Battery tray for battery bracket of electric vehicle

Abstract

The invention relates to a battery tray (1) for an electric vehicle battery carrier, in which the battery tray (1) has a bottom (3) and a circumferential wall which extends integrally from the bottom (3) and is made of the same material, and optionally an outer circumferential flange (6) which protrudes from the wall, according to the invention, the battery tray (1) is made of a hardenable steel slab (13) as a hot-formed and press-hardened component, the tensile strength Rm of which is greater than or equal to 1250 MPa and the respective tensile strength Rm is less than 1100 MPa in the respective corner regions (10) of the side walls (4, 5).

Description

Technical Field

[0001] This invention relates to a battery tray for electric vehicle battery holders. Background Technology

[0002] Electric vehicles are known in the prior art. In this context, a motor vehicle, also called an electric vehicle, is a car powered by an electric motor. The required energy is stored in a corresponding battery storage device. This battery storage device is also called a battery tray or battery holder. They have a battery tray that can be closed with a cover. The drive battery or battery is then placed inside a cylindrical housing. This battery tray is typically located under the floor of the electric vehicle.

[0003] Battery trays are typically made of metal, particularly steel or aluminum. The batteries within the tray should be protected from environmental factors, especially weather conditions and moisture. Furthermore, the interior of the battery tray should be liquid-sealed, especially in the event of an impact, to prevent any liquids, particularly coolant or fluids from the battery, from leaking into the environment.

[0004] These battery trays are typically made of metal, particularly steel, but aluminum is also used. Especially with steel, the battery tray is referred to as a formed component. For this purpose, forming processes, particularly deep drawing, are employed to shape the battery tray.

[0005] It is also known that battery trays such as thermoformed and compressive-hardened components can be produced. Thermoforming and compressive-hardening techniques can achieve tensile strengths (Rm) exceeding 1000 MPa. Summary of the Invention

[0006] The object of the present invention is to provide a battery tray for a battery holder, which is manufactured by molding but optimized in terms of its geometry, particularly for the capacity of the batteries arranged inside.

[0007] According to the present invention, the aforementioned objective is achieved by a battery tray for a battery holder used in electric vehicles.

[0008] The method for achieving the objective is realized through the features of the method according to claim 11.

[0009] Battery trays for electric vehicle battery holders have a bottom. The bottom is generally flat. However, the bottom may have optional reinforcing structures to provide, for example, reinforcement, chassis protection, and / or bottom cooling.

[0010] The circumferential wall is integrally formed with the bottom and made of the same material. Therefore, the circumferential wall has two external sidewalls relative to the lateral direction of the vehicle. The circumferential wall also has a front wall located at the front and a rear wall located at the rear along the longitudinal direction of the vehicle. From a top view, the area of ​​the battery tray exceeds 2m².2 The height of the sidewall is preferably greater than 10cm, especially greater than 12cm, particularly preferably greater than 15cm, and most preferably greater than 18cm.

[0011] Optionally, a flange projecting outward from the circumferential wall is also formed. The flange is preferably circumferentially designed. The flange can be designed as a support surface, and also as the contact surface and sealing surface of the cover. The cover can be flat. The cover can also be installed according to the principle of a protective cover.

[0012] The battery tray is also made from a single steel slab. This slab is specifically made from a hardenable steel alloy. For example, boron-manganese steel, such as 22MnB5, can be used. The battery tray is also manufactured using thermoforming and compressive hardening processes, resulting in a tensile strength Rm ≥ 1250 MPa.

[0013] According to the present invention, the battery tray is characterized in that the tensile strength Rm in the corresponding corner regions of the sidewalls is less than 1000 MPa. The corner regions are the areas where the respective sidewalls are located. Relative to the lateral direction of the vehicle, for example, the outer sidewall forms a corner with the rear wall or the front wall. These corner regions are also made of the same material in a single piece, as the entire battery tray is manufactured using a corresponding forming process, particularly a deep drawing process. Since a lower strength material structure is formed in the corner regions, the forming process can be optimized. Targeted material flow from the bottom, from the remaining areas of the walls or sidewalls, and / or from the flanges, is achieved, preventing cracking or excessive thinning in the corner regions. Therefore, the forming of the corner regions can be more optimized and sharper. In particular, the battery tray according to the present invention is produced by the following method, thereby also achieving the aforementioned product characteristics.

