Body structure for a vehicle

Abstract

The invention relates to a body structure for a vehicle, comprising at least one rocker panel (1) which is formed as a hollow support extending in the vehicle longitudinal direction (x), in the rocker panel cavity (15) of which a reinforcement element (16) formed as an insert part extends in the vehicle longitudinal direction (x) and acts as reinforcement against a side impact. According to the invention, the reinforcement element (16) is formed of at least two parts, consisting of a first profile part (21) and a second profile part (23). In the event of a side impact, the second profile part (23) acts as a pressure element which deforms the first profile part (21) so as to dissipate impact energy.

Description

[0001] Description Body structure for a vehicle The invention relates to a body structure for a particularly electrically powered vehicle according to the preamble of claim 1. In a generic body structure, an assembly space for the high-voltage battery can be formed which is open towards the bottom of the vehicle in the vertical direction and is delimited at the top of the vehicle by a floor panel part forming the vehicle floor. In addition, the assembly space for the high-voltage battery is delimited in the vehicle longitudinal direction by a front cross member and a rear cross member, while the assembly space is delimited in the vehicle transverse direction by side sills. Each of the side sills is designed as a hollow beam running in the vehicle longitudinal direction. The crash-sensitive high-voltage battery must be protected from damage in the event of a side crash.For this reason, a reinforcing element designed as an insert is arranged in the respective sill cavity. This reinforcing element acts as a side impact reinforcement to protect the high-voltage battery in the event of a side impact. In common practice, the reinforcing element is an elongated aluminum extruded profile with a consistently constant profile cross-section in the vehicle's longitudinal direction. However, the aluminum profile represents a significant cost factor and, due to the necessary use of primary aluminum for extrusion, causes a high CO2 footprint. DE 102020000052 A1 discloses a vehicle sill in which a reinforcing element made of an extruded aluminum profile is arranged in the sill cavity. A wooden strip is arranged in a cavity of the extruded aluminum profile.DE 102005 043698 A1 shows another vehicle sill, in whose sill cavity a structural element made of fiber composite plastic is arranged as a reinforcement element. US 6357822 B1 discloses a longitudinal member arrangement for a vehicle, which has a chassis support and a protective support. The protective support is preferably made of a softer material than the chassis support. The object of the invention is to provide a body structure for a vehicle in which the side crash reinforcement can be manufactured with a simpler design, with reduced component weight, and / or more cost-effectively compared to the prior art while maintaining the same crash performance. This object is achieved by the features of claim 1. Preferred developments of the invention are disclosed in the subclaims.The invention relates to a body structure for a vehicle with at least one sill formed as a hollow beam extending in the vehicle's longitudinal direction. A reinforcing element formed as an insert extends in the sill cavity in the vehicle's longitudinal direction. The reinforcing element acts as a side-crash reinforcement. According to the characterizing part of claim 1, the reinforcing element is formed in at least two parts, consisting of a first profile part and a second profile part. In the event of a side crash, the second profile part acts as a pressure element that deforms the first profile part, dissipating crash energy. Furthermore, the second profile part can also be compressed, dissipating crash energy.In this way, the first profile part and the second profile part can each dissipate crash energy using different energy absorption mechanisms: Overall, this makes it possible to provide high crash absorption with an extremely short intrusion path. In a technical implementation, the first profile part and the second profile part can be made of different materials and / or with different strengths. The materials can be selected to promote or support the energy absorption mechanism of the respective profile part. To further enhance crash performance, crash energy dissipation can also occur through material separation, particularly on the second profile part, for example through crushing or material breakage and / or through machining.Alternatively and / or additionally, crash energy can also be dissipated through friction resulting from relative movement between the two profile parts. In a preferred design variant, the first profile part can be made of aluminum, such as an extruded aluminum profile, while