Underbody protection for a motor vehicle, battery housing for a traction battery, traction battery for a motor vehicle, and motor vehicle having underbody protection

Abstract

The invention relates to underbody protection (1) for a motor vehicle, wherein the underbody protection (1) has a sandwich reinforcement element (100), wherein the sandwich reinforcement element (100) has a central region (101) and an edge region (102), peripherally enclosing the central region, and also an outer layer (110) and an inner layer (150), each of which comprises a plastic, and a metal layer (130). The metal layer (130) is connected to the outer layer (110) by means of a first adhesion-promoter layer (120). Furthermore, the metal layer (130) is connected to the inner layer (150) and is sandwiched between the outer layer (110) and the inner layer (150), wherein the outer layer (110) has a greater thickness extent than the inner layer (150), and wherein the thickness extent of the outer layer (110) is at least 30% of a total thickness extent of the sandwich reinforcement element (100).

Description

[0001] Page 1 of 34

[0002] Applicant: KAUTEX TEXTRON GmbH & Co. KG

[0003] Our reference number: P81144WO

[0004] December 10, 2024

[0005] Underbody protection for a motor vehicle, battery housing for a traction battery, traction battery for a motor vehicle, motor vehicle with underbody protection

[0006] The present invention relates to underbody protection for motor vehicles, in particular for electric vehicles. Furthermore, the present invention relates to a battery housing for a traction battery. The present invention also relates to a traction battery for a motor vehicle. Finally, the present invention relates to a motor vehicle, in particular an electric vehicle, with underbody protection.

[0007] Various types of underbody protection systems are known from the prior art. Heavy steel plates or welded steel assemblies are predominantly used as underbody protection to absorb the high intrusion force and impact energy when motor vehicles dynamically strike obstacles. Furthermore, underbody protection must be able to withstand highly dynamic forces, such as those typically generated by a trailer's outrigger in the event of a collision. Such underbody protection systems increase the vehicle's overall weight. Additionally, steel underbody protection is more susceptible to corrosion. Finally, steel underbody protection has low chemical resistance to components of battery cells and / or battery modules, particularly to electrolytes. Page 2 / 34

[0008] P81144WO

[0009] To address corrosion problems, underbody protection systems are known in the prior art, whose metal plates are protected by an outer plastic layer. However, such underbody protection systems suffer from the problem of mechanical distortion during production and / or temperature changes. Therefore, it is common practice for prior art underbody protection systems to have a metal plate with a thickness of 50% or more of the total thickness of the underbody protection system. This prevents distortion and ensures high impact resistance to both quasi-static and highly dynamic loads. Such underbody protection systems are heavy and offer limited design freedom.

[0010] The invention is based on the objective of providing an underbody protection system that exhibits high stiffness and energy absorption capacity in both essentially quasi-static and highly dynamic intrusion situations, while simultaneously having low weight and, in addition, increased resistance to corrosion and chemical stresses.

[0011] The problem underlying the invention is solved by an underbody protection system with the features of claim 1. Advantageous embodiments of the underbody protection system are described in the dependent claims.

[0012] More precisely, the problem underlying the invention is solved by an underbody protection for a motor vehicle, wherein the underbody protection has a sandwich reinforcement element, wherein the sandwich reinforcement element has a central area and an edge area surrounding it, an outer layer and an inner layer, each comprising a plastic, and a metal layer, wherein the metal layer (page 3 / 34)

[0013] P81144WO is connected to the outer layer by means of a first adhesion promoter layer, and wherein the metal layer is connected to the inner layer and is arranged sandwich-like between the outer layer and the inner layer, wherein the outer layer has a greater thickness extent than the inner layer, and wherein the thickness extent of the outer layer is at least 30% of a total thickness extent of the sandwich reinforcement element.

[0014] The underbody protection according to the invention exhibits high impact resistance to both quasi-static and highly dynamic impacts. Furthermore, the underbody protection according to the invention has a reduced weight, since the metal layer is thinner compared to underbody protection systems known from the prior art. Due to the relatively thick outer layer in relation to the overall thickness of the underbody protection, the metal layer can be thinner. Moreover, the reduced thickness of the metal layer allows for greater design freedom, particularly in 3D design.

[0015] The metal layer preferably comprises aluminum and / or iron and / or steel. More preferably, the metal layer is formed as an aluminum layer or aluminum plate. More preferably, the metal layer is formed as an iron layer or iron plate. More preferably, the metal layer is formed as a steel layer or steel plate. More preferably, the metal layer, in particular a steel layer or steel plate, is galvanized.

[0016] The inner layer preferably comprises a thermoplastic material. More preferably, the inner layer is designed as an adhesion promoter layer.

[0017] The inner layer and / or the outer layer preferably comprises a self-reinforcing plastic. A self-reinforcing plastic is a composite material, which consists of page 4 / 34.

[0018] P81144WO consists of highly oriented and compacted polymer fibers that are embedded in a polymer matrix.

[0019] The inner layer and / or the outer layer preferably comprises a thermoplastic polymer as the matrix material and glass fibers and / or carbon fibers and / or aramid fibers as fiber material distributed within the matrix material. The fiber material can be short fiber material and / or long fiber material and / or continuous fiber material in the inner layer and / or the outer layer. The thermoplastic polymer preferably comprises polypropylene and / or polyamide.

