BUMPER ARRANGEMENT FOR A MOTOR VEHICLE

Description

[0001] The invention relates to a bumper arrangement for a motor vehicle according to the features in the preamble of claim 1.

[0002] Bumper assemblies are standardly installed on both the front and rear of motor vehicles to absorb the impact energy from collisions and minimize damage to the vehicle's supporting structure. Conventional bumper assemblies feature a cross member that can be secured transversely to the side members of a vehicle frame by incorporating crash boxes. The cross member serves to direct the energy resulting from an impact into the crash boxes, where the impact energy is converted into deformation energy. The system is coordinated so that the crash boxes are positioned as centrally as possible on the side members, and the impact energy is directed via the cross members into the crash boxes and thus onto the side members with the lowest possible bending moment.In most frontal collisions, however, the impact occurs offset and only in a specific area of ​​the front of the vehicle, i.e. not across the entire width.

[0003] EP 3 668 758 B1 discloses a bumper cross member for a vehicle, which is composed of an outer shell and an inner shell connected to the outer shell.

[0004] DE 10 2019 120 327 A1 discloses a bumper cross member for a motor vehicle. It is composed of two shells and has a central passage through which the cross member is divided into an upper hollow chamber section and a lower hollow chamber section. The cross member is supported on the vehicle side by crash boxes. The bumper cross member has a second cross member arranged below the lower hollow chamber section, to which crash boxes are also connected.

[0005] Furthermore, bumper arrangements are known from DE 10 2017 222 081 A1 and DE 20 2020 005 403 U1.

[0006] Motor vehicle bumpers and bumper assemblies must meet legal regulations as well as the pedestrian protection requirements set by consumer protection organizations. Furthermore, the requirements of the various insurers' classification tests (RCAR, GDV) must be met. At the same time, car manufacturers have vehicle-specific requirements for optimal use of installation space, high energy absorption capacity with the lowest possible weight, acceptable costs, and easy installation. Implementing these requirements, some of which are difficult to reconcile, presents a correspondingly significant challenge.

[0007] Based on the prior art, the invention is based on the object of creating a functionally improved motor vehicle bumper arrangement which, in a cost- and weight-saving design, ensures advantageous load behavior and high energy absorption capacity with a modularized structure.

[0008] The solution to this problem consists in a bumper arrangement according to claim 1.

[0009] Advantageous embodiments and further developments of the bumper according to the invention are the subject of the dependent claims.

[0010] Terms such as transverse and longitudinal, top and bottom, horizontal and vertical or longitudinal and transverse direction as well as top and bottom, vehicle side, vehicle-side refer to the installation position of the bumper arrangement in the motor vehicle.

[0011] The motor vehicle bumper assembly comprises a cross member and crash boxes arranged at each end of the cross member, as well as outer end modules. According to the invention, each end module comprises a shell body. The shell body is joined to a crash box, while the cross member is joined to the shell body at one end.

[0012] Preferably, a shield is provided that covers at least part of the shell body at the front. The shield, together with the shell body, forms an end module. The advantageous deformation behavior of an end module is supported by the attached crash box.

[0013] The bumper assembly is composed of components or modules. The individual components are cost-effective to manufacture and feature a lightweight design. The overall structure is platform-compatible. The bumper assembly can be adapted to different vehicles within a series. This is achieved by adapting components or components of the bumper assembly and scaling them to suit the specific vehicle.

[0014] The impact forces are effectively directed to parts of the vehicle where the energy can be effectively and safely absorbed. The crumple zone of the vehicle's front end collapses in a controlled manner, while the passenger cell remains as undeformed as possible. Vehicle occupants are exposed to no or significantly reduced dangerous deceleration. The backward movement of the steering wheel and pedals is also limited, which can help prevent serious injuries.