the second profile part can be made of a wood-based material, such as laminated veneer lumber. With such a material combination, the profile parts can be manufactured with very good performance. The use of wood as a material can offset / mitigate the disadvantages of aluminum in terms of price and CO2 footprint. Furthermore, the use of wood as a material creates additional attachment points for other components that can be easily screwed into the wood. As a straight profile, the wooden component of the insert can also be cut from a panel, making it inexpensive to manufacture.A further advantage of wood for the present problem is its compressibility, which enables another energy dissipation mechanism. Compressibility depends essentially on the type of wood used and the manufacturing process of the wood product (e.g., via adhesive content or pre-compression) and is therefore adjustable. The two profile parts of the reinforcing element can be connected in different ways. In a preferred embodiment, the first profile part can be designed so that the second profile part can be connected to the first profile part by clamping and / or via a positive fit. This eliminates the need for further complex joining techniques, such as gluing the profile parts.The design of the profile parts is such that both can be made as straight profile parts, so that continuous production of the profile parts themselves, as well as the joining of the profile parts, can be carried out in a continuous process. To clamp the two profile parts, the first profile part can be realized with a receiving groove into which the second profile part can be pressed. For example, a contact zone of the two profile parts can be designed in such a way that sharp-edged contours create a claw connection between the two profiles. Due to the resulting force and form fit, no further joining technology, such as the use of an adhesive, is necessary from a manufacturing point of view. Alternatively, after the two profile parts have been joined, an additional form fit can be created by forming the first profile part. This is particularly preferred in a continuous process, e.g.by using a pressure roller, so that the joining and forming operations can be carried out directly after the production of the first profile part (e.g. by extrusion or roll profiling). In further embodiments, in addition to force and form locking, other joining technologies can be used between the parts, such as gluing, screwing, riveting, clinching, etc. However, it should be emphasized that a connection based purely on force and form locking has a particularly positive effect on the recyclability of the product, as the materials can be separated again in a post-shredding process without, for example, adhesion or contamination from an adhesive. Wood has the further advantage here that, due to its cellulose content, it can be easily substituted for other materials used in the vehicle using NIR spectroscopy.NIR spectroscopy is state of the art in the sorting of shredder fractions. Furthermore, the adhesive application and the bonding process are not trivial to implement, especially with strand-like, nested components. These production-related premises limit the design freedom for optimal functional design. A preferred concrete embodiment of the invention is described below: The first profile part can have a receiving groove that runs in the vehicle's longitudinal direction and is open to the outside in the vehicle's transverse direction, which is formed with groove side walls that widen in a wedge shape towards the outside of the vehicle. In the assembled state, the second profile part is arranged in the receiving groove of the first profile part. The second profile part is spaced from the groove base of the receiving groove of the first profile part by a free deformation path.This design results in the following crash progression: In the event of a side crash, the second profile part is subjected to a side crash force. The second profile part is thereby driven into the receiving groove of the first profile part as a pressure element. In this way, the free deformation path is at least partially used up. In addition, the groove side walls of the receiving groove of the first profile part are spread upwards and downwards in the vertical direction of the vehicle, thereby dissipating crash energy. The second profile part can be in large-area sliding contact with the groove side walls of the receiving groove of the first profile part in a contact zone. In the event of a side crash, the second profile part can be driven in along the groove side walls of the receiving groove of the first profile part under friction and / or machining and / or deformation. In an assembly process, the second profile part is inserted or pushed into the receiving groove of the first profile part in the transverse direction of the vehicle.pressed in. The second profile