Sandwich component and motor vehicle body with such a sandwich component

Abstract

Sandwich component (100) with a substantially rectangular outline and two cover layers (120, 130) and a core structure located therebetween, via which the cover layers (120, 130) are spaced from one another, wherein the edges of the cover layers (120, 130) are combined to form a collar-like and all-round flange-like edge closure (140) and the core structure is inserted at its edge into the edge closure (140), characterized in that the core structure is formed from a shaped inner sheet (110), namely a corrugated sheet with a wave profile or trapezoidal profile, which has grooves formed by the wave profile or trapezoidal profile, wherein the cover layers (120, 130) and the inner sheet (110) form a closed composite, for which purpose the edges of the cover layers (120, 130) are combined to form the collar-like and all-round flange-like edge closure (140) and are joined to this edge closure (140) in such a way that the edge of the inner sheet (110) is inserted into the edge closure (140) in sections only on two opposite sides of the rectangular outline, namely on its two longitudinal sides parallel to the grooves of the corrugated or trapezoidal profile, wherein along the two transverse sides of the inner sheet (110) only a positive fixing of the inner sheet (110) is effected by the combined cover layers (120, 130).

Description

[0001] The invention relates to a sandwich component according to the preamble of patent claim 1. The invention further relates to a motor vehicle body with at least one such sandwich component.

[0002] Sandwich components typically consist of two cover layers and a core structure between them, to which the cover layers are applied and via which the cover layers are spaced from one another. In addition to weight savings (lightweight construction), stiffness and strength can be adjusted to suit the load. Depending on the application, the penetration of liquids and contaminants must be prevented in the edge area. Common edge sealing methods include sealing with adhesives and sealants. Another method is to seal the edge by milling off a cover layer and the core structure and then flanging the remaining cover layer. Furthermore, the edge area is often subject to mechanical stress, which must be taken into account. In addition, due to the large volumes involved, economic aspects such as cost-effective manufacturing processes and short cycle times must also be considered, especially in automotive construction.

[0003] DE 10 2013 002 504 A1 describes a motor vehicle floor structure comprising an upper shell, a lower shell, and a stiffening structure located between them. The stiffening structure can be a corrugated sheet with a wave profile or trapezoidal profile. The individual grooves formed by the wave pattern can be closed on one or both sides with a side wall, whereby the closure of the grooves by the side wall is advantageously integrated into the manufacturing process of the stiffening structure. The floor structure can also have connecting elements designed as separate components, with which it can be connected, for example, to a sill.

[0004] A plate-shaped lightweight component is known from the related EP 1 223 032 A2. The lightweight component consists of two opposing plates, in particular sheets, and an intermediate support structure made of thermoplastic material. The support structure is designed as an egg-crate structure. The plates or sheets are connected to each other in a peripheral edge region.

[0005] Regarding the state of the art, reference is also made to US 2011 / 0061792 A1, DE 10 2013 003 538 A1, DE 697 34 616 T2, DE 102 00 750 A1 and DE 10 2013 010 332 A1.

[0006] The object of the invention is to provide a further laterally closed sandwich component which is light and stable and can be easily manufactured, particularly in medium and large series production.

[0007] This object is achieved by a sandwich component according to the invention in accordance with patent claim 1. The independent patent claim also extends the invention to a motor vehicle body with at least one sandwich component according to the invention. Preferred developments and refinements of the invention are evident for both subject matters of the invention from the dependent patent claims, the following description, and the drawings.

[0008] The sandwich component according to the invention has two cover layers and a core structure located between them, which is formed from a shaped inner sheet, namely a corrugated sheet. The cover layers and the inner sheet form a closed composite, for which purpose the edges or edge zones of the cover layers are combined to form a collar-like, all-round, flange-like edge closure and joined together at this edge closure in such a way that the edge of the inner sheet is partially integrated or inserted into this edge closure, as explained in more detail below.

[0009] The peripheral edge seal has a dual function. On the one hand, it serves as an edge seal and, on the other hand, acts as a joining flange for connecting the sandwich component to other components, e.g., by riveting, gluing, welding, soldering, screwing, and the like, eliminating the need for additional connection parts (such as the aforementioned fasteners).

