Energy absorbing device for a motor vehicle bumper assembly and motor vehicle bumper assembly

Abstract

The invention relates to an energy absorption device for a bumper assembly of a motor vehicle, which has at least one closed cavity, which is formed over the entire longitudinal extension of the energy absorption device from the bumper-side end to the vehicle-side end, wherein at least one supporting element is arranged on the outer wall for supporting on the bumper of the motor vehicle. The invention is characterized in that two supporting elements are arranged on the outer wall for supporting on the bumper of the motor vehicle, the two supporting elements are connected to each other by means of a connecting piece over the entire longitudinal extension of the two supporting elements facing away from the at least one cavity, which longitudinal extension is smaller than the longitudinal extension of the device, wherein the two supporting elements and the connecting piece together with the outer wall form a further cavity extending in the longitudinal extension of the device.

Description

Technical Field

[0001] The invention relates to an energy absorption device for a motor vehicle bumper assembly and to a motor vehicle bumper assembly having at least one such energy absorption device. Background Art

[0002] Energy absorption devices for motor vehicle bumper assemblies are known, for example, from DE 10 2014 101 320 A1, DE 10 2019 108 043 B3 and DE 20 2015 103 827 U1. The first two mentioned documents show bumper assemblies having energy absorption devices in the form of crash boxes arranged between the bumper and the longitudinal beam of the motor vehicle, wherein a support element is provided, which is supported on the one hand on the corresponding crash box and on the other hand on the bumper there. The struts of DE 10 2014 101 320 A1 are constructed as closed hollow profiles or as U-shaped profiles in their longitudinal extension, while the struts of DE 10 2019 108 043 B3 have a cavity, which is constructed transversely to the longitudinal extension of the struts. In both bumper assemblies, such struts are individually connected to both the energy absorption element and the bumper. For this reason, a joining step, such as welding or screwing, is required in order to produce a corresponding connection. In these bumper assemblies, each crash box of the bumper assemblies is assigned exactly one supporting element.

[0003] In contrast, the energy absorption device of DE 20 2015 103 827 U1 has two support elements, which are arranged as plate-shaped elements on the side strips or the upper and lower strips for the energy absorption element. Here, these side strips and the upper and lower strips are designed as hollow profiles for forming an energy transfer element with the two plate-shaped support elements. In order to connect the individual shells with the strips, energy-intensive welding is required, which also requires corresponding welding tools.

[0004] However, the energy absorption devices known from the prior art still need to be improved in terms of rigidity, so that in the event of a crash the energy can be dissipated particularly well by the energy absorption element or converted into deformation energy. Summary of the invention

[0005] The object of the present invention is therefore to improve an energy absorption device for a motor vehicle bumper assembly so that in the event of a collision the energy is introduced particularly well into the energy absorption device or crash box and the energy introduced into the device is converted into deformation energy in an improved manner. Another object of the present invention is to achieve a reduction in components and assembly effort. It is also an object of the present invention to provide a bumper assembly for a motor vehicle which takes these aspects of the energy absorption device into account.

[0006] With regard to the energy absorption device, this object is achieved by an energy absorption device having all the features of the technical solution of the invention. With regard to the bumper assembly, this object is achieved by a bumper assembly having all the features of the technical solution of the invention. Advantageous configurations of the invention are obtained in the technical solution of the invention.

[0007] The energy absorption device for a motor vehicle bumper assembly according to the invention has at least one closed cavity, which is formed over the entire longitudinal extension of the energy absorption device from the bumper-side end to the vehicle-side end. At least one supporting element is arranged on the side wall of the at least one cavity for supporting on the bumper of the motor vehicle. The energy absorption device according to the invention is now characterized in that two supporting elements are arranged on the side wall for supporting on the bumper of the motor vehicle, which are connected to each other by means of a connecting piece over the entire longitudinal extension facing away from the at least one cavity, which longitudinal extension is smaller than the longitudinal extension of the device or the crash box, wherein the two supporting elements and the connecting piece together with the side wall form a further cavity extending in the longitudinal extension of the device.

[0008] By means of the configuration according to the invention of the energy absorbing device, it is now possible to connect two supporting elements to each other additionally via a connecting piece. This ensures that, in the event of a collision, the energy introduced into the energy transfer device in the form of a crash box is introduced particularly well and evenly. At the same time, by means of this configuration according to the invention, it is possible to orient the energy input very specifically in the longitudinal direction of the energy transfer device. As a result, the risk of bending of the energy absorbing device or the crash box in the event of a collision is significantly reduced. According to an advantageous configuration, the supporting element can also be provided with a crimp, in particular a diagonal crimp, in order to further increase the stability of the energy absorbing device.

