Deformation Structure and Pedestrian Protection Device Having a Deformation Structure

Abstract

A deformation structure has at least a first layer and a second layer, which are spaced apart from each other and are mounted to be movable relative to each other in the deformation direction or load direction. The first layer and the second layer have complementary protrusions and recesses, which are designed such that the protrusions of the first layer can dip into the recesses of the second layer and vice versa. The first layer and the second layer are connected to each other by deformable connecting pieces such that, in the event of a high impulse in the deformation direction, the protrusions of the first layer dip into the recesses of the second layer and the protrusions of the second layer dip into the recesses of the first layer such that the deformation structure is deformed in the deformation direction at a relatively low level of force and, in the event of a low impulse in the deformation direction, the protrusions of the first layer hit the protrusions of the second layer such that the deformation structure is deformed further in the deformation direction at a relatively high level of force. The deformation control device is formed or produced separately from the first and the second layer and is removably or non-removably connected to the first layer and the second layer.

Claims

1.-20. (canceled)

21. A deformation structure, comprising: at least one first layer and a second layer, which are arranged spaced apart from one another and so as to be displaceable with respect to one another in a deformation direction, wherein the first layer and the second layer have complementary protrusions and depressions, which are formed such that the protrusions of the first layer and the depressions of the second layer and also the protrusions of the second layer and the depressions of the first layer can enter into one another; a deformation control device by which the first layer and the second layer are connected to one another in such a way that, in case of a high impulse in the deformation direction, the protrusions of the first layer enter into the depressions of the second layer and also the protrusions of the second layer enter into the depressions of the first layer, whereby a deformation of the deformation structure in the deformation direction takes place at a low level of force, and in such a way that, in case of a low impulse in the deformation direction, the protrusions of the first layer impinge on the protrusions of the second layer, whereby deformation of the deformation structure in the deformation direction takes place at a high level of force, wherein the deformation control device is formed separately from and is connected detachably or non-detachably to the first layer and the second layer.

22. The deformation structure according to claim 21, wherein at least one of: the deformation control device is connected to the first layer and/or the second layer via a clip connection, the deformation control device is adhesively bonded to the first layer and/or the second layer, or the deformation control device is pressed together with the first layer and/or the second layer.

23. The deformation structure according to claim 21, wherein the deformation control device is an injection-molded part.

24. The deformation structure according to claim 21, wherein the deformation control device has a plurality of elastically deformable control webs, which webs connect the first and second layers to one another.

25. The deformation structure according to claim 24, wherein at least two deformation control devices are provided, and the two deformation control devices are arranged at opposite ends of the first layer and the second layer and are connected to the first layer and the second layer.

26. The deformation structure according to claim 21, wherein the first layer and the second layer are each formed in one piece as an injection-molded part.

27. The deformation structure according to claim 21, wherein the first layer and the second layer are each formed in one piece as a deep-drawn component.

28. The deformation structure according to claim 21, wherein the first layer and the second layer are each formed in one piece as an extruded profile.

29. The deformation structure according to claim 21, wherein the protrusions of the first layer and/or of the second layer have a surface that has been modified by a friction-increasing measure.

30. The deformation structure according to claim 29, wherein the protrusions of the first layer and/or of the second layer have increased roughness and are corrugated.

31. The deformation structure according to claim 21, wherein at least one protrusion of the first layer and at least one protrusion of the second layer have a complementary form to one another in such a way that a form fit between the protrusion of the first layer and the protrusion of the second layer is produced at least in a lateral direction in the case of the low impulse in the deformation direction.

32. The deformation structure according to claim 31, wherein the protrusion of the second layer or the protrusion of the first layer has a depression, which is adapted in such a way that the protrusion of the first layer or the protrusion of the second layer can engage into the depression, such that a movement of the first layer and the second layer in relation to one another is inhibited at least in the lateral direction.

33. The deformation structure according to claim 31, wherein the protrusion of the second layer and/or the protrusion of the first layer have/has a step, which is adapted in such a way that the protrusion of the first layer and/or the protrusion of the second layer can engage with the step, such that a movement of the first layer and the second layer in relation to one another is inhibited at least in the lateral direction.

34. The deformation structure according to claim 21, wherein the first layer and the second layer are displaceable in a direction parallel to one another by deformation of the deformation control device.

