DE102022128849A1 - Underbody paneling for a vehicle front or rear - Google Patents

Abstract

An underbody panel (30, 32) for a vehicle rear (26) or a vehicle front (24) of a vehicle (10) has an upper side (52) which, in the assembled state, faces the vehicle (10), a lower side (50) which, in the assembled state, faces away from the vehicle (10), and an integrally designed body (56) with a longitudinal extension (42) and a transverse extension (44). The longitudinal extension (42) is parallel to a longitudinal center plane (40) of the vehicle (10). The transverse extension (44) is transverse to the longitudinal center plane (40) of the vehicle (10). An edge region (58) with at least one connecting element (58) for fastening the underbody panel (30, 32) to the vehicle (10) is integrated into the body (56). An aerodynamically effective structural section (60) is at least partially surrounded by the edge region (58) and provided with a structural bionic pattern (66) and a stiffening structure (68) that overlaps the structural bionic pattern (66) at least in sections. The stiffening structure (68) is formed on the upper side (52). The structural bionic pattern (66) is distributed over the structural section (60) at least on the underside (50). When viewed from the underside (50), the structural bionic pattern (66) has a plurality of concavely shaped structural elements (84) that are distributed over the structural section (60) and fill the structural section (60) on the underside (50).

Description

The present disclosure relates to an underbody panel for a vehicle front or a vehicle rear, in particular to an integrally designed underbody panel produced by injection molding.

Underbody panels for vehicles are examples from the EN 10 2016 120 923 A1 , the EN 10 2017 006 753 A1 , the EN 10 2018 101 950 A1 and the EN 10 2019 124 642 A1 known.

The EN 10 2016 120 923 A1 shows an underbody protection plate with a rib structure, with an additional aerodynamic cover extending over the rib structure. Therefore, several components are required.

From the EN 10 2017 006 753 A1 An underbody panel is known which is made of an EPP material (expanded polypropylene) and has an at least essentially smooth underside. Reinforcing elements in the form of ribs or beads are provided on the upper side.

From the EN 10 2018 101 950 A1 A double-walled underbody panel is known, wherein a first wall has ribs and a second wall covers the first wall and has a smooth aerodynamic surface. The first and second walls can be integrally connected to form an integral structure.

From the EN 10 2019 124 642 A1 An underbody panel is known which comprises at least a sandwich panel in sections, wherein the sandwich panel has two cover layers and a folded honeycomb core arranged between them.

Efficiency (specific energy consumption) is playing an increasingly important role in vehicles. This applies to vehicles powered by combustion engines, but also to electric motors, vehicles with hybrid drives and other types of drives. Aerodynamically designed trim parts can help to increase efficiency, as they have a positive effect on the vehicle's air resistance, at least under certain operating conditions.

This also applies to underbody panels. Another benefit of underbody panels is that they protect the vehicle's components above them from environmental influences. This can at least provide a certain level of protection from splash water, stone chips and the like.

Underbody panels can also have a positive influence on the vibration behavior and noise emissions of the vehicle. In other words, underbody panels can have a sound-dampening effect.

For example, in vehicles with electric motors (battery-electric vehicles, so-called BEVs), there are favorable conditions for the integration of underbody panels for the rear or front of the vehicle. In vehicles powered by combustion engines, the rear is often used to accommodate silencers or other components of the exhaust system. Such components are not required in battery-electric vehicles, so that more favorable application conditions exist for underbody panels made of plastic materials, especially with regard to temperature development.

In principle, it is also conceivable to provide the underbody of the front of the vehicle (the front of the car) with an underbody panel in a similar way.

Especially in connection with electromobility, it is desirable to protect sensitive components of the electric drive from mechanical influences and other environmental influences. This can also be at least supported by underbody paneling.

Irrespective of whether they are used at the front or rear of the vehicle, underbody panels are usually relatively large, as they regularly extend between a first (for example, left from the driver's perspective) and a second (for example, right from the driver's perspective) side of the vehicle. When used as a front-of-the-vehicle underbody panel, it usually covers an area of the underbody - viewed in the direction of travel - in front of a front axle of the vehicle, at least in sections. When used as a rear-of-the-vehicle underbody panel, it usually covers an area of the underbody - viewed in the direction of travel - behind a rear axle of the vehicle, at least in sections.

