Underbody protection for a motor vehicle
Patent Information
- Application Number
- PCT/EP2026/058111
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2025-03-27
- Filing Date
- 2026-03-23
- Publication Date
- 2026-10-01
Smart Images
Figure EP2026058111_01102026_PF_FP_ABST
Abstract
Description
[0001] Page 1 / 27
[0002] Applicant: KAUTEX TEXTRON GmbH & Co. KG
[0003] Our reference number: P81179DE
[0004] March 27, 2025
[0005] Underbody protection for a motor vehicle, battery housing for a traction battery, traction battery for an electrically powered motor vehicle, motor vehicle with a traction battery
[0006] The present invention relates to an underbody protection device for a motor vehicle, in particular for an electrically powered motor vehicle. The present invention further relates to a battery housing for accommodating a plurality of battery components. The present invention further relates to a traction battery for an electrically powered motor vehicle. The present invention further relates to a motor vehicle with a traction battery.
[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 vehicles dynamically strike obstacles. Such underbody protection systems increase the overall vehicle weight. Furthermore, steel underbody protection is more susceptible to corrosion.
[0008] To reduce the problem of the high weight of underbody protection systems described above, it is known from the prior art to provide a floor protection system with a plastic layer and a metal layer. In these multi-part underbody protection systems, a bond between the plastic layer and the metal layer is created by means of an adhesion promoter film or another adhesion promoter. Page 2 / 27
[0009] P81179DE is implemented. The adhesion promoter film is laminated onto the metal layer and chemically bonds to the surface oxide layer of the metal layer. During the process of coating the metal layer with a plastic material, the plastic material also chemically bonds with the adhesion promoter. Thus, a material-bonded connection exists between the plastic layer and the metal layer.
[0010] The reaction mechanism for the material-bonded connection between the plastic layer and the metal layer is reversible. Consequently, a correspondingly designed underbody protection system exhibits reduced long-term stability. Furthermore, a corresponding underbody protection system known from the prior art has the disadvantage that the components of the underbody protection system are very difficult to separate from each other without leaving residue, so that the underbody protection system has reduced recyclability.
[0011] The invention is based on the objective of providing an underbody protection system that has high stiffness and energy absorption capacity while simultaneously being lightweight, offering improved long-term stability and improved recyclability.
[0012] The problems underlying the invention are solved by an underbody protection system with the features of claim 1. Advantageous embodiments are described in the dependent claims.
[0013] More precisely, the problem underlying the invention is solved by an underbody protection for a motor vehicle, wherein the underbody protection comprises a metal layer and at least a first plastic layer. The metal layer has a plurality of undercut elements, which are formed on a first connecting surface of the metal layer and extend from page 3 / 27
[0014] P81179DE protrudes from the first connecting surface. The first connecting surface is at least partially in direct contact with the first plastic layer, the first plastic layer being positively connected to the metal layer by the multiple undercut elements engaging behind it.
[0015] The underbody protection according to the invention exhibits high rigidity and energy absorption capacity. Furthermore, the underbody protection according to the invention exhibits improved long-term stability. This is because separation of the metal layer from the plastic layer is only possible by heating the underbody protection to a temperature above the melting point of the plastic layer, whereby this melting point is above the operating temperature of an underbody protection system. Moreover, the underbody protection according to the invention exhibits improved recyclability, since the metal layer can be removed from the plastic layer essentially without residue if the metal layer is peeled off the plastic layer with considerable force.
[0016] The metal layer preferably comprises aluminum and / or steel. More preferably, the metal layer is made of aluminum and / or steel. The metal layer preferably has a thickness between 0.6 mm and 3 mm.
[0017] The metal layer can also be referred to as a protective element or a protective plate. The metal layer is preferably formed on one of the outer sides of the underbody protection.