[0015] The bumper assembly according to the invention exhibits high energy absorption capacity with deformation behavior tailored to the specific vehicle requirements. The geometric design of the modularly complementary components of the cross member, crash boxes, and the end modules designed according to the invention result in a functionally improved motor vehicle bumper assembly. The bumper assembly exhibits advantageous deformation behavior, particularly in the event of an impact with a stationary obstacle such as a tree or a pole, as well as in an offset impact and, in particular, a collision with a laterally mobile obstacle. The motor vehicle bumper assembly according to the invention allows for weight savings compared to known systems, while maintaining comparably good or even better crash performance.

[0016] The shield preferably completely covers the shell body at the front. The shell body can have outer wall sections, particularly lower or side wall sections, that extend beyond the contour of the shield. The wall sections run parallel to the shield, but are partially uncovered by the shield. Openings or perforations and / or passages can be provided in the shield.

[0017] The shield, together with the cross member, in particular with the striker plate arranged at the front of the cross member, acts as an impact surface and thus contributes to the improved crash performance of the bumper assembly according to the invention. In particular, good or low maximum deformation or penetration values ​​can be achieved in compatibility crash tests with a so-called MPDB (Mobile Progressive Deformable Barrier).

[0018] The cross member extends between the inner side walls of the crash boxes in the y-direction of the vehicle.

[0019] A vehicle coordinate system identifies the axes within a motor vehicle. The x-axis corresponds to the vehicle's longitudinal axis, the y-axis corresponds to the vehicle's transverse axis, and the z-axis corresponds to the vehicle's vertical axis.

[0020] An advantageous embodiment of the cross member provides that it has a U-shaped or hat-shaped strut profile and a strike plate.

[0021] The cross member preferably has a front side, which is covered by a strike plate. A practical embodiment provides for the strike plate arranged on the front side of the cross member to be shorter than the front side. Front sections at the ends of the cross member are not covered by the strike plate, which extends over the length of the cross member.

[0022] A shell body has a vertical cross-sectional area in its base region. The vertical cross-sectional area extends in the yz-plane. The average vertical cross-sectional area of ​​the shell body can be determined by the mean of the cross-sectional area in the yz-plane immediately adjacent to the inside of the bottom wall of the shell body and the cross-sectional area in the yz-plane immediately at the open outer surface of the shell body. The average cross-sectional area is at least twice the size of the average cross-sectional area of ​​a crash box. The average vertical cross-sectional area of ​​a crash box can also be determined by the mean of the vertical cross-sectional area at the vehicle-side start of the crash box and the shell-side end of the crash box.The ratio of the mean vertical cross-sectional area of ​​the shell body in the base region to the mean vertical cross-sectional area of ​​the crash box is at least 2:1 and preferably greater. In particular, the ratio is 2.5:1 to 3.5:1, preferably approximately 3:1. All of the above ratios are within + / - 25%.

[0023] In this context, one aspect provides for the plate to partially cover or overlap the front of the cross member. The plate preferably extends over the front sections of the cross member not covered by the strike plate. The plate can be joined to the cross member in the overlap area.

[0024] Each end module has a front section arranged in front of the crash box, to which a transition section is attached at a height level below the crash box, which transitions into a side section.

[0025] The transition section is preferably designed or configured in an arched and / or curved manner and runs downwards and towards the longitudinal side of the vehicle.

[0026] A further advantageous embodiment of an end module provides that the shell body has a bottom wall, and the shell body is supported by the bottom wall on a crash box. The shell body itself has a baffle-like configuration in the front section. In this way, a dual-action absorption zone is formed by the series connection of the end module and its front section, which is arranged in front of a crash box, of the shell body and the crash box.

[0027] The crash box is joined to the floor wall in the support area at the rear, in particular by means of material bonding elements such as welds.

[0028] A particularly advantageous embodiment provides that the shell body has a connecting contour to which the end of the cross member is connected. The connecting contour is configured to match the contour of the ends of the cross member. The connecting contour can be designed such that it encompasses the end of the cross member at its rear wall and the two lateral limbs. Furthermore, the connecting contour can be designed in the shape of a socket, with the socket engaging one end of the cross member in a positionally orientating and restraining manner. It can also be a support tab contour that accommodates the end of the cross member on the inside and outside.