[0014] According to the invention, the corner region is located between two adjacent sidewalls. However, the corner region may also include at least a portion of the transition portion from the bottom of the corresponding corner region of the sidewall, wherein the transition portion is formed as a deep-drawing radius.

[0015] According to the present invention, the tensile strength of each corner of the square battery tray in the top view is designed to be Rm<1000MPa.

[0016] Particularly preferably, in the sense of the invention, the corner region is formed to be flexible, wherein the two sidewalls are arranged at an angle of 80° to 110° to each other, and particularly at an angle of 90° to 110°, and very particularly preferably at an angle of 90° to 100°.

[0017] If the battery tray has more than four corners, for example, it is hexagonal in top view, and the corners or corner areas are greater than 90°, such as two 90° corner areas, then according to the invention, these 90° corner areas between the two sidewalls in top view have a tensile strength Rm < 1000 MPa. If four additional approximately 135° corner areas are formed, these 135° corner areas in top view can be completely hardened.

[0018] For a battery tray with a rectangular top view and therefore four corner regions, each corner region is preferably formed as flexible, as described above. In a polygonal battery tray, at least two corner regions may be flexible.

[0019] If a flange is provided, the corner region of the flange can also be made of a relatively soft material with a tensile strength Rm less than 1100 MPa. However, according to the present invention, the outer flange region in the corner region also preferably has relatively high strength, with a tensile strength Rm greater than 1250 MPa. This achieves optimal results, particularly in terms of collision safety and reinforcement of the battery tray.

[0020] Particularly preferably, the relatively soft tensile strength in the corner region is designed to be between 550 and 800 MPa, particularly achieved through a targeted hybrid or intermediate-stage structure. In the corner region, this is a hybrid structure of bainite and / or ferrite and / or pearlite, with a corresponding proportion of martensite, and, where necessary, retained austenite.

[0021] In the remaining areas of the battery tray, particularly the bottom, sidewalls, and flanges, an essentially martensitic structure is formed. Its tensile strength Rm is greater than 1250 MPa, particularly greater than 1350 MPa, and especially preferably greater than 1500 MPa.

[0022] This is a significant advantage of the present invention. Because the tensile strength Rm of the entire battery tray area is very high, thin-walled materials can be used. This achieves high strength characteristics, thus high stiffness, and also provides high impact safety and high support capacity for batteries weighing hundreds of kilograms housed within. Due to the small wall thickness, particularly less than 5 mm, especially preferably less than 3 mm, and particularly between 1 mm and 2 mm, the battery tray has a low self-weight.

[0023] Within the scope of this invention, the battery tray can be used to insert or place a drive battery. The battery tray can also be stacked on top of the battery as a cover to form a closed battery holder together with a base plate or another battery tray.

[0024] By means of a further means according to the invention, particularly in the production process, especially in deep drawing methods with soft corner regions, a smaller wall thickness can be used in the starting material of the slab, since it can be expected that only a smaller thinning stretch and / or a smaller crack will form. Thus, the wall thickness can be minimized through the ingenious design of the corner regions.

[0025] Furthermore, the tensile strength Rm at the transition from the bottom to the sidewall is set to be greater than 1250 MPa. These transitions extend for at least 70% of the length of the corresponding sidewall. In particular, this results in a high level of crash safety, especially in the event of a side impact, but also in the event of a frontal impact, because the transitions, which are crucial for the aforementioned crash scenarios, have a correspondingly high tensile strength, which in turn provides sufficient inherent stiffness for the battery tray.

