Bumper beam

Abstract

The invention relates to a bumper cross member (1) for a vehicle, comprising a beam (2) which extends with its longitudinal axis in the vehicle transverse direction (y-direction) and is open in the direction of travel (x-direction), said beam having a chamber (8) enclosed by an upper leg (5), a lower leg (6) and a web (7) connecting the two legs (5, 6) in the vehicle vertical direction z-direction; a closing plate (3) connected to legs (5), (6) of the beam (2), having an opening across the beam in the vertical direction (z-direction) of the vehicle; and an insert (9), (9.1) which is arranged in the chamber (8) of the beam (2) and which has an upper leg (10), a lower leg (11) and a back (12) which connects the legs at the rear ends of the legs (10), (11), the open side of which faces the direction of travel (x-direction) and the legs (10), (11) of which are connected to the closing plate (3). A particular feature is that the back (12) of the insert (9), (9.1) is convex at least in the middle section thereof with respect to the longitudinal extent (y-direction) thereof.

Description

TECHNICAL FIELD

[0001] The invention relates to a bumper beam for a vehicle, which bumper beam: has a beam which extends with its longitudinal axis in the vehicle transverse direction (y direction) and which is open in the driving direction (x direction), which beam has a cavity which is surrounded by an upper leg, a lower leg and a web which connects the two legs in the vehicle vertical direction (z direction); has a closing plate which spans the beam opening in the vehicle vertical direction (z direction) and which is connected to the legs of the beam; and has an insert which is arranged in the cavity of the beam, which insert has an upper leg, a lower leg and a back which connects the legs at their rear terminal ends, the open side of the insert facing in the driving direction (x direction) and the legs of the insert being connected to the closing plate. BACKGROUND

[0002] Bumper beams are arranged in motor vehicles at the front and / or at the rear. The bumper beam comprises a beam profile which is typically configured in its cross section as a hat and which is fixed at the vehicle side. The profile is formed by one upper leg, one lower leg and one web which connects the two legs at their longitudinal side ends facing the vehicle chassis. The beam is open in the driving direction and thus has a cavity which is typically formed in the cross section, for example, as a U, which is open in the driving direction. The web connecting the legs faces the vehicle chassis. The beam is fixed at the vehicle side with an intermediate connection to a crash box. The two legs surrounding the cavity of the beam have at their ends flanges which are bent away from the cavity in the perpendicular direction (y direction). On these flanges a closing plate is fixed in order to close the cavity at the front. The closing plate connected to the flanges of the legs also serves to reinforce the beam, since a box profile is thereby provided in the longitudinal extension of the beam over the extension of the closing plate. With this design it is prevented that one or the other leg of the beam moves relative to the other leg in the case of a collision to be absorbed. In some design variants the closing plate extends over the entire or almost the entire longitudinal extension of the beam.

[0003] The deformation behavior and strength of such a bumper beam is decisively set by the depth of the profile of the beam. The depth of the bumper beam and thus its extension in the longitudinal direction of the vehicle (x-direction) is usually limited. This has to be taken into account when dimensioning the profile depth of the beam in connection with the design of the bumper beam. In some cases, however, this is not sufficient to impart the desired strength to the bumper beam. In order to remedy this here, it is proposed in WO 2016 / 163054 A1 to install a reinforcing element in the chamber of the beam. The reinforcing element known from this prior art is an open or closed reinforcing element of substantially trapezoidal design in cross section, which is welded with its shorter trapezoidal leg to the web of the connecting leg of the beam. In the case of the reinforcing element being designed as an open design, the reinforcing element has legs which are bent outwards in the vertical direction, which engage into the joint between the bent flange of the leg of the beam and the closing plate. The reinforcing element is positioned centrally with respect to the beam and extends only over a short section with respect to the longitudinal extension of the beam.

[0004] Even if the collision behavior of the bumper beam in the so-called column test can be improved by the installation of such a reinforcing element, disadvantages still have to be tolerated. These relate on the one hand to the necessity of welding the reinforcing element to the web of the beam profile, which is not without problems, especially when the reinforcing element is closed and thus constructed as a hollow chamber profile, due to the lack of or only very difficult accessibility of the joint.

[0005] Another bumper beam with an insert is known from WO 2019 / 072653 A1. The insert is U-shaped and connected to the closing plate with its legs facing forwards in the driving direction over its entire length by means of one weld seam each. The back of the insert is straight in the longitudinal extension of the insert and arranged with a distance within the chamber of the beam. The insert reinforces the bumper beam. In the central section of the insert a reinforcing element is additionally inserted.

[0006] US 2023 / 0143784 A1 discloses a bumper beam. The bumper beam comprises a beam having a hat-shaped cross-sectional profile. Its open side facing forwards in the vehicle direction is closed by a closing plate. In connection with the prior art Figure 9 In the described embodiment, the bumper beam has an insert. The insert is also shaped like a hat and has an upper leg and a lower leg and a back connecting the two legs. The insert is connected with its straight back to the inner side of the closing plate. The open side of the insert faces the chassis of the vehicle.

