the invention, it was possible, for example, to achieve through-welded joints with good properties using the following process parameters: test A B C D E F G First joining partner AL5754(4.85mm) AL5754(4.89mm) AL6061 (4.78 mm) AL5754(5 mm) A L6061(2.5 mm) AL5754(4.98mm) Second joining partner AC AlSi 9(3.00mm) AC AlSi 8.7(3.15mm) AC Al Si 9 (2.91 mm) AC Al Si 7(5 mm) AC Al Si9(5 mm) AC Al Si 7 (5.07 mm) Welding speed 50 mm / s 50 mm / s 50 mm / s 50 mm / s 50 mm / s 50 mm / s Wire feed speed 5.0 m / min 5.5 m / min 5.0 m / min 4.5 m / min 5.0 m / min 4.5 m / min Laser power 5.5 kW 5.5 kW 5.5 kW 5.0 kW 5.5 kW 5.0 kW Gap width 0.23 mm 0.09 mm 0.15 mm 1 mm 0.2 mm 0.1mm 0.2mm Burn-in depth 2.19 mm 1.02 mm 1.52 mm 1.5 mm 2.5 mm 1.35mm 2.15mm Seam width 2.68 mm 2.45 mm 2.54 mm 2 mm 2 mm 2.18mm 2.65mm

[0042] The welding speed refers to the feed rate V. Using the above-mentioned process parameters, the listed results regarding penetration depth (vertical depth of the weld seam in the second joining partner), weld width (horizontal width of the weld seam on the upper side of the second joining partner), and gap width (distance between the underside of the first joining partner and the upper side of the second joining partner) were achieved. In examples D, F, and G, AC Al Si 7 T6 gravity die casting was used for the second joining partner without machining directly on the casting skin.

[0043] The features disclosed in the above description, the claims and the drawings may be important for the realization of the various embodiments both individually and in any combination. List of reference symbols: 1 first joining partner 2 second joining partner 3 Component 11 first front page 19 first back 21 second front page 29 second back 30 laser hybrid weld seams 31 welding point 110 laser beam 130 welding wire electrode a Wire focus distance d1 Thickness of the first joining partner d2 Thickness of the second joining partner S Vertical p Wire projection point t Stickout V Welding direction X Longitudinal direction Y transverse direction Z vertical direction α angle of inclination β orientation angle

Claims

[1] Method for forming a sealed enveloping body for a high-voltage battery storage device from a first and a second joining partner (1, 2) by joining the first and the second joining partner (1, 2) made of an aluminum alloy by welding by means of an arc which is ignited in a welding phase between a welding wire electrode (130) and a welding point (31) to produce a weld seam (30), wherein a second joining partner (2) is provided which has a thickness (d2) of at least 3 mm before the welding phase, wherein during the welding phase, heat is introduced into the joining partners (1, 2) to be welded by means of a laser beam (110) generated by a laser beam source and directed onto the first joining partner (1), wherein welding is carried out through a first joining partner (1) into a second joining partner (2), wherein the second joining partner (2) has a greater thickness (d2) than the first Joining partner (1). [2] Method according to claim 1, characterized by that during the welding phase, the second joining partner (2) lies flat in a contact section on a rear side (19) of the first joining partner (1) opposite the laser beam source and welding wire electrode (130) without a gap. [3] Method according to claim 1 or 2, characterized by that the first joining partner (1) in the contact section before the welding phase has a thickness (d1) of at least 1.5 mm, in particular at least 2 mm, and / or not more than 10 mm, in particular not more than 7 mm, and that the second joining partner (2) in the contact section before the welding phase has a thickness (d2) of at least 3 mm and / or not more than 20 mm, in particular not more than 12 mm. [4] Method according to one of the preceding claims, characterized bythat the first joining partner (1) and / or the second joining partner (2) is provided with an aluminum alloy selected from the group comprising EN AW5xxx and AW6xxx or consisting thereof. [5] Method according to claim 4, characterized by that the second joining partner (2) comprises a different aluminum alloy than the first joining partner (1). [6] Method according to claim 4 or 5, characterized by that the first joining partner (1) is free of an aluminum casting alloy or AC aluminum alloy. [7] Method according to one of the preceding claims, characterized by that the welding wire electrode (130) is directed towards a wire projection point (p), in particular a tool centre point, during the welding phase and a wire focus distance (a) of at least 1 mm, in particular at least 1.5 mm, and not more than 2.5 mm, in particular not more than 2 mm, is set between the wire projection point (p) and the laser beam (110). [8] Method according to one of the preceding claims, characterized by that during the welding phase the welding point (31) is moved at a welding speed, in particular wherein the laser beam (110) is held in advance of the welding wire electrode (130), wherein preferably the joining partners (1, 2) are welded to one another at a welding speed of at least 30 mm / s, in particular at least 35 mm / s, and / or a welding speed of not more than 100 mm / s, in particular not more than 50 mm / s. [9] High-voltage battery storage device, comprising a sealed enveloping body which comprises two joining partners (1, 2) made of an aluminium alloy which at least partially lie flat against one another, wherein a laser hybrid weld seam (30) projects through a first joining partner (1) into a second joining partner (2), wherein the second joining partner (2) has a thickness (d2) of at least 3 mm, and wherein the second joining partner (2) has a greater thickness (d2) than the first joining partner (1). [10] Use of a laser hybrid welding device for welding joining partners (1, 2) made of an aluminum alloy to form a sealed enveloping body for a high-voltage battery storage device from a first and a second joining partner (1, 2) to form a weld seam (30) projecting through a first joining partner (1) into a second joining partner (2), wherein a second joining partner (2) is provided which has a thickness (d2) of at least 3 mm before the welding phase, and wherein the second joining partner (2) has a greater thickness (d2) than the first joining partner (1).

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