Energy absorption device of a motor vehicle and motor vehicle with at least one such energy absorption device

Abstract

Energy absorption device of a motor vehicle, comprising a cross member (2) and at least one deformation component (3) fastened thereto and designed as a hollow profile, wherein the deformation component (3) is a one-piece extrusion component and has a front wall (4), a rear wall (5) lying against the cross member (2), two side walls (6, 7) connecting these and at least two chambers (9, 9a, 9b, 10, 10a) formed by a partition wall (8, 8a), which chambers (9, 9a, 9b, 10, 10a) are open on two sides.

Description

[0001] The invention relates to an energy absorption device of a motor vehicle, comprising a cross member and at least one deformation component fastened thereto and designed as a hollow profile.

[0002] To protect the occupants of a motor vehicle in the event of a collision, energy absorption devices are provided on the vehicle as part of a crash management system, through which the energy introduced by the collision is to be reduced or destroyed to a certain extent through a defined deformation on the part of the energy absorption device. Such an energy absorption device usually has at least one so-called crash box, which is usually formed from an extruded metal profile with one or more cavities running along the profile. The elongated metal profile is attached to a cross member of the body on the one hand, and is connected to a body component such as a longitudinal member of the body on the other. The elongated metal profile runs virtually perpendicular to the cross member, i.e.that the cavities also run perpendicular to the cross member and are closed on the one hand by the cross member and on the other hand by the corresponding connection to the longitudinal member. The cross member itself is also a metal hollow profile. In the event of a collision in the front or rear area, the energy input caused by the collision causes deformation of the metal profile and the cross member, although the deformation kinematics of the two components are different. While the elongated metal profile, i.e. the crash box, is axially compressed because the axial force component of the collision force runs in the longitudinal direction of the metal profile, the cross member is crushed because the axial force component runs perpendicular to the longitudinal direction of the cross member and thus its hollow chamber. This means that the deformation behavior of this energy absorption device is homogeneous.

[0003] A differently designed energy absorption device is known from WO 2020 / 234252 A1. This energy absorption device comprises a front and a rear plate, wherein the rear plate is attached to a vehicle structure, while the front plate faces a potential collision opponent. Two buckling plates are arranged between the two plates and are welded to the front and rear plates, respectively. Both buckling plates are connected via a tension-compression means, which causes both buckling plates to deform symmetrically in the event of a collision. The buckling plates have a pre-deformation in the form of a bend, with the bends of both buckling plates pointing in the same direction. If the collision opponent impacts the front plate in the event of a collision, the two buckling plates, coupled via the tension-compression means, buckle symmetrically, thereby dissipating energy.

[0004] The invention is based on the problem of providing an improved energy absorption device.

[0005] To solve the problem, in an energy absorption device of the type mentioned at the outset, the invention provides that the deformation component is a one-piece extrusion component and has a front wall, a rear wall adjacent to the cross member, two side walls connecting these and at least two chambers formed by a partition wall, which chambers are open on two sides.

[0006] According to the invention, the deformation component is an extruded metal hollow profile, for example made of aluminum. This deformation component is arranged in such a way that the two chambers formed by the side walls, the front and rear walls and a partition wall are open on both sides, i.e. they run essentially vertically in the vehicle's vertical direction or horizontally in the vehicle's transverse direction. The deformation component itself is connected to the cross member via the rear wall adjacent to the latter, and in the assembled position is connected in a suitable manner via the front wall, for example to a body component such as a longitudinal member. This arrangement means that the deformation component and the cross member display the same deformation behavior in the event of a collision, as they operate using the same forming principle. This is because both are compressed or expanded in the event of a collision due to the applied load or force.squeezed, so that overall the energy absorption device shows a more homogeneous deformation behavior.

[0007] According to a particularly advantageous development, the rear wall can be extended on one or both sides to form a rear fastening flange for attachment to the cross member. As described, the deformation component is an extruded, hollow metal profile. The at least two chambers are open on both sides. Due to this assembly position, it is possible to design the rear wall to be laterally extended, i.e., to form sections projecting to the side on one or both sides, forming a fastening flange, directly during extrusion, via which fastening flange the connection to the cross member is established. This means that no additional plate or similar fastening elements need to be welded on via a welded joint; rather, the fastening flange can be formed directly from a single material during extrusion of the hollow profile.

