Battery carrier for electric drive vehicle and method for manufacturing such battery carrier

Abstract

The invention relates to a battery carrier, which is designed to be fixed in the floor area of ​​a support structure of an electrically driven motor vehicle, wherein the battery carrier (B) defines a receiving space (AR) for at least one battery element to be positioned therein by a floor section (9) and a side wall (12) surrounding the floor section (9), and wherein the side wall (12) comprises at least two side wall sections (13, 14, 20-25) which are oriented at an angle (β) greater than 0° relative to the floor section (9) and meet each other in a corner region (11a-11d). According to the invention, in such a battery carrier (B), the floor section (9) is formed in one piece from a first aluminum material, and at least the side wall sections (20-23, 24, 25) of the side wall (12) which meet each other in each of the corner regions (11a-11d), together with the corresponding corner region (11a-11d), are formed in one piece from a second aluminum material, the second aluminum material having a higher elongation at break A than the first aluminum material. The present invention also relates to a method for producing a battery support (B) of the type according to the invention.

Description

Technical Field

[0001] The invention relates to a battery carrier which is provided for fastening in the floor region of a supporting structure of an electrically driven motor vehicle, wherein the battery carrier defines a receiving space for a battery element to be positioned there with a floor section and side wall sections surrounding the floor section.

[0002] The invention also relates to a method for producing such a battery carrier. Background Art

[0003] A battery carrier of the type described here, also known in technical terms as a "battery tray," houses a reservoir in which the electrical energy required to propel the motor vehicle is stored. These typically rechargeable energy stores are commonly referred to as "batteries" or "accumulators" in common language. Therefore, for simplicity, the term "battery" will be consistently used in this document to designate the energy stores involved. Batteries of this type typically consist of a plurality of single-cell battery elements.

[0004] Unlike batteries used in motor vehicles with internal combustion engines, which typically operate at 12V or 24V, batteries that store the electrical energy used to power electric vehicles have high voltages, typically in the range of 300-1000V. The current state of the art is lithium-ion batteries, which offer high energy density and a relatively long service life. However, these batteries are sensitive to mechanical and thermal stresses. Damage to battery components can cause fires and lead to the release of toxic substances. If these toxic substances are released into the open environment in an uncontrolled manner, they can pose a significant risk. For example, if the highly reactive lithium metal in a lithium-ion battery comes into contact with water, the water molecules decompose into their constituent hydrogen and oxygen gases, which form a highly explosive gas mixture.

[0005] For these reasons, battery carriers of the type discussed here must be designed in such a way that the battery elements arranged in the battery carrier are protected from mechanical damage not only during normal driving operation but also in the event of an accident, and that components of the battery elements are also reliably prevented from entering the surroundings in the event of a leak.

[0006] EP 2 468 609 A2 describes an example of a battery carrier that should meet these requirements. The support structure for an electric vehicle proposed therein comprises a bottom part having a rectangular frame constructed in the manner of a conductor and extending in the longitudinal direction of the support structure. Plate-shaped batteries can be placed in each of the frame compartments. The frame has a coupling section on each of its narrow sides, via which the battery housing is connected to other components of the support structure, such as profiles for connection to an axle assembly or the vehicle's outer skin. In order to protect the battery from damage caused by stone impacts, etc., the frame is covered on its underside with a plate. Similarly, a cover is placed on the frame to protect the vehicle occupants from steam escaping from the battery, etc. in the event of a battery failure.

[0007] The design of a battery carrier for electric vehicles described in DE 10 2019 101 637 A1 enables simplified manufacturing compared to the prior art. The battery carrier, which has the generic features of the invention, defines a storage space in the form of a basin with its base and surrounding side walls, in which the battery components are arranged for use. At least one section of the basin, and preferably the entire basin, is manufactured as a folded component, in one piece and from a uniform material, from a sheet metal blank. At the same time, at least one groove formed across the width or length is formed in the base of the basin, so that the groove serves as a profiled crossbeam or longitudinal beam and as a reinforcement or connection surface for mounting the battery components. To produce a battery carrier designed in this manner, a flat, appropriately shaped sheet metal blank is provided. In the region of the groove to be produced, a notch is cut into the section that will later form the side wall section of the battery carrier. The blank prepared in this manner is then shaped along the predetermined edge lines of the battery carrier by various folding operations, so that the groove is formed in the base and the side wall section protrudes perpendicularly from the base. At the joints, two side wall sections or a side wall section and an end of one of the grooves meet each other, and these joints are finally joined together, wherein the connection between the joined parts is preferably implemented as a material-fit connection, in particular as welding. Summary of the Invention

[0008] Against the background of the above-mentioned prior art, the object of the present invention is to provide a cell carrier which meets the most stringent requirements with regard to gas and liquid sealing and protection of the cell from mechanical damage and which can be manufactured simply.

