Underbody protection element with external metal sheets and plastic core element, battery assembly and motor vehicle with such an underbody protection element

Abstract

A subbody protection element (10) for a motor vehicle (100) that is at least partially electrically powered is described, comprising at least one upper metal sheet (12) made of a first metal material; at least one lower metal sheet (14) made of a second metal material; a core element (16) made of a plastic material, in particular fiber-reinforced, arranged between the upper metal sheet (12) and the lower metal sheet (16); wherein the upper metal sheet (12) and the lower metal sheet (14) each have an inner surface (12i, 14i) facing the core element (16) and in contact with it, and wherein the upper metal sheet (12) and the lower metal sheet (14) each have an outer surface (12a, 14a) facing away from the core element (16).It is provided that the inner surfaces (12i, 14i) of the upper metal sheet (12) and the lower metal sheet (14) are connected to the core element (16) by means of an adhesion promoter layer and / or that the upper metal sheet (12) and the lower metal sheet (14) have several positive-locking openings (12f, 14f) in which plastic material of the core element (16) is received. Furthermore, a battery assembly with such an underbody protection element (10) and a motor vehicle are described.

Description

[0001] The invention relates to an underbody protection element for a motor vehicle that is at least partially electrically powered, comprising at least one upper metal sheet made of a first metal material; at least one lower metal sheet made of a second metal material; a core element made of a plastic material, in particular fiber-reinforced, arranged between the upper metal sheet and the lower metal sheet; wherein the upper metal sheet and the lower metal sheet each have an inner surface facing the core element and in contact with it, and wherein the upper metal sheet and the lower metal sheet each have an outer surface facing away from the core element.

[0002] Such an underbody protection element is known, for example, as an underride guard from DE 10 2017 221 345 A1. Reference is also made to DE 10 2017 000 266 A1.

[0003] For optimal functionality of an underbody protection element, high flexural stiffness with minimal installation space is required. This can be achieved in particular through the use of fiber-reinforced composite materials in a sandwich construction, which, however, is associated with high costs. Alternatively, it is possible to use metal sheets and embed them in the plastic material so that they are completely surrounded by it.

[0004] The object underlying the invention is seen as being to provide an underbody protection element made of a plastic material, in particular injection molded, which can be manufactured simply and cost-effectively, and which can meet functional requirements with regard to flexural stiffness and installation space requirements.

[0005] This problem is solved by an underbody protection element, a battery arrangement, and a motor vehicle with the features of the respective independent patent claim. Advantageous embodiments with expedient further developments are specified in the dependent patent claims.

[0006] The proposed underbody protection element for a motor vehicle that is at least partially electrically powered comprises at least one upper metal sheet made of a first metal material; at least one lower metal sheet made of a second metal material; a core element made of a plastic material, in particular fiber-reinforced, arranged between the upper metal sheet and the lower metal sheet; wherein the upper metal sheet and the lower metal sheet each have an inner surface facing the core element and in contact with it, and wherein the upper metal sheet and the lower metal sheet each have an outer surface facing away from the core element.It is provided that the inner surfaces of the upper metal sheet and the lower metal sheet are connected to the core element by means of an adhesion promoter layer and / or that the upper metal sheet and the lower metal sheet have several positive-locking openings in which plastic material of the core element is received.

[0007] This provides a reliable connection between the core element and the metal sheets, whereby, in particular, the positive locking openings allow for a positive locking connection between the metal sheets and the core element in addition to a material-locking connection.

[0008] The metal sheets can be made of materials such as stainless steel or aluminum, or, in particular, corrosion-resistant or corrosion-free metal alloys. Furthermore, the metal sheets can have a thickness of approximately 0.3 to 3 millimeters.

[0009] The form-fitting openings in the underbody protection element can be circular or slot-shaped.

[0010] The total opening area formed by the positive-locking openings can amount to approximately 1 to 5%, and in particular 2 to 3%, of the total area of ​​the respective metal sheet. In other words, the respective metal sheet has continuous or solid areas covering approximately 95 to 99% of its total area.