[0008] Additionally or alternatively, the front wall can also be extended on one or both sides, forming a front-side mounting flange for attachment to a body component. As with the rear wall, a laterally projecting section can also be molded directly onto the front wall during extrusion, forming a front-side mounting flange. Consequently, an additional attachment of a plate or the like is not required on this side either.

[0009] Preferably, of course, both the rear wall and the front wall have such a fastening flange, via which the actual fastening to the cross member or the body component takes place.

[0010] In the prior art, the deformation component is usually connected to the cross member or the body component via a welded joint. Due to the welding and the associated heat input into the material of the cross member, a heat-affected zone is formed in which the material of the cross member is influenced by temperature, which can have a negative impact on the mechanical properties such as strength. In the event of a collision, a tear can occur in this area, similar to the case of a welded connection to a plate or the like attached to the front. This can be counteracted according to the invention by connecting the front fastening flange to the cross member via screw connections and / or by connecting the rear fastening flange to the body component via screw connections.The fastening flange(s) are therefore screw-on flanges, via which the deformation component is connected to the cross member or body component using suitable screw connections. Welded joints are therefore completely eliminated in this area, as neither the deformation component nor the connection between the deformation component and the cross member or body component has a welded joint. Consequently, there is no adverse heat input at any point that could negatively impact the mechanical properties of the cross member or body component, or the connection itself.

[0011] It is also conceivable for one or both side walls and / or a partition wall to have one or more areas of varying wall thickness. Defined areas can be formed over these areas, where deformation begins preferentially in the event of a collision. These areas of varying wall thickness can easily be incorporated during the extrusion process by designing the extrusion tool accordingly. Such an area can be designed, for example, as a bead or a groove, i.e., as a local material weakening.

[0012] Another possible variation is to have the two side walls with different wall thicknesses and / or the partition wall with a different wall thickness than the side walls. This means that the required deformation behavior can also be adjusted or influenced by varying the wall thicknesses. This wall thickness variation can also be easily created during extrusion.

[0013] In the simplest embodiment of the invention, only one partition wall is provided, thus creating two separate chambers. However, it is also conceivable to provide two or more partition walls to form more than two chambers. This means that a multi-chamber profile is formed that has a larger number of chambers, whereby the chambers can be of the same size or different sizes. The deformation behavior can also be specifically influenced by the arrangement of the partition walls and the specific chamber shapes and sizes.

[0014] One or more partition walls can extend from one side wall to another or from the front wall to the rear wall. The partition walls all run parallel, so that the two or more chambers are all formed in the same way. It is also conceivable, however, for the multiple partition walls to extend between the side walls, the rear wall and the front wall, as well as between the partition walls. This design allows the formation of a multi-chamber profile with any number of chambers arranged lengthwise and crosswise, which, of course, all run parallel in one direction. The partition walls can run perpendicular to one another, but also at a different angle, so that the cross-sections of the chambers can also be varied.

[0015] The energy-absorbing device has at least one deformation component. Typically, two deformation components are provided, offset to the sides, in the front and rear areas of the motor vehicle.

[0016] In addition to the energy absorption device itself, the invention further relates to a motor vehicle comprising at least one energy absorption device of the type described above.

[0017] Further advantages and details of the present invention will become apparent from the exemplary embodiment described below and from the drawings. Fig. 1 a schematic diagram of an energy absorption device according to the invention with a deformation component of a first embodiment, Fig. 2 a schematic diagram of a deformation component of a second embodiment, Fig. 3 a schematic diagram of a deformation component of a third embodiment, Fig. 4 a schematic diagram of a deformation component of a fourth embodiment, and Fig. 5 a schematic diagram of a motor vehicle according to the invention.