[0009] A method for producing such a battery carrier is also to be specified.

[0010] The invention achieves this object by a battery carrier having at least the features specified in claim 1 .

[0011] The invention also achieves this object by a method as claimed in claim 8 .

[0012] Advantageous embodiments of the invention are specified in the dependent claims and are explained in detail below as a general inventive concept.

[0013] Thus, a battery carrier according to the present invention, which is intended for attachment to a floor region of a support structure of an electrically driven motor vehicle, defines a receiving space for at least one battery element to be positioned therein by means of a floor section and side walls surrounding the floor section. The side walls comprise at least two side wall sections, which are oriented at an angle of greater than 0° relative to the floor section and meet each other in a corner region.

[0014] According to the present invention, in such a cell carrier, the base section of the cell carrier is formed integrally from a first aluminum material. Simultaneously, at least the side wall sections of the side walls that meet in one of the corner regions, along with the corresponding corner regions, are formed integrally from a second aluminum material having a higher elongation at break A than the first aluminum material.

[0015] Typically, the first aluminum material used for the bottom section according to the present invention has a tensile strength Rm of at least 170 MPa (Rm ≥ 170 MPa), for example, a tensile strength Rm of at least 220 MPa (Rm ≥ 220 MPa), in particular, a tensile strength Rm of at least 240 MPa (Rm ≥ 240 MPa), and an elongation at break A of at most 10% (A ≤ 10%), in particular, an elongation at break A of at most 8% (A ≤ 8%). Aluminum materials with this range of properties are referred to in the art and herein as "high-strength aluminum materials."

[0016] In contrast, the second aluminum material formed in one piece, including the sidewall sections that meet in the corner region and the corner region itself, typically has an elongation at break A of at least 10% (A ≥ 10), in particular at least 15% (A ≥ 15%). Aluminum materials with such high elongation at break A are referred to in the technical terminology and herein as "ductile aluminum materials."

[0017] In this sense, the base section of the battery carrier according to the invention is therefore made of high-strength aluminum, while the side wall sections that meet each other at least in the corner region and the associated corner regions formed integrally with the side wall sections are made of ductile aluminum.

[0018] Therefore, the battery carrier according to the present invention is characterized in that it is made entirely of aluminum material, which makes it significantly lighter than conventional sheet steel structures.

[0019] The present invention is based on the consideration that a high-strength aluminum material is used for the bottom section, which bears the greatest loads during use due to stone impacts and the like and must also support the weight of the battery elements. This aluminum material can reliably withstand the mechanical loads acting upon it. In contrast, additional complexly formed or technically difficult to produce shape elements are relocated to the side wall sections of the battery carrier, which are made of an aluminum material with higher ductility and correspondingly optimized deformability than the bottom section material. This makes it possible to form the battery carrier according to the present invention in one piece from a suitably shaped sheet metal blank by deformation, even though the bottom section, made of high-strength aluminum, may not be sufficiently deformable for complex shaping.

[0020] A particular advantage of this approach is that, in order to produce the cell carrier, it is no longer necessary to preform specific sections of the cell carrier separately from one another in separate working steps and then subsequently join them together, in particular weld or adhesively bond them. Instead, a sheet metal blank can be used to produce the cell carrier according to the invention, whose sections composed of different aluminum materials are connected to one another using proven joining techniques, in particular welding or adhesive bonding techniques, so that a firm and tight bond between these sections is ensured even after the sheet metal blank has been formed into the cell carrier.