This results in components with a relatively large surface area and relatively thin walls. The extension in a transverse direction of the vehicle (when viewed from above) is usually greater than the extension in a longitudinal direction of the vehicle (direction of travel when viewed from above). The material thickness of the component is usually (significantly) smaller than the extension in the longitudinal and transverse directions.

The underside of the underbody panel faces the road surface and the top of the vehicle body. Despite their generally flat design, underbody panels are often inclined or curved at least in sections, if only to adapt to a given vehicle design.

Underbody panels can have a positive effect on the efficiency of the vehicle and, where appropriate, on the vibration behaviour or noise emissions of the vehicle.

Nevertheless, the effort required to integrate underbody paneling into a vehicle must be taken into account. This concerns the weight of the component. Furthermore, the desired static and dynamic strength must be guaranteed. Finally, the underbody paneling should be as inexpensive to manufacture as possible.

Against this background, the present disclosure is based on the task of specifying an underbody panel for a vehicle front or a vehicle rear that is designed to be favorable in terms of its own weight and mechanical properties. The underbody panel should be as easy to manufacture as possible. The underbody panel should have a favorable effect on the properties of the vehicle when installed. The underbody panel should have at least sufficient inherent stability. The underbody panel should be designed to be aerodynamically favorable. The underbody panel should be suitable for series production and mass production in the automotive environment.

• - eine Oberseite, die im montierten Zustand dem Fahrzeug zugewandt ist,
• - eine Unterseite, die im montierten Zustand vom Fahrzeug abgewandt ist,
• - einen integral gestalteten Körper mit einer Längserstreckung und einer Quererstreckung, wobei die Längserstreckung parallel zu einer Längsmittelebene des Fahrzeugs ist, und wobei die Quererstreckung quer zur Längsmittelebene des Fahrzeugs ist,
• - einen in den Körper integrierten Randbereich mit zumindest einem Verbindungselement zur Befestigung der Unterbodenverkleidung am Fahrzeug,
• - einen zumindest teilweise vom Randbereich umgebenen, aerodynamisch wirksamen Strukturabschnitt mit einem konstruktionsbionischen Muster und einer das konstruktionsbionische Muster zumindest abschnittsweise überlappenden Versteifungsstruktur, wobei die Versteifungsstruktur auf der Oberseite ausgebildet ist, wobei das konstruktionsbionische Muster zumindest an der Unterseite über den Strukturabschnitt verteilt ist, und wobei das konstruktionsbionische Muster bei Betrachtung der Unterseite eine Mehrzahl konkav geformter Strukturelemente aufweist, die über den Strukturabschnitt verteilt sind und den Strukturabschnitt an der Unterseite ausfüllen.

According to a first aspect, the present disclosure relates to an underbody panel for a vehicle rear or a vehicle front of a vehicle, comprising:

• - an upper side which, when mounted, faces the vehicle,
• - an underside facing away from the vehicle when mounted,
• - an integrally designed body having a longitudinal extension and a transverse extension, wherein the longitudinal extension is parallel to a longitudinal center plane of the vehicle, and wherein the transverse extension is transverse to the longitudinal center plane of the vehicle,
• - an edge area integrated into the body with at least one connecting element for attaching the underbody panel to the vehicle,
• - an aerodynamically effective structural section, at least partially surrounded by the edge region, with a structural bionic pattern and a stiffening structure that overlaps the structural bionic pattern at least in sections, wherein the stiffening structure is formed on the upper side, wherein the structural bionic pattern is distributed over the structural section at least on the underside, and wherein the structural bionic pattern, when viewed from the underside, has a plurality of concavely shaped structural elements that are distributed over the structural section and fill the structural section on the underside.

The task of revelation is solved in this way.

On the one hand, the underbody paneling allows a good compromise between the given strength/rigidity and the required weight or material usage. The underbody paneling can be designed to be relatively thin-walled or lightweight. Nevertheless, any loads that occur can be absorbed and diverted well. In addition, the underbody paneling can be manufactured using conventional manufacturing technology, for example by means of injection molding in a conventional form, for example with an open-close tool.

The structural bionic pattern consists of a plurality or multitude of structural elements combined with one another. In this way, the division of the total surface of the structural section into many individual surfaces results in a favorable force dissipation.

The concave design of the structural elements has a positive effect on air resistance. The term "concave" is used colloquially in the context of the present disclosure. A continuously derivable curvature is not necessarily required. Concave means - when viewed from the underside - a design of the structural elements that is curved inwards towards the top.