[0018] Fig. 1 shows, in the form of a schematic diagram, an energy dissipation device 1 according to the invention, comprising a cross member 2, which is designed as a hollow profile made of metal, for example aluminum. Also provided is a deformation component 3, which is also made of metal, for example aluminum, and is a one-piece or single-material, hollow extrusion component. It has a front wall 4, a rear wall 5 adjacent to the cross member 1, and two side walls 6, 7 connecting the front and rear walls 4, 5. Furthermore, at least one partition wall 8 is provided, resulting in a hollow channel structure with two chambers 9, 10, which, viewed axially, are arranged one behind the other, since the partition wall 8 extends between the two side walls 6, 7.

[0019] The rear wall 5 is provided with a fastening flange 11 formed by two sections 12, 13 that laterally extend the rear wall 5, meaning that the rear wall 5 extends on both sides of the side walls 6, 7. This fastening flange 11 and the sections 12, 13 are also integrally formed, i.e., formed during the extrusion process, which is possible because they extend in the same direction as the side walls 6, 7 and the partition wall 8.

[0020] Likewise, the front wall 4 is provided with a fastening flange 14, which is also formed by two sections 15, 16, over which the front wall 4 is extended. This fastening flange 14 and the sections 12, 13 are also integrally formed, i.e., also formed during the extrusion process.

[0021] The fastening flanges 11, 14 serve to fasten the deformation component 3 on the one hand to the cross member 2 via the fastening flange 11 and on the other hand to another body component such as a longitudinal member via the fastening flange 14. The fastening is carried out via screw connections 17, 18, which are in Fig. 1. This means that no welded joints are used in this fastening. Consequently, no heat input zones resulting from welding-related heat input form in these fastening areas, which could negatively impact the mechanical properties of the connection. Furthermore, as explained, the deformation component 3 is a one-piece, extruded component on which all walls, sections, etc., are formed during its extrusion. This means that this deformation component 3 also does not have a single welded joint and, consequently, there are no heat input zones there that could impair the mechanical properties.

[0022] How Fig. As shown in Figure 1, the two chambers 9, 10 are open on both sides; in the assembled position, they extend vertically along the vehicle's perimeter. Consequently, all walls and the mounting flanges also extend vertically along the vehicle's perimeter.

[0023] In the event of a collision, the force is introduced, for example, via the front of the vehicle, assuming that this energy absorption device 1 is installed in the area of ​​the front of the vehicle. The force is therefore introduced via the fastening flange 14 into the deformation component 3 and via this into the cross member 2. As a result of this force introduction, the deformation component 3 is crushed, its side walls 6, 7 are crushed together, with the cross member 2 also being crushed accordingly. Both show comparable deformation behavior, which results from the corresponding arrangement and design of the deformation component 3, which, as described, is designed and arranged such that the two chambers 9, 10 are open on both sides and, in the example shown, extend in the vertical direction of the vehicle.

[0024] Fig. Figure 2 shows another possible embodiment of a deformation component 3, wherein identical components are given identical reference numerals, which also applies to the following figures. This one-piece and single-material, extruded deformation component 3 also has a front wall 4, a rear wall 5, two side walls 6, 7, the corresponding fastening flanges 11, 12, and a partition wall 8 extending between the side walls 6, 7, as in the embodiment according to Fig. 1. In addition, a second partition wall 8a is provided here, which extends perpendicular to the first partition wall 8 and essentially runs from the front wall 4 to the rear wall 5. Accordingly, in the example shown, four chambers 9, 9a and 10, 10a are formed, i.e. a multi-chamber structure is formed here via the additional partition wall 8a, whereby in the example shown the four chambers 9, 9a, 10, 10a are all the same size. Instead of integrating just one additional partition wall 8a, it would of course also be conceivable to include a third or even more partition walls, which could, for example, extend between the side walls 6, 7, or even between the front and rear walls 4, 5, so that even more chambers are formed.

