Bumper components

Abstract

The present invention relates to a bumper assembly, which has a crossbeam and two deformation elements for being arranged between an end section of the crossbeam and a longitudinal beam of a motor vehicle, the crossbeam being implemented as a hollow profile having a front wall, a rear wall, an upper wall and a lower wall, the front wall having a groove, which extends in the longitudinal direction of the crossbeam, the groove having a deepest area, which extends at a distance from the rear wall, the upper wall and the lower wall each having at least one further groove in the end area, the further groove extending in the longitudinal direction of the crossbeam, so that the upper wall and the lower wall are more strongly grooved in the end area than in the middle area of ​​the crossbeam, so that the distance between the front wall and the rear wall is smaller in the end area than in the middle area of ​​the crossbeam.

Description

Technical Field

[0001] The invention relates to a bumper assembly. Background Art

[0002] The present invention relates to a bumper assembly having a crossbeam and two deformation elements (crash boxes) for being arranged between the end sections of the crossbeam and the longitudinal beams of a motor vehicle, in particular a passenger car. The crossbeam is implemented as a hollow profile having a front wall, a rear wall, an upper wall and a lower wall. The hollow profile can be manufactured as an extruded part with a single-cavity or multi-cavity cross section (EP2325058A2). This bumper system, which is installed on the front and rear sides of a motor vehicle in accordance with standards for absorbing the collision energy of small collisions, must meet different requirements and collision situations. The crossbeam should be light and flexurally rigid so that the collision force can be introduced into the deformation element. At the same time, the flexural rigidity of the crossbeam should not be too high so that it has the required flexibility in the case of a collision at a higher speed so as to absorb energy by the deformation of the crossbeam. At the same time, the crossbeam will not bend uncontrollably or even tear off from the crash box in the case of high point loads. Summary of the invention

[0003] The object of the present invention is to provide a bumper assembly in which the cross member has both high rigidity in order to better meet the requirements of low-speed impact tests and at the same time has the necessary flexibility in order to better meet the test requirements at higher impact speeds.

[0004] To this end, the present invention proposes a bumper assembly, which has a cross member and two deformation elements for being arranged between an end section of the cross member and a longitudinal member of a motor vehicle, wherein the cross member is designed as a hollow profile with a front wall, a rear wall, an upper wall and a lower wall, the front wall having a groove, which extends in the longitudinal direction of the cross member, the groove extending over the entire length of the cross member, the groove having a deepest area, which extends at a distance from the rear wall, the upper and lower walls each having at least one further groove in the end area, the further groove extending in the longitudinal direction of the cross member, so that the upper wall and the lower wall are more strongly grooved in the end area than in the middle area of ​​the cross member, so that the distance between the front wall and the rear wall is smaller in the end area than in the middle area of ​​the cross member, and the distance between the groove in the front wall and the rear wall is between 5 mm and a maximum of 30% of the depth of the cross member in the middle area measured in the longitudinal direction of the motor vehicle and 5 mm at least in the end area.

[0005] The bumper assembly according to the present invention comprises a crossbeam and two deformation elements (crash boxes). The crash box is arranged between the longitudinal beam of the motor vehicle and the end region of the crossbeam. The crossbeam is implemented as a hollow profile. In particular, it is an extruded single-chamber or multi-chamber profile. In particular, it is a single-chamber profile. The hollow profile has a substantially rectangular cross section and has a front wall, a rear wall, an upper wall and a lower wall. A deep groove is provided in the front wall. The groove extends in the longitudinal direction of the crossbeam. The groove is oriented toward the rear wall and has a deepest area, which extends at a distance from the rear wall. In the upper wall and the lower wall, at least one additional groove is provided in the end region. The additional groove also extends in the longitudinal direction of the crossbeam. The groove in the front wall is preferably open toward the outer end of the end section.

[0006] The additional recesses in the upper and lower walls allow the upper and lower walls to be bent more strongly in the end regions than in the middle region of the cross member. As a result, the distance between the front wall and the rear wall is smaller in the end regions than in the middle region of the cross member. In other words, the depth of the cross member measured in the longitudinal direction of the vehicle is smaller in the end sections because the front wall is closer to the rear wall.