[0026] Particularly preferably, the hollow profile can also be attached to the outer sidewall and / or flange, such as an L-shaped hollow profile or a cap-shaped profile. This cap-shaped profile can be externally attached to the sidewall, for example, through a joining process, particularly by spot welding. Any possible softening is negligible here. The hollow profile or the corresponding side reinforcement is not itself a vehicle sill or longitudinal support of the vehicle guide frame. The hollow profile is an integral part of the battery tray itself. This not only provides improved side impact protection but also provides the possibility of vehicle body fastening, meaning the battery tray can be fastened to the vehicle body via the hollow profile. For example, the battery tray can be attached from below to the vehicle sill or longitudinal support of the vehicle guide frame, for example, by screwing it on.

[0027] Particularly preferably, the slab also includes an anti-corrosion coating, particularly, for example, an aluminum-silicon based coating.

[0028] According to another possible configuration of the invention, the sidewalls have different heights at the front and rear, as well as on their respective outer sides. The corresponding covers, which are then coupled to the battery tray, can then be adapted to the different heights of the sidewalls.

[0029] Furthermore, longitudinal and / or transverse reinforcing ribs can be integrally molded into the bottom from the same material. Corresponding cooling channel structures can also be molded or embossed into the bottom. This reinforces the bottom, thus providing chassis protection or shock protection (Bollerschutz). Alternatively, cooling channel structures or corresponding gaskets can be embossed into the bottom. They are then designed to point downwards, specifically along the vehicle's vertical direction, in the installation case. The cooling channel structure can then be formed using an additional base plate or inner plate to accordingly cool batteries arranged in battery trays or placed on the bottom.

[0030] An important aspect of this invention is that the corner regions do not shift further outward relative to the interior. Therefore, the corner regions are located behind the extensions of the sidewalls or transverse walls, respectively. In particular, in the case of reinforcing profiles arranged on the outer side, these extensions can extend into the corner regions. If the corner regions were to shift or adjust outward again, continuous connection with the longitudinal profiles would be impossible.

[0031] The present invention also includes a corresponding method for producing the above-mentioned battery tray, comprising the following steps:

[0032] Slabs made of hardenable steel alloys are provided.

[0033] The subsequent corner regions undergo partial or complete austenitization and partial intermediate cooling.

[0034] The battery tray is placed in a thermoforming and compressive hardening tool and subjected to thermoforming and compressive hardening, thereby making the tensile strength Rm of the battery tray greater than or equal to 1250 MPa, while the tensile strength of the corner region is less than 1100 MPa.

[0035] Austenitization specifically refers to heating to a temperature above Ac3, that is, depending on the hardenable steel alloy used, the temperature exceeds 900°C.

[0036] In the method according to the invention, it is conceivable to first partially austenitize the slab made of a hardenable steel alloy, thereby generating temperatures above Ac3 in the regions forming the subsequent bottom and sidewalls. However, for the purposes of this invention, it is preferred that full austenitization can also be performed, particularly in the case of coated slabs, so that the pre-coating is fully alloyed.

[0037] After complete austenitization, the subsequent corner regions undergo specialized or intermediate cooling. This can be achieved, for example, by using a nozzle to blow air. Contact cooling can also be used. An intermediate stage structure can also be formed here. Specifically, the cooling temperature is 70°C to 200°C, particularly 100°C to 150°C, compared to the Ac3 temperature, so the temperature of these regions is preferably between 600°C and 800°C. Therefore, these regions are not too soft, so a targeted material flow enters the corner regions from the warmer and therefore softer adjacent bottom, sidewall, and / or flange regions, thereby particularly avoiding severe thinning and stretching of the corner regions themselves during forming. This results in negligible thinning of the material in the corner regions to be formed. Cracking is also avoided. Therefore, the initial slab can have an optimized, particularly low, wall thickness, and no cracking or excessive thinning occurs in the corner regions during subsequent hot forming. The partially tempered steel slab is placed in a hot forming tool or partially cooled in a hot forming tool as described above. The hot forming process is then carried out, followed by quench hardening or compressive hardening, resulting in hardening and transformation into a hardened material structure. This is essentially a hard martensitic material structure derived from the previous austenitic region. In the intermediate cooling region, a mixed structure of pearlite, ferrite, and / or bainite is formed, incorporating both martensitic and retained austenitic components. Even in the finished component, the corner regions remain relatively soft. Due to the higher degree of forming in the corner regions, thinning and stretching are also performed here. Because this region is intermediate cooled, it is easier to form and has softer tensile strength in subsequent finished components, thus reliably preventing delayed fracture in further manufacturing and assembly steps, and also preventing delayed fracture in the event of a vehicle collision. Attached Figure Description