[0020] The inner layer and / or the outer layer is / are preferably designed as a cross-ply. Preferably, the inner layer and / or the outer layer comprises a plurality of fiber layers, wherein at least two directly adjacent fiber layers each have reinforcing fibers whose longitudinal extensions each form an angle with each other other than 0°, preferably 90°.

[0021] The first adhesion promoter layer preferably comprises a polypropylene grafted with maleic acid and / or maleic anhydride and / or polyacrylic acid.

[0022] The outer layer is bonded to the metal layer by means of the first adhesion promoter layer.

[0023] The sandwich reinforcement element can also be referred to as an insert. This is because, to manufacture the underbody protection according to the invention, the sandwich reinforcement element is preferably inserted into an injection mold (hence the term "insert") and then brought into contact at predetermined points with thermoplastic material forming further functional components. Page 5 / 34

[0024] P81144WO

[0025] Preferably, the matrix material of the inner layer is a transparent thermoplastic. More preferably, the fiber material is a glass fiber material. A correspondingly designed underbody protection has the advantage that the underbody protection, and in particular the metal layer, can be easily inspected visually, which can be particularly important when punching and / or cutting recesses and for quality control.

[0026] The total thickness of the sandwich reinforcement element is the sum of the thicknesses of the outer layer, the first adhesion promoter layer, the metal layer, and the inner layer.

[0027] More preferably, the thickness of the outer layer is at least 40%, more preferably at least 50%, and particularly preferably at least 60% of the total thickness of the sandwich reinforcement element.

[0028] Preferably, the metal layer is bonded to the inner layer by means of a second adhesion promoter layer.

[0029] With appropriately designed underbody protection, the total thickness of the sandwich reinforcement element is the sum of the thicknesses of the outer layer, the first adhesion promoter layer, the metal layer, the second adhesion promoter layer and the inner layer.

[0030] The second adhesion promoter layer preferably comprises a polypropylene grafted with maleic acid and / or maleic anhydride and / or polyacrylic acid.

[0031] The metal layer is bonded to the inner layer by means of the second adhesion promoter layer. Page 6 / 34

[0032] P81144WO

[0033] Preferably, the underbody protection is designed such that the outer layer extends to an outer edge that limits the sandwich reinforcement element and the metal layer ends before the outer edge of the sandwich reinforcement element.

[0034] The appropriately designed underbody protection exhibits increased resistance to corrosion of the metal layer.

[0035] Preferably, the inner layer also extends to the outer edge of the sandwich reinforcement element. The correspondingly designed underbody protection exhibits further improved corrosion resistance, as the metal layer is even better protected against contact with liquids and humidity, particularly before functionalization by overmolding or overmolding with a thermoplastic material in an injection molding or flow-forming tool.

[0036] Preferably, the underbody protection is designed such that the inner layer ends before the edge area of ​​the sandwich reinforcement element, and that the sandwich reinforcement element has a replacement inner layer that adjoins the inner layer and extends into the edge area of ​​the sandwich reinforcement element.

[0037] The correspondingly designed underbody protection offers even greater design freedom, particularly in 3D design. For example, with a shell-shaped underbody protection, bending the sandwich reinforcement element in an injection molding or flow-forming tool allows the inner layer to be thinned and thus weakened in the bending area of ​​the sandwich reinforcement element, and therefore of the underbody protection itself. The edge area of ​​the sandwich reinforcement element is the area that is bent. The central area of ​​page 7 / 34

[0038] P81144WO

[0039] The sandwich reinforcement element is the area that is essentially flat or even. Furthermore, a correspondingly designed underbody protection can be processed more effectively, since no gaps or free spaces remain in the underbody protection due to the omission of the inner layer at the edge of the sandwich reinforcement element.

[0040] The replacement inner layer preferably comprises a fiber-reinforced plastic. More preferably, the replacement inner layer is a cross-ply. Even more preferably, the replacement inner layer has the same structure as the inner layer. Even more preferably, the replacement inner layer has the same thickness as the inner layer.

[0041] Preferably, the underbody protection is designed such that the metal layer ends before the edge area of ​​the sandwich reinforcement element, and that the sandwich reinforcement element has a substitute middle layer that adjoins the metal layer and extends into the edge area of ​​the sandwich reinforcement element.

[0042] The underbody protection system designed accordingly offers even greater design freedom, particularly in 3D design. For example, with a shell-shaped sandwich reinforcement element (and thus underbody protection), bending the element in an injection mold allows the metal layer to be thinned and weakened in the bending area. Furthermore, this type of underbody protection system can be processed more effectively because no gaps or voids remain in the underbody protection system due to the omission of the metal layer at the edges of the sandwich reinforcement element. Page 8 / 34

[0043] P81144WO

[0044] The replacement core layer preferably comprises a fiber-reinforced plastic. More preferably, the replacement core layer is a cross-ply. Even more preferably, the replacement core layer has the same thickness as the metal layer.

[0045] Preferably, the underbody protection is designed such that the metal layer extends to the edge area of ​​the sandwich reinforcement element.

[0046] The underbody protection system designed accordingly has a simplified structure and is easier to manufacture compared to the version described above.

