Sandwich composite component for use as a loading floor or parcel shelf of a motor vehicle

Abstract

Sandwich composite component (5) for use as a loading floor (10) or parcel shelf (15) of a motor vehicle (1), comprising a foam core (40), an upper cover layer (55) made of a fiber composite material arranged thereon, and a lower cover layer (65) made of a fiber composite material arranged on the foam core (40), characterized in that the sandwich composite component (5) is designed to absorb a portion of the impact energy occurring in the event of an accident involving the motor vehicle (1) by means of plastic deformation, wherein the upper cover layer (55) and / or the lower cover layer (65), viewed in the longitudinal direction of the loading floor or parcel shelf, each have a unidirectional fiber orientation.

Description

[0001] The present invention relates to a sandwich composite component for use as a loading floor or parcel shelf of a motor vehicle according to independent claims 1 and 2 and to a motor vehicle equipped with such a sandwich composite component according to claim 10.

[0002] DE 103 56 547 A1 discloses a loading floor constructed as a metal sandwich composite component. It has predetermined bending points in discrete areas, allowing it to serve as a crash absorber in the event of an accident. Such a loading floor has the disadvantage of being comparatively heavy.

[0003] DE 10 2013 020 488 A1 discloses a loading floor and a parcel shelf constructed as sandwich composite components, each with a foam core and a surrounding polyurethane foam cover layer. Unfortunately, these can only absorb comparatively low mechanical loads.

[0004] EP 1 359 005 A1 discloses a loading floor and a parcel shelf, which, as sandwich composite components, each have a core layer surrounded by two cover layers. A delamination agent is provided at least partially on the tensile side of such a sandwich composite component. Disadvantageously, the production of these known loading floors and parcel shelves is comparatively complex.

[0005] DE 103 10 368 A1 discloses a loading floor constructed as a sandwich composite component, comprising a foam core, an upper cover layer made of a fiber composite material arranged thereon, and a lower cover layer made of a fiber composite material arranged on the foam core. The known loading floor is said to be lighter than other known loading floors and fulfill its intended function as a comfort-enhancing means.

[0006] It is an object of the present invention to provide a sandwich composite component which can be used as a loading floor or parcel shelf, but which also performs a further function within the motor vehicle as an element which increases the overall rigidity in the event of an accident, which furthermore has a comparatively low weight and which is finally comparatively easy to manufacture.

[0007] This object is achieved by a sandwich composite component for use as a loading floor or parcel shelf of a motor vehicle, which has a foam core, an upper cover layer made of a fiber composite material arranged thereon, and a lower cover layer made of a fiber composite material arranged on the foam core. The sandwich composite component is designed to absorb a portion of the impact energy occurring in the event of an accident-related impact of the motor vehicle through plastic deformation. It is further characterized in that the upper cover layer and / or the lower cover layer each have a substantially unidirectional fiber orientation, viewed in the longitudinal direction of the loading floor or parcel shelf.

[0008] Alternatively, this object is achieved by a sandwich composite component for use as a loading floor or parcel shelf of a motor vehicle, comprising a foam core, an upper cover layer made of a fiber composite material arranged thereon, and a lower cover layer made of a fiber composite material arranged on the foam core. The sandwich composite component is designed to absorb a portion of the impact energy generated in the event of an accident-related impact of the motor vehicle through plastic deformation. This component is characterized in that the upper cover layer has a fiber orientation that is essentially orthogonal to the lower cover layer.

[0009] In addition to its function as a lightweight and comfort-enhancing loading floor or lightweight parcel shelf, the sandwich composite component according to the invention also acts advantageously as a means of improving the safety of vehicle occupants in the event of an accident, which means is particularly easy to manufacture due to its specific structure.

[0010] According to a preferred embodiment, the upper cover layer, the foam core, and / or the lower cover layer are embedded in a single matrix. This advantageously enables a particularly homogeneous bond between the components present in the sandwich composite component. The matrix material can be freely selected and can in particular consist of a thermosetting material, for example an epoxy resin, a polyester, a vinyl ester, or bismaleimide (BMI). Alternatively, the matrix can be formed from an elastomer, preferably polyurethane (PUR).

[0011] Particularly preferably, the upper cover layer, the foam core, and / or the lower cover layer are embedded in a thermoplastic matrix, so that the previously described advantages are supplemented by easier recyclability of the sandwich composite component according to the invention. The thermoplastic matrix can consist in particular of a polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), in particular a PA 6 or PA 6.6, polyethersulfone (PES), polybisphenylsulfone (PSF), polyethyleneimine (PEI), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK).

[0012] As can be seen from the disclosure already presented above, the sandwich composite component according to the invention can advantageously absorb a portion of the impact energy occurring in an impact accident. According to a preferred embodiment, the sandwich composite component is designed to absorb a portion of the impact energy occurring through compression resulting from a plurality of progressive fractures (also called "progressive crushing") and / or interlayer fracture formations (also called "peeling"), since this allows the application of mechanical failure criteria known per se from practice and comparatively easy to calculate and control.