[0009] According to a first advantageous embodiment of the invention, the two support elements are designed in such a way that they have a greater longitudinal extension in the region of the side walls of the at least one cavity than in the region of the web, so that the further cavity is closed only in sections along the length over the entire longitudinal extension of the device. This embodiment advantageously achieves that the stiffness of the energy transfer device does not become so great by the further cavity that an effective deformation of the energy transfer device is no longer possible in the event of a crash. In particular, this embodiment of the invention makes it possible to individually adapt the deformation characteristics of the device according to the invention by varying the configuration of the further hollow profile that is closed only in sections along the length.

[0010] A particularly advantageous construction of the present invention is the one-piece construction of the energy absorption device or crash box according to the present invention, wherein this one-piece construction is preferably constructed as an extruded profile, particularly preferably as an aluminum extruded profile. In this case, although it is necessary to give the further cavity its final shape, which is closed only in sections along its length, by reprocessing, in particular by sawing, stamping, cutting or the like. However, this configuration of the present invention avoids additional work steps when manufacturing the individual components and joining them together by welding, screwing or the like, thereby providing significantly lower resource consumption and also significantly reducing logistics costs. In addition, it should be noted here that the energy absorption device must be matched to the corresponding bumper and chassis connection area by reprocessing at its ends after extrusion.

[0011] According to another advantageous embodiment of the invention, the vehicle-side connecting edge of the at least one support element extending between the side wall and the connecting piece forms an angle of α<45°, preferably α<30° with the side wall of the at least one cavity. This embodiment of the invention advantageously makes it possible to adapt the support element in a simple manner to corresponding features of the bumper assembly and the motor vehicle in which the support element is to be used.

[0012] The object of the embodiment of the invention is in the same direction, according to which the vehicle-side connecting edge of at least one supporting element extending between the side wall and the connecting piece extends in a straight line. Optionally, the vehicle-side connecting edge of at least one supporting element extending between the side wall and the connecting piece can also be designed to be curved. Such a straight or curved course can be realized particularly easily by sawing, cutting or punching.

[0013] According to a further embodiment of the invention, it can also be provided that a vehicle-side connecting edge of at least one supporting element extending between the side wall and the connecting web extends as far as the vehicle-side end.

[0014] Alternatively, it is also possible for a vehicle-side connecting edge of at least one supporting element, which extends between the side wall and the connecting web, to be designed in such a way that it contacts the side wall between the bumper-side end and the vehicle-side end.

[0015] By virtue of the above-described corresponding possibilities for deformation of the connecting edge of at least one supporting element, the deformation properties and the energy input properties of the energy absorption device can advantageously be adapted particularly well to the respective motor vehicle or the respective bumper assembly.

[0016] According to another concept of the present invention, a connecting element is arranged or can be arranged on the bumper side end and the vehicle side end so that the device is connected to the bumper on the bumper side end and to the chassis of the motor vehicle, especially the longitudinal beam of the motor vehicle, on the vehicle side end. This connecting element can be integrally constructed with the energy transfer device or the crash box in a subsequent molding step or reprocessing step after the extrusion of the energy absorption device. Of course, this connecting element in the form of a separate flange can also be connected to the energy transfer device or the crash box, so that it can be connected to the corresponding bumper or chassis or longitudinal beam. Here, the connection can be realized using common joining methods, such as welding, screwing or the like.

[0017] Finally, protection is also intended for a bumper assembly for a motor vehicle, which has a bumper and at least one, in particular two, energy absorption devices or crash boxes of the aforementioned type. In particular, when two energy absorption devices or crash boxes according to the invention are used, it is particularly advantageous in such a bumper assembly if the support elements of the two energy absorption devices or crash boxes point towards the transverse axis of the bumper or towards the longitudinal axis of the respective motor vehicle. This has the advantage that the distance between the two energy absorption devices or crash boxes can be varied, which also allows the collision and deformation behavior and the energy absorption to be particularly well adapted to the respective bumper assembly or the respective motor vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Other purposes, advantages, features and application possibilities of the present invention are derived from the following description of the embodiments with the aid of the accompanying drawings. Here, all described and / or illustrated features constitute the subject matter of the present invention by themselves or in any meaningful combination, regardless of their summary in the technical solution or their reference.