part can be held stationary in the receiving groove of the first profile part in different ways. From a manufacturing perspective, it is advantageous if the second profile part is held in the receiving groove of the first profile part by claws. To provide such a claw, the groove side walls of the receiving groove can be formed with a claw structure on their contact surfaces, for example with sharp edges. These penetrate into the material of the second profile part during assembly of the reinforcing element. Alternatively and / or additionally, the groove side walls of the receiving groove can also have cutting edges on their contact surfaces. In the event of a side crash, the second profile part is therefore driven into the receiving groove of the first profile part under machining, which dissipates crash energy.Each of the groove side walls of the receiving groove of the first profile part merges at a transition edge into an end wall pointing outwards in the vehicle transverse direction. A movement stop can preferably be formed on the end wall. This prevents displacement of the second profile part from the receiving groove of the first profile part after assembly of the reinforcing element. With a view to reducing the number of components, it is advantageous if the movement stop is formed from the same material and in one piece on the first profile part. The movement stop can preferably be an edge web that extends the groove side wall outwards in the vehicle transverse direction. After the second profile part has been installed in the receiving groove of the first profile part, a forming process can be carried out in which the edge web is formed in order to engage behind the second profile part as a movement stop.In a preferred embodiment, the first profile part can be a metal extruded profile with a lattice-like internal structure made up of stiffening walls and cavities. In this case, in the event of a side impact, the first profile part undergoes holistic deformation, with deformation forces acting in different directions, such as spreading forces acting in the vehicle's vertical direction and / or compressive forces acting in the vehicle's transverse direction. Furthermore, in the event of a side impact, the lattice-like internal structure can also be deformed, dissipating crash energy. In a further embodiment, the local fragmentation of the second profile part is not used, or only to a reduced extent, for energy absorption. Instead, the resulting fragments / pieces redirect the intrusion forces to areas of the first profile part designed to absorb them, thus allowing optimal use of the available installation space.In a further embodiment, the first profile part of the reinforcing element can consist of roll-formed steel, whereby without the use of complex joining technologies such as welding, essentially only open profile geometries are possible. The second profile part, on the other hand, can consist of a softer metal than the first profile part (e.g. a softer aluminum alloy or magnesium) or of a different wood / natural fiber material (e.g. chipboard, OSB, etc.). Alternatively, the second profile part can be made of a higher-strength material, e.g. steel, instead of a softer material and contain cutting edges. The first profile part would then be made of a softer material, e.g. aluminum, whereby the second profile part would be driven through the first profile part by machining when a load is introduced. Exemplary embodiments of the invention are described below with reference to the attached figures.1 to 10 show different embodiments of the invention. Figure 1 shows a body structure of a two-track vehicle, which is described below to the extent necessary for understanding the invention. Accordingly, the body structure has two lateral sills 1 running in the vehicle longitudinal direction x, of which only one is shown in Figure 1. The sill 1 extends in the vehicle longitudinal direction x between a front A-pillar and a rear C-pillar and delimits side door openings of the vehicle on the floor. A crash-sensitive high-voltage battery 9 is installed in the vehicle floor of the body structure. This is positioned below a floor panel part 10 and extends in the vehicle transverse direction y between the two sills 1. In the vehicle longitudinal direction x, the high-voltage battery 9 extends between a front cross member and a rear cross member.The sill 1 is designed as a hollow beam with a sill cavity 15. This is delimited by an outer sill part 17, located on the outside of the vehicle in the vehicle transverse direction y, and an inner sill part 19, located on the inside of the vehicle. The two sill parts 17, 19 are joined together at an upper flange connection and a lower flange connection. A reinforcing element 16 extends into the sill cavity 15 and acts as a side crash reinforcement, the geometry of which is described later. In Figure 1, the reinforcing