[0010] According to the invention, the edge sealing is achieved by joining the cover layers at the edges, creating a closed bond. A separate edge sealing, such as with the sidewall or adhesive or sealant sealing described above, is not required, thus eliminating the associated manufacturing or production costs. The cathodic dip coating of open cavities or channels, which is frequently practiced in the prior art and is particularly complex for small cross-sections, can also be eliminated.

[0011] According to the invention, it is further provided that the inner sheet forming the core or core structure is partially integrated or inserted into the edge closure at its edge. Thus, the inner sheet is not integrated into the edge closure at its entire outer edge.

[0012] Rather, the edge seal comprises sections in which the edges of the cover layers (possibly including an adhesive or sealant) lie directly on top of one another and are joined (two-layer or double-layer joint), and sections in which the edges of the cover layers lie indirectly on top of the intermediate edge of the inner panel and are joined, including this edge zone belonging to the inner panel (three-layer joint). The inner panel is therefore not only held between the cover layers (typically, the inner panel is also bonded to the cover layers at the contact points), but is also held by its edge along the relevant sections, resulting in advantageous mechanical properties, such as excellent crash stability.

[0013] The sandwich component according to the invention can also be manufactured easily. Preferred manufacturing methods are described below. The sandwich component according to the invention can, for example, be manufactured in a substantially continuous process, which is particularly advantageous for medium and large-scale production.

[0014] The cover layers can be made of any suitable material. The cover layers are preferably sheet materials (so-called cover sheets), e.g., aluminum and / or steel sheet with a sheet thickness of, for example, 0.6 mm to 2.5 mm, preferably 0.8 mm to 1.2 mm. The same applies to the inner sheet, which is a corrugated sheet with a wave profile (e.g., sine wave, in particular with flattened wave curves) or trapezoidal profile (also with steep, almost vertical flanks). The inner sheet is preferably glued or joined in another suitable manner at the contact points with the cover layers or cover sheets.

[0015] To create the collar-like, circumferential edge finish, the edges or edge zones of the cover layers can be pressed together, forming a flat contact area, or pressed together and joined. The pressing can be done in such a way that only one of the cover layers is deformed at its edge or in its edge zone, or that both cover layers are deformed at their edges or in their edge zones.

[0016] Preferably, the cover layers or their overlapping edges are joined along the peripheral edge closure by means of a material-to-material bond, in particular by gluing, soldering, and / or welding. The joint is preferably designed in such a way that a reliable and age-resistant seal against liquids and contaminants is created.

[0017] The sandwich component according to the invention has (in plan view) a substantially rectangular outline, wherein the inner sheet is inserted into the peripheral edge closure only on two opposite sides of this rectangular outline. On the other two sides, the inner sheet is positively fixed by the cover layers joined together at their edges. As already explained, the inner sheet is a corrugated sheet with a plurality of grooves formed by the corrugation. The integration into the edge closure takes place along the long sides parallel to these grooves, and transversely thereto, only a positive fixing takes place along the two transverse sides, as explained in more detail below.

[0018] The collar-like peripheral edge finish can have a width of 10 mm to 50 mm, and preferably 15 mm to 25 mm. The core structure formed from a formed inner sheet can have a thickness or height of 3 mm to 25 mm. With the above-mentioned cover layer thicknesses, this results in a preferred component thickness or height of approximately 3 mm to approximately 30 mm.

[0019] The sandwich component according to the invention can be manufactured in series in a continuous or quasi-continuous manufacturing process from strip material, in particular sheet metal strips unrolled from a coil. Series production can be carried out without intermediate transport and / or transfer in a suitably designed facility.

[0020] A first procedure includes the processing steps or stages: - forming a first strip material forming the inner sheet; - joining the first formed strip material to a second strip material and a third strip material to produce the cover layers, optionally with the addition of adhesive; - combining the cover layers, whereby a closed bond is created between the inner sheet and the cover layers by forming a collar-like peripheral edge finish, which is achieved in particular by pressing the edge zones together, as described above; - Separating the closed composite from the material or sheet metal strips.

[0021] The edge-to-edge joining of the cover layers along the edge termination can, as explained above, be achieved by gluing, soldering, welding, or the like. The edge-to-edge joining is particularly preferably achieved by creating a circumferential laser weld seam, which can be performed, for example, before, during, or after the separation. It is particularly preferred that both the welding and the separation be performed with the same laser beam device or with the same laser beam, i.e., a separation and joining operation are performed essentially simultaneously.