[0018] The first plastic layer preferably comprises a thermoplastic material. The thermoplastic material is preferably a matrix material. Preferably, a fiber material is distributed and embedded in the matrix material. The thermoplastic material preferably comprises polypropylene and / or polyamide. Page 4 / 27
[0019] P81179DE
[0020] The first plastic layer preferably comprises a thermosetting plastic. The thermosetting plastic can, for example, comprise a phenolic resin and / or a polyester and / or a vinyl resin. The thermosetting plastic is preferably a matrix material. Preferably, a fiber material is distributed and embedded within the matrix material. The fiber material preferably comprises glass fibers and / or carbon fibers and / or aramid fibers. The fiber material preferably comprises short fibers and / or long fibers and / or continuous fibers. The use of a thermosetting plastic has the advantage that, when flowing over the metal layer, the thermosetting plastic is less viscous than a thermoplastic, so that the undercut elements are better enveloped by the plastic.
[0021] The first plastic layer can also be referred to as a support structure. This first plastic layer can, in turn, be multi-layered. For example, it can consist of a layer of fiber-reinforced plastic (such as an organosheet) which is positively bonded to the metal layer, and another layer, for example, not fiber-reinforced or another fiber-reinforced layer.
[0022] The undercut elements ensure a positive connection between the metal layer and the first plastic layer in such a way that they cannot be separated without damage along a direction parallel to the normal vector of the first connecting surface.
[0023] Preferably, the underbody protection is designed such that the metal layer has at least one first undercut element which is shaped such that the first undercut element prevents displacement of the first plastic layer. Page 5 / 27
[0024] P81179DE counteracts a first shear direction relative to the metal layer, which runs parallel to the first connecting surface. Furthermore, the metal layer has at least one second undercut element, which is shaped such that the second undercut element counteracts a displacement of the first plastic layer relative to the metal layer in a second shear direction, which runs parallel to the first connecting surface. The first shear direction and the second shear direction form an angle other than 0° with each other.
[0025] The specially designed underbody protection exhibits improved stability because the first plastic layer and the metal layer cannot be displaced relative to each other without damaging the underbody protection. Thus, when a force is applied to the underbody protection with a force vector that has a component parallel to the first bonding surface, the differently oriented first and second undercut elements counteract any separation of the first plastic layer from the metal layer. Such a force can be applied to the underbody protection, for example, if a vehicle equipped with this underbody protection bottoms out on a bump in the road while driving.
[0026] The underbody protection can of course also have more than two differently oriented or shaped undercut elements that prevent displacements between the metal layer and the first plastic layer in more than two, preferably in all directions parallel to the first connecting surface of the metal layer.
[0027] Preferably, the underbody protection has a second plastic layer and the metal layer has a plurality of undercut elements which are attached to one of the first connecting surfaces. Page 6 / 27
[0028] P81179DE are formed on the opposite side of the second connecting surface of the metal layer and protrude from the second connecting surface. The metal layer is arranged at least partially in a sandwich-like manner between the first plastic layer and the second plastic layer, wherein the second connecting surface is in direct contact with the second plastic layer at least partially, and wherein the second plastic layer is positively connected to the metal layer by the multiple undercut elements engaging behind it.
[0029] The specially designed underride guard exhibits further improved stability. Furthermore, the specially designed underride guard offers improved long-term stability, as the metal layer is better protected against corrosion caused by, for example, weathering.
[0030] The second plastic layer preferably comprises a thermoplastic material. The thermoplastic material is preferably a matrix material. Preferably, a fiber material is distributed and embedded within the matrix material. The thermoplastic material preferably comprises polypropylene and / or polyamide. The fiber material preferably comprises glass fibers and / or carbon fibers and / or aramid fibers. The fiber material preferably comprises short fibers and / or long fibers and / or continuous fibers. The second plastic layer can, for example, be designed as an organosheet.
[0031] The second plastic layer preferably comprises a thermosetting plastic. The thermosetting plastic can, for example, comprise a phenolic resin and / or a polyester and / or a vinyl resin. The thermosetting plastic is preferably a matrix material. Preferably, a fiber material is distributed and embedded in the matrix material. The fiber material preferably comprises glass fibers and / or carbon fibers and / or aramid fibers. The fiber material has... Page 7 / 27
[0032] P81179DE preferably short fibers and / or long fibers and / or continuous fibers. The use of a thermosetting plastic has the advantage that, when flowing over the metal layer, the thermosetting plastic is less viscous than a thermoplastic plastic, so that the undercut elements are better enveloped by the plastic.
[0033] The undercut elements ensure a positive-locking connection between the metal layer and the second plastic layer in such a way that they cannot be separated along a direction parallel to the normal vector of the second connecting surface.