element 16 is formed in two parts, consisting of a first profile part 21 and a second profile part 23. The first profile part 21 is an extruded aluminum profile with a lattice-like internal structure 25 comprising stiffening walls 27 and cavities 29. In contrast, the second profile part 23 is made of a solid wood material, such as laminated veneer lumber.The first profile part 21 is formed with a receiving groove 31 running in the vehicle's longitudinal direction x and open towards the outside in the vehicle's transverse direction y, which has groove side walls 33 that widen outwards in a wedge shape. Each of the groove side walls 33 of the receiving groove 31 of the first profile part 21 merges at a transition edge 34 into an end wall 36 of the first profile part 21 that points towards the outside of the vehicle. In the assembled state shown, the second profile part 23 is positioned completely within the receiving groove 31 of the first profile part 21. In addition, the second profile part 23 is spaced from the groove base 35 of the receiving groove 31 by a free deformation space f. In Figure 2, the reinforcing element 16 is shown in an exploded view, in which the second profile part 23 is positioned outside the receiving groove 31 of the first profile part 21 and can be pressed into the receiving groove 31 of the first profile part 21 in an assembly direction M.Sharp edges 39 are formed as a claw structure on the contact surfaces 37 of the groove side walls 33 of the first profile part 21. When the second profile part 23 is installed in the receiving groove 31 of the first profile part 21, the sharp edges 39 penetrate the material of the second profile part 23. In this way, the second profile part 23 is held in place after installation (Figure 3) by claws in the receiving groove 31 of the first profile part 21. Figures 4 to 6 indicate a further embodiment in which the contact surfaces 37 of the groove side walls 33 are smooth, i.e., without a claw structure. In Figures 4 to 6, the second profile part 23 is instead held in the first profile part 21 as follows: Thus, the two groove side walls 33 are each extended in the vehicle transverse direction y towards the outside of the vehicle with an edge web 41 which projects from the end wall 36 by a profile height in the vehicle transverse direction.After the second profile part 23 has been pressed into the receiving groove 31 of the first profile part 21, a forming process (Figure 5) is carried out. During the forming process, the two edge webs 41 are deformed, whereby they project beyond the insertion opening of the receiving groove 31 and engage behind the second profile part 23 as movement stops. In the exemplary embodiment shown in Figures 7 and 8, the groove side walls 33 of the receiving groove 31 of the first profile part 21 are formed with cutting edges 43 in the region of the deformation clearance f. In contrast, the contact surfaces between the groove side walls 33 and the second profile part 23 are designed to be smooth. In addition, Figures 7 and 8 indicate a side crash scenario (for example, pole impact) in which a side crash force F Cacts on both the end wall 36 of the first profile part 21 and on the second profile part 23. As a result, on the one hand, the first profile part 21 is compressed in the vehicle transverse direction y. On the other hand, the wedge-shaped second profile part 23 is driven into the receiving groove 31 of the first profile part 21 as a pressure element, specifically with partial use of the deformation space f and with spreading of the two groove side walls 33 of the receiving groove 31. In addition, the second profile part 23 is machined at the cutting edges 43 of the groove side walls 33 of the first profile part 21 with further crash energy dissipation, as indicated in Figure 8. In the exemplary embodiment shown in Figures 9 and 10, the groove side walls 33 of the receiving groove 31 of the first profile part 21 are completely smooth. In the undeformed state (Figure 9), the first profile part 21 has a transverse dimension y0. As can be seen from Figure 10, the first profile part 21 is deformed in the event of a side impact (F C) by a deformation path Δy down to a block dimension y1. This results in a holistic deformation of the first profile part 21, in which deformation forces act in different directions, such as spreading forces acting in the vehicle's vertical direction z and / or compressive forces acting in the vehicle's transverse direction y. In addition, the stiffening walls 27 of the inner structure 25 of the first profile part 21 also perform deformation work at the illustrated deformation areas 45, by means of which the crash energy is dissipated. A further crash energy dissipation occurs according to Figure 10 through sliding friction (F R ) on the contact surfaces between the second profile part 23 and the groove side walls 33 of the first profile part 21.