[0029] Preferably, one end of the cross member engages at least partially in a form-fitting manner in the connecting contour and is joined to the shell body.

[0030] In this context, form-fitting means, according to the invention, in particular that a geometric undercut is present between the cross member and the shell body, in particular in the direction of the central longitudinal axis or the y-axis.

[0031] The positive connection between the end of the cross member and the connecting contour in or on the shell body binds the components in the x-axis, y-axis and z-axis, i.e. in three planes.

[0032] The shell body has a base area arranged in front of a crash box and an apron section adjoining the base area. The apron section extends outwards at a height below the crash boxes. The shell contour of the shell body runs from the base area in a troughed manner into the groove-shaped profiled apron section. The transition between the base area and the apron section runs in an arched and curved manner downwards and towards the longitudinal side of the vehicle, i.e. towards the outside of a vehicle. In vertical cross-section, the apron section has a U-shaped, troughed channel shape with the shell contour formed by the base wall and the side walls. The apron section of the shell body and correspondingly the side section of an end module runs from the front section of the end module towards the vehicle side wall and here in particular towards the wheel arch, preferably approximately in the direction of the middle height of the vehicle wheel.

[0033] The shell body is at least twice as large or taller than the cross member in the base area. The height is measured along the z-axis, between the furthest apart points of the shell body on the upper and lower side walls of the base area and the cross member. A favorable ratio of the height of the shell body to the height of the cross member is 2:1 to 4:1, + / - 25% in each case.

[0034] Each end of the cross member or the respective end section at the end of the cross member can extend within the shell body, with the end or end section of the cross member extending into the area in front of a crash box. The bottom wall of the shell body is located between the end of the cross member and the crash box. The shell body is covered at the front by the shield. The end of the cross member is located behind the shield.

[0035] A positive connection between the cross member and the shell body, in particular the strut profile of the cross member and the shell body, can be implemented by a clamp element or a hook element, for example a nose-shaped changeover or clamping tab, on the front side of one end of the strut profile. Such a positive connection element is formed from the plane of the rear wall of the strut profile and engages through a recess in the shell body or engages in a counter-receptacle on a shell body of the end module. A practically advantageous embodiment provides a wedge connection between the end of a cross member and the shell body, in which inclined surfaces support each other, so that a force- and form-fitting connection of the component partners occurs.In particular, in the case of a deformation-related tensile load on the cross member in the y-direction, the shell body and the cross member interact via the connecting contour and the end of the cross member which is accommodated therein in a form-fitting and force-fitting manner.

[0036] The crash box can have a particularly stepped support contour on its front end, which interacts with a counter-support contour on the shell body. In particular, the horizontal and / or vertical end walls of the crash box facing forward toward the shell body of the end module have a step or a similarly designed support contour. A counter-support contour on the shell body, designed to complement the support contour, rests against the support contour. In particular, the crash box and the shell body are joined together in a materially bonded manner.

[0037] A practically advantageous aspect provides for a tow hook connection within a crash box or in the area adjacent to a crash box and the front section of an end module. In particular, a threaded sleeve of the tow hook connection extends through the shield and / or the shell body and is joined to at least one of the components, preferably to both.

[0038] The bumper assembly and its components are made of sheet steel. In particular, ultra-high-strength cold-formed steels can be used for the cross member, as well as for the crash boxes, the shell bodies, and / or the shields or striker plates. Advantageously, the components can be designed as hot-formed and press-hardened steel components. In particular, the shell bodies of the end modules can be hot-formed and press-hardened, whereas the shields are made of ultra-high-strength cold-formed steel. Likewise, the cross member or its strut profile and the striker plate can be hot-formed and press-hardened steel components. A combination of components made of hot-formed and press-hardened steel with components made of cold-formed steel is also advantageous. In particular, the strut profile of the cross member is a hot-formed and press-hardened steel component, whereas the striker plate provided at the front is made of a cold-formed steel, in particular an ultra-high-strength cold-formed steel.