[0019] The accompanying drawings show:

[0020] Figure 1 : A first embodiment of a bumper assembly according to the invention is shown in a top view from above, which has two energy absorption devices or crash boxes according to the invention,

[0021] Figure 2 : This is a top view showing Figure 1 The energy transfer device or crash box on the left,

[0022] Figure 3 :Shown along section AA Figure 2 energy transfer device or crash box,

[0023] Figure 4 :Shown along section BB Figure 2 energy transfer device or crash box,

[0024] Figure 5: Shown along section CC Figure 2 energy transfer device or crash box,

[0025] Figure 6 : A second embodiment of an energy absorption device or crash box according to the invention is shown in a top view from above, and

[0026] Figure 7 : A third exemplary embodiment of an energy absorption device or crash box is shown in a sectional view. DETAILED DESCRIPTION

[0027] Figure 1 1 shows an embodiment of a bumper assembly 3 according to the invention in a top view from above. Embodiments of energy transfer devices or crash boxes 1 and 2 according to the invention are arranged on the bumper assembly 3 at its end regions. In this embodiment, the two energy transfer devices or crash boxes 1 and 2 are designed identically, but are arranged mirror-symmetrically with respect to the transverse axis 17 of the bumper assembly 3 or the longitudinal axis 18 of the vehicle. Due to this consistency, not only the following description of the embodiment of the energy transfer devices or crash boxes 1 and 2 is described. Figure 1 And about the following Figure 2 and 3 All for reference only Figure 1 The energy transfer device or crash box 1 on the left side.

[0028] The energy transmission device or crash box 1 is essentially formed here by a hollow profile, which is formed by two side walls 8 and 22, which connect the upper wall 20 and the lower wall 21 to each other. In the present exemplary embodiment, the hollow profile of the crash box 1 is formed as a two-chamber hollow profile with two cavities 6 and 7, such as in particular by Figure 2 As can be seen, the two cavities are separated from each other by a partition wall 23. Here, the partition wall 23 extends substantially perpendicularly to the side walls 8 and 22 and substantially parallel to the lower wall 21 and the upper wall 20. Here, the crash box 1 is joined at its bumper-side end 4 to the bumper 11 of the bumper assembly 3. Here, the joining can be carried out by means of known connection techniques, such as screwing or welding. A flange 19 is arranged on the vehicle-side end 5 of the crash box 1, by which the crash box 1 can be connected to the chassis or longitudinal beams of the motor vehicle.

[0029] Arranged on the side wall 8 of the crash box 1 facing the crash box 2 are two essentially plate-shaped support elements 9 and 10 which are connected to one another by means of a web 12, such as in particular by Figure 2 Here, the side walls 8 and the connecting piece 12 together with the supporting elements 9 and 10 form a further cavity 14, such as in particular Figure 3It can be seen that the web 12 of the crash box 1 extends in its longitudinal extension 13 only over a part of the longitudinal extension of the crash box 1 . As a result, the supporting elements 9 and 10 each have a connecting edge 15 , 16 , which extends from the vehicle-side end 5 of the crash box 1 to the web 12 . Since the cavity 14 does not extend over the entire longitudinal extension of the actual crash box 1 , it forms an open cavity, whereas the cavities 6 , 7 of the crash box 1 are designed to be continuously closed over the entire longitudinal extension of the crash box 1 .

[0030] Now, in Figure 2 The top view from above shows the Figure 1 Energy absorption device or crash box 1 in the embodiment of the present invention. It is clearly visible here that the extruded profile produced in one piece must be processed again before it can be used as energy absorption device or crash box 1 according to the present invention. For this purpose, a contour matching with the bumper 11 to which the crash box 1 is to be connected must be achieved at the bumper side end 4. In addition, the open cavity 14 must be constructed openly by processing, for example cutting, sawing or punching, wherein the supporting elements 9 and 10 and the connecting edges 15 and 16 are formed. Here, in Figure 3 It is clearly visible in FIG. 8 that, through this reprocessing, the longitudinal extension 13 of the connecting piece is significantly shortened relative to the longitudinal extension of the crash box. In this reprocessing, an angle α is also formed between the connecting edges 15 , 16 and the side wall 8 .

[0031] In the present exemplary embodiment, the extruded profile is processed so that the energy absorption device or crash box 1 produced in this way has supporting elements 9 and 10, which extend from the vehicle-side end 5 of the crash box 1 to the connecting piece 12. In the present exemplary embodiment, the angle α is approximately 25°. In principle, it is also conceivable that the connecting edges 15 and 16 are not guided from the connecting piece 12 to the vehicle-side end 5 of the crash box 1. In other exemplary embodiments, it is possible that these connecting edges 15 and 16 meet the side wall 8 between the vehicle-side end 5 and the bumper-side end 4.