[0034] Preferably, the underbody protection is designed such that the metal layer has at least one third undercut element, which is shaped in such a way that the third undercut element counteracts a displacement of the second plastic layer relative to the metal layer in a first shear direction, which runs parallel to the second connecting surface. Furthermore, the metal layer has at least one fourth undercut element, which is shaped in such a way that the fourth undercut element counteracts a displacement of the second plastic layer relative to the metal layer in a second shear direction, which runs parallel to the second connecting surface. The first shear direction and the second shear direction form an angle with each other other than 0°.
[0035] The appropriately designed underbody protection exhibits improved stability because the second plastic layer and the metal layer cannot be displaced relative to each other without damaging the underbody protection. Thus, when a force is applied to the underbody protection with a force vector that has a component parallel to the second bonding surface, separation of the second plastic layer from the metal layer is prevented. (Page 8 / 27)
[0036] P81179DE counteracts the oriented third and fourth undercut elements. A corresponding force acting on the underbody protection can occur, for example, if a motor vehicle equipped with underbody protection bottoms out on a raised area of the road while driving.
[0037] The underbody protection can of course also have more than two differently oriented or shaped undercut elements that prevent displacements between the metal layer and the second plastic layer in more than two directions, preferably in all directions parallel to the second connecting surface of the metal layer.
[0038] Preferably, the underbody protection is designed such that at least one undercut element has a hook-shaped cross-sectional geometry.
[0039] A properly designed underbody protection system exhibits high stability and is easy to manufacture. The appropriately designed undercut elements can be easily produced on the first and / or second connecting surface using a cutting tool or machining tool.
[0040] Preferably, the underbody protection is designed such that the at least one undercut element has a continuously convex curved first surface and a continuously concave curved second surface.
[0041] A continuously convex first surface has no concave surface sections, and a continuously concave second surface has no convex surface sections. For example, a hook-shaped undercut feature can have a continuously convexly curved first surface. Page 9 / 27
[0042] P81179DE surface and a continuously concave curved second surface.
[0043] Preferably, the underbody protection is designed such that the at least one undercut element has a base section that protrudes from the first connecting surface or from the second connecting surface, and has a hook section that is angled away from the base section.
[0044] The base section can have flat surfaces. These surfaces would be neither concave nor convex, but flat. The same can apply to the hook section, which, with a corresponding design, would be neither concave nor convex, but flat. However, it is also possible that the base section and / or the hook section have convex and / or concave surfaces or surface sections.
[0045] Preferably, the underbody protection is designed such that the base section forms an angle other than 90° with the first connecting surface or with the second connecting surface.
[0046] A properly designed underbody protection system offers even improved stability.
[0047] Preferably, the underbody protection is designed such that the hook section extends away from the base section in one direction.
[0048] Consequently, the hook section cantilevers out from the base section in one direction. A correspondingly designed underbody protection is particularly easy to manufacture. Page 10 / 27
[0049] P81179DE Further preferably, the underbody protection is designed such that the hook section extends away from the base section in at least two directions.
[0050] A suitably designed underbody protection offers even improved stability, as the positive locking connection between the metal layer and the first plastic layer and / or the second plastic layer is more stable.
[0051] Preferably, the underbody protection is designed such that the undercut elements each have a height extension between 0.2 mm and 2 mm.
[0052] The height extent of the undercut elements is the extent or height of the undercut elements parallel to the normal vector of the first connecting surface or the second connecting surface of the metal layer.
[0053] Preferably, the underbody protection is designed such that undercut elements immediately adjacent to each other have a distance of between 2 mm and 10 mm from each other.
[0054] A suitably designed underbody protection system combines the advantages of easy manufacturing and increased stability.
[0055] Undercut elements that are directly adjacent to each other are undercut elements between which no other undercut elements are arranged.
[0056] Preferably, the underbody protection is designed such that the first plastic layer and / or the second plastic layer comprises a fiber-reinforced plastic which has a fiber material distributed in a plastic matrix material. Page 11 / 27
[0057] P81179DE The appropriately designed underbody protection exhibits further improved stability.