[0039] The shell bodies preferably have a tensile strength Rm of greater than or equal to (≥) 1,350 MPa. The upper limit of the tensile strength lies within the values ​​known to those skilled in the art for UHSS (Ultra High Strength Steel) or AHSS (Advanced High Strength Steel) steels.

[0040] Although an advantageous embodiment of the cross member provides for it to have a U-shaped or hat-shaped strut profile open to the front, which is closed by a locking plate or at least closed over most of its length, the cross member can also have a closed hollow profile or be roll-formed. The cross member also preferably has a tensile strength Rm of greater than or equal to (≥) 1,350 MPa.

[0041] An advantageous embodiment of a shell body provides for it to have a bead, a fold, and / or a transition in the edge wall sections. Such beads, folds, or transitions extend along the edge wall sections of the shell body. The shapes have a stiffening function. Furthermore, they can form functional surfaces along the edge wall sections, where the front signs are supported or the end sections or ends of the cross member are connected.

[0042] A further inventive aspect provides that the components of the bumper assembly, i.e., the cross member or the strut profile and the locking plate of the cross member, as well as the end modules or the shell bodies and the shields, are joined together in their respective joining areas using a mixed joining technique. This involves a combination of material-locking elements, preferably welded joints, and form-locking elements such as wedge bodies and wedge surfaces, embossing, clinching, or interlocking. It is understood that screw or bolt connections can be used alone or using a mixed joining technique for joining component components.

[0043] Crash performance can be further improved if a cross member and / or at least one support strut is arranged below the cross member. A cross member extends transversely in the y-direction with a distance in the z-direction below the cross member. The cross member is connected, for example, via brackets fixed in the lower area of ​​the end modules. The cross member can also be supported by another pair of crash boxes or similarly configured impact absorbers. The cross member is connected to the crash boxes in a suitable manner.

[0044] For example, a support strut can extend diagonally from the lower section of an end module toward the cross member. A cross strut can be connected to a shield at the rear. This allows for additional regional reinforcement of the system, which improves the deformation and energy absorption behavior in the event of a side impact on the bumper assembly.

[0045] The wall thicknesses of the individual components of the bumper assembly—i.e., the strut profile, strike plate, shell body, and shield—can be the same or different. In particular, the strut profile, the strike plate, the shell bodies, or the shields themselves can have different wall thicknesses. Target deformation zones can be defined by partially varying the wall thickness. Furthermore, such designs contribute to weight optimization.

[0046] The invention is described in more detail below with reference to exemplary embodiments illustrated in the drawings. In the drawings: Figure 1 shows a front view of a motor vehicle bumper arrangement according to the invention; Figure 2 shows the bumper arrangement in a rear view from the motor vehicle; Figure 3 shows a section through the representation of the Figure 1 along the line AA; Figure 4 a section through the representation of the Figure 1 along the line BB; Figure 5 a section through the representation of the Figure 1along the line CC; Figure 6 a view of a shell body; Figure 7 a section of the lateral area of ​​a bumper arrangement showing the shell body of an end module and the schematically indicated connection of a cross member; Figure 8 a view of an end module with the technically schematic representation of the cover contour of a shield and the representation of the crash box contour; Figure 9 the representation of a possible modification in the arrangement of the cross member and its connection to an end module; Figure 10 a further modification of the bumper arrangement in a technically schematic representation; Figure 11 a further modification of the bumper arrangement showing the shell body of an end module and the end module-side end of a cross member and Figure 12 a section of the connection area between a crash box and a shell body in a perspective representation.

[0047] Where appropriate, the Figures 1 to 11 The same reference symbols are used for identical or similar components or parts, even if a repeated description is omitted for reasons of simplification.

[0048] Based on the Figures 1 to 5 A first embodiment of a bumper assembly 1 according to the invention for a motor vehicle is described. The bumper assembly 1 is used in the front or rear area, in particular in the front area of ​​the body of a motor vehicle.