[0007] By reducing the distance between the front wall and the rear wall, the distance from the deepest area of ​​the groove to the rear wall is smaller in the end area. This reduction has a significant effect on the deformation curve. If the crossbeam is too easily deformed in its end area, for example because its upper and lower walls are bent, this leads to the crash box deforming only with a time delay. The time delay can lead to a drop in the force-displacement curve in the force-displacement diagram, in which the force required for deformation is plotted in relation to the penetration depth into the motor vehicle. Therefore, the maximum permissible force as the product of force × displacement and the deformation work generated thereby cannot be utilized in an optimal manner. The object of the present invention is to deform the crash box at an early time before the deformation of the crossbeam ends. For this purpose, the area of ​​the crash box can be provided with a trigger, for example, with a structure that makes the crash box softer in the event of a collision. However, according to the present invention, a different or additional method is selected. The groove in the front wall is a trigger for the crash box. Therefore, the groove is particularly deep in the area of ​​the deformation element, that is, in the area of ​​the upstream end area of ​​the crossbeam. The distance between the front wall and the rear wall is specifically set so that the deepest area of ​​the groove contacts the rear wall of the crossbeam early in the event of a collision. At the same time, the end area must be relatively yielding, which is achieved by the greater curvature of the upper and lower walls. In addition, the groove is configured to be more flexurally rigid than the upper and lower walls so that the collision forces from the front wall can be transferred via the groove to the rear wall. Through the load path via the groove to the rear wall, the crash box is loaded early with higher collision forces, so that the deformation element begins to deform early. As a result, this leads to: the force-displacement characteristic curve has a smaller force drop, because the energy absorption of the crossbeam overlaps with the energy absorption of the deformation element. This means that more deformation work can be performed with a smaller penetration depth or greater collision forces can be absorbed without increasing the penetration depth.

[0008] Another advantage of the bumper system according to the invention is also due to the grooves in the upper and lower walls. The grooves are arranged in the end regions in order to bend the upper and lower walls more strongly there. As a result, the middle region exhibits greater bending rigidity than the end regions. The grooves are partially compressed in a collision that does not occur in the crash box region but in the middle region of the cross member. At the same time, the same grooves in the outer end regions, i.e. at the free ends of the cross member, cause the upper and lower walls to be stretched, thereby increasing the distance between the front wall and the rear wall. These properties of the grooves, which can compensate for compressive stresses and tensile stresses at once, make it possible to rotate the cross member around the inner front edge of the deformation element, i.e. around the region of the crash box that faces the central longitudinal axis of the vehicle. The ends of the cross member are widened in the load case, while the more internal sections of the end region are compressed. Both of these contribute to energy consumption.

[0009] The end section therefore has a relatively high yieldability. On the one hand, in order that in the event of a crash in the region of the deformation element the deep recess contacts the rear wall early and thus initiates the deformation of the crash box. On the other hand, in another load situation, the above-mentioned rotational movement should be possible, in which the outer end of the cross member is widened and the section of the end region arranged toward the transition region is compressed.

[0010] The crossbeam is preferably an extruded profile, in particular a single-chamber profile. The recess in the end region is subsequently produced by deforming the extruded profile. It is possible that the recess in the front wall is finally produced by extrusion. The recess can be deepened afterwards.

[0011] Preferably, the recess in the front wall has a cross section that remains constant over the entire length of the bumper assembly due to manufacturing. The cross member can extend in an arcuate manner to match the configuration of the front end of the motor vehicle, wherein the concave side of the cross member is respectively oriented toward the center of the vehicle. Matching the arcuate rear wall of the cross member, the deformation element has a front side that is matched to the orientation of the rear wall of the cross member. The deformation elements can be matched to the height of the cross member or be designed lower. However, they can also be higher than the cross member and extend beyond or surround the cross member above and / or below.

[0012] The invention includes the extruded profile being a multi-chamber profile. In this case, however, any inner walls in the end regions should be removed so that the deepest region of the recess extends in the end region at the distance from the rear wall. The recess in the end region should not initially, that is to say before the crash, come into contact with the rear wall, but has a depth that enables an early transmission of forces between the front wall and the rear wall or the connected crash box.