[0007] The aim pursued with the insert as described above is to reinforce the bumper beam, thus designing the bumper beam to be less deformable. While such a bumper beam should be reinforced by means of such an insert on the one hand, it must also meet the usual test requirements, for example the MPDB (moving progressive deformable barrier) test or the column test. The impact force should be absorbed not only via the crash box provided for this purpose, but also via the deformation of the bumper beam. Thus, the bumper beam is not allowed to be designed too rigidly, for example in those sections which should deform during the MPDB test. It is not a problem in conventional bumper beams that they break on their side facing the vehicle chassis after a certain deformation and then can no longer absorb energy. To counter this, the beam and the insert are embodied with a corresponding wall thickness to resist premature breaking. Here, greater weight of the bumper beam is tolerated. SUMMARY

[0008] Thus, starting from the discussed prior art, the object of the present application is to improve a bumper beam in which an insert is arranged in the chamber of the beam, such that the bumper beam has improved crash behavior, in particular without cracks or without breaking, and is also able to absorb higher deformation rates.

[0009] According to the application, this task is solved by a bumper beam of the type mentioned at the outset, in which the back of the insert is shaped convex with respect to its longitudinal extension (y-direction) at least in its middle section.

[0010] The direction indications used within the framework of these explanations are those directions which are generally used in motor vehicles. Thus, the x-direction is the longitudinal extension direction of the vehicle, the y-direction is the transverse direction (width direction) thereof, and the z-direction is the direction of the vertical axis.

[0011] In the bumper beam, the back of the insert is convexly shaped at least in its middle section facing the chassis of the vehicle. Thereby, a material preset is provided, such that a greater deformation can be absorbed without cracks or breaking in the case of an MPDB load. Thus, in the bumper beam, the convex shaping of the back of the insert away from the closing plate, wherein the convex shaping extends in the longitudinal extension direction of the insert, is already preformed in the direction of the degree of deformation of the convex shaping, such that a deformation against the force absorption is already predetermined thereby in the case of an MPDB load. The tensile forces acting on the back in the case of the necessary force absorption are correspondingly lower.

[0012] The intermediate section of the insert preferably extends over at least 25%, however typically not more than 70% to 80% of the distance of the two crash boxes which are used on the bumper beam to connect the bumper beam to the longitudinal beams of the vehicle. The intermediate section preferably occupies at least 35% to 40%, however not more than 60% to 70% of the longitudinal extension of the insert.

[0013] In a preferred embodiment, the improved crash behavior described above is supported in that a transition section is provided between the intermediate section of the insert with its convex shaping and the respective end sections, which transition section is formed by a change in the depth (x direction) of the insert due to the shaping of the back. In one embodiment, the transition section is concavely shaped, however can also have a convex shaping. Through these transition sections in the back of the insert, a material reservoir is created, so that the insert can be stretched in the mentioned load cases in the insert sections without overloading due to the tensile forces acting on the back.

[0014] The insert is typically located centrally with respect to the longitudinal extension of the beam in the chamber of the beam which opens in the driving direction. However, a different positioning is also absolutely possible, for example when a different crash behavior with respect to the width of the vehicle (longitudinal extension of the bumper beam) is desired.

[0015] In order to further improve the crash behavior, for example in the MPDB load case, i.e. the bending of the bumper beam in the x direction, it is provided that the insert is connected to the closing plate only in individual and mutually spaced apart sections with respect to the longitudinal extension of the insert. The closing plate together with the insert connected thereto is located on the side of the obstacle and thus on the inside of the deformation of the bumper beam. Through this measure, the sections located between the connecting sections of the insert with the closing plate serve as prepared bending or kinking sites. The reason for this is the absence of the weld seams which are typically present in order to connect the insert to the closing plate and the resulting weakening. This deformation behavior on the obstacle-facing side of the bumper beam can additionally be supported in that the insert does not touch the closing plate between its connecting sites with the closing plate, so that the leg ends facing the closing plate are spaced apart from the closing plate in these sections. With respect to the longitudinal extension of the insert, the sum of the extensions of the connecting sections of the insert with which the insert is connected to the closing plate in this direction is smaller than the sum of the sections which are spaced apart from the closing plate according to the preferred design described above and which are not connected to the closing plate.

[0016] Due to the special embodiment of the insert in the bumper beam, it is easy to meet the requirements placed on the crash behavior. The crash behavior of the bumper beam is decisively influenced by the embodiment of the insert. Due to the special design of the insert, both the beam and the insert can be produced with a relatively thin wall thickness. The same applies to the closing plate. Despite the improved crash behavior, the overall weight of the bumper beam is correspondingly low.

[0017] According to a preferred embodiment, the insert is arranged within the chamber of the beam in such a way that it does not touch the beam and thus a sufficient distance is left between the insert and the beam. If the bumper beam is provided with a coating, for example in the process of dip painting, there is no wedge-shaped portion which can not be wetted.