35. The deformation structure according to claim 21, wherein the deformation control device undergoes brittle and/or plastic failure in the case of the high impulse, and the deformation control device is reversibly elastically deformable in the case of the low impulse.

36. The deformation structure according to claim 21, wherein the protrusions of the first layer and the depressions of the second layer and also the depressions of the first layer and the protrusions of the second layer are arranged opposite one another in a starting position of the deformation structure.

37. The deformation structure according to claim 21, wherein the deformation structure has an odd number of layers, wherein two adjacent layers in each case form a first layer and a second layer.

38. The deformation structure according to claim 37, wherein the deformation structure has exactly three layers, corresponding to a first layer, a second layer and a further layer that substantially corresponds to the first layer.

39. The deformation structure according to claim 37, wherein the deformation control device is configured in such a way that adjacent layers are displaceable in opposite directions in the case of the low collision impulse.

40. A pedestrian protection device for a motor vehicle, comprising: a deformation structure according to claim 21, wherein the deformation structure is arranged between a bumper cladding and a bumper crossmember.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0070] FIG. 1 schematically shows a perspective view of a deformation structure according to a first exemplary embodiment of the present invention.

[0071] FIG. 2 schematically shows a perspective view of a left-hand and a right-hand deformation control device according to the first exemplary embodiment of the present invention.

[0072] FIG. 3 schematically shows a side view of the deformation structure according to the first exemplary embodiment of the present invention in a collision load case with a low collision impulse.

[0073] FIG. 4 schematically shows a side view of the deformation structure according to the first exemplary embodiment of the present invention in a collision load case with a high collision impulse.

[0074] FIG. 5 schematically shows a perspective view of a deformation structure according to a second exemplary embodiment of the present invention.

[0075] FIG. 6 schematically shows a side view of the deformation structure according to the second exemplary embodiment of the present invention in a starting position.

[0076] FIG. 7 schematically shows a side view of the deformation structure according to the second exemplary embodiment of the present invention in a collision load case with a low collision impulse.

[0077] FIG. 8 schematically shows a side view of the deformation structure according to the second exemplary embodiment of the present invention in a collision load case with a high collision impulse.

[0078] FIG. 9 schematically shows a perspective view of a deformation structure according to a third exemplary embodiment of the present invention.

[0079] FIG. 10 schematically shows a side view of the deformation structure according to the third exemplary embodiment of the present invention in a starting position.

[0080] FIG. 11 schematically shows a side view of the deformation structure according to the third exemplary embodiment of the present invention in a collision load case with a low collision impulse.

[0081] FIG. 12 schematically shows a side view of the deformation structure according to the third exemplary embodiment of the present invention in a collision load case with a high collision impulse.

DETAILED DESCRIPTION OF THE DRAWINGS

[0082] Exemplary embodiments of the present invention will be described below with reference to FIGS. 1 to 10.

[0083] A first exemplary embodiment of the invention will be explained with reference to FIGS. 1 to 4.

[0084] FIG. 1 shows a perspective view of a deformation structure 1 according to the first exemplary embodiment of the present invention in a starting position. The deformation structure 1 is mounted on a front face of a motor vehicle front end, in particular on a motor vehicle front, in front of a bumper crossmember, which is not shown, instead of a known pedestrian protection foam. In particular, the deformation structure 1 is arranged in a space between a vehicle outer skin, that is to say a bumper cladding, and the bumper crossmember.

[0085] As is shown in FIG. 1, the deformation structure 1 has exactly three layers 3, 5, 3 arranged one behind the other. The layers 3, 5, 3 are spaced apart from one another and connected to one another at opposite sides of the layers 3, 5, 3 via two deformation control devices 7. The layer 3 that is at the bottom in FIG. 1 has fastening means in the form of clips 39 in order to fasten the deformation structure 1 in a form-fitting and positionally fixed manner to a front side or outer side of the bumper crossmember. For this purpose, corresponding openings for inserting the clips 39 are provided in the bumper crossmember. In principle, the deformation structure 1 may also be fastened to the bumper crossmember via a screw connection, an adhesive bond or another connection.