The aerodynamically effective structural section has a positive effect on the air resistance when the vehicle is moving, especially when moving forward, at least in certain speed ranges. The concavely shaped structural elements can also be referred to as depressions, dents or dimples. This has a positive effect on the drag coefficient, and the "wind slipperiness" of the vehicle is improved.

Especially in comparison to smooth surfaces, the concavely shaped structural elements ensure that air passing through the underbody paneling is turbulently swirled. This reduces eddy currents behind the underbody paneling (viewed in the direction of travel) and thus reduces overall air resistance.

The integrally designed body is basically made in one piece from a material. However, this does not exclude the possibility that functional elements may be inserted or embedded in some other way, in particular for fastening purposes. These may be rings, eyelets, threads and the like. The body can be designed with thin walls. In exemplary embodiments, the body is shaped like a shell.

Thermoplastics are suitable plastic materials for technical applications. These include, for example, polypropylene (PP), polyamide (PA), polycarbonate (PC), acrylonitrile butadiene styrene plastic (ABS), their derivatives and comparable plastics. The thermoplastic material is usually reinforced with fibers, for example glass fibers, aramid fibers (Kevlar), carbon fibers and the like.

When the vehicle is in operation, stress on the underbody paneling can be caused, for example, by suction caused by air flowing past as the vehicle moves. However, there are also sudden or jerky stresses, for example when the vehicle briefly comes into contact with obstacles or in similar driving situations (e.g. driving off a curb). Additional stress can arise during the journey from stone chips or splashes of water/water spray.

A structural bionic pattern uses construction methods from biology. These are transferred to technical applications. Structural bionic formations with models from the animal and plant world are suitable, which stiffen the structures there and ensure a favorable ratio between weight and strength. Something similar can be achieved with technical components if a suitable structural bionic pattern is used.

Such structures can be transferred to technical conditions that are technically feasible and, above all, manufacturable in accordance with standard design principles. This applies, for example, to certain rib designs for reinforcing inherently fragile structures. It should be noted that, for example, production using plastic injection molding has certain boundary conditions, such as certain minimum wall thicknesses, minimum distances, draft angles, the avoidance of material accumulations and only limited design freedom with regard to the complexity of the tool.

In an exemplary embodiment, the structural bionic pattern is modeled on a turtle shell. Accordingly, the structural elements are modeled on the individual shell plates. In this way, introduced forces can be well absorbed and diverted. In a turtle shell, however, the individual shell plates are usually convex, i.e. curved outwards. In the context of the present disclosure, the structural elements are, on the other hand - viewed from the underside - curved inwards, i.e. concave. This advantageously combines the good strength properties of the turtle shell with the favorable aerodynamic properties of a pattern of depressions (dimples).

For the purposes of the present disclosure, the underbody panel is a potentially self-supporting component that does not necessarily require extensive support. It is therefore not an insert that receives extensive support from other components, particularly in the center of the component.

According to an exemplary embodiment, the structural section is self-supporting in the assembled state. In other words, according to this embodiment, it is not necessary to provide additional support for the structural section, for example by means of fastening elements directly in the structural section. The underbody paneling is attached to the vehicle primarily by means of fastening elements in the edge area. This enables a connection to the body. This is not necessary in the area of the structural section. In this way, the structural section can cover large areas of the components behind it without necessarily being mechanically connected to them.

According to a further exemplary embodiment, the construction bionic pattern comprises similar structural elements, in particular the construction pattern consists of similar (possibly identical) structural elements. This results in a homogeneous design. The structural elements can absorb high loads on their own, and this also applies to the pattern formed from the structural elements.

According to a further exemplary embodiment, the structural elements of the construction bionic pattern are evenly distributed over the structural section. For example, this includes an arrangement of rows and columns that may be slightly offset from one another. In In an exemplary embodiment, the structural elements that form the pattern are of the same type or identical design. This can refer to the basic shape and the size.

In an exemplary embodiment, the structural bionic pattern comprises more than 50 structural elements. In an exemplary embodiment, the structural bionic pattern comprises more than 100 structural elements. In an exemplary embodiment, the structural bionic pattern comprises more than 200 structural elements.

According to another exemplary embodiment, the structural elements are designed like shields. This allows forces and impacts to be absorbed well. It goes without saying that such a structural element is nevertheless curved inwards, so the shield is "turned over" for aerodynamic reasons.