[0049] The bumper assembly 1 comprises a cross member 2 arranged transversely to the longitudinal members (not shown here) of a motor vehicle. The bumper assembly 1 is supported on the longitudinal members via crash boxes 3, which are provided at the ends of the cross member 2. In addition to the cross member 2, the crash boxes 3 are intended to absorb the energy resulting from an impact by converting it into deformation energy.

[0050] The cross member 2 extends between the inner side walls of the crash boxes 3. The cross member 2 has a U-shaped or hat-shaped strut profile 4 formed in one piece from a metal sheet, in particular from sheet steel. The strut profile 4 has a rear wall 5 with two legs 6, to each of which an outwardly directed longitudinal flange 7, 8 is connected. A strike plate 9 is provided on the front side of the strut profile 4. The strike plate 9 extends in the y-direction over almost the entire length of the front side 10 of the cross member 2. In the middle longitudinal section 11 of the cross member 2 (see Figure 3) The upper longitudinal flange 8 is adjoined by a switch 12 directed rearward in the x-direction towards the vehicle. The strike plate 9 also has a rearward-facing switch 13 in the central longitudinal section 11, which overlaps the switch 12 on the upper longitudinal flange 8 of the strut profile 4. On the lower longitudinal flange 7 of the strut profile 4, the strike plate 9 rests against the strut profile 4 in the central longitudinal section 11 of the cross member 2.

[0051] The bumper assembly 1 has an end module 14 at each end. Each end module 14 has a shell body 15 and a shield 16 covering the shell body 15 at the front. The shell body 15 is joined to the crash box 3. One end 17 of the cross member 2 is joined to the shell body 15. The joining between the components is achieved, in particular, by means of a material bond, such as welding.

[0052] A shell body 15 in a view is shown in the Figure 6 .

[0053] An end module 14 has a front section 18 arranged in front of the crash box 3, to which a transition section 19 is laterally connected at a height level below the crash box 3, which transition section 19 merges into a side section 20.

[0054] The transition section 19 is configured in an arc shape or is curved downwards and in the direction of the longitudinal side of the vehicle or the wheel housing.

[0055] The shell body 15 has a bottom wall 21. A crash box 3 is supported on the outside, or on the outer surface of the bottom wall 21 of the shell body 15 facing the vehicle. Towards the end sections 22 of the cross member 2, a shell body 15 has a connecting contour 24 in its side wall 23, which is directed forward from the bottom wall 21 and adjacent to the end 17 of the cross member 2, to which the end of the cross member 2 is connected.

[0056] The shell body 15 has a base region 25 arranged in front of a crash box 3 and an apron section 26 adjoining the base region 25. The apron section 26 extends outwardly toward the longitudinal sides of the vehicle at a height level below the crash box 3.

[0057] The shell contour of the shell body 15 runs from the base region 25 in a troughed manner into the groove-shaped, profiled apron section 26. The transition 37 between the base region 25 and the apron section 26 runs in an arcuate and curved manner downwards and toward the longitudinal side of the vehicle, i.e., toward the outside of a vehicle. In vertical cross-section, the apron section 26 has a U-shaped, troughed channel shape 38 with the shell contour formed by the base wall 21 and the side walls 23. The channel shape 38 tapers open at the end of the apron section 26.

[0058] The shield 16 is arranged at the front in front of the shell bodies 15 and is configured curved in an arc section 27. The shield 16 can partially overlap the cross member 2 at the front. Such a configuration is shown in Figure 8 The end 17 of the cross member 2 lies in the connecting contour 24 of the shell body 15. The plate 16 covers the front of the assembly. The plate 16 rests flat against parallel surfaces of the shell body 15 and overlaps the end 17 and the strike plate 9 of the cross member 2 in an overlap area 28.

[0059] In one embodiment of a bumper arrangement 1, as shown in the Figure 10As explained, the striking plate 9 is shorter than the front side 10 of the cross member 2, so that short sections 29 on the front side 10 of the cross member 2 are not covered by the striking plate 9. These front sections 29 are covered by the plate 16, with the striking plate 9 and the plate 16 lying approximately flush with one another in a joint area.