[0022] A second method differs from the first method according to the invention essentially in that the last steps are carried out in a reverse sequence. Accordingly, the second method comprises the following processing steps or stages: - forming a first strip material forming the inner sheet; - joining the first formed strip material to a second and third strip material to produce the cover layers; - Separating the composite formed by the inner sheet and cover layers from the material or sheet metal strips; - Combining the cover layers or their edges, whereby a closed bond is created between the inner sheet and the cover layers by forming a collar-like peripheral edge finish.

[0023] The invention is explained in more detail below in a non-limiting manner with reference to the drawing. Fig. 1 shows schematically and not to scale a sandwich component according to the invention in a plan view and in two sectional views; and Fig. 2 shows an alternative design variant, analogous to that in Fig. 1c shown sectional view.

[0024] Fig. 1 shows a plan view (according to Fig. 1a) Rectangular sandwich component 100 comprising two sheet metal cover layers or cover sheets 120 / 130 and a core structure between them, which is formed from an inner sheet 110 with a wave-like trapezoidal profile. The flanks of the trapezoidal profile can also be steeper or flatter. The grooves or hollow chambers formed by the wave pattern can define a longitudinal direction L and a transverse direction Q. At the flattened contact points, the inner sheet 110 can be bonded to the cover layers or cover sheets 120 / 130 using adhesive K. The flattened areas can be wider or narrower or even omitted entirely (e.g., in the case of a purely wave-like or triangular profile). The core structure can have a thickness or height h of 3 mm to 25 mm.

[0025] As can be seen from the sectional views (according to Fig. 1b and Fig. As can be seen in Figure 1c), the cover layers or cover sheets 120 / 130 and the inner sheet 110 form a closed composite, for which purpose the edges or edge zones of the cover layers or cover sheets 120 / 130 are combined to form a collar-like peripheral edge finish 140 and are tightly joined along this collar-like or flange-like edge finish 140 by gluing and / or welding (see weld seam 150). The edge finish 140 can be formed circumferentially with different widths b, e.g., from 10 mm to 50 mm.

[0026] A special feature of the metallic sandwich component 100 is that the inner sheet 110 is inserted at its edge or in its edge zone into the circumferential edge closure 140, but only partially or in sections. The inner sheet 110 is inserted into the edge closure 140 only on the two long sides running in the longitudinal direction L, by positioning the respective outer edges of the inner sheet 110 between the combined edges or edge zones of the cover layers or cover sheets 120 / 130 (i.e., virtually clamped) and bonded to the edge closure 140 by gluing and / or welding. This is very well understood in the Fig. 1b shown cross-section, whereby also in the Fig. 1a, the corresponding joining areas are hatched and marked with F. At the transition points x (transition between the double-layer section and the three-layer section), adhesive or sealant, or more adhesive or sealant, can be applied locally to ensure a seal. The edge sections of the inner sheet 110 inserted into the edge seal 140 are also at the same level (see Fig. 1b). On the two transverse sides running in the transverse direction Q, however, the inner sheet 110 is only positively fixed by the combined cover layers or cover sheets 120 / 130. This is very well illustrated in the Fig. 1c shown longitudinal section.

[0027] The sandwich component or sandwich sheet 100 has favorable mechanical properties, such as excellent crash stability, with the at least double-layered edge seal 140, in particular, exhibiting high strength and rigidity, which is advantageous, among other things, for a subsequent joining process. The sandwich component 100 is also easy to manufacture.

[0028] The sandwich component 100 can, for example, be manufactured from three sheet metal strips in an essentially continuous manufacturing process. The sheet metal strips are unrolled from coils (sheet metal strip rolls), whereby the first sheet metal strip for forming the corrugated inner sheet 110 is narrower and has a higher unwinding speed than the sheet metal strips for forming the cover layers or cover sheets 120 / 130. If necessary, the desired strip widths are produced by what is known as slitting the sheet metal strips. After the first sheet metal strip has been formed into the corrugated inner sheet 110 or a corrugated sheet using a suitable device (e.g. using a pair of forming rollers), it is joined to the second and third strip material to produce the cover layers or cover sheets 120 / 130. The collar-like, circumferential edge finish 140 is then produced, for which purpose the edges or edge zones of the cover layers or cover sheets 120 / 130, e.g.by pressing them together using a suitable device, thereby creating a closed composite, and also inserting the inner sheet 110 into the edge seal 140 on its longitudinal sides in the joining areas F, as described above. Only then is the separation from the sheet metal strips carried out by means of a separating cut. An alternative procedure is described above.