[0032] Now, in Figure 3 Along the Figure 2 The sectional view of the cutting plane AA shows the crash box 1, wherein Figure 1 The flange 19 shown in FIG. 1 is not yet arranged on the crash box 1. The cavity profile of the crash box 1 and its two cavities 6 and 7 separated by the partition wall 23 are clearly visible. The cavity profile of the crash box 1 is formed here by an upper wall 20 and a lower wall 21, which are connected to each other by side walls 8 and 22. The partition wall 23 separating the cavities 6 and 7 extends here perpendicularly to the side walls 8 and 22 and here essentially parallel to the lower wall 21 and the upper wall 20. In the present exemplary embodiment, a plate-shaped supporting element 10 is connected in the region of the upper wall 20, which is essentially perpendicular to the side wall 8. In accordance with Figure 2In the illustration of FIG. 1 , the support element 10 is shown in a top view looking at the connecting edge 15 between the side wall 8 and the connecting piece 12. In the same way, a further support element 9 is connected in the region of the lower wall 21, which also extends to the connecting piece 12 and is connected according to Figure 2 In the illustration of , it is shown towards its connecting edge 16 .

[0033] exist Figure 3 As can be seen from the illustration of , such an energy absorption device or crash box 1 can be manufactured particularly easily as an extruded profile. Here, a special embodiment as an aluminum extruded profile is suitable. Such an extruded profile can be manufactured in one piece particularly easily and in a mature process technology.

[0034] In addition, Figure 4 Along the Figure 2 The sectional view of the section plane BB of FIG. 1 shows the crash box 1. As can be seen therein, in this region, the support elements 9 and 10 are Figure 3 The web 12 which can still be seen in the drawing has been cut out. Only the curved transition region is still present between the support elements 9, 10 and the web which is no longer present. All other elements of the energy absorption device 1 are otherwise identical to those according to Figure 2 The illustration of has not changed. In this respect, only the closed cavity 14 is no longer present. Rather, the cavity is now open in the region of the sectional plane BB.

[0035] Figure 5 It is shown along Figure 2 Here, it is now clearly visible that the transition regions of the support elements 9, 10 to the connecting pieces 12 are no longer present. These transition regions are now also cut out. In this respect, the connecting pieces 9 and 10 are also smaller in this region than in Figure 4 and Figure 3 The closer one approaches the vehicle-side end of the crash box 1 , the shorter the support elements 9 and 10 become, until they completely disappear at the end of the crash box 1 .

[0036] Now, Figure 6 A second embodiment of an energy absorption device or crash box 1 according to the invention is shown in a top view from above. In this embodiment, the support elements 9 and 10 are arranged relative to each other. Figures 1 to 5 The embodiment is changed. Figure 6 The support elements 9 and 10 in the crash box 1 are now not guided to the vehicle-side ends, but only to approximately the middle of the longitudinal extension of the crash box 1. This results in the connecting edges 15 and 16 being significantly shorter than in the first exemplary embodiment. This results in the sectional view along the section plane CC there corresponding to Figure 5 However, Figure 6The cutting plane CC of the embodiment is located at the Figure 2 At the height of the cutting plane BB of the first embodiment.

[0037] exist Figure 7 1 shows a further embodiment of an energy absorption device or crash box 1 according to the invention in a sectional view. In this embodiment, the sectional view in the area of ​​the bumper side can correspond to that of the first embodiment. Figure 3 . By compressing and bending the webs 9 and 10 toward the interior of the cavity 14, the cavity 14 is now reduced in cross section. The cavity 14 is now further reduced from the bumper-side end to the vehicle-side end until it is reduced at the vehicle-side end to such an extent that the webs 9 and 10 are folded over so that they each rest with half their length on the side walls 8 of the cavities 6 and 7 and the web 12. However, in a special embodiment of this embodiment, the web 12 can also be cut out or removed toward the vehicle-side end. This also applies to the supporting elements 9 and 10.

[0038] In other embodiments, it is also possible that the connecting edges 15 and 16 are not designed in a straight line as in the present embodiment, but have a curvature. The exact configuration of the support elements 9 and 10 with their connecting edges 15 and 16 and the connecting piece can be matched to the given conditions of the corresponding vehicle type or the corresponding bumper assembly 3.