[0021] In this regard, the present invention utilizes a proven principle for manufacturing components based on the use of so-called tailor-welded blanks, which is subject to locally varying requirements (see, for example, DE 10 2011 101 586 B4). The present invention not only succeeds in providing a lightweight battery carrier that reliably meets the requirements imposed on its load capacity, but also consistently ensures the tightness of the connections between the individual sections in the battery carrier according to the invention. This is achieved in particular by the fact that the corner regions of the battery carrier, which are particularly critical with regard to shaping and crack formation, are located only in the side wall sections, which are made of a ductile, well-deformable aluminum material. In this way, despite the inevitable deformations and the resulting stresses in the battery carrier during use, a permanent, tight shielding of the battery elements arranged in the battery carrier from the surroundings is ensured.

[0022] In accordance with the above explanations, in a method according to the invention for producing a battery carrier, which is provided for fastening in the floor region of a support structure of an electrically driven motor vehicle, wherein the battery carrier having a floor section and side walls surrounding the floor section define a receiving space for a battery element to be positioned there, and wherein the side walls comprise at least two side wall sections which are oriented at an angle β greater than 0° relative to the floor section and meet one another in a corner region, the method comprises the following working steps:

[0023] a) providing a sheet metal blank comprising a central section composed of a first aluminum material and at least two side sections, which are joined with their respective edges to mutually opposite edges of the central section and are composed at least partially of a second aluminum material, wherein the elongation at break A of the first aluminum material is less than the elongation at break A of the second aluminum material;

[0024] b) deforming the sheet metal blank into a cell carrier while forming a base section of the cell carrier and side walls surrounding the base section, wherein during the deformation process, a corner region in which two side wall sections meet each other is formed solely from the section of the sheet metal blank consisting of the second aluminum material;

[0025] c) optionally cutting the edge region of the surrounding side wall;

[0026] d) optionally additionally deforming the side wall or bottom section to form at least one additional shape element;

[0027] e) Optionally introducing an opening into the cell carrier.

[0028] The central base section of the battery carrier according to the invention, which is made of a relatively high-strength aluminum material, is, for example, substantially flat, so that it deforms only slightly during shaping of the battery carrier. Of course, the base section can optionally be provided with grooves and similar shape elements that can be formed despite the limited deformability of the relatively high-strength material forming the base section. Such shape elements can, for example, improve the form rigidity of the base section or facilitate the fixing and orientation of the battery elements to be arranged in the battery carrier.

[0029] Likewise, the central section of the sheet metal blank can be designed so that it forms not only the base section of the cell carrier according to the invention, but also at least one side wall section, which should, for example, have particular strength. This applies particularly when the relevant wall sections have a simple shape, i.e., for example, only straight, parallel side walls or edges. They should transition optimally into the respective adjacent side wall sections or base sections with such large bending radii that crack formation is reliably avoided. The appropriate geometry for this purpose can be determined in a known manner based on the strength and ductility properties of the aluminum material used for the base section.

[0030] Accordingly, an embodiment of the present invention which rationally and optimally utilizes the potential of two aluminum materials processed according to the present invention and having different strengths and ductility provides that the battery carrier has side wall sections of higher strength on two opposite sides, the side wall sections being formed integrally with the bottom section from the higher strength aluminum material of the bottom section, wherein one of the ductile side wall sections having a corner region of the battery carrier between them forms an extension of the corresponding higher strength side wall section, which extension can in particular extend along the bottom section.

[0031] Therefore, the bottom section of the battery carrier according to the present invention can have, for example, a rectangular basic shape when viewed in a top view, wherein higher-strength side wall sections extend on mutually opposite longitudinal sides of the bottom section, wherein the higher-strength side sections are respectively extended on their sides corresponding to the corner regions of the battery carrier by ductile side wall sections connected thereto, in particular welded thereto.

[0032] In an embodiment of the invention, the side wall of the battery carrier has at least one side wall section which is made integrally with the bottom section from a higher-strength aluminum material. In this embodiment, the corner region which is critical with regard to deformation properties, in particular the risk of crack formation, is shifted in this way to the battery carrier section made of a well-deformable ductile aluminum material or to the sheet metal blank used to produce it.

[0033] To join the bottom section made of a first, higher-strength aluminum material to the side wall section made of a second, more ductile aluminum material, all joining methods known from practice for this purpose can be used. These include, in particular, welding methods such as laser welding or friction stir welding, but also adhesive bonding methods or other known methods by which the sections to be joined, made of different materials, can be permanently sealed and fixedly connected to one another by a material fit, a force fit, and / or a positive fit.