[0047] Preferably, the underbody protection is designed such that the sandwich reinforcement element is shell-shaped, with the central area forming a shell base and the outer area a shell rim of the sandwich reinforcement element. Preferably, the underbody protection is designed to accommodate battery cells and / or battery modules.

[0048] The appropriately designed underbody protection exhibits even improved stiffness and stability.

[0049] Preferably, the underbody protection is designed such that the outer layer has a thickness between 0.5 mm and 3 mm, preferably 2 mm, and that the metal layer has a thickness between 0.3 mm and 1 mm, preferably 0.6 mm, and that the inner layer has a thickness between 0.15 mm and 0.7 mm, preferably 0.45 mm, and that the first adhesion promoter layer and the second adhesion promoter layer each have a thickness between 0.05 mm and 0.2 mm, preferably 0.1 mm. Page 9 / 34

[0050] P81144WO

[0051] The inventors have discovered that, surprisingly, an underbody protection system with appropriately dimensioned inner, metal and outer layers, despite its compact and therefore lightweight design, still exhibits high impact resistance to both quasi-static and highly dynamic impacts.

[0052] Preferably, the underbody protection is designed such that the outer layer has a cross-ply with a plurality of fiber layers, wherein at least two directly adjacent fiber layers each have reinforcing fibers whose longitudinal extensions each enclose an angle to each other other than 0°, preferably 90°, wherein the reinforcing fibers of the fiber layer bounding the outer layer are aligned parallel to a longitudinal axis of the underbody protection, wherein the longitudinal axis of the underbody protection in the installed state in a motor vehicle is parallel to the direction of travel of the motor vehicle.

[0053] The inventors discovered that the specially designed underbody protection surprisingly exhibits increased impact resistance to highly dynamic impacts, such as those caused by a trailer striking the vehicle and thus the underbody protection in a frontal collision. This is because the fibers of the outer layer are aligned parallel to the direction of the impact, thereby improving structural integrity.

[0054] The fiber layer that forms the outer boundary is the fiber layer of the outer layer furthest from the inner layer. Page 10 / 34

[0055] P81144WO

[0056] Preferably, the underbody protection is designed such that the sandwich reinforcement element is at least partially overmolded or flowed over with a thermoplastic material, so that the thermoplastic material is connected to the edge area of ​​the sandwich reinforcement element, preferably in a bonded manner, forming a connecting flange of the underbody protection.

[0057] The appropriately designed underbody protection can be easily connected to a battery housing component, in which, for example, battery cells and / or battery modules can be accommodated.

[0058] Preferably, the underbody protection is designed such that a groove for receiving a fluid sealing element is formed in a connecting surface of the connecting flange.

[0059] The specially designed underbody protection exhibits improved sealing. The fluid sealing element seals against the thermoplastic material forming the connecting flange, and thus against a smooth surface, resulting in a good sealing effect. If the fluid sealing element were in contact with the inner layer of the sandwich reinforcement element, the sealing effect would be reduced.

[0060] Preferably, the groove has a V-shaped cross-section.

[0061] Further preferably, the underbody protection is designed such that the sandwich reinforcement element is overmolded or flowed over with the thermoplastic material in such a way that the thermoplastic material is connected to the outer layer in the edge region of the sandwich reinforcement element by forming a plurality of reinforcing ribs, preferably in a material-bonded manner, so that the reinforcing ribs are on one of the page 11 / 34

[0062] P81144WO

[0063] The connecting surface is arranged on the opposite side of the edge area of ​​the sandwich reinforcement element.

[0064] The appropriately designed underbody protection exhibits increased rigidity, particularly in the area of ​​its connecting flange. This allows for a larger connecting flange and a larger connecting surface, thus providing more freedom in designing its functionality.

[0065] Furthermore preferably, the underbody protection is designed such that the connecting flange has at least one connecting flange section, preferably four connecting flange sections, wherein the groove in the connecting surface of this connecting flange section runs straight and continuously.

[0066] The correspondingly designed underbody protection is easier to manufacture compared to prior art underbody protection systems, because in the prior art underbody protection systems both the groove and the fluid sealing element held in the groove are meander-shaped to prevent the groove and the fluid sealing element from colliding with screws driven through the connecting flange. This meander-shaped design is necessary in prior art underbody protection systems because the connecting flange, due to its reduced stiffness, is smaller (thinner and less high), so that the available connecting surface can be optimally utilized by a meander-shaped groove.

[0067] Preferably, the underbody protection is designed such that the connecting flange has a plurality of connecting devices for driving a screw through each one, wherein the connecting surface has recesses through which the respective screws can be driven. Page 12 / 34

[0068] P81144WO

[0069] The specially designed underbody protection is particularly easy to connect to another battery housing component, with fluid tightness also being ensured thanks to the cutouts. This is because, when a screw is driven through the connecting flange, any material expelled by the screw is collected in the respective cutouts, so that the expelled material does not lie between the sealing surfaces of the connecting flange and the other battery housing component.

[0070] Preferably, the underbody protection is designed such that the sandwich reinforcement element is overmolded or coated with a thermoplastic material in such a way that the thermoplastic material is connected to the inner layer in the central area of ​​the sandwich reinforcement element by forming a plurality of internal ribs, preferably in a materially bonded manner.

[0071] The appropriately designed underbody protection exhibits increased rigidity, particularly in its central area or receiving space. Therefore, the underbody protection can be made larger.