[0038] Further advantages, features, characteristics, and aspects of the invention are the subject of the following description. Preferred design variations are shown in the schematic diagrams. These contribute to a more readily understood understanding of the invention. The foregoing and following embodiments can be combined individually with each other as needed without departing from the scope of the invention. In the accompanying drawings:

[0039] Figure 1 A perspective view of a battery tray with soft corner regions manufactured according to the present invention is shown;

[0040] Figure 2 A top view of the slab and the subsequently formed battery tray is shown;

[0041] Figure 3 A top view of the slab and the subsequently formed battery tray is shown, which is an alternative design variant with a soft flange area;

[0042] Figure 4 It shows that according to Figure 2The cross-section line IV-IV passes through the cross-section of the angular region;

[0043] Figure 5 It shows along Figure 2 The cross-section of the cross-section line VV;

[0044] Figure 6 A top view of a hexagonal battery tray is shown;

[0045] Figure 7 A top view shows an alternative design for the hexagonal battery tray.

[0046] In the figure, the same reference symbols are used to represent the same or similar parts, even if repeated descriptions or representations are omitted for simplification.

[0047] List of reference numerals in the attached diagram:

[0048] 1-Tray; 2-Battery bracket; 3-Bottom; 4-Longitudinal wall; 4'-Longitudinal wall; 4”-Longitudinal wall; 5-Transverse wall; 6-Flange; 7-Cover; 8-Longitudinal support; 9-Transverse reinforcing rib; 10-Corner area; 11-Transition from 6; 12-Outer corner area; 13-Transition section; 14-Slab; 15-Rounded corner; 16-Transition area; 17-Area; 18-Transition area; 19-Longitudinal reinforcing rib; 20-Transverse reinforcing rib; L-Longitudinal direction; X-Longitudinal direction of motor vehicle; Y-Transverse direction of motor vehicle; α-Angle with vertical line; α'-Angle between side walls; β-Angle with vertical line; β'-Angle between side walls; y'-Angle between side walls. Detailed Implementation

[0049] Figure 1 The invention produces a product for use with Figure 2 The battery holder 2 shown is a deep-drawn tray 1. The battery holder 2 has a tray itself, wherein the tray 1 has a bottom 3 and walls 4, 5 extending at an angle α to the bottom 3. These walls will also be referred to below as longitudinal wall 4 and transverse wall 5. In addition, corresponding flanges 6 are arranged to project laterally from the walls. The flanges 6 can be used as drawing flanges during the deep-drawing process, and subsequently for connection with the cover 7 shown. Longitudinal supports 8 can be arranged in the tray 1 itself. The longitudinal supports 8 are particularly suitable for arranging and securing batteries (not shown in detail) in the tray 1. In addition, as Figure 1 As shown, a transverse reinforcing rib 9 can be molded in the bottom 3 of the tray 1.

[0050] According to the present invention, the corresponding corner region 10 is now defined as having lower tensile strength compared to the side walls 4, 5 formed by the corresponding longitudinal wall 4 and transverse wall 5. The outer peripheral flange 6 protrudes from the side walls, i.e., the transverse wall 5 and the longitudinal wall 4, respectively. The flange 6, longitudinal wall 4, transverse wall 5, and bottom 6 are integrally formed and made of the same material from a sheet metal. Therefore, it is a component produced by molding, rather than by further joining or other means. The soft corner region 10 is preferably, in the sense of the present invention, the connection region between the longitudinal wall 4 and the transverse wall 5, i.e., the lateral side wall, front wall, or rear wall relative to the transverse direction Y of the vehicle, i.e., the transverse wall 5 relative to the longitudinal direction X of the vehicle.