[0086] The two deformation control devices 7 are illustrated in FIG. 2 in a perspective view without the layers 3, 5, 3. The deformation control device 7 is connected fixedly in a form-fitting manner to each layer 3, 5, 3 at multiple points, i.e. in this exemplary embodiment three points, via clips 75. Each deformation control device 7 has three control webs 71 per layer pair. The control webs 71 have an oblique or arcuate form in such a way that the control webs 71 display a hinge action in a certain direction depending on a collision load or a collision impulse. The control webs 71 run in each case between two oppositely situated fastening webs 73. The control webs 71 between the top layer 3 and the middle layer 5 are formed counter to the control webs 71 between the middle layer 5 and the bottom layer 3, with the result that their hinge actions point in opposite directions. Each fastening web 73 is assigned one of the layers 3, 5, 3. Three clips 75 for engaging with a corresponding opening in the associated layer 3, 5, 3 are arranged on each fastening web 73. The clips 75 have resilient protrusions for engaging behind the opening. Each deformation control device 7 is manufactured in one piece by plastic injection molding. The deformation control device 7 may also have more or fewer control webs 71. This also depends in particular on the dimensions of the layers 3, 5, 3 and/or of the deformation structure 1. More than three layers, preferably an odd number of layers, is also possible. Correspondingly, in this case, the deformation control device has a corresponding number of fastening webs. The hinge action of the control webs runs in this case in opposite directions for each adjacent layer pair.

[0087] FIG. 3 shows a side view of the deformation structure 1 without illustrating the deformation control devices 7, a deformation direction D of the deformation structure 1 in FIG. 3 running from top to bottom and being illustrated by an arrow. The deformation direction D is a vehicle longitudinal direction in this case. A transverse direction in the plane of the drawing corresponds to a vehicle transverse direction. The deformation structure 1 has its deformation function in the deformation direction D. FIG. 3 shows an already-deformed state that was caused by a low collision impulse. The layers 3, 5, 3 have an at least similar construction. A first layer 3 from the top consists of alternating protrusions 31 and depressions 32. Similarly, the second layer 5 from the top consists of alternating protrusions 51 and depressions 52. This is adjoined by a further layer 3, which is formed for fastening to the bumper crossmember, which is not shown, and likewise has protrusions and depressions that are assigned to corresponding protrusions and depressions of the middle layer 5.

[0088] The layers 3, 5, 3 according to the first exemplary embodiment are produced separately from one another by means of plastic injection molding, as a result of which the layers 3, 5, 3 can be produced cost-effectively and can have a sufficiently lightweight form.

[0089] With reference to FIGS. 3 and 4, a function of the deformation structure 1 is illustrated for different collision load cases. In the event of a frontal collision of the motor vehicle with an object or a person, a load, or at least a resultant of a collision load, acts in the vehicle longitudinal direction, i.e. in the deformation direction D, on the deformation structure 1, the frontmost layer 3 (the top layer in the figures) being displaced in the direction of the middle layer 5 with elastic deformation of the control webs 71. The middle layer 5 is also displaced in the direction of the rear layer 3 (the bottom layer in the figures). In the starting position of the deformation structure 1, which is shown in FIG. 1, the protrusions 31 of the layers 3 and the depressions 52 of the layers 5 and also the depressions 32 of the layers 3 and the depressions 51 of the layers 5 are situated opposite one another. If the layers 3 and the layers 5 were not connected to one another via the control webs 71, it would be possible for adjoining layers 3, 5 to be displaced from this starting position toward one another and into one another substantially unimpeded with only low resistance.

[0090] FIG. 3 shows the collision load case with the low collision impulse, which takes place for example at a collision speed of the motor vehicle of under a predefined collision speed of 20 km/h and which is less relevant for pedestrian protection. FIG. 4 shows a collision load case with a high collision impulse, which takes place for example at a collision speed of the motor vehicle of equal to or above the predefined collision speed of 20 km/h. The predefined collision speed is mentioned here merely by way of example and may also have a different value.

[0091] First of all, a function of the deformation structure 1 will be described for the collision of the motor vehicle at a collision speed of less than 20 km/h with reference to FIG. 3.