[0034] In the implementation of a sheet metal blank for forming a battery carrier according to the above description, the central section of the sheet metal blank provided in working step a) of the method according to the invention extends over the entire width of the sheet metal blank, but only over a portion of its length, wherein, during the deformation process in working step b) of the method according to the invention, the edge sections of the central section, which are opposite to each other and extend between the ductile side sections of the sheet metal blank, are each deformed into higher-strength side wall sections of the battery carrier.

[0035] In particular, all known deep-drawing methods that have proven reliable for forming tailor-welded blanks are suitable for forming the blanks configured according to the invention into the battery housing according to the invention, as are also used, for example, in the prior art disclosed in the aforementioned DE 10 2011 101 586 B4.

[0036] If mechanical properties of aluminum materials are specified in this document, such as the tensile strength Rm or the elongation at break A, these are determined in accordance with DIN EN ISO 6892-1:2020-06 and DIN 50125:2016-12, respectively.

[0037] The angle β enclosed between the base section and the surrounding side walls of the cell carrier according to the invention is in each case greater than 0°, meaning that the base section and the surrounding side wall section extend in planes oriented at an angle to one another. Typically, the angle β is in the range of 80° to 135°, in particular 85° to 120°, with an angle β of ≥ 90° being particularly practical from a manufacturing perspective. It goes without saying that the angle β described here should not be understood in a strictly mathematical sense, but rather in a technical sense, i.e., it should be designed with tolerances that are unavoidable in manufacturing and generally permissible in practice.

[0038] As the first aluminum material of higher strength for the bottom section, for example all aluminum alloys that are classified in the 6000 series, 7000 series or 8000 series aluminum materials according to the nomenclature developed by the Aluminum Association are suitable. 6000 series materials have proven to be particularly suitable. These include, for example, the materials EN AW-6101, EN AW-6101A, EN AW-6101B, ENAW-6201, EN AW-6401, EN AW-6003, EN AW-6005, EN AW-6005A, EN AW-6005B, EN AW-6106, EN AW-6008, EN AW-6110A, EN AW-6011, EN AW-6012, EN AW-6012A, EN AW-6013, EN AW-6014EN, AW-6015, EN AW-6016, EN AW-6018, EN AW-6023, EN AW-6025, EN AW-6026, EN AW6050, EN AW-6351, EN AW-6351A,EN AW-6951, EN AW-6056, EN AW-6060, EN AW-6360, ENAW-6061A, EN AW-6261, EN AW-6262, EN AW-6262A, EN AW-6063, EN AW-6063A, EN AW-6463, EN AW-6064A, EN AW-6065, EN AW-6081, AW-6181, EN AW-6082, EN AW-6182, EN AW-6082A.

[0039] According to the invention, the alloy meets the requirements for a high-strength aluminum material for the base section, namely, a tensile strength Rm of at least 170 MPa (Rm ≥ 170 MPa), in particular at least 220 MPa (Rm ≥ 220 MPa), and an elongation at break A of less than 10% (A ≤ 10%), in particular less than 9% (A < 10%), for example, at most 8% (A ≤ 8%) or at most 7% (A ≤ 7%). High-strength aluminum materials with a tensile strength Rm of at least 240 MPa, in particular at least 250 MPa, have proven particularly effective.

[0040] In general, as the tensile strength Rm increases, the elongation at break A and the resulting deformability decrease. Therefore, the aluminum material preferably used according to the invention for the base section typically only has an elongation at break A of up to 7% (A≤7%) at a tensile strength Rm of at least 250 MPa. The high-strength aluminum material with a tensile strength of up to 250 MPa (Rm≥250 MPa) and an elongation at break A of up to 7% (A≤7%) specified for the higher-strength base section of the battery carrier according to the invention has proven particularly suitable for the purposes of the invention in view of the demands placed on its strength and ductility. Examples of aluminum materials that meet the requirements set forth according to the invention for the material of the central base section are, for example, those materials designated EN AW-6003, EN AW-6005, EN AW-6005A, EN AW-6005B, EN AW-6060, EN AW-6061A, EN AW-6063, and EN AW-6063A.