[0060] The Figure 7 schematically shows that the end 17 of the cross member 2 engages at least partially in a form-fitting manner with the connecting contour 24. The end 17 is joined to the shell body 15 in the area of ​​the connecting contour 24. The end 17 of the cross member 2 or the end 30 of the strut profile 4 is trapezoidally configured. A form-fitting joint is created, which may be supplemented by material-bonding elements.

[0061] In principle, a mixed joining technique of joining partners is also possible, in which, for example, the strut profile 4 and the shell body 15 are joined by means of material locking elements and form-locking elements.

[0062] The shell body 15 is formed from a steel sheet, in particular from a manganese-boron steel sheet. In particular, the shell body 15 is hot-formed and press-hardened and has a tensile strength Rm of greater than or equal to (≥) 1,350 MPa.

[0063] The shields 16 can also be hot-formed and press-hardened with comparable material properties. The shields 16 can also be cold-formed and made of ultra-high-strength cold-formed steels.

[0064] The strut profile 4 of the cross member 2 also has a tensile strength Rm of greater than or equal to (≥) 1,350 MPa. The strut profile 4 is preferably hot-formed and press-hardened.

[0065] The end 17 of the cross member 2 and an end-side longitudinal section, or the end section 22 of the cross member 2, can extend into the shell body 15, namely into an area that lies in front of the crash box 3. Such a design is shown in the Figure 8 The crash box contour is indicated by the dashed line C. The contour of the strike plate 9 is illustrated by the dashed line S. At the front, the end module 14 as well as the end longitudinal section 22 extending into the shell body 15 and the end 17 of the cross member 2 are covered by the plate 16.

[0066] In the presentation of the Figure 9one can see the crash box contour, indicated by the dashed line C. The contour of the end 17 of the cross member 2 is indicated by the dashed line E. One can see that the cross member 2, or rather that the end 17 of the cross member 2, does not extend to the crash box contour C. The end 17 of the cross member 2 is connected to the shell body 15, but ends at a distance in the y-direction in front of a crash box 3.

[0067] In the Figure 10In the modification shown, the end 30 of the strut profile 4 of the cross member 2 extends within the shell body 15 in front of the crash box 3 and extends beyond the entire crash box contour C. The striking plate 9 of the cross member 2 ends in front of the shield 16. However, it is also possible for the striking plate 9 to extend over the end 30 of the strut profile 4, which lies in front of the crash box 3. The bottom wall 21 of the shell body 15 is located between the cross member 2 and the end 17 on the vehicle side. At the front, the end module 14 or the shell body 15 is covered by the shield 16.

[0068] A crash box 3 has a stepped support contour 32 on the front side, in particular in the front z-axis oriented vertical end faces 31, which interacts with a counter support contour 33 on the shell body 15. This is shown in the illustration of the Figure 4 shown in a sketchy manner and in particular based on the Figure 11to recognize. The shell body 15 (cf. Figures 6 and 4 ) has trough-shaped impressions 34 in its bottom wall 21. The impressions 34 are formed towards the outside or towards the plate 16. The Figure 5 shows such an indentation 34 or depression. The transitions at the indentations 34 form the counter-support contour 33, against which the support contour 32 rests.

[0069] A shell body 15 has a changeover 36 in edge-side wall sections 35, which has a stiffening function in the edge-side wall sections 35.

[0070] Openings 39 or perforations 39 may be present in both the shell body 15 and the shield 16 (see, for example, Figures 4 or 7 ). The openings 39 can also be designed as passages.

[0071] When modifying the bumper assembly 1 or the connection and joining of the end 17 of the cross member 2 or the end 30 of the strut profile 4, as shown in the Figure 11 As shown, a clamp- or hook-like joining element 40 is provided at the end 30. This engages through an abutment element 41 in the shell body 15. The abutment element 41 can, for example, be an opening in the bottom wall 21 of the shell body 15. The abutment element 41 can also be designed in a slot-shaped manner, as well as as a stamped or embossed form-fitting abutment element 41.