[0092] The control webs 71 are arranged and configured such that, in the case of the low collision impulse, the adjacent layers 3, 5 undergo a pivoting movement in relation to one another while being pressed in a direction toward one another. Since the bottom layer 3 is fixed to the bumper crossmember and the top layer 3 is also substantially positionally fixed by the action of force during the collision, only the middle layer 5 can move and be displaced in a parallel manner in the direction P, which is predefined by the control webs 71. The control webs 71 act here for example like what are known as film hinges, which assist the pivoting movement and/or define the pivoting path. With this pivoting movement, in addition to the movement toward one another a parallel displacement of the adjacent layers 3 and 5 in relation to one another takes place. Here, the protrusions 31 of the layers 3 pass into a position opposite to the protrusions 51 of the layers 5, until the upper sides or end faces of the protrusions 31 of the layers 3 come into contact with the upper sides or end faces of the protrusions 51 of the layers 5 (the state shown in FIG. 3). In this respect, the upper sides or the end faces of the protrusions 31 and 51 may be configured in such a way that a further parallel displacement of the layers 3 and 5 in relation to one another is made more difficult. For example, the protrusions 31 and 51 may be provided with a friction-increasing measure, for example a corrugation.

[0093] In this way, in the case of the slow collision speed and therefore the low collision impulse, depending on the level of collision load, the deformation structure 1 transmits the collision load in the state of FIG. 3 directly to a structure of the motor vehicle situated behind, i.e. the bumper crossmember, or the individual layers 3, 5, 3 of the deformation structure 1 undergo brittle failure by breaking after the protrusions 31, 51 impinge on one another and/or undergo failure by plastic deformation at a higher level of load than at the quicker collision speed. The deformation structure 1 is preferably designed such that it does not undergo failure and thus a depth to which a collision counterpart penetrates remains low. The penetration depth of the obstacle or the counterpart vehicle is in this case initially smaller as a result of the low deformation of the deformation structure and what are known as crash boxes, via which the bumper crossmember is connected to longitudinal members (engine mounts) of the body, can sufficiently absorb collision energy. Overall, this makes it possible to keep damage to the motor vehicle sufficiently low.

[0094] In particular, the deformation structure 1 may be designed in such a way that it can transmit a collision load to the crash structure without failure of the deformation elements 3 at collision speeds of less than 4 km/h, for example. That is to say that the control webs 7 are merely elastically deformed and the structure of the layers 3 and 5 itself does not undergo failure. This is advantageous if, in the event of what are known as parking knocks or the like, the intention is for no damage to the motor vehicle that requires repair to occur, and influences for example an insurance classification of the motor vehicle. The deformation structure 1 elastically moves back into its starting position after the parking knock by virtue of the elastic restoring force of the deformation control devices 7. At collision speeds from 4 km/h up to approximately 20 km/h, the collision energy is high enough that the crash boxes have to absorb collision energy by deforming, the collision load being transmitted to the crash boxes via the bumper crossmember by way of the position of the deformation structure 1 shown in FIG. 3 (as far as possible without further deformation). The damage to the front face of the motor vehicle front end can, however, be kept relatively low overall by virtue of the low penetration depth mentioned.

[0095] A function of the deformation structure 1 in the event of the collision of the motor vehicle at the collision speed of equal to or greater than 20 km/h will be described below with reference to FIG. 4.

[0096] The control webs 71 are arranged and configured such that, in the case of the high collision impulse, they undergo failure and/or more or less collapse, such that they do not display a hinge action. In this respect, the mass inertia of the layers 3, 5, 3 in the case of the high collision impulse is in particular high enough that the control webs 71 cannot bring about or assist a lateral deflection movement (parallel displacement) of the layers 3, 5, 3 in relation to one another. As a result, the protrusions 31 of the layers 3 and the depressions 52 of the layers 5 and also the protrusions 51 of the layers 5 and the depressions 32 of the layers 3 are moved directly toward one another. In the further course of the collision and deformation of the deformation structure 1, the protrusions 31 of the layers 3 are pushed completely into the depressions 52 of the layers 5. Similarly, the protrusions 51 of the layers 5 are pushed completely into the depressions 32 of the layers 3. Since substantially no deformation of the structure of the layers 3 or the layers 5 is required for this purpose, and only the control webs 71 are deformed, the deformation structure 1 deforms—at least to the state shown in FIG. 4—at a relatively low level of force.

[0097] This is advantageous insofar as it is important, from the collision speed of approximately 20 km/h, for the front face of the motor vehicle front end, and in particular the bumper cladding in conjunction with the deformation structure 1, to react in a sufficiently soft manner in the case of a low level of deformation force in order to protect a pedestrian. The front face then acts in a similarly soft manner to when there is an arrangement of known pedestrian protection foam instead of the deformation structure according to the invention. Accordingly, if the collision counterpart is a pedestrian, a relatively low force advantageously acts on the pedestrian at a speed of approximately 20 km/h and more.