[0072] Preferably, the underbody protection is designed such that the majority of the inner ribs have first inner ribs and second inner ribs, wherein end regions of the first inner ribs define a first bend line, and wherein end regions of the second inner ribs define a second bend line that does not coincide with the first bend line.

[0073] The appropriately designed underbody protection exhibits increased stability in the event of a high impact, such as that occurring in an accident. This is due to the [page 13 / 34]

[0074] P81144WO

[0075] The presence of several crease lines that do not coincide makes it more difficult to bend the underbody protection.

[0076] Preferably, the underbody protection is designed such that the majority of the inner ribs have at least a third inner rib extending from a first edge of the central area to a second edge of the central area.

[0077] The appropriately designed underbody protection exhibits increased stability in the event of a large impact, such as that which occurs in an accident.

[0078] Preferably, the underbody protection is designed such that the sandwich reinforcement element has at least one opening in the central area, wherein the sandwich reinforcement element is shaped in the area of ​​the at least one opening such that the sandwich reinforcement element extends in the direction of a receiving space of the underbody protection bounded by the inner layer, and wherein the sandwich reinforcement element is overmolded or overmolded with a thermoplastic material in the area of ​​its at least one opening such that the thermoplastic material at least partially receives the sandwich reinforcement element in the area of ​​its at least one opening, forming a funnel.

[0079] The appropriately designed underbody protection can be even more effectively connected to a battery housing component, such as a battery housing shell. This is because the opening allows fasteners to be passed through for connection to the battery housing component. Furthermore, the appropriately designed underbody protection is more dimensionally stable when installed with a battery housing component, as the connection forces do not have to be transmitted solely via the connecting flange. Page 14 / 34

[0080] P81144WO

[0081] Further preferably, the underbody protection is designed such that the inner layer ends in front of an opening edge that limits the at least one opening of the sandwich reinforcement element, wherein the sandwich reinforcement element has a replacement inner layer that adjoins the inner layer and extends to the opening edge of the at least one opening of the sandwich reinforcement element.

[0082] The appropriately designed underbody protection offers even greater design freedom, particularly in 3D design. This is because, with a sandwich reinforcement element, bending it in an injection mold can thin and thus weaken the inner layer in the bending area of ​​the sandwich reinforcement element.

[0083] The replacement inner layer preferably comprises a fiber-reinforced plastic. More preferably, the replacement inner layer is a cross-ply. Even more preferably, the replacement inner layer has the same structure as the inner layer. Even more preferably, the replacement inner layer has the same thickness as the inner layer.

[0084] Further preferably, the underbody protection is designed such that the metal layer ends in front of an opening edge that limits the at least one opening of the sandwich reinforcement element, wherein the sandwich reinforcement element has a substitute middle layer that adjoins the metal layer and extends to the opening edge of the at least one opening of the sandwich reinforcement element.

[0085] The correspondingly designed underbody protection offers even greater design freedom, particularly in 3D design. This is because the sandwich reinforcement element, and thus the underbody protection, can be bent (see page 15 / 34).

[0086] P81144WO the metal layer in a bending area of ​​the sandwich reinforcement element is thinned and thus weakened by an injection molding or flow forming tool.

[0087] The substitute core layer preferably comprises a fiber-reinforced plastic. More preferably, the substitute core layer is a cross-ply. Even more preferably, the substitute core layer has the same thickness as the metal layer.

[0088] Preferably, the underbody protection is designed such that the outer layer, the metal layer and the inner layer extend to an opening edge that limits at least one opening of the sandwich reinforcement element.

[0089] The underbody protection system designed accordingly has a simplified structure and is easier to manufacture compared to the version described above.

[0090] Further preferably, the underbody protection is designed such that a funnel bottom formed by the thermoplastic material has a first funnel opening, and that the underbody protection has at least one reinforcing ring that limits the funnel opening and is enclosed at its edges by the thermoplastic material, and that a wall of the reinforcing ring has an L-shaped geometry in cross-section, wherein a first outer edge of the reinforcing ring, which is facing away from the funnel bottom, has a larger diameter than a second outer edge of the reinforcing ring, which is facing the funnel bottom.

[0091] The specially designed underbody protection offers even greater stability. Furthermore, it allows for a seal to the underside and prevents any loss of clamping force at low surface pressure in the screw connection. Page 16 / 34

[0092] P81144WO

[0093] The problem underlying the present invention is further solved by a battery housing for receiving battery cells and / or battery modules, wherein the battery housing has a battery housing shell which is designed as the underbody protection described above.

[0094] The problem underlying the present invention is further solved by a traction battery for a motor vehicle, wherein the traction battery comprises at least one battery cell and / or at least one battery module and a battery housing as described above, wherein the at least one battery cell and / or the at least one battery module is / are arranged in the battery housing.

[0095] The problem underlying the present invention is further solved by a motor vehicle, in particular an electric motor vehicle, with underbody protection which is designed according to one of the embodiments described above and which is attached to an underbody of the motor vehicle, in particular to a traction battery of the motor vehicle. Alternatively, the problem underlying the present invention is solved by a motor vehicle, in particular an electric vehicle, with a traction battery described above.