[0058] The first plastic layer and / or the second plastic layer preferably comprises a thermoplastic material. The thermoplastic material is preferably a matrix material. The fiber material is distributed and embedded within the matrix material. The thermoplastic material preferably comprises polypropylene and / or polyamide.
[0059] The first plastic layer and / or the second plastic layer preferably comprises a thermosetting plastic. The thermosetting plastic can, for example, comprise a phenolic resin and / or a polyester and / or a vinyl resin. The thermosetting plastic is preferably a matrix material. The fiber material is distributed and embedded within the matrix material.
[0060] The fiber material preferably consists of glass fibers and / or carbon fibers and / or aramid fibers.
[0061] The fiber material can consist of short fibers with a fiber length of less than 1 mm. Furthermore, the fiber material can additionally or alternatively consist of long fibers with a fiber length between 1 mm and 50 mm. Additionally or alternatively, the fiber material can also consist of continuous fibers.
[0062] Preferably, the underbody protection is designed such that the undercut elements of the metal layer are designed to resemble the hooks of a Velcro fastener.
[0063] The appropriately designed underbody protection exhibits improved stability, as the first plastic layer and / or the second plastic layer is not in contact with the metal layer. Page 12 / 27
[0064] P81179DE can be moved without damaging the underbody protection. Thus, when a force is applied to the underbody protection with a force vector that has a component parallel to the first and / or second connecting surface, the differently oriented undercut elements counteract a separation of the first plastic layer from the metal layer and / or the second plastic layer from the metal layer. Such a force can be applied to the underbody protection, for example, if a vehicle equipped with underbody protection bottoms out on a raised area of the road while driving.
[0065] Preferably, the underbody protection is designed in such a way that the fiber material of the first plastic layer and / or the second plastic layer is engaged by the multitude of undercut elements of the metal layer.
[0066] The appropriately designed underbody protection exhibits improved stability, since the undercut elements allow a force to be transferred from the fiber material to the surrounding plastic material in which the fiber material is embedded, thus improving the transfer of force.
[0067] Especially with appropriate underbody protection, the underbody protection is constructed similarly to a Velcro fastener.
[0068] Preferably, the underbody protection is designed such that the first plastic layer has a plurality of reinforcing ribs extending from an inner surface of the first plastic layer opposite the first bonding surface of the metal layer. Page 13 / 27
[0069] P81179DE The appropriately designed underbody protection exhibits improved stability. The respective reinforcing ribs can have different heights along their respective longitudinal extents.
[0070] Preferably the underbody protection is designed in such a way that it has a flange on the edge, the flange preferably being designed circumferentially.
[0071] Preferably, it is designed as a battery housing component.
[0072] Preferably, the underbody protection is designed in such a way that the battery housing component at least partially limits the receiving volume for accommodating a plurality of battery components.
[0073] A battery component can, for example, be designed as a battery cell. Furthermore, a battery component can also be designed as a battery module.
[0074] The invention further aims to provide a battery housing for accommodating a plurality of battery components, which has high rigidity and energy absorption capacity while simultaneously being lightweight, offering improved long-term stability and improved recyclability.
[0075] These problems underlying the invention are solved by a battery housing with the features of claim 20.
[0076] More precisely, the problems underlying the present invention are solved by a battery housing for accommodating a plurality of battery components, which has an underbody protection as described above. Page 14 / 27
[0077] P81179DE The invention further aims to provide a traction battery for an electrically powered motor vehicle which has high stiffness and energy absorption capacity while having low weight, improved long-term stability and improved recyclability.
[0078] This problem is solved by a traction battery with the features of claim 21. More precisely, the problem is solved by a traction battery for an electrically powered motor vehicle, which has a battery housing as described above.
[0079] Furthermore, the invention is based on the objective of providing a motor vehicle which has improved stability.
[0080] This problem is solved by a motor vehicle with the features of claim 22. More precisely, this problem is solved by a motor vehicle which has a traction battery and / or underbody protection as described above.
[0081] Further advantages, details and features of the invention will become apparent from the exemplary embodiments described below.