[0041] In contrast, for the side wall sections and side wall corner regions of the cell carrier according to the invention, which are composed of a second ductile aluminum material, materials are used that have an elongation at break A of at least 10% (A ≥ 10%), in particular at least 15% (A ≥ 15%), and preferably at least 20% (A ≥ 20%). The tensile strength Rm of these materials is typically at most 240 MPa (Rm ≤ 240 MPa), in particular at most 230 MPa (Rm ≤ 230 MPa), with a tensile strength of 180 MPa to 240 MPa (180 MPa ≤ Rm ≤ 240 MPa), in particular at most 230 MPa (Rm ≤ 230 MPa, in particular 180 MPa ≤ Rm ≤ 230 MPa), and an elongation at break A of 13% to 28% (13% ≤ A ≤ 28%) being particularly suitable for practical applications.

[0042] Based on the nomenclature of the 3,000, 4,000 or 5,000 series of ductile iron materials required to be submitted at the side wall section of the original wafer. In a special place, there are 5000 series of materials that can be confirmed. Series comprehensive materials EN AW-5005, EN AW-5005A, EN AW-5305, EN AW-5505, EN AW-5605, EN AW-5006, ENAW-5010, EN AW-5110, EN AW-5210, EN AW-5310, EN AW-5018, EN AW-5018B, EN AW-5019, ENAW-5119, EN AW-5119A, EN AW-5026, EN AW-5040, EN AW-5042, EN AW-5049, EN AW-5149, ENAW-5249, EN AW-5449, EN AW-5449A, EN AW-5050, EN AW-5050A, EN AW-5051A, EN AW-5251, EN AW-5052, EN AW-5252, EN AW-5352, EN AW-5154A, EN AW-5154B, EN AW-5354, EN AW-5454, EN AW-5554, EN AW-5654, EN AW-5654A, EN AW-5754, EN AW-5356, EN AW-5356A, ENAW-5456, EN AW-5456A, EN AW-5456B, EN AW-5556A, EN AW-5556B, EN AW-5657, EN AW-5058, EN AW-5059, EN AW-5070, EN AW-5082, EN AW-5182, EN AW-5083, EN AW-5183, EN AW-5183, EN AW-5283A, EN AW-5383, EN AW-5086, EN AW-5186, EN AW-5087, EN AW-5187, ENAW-5088. Among them, for example, the material EN AW-5005, EN AW-5005A, EN AW-5083, ENAW-5654A, EN AW-5754 may be used for specific purposes.

[0043] The sidewall sections made of ductile aluminum material are also each shaped so that the areas critical for deformation and crack formation are remote from the less deformable base section. To this end, the ductile sidewall sections can have a first sidewall region on the bottom side that connects to the respective edge of the base section as a lateral extension and transitions only at a certain distance from the less deformable base section into a corner region, through which the sidewall region oriented at a greater angle to the base section connects to the base section. This design is particularly suitable for ductile sidewall sections that extend along a joint, through which the corresponding section of the battery carrier according to the present invention made of ductile material is connected to the section of the battery carrier made of a higher-strength material. This design of the ductile sidewall sections allows loads that may occur during shaping of the battery housing or during use to be remote from the joint connection. This also helps to minimize the risk of crack formation in the relevant joint connection area.

[0044] After the sheet blank obtained according to the invention has been deformed in the method according to the invention (working steps a) and b), the resulting battery carrier component can undergo further deformation steps in a manner known per se, in order to form further shape elements, for example, on the side walls or base sections. These shape elements can be, for example, flanges that can be used to fasten the battery carrier to the vehicle body, grooves or other structures for reinforcing the corresponding side wall sections, or depressions, projections, etc. that can be used to fasten, retain, or position the battery elements to be arranged in the battery carrier.

[0045] Likewise optionally, the cell carrier obtained after the forming process can be trimmed in the edge region of the surrounding side walls in a manner also known per se in order to remove excess sheet metal.

[0046] Finally, if necessary, openings can also be optionally formed, in particular punched or drilled, in the battery carrier, which are required for fastening the battery carrier to the vehicle body or for auxiliary devices for fastening battery elements in the battery carrier. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The present invention will be further described below with the aid of the accompanying drawings showing exemplary embodiments.