[0096] Further advantages, details, and features of the invention will become apparent from the illustrated examples below. Specifically, the following will be shown:

[0097] Figure 1: a schematic sectional view of a sandwich reinforcement element of an underbody protection according to the invention in a first embodiment; page 17 / 34

[0098] P81144WO

[0099] Figure 2: a schematic sectional view of a sandwich reinforcement element of an underbody protection according to the invention in a second embodiment;

[0100] Figure 3: a schematic sectional view of a sandwich reinforcement element of an underbody protection according to the invention in a third embodiment;

[0101] Figure 4: a schematic sectional view of an underbody protection according to the invention in partial view and in the area of ​​an edge of the underbody protection;

[0102] Figure 5: a schematic sectional view of an underbody protection according to the invention in partial view and in a central area of ​​the underbody protection;

[0103] Figure 6: a perspective view of an underbody protection system according to the invention; and

[0104] Figure 7: a top view of the underbody protection shown in Figure 6 into a receiving space of the underbody protection.

[0105] In the following description, identical reference symbols denote identical components or identical features, so that a description given for one component in relation to one figure also applies to the other figures, thus avoiding repetitive descriptions. Furthermore, individual features described in connection with one embodiment can also be used separately in other embodiments.

[0106] Figure 1 shows the schematic structure of a sandwich reinforcement element 100, which is part of a structure shown in Figure 4 on page 18 / 34.

[0107] P81144WO to 7 depicted underbody protection 1 is . The underbody protection 1 is preferably produced by inserting a sandwich reinforcement element 100 into an injection molding tool and subsequently partially overmolding the sandwich reinforcement element 100 with a thermoplastic material .

[0108] The sandwich reinforcement element 100 shown in Figure 1 has an outer layer 110 and an inner layer 150, each of which comprises a fiber-reinforced plastic. The sandwich reinforcement element 100 also has a metal layer 130, which is arranged sandwich-like between the outer layer 110 and the inner layer 150. The metal layer 130 is bonded to the outer layer 110 by means of a first bonding agent layer 120 and to the inner layer 150 by means of a second bonding agent layer 140.

[0109] It is evident that the outer layer 110 has a greater thickness than the inner layer 150. In the embodiment of the sandwich reinforcement element 100 shown in Figure 1, the thickness of the outer layer 110 is approximately 50% of the total thickness of the sandwich reinforcement element 100.

[0110] The sandwich reinforcement element 100 has a central area

[0111] 101, which is enclosed at its edges by an edge region 102. In the embodiment shown in Figure 1, the sandwich reinforcement element 100 is flat, so that the central region 101 and the edge region 102 are arranged in a common plane. Figure 1 also shows that the metal layer 130 extends into the edge region.

[0112] 102 of the sandwich reinforcement element 100 extends .

[0113] Figure 2 shows a schematic cross-sectional view of a sandwich reinforcement element 100 according to a further execution - page 19 / 34

[0114] P81144WO rungs form. The sandwich reinforcement element 100 is shell-shaped, with the central area 101 forming a shell base.

[0115] 101 and the edge area 102 form a shell edge 102 of the sandwich reinforcement element 100 .

[0116] Figure 2 shows that both the outer layer 110 and the inner layer 150 extend to an outer edge 103 that defines the sandwich reinforcement element 100, while the metal layer 130 terminates before the outer edge 103 of the sandwich reinforcement element 100. Thus, the outer edge of the metal layer 130 is better protected against corrosion.

[0117] Figure 3 shows a schematic cross-sectional view of a sandwich reinforcement element 100 according to a further embodiment. The sandwich reinforcement element 100 shown in Figure 3 is also shell-shaped, with the central area 101 forming a shell base 101 and the edge area

[0118] 102 form a shell edge 102 of the sandwich reinforcement element 100 .

[0119] In the sandwich reinforcement element 100 shown in Figure 3, the metal layer 130 terminates before the edge region 102 of the sandwich reinforcement element 100. The sandwich reinforcement element 100 has a substitute middle layer 131, which adjoins the metal layer 130 and extends into the edge region 102 of the sandwich reinforcement element 100. Furthermore, in the sandwich reinforcement element 100 shown in Figure 3, the inner layer 150 also terminates before the edge region 102 of the sandwich reinforcement element 100. The sandwich reinforcement element 100 has a substitute inner layer 151, which adjoins the inner layer 150 and extends into the edge region 102 of the sandwich reinforcement element 100. Of course, it is also possible that either only the inner layer (page 20 / 34)

[0120] P81144WO

[0121] 150 or the metal layer 130 ends before the edge region 102 of the sandwich reinforcement element 100. Furthermore, it is of course also possible that the sandwich reinforcement element 100 is planar, so that the central region 101 and the edge region 102 are arranged in a common plane.

[0122] In the sandwich reinforcement element 100 shown in Figure 3, both the metal layer 130 and the inner layer 150 terminate before a bend in the sandwich reinforcement element 100. The substitute middle layer 131 is connected to the outer layer 110 by means of the first adhesion promoter layer 120 and to the substitute inner layer 151 by means of the second adhesion promoter layer 140.