[0018] In order to achieve the above-mentioned crash behavior or in addition thereto, the insert can have insert sections which differ in their height, their width, the end contour of the legs and / or their material thickness in the direction of the longitudinal extension thereof. In this way, the crash behavior and the strength of the bumper beam can be influenced solely by the corresponding design and selection of the insert to be installed in the chamber of the beam held by the closing plate. Thus, the same beam and the same closing plate can be used for vehicles which differ in their crash behavior, wherein the respective bumper beam formed thereby with the corresponding insert differs only in the different design of the respective insert and / or the design of the connecting section thereof to the closing plate.

[0019] Typically, the insert sections of the insert are designed mirror-symmetrically about the center of the insert. If a different crash behavior is provided over the width of the vehicle and thus over the longitudinal extension of the bumper beam, this can also be designed differently.

[0020] The transitions from a first insert section to an adjacent insert section can be arranged identically in both legs of the insert and also aligned with one another in the z-direction. It is however also possible for such transitions to be embodied differently in the upper leg than in the lower leg. This relates not only to the positioning of the transitions but also to the degree of change.

[0021] In a preferred embodiment of such a bumper beam, the insert is divided into a plurality of insert sections in the direction of its longitudinal extension. Such an insert can for example have a central section as a first insert section and end sections connected thereto with intermediate connecting transition sections. In a preferred design, the transition sections between the two end sections and the central section are embodied in the cross-sectional area of the insert as a girth, wherein such tapering can relate not only to the height and / or width of the insert. In the embodiment already described above, such a transition section is girthed by the concave embodiment of the back, wherein in addition to further emphasizing such girth, the leg ends of the insert with the concave embodiment of the back also have concave recesses in the x direction.

[0022] In such an embodiment of the bumper beam, the end sections can also be divided again into a plurality of individual sections, which are each provided by a transition section that is girthed in the depth direction (x direction) of the insert. Typically, such a bumper beam has a long longitudinal extension and extends for example into the region in which the crash box is connected to the bumper beam. It is provided in one embodiment that the outer end sections of the insert overlap in the x direction with the vehicle center-facing wall of the crash box.

[0023] Such a bumper beam is typically connected to the closing plate with the legs of its two end sections and with the first section of the central section. According to one embodiment, the sections of the insert that lie between these connecting sections are not connected to the closing plate and have at the end of their legs corresponding, typically concave notches so that they do not contact the closing plate. According to another design, it is provided that the intermediate sections are connected to the closing plate in their edge sections and additionally also in the center of the central section. The number and length of the corresponding connections or connecting sections between the insert and the closing plate, which are typically caused by welding, have an influence on the crash performance. This can therefore also be used to design the crash performance of the bumper beam.

[0024] As a further measure which can complement or replace the above measures for improving the crash behavior of the bumper beam, it is provided that the bumper beam has a bending-on structure. This means that the insert, the beam and / or the closing plate each have one or more bending-on structures. These bending-on structures serve the purpose that in the event of energy absorption, for example in a column test, the bumper beam bends at predetermined defined points, more precisely at the places where the bending-on structures are arranged. Thereby, the bumper beam can better follow the contour of the obstacle, for example a pole. Typically, the bumper beam has a plurality of such bending-on structures. In this case, they are arranged mirror-symmetrically with respect to the center of the bumper beam and thus mirror-symmetrically with respect to the longitudinal extension of the respective component provided with such bending-on structures with respect to the center of the respective component. Preferably, such bending-on structures are not caused by material weakening, but are provided by a corresponding pressing, typically in the form of a rib and / or by a notch. Depending on the design concept of the desired bending behavior of the bumper beam, the insert, the beam and / or the closing plate can each have a bending-on structure in the x-direction in the aligned position.

[0025] In one embodiment it is provided that the end of the leg of the insert facing the beam opening direction has a bending-on rib which is preferably embodied as a positive structure. Such a rib opens towards the beam opening direction and typically has its greatest pressing-out at the leg end. It typically extends towards the back of the insert before the transition into the back. In order to achieve a bending behavior in both legs of the insert which is uniform in terms of behavior, both legs of the insert typically each carry a bending-on structure which is aligned with one another in the vertical direction (z-direction) of the insert.

[0026] In the same way, the leg end of the beam can be provided with one or more bending-on ribs. In one preferred embodiment it is provided that the beam has such a bending-on rib only centrally in both legs with respect to its longitudinal extension. At other locations, the beam has notches as bending-on structures. A combination of bending-on ribs and notches or recesses is also possible. At the free end of the leg a notch can be provided, for example to accommodate a bending-on rib of the closing plate.

[0027] The closing plate can also be provided with such bending-on structures. These bending-on structures are typically bending-on ribs which extend in the z-direction as negative structures and thus pressed towards the beam. The bending behavior can be influenced by the length of extension of these bending-on ribs. Preferably, these ribs of the closing plate do not extend over the entire height thereof. In this embodiment, the bending-on structures in the closing plate which are located between the legs of the beam can be distinguished from the bending-on structures which engage into the leg ends of the beam.