[0098] Overall, the deformation structure 1 according to the invention consequently makes it possible to resolve a conflict of objectives, which firstly at very low collision speeds that are not relevant for pedestrian protection allows sufficiently great stiffness of the deformation structure 1 and/or a sufficiently great level of deformation force of the deformation structure 1 and/or a sufficiently great transmission of force to the structure situated behind with the bumper crossmember in the crash boxes, and at a somewhat higher collision speed that is relevant for pedestrian protection ensures sufficient pedestrian protection by means of a low level of deformation force.

[0099] FIGS. 5, 6, 7 and 8 show a deformation structure 1 according to a second exemplary embodiment. FIG. 5 shows a perspective view of the deformation structure 1 in a starting position with a deformation control device 7. FIG. 6 shows a side view of the deformation structure 1, the deformation control device 7 not being shown, in the starting position. Analogously to the first exemplary embodiment, the deformation structure 1 according to the second exemplary embodiment has layers 3, 5, 3, which are arranged spaced apart from one another and are connected by means of two deformation control devices 7. The top layer 3 has alternating protrusions 31 and depressions 32. The middle layer 5 has alternating protrusions 51 and depressions 52. The protrusions 31 of the layer 3 have a complementary form to the depressions 52 of the layer 5 in such a way that they can enter into the depressions 52. The protrusions 51 of the layer 5 have a similarly complementary form to the depressions 32 of the layer 3 in such a way that they can enter into the depressions 32. The same also applies between the middle layer 5 and the bottom layer 3.

[0100] Analogously to the deformation structure 1 according to the first exemplary embodiment, the deformation structure 1 according to the second exemplary embodiment is formed to receive a collision load and functions in principle as has already been described with reference to the first exemplary embodiment. The collision load in FIGS. 7 and 8 acts from top to bottom and substantially perpendicularly in relation to mid-planes of the layers 3, 5, 3 in a deformation direction D. FIG. 5 and FIG. 6 show the state of the deformation structure 1 prior to a deformation. FIG. 7 shows a deformation of the deformation structure 1 owing to the collision load with a relatively low collision impulse. In the case of the relatively low collision impulse which is shown in FIG. 7, the control webs 71 cause the layers 3 and 5 to pivot in relation to one another, with the result that the protrusions 31 of the layers 3 impinge on the protrusions 51 of the layers 5. As already described above with reference to the first exemplary embodiment, in addition to a movement of the layers 3, 5, 3 toward one another, a parallel displacement P of the layers 3, 5, 3 in relation to one another accordingly takes place. In particular, in this respect the middle layer 5 is displaced, since the bottom (rearmost) layer 3 is fastened in a positionally fixed manner to the bumper crossmember and the top (frontmost) layer 3 is substantially positionally fixed by the introduction of load from the collision counterpart.

[0101] FIG. 8 shows a deformation of the deformation structure 1 owing to a collision load with a relatively great collision impulse. In this respect, analogously to the first exemplary embodiment, oppositely situated protrusions 31, 51 and depressions 52, 32 enter into one another in the case of a low deformation force of the deformation structure 1. The deformation structure 1 is accordingly deformed over a certain deformation distance at a low level of force—in other words, the deformation structure exhibits softer behavior from a certain threshold value (e.g. in the event of a collision of the motor vehicle from 20 km/h).

[0102] By contrast with the deformation structure 1 according to the first exemplary embodiment, the layers 3, 5, 3 of the deformation structure 1 according to the second exemplary embodiment are produced from a deep-drawn steel sheet. It is also possible to produce the layers 3, 5, 3 by roll forming or another shaping process. The layers 3, 5, 3 have a shape similar to what is known as a wavy metal sheet or a trapezoidal metal sheet. As can be readily seen in particular in FIG. 5, each layer has a plurality of embossings (beads) 37 and 57 in the transverse direction of the trapezoidal structure, which advantageously increases a resistance of the layers 3, 5, 3 to buckling. The embossings 37, 57 of the layers 3, 5, 3 may also engage in one another when the layers 3, 5, 3 impinge on one another, with the result that a movement of the layers 3, 5, 3 in relation to one another is inhibited. This is advantageous in particular when a collision load acts obliquely on the deformation structure 1. The engagement of the embossings 37 and 57 into one another allows a torque to be transferred and promotes the mutually parallel realignment of the layers 3, 5, 3 to the benefit of a desired function of the deformation structure 1.

