Deformation Device and Bumper of a Motor Vehicle

Abstract

A deformation device for attaching to a crossmember of a bumper and for converting impact energy onto a lighting device has at least two deformation elements arranged in series and orientated in the same direction. The deformation device also has a support element which can be secured to a crossmember of a bumper, wherein the at least two deformation elements are secured to the support element. Each deformation element has an unstructured, flat surface and is designed such that the deformation elements buckle due to a force acting in a first direction and bend due to a force acting in a second direction.

Claims

1.-10. (canceled)

11. A deformation device for attachment to a crossmember of a bumper and for converting impact energy on a lighting device, comprising: at least two deformation elements arranged in a row and having a same orientation; and a carrier element, which is securable to a crossmember of a bumper, wherein the at least two deformation elements are secured to the carrier element, and each deformation element has an unstructured, smooth surface and is configured such that the deformation elements buckle owing to an action of force in a first direction and bend owing to an action of force in a second direction.

12. The deformation device according to claim 11, wherein each deformation element has a stiffening portion for stiffening against bending and/or buckling.

13. The deformation device according to claim 12, wherein the stiffening portion has a profile with a defined shape within the deformation element.

14. The deformation device according to claim 13, wherein the defined shape is round or angular.

15. The deformation device according to claim 13, wherein the profile of the stiffening portion is arranged and configured such that the stiffening portion has pressure applied to it owing to an action of force in the second direction.

16. The deformation device according to claim 11, wherein each deformation element comprises a first and a second longitudinal side and a first and a second broad side, which are respectively oppositely situated, in order to form a three-dimensionally shaped body with a thickness.

17. The deformation device according to claim 16, wherein the first direction, in which the deformation elements buckle under the action of force, runs in the direction of a connecting line from the first longitudinal side to the second longitudinal side.

18. The deformation device according to claim 17, wherein the second direction, in which each deformation element bends under the action of force, intersects a broad surface of the deformation element.

19. A bumper of a motor vehicle, comprising: at least one deformation device as claimed in claim 11; and a crossmember with a swept profile, wherein the at least one deformation device is secured to the crossmember.

20. The bumper according to claim 19, wherein the crossmember has a first, a second, and a third crossmember portion, the first crossmember portion is oriented transversely with respect to a direction of forward travel of a motor vehicle, and the second and the third crossmember portion form an angle of between 10 and 40 degrees with the first crossmember portion.

21. The bumper according to claim 20, wherein the angle is 30 degrees.

22. The bumper according to claim 19, further comprising: at least one lighting unit, wherein the at least one lighting unit is arranged on a respective deformation device, and the carrier element of the deformation device on which the lighting unit is arranged is secured to the second and/or the third crossmember portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] FIG. 1 is a plan view of a vehicle front with a leg test specimen and a pendulum, and the impact directions thereof on a deformation device according to the invention;

[0039] FIG. 2 shows one of the deformation devices from FIG. 1 in an unloaded state;

[0040] FIG. 3 is a force-time diagram for the deformation device from FIG. 2 for an impact from different directions;

[0041] FIG. 4 shows the deformation device from FIG. 2 in a first loaded state; and

[0042] FIG. 5 shows the deformation device from FIG. 2 in a second loaded state.

[0043] In the following description, the same reference signs are used for the same subjects.

DETAILED DESCRIPTION OF THE DRAWINGS

[0044] FIG. 1 is a plan view of a vehicle front 30 showing a leg test specimen 32 and a pendulum 31, and also the impact directions 6, 7 thereof on a deformation device 1 according to the invention.

[0045] More precisely, FIG. 1 shows a bumper 20 of a motor vehicle having two deformation devices 1 and having a crossmember 21 with a swept profile, wherein the deformation devices 1 are secured to the crossmember 21.

[0046] FIG. 1 also shows that the crossmember 21 has a first, a second and a third crossmember portion 22, 23, 24, wherein the first crossmember portion 22 forms a blunt arrow tip of the swept profile of the crossmember 21.

[0047] Furthermore, the second and the third crossmember portion 23, 24 taper obliquely toward the first crossmember portion 22.

[0048] While the first crossmember portion 22 is oriented transversely with respect to the direction of forward travel X of a motor vehicle, each of the second and third crossmember portions 23, 24 forms an angle of 30 degrees with the first crossmember portion 22.

[0049] FIG. 1 also shows that the bumper 20 has two lighting units 25, each of which is arranged on a deformation device 1, in particular on a second longitudinal side 9 of deformation elements 2, 3, 4 of the deformation device 1. In fact, the deformation device 1 has a multiplicity of deformation elements, but for the sake of simplicity the deformation elements 2, 3, 4 are mentioned by way of example for all of them.

[0050] FIG. 2 shows one of the deformation devices 1 from FIG. 1 in an unloaded state.

[0051] The deformation device 1 for attachment to the crossmember 21 of the bumper 20 and for converting impact energy on a lighting unit 25 has multiple deformation elements 2, 3, 4 arranged in a row and having the same orientation.

[0052] The deformation device 1 also has a carrier element 5, which is secured to the crossmember 21 of the bumper 20, wherein the deformation elements 2, 3, 4 are secured to the carrier element 5.

[0053] Each deformation element 2, 3, 4 has an unstructured, smooth surface and is designed such that the deformation elements 2, 3, 4 buckle owing to an action of force in a first direction 6 (cf. FIGS. 4 and 5, on the left) and bend owing to an action of force in a second direction 7 (cf. FIGS. 4 and 5, on the right).

[0054] In this respect, the first direction 6 is oriented parallel to the deformation elements 2, 3, 4, wherein the second direction 7 causes the deformation elements 2, 3, 4 to bend around the carrier element 5 (cf. FIGS. 4 and 5).