[0011] In the underbody protection element, the interlocking openings of the upper metal sheet can be offset from the interlocking openings of the lower metal sheet. In other words, the underbody protection element has a structure in which the lower metal sheet has a continuous, full-surface, or solid area where the upper metal sheet has an interlocking opening above the core element, and vice versa. Therefore, with respect to height, there is no area within the surfaces of the metal sheets of the underbody protection element where only plastic material is present; rather, at every point, at least the upper or at least the lower metal sheet is present.

[0012] In the underbody protection element, the interlocking openings in the respective metal sheet can be arranged, at least partially, in a regular pattern. For example, circular interlocking openings can be arranged in a regular grid. The interlocking openings in the upper metal sheet can be arranged in a grid that is offset from the grid of the interlocking openings in the lower metal sheet. By way of example, circular interlocking openings can have a diameter of 2 to 3 millimeters, with the interlocking openings spaced approximately 10 to 30 millimeters apart.

[0013] In the underbody protection element, at least some of the positive-locking openings on the inner side facing the core element can have a collar section oriented towards the core element. This can support or improve the positive-locking connection between the metal sheet in question and the core element.

[0014] The underbody protection element can have several reinforcing elements on its inner surface of the upper metal sheet, designed to create a local thickening in certain areas. This results in the core element made of plastic being slightly thinner in the area of ​​the reinforcing elements. The reinforcing elements can be made of a metal or a flame-retardant material.

[0015] The underbody protection element may have an edge section surrounding the metal sheets, which is made of a plastic material, in particular the same plastic material as the core element or a flame-retardant plastic material. The edge section serves, in particular, to connect the underbody protection element to adjacent components of the vehicle, especially the battery box and sills.

[0016] In the underbody protection element, at least one of the metal sheets, in particular the lower metal sheet, can be dimensioned such that it is at least partially arranged in the edge section, in particular having a formed sheet section that is adapted to a shape of the edge section.

[0017] The underbody protection element can have several rib-like or pin-like support sections that are integrally connected to the core element in the area of ​​the positive-locking openings and protrude from the outside of the upper metal sheet. This allows forces to be better distributed to overlying structures, such as a battery box or battery housing, via the rib-like or pin-like support sections.

[0018] Furthermore, a battery arrangement for a motor vehicle that is at least partially electrically powered is proposed, comprising a battery storage unit housed in a battery box, wherein the battery storage unit has several battery cells, each having degassing openings, and an underbody protection element described above, wherein the positive locking openings of the upper metal sheet are arranged such that continuous areas of the outside of the upper metal sheet are arranged below each degassing opening.

[0019] A motor vehicle with at least a partially electric drive can be equipped with such a battery arrangement.

[0020] Further advantages and details of the invention will become apparent from the following description of embodiments with reference to the figures. These show: Fig. 1 a simplified and schematic sectional view of a section of an underbody protection element; Fig. 2 a simplified and schematic top view of an upper metal sheet and a lower metal sheet of the underbody protection element; Fig. 3 a simplified and schematic sectional view of a battery arrangement with an underbody protection element in a motor vehicle; Fig. 4 A simplified and schematic sectional view of a battery arrangement with an underbody protection element in a motor vehicle and a simplified top view of the underbody protection element.

[0021] In Fig. Figure 1 shows a simplified and schematic sectional view of an underbody protection element 10.

[0022] The underbody protection element 10 has an upper metal sheet 12 made of a first metal material and a lower metal sheet 14 made of a second metal material. A core element 16, made of a plastic material, in particular fiber-reinforced plastic, is arranged between the upper metal sheet 12 and the lower metal sheet 14.

[0023] The upper metal sheet 12 has an inner surface 12i facing the core element 16. The lower metal sheet 14 has an inner surface 14i facing the core element 16. In other words, the respective inner surfaces 12i, 14i of the upper and lower metal sheets 12, 14 face each other with the core element 16 interposed.

[0024] The upper metal sheet has an outer surface 12a facing away from the core element 16. The lower metal sheet 14 has an outer surface 14a facing away from the core element 16.

[0025] The respective inner surfaces 12i, 14i of the upper and lower metal sheets 12, 14 can be connected to the core element 16 by means of an adhesion promoter layer not shown.