According to a further exemplary embodiment, the structural elements of the construction bionic pattern are modeled on a shield of a turtle shell, in particular a vertebral shield. More generally, the structural elements can be modeled on a horn shield of a turtle shell.

By dividing the total surface into small individual areas, a turtle shell has a favorable force absorption and force dissipation, which has a greater effect the higher the load input. The underbody paneling uses these construction bionics findings in the structural section, but combines them with the concave design to optimize the aerodynamic properties. The vertebral shield of a turtle is a central shield of a turtle shell that protects the spine.

According to another exemplary embodiment, the structural elements each have an at least approximately hexagonal (base) surface. In this way, the structural elements again take up construction bionics findings. Hexagonally designed elements can be designed as a pattern. In particular, the arrangement as a pattern can result in a favorable interlocking, so that forces can be distributed well between "columns" and "rows" of the pattern. It goes without saying that structural elements may be interrupted in the edge area, for example.

According to a further exemplary embodiment, the structural elements each have an at least approximately hexagonal edge, an at least approximately hexagonal center that is offset from the edge, and in particular six connecting surfaces that extend between the edge and the center. This, in turn, does not necessarily apply to structural elements in the edge region.

In this way, the structural elements imitate the basic design of a horn shield, in particular a vertebral shield, a turtle shell. Here too, however, the underbody paneling uses concave structural elements that are curved inwards.

According to another exemplary embodiment, the structural section is parqueted with the structural elements comprising the construction bionic pattern, in particular with a hexagonal grid. In this way, the structural section can be completely and seamlessly filled with the structural elements. This results in a favorable, gap-free and overlap-free covering, so that forces can be absorbed and transmitted well.

According to a further exemplary embodiment, a particularly circumferential stiffening element is arranged between the structural section and the edge region, to which edge-side structural elements in the structural section are coupled. In particular, it is a completely circumferential stiffening element that forms a frame around the structural section. The structural elements can be coupled there. The stiffening element is designed as a rib or bead, for example. The stiffening element ensures good transmission of forces between the structural section and the edge region.

According to a further exemplary embodiment, raised stiffening ribs are formed on the upper side, which extend at least partially completely over the structural section. In this way, the underbody paneling can be further stiffened on the upper side without this having an effect on the aerodynamic properties that are characterized by the underside. In exemplary embodiments, additional stiffening ribs on the underside are deliberately omitted.

According to a further exemplary embodiment, a plurality of stiffening ribs are formed, the main direction of extension of which is parallel to the longitudinal extension. This refers to the longitudinal extension of the vehicle, i.e. possibly to a narrow side of the underbody paneling.

According to a further exemplary embodiment, at least one stiffening rib is formed, the main direction of extension of which is parallel to the transverse extension. This refers to the transverse extension of the vehicle, i.e. possibly to a long side of the underbody paneling.

According to a further exemplary embodiment, at least one stiffening rib with a curved extension is formed, which extends over the structural section and couples two sections of the edge region to one another. In this way, sections of the edge region that are spaced apart from one another can be connected to one another via the stiffening rib, which is additionally guided between these two sections of the edge region along the structural section.

According to another exemplary embodiment, the integrally designed body is produced by means of injection molding with an open-close tool. This is made possible by the fact that the integrally designed body is designed to be suitable for production. For example, an open-close tool can be used without additional slides. This is made possible by a geometry that is sufficiently simple from a production point of view.

According to a further exemplary embodiment, the integrally designed body is formed from a fiber-reinforced thermoplastic material that can be processed by injection molding, wherein the body has, at least in sections, a porous internal structure that is produced by foaming the thermoplastic material.

Foaming can increase the stiffness and strength of the component. The density inside the component can be reduced. Dimensional stability can be increased. Sink marks and similar process-related effects with adverse effects on component quality can be reduced.

The production of the at least partially foamed component from a thermoplastic material can be referred to as thermoplastic foam injection molding. The foaming can take place as chemical foaming or physical foaming. Thermoplastic foam injection molding can lead to a significant reduction in weight. In an exemplary embodiment, a reduction in weight of at least 10% can be achieved compared to a body with a non-porous design. In an exemplary embodiment, a reduction in weight of at least 20% can be achieved.