[0123] Figure 4 shows a portion of an underbody protection system 1 according to the invention for a motor vehicle in an edge region of the underbody protection system 1. A sandwich reinforcement element 100 is partially overmolded with a thermoplastic material to create various components of the underbody protection system 1, which will be discussed in more detail below. The sandwich reinforcement element 100 has a shell-like design. It can be seen that the metal layer 130 ends before the edge region 102 of the sandwich reinforcement element 100. The sandwich reinforcement element 100 has a substitute middle layer 131, already described above, which adjoins the metal layer 130 and extends into the edge region 102 of the sandwich reinforcement element 100.

[0124] The thermoplastic material injection-molded onto the edge region 102 of the sandwich reinforcement element 100 forms a connecting flange 10 of the underbody protection 1. A groove 12 is formed in a connecting surface 11 of the connecting flange 10, in which a fluid sealing element 20 is received. The groove 12 corresponds to a receiving space 2 of the underbody protection. Page 21 / 34

[0125] P81144WO

[0126] 1 adjacent and separated from the receiving space 2 by means of a material web 13. In the event of an intrusion by, for example, a projectile (a bollard or similar) in the area of ​​the groove 12, the material web 13 ensures that the receiving space 2 remains fluid-tight.

[0127] The underbody protection 1 further comprises a plurality of reinforcing ribs 30, which are formed by the thermoplastic material injection-molded onto the sandwich reinforcement element 100 on the outer layer 110 in the edge region 102 of the sandwich reinforcement element 100. The reinforcing ribs (30) are arranged on one side of the edge region 102 of the sandwich reinforcement element 100 opposite the connecting surface 11.

[0128] The connecting flange 10 also includes a plurality of connecting devices for driving through a screw each, wherein the connecting surface 11 has recesses 14 through which the respective screws (not shown in the figures) can be driven. In this way, material driven out of the connecting devices by the screws can be received by the recesses 14, so that this driven-out material does not negatively affect the sealing effect of the connecting flange 10.

[0129] Figure 5 shows a schematic cross-sectional view of the underbody protection 1 in a central area of ​​the underbody protection 1 as shown in Figure 7.

[0130] The sandwich reinforcement element 100 has at least one opening 160, preferably a plurality of openings 160, in the central area 101. It is evident that the sandwich reinforcement element 100 is shaped in the area of ​​the opening 160 such that the sandwich reinforcement element 100 extends in the direction of page 22 / 34.

[0131] P81144WO extends from the inner layer 150 into the receiving space 2 of the underbody protection 1. The sandwich reinforcement element 100 is overmolded with the thermoplastic material in the area of ​​its opening 160 such that the thermoplastic material receives the sandwich reinforcement element 100 in the area of ​​the opening 160, forming a funnel 60.

[0132] In the exemplary embodiment, the sandwich reinforcement element 100 is designed such that the metal layer 130 terminates before an opening edge 161 that defines the opening 160 of the sandwich reinforcement element 100. The sandwich reinforcement element 100 has a substitute middle layer 132 that adjoins the metal layer 130 and extends to the opening edge 161 of the sandwich reinforcement element 100.

[0133] Of course, it is also possible that the outer layer 110, the metal layer 130 and the inner layer 150 extend to the opening edge 161 that limits the opening 160 of the sandwich reinforcement element 100.

[0134] The funnel 60 has a funnel base 61, which in turn has a first funnel opening 62. The underbody protection 1 has a reinforcing ring 70 that delimits the funnel opening 62 and is encased at its edges by the thermoplastic material. The reinforcing ring 70 is designed such that one wall of the reinforcing ring 70 has an L-shaped geometry in cross-section, with a first outer edge 71 of the reinforcing ring 70, which faces away from the funnel base 61, having a larger diameter than a second outer edge 72 of the reinforcing ring 70, which faces the funnel base 61. A screw 90 is driven through the funnel opening 62 so that the underbody protection 1 can be connected to another battery housing component, for example, a battery tray (not shown). The screw, page 23 / 34

[0135] P81144WO

[0136] 90 is sealed against the funnel bottom 61 by means of a seal 91 .

[0137] Figure 6 shows a partial area of ​​the underbody protection 1 in perspective view, and Figure 7 shows the underbody protection 1 in top view, so that the receiving space 2 of the underbody protection 1 is visible.

[0138] The underbody protection 1 has a plurality of internal ribs 41, 42, 43 which are intrinsically connected to the inner layer 150 in the central area 101 of the sandwich reinforcement element 100. It is evident that the first internal ribs 41 and the second internal ribs 42 have different extensions. End regions of the first internal ribs 41 define first fold lines 51, and end regions of the second internal ribs 42 define second fold lines 52, which do not coincide with the first fold lines 52.

[0139] Figures 6 and 7 also show that the underbody protection 1 has third inner ribs 42, which extend from a first edge 101_l of the central area 101 to a second edge 101 2 of the central area 101 .