[0026] Alternatively or additionally, the upper metal sheet 12 can have several positive-locking openings 12f in which plastic material of the core element 16 is received. Furthermore, alternatively or additionally, the lower metal sheet 14 can have several positive-locking openings 14f in which plastic material of the core element 16 is received.

[0027] In Fig. 2 are, in A), a simplified and schematic top view of the underbody protection element 10 corresponding to arrow IIA of the Fig. 1 and in B) a simplified and schematic top view from below of the underbody protection element 10 corresponding to arrow IIB of the Fig. 1 shown.

[0028] From the Fig. Figure 2 shows that the respective outer surfaces 12a, 14a of the upper and lower metal sheets 12, 14 are visible in the respective top view. In other words, the outer surfaces 12a, 14a are visible and at least predominantly not covered by the plastic material of the core element 16. Furthermore, the form-fitting openings 12f, 14f, which are filled with the plastic material of the core element 16, are also visible in the top views.

[0029] Viewed from the outside, the underbody protection element 10 thus has a predominantly metallic structure, formed by the two metal sheets 12, 14, with small planar portions of the plastic material of the core element 16 visible in the areas of the form-fitting openings 12f, 14f.

[0030] With regard to the upper metal sheet 12, it is made of the Fig. 1 and Fig. 2 can be seen that the form-fitting openings 12f can be circular, strip-shaped, slot-shaped or the like.

[0031] From the combination of views A) and B) of the Fig. 2, but also from the sectional view of the Fig. As can be seen in Figure 1, the positive locking openings 12f of the upper metal sheet 12 are arranged offset from the positive locking openings 14f of the lower metal sheet 14.

[0032] Referring to the sectional view of the Fig. This means that the underbody protection element 10, in the area of ​​the metal sheets 12, 14, is designed such that at least one of the metal sheets 12, 14 is present at every point in the vertical direction Z. In other words, the core element 16 of the underbody protection element 10, in the area of ​​the metal sheets 12, 14, is not designed to extend continuously from the respective inner side 12i, 14i to the respective outer side 12a, 14a at the same point. With regard to the overall height or thickness of the underbody protection element 10, it can therefore be said that the overall height or thickness of the area of ​​the metal sheets 12, 14 is not entirely formed by the plastic material of the core element 16.

[0033] The positive-locking openings 12f, 14f of the upper and lower metal sheets 12, 14 can be arranged, in particular, in a regular pattern or grid. The patterns or grids of the upper metal sheet 12 and the lower metal sheet 14 can be offset from one another. It is also possible that the pattern or grid of the positive-locking openings 12f of the upper metal sheet differs from the pattern or grid of the positive-locking openings 14f of the lower metal sheet 14.

[0034] Regarding the Fig. 2B, for example, it is conceivable that a metal sheet, here the lower metal sheet 14, has fewer positive locking openings 14f because these are arranged at a greater distance from each other, as is illustrated purely by way of example in two of the four vertical rows of positive locking openings 14f.

[0035] From the sectional view of the Fig. It is further evident from Figure 1 that at least some of the positive-locking openings 12f, 14f can have a collar section 12k, 14k oriented towards the core element 16 on the inner side 12i, 14i facing the core element 16. This improves the positive-locking connection between the core element 16 and the metal sheet 12, 14 in question.

[0036] In Fig. Figure 3 shows a simplified and schematic sectional view of a battery arrangement 20 for a motor vehicle 100 that is at least partially electrically powered.

[0037] The battery assembly 20 comprises several battery storage units 24, which are housed in a battery box 22. Each battery storage unit 24 comprises several battery cells 24z. The battery storage units 24 can also be referred to as battery cell stacks or battery cell clusters. The battery cells 24z each have a degassing opening 26.

[0038] The battery arrangement 20 further comprises an underbody protection element 10, which has a structure as described above in general terms with reference to the Fig. 1 and Fig. 2 has been described.

[0039] From the perspective of Fig. 3 shows that the positive locking openings 12f of the upper metal sheet 12 are arranged such that a continuous area of ​​the outer surface 12a of the upper metal sheet 12 is arranged below each degassing opening 26.