[0082] Specifically, they show:
[0083] Figure 1: a cross-section through a schematically represented underbody protection according to a first embodiment;
[0084] Figure 2: a cross-section through a schematically represented underbody protection according to a second embodiment; page 15 / 27
[0085] P81179DE
[0086] Figure 3: a cross-section through a schematically represented undercut element according to a first example;
[0087] Figure 4: a cross-section through a schematically represented undercut element according to a second example; and
[0088] Figure 5: a cross-section through a schematically represented undercut element according to a third example.
[0089] In the following description, identical reference numerals denote identical components or identical features, so that a description given for a 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.
[0090] Figure 1 shows an underbody protection device 1 according to a first embodiment. In the illustrated embodiment, the underbody protection device 1 is designed as a battery housing component 1, more precisely as a battery housing shell 1. The battery housing shell 1 at least partially defines a receiving volume 3 for receiving a plurality of battery components not shown in the figures. Of course, it is also possible that the underbody protection device does not have the functionality of a battery housing component.
[0091] The underbody protection 1 has a flange 2 formed at its edge in the form of a connecting flange 2, by means of which the underbody protection 1 can be attached, for example, to a motor vehicle not shown in the figures or to a vehicle not shown in the figures (page 16 / 27).
[0092] The traction battery housing shown in P81179DE can be attached and connected.
[0093] The underbody protection 1 has a metal layer 10 and a first plastic layer 30. Figure 1 shows that the metal layer 10 has a plurality of undercut elements 20, which are formed on a first connecting surface 11 of the metal layer 10 and protrude from the first connecting surface 11.
[0094] The undercut elements 20 shown in Figure 1 have a hook-shaped cross-sectional geometry. The undercut elements 20 of the metal layer 10 are shaped according to or similar to the hooks of a Velcro fastener. With reference to Figures 3 to 5, other or modified geometries of undercut elements 20 are also discussed further below in the description.
[0095] The first connecting surface 11 is in direct contact with the first plastic layer 30, the first plastic layer 30 being positively connected to the metal layer 10 by the engagement of the plurality of undercut elements 20. The undercut elements 20 ensure a positive connection between the metal layer 10 and the first plastic layer 30 such that they cannot be separated along a direction parallel to the normal vector of the first connecting surface 11.
[0096] Figure 1 further shows that the underbody protection 1 has at least one reinforcing rib 33. For the sake of simplicity, only a single reinforcing rib 33 is shown in Figure 1; however, the underbody protection 1 usually has a plurality of reinforcing ribs 33, which extend away from an inner surface 31 of the first plastic layer 30 opposite the first connecting surface 11 of the metal layer 10. Page 17 / 27
[0097] P81179DE
[0098] Figure 2 shows a cross-section through a schematically represented underbody protection 1 according to a second embodiment. Only a partial area of the underbody protection 1 is shown.
[0099] The metal layer 10 of the underbody protection 1 shown in Figure 2 has at least one first undercut element 20_l, which is shaped such that the first undercut element 20_l counteracts a displacement of the first plastic layer 30 relative to the metal layer 10 in a first shear direction RI, which runs parallel to the first connecting surface 11. The metal layer 10 further has at least one second undercut element 20_2, which is shaped such that the second undercut element 20_2 counteracts a displacement of the first plastic layer 30 relative to the metal layer 10 in a second shear direction R2, which runs parallel to the first connecting surface 11. In the illustrated embodiment, the first shear direction RI and the second shear direction R2 are oriented in opposite directions and thus form an angle of 180° with each other.
[0100] The underbody protection 1 shown in Figure 2 further comprises a second plastic layer 40, which is arranged on an underside of the metal layer 10. Thus, the metal layer 10 is arranged, at least in sections, in a sandwich-like manner between the first plastic layer 30 and the second plastic layer 40.
[0101] The metal layer 10 has a plurality of undercut elements 20, which are formed on a second connecting surface 12 of the metal layer 10 opposite one of the first connecting surfaces 11 and project from the second connecting surface 12. The second connecting surface 12 lies at least partially directly against the second side 18 / 27.
[0102] P81179DE plastic layer 40, wherein the second plastic layer 40 is positively connected to the metal layer 10 by interlocking the plurality of undercut elements 20.