[0028] The above-mentioned equipment of the bumper beam is particularly effective in combination with the above-mentioned design of the insert, in which the legs of the insert are only partially connected to the closing plate. In this design, the closing plate is not connected to the legs of the insert in the region of the bent-on structure.

[0029] The beam of the bumper beam is typically a hat profile. The hat profile can be made from a steel sheet blank. In this case it is expedient that the closing plate and the insert are also made from a steel sheet blank, since these components of the bumper beam can then be joined to one another in a simple manner by welding without any problems.

[0030] In the claimed bumper beam, the crash behavior can be optimized or matched to the respective requirements in a variety of ways and methods by designing the insert, for example such that the deformed bumper beam in the column test lies against the peripheral surface of the column without cracks or without breaking.

[0031] It should also be emphasized with regard to the bumper beam according to the invention that, as a result of the connection of the insert to the closing plate, the connection remains even if the beam of the bumper beam breaks on its side facing the vehicle chassis when excessive forces are absorbed, for example in a column test. The breaking on the side of the bumper beam facing away from the vehicle chassis is avoided by the connection of the insert. BRIEF DESCRIPTION OF DRAWINGS

[0032] The invention has been described below with reference to embodiments in accordance with the drawings. In the drawings: Figure 1 a three-dimensional view of a bumper beam according to the invention, in which the closing plate on the front side is shown transparently in order to allow the insert located therein to be seen.

[0033] Figure 2 :a perspective view of the insert of the bumper beam of Figure 1 Figure 3 :a longitudinal sectional view in the x-y plane of the bumper beam of Figure 1 Figure 4 a further bumper beam according to the invention, which differs from that of Figure 3 by the use of a further insert, Figure 5 :a bumper beam of Figure 4 moving towards an obstacle, Figure 6 : a bumper beam of Figure 5 deformed at an obstacle, Figure 7 a diagram corresponding to the diagram illustrated, however with a beam according to the prior art, Figure 6 Figure 8 perspective view of a bumper beam according to the present application; Figure 9 : Figure 8 bumper beam in which the closing plate is partially removed in order to see the beam, with a first insert, Figure 10 : Figure 8 bumper beam in which the closing plate is partially removed in order to see the beam, with an alternative insert, Figure 11 : Figure 9 perspective view of an insert of a bumper beam, Figure 12 : Figure 11 front view of an insert, Figure 13 : Figure 10 perspective view of an insert of a bumper beam, Figure 14 : Figure 13 front view of an insert, Figure 15 : Figure 9 longitudinal section view of a bumper beam in the x-y plane, Figure 16 : Figure 10 longitudinal section view of a bumper beam in the x-y plane, Figures 17a-17c : diagram for visualizing Figure 9 bending behavior of a bumper beam at a column test, wherein, Figure 17a a first deformation is shown, Figure 17b a further deformation is shown when the obstacle intrudes deeper, and Figure 17c a final deformation of the bumper beam at the ongoing column test is shown. DETAILED DESCRIPTION

[0034] A bumper beam 1 for a motor vehicle comprises a beam 2. The beam 2 is a U-profiled profile made of a steel plate blank. In an embodiment not shown in the figures, the beam 2 is embodied as a hat profile. The beam 2 extends over the entire longitudinal extension of the bumper beam 1. The open side of the beam 2 faces in the driving direction (x direction) in the forward direction. The beam 2 is closed on the front side by a closing plate 3 in a manner and method known per se. Two crash boxes 4, 4.1 are connected to the back side of the beam 2 facing the vehicle chassis at a distance from one another. The bumper beam 1 is fixed to the chassis side via these crash boxes.

[0035] The profiled contour of the beam 2 is provided by an upper leg 5, a lower leg 6 and a web 7 connecting the two legs 5, 6 on their chassis-facing long sides. The two legs 5, 6 and the web 7 enclose a chamber 8. This chamber is closed on the front side by the closing plate 3. The beam 2 thus, together with the closing plate 3, constitutes a hollow-chamber profile.

[0036] Inside the chamber 8 there is arranged an insert 9. The insert 9 is also profiled in the shape of a U. Its open side faces in the same way as the open side of the beam 2 in the direction of travel (x direction). The insert is connected to the side of the closing plate 3 facing the chamber 8 by a welded connection with the end face sections of its legs 10, 11.

[0037] The design of the insert 9 will be explained below with the aid of Figure 2 the perspective view of Fig. 1. The two legs 10, 11 are connected to one another at the end of their back sides in the longitudinal direction by a back 12. Unlike previously known inserts of this type, the back 12 does not extend straight, but in the embodiment shown is characterised by an end-side straight section, a concavely embodied section connected thereto and an intermediate section which is convexly profiled towards the web 7 of the beam 2. The legs 10, 11 also extend non-uniformly in the longitudinal extension of the insert 9. Their width varies in the longitudinal extension of the insert 9. The back 12 is embodied not only non-uniformly in its longitudinal course in the longitudinal extension thereof, but also differently in its height (extension in the z direction). In the intermediate section, the height of the insert 9 is less than in the sections adjoining it on both sides.