[0051] Furthermore, a transition portion 11 is formed from the corresponding sidewall 4 or 5 to the flange 6. The transition portion 11 may have a soft material structure, similar to the material structure of the flange 6. However, it may also be designed to be rigid.

[0052] A softer material structure with a tensile strength Rm less than 1100 MPa can also be formed in the region of flange 6 or in the transition corner region 12. This is the region where the corner region merges with the bottom 3. Figure 1 This is also shown again in the lower right corner of the image plane.

[0053] The corresponding transition portion 13 from the bottom 3 to the sidewall, i.e., the transverse wall 5 or the longitudinal wall 4, is preferably designed to have a high tensile strength greater than 1250 MPa. This transition portion extends in the longitudinal direction L beyond at least 70% of the longitudinal wall 4 shown herein. The transition portion 13 is preferably formed circumferentially over at least 70% of the area between the bottom 3 and the corresponding sidewalls 4, 5. Furthermore, a transition portion 11 is formed from the corresponding sidewall 4 or 5 to the flange 6. The transition portion 11 may have a flexible material structure, similar to the material structure of the flange 6.

[0054] refer to Figure 1 The illustrations are for illustrative purposes only, but for the full disclosure herein, the flexible material structure is not formed in the straight longitudinal or transverse sections of the sidewall 4 or the transverse wall 5, respectively. Specifically, less than 10%, particularly less than 5%, and preferably less than 4%, of the length extending in the longitudinal or transverse direction (i.e., the X or Y direction of the vehicle) from the corresponding angular region starting from the straight section of the sidewall 4 or the transverse wall 5 is formed of a flexible material structure. The remainder of the sidewall, i.e., the majority of the sidewall, has a rigid material structure.

[0055] Furthermore, longitudinal reinforcing ribs 19 and transverse reinforcing ribs 20 can be molded in the bottom 3. They then protrude upwards from the bottom 3 along the vertical direction of the vehicle, or downwards along the vertical direction of the vehicle.

[0056] Figure 2 a) and Figure 2b) illustrates how to pretreat the slab according to the invention in order to produce subsequent battery trays.

[0057] Figure 2 (a) shows a slab 14 for producing the battery tray 1. This slab 14 can be rounded in its subsequent outer corner regions, i.e., having rounded corners 15. In the subsequently formed corner regions 10, the slab 14 is pre-tempered, preferably at a temperature of 600°C to 750°C. This is particularly preferably achieved through intercooling from a previously existing temperature above Ac3, especially above 800°C, and most preferably above 900°C. The temperature of the remaining regions of the slab 14 is greater than 800°C, particularly greater than 900°C, thus resulting in an austenitic material structure.

[0058] according to Figure 2 (b) The battery tray 1 has been formed. Due to the deep drawing process, the external dimensions have been reduced or lowered. Subsequently, the corner regions 10 in the corresponding transitions from the transverse wall 5 to the longitudinal wall 4 are formed to be relatively soft. Through the deep drawing process, particularly according to the cup-shaped deep drawing principle, these corner regions 10 exhibit the highest degree of deformation. Due to the intermediate cooling temperature, better forming and / or corresponding material flow from adjacent or even hotter regions can be observed here. The softer tensile strength on the finished battery tray 1 then compensates for the existing thinning stretch, preventing the formation of delayed cracks. The remaining areas, including the transverse wall 5, longitudinal wall 4, transition 13, bottom 3, and outer circumferential flange 6, have a tensile strength Rm greater than 1250 MPa, thus providing sufficient inherent stiffness.