[0039] Reference numerals list

[0040] 1Energy absorbing equipment, crash box

[0041] 2Energy absorbing equipment, crash box

[0042] 3 Bumper assembly

[0043] 4 Bumper side end

[0044] 5 Vehicle side end

[0045] 6 Cavity

[0046] 7 Cavity

[0047] 8 Sidewall

[0048] 9 Support elements

[0049] 10 Support elements

[0050] 11 Bumper

[0051] 12 Connecting piece

[0052] 13 Vertical extension

[0053] 14 Cavity

[0054] 15 Connecting Edges

[0055] 16 Connecting Edges

[0056] 17 Horizontal axis

[0057] 18 Longitudinal axis of vehicle

[0058] 19 Flange

[0059] 20 upper wall

[0060] 21 lower wall

[0061] 22 Sidewall

[0062] 23 Divider Wall

Claims

1. An energy absorption device (1, 2) for a bumper assembly (3) of a motor vehicle, comprising at least one closed cavity (6, 7) which is formed over the entire longitudinal extension of the energy absorption device from the bumper-side end to the vehicle-side end (4, 5), wherein: At least one supporting element (9, 10) is arranged on an outer wall (8) of an energy absorption device for supporting on a bumper (11) of a motor vehicle, wherein two supporting elements (9, 10) are arranged on the outer wall (8) for supporting on a bumper (11) of a motor vehicle, wherein the outer wall (8) is an outer wall of the motor vehicle in the inward direction, wherein the ends of the two supporting elements (9, 10) on the side ends of the bumper are supported on the bumper of the motor vehicle, and the two supporting elements are connected to each other by means of a connecting piece (12) over the entire longitudinal extension (13) of the two supporting elements facing away from the at least one cavity (6, 7), which longitudinal extension is smaller than the longitudinal extension of the device (1, 2), wherein the two supporting elements (9, 10) and the connecting piece (12) are connected to each other over the entire longitudinal extension (13) of the two supporting elements facing away from the at least one cavity (6, 7), and ... 2) together with the outer wall (8), form a further cavity (14) extending in the longitudinal extension of the device (1, 2), wherein the support elements (9, 10) become shorter and shorter as they approach the vehicle-side end of the energy absorption device until they completely disappear at the end of the energy absorption device, wherein the two support elements (9, 10) are constructed so that they have a greater longitudinal extension in the area of ​​the outer wall (8) than in the area of ​​the connecting piece, so that the further cavity (14) is constructed to be closed only in sections along the length over the entire longitudinal extension of the device (1, 2), and the device is constructed as an extruded profile, wherein the further cavity (14) obtains its final shape of being closed only in sections along the length by post-processing.

2. The device according to claim 1, characterized in that The device is constructed as an aluminum extruded profile.

3. The device according to claim 1 or 2, characterized in that A vehicle-side connecting edge (15, 16) of at least one supporting element (9, 10) extending between the outer wall (8) and the connecting piece (12) forms an angle α<45° with the outer wall (8) of the at least one cavity (6, 7).

4. The device according to claim 1 or 2, characterized in that A vehicle-side connecting edge (15, 16) of at least one supporting element (9, 10) extending between the outer wall (8) and the connecting piece (12) extends in a straight line.

5. The device according to claim 1 or 2, characterized in that A vehicle-side connecting edge (15, 16) of at least one supporting element (9, 10) extending between the outer wall (8) and the connecting piece (12) is designed to be curved.

6. The device according to claim 1 or 2, characterized in that A vehicle-side connecting edge (15, 16) of at least one supporting element (9, 10) extending between the outer wall (8) and the connecting piece (12) extends as far as the vehicle-side end (5).

7. The device according to claim 1 or 2, characterized in that A vehicle-side connecting edge (15, 16) of at least one supporting element (9, 10) extending between the outer wall (8) and the connecting piece (12) is configured such that the vehicle-side connecting edge contacts the outer wall (8) between the bumper-side end and the vehicle-side end (4, 5).

8. The device according to claim 1 or 2, characterized in that Connecting elements are arranged on the bumper-side ends and the vehicle-side ends (4, 5) in order to connect the device (1, 2) to the bumper (11) at the bumper-side end (4) and to the chassis of the motor vehicle at the vehicle-side end (5).

9. The device according to claim 1 or 2, characterized in that The further cavity (14) is given a final shape by punching and / or cutting, which is closed only in sections along the length.

10. The device according to claim 1 or 2, characterized in that A vehicle-side connecting edge (15, 16) of at least one supporting element (9, 10) extending between the outer wall (8) and the connecting piece (12) forms an angle α<30° with the outer wall (8) of the at least one cavity (6, 7).

11. The device according to claim 1 or 2, characterized in that Connecting elements are arranged on the bumper-side ends and the vehicle-side ends (4, 5) in order to connect the device (1, 2) at the bumper-side end (4) to the bumper (11) and at the vehicle-side end (5) to a longitudinal beam of a motor vehicle.

12. A bumper assembly (3) for a motor vehicle, comprising a bumper (11) and at least one energy absorption device (1, 2) according to any one of the preceding claims.

13. The bumper assembly (3) according to claim 12, characterized in that: It has two energy absorbing devices (1, 2).

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