[0038] The structural division of the insert 9 can be seen more clearly from the longitudinal section according to Fig. 2. Figure 3 The insert 9 comprises a central section 13. This section is that section in which the back 12 is convexly profiled towards the vehicle chassis and thus protrudes. The central section 13 transitions accordingly into transition sections 14, 14.1, on which one end section 15 is connected respectively. The back 12 of the embodiment shown is embodied straight in the region of its end sections 15, 15.1 and extends in these sections parallel or approximately parallel to the web 7 of the beam 2. In the transition sections 14, 14.1, the insert 9 is embodied waisted, whereby its cross-sectional area is significantly reduced, more precisely in the embodiment shown to approximately 50%. The waisting is concavely profiled into the transition sections 14, 14.1 by the back 12 and likewise concavely profiled towards the leg end of the closing plate 3 (in the longitudinal direction of the insert 9). The end sections 15, 15.1 are embodied straight and extend parallel to the web 7 of the beam 2. Figure 3The leg ends of the insert 9 facing the closure panel 3 are also profiled in the central section 13 in such a way that they do not lie on the inner side of the closure panel 3 over the entire extension. In the embodiment shown, the leg ends lie on the inner side of the closure panel 3 in three sections of the central section 13. In these sections, which are also referred to as connection sections 16, the leg ends of the legs 10, 11 are connected to the inner side of the closure panel 3 by means of a weld seam. The connection sections 16 are arranged at a distance from one another in the longitudinal extension of the insert 9 with respect to one another. The leg ends of the insert 9 between the connection sections 16 do not touch the inner side of the closure panel 3. These sections are also concavely profiled, whereby the leg ends are at a distance from the inner side of the closure panel 3.

[0039] In addition to the connection points 13 of the central section 6, the insert 9 is also connected to the closure panel 3 by means of a weld via the leg ends of the end sections 15, 15.1.

[0040] As can be seen from Figure 2 The central section 13 is additionally structured in that the central region of the central section 13 has a smaller back height than in the adjoining sections.

[0041] Figure 4 A longitudinal section of a bumper beam 1.1 is shown, which corresponds to the bumper beam 1 of the previous figures, with the exception of the profile of the leg ends of the insert 9.1 thereof. In this respect, the explanations for the bumper beam 1 apply equally to the bumper beam 1.1. The insert 9.1 has only two connection points 16.1 in its central section 13.1. A third connection point 16, which is located between the two outer connection points 16 of the insert 9, is not provided in the insert 9.1. In this embodiment, the entire central section between the two connection points 16.1 does not touch the inner side of the closure panel 3 and is concavely shaped over this length.

[0042] The bumper beams 1, 1.1 described above are significantly improved in terms of their crash behavior compared to conventional bumpers in which the insert is embedded in the beam, but does not have the structuring of the insert 9 or 9.1.

[0043] Figure 5 In correspondence with Figure 3The diagrammatic illustration of the diagram shows the bumper beam 1 in front of an obstacle H. The bumper beam 1 is moved in the x-direction towards the obstacle H. This particular design of the insert piece 9 is such that the bumper beam 1 is arranged around the obstacle H, but does not form a crack or even breaks. The reason for this is the particular design of the insert piece 9, by means of which a bending or rather a deformation abutment is provided on the tensile side (the side facing the vehicle chassis) by the convex implementation of the central section 13 and by the material predefinition existing in the transition section 14, 14.1 due to the convex shaping. For this reason, the back 12 of the insert piece 10 can absorb or rather withstand significantly higher tensile forces than a conventional bumper beam.

[0044] Figure 6 The bumper beam 1 is shown after a deformation of approximately 260 mm, which has been absorbed without a crack by deforming the bumper beam 1, as is shown in Figure 6 Here, the concave recess on the compression side on the side of the closing plate serves as a predefined bending or rather bending point.

[0045] For comparison, Figure 7 A bumper beam 17 is shown with a conventional insert piece 18, which has the same cross-sectional geometry over the entire longitudinal extension. It is clearly visible in the diagram that the bumper beam 17 has broken at the same deformation that the bumper beam 1 according to the application has absorbed without any problems. Figure 6

[0046] By the measures described, the efficiency of the crash performance in the bumper beam according to the application is significantly increased, more precisely by approximately 30% to 40% in the embodiment shown. The bumper beam 1 has a weight of 2.5 kg, in general approximately 20 to 30% less, compared to the bumper beam 17 according to the prior art. The energy absorbed in the deformation shown is approximately 2.6 kJ / kg. In the bumper beam 17 shown in Figure 7 only 2.0 kJ / kg can be absorbed. The lower mass and the higher energy absorption result in a significantly increased efficiency.