[0103] More precisely, the metal layer 10 has at least one third undercut element 20_3, which is shaped such that the third undercut element 20_3 counteracts a displacement of the second plastic layer 40 relative to the metal layer 10 in a first shear direction RI, which runs parallel to the second connecting surface 12. Furthermore, the metal layer 10 has at least one fourth undercut element 20_4, which is shaped such that the fourth undercut element 20_4 counteracts a displacement of the second plastic layer 40 relative to the metal layer 10 in a second shear direction R2, which runs parallel to the second connecting surface 12. In the illustrated embodiment, the first shear direction RI and the second shear direction R2 are oriented in opposite directions and thus form an angle of 180° with each other.
[0104] Figure 3 shows a cross-section through a schematically represented metal layer 10 according to a first example. The undercut element 20 of the metal layer 10 is hook-shaped and has a continuously convex curved first surface 21 and a continuously concave curved second surface 22.
[0105] In the metal layer 10 schematically depicted in Figure 4, the undercut element 20 has a base section 23 that projects from the first connecting surface 11 or from the second connecting surface 12. Furthermore, the undercut element 20 has a hook section 24 that is angled away from the base section 23 and extends away from the base section 23 in one direction. Page 19 / 27
[0106] P81179DE In the metal layer 10 schematically depicted in Figure 5, the undercut element 20 also has a base section 23 that projects from the first connecting surface 11 or from the second connecting surface 12. Furthermore, the undercut element 20 has a hook section 24 that is angled away from the base section 23 and extends away from the base section 23 in two directions.
[0107] In the metal layers 10 shown in Figures 4 and 5, the base section 23 forms an angle other than 90° with the first connecting surface 11 or with the second connecting surface 12, whereby in Figures 4 and 5 this angle is approximately 60°. Page 20 / 27
[0108] P81179DE Reference numeral list
[0109] 1 Underbody protection / battery housing component 2 Flange / connecting flange
[0110] 3 Recording volume
[0111] 10 Metal layer / outer layer
[0112] 11 First connection surface (of the metal layer) 12 Second connection surface (of the metal layer) 20 Undercut element / hook
[0113] 20_l first undercut element
[0114] 20_2 second undercut element
[0115] 20_3 third undercut element
[0116] 20_4 fourth undercut element
[0117] 21 First surface (of the undercut element) 22 Second surface (of the undercut element) 23 Base section (of the undercut element) 24 Hook section (of the undercut element) 30 First plastic layer / inner layer
[0118] 31 Inner surface (of the first plastic layer) 33 Reinforcing rib (of the plastic layer) 40 Second plastic layer
[0119] RI first thrust direction
[0120] R2 second thrust direction
Claims
Page 21 / 27 Applicant: KAUTEX TEXTRON GmbH & Co. KG Our reference number: P81179DE Patent claims 1. Underbody protection ( 1 ) for a motor vehicle, wherein the underbody protection ( 1 ) comprises a metal layer ( 10 ) and at least a first plastic layer ( 30 ), wherein the underbody protection ( 1 ) has the following features: the metal layer ( 10 ) has a plurality of undercut elements ( 20 ) which are formed on a first connecting surface ( 11 ) of the metal layer ( 10 ) and protrude from the first connecting surface ( 11 ); the first connecting surface ( 11 ) lies at least partially directly against the first plastic layer ( 30 ); and the first plastic layer ( 30 ) is positively connected to the metal layer ( 10 ) by interlocking the multitude of undercut elements ( 20 ).
2. Underbody protection ( 1 ) according to claim 1 , characterized by the following features: the metal layer ( 10 ) has at least one first undercut element ( 20 , 20_l ) which is shaped such that the first undercut element ( 20 , 20_l ) counteracts a displacement of the first plastic layer ( 30 ) relative to the metal layer ( 10 ) in a first shear direction (RI ) which runs parallel to the first connecting surface ( 11 ); The metal layer (10) has at least one second undercut element (20, 20_2) which is shaped such that the second undercut element (20, 20_2) counteracts a displacement of the first plastic layer (30) relative to the metal layer (10) in a second shear direction (R2) which runs parallel to the first connecting surface (11); and page 22 / 27 P81179DE the first shear direction (RI ) and the second shear direction (R2 ) enclose an angle to each other other than 0°.