[0048] Intentionally showing:

[0049] Figure 1 : Top view of the blank used to manufacture the battery carrier:

[0050] Figure 1a : The parts are shown in a top view, and the parts are assembled according to Figure 1 of slab;

[0051] Figure 2 :Through deep drawing operation Figure 1 A top view of a blank formed from a slab;

[0052] Figure 3 : A top view shows the blank after trimming;

[0053] Figure 4 : shows the blank after further deformation in a top view;

[0054] Figure 5 : A top view of the manufactured battery carrier is shown;

[0055] Figure 6 : A perspective view of the finished battery carrier on its underside. DETAILED DESCRIPTION

[0056] exist Figure 1 The sheet metal blank 1 shown in FIG. 1 for producing a cell carrier B consists of a central section 2 and two side sections 3 and 4. The central section 2, which is rectangular in plan view, extends over the entire width W of the sheet metal blank 1 and occupies the majority of its length L, here approximately five-sevenths. Each of the identically shaped side sections 3 and 4 is connected, in particular welded, with its corresponding edge to one of the edges 5 and 6 of the central section 2, which are oriented transversely to the longitudinal extension of the sheet metal blank 1.

[0057] The side sections 3, 4 can be connected to the central section 2 using various joining methods that have proven effective in the prior art for producing permanently sealed and durable joints. These include, in particular, laser welding or friction stir welding methods commonly used in the production of tailor-welded blanks from aluminum sheet metal. To produce the connection, the side sections 3, 4 are preferably oriented at an obtuse angle to the edges 5, 6 of the central section 2 in order to achieve joints S1, S2 that are as flat as possible.

[0058] exist Figure 1 In FIG, the outer edge course of a circumferential edge section 8 of a cell carrier B to be produced from the sheet metal blank 1 is indicated by a dot-dash line.

[0059] The central section 2 and side sections 3 and 4 are each cut from 3 mm thick sheet metal. The central section is made of the relatively strong aluminum material AA6063 in the T6 temper, while the two ductile side sections 3 and 4 are made of the relatively ductile aluminum material AA5754 in the O temper. In the T6 temper, the AA6063 aluminum material has a tensile strength Rm of 260 MPa and an elongation at break A of 7%. In contrast, the AA5754 aluminum material in the O temper has a tensile strength Rm of 230 MPa and an elongation at break A of 22%.

[0060] exist Figure 1 In FIG, a central base section 9 of the cell carrier B to be produced is additionally enclosed by a dashed line.

[0061] Dotted line in Figure 1 3 shows a depression 10 formed into the bottom section 9 of the cell carrier B to be produced.

[0062] This means that the planar extensions of the side sections 3, 4 and the central section 2 in the sheet metal blank 1 are selected such that the corner regions 11a-11d of the side walls 12 of the cell carrier B to be produced, which are critical in terms of deformation properties, surrounding the central base section 9, are formed in the ductile side sections 3, 4. In contrast, the side wall sections 13, 14 of the cell carrier B to be produced, which extend linearly and parallel to one another along the longitudinal sides L1, L2 of the cell carrier B and are therefore easily formable, are formed for the majority of their length from the higher-strength aluminum material of the central section 2 of the sheet metal blank 1.

[0063] To be formed into a cell carrier B, the sheet metal blank 1 is placed in a conventional press (not shown here), the shape of the male and female dies of which corresponds to the desired shape of the cell carrier B. The press forms a blank R from the sheet metal blank 1, the basic shape of which already largely corresponds to the shape of the finished cell carrier B ( Figure 2 ).

[0064] The blank R therefore already has a central bottom section 9 formed from the central section 2 of the sheet metal blank 1 and having a recess 10 formed therein, side walls 12 surrounding the bottom section 9 and an edge section 8 surrounding the cell carrier B, which protrudes laterally from the side walls 12 in the manner of a flange.

[0065] In a subsequent working step, the edge section 8 is formed along the dashed line ( Figure 1 、 Figure 2 ) is cut to remove the excess plate section ( Figure 3 ).

[0066] Subsequently, the blank R undergoes a further deformation in which the regions of the edge section 8 extending parallel to the edges 5, 6 or seams S1, S2 are provided with depressions 16, 17 ( Figure 4 ).