[0140] Figure 7 shows that the connecting flange 10 has four connecting flange sections 10_l, 10_2, 10_3, 10_4, wherein the groove 12 and the fluid sealing element 20 arranged in the groove 12 run straight and continuously in the connecting surface 11 of the connecting flange sections 10_l, 10_2, 10_3, 10_4. Page 24 / 34

[0141] P81144WO

[0142] Reference symbol list

[0143] 1 Underbody protection

[0144] 2 Receiving space (of the underbody protection)

[0145] 10 Connecting flange (of the underbody protection)

[0146] 10_l connecting flange section

[0147] 10_2 Connecting flange section

[0148] 10_3 Connecting flange section

[0149] 10_4 Connecting flange section

[0150] 11 Connecting surface (of the connecting flange)

[0151] 12 Groove (of the connecting flange)

[0152] 13 Material web (of the groove)

[0153] 14 Clearance (of the connecting flange)

[0154] 20 Fluid sealing element

[0155] 30 first reinforcing ribs

[0156] 41 (first) inner rib

[0157] 42 (second) inner rib

[0158] 43 (third) inner rib

[0159] 51 first bend line

[0160] 52 second crease line

[0161] 60 funnels (of the underbody protection)

[0162] 61 Funnel bottom

[0163] 62 Funnel opening

[0164] 70 Reinforcing ring

[0165] 71 first outer edge (of the reinforcing ring)

[0166] 72 second outer edge (of the reinforcing ring)

[0167] 90 screw

[0168] 91 Seal

[0169] 100 sandwich reinforcement elements

[0170] 101 Central area / shell base (of the sandwich reinforcement element)

[0171] 101_l first edge (of the central area)

[0172] 101_2 second border (of the central area)

[0173] 102 Edge area / shell edge (of the sandwich reinforcement element) Page 25 / 34

[0174] P81144WO

[0175] 103 Outer edge (of the sandwich reinforcement element)

[0176] 110 Outer layer (of the sandwich reinforcement element)

[0177] 120 (first) detention mediator layer

[0178] 130 Metal layer (of the sandwich reinforcement element) 131 (First) replacement middle layer (of the sandwich reinforcement element)

[0179] 132 (second) replacement middle layer (of the sandwich reinforcement element)

[0180] 140 (second) adhesion promoter layer 150 inner layer (of the sandwich reinforcement element)

[0181] 151 (first) replacement inner layer (of the sandwich reinforcement element)

[0182] 160 Opening (in the sandwich reinforcement element)

[0183] 161 Opening edge

Claims

Page 26 / 34 P81144WO Patent claims 1. Underbody protection (1) for a motor vehicle, wherein the underbody protection (1) comprises a sandwich reinforcement element (100), the sandwich reinforcement element (100) comprising: a central area (101) and an edge area (102) surrounding it; an outer layer (110) and an inner layer (150), each comprising a plastic, and a metal layer (130); wherein the metal layer (130) is connected to the outer layer (110) by means of a first adhesion promoter layer (120), and wherein the metal layer (130) is connected to the inner layer (150) and is arranged sandwich-like between the outer layer (110) and the inner layer (150), wherein the outer layer (110) has a greater thickness extent than the inner layer (150), and wherein the thickness extent of the outer layer (110) is at least 30% of the total thickness extent of the sandwich reinforcement element (100).

2. Underbody protection (1) according to claim 1, characterized in that the metal layer (130) is connected to the inner layer (150) by means of a second adhesion promoter layer (140).

3. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the outer layer (110) extends to an outer edge (103) bounding the sandwich reinforcement element (100); and the metal layer (130) terminates in front of the outer edge (103) of the sandwich reinforcement element (100). -26- Page 27 / 34 P81144WO 4. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the inner layer (150) terminates before the edge region (102) of the sandwich reinforcement element (100); and the sandwich reinforcement element (100) has a replacement inner layer (151) which adjoins the inner layer (150) and extends into the edge region (102) of the sandwich reinforcement element (100).

5. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the metal layer (130) terminates before the edge region (102) of the sandwich reinforcement element (100); and the sandwich reinforcement element (100) has a substitute middle layer (131) which adjoins the metal layer (130) and extends into the edge region (102) of the sandwich reinforcement element (100).

6. Underbody protection (1) according to one of claims 1 to 4, characterized in that the metal layer (130) extends to the edge region (102) of the sandwich reinforcement element (100).

7. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the sandwich reinforcement element (100) is shell-shaped, wherein the central area (101) has a shell base. (101) and the edge area (102) a bowl edge (102) of the sandwich reinforcement element (100); preferably the underbody protection (1) is designed to accommodate battery cells and / or battery modules. Page 28 / 34 P81144WO 8. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the outer layer (110) has a thickness between 0.5 mm and 3 mm, preferably 2 mm; the metal layer (130) has a thickness between 0.3 mm and 1 mm, preferably 0.6 mm; the inner layer (150) has a thickness between 0.15 mm and 0.7 mm, preferably 0.45 mm; and the first adhesion promoter layer (120) and the second adhesion promoter layer (140) each have a thickness between 0.05 mm and 0.2 mm, preferably 0.1 mm.

9. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the outer layer (110) has a cross-ply with a plurality of fiber layers, wherein at least two directly adjacent fiber layers each have reinforcing fibers whose longitudinal extensions each enclose an angle to each other other than 0°, preferably 90°; the reinforcing fibers of the fiber layer bounding the outer layer (110) outwards are aligned parallel to a longitudinal axis of the underbody protection (1), wherein the longitudinal axis of the underbody protection (1) in the installed state in a motor vehicle is parallel to the direction of travel of the motor vehicle.

10. Underbody protection (1) according to one of the preceding claims, characterized in that the sandwich reinforcement element (100) is at least partially overmolded or overmolded with a thermoplastic material, such that the thermoplastic material is in contact with the edge area Page 29 / 34 P81144WO (102) of the sandwich reinforcement element (100) is connected to the underbody protection (1) by forming a connecting flange (10), preferably by a material bond.