During physical foaming, a gas (e.g. carbon dioxide or nitrogen) is deliberately introduced into the melt. During processing, the plastic and gas are mixed, with the aim of achieving a solid, non-porous (i.e. compact) edge area and a gradual reduction in density (through embedded bubbles) in the core. In the finished component, there are gas-filled cells of a certain size and distribution, which displace or replace a certain volume of plastic. This results in potential weight savings.

In chemical foaming, the material is provided with a blowing agent. The blowing agent is designed to release a gas for foaming, such as nitrogen or carbon dioxide, in the melting temperature range used.

According to a further exemplary embodiment, the integrally designed body has a density reduced by means of negative embossing. In particular, the negative embossing can be combined with foaming to produce a porous internal structure.

So-called negative embossing involves a defined opening stroke in the tool while the component solidifies. Edge areas are usually already solidified. The core, which is at least partially porous due to foaming, can be expanded further by negative embossing, so that the density in the core can be further reduced.

The foaming of the material can be supported by a targeted opening of the tool by a defined, small opening stroke before the final cooling. This so-called negative embossing is carried out on the basis of a (small) initial wall thickness and can include a stroke in the range of a few tenths of a millimeter to a few millimeters, without any additional suction of material.

The volume made available to the injected material increases accordingly. As a result, the core of the structural component in particular becomes even more porous. The cells in the component formed by the gas expand accordingly. The aim is still to create a sufficiently fine-cell foam structure with a compact edge layer.

The structural strength of the component can be further increased. This means that an even lower weight can be achieved overall under a defined load. The component takes on a sandwich character without the need for a composite construction made of several materials.

According to a further aspect, the present disclosure relates to a vehicle with a chassis, a body and an underbody panel designed according to at least one of the embodiments described herein. In particular, the underbody panel can serve as an underbody panel in the rear area or in the front area of the vehicle.

It is understood that the features mentioned above and those to be explained below can be used not only in the combination specified in each case, but also in other combinations or on their own, without departing from the scope of the present disclosure.

• 1: eine vereinfachte Seitenansicht eines Fahrzeugs;
• 2: eine Draufsicht des Fahrzeugs gemäß 1;
• 3: eine perspektivische Ansicht einer Ausführungsform einer Unterbodenverkleidung von einer Unterseite her;
• 4: eine weitere perspektivische Ansicht der Unterbodenverkleidung gemäß 3 von einer Oberseite her;
• 5: eine vereinfachte Ansicht der Unterbodenverkleidung gemäß den 3 und 4, von unten;
• 6: eine Teilansicht der Unterbodenverkleidung gemäß den 3 und 4, von unten;
• 7: eine mit 6 korrespondierende Teilansicht von oben;
• 8: eine Detailansicht auf Basis der Ansicht gemäß 6 zur Veranschaulichung eines Strukturelements mit hexagonaler Gestaltung;
• 9: eine perspektivische, geschnittene Teilansicht der Unterbodenverkleidung gemäß den 6 und 7, wobei die Schnittebene der Mittenebene in den 6 und 7 entspricht; und
• 10 eine Detailansicht auf Basis der Anordnung gemäß 9 zur Veranschaulichung der konkaven Form eines Strukturelements.

Further features and advantages of the disclosure will become apparent from the following description and explanation of several exemplary embodiments with reference to the drawings.

• 1 : a simplified side view of a vehicle;
• 2 : a plan view of the vehicle according to 1 ;
• 3 : a perspective view of an embodiment of an underbody panel from a bottom side;
• 4 : another perspective view of the underbody paneling according to 3 from an upper side;
• 5 : a simplified view of the underbody paneling according to the 3 and 4 , from underneath;
• 6 : a partial view of the underbody paneling according to the 3 and 4 , from underneath;
• 7 : one with 6 corresponding partial view from above;
• 8th : a detailed view based on the view according to 6 to illustrate a structural element with a hexagonal design;
• 9 : a perspective, cutaway partial view of the underbody paneling according to the 6 and 7 , where the cutting plane of the center plane in the 6 and 7 corresponds; and
• 10 a detailed view based on the arrangement according to 9 to illustrate the concave shape of a structural element.

1 and 2 illustrate a vehicle designated overall by 10. The vehicle 10 has a body 12 and a chassis 14. The vehicle 10 can drive along a road 16 via the chassis 14. The vehicle has an at least partially covered underbody 20 which faces the ground or the road 16.