[0072] In the shell body 15, a form-locking element 42 (see Figure 6 ). This can be a depression or elevation. The form-locking element 42 interacts with a correspondingly complementary form-locking element 43 at the end 30 of the strut profile 4 of the cross member 2. The form-locking element 43 is in the Figure 7 shown, whereby it should be noted that the form-locking element 43 is provided in the rear wall 5 of the strut profile 4.

[0073] The Figure 12 clarifies once again the connection and support of a crash box 3 on the rear side of the base wall 21 of a shell body 15. The crash box 3 has a stepped support contour 32 on its front side with a step 45 formed on a side wall 44 of the crash box 3. The support contour 32 interacts with a counter-support contour 33 on the shell body 15. The counter-support contour 33 is formed on an arcuate section of a recess or indentation 34 of the counter-support contour 33. Corresponding support contours 32 and counter-support contours 33 are formed on both sides, i.e. also on the opposite side of the crash box 3 and the side wall 46 provided there.

[0074] In this way, the crash box 3 is tied and stabilized to the shell body 15 in the z-axis and in the y-axis.

[0075] An end module 14 has a vertical cross-sectional area in the base region 25 of the shell body 15 that is at least twice as large, in particular a multiple of the vertical cross-sectional area of ​​a crash box 3. The ratio of the cross-sectional areas of the base region 25 of the shell body 15 and the crash box 3 to one another is essential, with the vertical cross-sectional ratio of the base region 25 and the vertical cross-sectional ratio of the crash box 3 being at least 2:1, preferably 3:1. The cross-sectional ratio can be from 2:1 to 4:1, in particular up to 3.5:1, in each case + / - 25%.

[0076] To determine the cross-sectional ratio, a mean vertical cross-sectional ratio can be used. The area can be determined in the area of ​​the bottom wall 21 of the shell body 15, in the center of the base area 25, and on the open outer side. The same applies to a crash box 3. There, the cross-sectional ratio can be determined at the beginning, in the middle, and at the end of the crash box 3, and an average value can be calculated from the respective cross-sectional ratios.

[0077] In the event of an impact, the base area 25 of the shell body 15 of an end module 14, which has a significantly larger cross-section, ensures that the force or energy is distributed over a large area.

[0078] The ratio of the height h1 of the shell body 15 in the base area 25, measured in the z-axis, between its upper side wall 23' and its lower side wall 23", to the height h2 of the cross member 2, measured in the z-axis, is dimensioned between 2:1 and 4:1, each with a tolerance or a variation of + / - 25% within the scope of the design concept.

[0079] As can be seen in particular from the Figure 4 As can be seen, the shield 16 can also have a trough- or groove-like depression 47. In the area of ​​the trough-like depression, the shield 16 rests against the bottom wall 21 of the shell body 15 and is supported thereon. In the contact area, the bottom wall 21 and the shield 16 can be joined, for example, by a material bond. This can also be achieved by gluing.

[0080] In principle, a cross member extending in the y-direction can be provided below the cross member 2. Reference symbol:

[0081] 1 - bumper arrangement 2 - cross member 3 - crash box 4 - strut profile of 2 5 - rear wall of 4 6 - leg 7 - lower longitudinal flange 8 - upper longitudinal flange 9 - strike plate 10 - front of 2 11 - middle length section 12 - changeover 13 - changeover 14 - end module 15 - shell body 16 - shield 17 - end of 2 18 - front section of 14 19 - transition section 20 - side section 21 - floor wall of 15 22 - end section of 2 23 -Side wall 23' -Upper side wall 23" -Lower side wall 24 -Connection contour 25 -Base area 26 -Apron section 27 -Curved section 28 -Overlap area 29 -Section 30 -End of 4 31 -Front side of 3 32 -Support contour 33 -Counter support contour 34 -Imprint 35 -Wall section of 15 36 -Changeover 37 -Transition 38 -Channel shape 39 -Opening 40 -Joining element 41 -Abutment element 42 -Form-locking element 43 -Form-locking element 44 -Side wall 45 -Step 46 -Side wall 47 -Recess of 16 C -Crashbox contour S -Shield contour h1 -Height v. 15 h2 -Height v. 2