[0103] The deformation control device 7 according to the second exemplary embodiment has clips 75, which engage around an edge of the associated layer 3, 5, 3 from either side and thus connect the deformation control device 7 to the layers 3, 5, 3 (by contrast to the first exemplary embodiment, in which the clips 75 engage into a lateral opening in the layers 3, 5, 3). Apart from this, the deformation control device 7 of the second exemplary embodiment has the same construction as the deformation control device 7 of the first exemplary embodiment.

[0104] FIGS. 9, 10, 11 and 12 show a deformation structure 1 according to a third exemplary embodiment. FIG. 9 shows a perspective view of the deformation structure 1 in a starting position with a deformation control device 7. FIG. 10 shows a side view of the deformation structure 1 in the starting position, the deformation control device 7 not being shown. Analogously to the first exemplary embodiment and the second exemplary embodiment, the deformation structure 1 according to the third exemplary embodiment has layers 3, 5, 3 that are arranged spaced apart from one another and are connected by means of two deformation control devices 7. The top layer 3 has alternating protrusions 31 and depressions 32. The middle layer 5 has alternating protrusions 51 and depressions 52. The protrusions 31 of the layer 3 have a complementary form to the depressions 52 of the layer 5 in such a way that they can enter into the depressions 52. The protrusions 51 of the layer 5 likewise have a complementary form to the depressions 32 of the layer 3 in such a way that they can enter into the depressions 32. The same applies for the layer pair of the middle layer 5 and the bottom layer 3.

[0105] Analogously to the deformation structure 1 according to the first exemplary embodiment and the second exemplary embodiment, the deformation structure 1 according to the third exemplary embodiment is formed to receive a collision load and functions in principle as already described with reference to the first exemplary embodiment. As shown in FIGS. 11 and 12, the collision load acts substantially perpendicularly to mid-planes of the layers 3, 5, 3 in a deformation direction D, which corresponds to the vehicle longitudinal direction. FIG. 11 shows a deformation of the deformation structure 1 owing to the collision load with a relatively low collision impulse. In the case of the relatively low collision impulse, the control webs 71 cause the layers 3 and 5 to pivot in relation to one another, with the result that the protrusions 31 of the layer 3 impinge on the protrusions 51 of the layer 5. As already described above with reference to the first exemplary embodiment, in addition to a movement of the layers 3, 5, 3 toward one another a parallel displacement P of the layers 3, 5, 3 in relation to one another accordingly takes place.

[0106] FIG. 12 illustrates a deformation of the deformation structure 1 owing to a collision load with a relatively great collision impulse. In this case, analogously to the first exemplary embodiment and the second exemplary embodiment, oppositely situated protrusions 31, 51 and depressions 52, 32 enter into one another at a low deformation force of the deformation structure 1. The deformation structure 1 is accordingly deformed over a certain deformation distance at a low level of force—in other words, the deformation structure exhibits softer behavior from a certain threshold value (e.g. in the event of a collision of the motor vehicle from 20 km/h).

[0107] By contrast with the deformation structure 1 according to the first exemplary embodiment and the second exemplary embodiment, the layers 3, 5, 3 of the deformation structure 1 according to the third exemplary embodiment are produced from an extruded aluminum profile. This makes it possible to produce the layers cost-effectively and to cut them to the required length. It is also conceivable to produce the layers 3, 5, 3 from aluminum by a different production process. The layers 3, 5, 3 have a trapezoidal shape.

[0108] The deformation control device 7 according to the third exemplary embodiment has clips, which are provided for engagement with associated lateral openings 37, 57 (see FIGS. 10, 11, 12) in the layers 3, 5, 3. In addition, provided in the layers 3, 5, 3 are openings 39, 59 with which spring arms of the clips can engage in a form-fitting manner when the clips are inserted into the openings 37, 57. Openings 39, 59 may be formed by stamping.

[0109] In the third exemplary embodiment, the protrusions 51 of the layers 5 also have steps 55. The protrusions 31 of the layers 3 have complementary depressions 33 or steps 33 to the steps 55. In the event of the collision with the relatively low collision impulse, oppositely situated steps 55 and depressions 33 impinge on one another and form a form-fitting engagement in a lateral direction or transverse direction, as shown in FIG. 11. As a result, the layers 3, 5, 3 remain more stably in the position and an introduction of force onto the bumper crossmember is reliably produced.