[0013] The groove in the front wall is particularly significant in the region of the end section. It is important that the distance to the rear wall is smaller in the region of the end section. In the middle region of the crossbeam, the distance is larger. As a result, the crossbeam has a higher bending stiffness in the middle region than in the end region. The effect of the crossbeam constructed in this way is that there is no very crash-resistant connection between the crossbeam and the deformation element, but a crossbeam that allows deformation and should be able to perform rotational movement in the region of the crash box. The outermost ends of the crossbeam should be stretched in a targeted manner, while the crossbeam is compressed on the inner sides of the crash box facing each other. More energy is absorbed by the deformation during rotation and less force is introduced into the deformation element. At the same time, due to the yieldable grooves in the upper and lower walls, the material will not be overloaded. Breakage can be avoided not only in the region of the crossbeam but also in the region of the deformation element. In this way, a shorter crash box can be used again. As a result, the total weight and structural volume of the component can be reduced. These advantages are the result of early, high energy absorption. This is in turn the result of early loading of the deformation element. Without the grooves in the front wall, the crossbeam can be completely deformed before the deformation element is deformed. The advantages of the invention are therefore also due to the more strongly grooved upper and lower walls in the end sections. The more strongly grooved upper and lower walls can be understood in these regions in the sense of a specifically set set deformation which is easier to achieve in the end regions than in the middle region.

[0014] In a further improvement of the present invention, the groove in the front wall has a trapezoidal cross section in particular. The groove should have such a structure that it can realize the introduction of the force from the collision into the crash box as early as possible. The advantage of the trapezoidal cross section is that the side of the cross section, that is, the upper wall and the lower wall of the groove can be almost perpendicular to the front wall. This means that the collision force can be directly introduced into the deepest area of ​​the groove through these walls and thus introduced into the rear wall of the cross beam. The deep groove also improves the bending stiffness of the bumper assembly. Therefore, the groove preferably has a depth greater than 50% of the depth of the cross beam measured in the longitudinal direction of the motor vehicle. The groove can have a constant depth as a whole. Due to the reduction in the depth of the cross beam in the end area, the portion of the total depth occupied by the groove is correspondingly larger. It is considered particularly advantageous that the groove of the front wall has a depth in the end area that is greater than 75% of the depth of the cross beam measured in the longitudinal direction of the motor vehicle, especially 75% of the depth of the cross beam measured in the end area.

[0015] In addition, the recess should have a height measured in the height direction of the motor vehicle, which preferably extends over 25% to 50% of the height of the crossbeam. The height of the crossbeam is defined by the outer distance between the upper wall and the lower wall in the middle region. The crossbeam can additionally have flanges on the upper wall and the lower wall, for example for fastening the crossbeam to the deformation element. In the same way, a partial or continuous flange can also be provided upwards and / or downwards in the region of the front wall, which flange protrudes in height beyond the upper wall or the lower wall. In crossbeams that do not have a constant height over their entire length, the specifications regarding the height or depth of the recess are based on the arithmetic mean height in the respective end regions or in the middle region.

[0016] It is considered advantageous if the distance between the recess in the front wall and the rear wall is in the range of 5 mm to 10 mm. This allows smaller loads to be absorbed without the crash box deforming. If the load increases, the recess acts as a crash-resistant trigger in order to introduce forces into the crash box via the rear wall at an early stage.

[0017] It is considered advantageous if the front wall with the recess has a greater wall thickness than the wall of the deformation element. The force should be transmitted via the front wall. The front wall and the recess in the front wall should not deform very early, at least not before the force is introduced into the deformation element. The thickness ratio (front wall, deformation element) is preferably in the range of more than 1.5. For example, the deformation element has a wall to be deformed with a wall thickness of at most 2.4 mm, while the front wall has a wall thickness of 4 mm.

[0018] It is particularly preferred to use different materials or metal alloys, in particular different aluminum alloys, for the deformation element and the cross member. The 0.2% yield strength Rp0.2 is preferably at least 300 MPa for the cross member and at least 240 MPa for the crash box.

[0019] In addition, a trigger, for example in the form of an opening or a recess, can be provided in the crash box. The trigger assists in the controlled and uniform deformation of the crash box. In particular, the upper and lower walls of the crash box can be designed to be more flexibly flexible, since the upper and lower walls of the cross member are also softer in the end regions, in the sense of yielding more easily, due to the recesses introduced there, than in the middle region of the cross member, in which the recesses in the front wall are provided for the force transmission of the impact forces.

[0020] Between the middle region and the outer end regions there is a transition region of the crossbeam. The depth of the crossbeam changes in the transition region, since the distance between the recess and the rear wall is to be reduced. This is achieved by plastic forming. In this case, the rear wall should be more strongly curved in the transition region than the front wall, in particular. The course of the front wall is usually determined by the front or rear contour of the motor vehicle. The stronger curvature in the rear wall leads to the formation of an S-shaped bend in this region.