[0025] Fig. 4 shows another example of a deformation component 3, which is made in the same way as the deformation component 3 of Fig. 1, which is why reference is made to its description. In contrast, the side walls 6, 7 have a greater thickness than the partition wall 8. Furthermore, the side walls 6, 7, which have a different stiffness behavior than a thinner wall as in the embodiments according to Fig. 1 and Fig. 2, areas of different wall thicknesses are provided, which here are specifically formed by corresponding beads 19, 20. Both the different wall thicknesses and the beads 19, 20 can easily be formed during extrusion by setting up the extrusion tool accordingly; thus, in the case of the beads 19, 20, they do not have to be added subsequently. Of course, the formation of one or more additional partition walls is also possible with this design.

[0026] Fig. 4 finally shows a fourth embodiment of a deformation component 3 according to the invention, comprising the front wall 4, the rear wall 5 as well as the fastening flange 11, 14 and the two side walls 6, 7. Here too, two partition walls 8, 8a are provided, which run parallel in the example shown, so that three chambers 9, 9a, 9b are formed. Here too, both the side walls 6, 7 and the partition walls 8, 8a, which all run parallel here, are provided with beads 21, 21a, 21b and 21c, wherein the beads 21, 21a are directed to the same side, while the beads 21b, 21c are also directed to a common side, but opposite to the beads 21, 21a. The side walls 6, 7 and the partition walls 8, 8a all have the same wall thickness, but could also be varied in wall thickness.

[0027] The examples of various deformation components 3 shown above are merely exemplary and not restrictive.

[0028] Fig. Finally, Figure 5 shows a schematic diagram of a motor vehicle 22 according to the invention, on which a first energy-absorbing device 1 is provided in the region of the vehicle front 23 and a second energy-absorbing device 1 is provided in the region of the vehicle rear 24. The two cross members 2 and the two deformation components 3 are shown as examples, with each deformation component 3 being connected to a body component 25, for example, a connecting component on a longitudinal member or the like. Finally, it should be noted that the or each energy-absorbing device 1 has not just one deformation component 3, but at least two such deformation components 3 distributed over the length of the cross member 2. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 234252 A1

[0003]

Claims

[1] Energy absorption device of a motor vehicle, comprising a cross member (2) and at least one deformation component (3) fastened thereto and designed as a hollow profile, characterized by that the deformation component (3) is a one-piece extrusion component and has a front wall (4), a rear wall (5) adjacent to the cross member (2), two side walls (6, 7) connecting these and at least two chambers (9, 9a, 9b, 10, 10a) formed by a partition wall (8, 8a), which chambers (9, 9a, 9b, 10, 10a) are open on two sides. [2] Energy dissipation device according to claim 1, characterized by that the rear wall (5) is extended on one side or both sides to form a rear fastening flange (11) for fastening to the cross member (2). [3] Energy dissipation device according to claim 1 or 2, characterized bythat the front wall (4) is extended on one side or both sides to form a front fastening flange (14) for fastening to a body component (25). [4] Energy dissipation device according to claim 2 or 3, characterized by that the rear fastening flange (11) is connected to the cross member (2) via screw connections (17), and / or that the front fastening flange (14) is connected to the body component (25) via screw connections (18). [5] Energy dissipation device according to one of the preceding claims, characterized by that one or both side walls (6, 7) and / or a partition wall (8, 8a) have one or more areas of different wall thickness. [6] Energy dissipation device according to claim 5, characterized by that an area is designed as a bead (19, 20, 21, 21a, 21b, 21c) or groove. [7] Energy dissipation device according to one of the preceding claims, characterized by that the two side walls (6, 7) have different wall thicknesses, and / or that the partition wall (8, 8a) has a different wall thickness than the side walls (6, 7). [8] Energy dissipation device according to one of the preceding claims, characterized by that two or more partition walls (8, 8a) are provided to form more than two chambers (9, 9a, 9b, 10, 10a). [9] Energy dissipation device according to one of the preceding claims, characterized by that the one or more partition walls (8, 8a) extend from one side wall (6, 7) to the other side wall (6, 7) or from the rear wall (5) to the front wall (4). [10] Energy dissipation device according to claim 9, characterized by that the plurality of partition walls (8, 8a) extend between the side walls (6, 7), the rear wall (5) and the front wall (4) as well as the partition walls (8, 8a). [11] Motor vehicle comprising at least one energy dissipation device (1) according to one of the preceding claims.

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