3. Underbody protection ( 1 ) according to one of the preceding claims, characterized by the following features: the underbody protection ( 1 ) has a second plastic layer (40 ); The metal layer ( 10) has a plurality of undercut elements (20) which are formed on a second connecting surface ( 12 ) of the metal layer ( 10) opposite one of the first connecting surface ( 11 ) and protrude from the second connecting surface ( 12 ); The metal layer ( 10) is arranged at least in sections in a sandwich-like manner between the first plastic layer (30) and the second plastic layer (40); the second connecting surface ( 12 ) lies at least partially directly against the second plastic layer (40); and The second plastic layer (40) is positively connected to the metal layer (10) by interlocking the multitude of undercut elements (20).
4. Underbody protection ( 1 ) according to claim 3, characterized by the following features: The metal layer (10) has at least one third undercut element (20, 20_3) which is shaped such that the third undercut element (20, 20_3) counteracts a displacement of the second plastic layer (40) relative to the metal layer (10) in a first shear direction (RI) which runs parallel to the second connecting surface (12); Page 23 / 27 P81179DE the metal layer ( 10) has at least a fourth undercut element (20, 20_4 ) which is shaped such that the fourth undercut element (20, 20_4 ) counteracts a displacement of the second plastic layer (40) relative to the metal layer ( 10) in a second shear direction (R2 ) which runs parallel to the second connecting surface ( 12 ); and the first shear direction (RI ) and the second shear direction (R2 ) enclose an angle to each other other than 0°.
5. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that at least one undercut element (20) has a hook-shaped cross-sectional geometry .
6. Underbody protection ( 1 ) according to claim 5, characterized in that the at least one undercut element (20) has a continuously convex curved first surface (21 ) and a continuously concave curved second surface (22 ).
7. Underbody protection ( 1 ) according to claim 5 or 6, characterized in that the at least one undercut element (20) has a base section (23) which projects from the first connecting surface ( 11 ) or from the second connecting surface ( 12 ) and a hook section (24 ) formed at an angle from the base section (23 ).
8. Underbody protection (1) according to claim 7, characterized in that the base section (23) forms an angle other than 90° with the first connecting surface (11) or with the second connecting surface (12). Page 24 / 27 P81179DE 9. Underbody protection ( 1 ) according to claim 7 or 8, characterized in that the hook section (24 ) extends away from the base section (23) in one direction.
10. Underbody protection ( 1 ) according to one of claims 7 to 9, characterized in that the hook section (24 ) extends away from the base section (23) in at least two directions .
11. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that the undercut elements (20) each have a height extension between 0.2 mm and 2 mm .
12. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that undercut elements (20) immediately adjacent to each other have a distance between 2 mm and 10 mm from each other.
13. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that the first plastic layer (30) and / or the second plastic layer (40) comprises a fiber-reinforced plastic which has a fiber material distributed in a plastic matrix material .
14. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that the undercut elements (20) of the metal layer ( 10) are designed corresponding to the hooks of a Velcro fastener.
15. Underbody protection ( 1 ) according to claim 13 or 14, characterized in that the fiber material of the first plastic layer (30) and / or the second plastic layer (40) Page 25 / 27 P81179DE is undercut by the multitude of undercut elements (20) of the metal layer (10).
16. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that the first plastic layer (30) has a plurality of reinforcing ribs (33) which extend away from an inner surface (31 ) of the first plastic layer (30) opposite the first connecting surface ( 11 ) of the metal layer ( 10 ).
17. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that the underbody protection ( 1 ) has a flange (2 ) on the edge, wherein the flange (2 ) is preferably formed circumferentially.
18. Underbody protection ( 1 ) according to one of the preceding claims, characterized in that the underbody protection ( 1 ) is designed as a battery housing component ( 1 ).
19. Underbody protection ( 1 ) according to claim 18, characterized in that the battery housing component ( 1 ) at least partially limits a receiving volume (3) for receiving a plurality of battery components .
20. Battery housing for receiving a plurality of battery components, comprising an underbody protection ( 1 ) according to one of the preceding claims .
21. Traction battery for an electrically powered motor vehicle, comprising a battery housing according to the preceding claim. Page 26 / 27 P81179DE 22. Motor vehicle comprising a traction battery according to the preceding claim and / or an underbody protection ( 1 ) according to any one of claims 1 to 19.