[0059] according to Figure 2 As shown in b), the outer flange 6 is also hardened, so its tensile strength Rm is greater than 1250 MPa. In addition, the outer corner region, indicated by reference numeral 12, i.e., the transition 13 from the corner region 10 to the bottom 3, also has a softer material structure.

[0060] Figure 3 a) and Figure 2 b) shows an alternative design variant. This is consistent with... Figure 2 a) and Figure 2 Similar to b), the external flange 6 is not fully hardened, but rather has a soft material structure in the corner region 10 itself.

[0061] The advantage of this invention is that, in the event of a frontal or side impact, the entire corner region 10 is easily deformed due to its low strength, but will not tear. Therefore, the impact energy can be dissipated through forming work. Furthermore, in the corner region 10, the structure or continuous wall is preserved, thus preventing leakage even in the event of a collision.

[0062] Figure 4 It shows along Figure 2A cross-sectional view along section line IV-IV. Here, a cross-sectional view is formed through corner region 10 to show that the outwardly projecting flange 6 is also formed in corner region 10, which extends substantially horizontally. Bottom 3 also extends horizontally. Corner region 10 itself is set at an angle to the vertical direction and merges with bottom 3 as part of the corresponding sidewall as an outer corner region 12. The flange 6 itself may particularly preferably be completely hardened or at least partially softened. This results in the formation of a transition zone as a tensile strength gradient in the region indicated by reference numeral 16, i.e., in the transition 11 from flange 6 to the sidewall section in corner region 10. The actual corner region 10 is then formed in region 17, which has a soft material structure. Again, transition region 18 forms bottom region, where the transition zone or tensile strength gradient is formed. Similarly, in bottom 3, the largest part has not yet undergone intermediate cooling, and therefore has a hard material structure after compressive hardening, such as Figure 4 As shown.

[0063] Figure 5 It shows along Figure 2 The cross-section of the cross-section line VV is shown. This is the corresponding cross-sectional view through the longitudinal wall 4. The cross-sectional view can also be obtained through the transverse wall 5, and is almost identical here. It can be seen that an angle β with respect to the vertical direction is formed in the corresponding longitudinal wall 4 or transverse wall 5, which is <7°, particularly <6°, and preferably <5°. The smaller the angle, the higher the space utilization inside the battery tray 1. However, the smaller the angle, the more difficult the deep drawing process becomes.

[0064] The following specific features apply to all the above embodiments and the general description of the invention. Figure 4 The angle α of the middle angle region, that is, according to Figure 2 The 45° section of the mid-section line IV-IV, and the angle β according to the section line VV (e.g. Figure 5 As shown, for example, on walls 4 and 5, compared to the angle β, it is at most 40% larger, particularly at most 30% larger, and preferably at most 25% larger. This means that angle α is greater than angle β. According to the previously mentioned angle range, angle α is at most 40% larger than angle β. In another preferred embodiment variation, according to... Figure 4 The radius generated in the area indicated by reference numeral 12 in the attached figure can be greater than Figure 5 The radius at reference numeral 13 in the attached figure is at most 30% larger, preferably at most 20% larger, and particularly at most 15% larger. The radius may also be referred to as the bottom radius.

[0065] In addition, alternative or additional land, according to Figure 4 The radius of the transition of flange 6 is proportional to... Figure 5The radius of the transition of the flange 6 is at most 30%, particularly at most 20%, and especially preferably at most 15%. The relative relationships between the aforementioned angles or corresponding transition radii can be transferred to all embodiments herein without departing from the disclosure of the invention.

[0066] Figure 6 A top view of the hexagonal battery tray is shown. Here, the two corner regions 10 form an angle α' of approximately 90°. This means that the longitudinal wall 4 extends at a 90° angle to the transverse wall 5 at the corner region 10. The longitudinal wall 4 has another longitudinal wall 4' in the front region. An angle β' is formed between the longitudinal wall 4 and the longitudinal wall 4'. In the front end region, therefore along the longitudinal direction of the vehicle x on the front transverse wall 5, the longitudinal wall 4' and the transverse wall 5 are arranged at an angle y' of approximately 135°. The angles β' and y' of 135° are then fully hardened together with the rest of the tray. According to the invention, only the corner region at α' is relatively soft, with a tensile strength RM of less than 1100 MPa.