The vehicle 10 typically has a vehicle front 24 and a vehicle rear 26, which are fixed in relation to a direction of travel 28 (for forward travel). In the vehicle front 24, the underbody 20 has an underbody panel 30. In the vehicle rear 26, the underbody 20 has an underbody panel 32. The underbody panel 30 can also be referred to as front floor panel. The underbody panel 32 can also be referred to as rear floor panel.

In 1 a plane designated 36 describes a conceivable (average) inclination of the underbody panel 30 relative to the road 16 or the direction of travel. Similarly, a plane designated 38 describes a conceivable (average) inclination of the underbody panel 32 relative to the road 16 or the direction of travel. The plane 36 forms a horizontal V with the road 16 that is open in the direction of travel. The plane 38 forms a horizontal V with the road 16 that is open against the direction of travel. It goes without saying that other inclinations or even a horizontal orientation of the underbody panels 30, 32 are also conceivable.

2 illustrates a plan view of the vehicle 10 according to 1 . A longitudinal median plane of the vehicle is designated 40. The longitudinal median plane 40 is perpendicular to the viewing plane in 2 . The longitudinal center plane 40 is parallel to the view plane in 1 . A longitudinal extension 42 of the vehicle 10 is defined along the longitudinal center plane 40. A transverse extension 44 of the vehicle 10 is defined transversely to the longitudinal extension 42 or to the longitudinal center plane 40.

In the following, the terms longitudinal extension 42 and transverse extension 44, which are defined at the level of the vehicle 10, are used equally to describe the dimensions of the underbody panels 30, 32.

The 3 and 4 show, using perspective views, an exemplary design of an underbody panel 32. 3 shows a view from below. 4 shows a view from above. The arrows 42 for the longitudinal extension and 44 for the transverse extension show the basic orientation of the underbody panel 32 when arranged on the vehicle 10, see also 1 and 2 In the embodiment, the narrow side of the underbody panel 32 extends along the longitudinal extension 42. The long side extends along the Transverse extension 44. The proportions of the vehicle 10 are decisive here.

The underbody panel 32 comprises a body 56, which is in particular designed integrally. The body 56 is usually made of a suitable plastic material, in particular of a thermoplastic that can be processed by means of injection molding. Reinforcement in the form of glass fibers or other fibers is usually provided. In addition, fastening elements (rings, eyelets, threads) can be embedded or inserted if required.

The body 56 is designed as a whole similar to a bowl or a tray. The longitudinal extension 42 and the transverse extension 44 define a plane. Perpendicular to this plane there is a height extension, which is only small in the case of the subfloor distribution 32. The 3 visible side is the bottom 50. The 4 The visible side is the top side 52. The bottom side 50 faces the road 16 in the assembled state. The top side 52 faces the vehicle 10 in the assembled state.

The underbody panel 32 comprises an edge region 58 which surrounds a structural section 60. Connecting elements 64 are formed in the edge region 58, for example in the form of suitable fastening holes. In this way, the underbody panel 32 can be fastened to the body 12 or the underbody 20 of the vehicle 10. In the embodiment according to the 3 and 4 the structural section 60 is completely surrounded by the edge region 58. The structural section 60 has a construction bionic pattern 66.

A comparison of the 3 and 4 shows that the pattern 66 on the underside 50 is not obstructed by other elements in the embodiment. The pattern 66 completely fills the structural section 60 on the underside 50. In contrast, 4 a design in which the pattern 66 of the structural section 60 is clearly visible on the upper side 52. However, the pattern 66 is overlaid by a stiffening structure 68. The stiffening structure 68 comprises raised stiffening ribs 70, 72, 74, 76 which are arranged and formed on the upper side 52 of the underbody panel 32. The stiffening ribs 70, 72, 74, 76 are, like the structural section 60, an integral part of the body 56.

The stiffening ribs 70 extend substantially parallel to the transverse extension 44. The stiffening ribs 70 extend over the structural section 60 between two spaced-apart narrow sides of the edge region 58. The stiffening ribs 72 extend substantially parallel to the longitudinal extension 42. The stiffening ribs 72 extend over the structural section 60. In the exemplary embodiment, the stiffening ribs 72 are connected to the edge region 58 on at least one side of the body 56.

The stiffening ribs 74 have an at least partially curved course. The stiffening ribs 74 extend over the structural section 60 between two spaced-apart sections of the edge region 58. The stiffening ribs 76 have a radial (star-shaped) orientation and are coupled to the edge region 58 on at least one side.