11. Underbody protection (1) according to claim 10, characterized in that a groove (12) for receiving a fluid sealing element (20) is formed in a connecting surface (11) of the connecting flange (10).

12. Underbody protection (1) according to claim 11, characterized in that the sandwich reinforcement element (100) is overmolded or flowed over with the thermoplastic material such that the thermoplastic material is connected to the outer layer (110) in the edge region (102) of the sandwich reinforcement element (100) by forming a plurality of reinforcing ribs (30), preferably by a material bond, so that the reinforcing ribs (30) are arranged on a side of the edge region (102) of the sandwich reinforcement element (100) opposite the connecting surface (11).

13. Underbody protection (1) according to claim 11 or 12, characterized in that the connecting flange (10) has at least one connecting flange section (10_1, 10_2, 10_3, 10_4), preferably four connecting flange sections (10_1, 10_2, 10_3, 10_4), wherein the groove (12) in the connecting surface (11) of this connecting flange section (10_1, 10_2, 10_3, 10_4) runs straight and continuously.

14. Underbody protection (1) according to one of claims 11 to 13, characterized by the following features: in the connecting flange (10) a plurality of connecting devices for driving through one screw each are formed; Page 30 / 34 P81144WO in the connecting surface (11) there are recesses (14) formed through which the respective screws can be driven.

15. Underbody protection (1) according to one of the preceding claims, characterized in that the sandwich reinforcement element (100) is overmolded or overmolded with a thermoplastic material such that the thermoplastic material is connected to the inner layer (150) in the central area (101) of the sandwich reinforcement element (100) by forming a plurality of inner ribs (41, 42, 43), preferably by a material bond.

16. Underbody protection (1) according to claim 15, characterized by the following features: the majority of the inner ribs (41, 42, 43) have first inner ribs (41) and second inner ribs (42); End regions of the first inner ribs (41) define a first kink line (51); and End regions of the second inner ribs (42) define a second fold line (52) which does not coincide with the first fold line (51).

17. Underbody protection (1) according to claim 15 or 16, characterized by the following feature: the majority of the inner ribs (41, 42, 43) has at least a third inner rib (43) extending from a first edge ( 101_1 ) of the central area (101) to a second edge ( 101_2 ) of the central area (101).

18. Underbody protection (1) according to one of the preceding claims, characterized by the following features: the sandwich reinforcement element (100) has at least one opening (160) in the central area (101); -30- Page 31 / 34 P81144WO the sandwich reinforcement element (100) is shaped in the area of ​​the at least one opening (160) such that the sandwich reinforcement element (100) extends in the direction of a receiving space (2) of the underbody protection (1) bounded by the inner layer; the sandwich reinforcement element (100) is overmolded or flowed over with a thermoplastic material in the area of ​​its at least one opening (160) such that the thermoplastic material receives the sandwich reinforcement element (100) at least partially in the area of ​​its at least one opening (160) by forming a funnel (60).

19. Underbody protection (1) according to claim 18, characterized by the following features: the inner layer (150) terminates before an opening edge (161) defining the at least one opening (160) of the sandwich reinforcement element (100); and the sandwich reinforcement element (100) has a replacement inner layer which adjoins the inner layer (150) and extends to the opening edge (161) of the at least one opening (160) of the sandwich reinforcement element (100).

20. Underbody protection (1) according to claim 18 or 19, characterized by the following features: the metal layer (130) terminates before an opening edge (161) defining the at least one opening (160) of the sandwich reinforcement element (100); and the sandwich reinforcement element (100) has a substitute middle layer (132) which adjoins the metal layer (130) and extends to the opening edge (161) of the at least one opening (160) of the sandwich reinforcement element (100). Page 32 / 34 P81144WO 21. Underbody protection (1) according to claim 18, characterized in that the outer layer (110), the metal layer (130) and the inner layer (150) extend to an opening edge (161) that limits the at least one opening (160) of the sandwich reinforcement element (100).

22. Underbody protection (1) according to claims 18 to 21, characterized by the following features: a funnel bottom (61) formed by the thermoplastic material has a first funnel opening (62); the underbody protection (1) has at least one reinforcing ring (70) that limits the funnel opening (62) and is enclosed at its edges by the thermoplastic material; and a wall of the reinforcing ring (70) has an L-shaped geometry in cross-section, wherein a first outer edge (71) of the reinforcing ring (70), which faces away from the funnel bottom (61), has a larger diameter than a second outer edge (72) of the reinforcing ring (70), which faces the funnel bottom (61).

23. Battery housing for receiving battery cells and / or battery modules, comprising a battery housing shell (1) which is designed as underbody protection (1) according to one of claims 1 to 22.

24. Traction battery for a motor vehicle, comprising at least one battery cell and / or at least one battery module and a battery housing according to claim 23, wherein the at least one battery cell and / or the at least one battery module is / are arranged in the battery housing.

25. Motor vehicle, in particular electric motor vehicle - 32 - Page 33 / 34 P81144WO with an underbody protection (1) according to one of claims 1 to 22, which is attached to an underbody of the motor vehicle, in particular to a traction battery of the motor vehicle, or - with a traction battery according to claim 24.

Images