[0002] List of reference symbols 1 Sill 9 High-voltage battery 10 Vehicle floor 15 Sill cavity 16 Reinforcing element 17 Sill outer part 19 Sill inner part 21 First profile part 23 Second profile part 25 Internal structure 27 Reinforcing walls 29 Cavities 31 Receiving groove 33 Groove side wall 34 Transition edge 35 Groove base 36 End wall 37 Contact surface 39 Claw structure 41 Edge web 43 Cutting edges 45 Deformation areas Δy Deformation path y0, y1, Transverse dimensions f Deformation clearance F C Side crash force F R Friction M Mounting direction

Claims

Patent claims 1.Body structure for a vehicle, comprising at least one sill (1) designed as a hollow beam running in the vehicle's longitudinal direction (x), in the sill cavity (15) of which a reinforcing element (16) designed as an insert extends in the vehicle's longitudinal direction (x), said reinforcing element acting as a side crash reinforcement, characterized in that the reinforcing element (16) is formed at least in two parts from a first profile part (21) and a second profile part (23), and in that, in the event of a side crash, the second profile part (23) acts as a pressure element that deforms the first profile part (21) while dissipating crash energy, while in particular the second profile part (23) compresses while dissipating crash energy, so that preferably the first profile part (21) and the second profile part (23) each dissipate crash energy by means of different energy absorption mechanisms, thereby providing overall high crash absorption with a short intrusion path.Body structure according to claim 1, characterized in that the first profile part (21) and the second profile part (23) are made of different materials and / or with different strengths, and in particular that the materials are selected such that the energy absorption mechanism of the respective profile part (21, 23) is supported.

3. Body structure according to claim 1 or 2, characterized in that further crash energy dissipation takes place by material separation, in particular on the second profile part (23), for example by crushing or material breakage or by machining, and / or in particular that the first profile part (21) is made of aluminum, while the second profile part (23) is made of wood, and / or that further crash energy dissipation takes place by friction work (F. R) between the two profile parts (21, 23).

4. Body structure according to one of the preceding claims, characterized in that the first profile part (21) has a receiving groove (31) running in the vehicle longitudinal direction (x) and in the vehicle transverse direction (y) open towards the outside of the vehicle with groove side walls (33) widening outwards in a wedge shape, in particular that the second profile part (23) is arranged, in particular clamped, in the receiving groove (31) of the first profile part (21), which preferably has a free Deformation space (f) is spaced from the groove base (35) of the receiving groove (31), and that in the event of a side crash, the second profile part (23) is subjected to a side crash force (F C) can be driven into the receiving groove (31) of the first profile part (21), in particular with at least partial use of the deformation space (f) and / or with spreading of the groove side walls (33) of the receiving groove (31) of the first profile part (21).

5. Body structure according to claim 4, characterized in that the second profile part (23) is in sliding contact with the groove side walls (33) of the receiving groove (31) of the first profile part (21) at a contact zone, and that in particular in the event of a side crash, the second profile part (23) under friction (F R) and / or machining along the groove side walls (33).

6. Body structure according to claim 4 or 5, characterized in that the second profile part (23) is held by claw engagement in the receiving groove (31) of the first profile part (21), and that, in particular to provide the claw engagement, the groove side walls (33) of the receiving groove (31) are formed on their contact surfaces (37) with a claw structure (39), such as sharp edges, which penetrate into the material of the second profile part (23) during assembly of the reinforcing element (16).

7. Body structure according to claim 4, 5 or 6, characterized in that the groove side walls (33) of the receiving groove (31) have cutting edges (43) on their contact surfaces (37), so that in the event of a side impact, the second profile part (23) can be driven into the receiving groove (31) of the first profile part (21) while being machined. 8.Body structure according to one of claims 4 to 7, characterized in that each of the groove side walls (33) of the receiving groove (31) of the first profile part (21) merges at a transition edge (34) into an end wall (36) of the first profile part (21) pointing outwards of the vehicle, and in that a movement stop (41) is formed in particular on the end wall (36), which prevents displacement of the second profile part (23) out of the receiving groove (31) of the first profile part (21).

9. Body structure according to one of the preceding claims, characterized in that the movement stop (41) is an edge web extending the groove side wall (33) outwards of the vehicle in the transverse direction (y) of the vehicle, and in that after the second profile part (23) has been installed in the receiving groove (31) of the first. profile part (21), a forming process is carried out in which the edge web (41) is formed in order to engage behind the second profile part (23).

10. Body structure according to one of the preceding claims, characterized in that the first profile part (21) is a metal extruded profile which has a lattice-like inner structure (25) made of stiffening walls (27) and cavities (29), and that in particular in the event of a side crash in the first profile part (21) a holistic deformation takes place in which deformation forces act in different directions, for example spreading forces acting in the vehicle's vertical direction (z) and / or compressive forces acting in the vehicle's transverse direction (y), and / or that in the event of a side crash the lattice-like inner structure (25) also additionally performs deformation work.

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