The stiffening ribs 70, 72, 74, 76 allow a stiffening of the underbody panel 32, wherein in the exemplary embodiment the exclusive arrangement on the upper side 52 prevents any effects on aerodynamic properties on the underside 50.

A stiffening element 80 extends between the edge region 58 and the structural section 60 and is designed as a circumferential stiffening element 80. This results in a defined transition between the structural section 60 and the edge region 58. In an exemplary embodiment, the stiffening element 80 runs completely around the structural section 60. Within the stiffening element 80, the structural section 60 is designed to be self-supporting in the exemplary embodiment. No fastening elements or the like are provided there. For the design of the stiffening element 80, see also the sectional view according to the 9 and 10 .

5 illustrates the underside 50 of the underbody panel 52 using a simplified representation. The structural section 60 comprises a construction bionic pattern 66. The pattern 66 is formed from a plurality of structural elements 84, which in the exemplary embodiment form a hexagonal grid 82. The orientation of the hexagonal grid 82 in 5 is merely exemplary in nature. The pattern 66 completely fills the structural section 60. There is a defined boundary between the structural section 60 and the edge region 58, compare also the stiffening element 80.

The design and arrangement of the structural elements 84 in the structural section 60 is described with additional reference to the 6-10 illustrated in more detail. 6 (view from below) and 7 (View from above) each show a (half) partial view of the underbody panel 32. In the embodiment, the underside 50 of the structural section 60 is primarily, in particular Only the structural elements 84 are formed. No structural elements are provided in the edge region 58. On the upper side 52 of the underbody panel 32, the structural section 60 and the edge region 58 are still pronounced and can be clearly distinguished from one another. However, in addition to the structural elements 84, stiffening ribs 70, 72, 74, 76 are provided in the structural section 60, which form a stiffening structure 68.

The already mentioned in connection with 4 The stiffening ribs 70, 72, 74, 76 illustrated extend at least in sections over the structural section 60 and the edge region 58 in order to stiffen the underbody panel 32 at the top.

8th shows a detailed view of the 6 highlighted structural element 84. In the exemplary embodiment, the pattern 66 is formed from a plurality of structural elements 84 which are distributed seamlessly over the structural section 60 and are parqueted there.

The structural element 84 has a hexagonal (base) surface 86. The hexagonal shape allows seamless filling of the structural section 60. The hexagonal shape is modeled on a turtle shell. The structural element 84 has a hexagonal edge 90 that surrounds a hexagonal center 92 of the same orientation. Connecting surfaces 94 are formed between the edge 90 and the center 92, for example six connecting surfaces 94, each of which connects a flank of the edge 90 and the center 92. It is understood that in practice, sharp-edged transitions between individual sections of a structural element 84 and between neighboring structural elements 84 are not necessarily to be expected. Instead, the transitions are usually rounded.

9 shows a perspective cut partial view of the underbody panel 32, wherein the cutting plane of the symmetry plane (half plane) according to 6 corresponds. 9 shows the underbody paneling 32 from below. The structural section 60 only includes the stiffening elements 84 on the underside 50. No further elements are provided there. This results in an overall aerodynamically favorable design. 10 shows an enlarged partial view of 9 highlighted structural elements 84. The sectional view shows the curved shape of the structural elements 84, as well as the design of the circumferential stiffening element 80, which extends between the structural section 60 and the edge region 58. The stiffening element 80 is designed as a circumferential collar or shoulder, which merges seamlessly into the edge region 58. This provides a distinctive transition between the structural section 60 and the edge region 58, which additionally stiffens the underbody paneling 32.

It is clear that the stiffening elements 84 are concave, i.e. curved inwards (towards the top side 52). On the underside 50 in the direction of the road, the structural section 60 has a large number of depressions (dimples) which, on the one hand, stiffen the underbody panel 32 and, on the other hand, can have a positive effect on air resistance. 9 and 10 show that the structural elements 84 are, on the one hand, modelled on the shield of a turtle shell, but that on the other hand, with the concave shape, an inverted orientation was deliberately chosen.

10 shows in the sectional view an internal structure 98 of the integrally designed body 56 (compare 3 ), which forms the underbody panel 32. The inner structure 98 is designed to be porous with reduced density at least in sections. This can be achieved, for example, by means of thermoplastic foam injection molding. In addition, it is conceivable to increase the wall thickness of the underbody panel 32 at least in sections by means of negative embossing, without this resulting in additional weight.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions.