[0047] Figure 8 Another bumper beam 20 is shown, which is constructed in principle like the already described bumper beams 1 or 1.1. In this respect, the explanations relating thereto apply equally to the bumper beam 20. Only the distinguishing features are discussed below. In comparison with the bumper beams 1 or 1.1, the bumper beam 20 is distinguished in that it also has a plurality of bending abutments. In the embodiment shown, not only the closing plate 21 but also its insert piece 22 (see Figure 9 ​) and also the beam 23 thereof have such a structure. The bend-on structure is a structural component of the bumper beam 20, which serves to promote the bending of the bumper beam and thus to improve the bumper beam's tight or close adherence to the profile of a post (pillar) in the event of energy absorption, for example within the framework of a column test, in the location of these structures.

[0048] The beam 23 of the embodiment shown has two different constructed bend-on structures. On the one hand, the beam 23 has a bend-on rib 24 in each of its two legs centrally with respect to its longitudinal extension, which presses the front-side end of the leg. On the other hand, the beam 25 has a notch as a bend-on structure.

[0049] The closing plate 21 also carries bend-on structures in the embodiment shown, which are arranged mirror-symmetrically with respect to the center with respect to the longitudinal extension of the closing plate 21. These are bend-on ribs that extend in the vertical direction, the pressing direction of which is implemented toward the beam 23. There are two bend-on ribs 24.1 that extend in the vertical direction in the center of the closing plate 21, which press the upper and lower terminal ends. Adjacent to these individual ribs that are cut out at the free ends of the closing plate 21, there is one bend-on rib each that is arranged in the middle section with respect to the vertical direction of the closing plate 21 at a distance along the longitudinal axis. Also at a distance from these, there is a bend-on rib that extends in the vertical direction and is also cut out at the end side at the location where the notch 25 is arranged in the beam 23. The bend-on ribs of the closing plate 21 do not extend over the entire height of the closing plate 21.

[0050] In Figure 11 The insert 22 shown separately in Fig. 2 comprises a central section and two transition sections connected to the central section toward the respective end, followed by an end section, like the previously described inserts 13, 13.1. The transition sections of the insert 22 are also implemented as a waist in their back formation and in the formation of the free end of their leg, as described for the inserts 13 or 13.1. In addition, the insert 22 has bend-on ribs 26, 26.1, wherein each leg of the insert 22 carries two bend-on ribs 26 or 26.1 arranged at a longitudinal axial distance from one another. The bend-on ribs 26, 26.1 are arranged mirror-symmetrically with respect to the center of the insert 22 with respect to its longitudinal extension. The bend-on ribs 26, 26.1 are implemented as positive structures, thus extending in the z direction outwardly from the insert 22 with respect to their pressing direction. The bend-on ribs 26, 26.1 have their greatest pressing depth at the respective leg end. The bend-on ribs 26, 26.1 extend up to the back of the insert 22 and end before the transition of the leg to the back. As can be seen from the sectional view in Fig. 2, the bend-on ribs 26, 26.1 are arranged in the middle section of the insert 22, which is located between the transition sections of the insert 22. Figure 12It can be seen that the bent-on ribs 26, 26.1 are arranged in the two legs in alignment with one another in the z direction.

[0051] From Figure 12 It also becomes clear from the front view of the insert 22 that the central section is reduced in the vertical direction (z direction) in the region of the intermediate section compared to the adjacent sections of the central section in the z direction.

[0052] Figure 10 A further bumper beam 20.1 is shown in which the closure panel 21.1 is removed half in order to see its beam 23.1. The bumper beam 20.1 differs from the bumper beam 20 only in its insert 22.1 which has a greater longitudinal extension than the insert 22 of the bumper beam 20. In this bumper beam, the beam 23.1 and the closure panel 21.1 are the same components as in the bumper beam 20.

[0053] The insert 22.1 of the bumper beam 20.1 is shown separately in a perspective view in Figure 13 It ultimately is identical to the insert 22, so that the explanations relating thereto apply equally to the insert 22.1. The insert 22.1 differs from the insert 22 only in the extension of its end section 27 which is in turn divided into two sections 28, 28.1. The first section 28 of the end section 27 adjoins the transition section between the central section and the end section 27. The further section 28.1 of the end section 22 is in turn spaced apart from the outermost, shorter end section 28.1 by a transition section 29. The transition section 29 between the two sections 28, 28.1 of the end section 27 is configured in exactly the same way in terms of the contour of the back and the shearing of the legs as the transition section between the end section 27 and the central section. The end sections 27 of the insert 22.1 opposite one another are configured identically.