[0055] FIG. 2 also shows that each deformation element 2, 3, 4 has a stiffening portion 12 for the purpose of stiffening it against bending and/or against buckling. In this respect, the stiffening portion 12 has a round profile within the deformation element 2, 3, 4.

[0056] More specifically, the stiffening portion 2 has a gutter-shaped form, similar to an open roof gutter, and is arranged centrally in each deformation element 2, 3, 4.

[0057] Furthermore, the round or gutter-shaped profile of the stiffening portion 12 is arranged and designed such that the stiffening portion 12 has pressure applied to it owing to an action of force in the second direction 7 (cf. FIGS. 4 and 5).

[0058] As FIG. 2 additionally shows, each deformation element 2, 3, 4 has a first and a second longitudinal side 8, 9 and a first and a second broad side 10, 11, which are respectively oppositely situated, in order to form a three-dimensionally shaped body with a thickness.

[0059] The first longitudinal side 8 of the deformation elements 2, 3, 4 is secured to the carrier element 5, such that the deformation elements 2, 3, 4 are oriented perpendicularly with respect to the carrier element 5.

[0060] Also according to FIG. 2, the shape of each deformation element 2, 3, 4 may be similar to a sheet, wherein each deformation element 2, 3, 4 has a width and a length that are greater than a thickness of a deformation element.

[0061] FIG. 4 shows the deformation device 1 from FIG. 1 in a first loaded state, whereas FIG. 5 shows the deformation device 1 from FIG. 1 in a second loaded state.

[0062] It is clear from the two figures that the first direction 6, in which the deformation elements 2, 3, 4 buckle under the action of force of the pendulum 31, runs in the direction of a connecting line from the first longitudinal side 8 to the second longitudinal side 9.

[0063] More specifically, the first direction 6 runs along the shortest connection between the first longitudinal side 8 and the second longitudinal side 9 or parallel to the first or the second broad side 10, 11 of the deformation elements 2, 3, 4.

[0064] It is additionally clear from FIGS. 4 and 5 that the second direction 7, in which each deformation element 2, 3, 4 bends under the action of force, intersects a deformation element 2, 3, 4, in particular its surface. In this respect, the second direction 7 forms an angle of 30 degrees with the surface of the deformation elements 2, 3, 4.

[0065] Lastly, it is noted that the deformation elements 2, 3, 4 comprise plastic or aluminum or a composite substance as material.

[0066] The carrier element 5 and the deformation elements 2, 3, 4 are also formed in one piece.

[0067] With reference to FIGS. 3 to 5, an explanation will be given for the force-time diagram for the deformation device 1 from FIG. 2 for an impact from different directions.

[0068] In this respect, FIG. 4 shows the deformation device 1 from FIG. 2 in a first loaded state and FIG. 5 shows the deformation device 1 from FIG. 2 in a second loaded state, wherein the first loaded state is before the second loaded state in time.

[0069] Whereas the left-hand sides of FIGS. 4 and 5 show the collision of the deformation device 1 with the pendulum 31 from FIG. 1, the right-hand sides show the collision of the deformation device 1 with the leg test specimen 32 from FIG. 1.

[0070] Thus, the right-hand sides of FIGS. 4 and 5 show the behavior of the deformation device 1 when it acts as pedestrian protection and the left-hand sides show the behavior of the deformation device 1 in the event of a pendulum impact.

[0071] In this respect, the pendulum impact simulates e.g. what is referred to as a “parking knock” or an impact of the bumper 21 or the lighting unit 25 in front of the deformation device 1 with another car having a mass of 2700 kg at a speed of 2.7 km/h that occurs when pulling into or pulling out of a parked state.

[0072] By contrast, the impact with a leg test specimen 32 simulates an impact with a pedestrian or their leg having a mass of 14 kg at a speed of 40 km/h.

[0073] The design of the deformation device 1 causes the deformation elements 2, 3, 4 to buckle in the event of a pendulum impact, whereas an impact with the leg test specimen 32 causes the deformation elements 2, 3, 4 to bend.

[0074] FIG. 3 shows, illustratively in a force-time diagram, that the reaction of the deformation elements 2, 3, 4 or the deformation device 1 is different for the impact with the leg test specimen 32 and the pendulum impact.

[0075] With reference to FIG. 3, in the event of a pendulum impact or in the event of a corner pendulum impact at the beginning of the impact, a large amount of force is received, which is then dissipated continuously over the course of the impact by deformation.

[0076] By contrast, different behavior is exhibited in the event of an impact with the leg test specimen 32. Here, at the beginning of the impact a small amount of force is received, and only at a later point in time does more force build up against the leg test specimen 32. Consequently, the deformation device 1 is much more flexible at the start in the event of an impact with the leg test specimen 32 than in the event of a pendulum impact.

[0077] Expressed differently, the deformation device 1 is significantly stiffer for the pendulum impact than for the impact with the leg test specimen 32.

LIST OF REFERENCE SIGNS

[0078] 1 Deformation device [0079] 2 Deformation element [0080] 3 Deformation element [0081] 4 Deformation element [0082] 5 Carrier element [0083] 6 First direction [0084] 7 Second direction [0085] 8 First longitudinal side [0086] 9 Second longitudinal side [0087] 10 First broad side [0088] 11 Second broad side [0089] 12 Stiffening portion [0090] 20 Bumper [0091] 21 Crossmember [0092] 22 First crossmember portion [0093] 23 Second crossmember portion [0094] 24 Third crossmember portion [0095] 25 Lighting unit [0096] 30 Vehicle front [0097] 31 Pendulum [0098] 32 Leg test specimen [0099] F Direction of forward travel