[0013] According to a preferred embodiment, the foam core of the sandwich composite component according to the invention comprises a number of adjacent cells, each of which contains a portion of the matrix. This advantageously makes it particularly easy to adapt the sandwich composite component to various accident-related load cases.

[0014] To improve the recyclability of the sandwich composite component according to the invention, the materials used are purified. For this purpose, the matrix and the foam core are made of polyurethane (PUR).

[0015] The sandwich composite component according to the invention can advantageously be adapted to different load cases by forming the upper cover layer and / or the lower cover layer from a glass fiber material, a carbon fiber material, and / or a composite of glass fiber material and carbon fiber material. Depending on the load cases to be considered, the respective fibers can be formed as short fibers, long fibers, or continuous fibers in one or more layers, wherein the latter can have the same or different orientation angles.

[0016] According to a preferred embodiment, the previously disclosed carbon fiber material is formed from a precursor fiber based on a renewable raw material, preferably lignin, as this further improves the sustainability of the sandwich composite component according to the invention. It should be noted that the precursor fiber can advantageously contain polyacrylonitrile and at least one polymer selected from the group consisting of lignin, lignin derivatives, glucans, cellulose, and any mixtures of two or more of the aforementioned compounds.

[0017] In a preferred embodiment of the sandwich composite component, the upper cover layer additionally has a substantially orthogonal fiber orientation relative to the lower cover layer at those locations where the upper cover layer and / or the lower cover layer, viewed in the longitudinal direction of the loading floor or parcel shelf, each have a unidirectional fiber orientation. This allows the sandwich composite component to be easily adapted for different load cases, for example, for an impact in the vehicle's longitudinal direction or transverse direction.

[0018] The aforementioned object is also achieved by a motor vehicle having the features of the previously disclosed sandwich composite component. The corresponding advantages apply adequately.

[0019] The following is a brief description of figures of the present invention. Fig. 1 is a schematic side view of a motor vehicle according to the invention, which has a loading floor formed with a sandwich composite component according to the invention and a parcel shelf formed with a sandwich composite component according to the invention. Fig. 2 is a schematic, not to scale, sectional view of a part of the Fig. 1 shown parcel shelf. Fig. 3 is a schematic, not to scale, sectional view of a part of the Fig. 2 shown loading floor.

[0020] The following is made with reference to Fig. 1 to 3 provide a detailed, non-prejudicial, particularly limiting, description of embodiments of the present invention. Identical elements are provided with identical reference numerals unless otherwise stated.

[0021] Fig. 1 is a schematic side view of a motor vehicle 1 according to the invention, which has a loading floor 10 formed with a sandwich composite component 5 according to the invention and a parcel shelf 15 formed with a sandwich composite component 5 according to the invention.

[0022] The loading floor 10 is located in the lower area of ​​a trunk 20. The parcel shelf 15 is arranged in the upper area of ​​the trunk 20 below a rear window 25. The trunk 20 is designed to be openable and closable by a trunk lid 30.

[0023] In the exemplary embodiment shown here, the loading floor 10 is designed to be movable out of and back into the trunk 20 by means of guide rails 35. However, this is not mandatory; rather, a fixed loading floor 10 or a loading floor that can be moved or removed in another way can be provided.

[0024] In the exemplary embodiment shown here, both the loading floor 10 and the parcel shelf 15 are each designed as a sandwich composite component 5 and form a structural component of the motor vehicle 1 according to the invention. However, it is also possible to provide either the loading floor 10 or the parcel shelf 15 solely from the sandwich composite component 5 according to the invention. In this case, only one of the components mentioned is designed as a structural component of the motor vehicle 1 according to the invention. Due to their construction with a sandwich composite component 5 according to the invention, the loading floor 10 and the parcel shelf 15 are designed to absorb a portion of the impact energy occurring in the event of an accident-related impact of the motor vehicle 1 through plastic deformation. This means that the loading floor 10 and the parcel shelf 15the parcel shelf 15 may be at least partially destroyed in an accident in which the rear of the motor vehicle 1 is affected by a rear impact and / or side impact.

[0025] In Fig. 2 is the Fig. The parcel shelf 15 shown in Figure 1 is shown in an enlarged sectional view, not to scale. In the exemplary embodiment shown here, the sandwich composite component 5 has a foam core 40 consisting of a number of cells 45 arranged next to one another. Each individual cell 45 is embedded in a matrix 50 consisting of a resin.

[0026] In the Fig. 2 upper area there is an upper cover layer 55, which in this case consists of a fiber composite material with unidirectional carbon fibers 60.

[0027] In the Fig. 2 lower area there is a lower cover layer 65, which according to this embodiment also consists of a fiber composite material with unidirectionally formed carbon fibers 70.

[0028] According to the exemplary embodiment shown here, the carbon fibers 60 and 70 are aligned in the longitudinal direction of the vehicle, ie in the x-direction of a known Cartesian, vehicle-specific coordinate system.