[0067] Finally, through-holes 18 arranged at regular intervals are introduced into the recesses 16, 17 of the edge section 8, for example by a punching operation, which can be used to later fasten the finished battery carrier B to a vehicle body (not shown here) or preferably to fasten a cover (also not shown here) to the battery carrier B ( Figure 5 ).

[0068] The obtained Figure 6 The cell carrier B, which is shown "inverted", ie from the perspective of its underside 19, thus has a central base section 9. A depression 10 is formed into the base section 9, which extends over almost the entire surface of the base section 9, except for the edge surrounding it.

[0069] The side walls 12 extend around the base section 9. The side walls 12 are arranged at an angle relative to the base section 9 such that an angle β of approximately 90° is enclosed between the side walls 12 and the base section 9. The side walls 12 include side wall sections 13, 14 made of the higher-strength aluminum material of the base section 9, which extend along the longitudinal sides L1, L2 of the cell carrier B and are formed integrally with the central base section 9, which is formed from the central section 2 of the sheet metal blank 1. The higher-strength side wall sections 13, 14 of the side walls 12 are extended at their ends corresponding to the corner regions 11a-11d of the cell carrier B by short side wall sections 20, 21, 22, 23, each formed from the side sections 3, 4 of the sheet metal blank 1. The short, ductile side wall sections 20-23 meet in their respective corresponding corner regions 11a-11d respectively with another ductile side wall section 24, 25 of the side wall 12, said side wall sections being likewise formed by one of the ductile side sections 3, 4 and extending parallel to the seams S1, S2 along the respective lateral sides Q1, Q2 of the cell carrier B.

[0070] Therefore, in the battery carrier B, all problematic areas with respect to the risk of deformation and crack formation, in particular the corner areas 11a-11d, are arranged in sections made of ductile aluminum material, while the central bottom section 9 and the side wall sections 13, 14 corresponding to the longitudinal sides L1, L2 are made of higher-strength aluminum material, and the side wall sections 13, 14 bear the main load of the battery elements to be accommodated by the battery carrier B with the bottom section 9.

[0071] Here, the joints S1 and S2 are also protected from damage by load during the forming of the cell carrier B by shifting the region critical for deformation away from the joints into the ductile section of the cell carrier B. To this end, the side wall sections 24 and 25 made of ductile aluminum material are formed such that they comprise a first side wall region 26 on the bottom side, a second side wall region 27 oriented at an angle relative to the first side wall region 26 and the bottom section 9 , and a transition region 28 , wherein the first side wall region 26 joins the outer edge region of the bottom section 9 at its edge region corresponding to the bottom section 9 and forms a lateral extension of the bottom section 9 , and the first side wall region 26 transitions into the second side wall region 27 via the transition region 28 .

[0072] The design and construction of the battery carrier B according to the invention ensures permanent, sealed shielding and also secure, stable holding of battery elements (not shown here) which are arranged for use in the receiving space AR defined by the battery carrier B.

[0073] Description of Reference Numerals

[0074] 1 slab

[0075] 2 Central section of slab 1

[0076] 3, 4 Side sections of slab 1

[0077] 5, 6 Edges of central segment 2

[0078] 8 Edge section of battery carrier B

[0079] 9 Central bottom section of battery carrier B

[0080] 10 Recess formed into the bottom section

[0081] 11a-11d Corner area of ​​the side wall

[0082] 12 Sidewall

[0083] 13, 14 Higher strength sidewall sections

[0084] 16, 17 Recesses (shape elements) of edge section 8

[0085] 18 through holes

[0086] 19 Underside of battery carrier B

[0087] 20-23 Short ductile sidewall segments

[0088] 24, 25 Ductile sidewall sections

[0089] 26 First side wall region on the bottom side of the ductile side wall sections 24, 25