Cited patent literature

• DE 102016120923 A1 [0002, 0003]
• DE 102017006753 A1 [0002, 0004]
• DE 102018101950 A1 [0002, 0005]
• DE 102019124642 A1 [0002, 0006]

Claims (17)

Underbody paneling (30, 32) for a vehicle rear (26) or a vehicle front (24) of a vehicle (10), which has the following: - an upper side (52) which, in the assembled state, faces the vehicle (10), - an underside (50) which, in the assembled state, faces away from the vehicle (10), - an integrally designed body (56) with a longitudinal extension (42) and a transverse extension (44), wherein the longitudinal extension (42) is parallel to a longitudinal center plane (40) of the vehicle (10), wherein the transverse extension (44) is transverse to the longitudinal center plane (40) of the vehicle (10), - an edge region (58) integrated into the body (56) with at least one connecting element (58) for fastening the underbody paneling (30, 32) to the vehicle (10), - an aerodynamically effective Structural section (60) with a structural bionic pattern (66) and a stiffening structure (68) that overlaps the structural bionic pattern (66) at least in sections, wherein the stiffening structure (68) is formed on the upper side (52), wherein the structural bionic pattern (66) is distributed over the structural section (60) at least on the lower side (50), and wherein the structural bionic pattern (66), when viewed from the lower side (50), has a plurality of concavely shaped structural elements (84) that are distributed over the structural section (60) and fill the structural section (60) on the lower side (50). Underbody paneling (30, 32) after Claim 1 , wherein the structural portion (60) is self-supporting in the assembled state. Underbody paneling (30, 32) after Claim 1 or 2 , wherein the construction bionic pattern (66) comprises similar structural elements (84) and in particular consists of similar structural elements (84). Underbody paneling (30, 32) according to one of the Claims 1 - 3 , wherein the structural elements (84) of the construction bionic pattern (66) are evenly distributed over the structural section (60). Underbody paneling (30, 32) according to one of the Claims 1 - 4 , wherein the structural elements (84) are designed like shields. Underbody paneling (30, 32) according to one of the Claims 1 - 5 , wherein the structural elements (84) of the construction bionic pattern (66) are modeled on a shield of a turtle shell, in particular a vertebral shield. Underbody paneling (30, 32) according to one of the Claims 1 - 6 , wherein the structural elements (84) each have an at least approximately hexagonal surface (86). Underbody paneling (30, 32) according to one of the Claims 1 - 7 , wherein the structural elements (84) each have an at least approximately hexagonal edge (90), an at least approximately hexagonal center (92) which is offset from the edge, and in particular six connecting surfaces (94) which extend between the edge (90) and the center (92). Underbody paneling (30, 32) according to one of the Claims 1 - 8th , wherein the structural section (60) is parqueted with the structural elements (84) comprising the construction bionic pattern (66), in particular with a hexagonal grid (82). Underbody paneling (30, 32) according to one of the Claims 1 - 9 , wherein a particularly circumferential stiffening element (80) is arranged between the structural section (60) and the edge region (58), to which edge-side structural elements (84) in the structural section (60) are coupled. Underbody paneling (30, 32) according to one of the Claims 1 - 10 , wherein raised stiffening ribs (70, 72, 74, 76) are formed on the upper side (52), which extend at least partially completely over the structural section (60). Underbody paneling (30, 32) after Claim 11 , wherein a plurality of stiffening ribs (72) are formed, the main extension direction of which is parallel to the longitudinal extension (42). Underbody paneling (30, 32) after Claim 11 or 12 , wherein at least one stiffening rib (70) is formed whose main extension direction is parallel to the transverse extension. Underbody paneling (30, 32) according to one of the Claims 11 - 13 , wherein at least one stiffening rib (74) is formed with a curved extension, which extends over the structural section (60) and couples two sections of the edge region (58) to one another. Underbody paneling (30, 32) according to one of the Claims 1 - 14 , whereby the integrally designed Body (56) is produced by injection molding with an open-close tool. Underbody paneling (30, 32) according to one of the Claims 1 - 15 , wherein the integrally designed body (56) is formed from a fiber-reinforced thermoplastic material that can be processed by injection molding, and at least in sections has a porous inner structure (98) which is produced by foaming the thermoplastic material. Underbody paneling (30, 32) according to one of the Claims 1 - 16 , wherein the integrally formed body (56) has a density reduced by means of negative embossing.

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