[0054] Figure 15 The bumper beam 20 is shown in a longitudinal section. It can be clearly seen that the convex shaping of the backside slats facing the beam 23 in the central section of the insert 22 in the longitudinal extension direction of the insert 22. The bent-on ribs 26.1 can also be seen in this illustration. The apexes of the bent-on ribs 26.1 are offset rearward relative to the end of the leg facing the closure panel 21, so that in the middle region of the bent-on ribs 26.1, these do not lie against the closure panel 21. The bent-on structure provided by the bent-on ribs 26.1 is thus additionally determined by the material recess. The same applies to the bent-on ribs 26 of the other leg of the insert 22. The insert 22 is connected with its legs to the closure panel 21 at a connection section marked with the reference numeral 30 by a welded connection.

[0055] Figure 16 is shown in a longitudinal section. It can be clearly seen that the convex shaping of the backside slats facing the beam 23 in the central section of the insert 22 in the longitudinal extension direction of the insert 22. The bent-on ribs 26.1 can also be seen in this illustration. The apexes of the bent-on ribs 26.1 are offset rearward relative to the end of the leg facing the closure panel 21, so that in the middle region of the bent-on ribs 26.1, these do not lie against the closure panel 21. The bent-on structure provided by the bent-on ribs 26.1 is thus additionally determined by the material recess. The same applies to the bent-on ribs 26 of the other leg of the insert 22. The insert 22 is connected with its legs to the closure panel 21 at a connection section marked with the reference numeral 30 by a welded connection. Figure 15The same illustration of the bumper beam 20 is reproduced for the bumper beam 20.1. The above explanations for the bumper beam 20 apply equally to the bumper beam 21. Due to the greater length of the insert 22.1, this is additionally connected to the closing plate 21.1 in its outer end section 28.1 in addition to the connection sections 30.1 at which the insert 22.1 is connected to the closing plate 21.1 at the same points as the insert 22 of the bumper beam 20. These sections 28.1 thus also provide a connection section 30.1 with their front-side end termination of the leg.

[0056] Figures 17a to 17c The sequence visualizes the deformation behavior of the bumper beam 20 at the time of the column test. Figure 17a The initial deformation of the bumper beam 20 in the region of its center is shown. The buckling behavior is defined by the buckling abutment structure in the central section located in the middle of the bumper beam 20. If the post further intrudes into the bumper beam 20 towards the vehicle, the central section in the middle deforms further. In addition, a buckling site occurs at the transition section located between the central section and the end section, as can be seen in Figure 17b . Figure 17c The bumper beam 20 is shown tightly clinging to the post 31 (column) with a very uniform profile. It can be seen that the bumper beam 20 clings or rather abuts to the obstacle, which in this case is the post 31, particularly uniformly.

[0057] List of reference signs 1.1 bumper beam 2 beam 3 closing plate 4, 4.1 crash box 5 leg 6 leg 7 lath 8 chamber 9, 9.1 insert 10 leg 11 leg 12 back 13, 13.1 central section 14, 14.1 transition section 15, 15.1 end section 16, 16.1 connection section 17 bumper beam (prior art) 18 insert (prior art) 20, 20.1 bumper beam 21, 21.1 closing plate 22, 22.1 insert 23, 23.1 beam 24, 24.1 Bending abutment rib 25 Notch 26, 26.1 Bending abutment rib 27 End section 28, 28.1 Section 29 Transition section 30, 30.1 Connection section 31 Stake

Claims

1. A bumper beam for a vehicle, having a beam (2, 23, 23.1) which extends with its longitudinal axis in the vehicle transverse direction (y direction) and which is open in the driving direction (x direction), the beam having a chamber (8) which is surrounded by an upper leg (5), a lower leg (6) and a web (7) which connects the two legs (5, 6) in the vehicle vertical direction (z direction); having a closing panel (3, 21, 21.1) which spans the beam opening in the vehicle vertical direction (z direction) and which is connected to the legs (5, 6) of the beam (2, 23.1); and having an insert (9, 9.1, 22, 22.1) which is arranged in the chamber (8) of the beam (2), the insert having an upper leg (10), a lower leg (11) and a back (12) which connects the legs (10, 11) at their rearward terminal ends, the open side of the insert facing in the driving direction (x direction) and the legs (10, 11) of the insert being connected to the closing panel (3, 21, 21.1); characterized in that the back (12) of the insert (9, 9.1, 22, 22.1) being shaped at least in its middle section, with respect to its longitudinal extension (y direction), as a convex shape.

2. The bumper beam of claim 1, wherein, the insert (9, 9.1) being arranged centrally with respect to the longitudinal extension of the beam (2, 23, 23.1) in the chamber (8) of the beam (2, 23, 23.1).

3. The bumper beam according to claim 1 or 2, characterized in that the insert (9, 9.1, 22, 22.1) being connected with its legs (10, 11) to the closing panel (3, 21, 21.1) only in individual sections which are spaced apart from one another in the direction of the longitudinal extension of the insert.

4. The bumper beam of claim 3, wherein, the legs (10, 11) of the insert (9, 9.1, 22, 22.1) reaching up to the closing panel (3, 21, 21.1) only in those sections in which the legs are connected to the closing panel and being spaced apart from the closing panel (3, 21, 21.1) in the sections located therebetween.