[0090] 27 Second side wall region of the ductile side wall sections 24, 25

[0091] 28 Transition zone between ductile side wall sections 24 and 25

[0092] β is the angle between the side wall 12 and the bottom section 9

[0093] AR Accommodation Space

[0094] B Battery carrier

[0095] L Length of slab 1

[0096] L1, L2 Longitudinal sides of battery carrier B

[0097] Q1, Q2 lateral side of battery carrier B

[0098] R blank

[0099] S1, S2 seams

[0100] W is the width of slab 1

Claims

1. A battery carrier, which is provided for fastening in the bottom region of a support structure of an electrically driven motor vehicle, wherein: The battery carrier (B) defines a receiving space (AR) for at least one battery element to be positioned therein by means of a base section (9) and a side wall (12) surrounding the base section (9), wherein the side wall (12) comprises at least two side wall sections (13, 14, 20-25) which are oriented at an angle (β) greater than 0° relative to the base section (9) and meet each other in a corner region (11a-11d). It is characterized in that The bottom section (9) of the battery carrier (B) is formed in one piece from a first aluminum material, and At least the side wall sections (20-23, 24, 25) of the side wall (12) which meet each other in one of the corner regions (11a-11d), together with the corresponding corner region (11a-11d), are formed in one piece from a second aluminum material having a higher elongation at break A than the first aluminum material.

2. The battery carrier according to claim 1, characterized in that The first aluminum material has a tensile strength Rm of at least 170 MPa and an elongation at break A of less than 10%.

3. The battery carrier according to claim 1, characterized in that The second aluminum material has an elongation at break A of at least 10%.

4. The battery carrier according to any one of claims 1 to 3, characterized in that The battery carrier (B) has side wall sections (13, 14) on two opposite sides (L1, L2), which are formed integrally with the bottom section (9) from a first aluminum material, and each of the side wall sections (20-23) with a corner region (11a-11d) of the battery carrier (B) between them forms an extension of one of the side wall sections (20-23) made of a second aluminum material of the bottom section (9).

5. The battery carrier according to claim 4, characterized in that The bottom section (9) has a rectangular basic shape when viewed from above, and side wall sections (13, 14) made of the first aluminum material extend on mutually opposite longitudinal sides (L1, L2) of the bottom section (9), and the side wall sections (13, 14) made of the first aluminum material are respectively extended on their sides corresponding to the corner areas (11a-11d) of the battery carrier (B) by side wall sections made of the second aluminum material connected thereto.

6. The battery carrier according to claim 5, characterized in that The higher strength side wall sections (13, 14) extend parallel to each other.

7. The battery carrier according to any one of claims 1 to 3, characterized in that: The first aluminum material is a 6000, 7000, or 8000 series aluminum alloy and the second aluminum material is a 3000, 4000, or 5000 series aluminum alloy.

8. A method for producing a battery carrier (B) which is provided for fastening in the floor region of a support structure of an electrically driven motor vehicle, wherein: The battery carrier (B) defines a receiving space (AR) for a battery element to be positioned therein by means of a bottom section (9) and a side wall (12) surrounding the bottom section (9), wherein the side wall (12) comprises at least two side wall sections (13, 14, 20-23, 24, 25) which are oriented at an angle β greater than 0° relative to the bottom section (9) and meet each other in a corner region (11a-11d). The method comprises the following working steps: a) providing a plate blank (1), comprising a central section (2) made of a first aluminum material and at least two side sections (3, 4), the side sections being joined with their respective edges to mutually opposite edges (5, 6) of the central section (2) and being at least partially made of a second aluminum material, wherein the elongation at break A of the first aluminum material is less than the elongation at break A of the second aluminum material; b) deforming the sheet metal blank (1) into a cell carrier (B) while forming a bottom section (9) of the cell carrier (B) and a side wall (12) surrounding the bottom section (9), wherein during the deformation process, two side wall sections (20-23, 24, 25) of the side wall (12) meet each other in corner regions (11a-11d), which are formed exclusively by sections (3, 4) of the sheet metal blank (1) made of the second aluminum material; c) optionally trimming the edge region (8) of the surrounding side wall (12); d) optionally additionally deforming the side wall (12) or the bottom section (9) to form at least one additional shape element (16, 17); e) Optionally, an opening ( 18 ) is introduced into the cell carrier (B).

9. The method according to claim 8, characterized in that The central section (2) of the sheet metal blank (1) provided in the working step a) extends over the entire width (W) of the sheet metal blank (1), but only over a part of the length (L) of the sheet metal blank (1), and during the deformation in the working step b), the edge sections of the central section (2) that are opposite to each other and extend between the ductile side sections (3, 4) of the sheet metal blank (1) are deformed into a respective higher-strength side wall section (13, 14) of the battery carrier (B).

10. The method according to claim 9, characterized in that Side wall sections (13, 14) made of a first aluminum material extend parallel to each other.

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