[0029] Both the upper cover layer 55 and the lower cover layer 65 are impregnated with the same resin of the matrix 50 as the foam core 40. Thus, the composite of the upper cover layer 55, foam core 40, lower cover layer 65, and matrix 50 form an intimate bond.

[0030] In Fig. 3 is the Fig. 1 is shown in an enlarged sectional view not to scale. In the exemplary embodiment shown here, the sandwich composite component 5 has a foam core 40 consisting of a number of cells 45 arranged next to one another. Each individual cell is embedded in a matrix 50 consisting of a resin. Thus, the two sandwich composite components 1 for the loading floor 10 and the parcel shelf 50 do not differ in the exemplary embodiment shown here with regard to the foam core 40. However, it should be noted that the loading floor 10 and the parcel shelf 50 can also have different foam cores 40, in particular with different materials and dimensions.

[0031] In the Fig. 3 upper area there is also an upper cover layer 55, which consists of a plurality of unidirectional carbon fibers 60 embedded in the matrix 50. Unlike in the Fig. However, in the embodiment shown in Fig. 2, the carbon fibers 60 are not arranged in the vehicle longitudinal direction, but in the vehicle transverse direction, ie in the y-direction corresponding to the vehicle's own Cartesian coordinate system.

[0032] In the Fig. 3 lower area there is a lower cover layer 65, the structure of which corresponds to the structure of the lower cover layer 65 of the Fig. 2 corresponds to the parcel shelf 15 shown.

[0033] It should be noted that the materials, number, dimensions, and layer structures of the foam cores 40, cells 45, matrix 50, upper cover layers 55, and lower cover layers 65 may differ from one another without deviating from the subject matter of the invention. Furthermore, it is possible to provide each of the lower cover layers 65 or upper cover layers 55 at its end distal from the foam core 40 with a protective layer or lamination layer (not shown here). List of reference symbols 1 motor vehicle 5 Sandwich composite component 10 Loading floor 15 parcel shelf 20 trunk 25 Rear window 30 trunk lid 35 guide rails 40 foam core 45 Cell 50 Matrix 55 upper cover layer 60 carbon fibers 65 lower cover layer 70 carbon fibers x, y, z vehicle's own Cartesian coordinate system

Claims

[1] Sandwich composite component (5) for use as a loading floor (10) or parcel shelf (15) of a motor vehicle (1), which has a foam core (40), an upper cover layer (55) arranged thereon and consisting of a fiber composite material, and a lower cover layer (65) arranged on the foam core (40) and consisting of a fiber composite material, characterized by in that the sandwich composite component (5) is designed to absorb a portion of the impact energy occurring in the event of an accident-related impact of the motor vehicle (1) by means of plastic deformation, wherein the upper cover layer (55) and / or the lower cover layer (65), viewed in the longitudinal direction of the loading floor or the parcel shelf, each have a unidirectional fiber pattern. [2] Sandwich composite component (5) for use as a loading floor (10) or parcel shelf (15) of a motor vehicle (1), which has a foam core (40), an upper cover layer (55) arranged thereon and consisting of a fiber composite material, and a lower cover layer (65) arranged on the foam core (40) and consisting of a fiber composite material, characterized by in that the sandwich composite component (5) is designed to absorb a portion of the impact energy occurring in the event of an accident-related impact of the motor vehicle (1) by means of plastic deformation, the upper cover layer (55) having a fiber orientation that is orthogonal to the lower cover layer (65). [3] Sandwich composite component (5) according to claim 1 or 2, characterized by that the upper cover layer (55), the foam core (40) and / or the lower cover layer (65) are embedded in a matrix (50), preferably in a thermoplastic matrix. [4] Sandwich composite component (5) according to one of the preceding claims, characterized by that it is designed to absorb part of the impact energy that occurs by compression as a result of a large number of progressive fractures and / or interlayer fractures. [5] Sandwich composite component (5) according to claim 3 or according to claim 3 with claim 4, characterized by that the foam core (40) comprises a number of adjacent cells (45), between each of which a part of the matrix (50) is located. [6] Sandwich composite component (5) according to claim 3, according to claim 3 with claim 4, or according to claim 5, characterized by that the matrix (50) and the foam core (40) are formed from a polyurethane. [7] Sandwich composite component (5) according to one of the preceding claims, characterized bythat the upper cover layer (55) and / or the lower cover layer (65) are formed from a glass fiber material, a carbon fiber material and / or a composite of glass fiber material and carbon fiber material. [8] Sandwich composite component (5) according to claim 7, characterized by that the carbon fiber material is formed from a precursor fiber based on a renewable raw material, preferably lignin. [9] Sandwich composite component (5) according to claim 1, 3, 4, 5, 6, 7 or 8, characterized by that the upper cover layer (55) has a fiber orientation that is orthogonal to the lower cover layer (65). [10] Motor vehicle (1), characterized by a sandwich composite component (5) according to one of the preceding claims.

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