[0029] The process steps or stages can be carried out in a suitably designed system. The system can therefore mass-produce sandwich components 100 according to the invention from supplied sheet metal strips. The feed direction is indicated by the arrow DLR. The grooves or hollow chambers of the corrugation pattern in the inner sheet 110 are created perpendicular to the feed direction DLR.

[0030] At the Fig. In the embodiment shown in Figure 1, only the edge or edge zone of a cover layer or cover sheet, namely the lower cover layer or lower cover sheet 130, is deformed to form the edge seal 140, creating a flat contact between the edges or edge zones to be joined. The upper cover layer or upper cover sheet 120 remains undeformed. Fig. 2 shows analogous to the sectional view of the Fig. 1c shows a variant in which the edges or edge zones of both cover layers or cover sheets 120 / 130 are deformed to form the edge finish 140. Due to their spatial shape, the deformed cover layers or cover sheets 120 / 130 can also be referred to as hoods or hood-like cover layers. Fig. The frame profiles shown in Figure 1b are only examples and may vary depending on design and / or process specifications (i.e. flatter or steeper frame profiles). In both variants, the inner sheet 110 is positively fixed in the longitudinal direction L by the cover layers or cover sheets 120 / 130, which are combined or pressed together at their edges, as can be clearly seen from the Fig. 1c and Fig. 2, which has a positive influence on the stability and mechanical properties of the sandwich component 100.

[0031] The sandwich component 100 is, for example, a body component, e.g., a floor panel, which can be connected to at least one other body component at its collar-like peripheral edge 140. The connection can be achieved, for example, by gluing, riveting (especially high-speed riveting), or screwing (especially direct screwing without pre-drilling using FDS screws). An adhesive or sealant can also be used for sealing.

Claims

[1] Sandwich component (100) with a substantially rectangular outline and two cover layers (120, 130) and a core structure located therebetween, via which the cover layers (120, 130) are spaced from one another, wherein the edges of the cover layers (120, 130) are combined to form a collar-like and all-round flange-like edge closure (140) and the core structure is inserted at its edge into the edge closure (140), characterized by , that the core structure is formed from a shaped inner sheet (110), namely a corrugated sheet with a wave profile or trapezoidal profile, which has grooves formed by the wave profile or trapezoidal profile, wherein the cover layers (120, 130) and the inner sheet (110) form a closed composite, for which purpose the edges of the cover layers (120, 130) are combined to form the collar-like and all-round flange-like edge closure (140) and are joined to this edge closure (140) in such a way that the edge of the inner sheet (110) is inserted into the edge closure (140) in sections only on two opposite sides of the rectangular outline, namely on its two longitudinal sides parallel to the grooves of the corrugated or trapezoidal profile, wherein along the two transverse sides of the inner sheet (110) only a positive fixing of the inner sheet (110) is effected by the combined cover layers (120, 130). [2] Sandwich component (100) according to claim 1, characterized by that the cover layers (120, 130) are pressed together flat at their edges, whereby only one cover layer (130) is deformed. [3] Sandwich component (100) according to claim 1, characterized by that the cover layers (120, 130) are pressed together flat at their edges, whereby both cover layers (120, 130) are deformed. [4] Sandwich component (100) according to one of the preceding claims, characterized by that the cover layers (120, 130) are joined along the edge closure (140) by gluing and / or welding. [5] Sandwich component (100) according to one of the preceding claims, characterized by that the edge closure (140) has a width (b) of 10 mm to 50 mm, preferably of 15 mm to 25 mm. [6] Sandwich component (100) according to one of the preceding claims, characterized by that the core structure formed from the inner sheet (110) shaped as a corrugated sheet has a thickness (h) of 3 mm to 25 mm. [7] Motor vehicle body with at least one sandwich component (100) according to one of claims 1 to 6, wherein said component is joined at its edge termination (140) to at least one other body component.

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