[0040] From the Fig. Figure 3 further shows that the underbody protection element 10 has a circumferential edge section 30, which may be made of the same plastic material as the core element 16. The circumferential edge section 30 may also be made of a flame-retardant plastic material that is compatible with the (non-flame-retardant) plastic material of the core element 16 with regard to a material-bonded connection between the core element 16 and the edge section 30.

[0041] For example, the left marginal section 30 in Fig. Figure 3 illustrates that at least one of the metal sheets 12, 14, in particular the lower metal sheet 14, is dimensioned such that it is at least partially located in the edge section 30. In other words, the metal sheet 14 in question can have a formed sheet section 14r or sheet edge that is adapted to the shape of the edge section 30.

[0042] Even if a formed sheet metal section 14r or sheet metal edge is in the Fig. 3 shown only for the left edge section 30, such a sheet metal section 14r can be formed on two sides of the metal sheet 14 or on all (four) sides of the metal sheet 14, i.e. in particular around the perimeter.

[0043] The upper metal sheet 12 can also have such formed sheet metal sections, even if this is shown in the Fig. 3 is not explicitly shown.

[0044] The lower metal sheet 14 (and / or the upper metal sheet 12) can thus extend into the edge section 30. This can be achieved by 3D forming of the sheet section 14r. In a final underbody protection element 10, the metal sheet 14 projecting into the edge section 30 is typically about 2 to 10 mm shorter than the plastic edge or edge section 30 of the underbody protection element 10.

[0045] In the Fig. Figure 3 below the centrally illustrated battery cell 24z indicates that the upper metal sheet 12 may have reinforcing elements 12v on its inner side 12i, which are arranged to form a local thickening on the upper metal sheet 12 in certain areas.

[0046] Such reinforcing elements 12v can be arranged, in particular, in those areas of the upper metal sheet 12 that lie below the degassing openings 26 of the battery cells 24z. The reinforcing elements 12i can, for example, be metallurgically bonded to the metal sheet 12. In particular, the reinforcing elements 12v can be another metal sheet that can be welded or bonded to the metal sheet 12.

[0047] From the Fig. 3 It is further evident that the underbody protection element 10 can have several rib-like support sections 28 which are located in the area of ​​positive locking openings 12f, in particular strip-like positive locking openings 12f (see Fig. 2A) are integrally connected to the core element 16 and project from the outer surface 12a of the upper metal sheet 12. The support elements 28 serve in particular for storage or support on the battery box 22.

[0048] In Fig. In Figure 3, the 24z battery cells are depicted as prismatic or cuboid-like blocks. However, it is also possible that the battery cells are cylindrical and arranged next to each other in clusters, as shown for example in Figure 3. Fig. 4 is illustrated.

[0049] In Fig. Figure 4 shows an essentially identical sectional view of the battery arrangement 20 as in the A). Fig. 3. In Fig. Figure 4 shows a simplified top view of the upper metal sheet 12 of the underbody protection element 10, with battery cells 24z arranged above the metal sheet 12 indicated as dashed circles.

[0050] The example of Fig. Figure 4 illustrates a battery arrangement 20 in which the battery cells 24z have a cylindrical shape. Each of the cylindrical battery cells 24z has a respective degassing opening 26.

[0051] The underbody protection element 10 can have several pin-like or rib-like support sections 28 which are integrally connected to the core element 16 in the area of ​​the positive locking openings 12f and protrude from the outside 12a of the upper metal sheet 12.

[0052] In B) the Fig. Four different examples of the design of support sections 28 are illustrated. In an upper row, cylindrical or pin-like support sections 28 are shown. In a lower row, angled, rib-like support sections 28 are illustrated, which can bear at least partially against an outer surface of the battery cells 24z or can be arranged in the free space between the battery cells 24z.

[0053] The support sections 28 can also have other shapes. For example, the support sections 28 (top row), which are circular in cross-section, can also be polygonal, e.g., triangular or hexagonal, so that they have a prismatic shape. For example, the support sections 28 shown at an angle (bottom row) can also be curved, in particular bent concentrically with respect to the cylindrical battery cells 24z.