5. The bumper beam according to one of claims 1 to 4, characterized in that the insert (9, 9.1, 22, 22.1) being arranged with a distance to the legs (5, 6) and the web (7) of the beam (2, 23, 23.1) within the chamber (8) of the beam.

6. The bumper beam according to one of claims 1 to 5, characterized in that the insert (9, 9.1, 22, 22.1) having insert sections (13, 14, 14.1, 15, 15.1, 13.1) which differ in their height, their width, the contour of the leg ends and / or their material thickness in the direction of their longitudinal extension.

7. The bumper beam of claim 6, wherein, the transition from the leg (10, 11) of a first insert section to an adjacent second insert section is embodied differently.

8. The bumper beam according to claim 6 or 7, characterized in that the insert (9, 9.1, 22, 22.1) has one central section (13) and one end section (15, 15.1, 27) as insert sections, wherein the end section (15, 15.1, 27) is separated from the central section (13) by one transition section (14, 14.1) which is an additional insert section having a concave contour of the back (12).

9. The bumper beam of claim 8, wherein, The end section (27) of the insert part (22, 22.1) has two sections (28, 28.1) separated by a concavely embodied back section as transition section (29).

10. The bumper beam according to claim 8 or 9, characterized in that In the one or more transition sections (14, 14.1, 29), the ends of the legs (5, 6) of the insert part (9, 9.1, 22, 22.1) also have a concavely shaped contour.

11. The bumper beam according to claim 9 or 10, characterized in that The legs of the end sections (15, 15.1, 27) and the legs of the respective first sections of the central sections (13, 13.1) are connected to the closing plate (3, 21, 21.1).

12. The bumper beam of claim 11, wherein, The insert part (9) is additionally connected with its legs at the center of its central section (13) to the closing plate (3).

13. The bumper beam according to claim 11 or 12, characterized in that The sections with which the insert part (9, 9.1, 22, 22.1) is connected with its legs to the closing plate (3, 21, 21.1) are the only connection points (16, 16.1) of the insert part (9, 9.1, 22, 22.1) to the closing plate (3, 21, 21.1).

14. The bumper beam according to one of claims 1 to 13, characterized in that The insert part (21, 21.1), the beam (23, 23.1) and / or the closing plate (21, 21.1) have one or more bent abutment structures.

15. The bumper beam of claim 14, wherein, The insert part (22, 22.1), the beam (23, 23.1) and / or the closing plate (21, 21.1) have a plurality of bent abutment structures which are arranged mirror-symmetrically with respect to the center of the respective component with regard to the longitudinal extension of the respective component.

16. The bumper beam according to claim 14 or 15, characterized in that The ends of the legs of the insert part (22, 22.1) facing in the direction of the beam opening have at least one bent abutment rib (26, 26.1) as bent abutment structure, in particular the bent abutment rib is embodied as a positive structure, wherein the bent abutment structures of the two legs are arranged preferably aligned with one another in the vertical direction of the insert part (22, 22.1).

17. The bumper beam of claim 16, wherein, The at least one bent abutment rib (26, 26.1) of the legs of the insert part (22, 22.1) is embodied as a rib which extends before the transition of the leg into the back of the insert part (22, 22.1), with the largest extrusion at the front leg end.

18. The bumper beam according to one of claims 14 to 17, characterized in that The legs of the beam (23, 23.1) have centrally with regard to their longitudinal extension a bent abutment rib (24), in particular the bent abutment rib is embodied as a positive structure.

19. The bumper beam according to one of claims 14 to 18, characterized in that At least one recess (25) is introduced into the front end of at least one of the legs of the beam (23, 23.1).

20. The bumper beam according to one of claims 1 to 19, characterized in that The closing plate (21, 21.1) has at least one bent abutment rib (24.1) as bent abutment structure which extends in the vertical direction, embodied as a negative structure.

21. The bumper beam of claim 20, wherein, The closing plate (21, 21.1) has a plurality of bent abutment ribs (24.1) which extend in the vertical direction, arranged at a distance from one another with regard to their longitudinal extension, mirror-symmetrically with regard to the center of the closing plate (21, 21.1).

22. The bumper beam according to claim 20 or 21, characterized in that Said closing panel (21, 21.1) has a bent abutment rib (24.1) in each of its upper and lower terminal ends, centrally with respect to its longitudinal extension.

23. The bumper beam according to one of claims 1 to 22, characterized in that Said beams (2, 23, 23.1), said closing panels (3, 21, 21.1) and said inserts (9, 9.1, 22, 22.1) are components made of steel slabs.

24. The bumper beam according to one of claims 1 to 23, characterized in that Said inserts (9, 9.1, 22, 22.1) are connected to said closing panels (3, 21, 21.1) by means of fusion bonding, and said closing panels (3, 21, 21.1) are connected to the legs (5, 6) of said beams (2, 23, 23.1) by means of fusion bonding.

Images