[0067] In comparison, Figure 7 Another design variation is shown. A top view of the hexagonal tray 1 is also shown. Here, the rear corner regions 10 relative to the longitudinal direction of the vehicle are flexible between the longitudinal wall 4 and the transverse wall 5. Furthermore, an angle β' exists between the longitudinal wall 4 and the longitudinal wall 4”.

[0068] The angle β can be approximately 150° and is fully hardened with the rest of the tray 1. The front corner region 10' between the longitudinal wall 4” and the transverse wall 5 has an angle of approximately 100°. Therefore, according to the invention, these corner regions are also flexible.

Claims

1. A battery tray (1) for an electric vehicle battery holder, wherein, The battery tray (1) has a bottom (3) and a circumferential wall integrally extending from the bottom (3) and made of the same material, and an outer circumferential flange (6) optionally projecting from the wall, wherein the battery tray (1) is made of a hardenable steel sheet (13) into a thermoformed and compressively hardened component with a tensile strength Rm greater than or equal to 1250 MPa, characterized in that the tensile strength Rm is less than 1100 MPa in at least one corner region (10) of the sidewalls (4, 5).

2. The battery tray (1) according to claim 1, characterized in that, The at least one corner region (10) is formed between the bottom (3) and the two adjacent sidewalls (4, 5).

3. The battery tray (1) according to any one of claims 1 or 2, characterized in that, The tensile strength Rm in the corner region (10) is between 900MPa and 550MPa, preferably between 600MPa and 800MPa.

4. The battery tray (1) according to any one of the preceding claims, characterized in that, The flange (6) has a tensile strength greater than or equal to 1250 MPa in at least one corner region (10), and in particular, the flange (6) is circumferentially fully hardened.

5. The battery tray (1) according to any one of the preceding claims, characterized in that, A mixed structure of bainite and / or ferrite and / or pearlite, optionally having a certain proportion of martensite, is formed in at least one corner region (10).

6. The battery tray (1) according to any one of the preceding claims, characterized in that, A tensile strength Rm greater than 1250 MPa is formed in the transition portion (13) from the bottom (3) to the sidewalls (4, 5), wherein the transition portion (13) preferably extends beyond at least 70% of the length of the sidewalls (4, 5) and is shaped to a deep drawing radius.

7. The battery tray (1) according to any one of the preceding claims, characterized in that, Preferably, it is connected to the outside of the sidewalls (4, 5) and / or the flange (6) as a side reinforcement of a sheet metal component or a hollow profile.

8. The battery tray (1) according to any one of the preceding claims, characterized in that, The battery tray has a first anti-corrosion layer, particularly an AlSi-based first anti-corrosion layer, wherein a second anti-corrosion layer is provided on the first layer, preferably a cathodic electrodeposition coating (KTL) or a powder coating.

9. The battery tray (1) according to any one of the preceding claims, characterized in that, The front and rear sidewalls (4, 5) have different heights than the sidewalls on the sides of the vehicle, wherein the matching cover (7) or cover is also tray-shaped and complements the different sidewall heights.

10. The battery tray (1) according to any one of the preceding claims, characterized in that, Longitudinal and / or transverse reinforcing ribs (8, 9) are molded in the bottom (3).

11. A method for manufacturing the battery tray (1) according to claim 1, characterized in that, The following methods and steps are included: A slab (14) made of a hardenable steel alloy is provided. The subsequent corner regions of the sidewalls are subjected to partial or full austenitization and partial intercooling. The battery tray (1) is placed in a thermoforming and compressive hardening tool and thermoformed and compressive hardened, so that the tensile strength Rm of the battery tray (1) is greater than or equal to 1250 MPa, while the tensile strength of the corner region (10) is less than 1100 MPa.

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