Claims

1. A bumper arrangement for a motor vehicle, which has a cross member (2) and crash boxes (3) arranged at each end of the cross member (2) as well as outer end modules (14), wherein each end module (14) has a shell body (15), wherein the shell body (15) is joined to a crash box (3) and one end (17) of the cross member (2) is joined to the shell body (15), characterized in that each shell body (15) has a base region (25), arranged in front of a crash box (3), and an skirt section (26), adjoining the base region (25), wherein the skirt section (26) extends outwards at a height level below the crash box (3).

2. The bumper arrangement according to claim 1, characterized in that the shell body (15) is covered at the front at least in regions by a shield (16).

3. The bumper arrangement according to claim 1 or 2, characterized in that the cross member (2) has a U-shaped or hat-shaped strut profile (4) and a closing plate (9).

4. The bumper arrangement according to claim 3, characterized in that the cross member (2) has a front side (10) and the closing plate (9) arranged on the front side (10) of the cross member (2) is shorter than the front side (10).

5. The bumper arrangement according to any one of claims 1 to 4, characterized in that the shield (16) partially covers or overlaps the cross member (2) on the front side.

6. The bumper arrangement according to any one of claims 1 to 5, characterized in that each end module (14) has a front section (18), arranged in front of the crash box (3), to which a transition section (19) is laterally connected at a height level below the crash box (3), which transition section merges into a side section (20).

7. The bumper arrangement according to claim 6, characterized in that the transition section (19) is arcuate and / or curved downwards and in the direction of the vehicle longitudinal side.

8. The bumper arrangement according to any one of claims 1 to 7, characterized in that each shell body (15) of an end module (14) has a bottom wall (21) and the shell body (15) is supported with the bottom wall (21) on a crash box (3).

9. The bumper arrangement according to any one of claims 1 to 8, characterized in that the shell body (15) has a connecting contour (24) to which the end (17) of the cross member (2) is connected.

10. The bumper arrangement according to claim 9, characterized in that the end (17) of the cross member (2) at least partially engages in a form-fitting manner in the connecting contour (24) and is joined to the shell body (15).

11. The bumper arrangement according to any one of claims 1 to 10, characterized in that the end (17) of the cross member (2) extends within the shell body (15) at least in regions up to the crash box (3).

12. The bumper arrangement according to any one of claims 1 to 11, characterized in that the crash box (3) has a stepped support contour (30) on the front side, which cooperates with a counter-support contour (31) on the shell body (15).

13. The bumper arrangement according to any one of claims 1 to 12, characterized in that the shell bodies (15) are hot-formed and press-hardened and / or have a tensile strength Rm of greater than or equal to (≥) 1,350 MPa and the shields (16) are cold-formed.

14. The bumper arrangement according to any one of claims 1 to 13, characterized in that each shell body (15) has a bead, a fold and / or a turned-over portion (36) in edge-side wall sections (35).

15. The bumper arrangement according to any one of claims 1 to 14, characterized in that the cross member (2), the strut profile (4), the closing plate (9), the shell body (15) and / or the shield (16) are joined by means of a combination of material-locking elements and form-locking elements.

16. The bumper arrangement according to any one of the preceding claims, characterized in that the ratio of the mean vertical cross-sectional area of the shell body (15) in the base region (25) to the mean vertical cross-sectional area of the crash box (3) is between 2:1 and 4:1, in particular 3:1, in each case + / - 25 %.

17. The bumper arrangement according to any one of the preceding claims, characterized in that the ratio of the height (h1), measured in the z-axis, of the shell body (15) in the base region (25) between its upper side wall (23') and its lower side wall (23") to the height (h2) of the cross member (2), measured in the z-axis, is between 2:1 and 4:1, in each case + / - 25 %.