[0054] The underbody protection element 10, as described above with reference to the Fig. As described in sections 1 to 4, the metal sheets 12 and 14 can be made of the same metal or of different metals. Stainless steel or aluminum, in particular, can be used as metals.

[0055] The plastic material of the core element 16 can, in particular, be a fiber-reinforced thermoplastic material, especially polypropylene, polyethylene, or the like. The [material] in the Fig. 3 and Fig. 4. The visible edge section 30 of the underbody protection element 10 can be made of the same plastic material as the core element 16. Alternatively, the edge section 30 can also be made of a flame-retardant plastic material that, in particular, meets the classification V0, V1 according to the UL94 standard.

[0056] The underbody protection element 10 can be manufactured in particular in an injection molding process, wherein the upper metal sheet 12 and the lower metal sheet 14 are arranged in an injection molding device, and then, with the injection molding device closed, the plastic material is injected to form the core element 16 and fill the respective interlocking openings 12f, 14f of the metal sheets 12, 14, so that the metal sheets 12, 14 are materially and form-fittingly connected to the core element 16. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2017 221 345 A1

[0002] DE 10 2017 000 266 A1

[0002]

Claims

[1] Underbody protection element (10) for a motor vehicle (100) that is at least partially electrically powered at least one upper metal sheet (12) made of a first metal material; at least one lower metal sheet (14) made of a second metal material; a core element (16) arranged between the upper metal sheet (12) and the lower metal sheet (16) made of a plastic material, in particular fiber-reinforced; wherein the upper metal sheet (12) and the lower metal sheet (14) each have an inner surface (12i, 14i) facing the core element (16) and in contact with it, and wherein the upper metal sheet (12) and the lower metal sheet (14) each have an outer surface (12a, 14a) facing away from the core element (16), characterized by, that the inner surfaces (12i, 14i) of the upper metal sheet (12) and the lower metal sheet (14) are connected to the core element (16) by means of an adhesion promoter layer and / or the upper metal sheet (12) and the lower metal sheet (14) have several positive locking openings (12f, 14f) in which plastic material of the core element (16) is received. [2] Underbody protection element (10) according to claim 1, characterized by , that the form-fitting openings (12f, 14f) are circular or slot-shaped. [3] Underbody protection element (10) according to claim 1 or 2, characterized by , that the positive locking openings (12f) of the upper metal sheet (12) are arranged offset from the positive locking openings (14f) of the lower metal sheet (14). [4] Underbody protection element (10) according to any one of the preceding claims, characterized by, that the form-fitting openings (12f, 14f) in the respective metal sheet (12, 14) are at least partially arranged in the manner of a regular pattern. [5] Underbody protection element (10) according to any one of the preceding claims, characterized by , that the upper metal sheet (12) has several reinforcing elements (12v) on its inner side (12i) which are designed to form a local thickening on the upper metal sheet (12) in certain areas. [6] Underbody protection element (10) according to one of the preceding claims, characterized by , that it has a circumferential edge section (30) made of a plastic material, in particular of the same plastic material as the core element (16) or of a flame-resistant plastic material. [7] Underbody protection element (10) according to claim 6, characterized by, that at least one of the metal sheets (12, 14), in particular the lower metal sheet (14), is dimensioned such that it is at least partially arranged in the edge section (30), in particular having a formed sheet section that is adapted to a shape of the edge section (30). [8] Underbody protection element (10) according to one of the preceding claims, characterized by , that it has several rib-like or pin-like support sections (28) which are integrally connected to the core element (16) in the area of ​​the positive locking openings (12f) and project from the outside (12a) of the upper metal sheet (12). [9] Battery arrangement (20) for a motor vehicle (100) that is at least partially electrically powered, comprising a battery storage unit (24) housed in a battery box (22), wherein the battery storage unit (24) comprises several battery cells (24z) which have respective degassing openings (26), and comprising an underbody protection element (10) according to one of the preceding claims, wherein the positive locking openings (12f) of the upper metal sheet (12) are arranged such that continuous areas of the outside (12a) of the upper metal sheet (12) are arranged below a respective degassing opening (26). [10] Motor vehicle (100) with at least a partially electric drive and with a battery arrangement (20) according to claim 9.

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