[0021] The crossbeam according to the invention can be produced cost-effectively by means of a cross section of the recess in the front wall which is as uniform as possible. Preferably, the distance between the rear wall and the deepest area of ​​the recess, at least in the end area, is as small as possible for reasons of crash technology and is in particular in the range of 5 mm to a maximum of 30% of the crossbeam depth measured in the middle area of ​​the crossbeam and in the longitudinal direction of the motor vehicle. From a crash technology point of view, this distance is particularly preferably between 5 mm and a maximum of 20 mm. Due to the manufacturing technology or extrusion technology, a distance of less than 10 mm is more difficult to achieve without subsequent press forming than a larger distance, so that the distance is preferably 10 mm to 20 mm. Smaller values ​​can be achieved by re-extrusion, since the end area is already stamped in the press.

[0022] The depth of the recess in the front wall is preferably at least 15 mm. The recesses in the upper and lower walls preferably have a depth of 5 to 10 mm. Recesses with a smaller depth can also extend over the entire length of the bumper assembly in the upper and lower walls, but they have a significantly smaller depth in the middle region. Preferably, the upper and lower walls are substantially straight.

[0023] The end sections have a smaller depth measured in the direction of travel than the middle region of the cross member. The end sections can be compressed, for example, by 5 to 10 mm. The upper and lower walls should have a wall thickness of no more than 4.5 to 5 mm in order to achieve sufficient bending stiffness in the middle region of the cross member. The bending stiffness in the end sections is reduced by the recesses additionally introduced there. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The invention is explained in more detail below with reference to exemplary embodiments which are shown in the drawings by way of illustration only.

[0025] In the attached figure:

[0026] Figure 1 The bumper assembly is shown in a top view;

[0027] Figure 2 An end region of the bumper assembly is shown in a top view;

[0028] Figure 3 showing an end region of a bumper assembly in perspective view;

[0029] Figure 4 A cross-sectional view showing an end region of the cross member prior to a collision;

[0030] Figure 5 A cross-sectional view showing an end region of a cross-member during a collision;

[0031] Figure 6 shows a force-displacement diagram during a collision;

[0032] Figure 7 Another collision scenario is shown in a top view, and

[0033] Figure 8 Shown in a perspective view at one end region Figure 7 collision situation. DETAILED DESCRIPTION

[0034] Figure 1 A bumper assembly 1 is shown having a cross member 2 made of an extruded hollow profile. The cross member 2 has end regions 3, 4, via which the cross member 2 is fastened to deformation elements 5, 6. The deformation elements 5, 6 (crash boxes) are provided for fastening to longitudinal beams 7, 8 of a motor vehicle, not shown in further detail. The cross member 2 is slightly curved. Its concave back side faces the center of the vehicle. Its convex front side faces away from the vehicle. A Cartesian coordinate system shows the X, Y and Z directions to which reference is made below. The X direction points in the longitudinal direction of the vehicle, not shown in detail. The depth T1 of the cross member 2 is measured in the X direction. The height H1 ( Figure 4 ) is measured in the Z direction. The longitudinal direction of the crossbeam 2 refers to the direction along the longitudinal axis of the crossbeam 2. This basically refers to the direction in the Y direction. In this sense, the front wall 9 and the rear wall 10 are in the longitudinal direction of the crossbeam 2, as well as the upper wall 11 and the lower wall 12 ( Figure 3 ) extend parallel to each other.

[0035] from Figure 1 It can be seen in the illustration that the cross member 2 has a middle region 13. In this region 13, the cross section of the cross member 2 is constant. A transition region 14, 15 respectively adjoins the middle region 13 in the direction of the two ends. The transition regions 14, 15 are followed by the end regions 3, 4. The cross member 2 is designed to be essentially mirror-symmetrical with respect to its middle transverse plane MQE. The difference lies essentially in the fact that a through-opening for the traction device is provided in the right end region 4. In this sense, the damping elements 5, 6 are also essentially symmetrical. The adaptation is only achieved by the necessity of connecting the traction device to the longitudinal member 8, upstream of which the deformation element 6 is located.

[0036] Figure 2One of the end regions 3 of the cross member 2 is shown in an enlarged view. The end region 3 is wider than the transition region 14. However, the depth T2 of the cross member 2 measured in the X direction is smaller than the depth T1 in the middle region. The depth T1 decreases in the transition region 14. In the transition region 14, the course of the front wall 9 is slightly more strongly curved, wherein the course of the front wall 9 in the region of the deformation element 5 runs essentially straight. The rear wall 10 runs parallel to the front wall 9 in the middle region 13 and in the end region 3. Deviations from this exist only in the transition region 14. In this region, the rear wall 10 is curved in an S-shaped manner and approaches the front wall 9 slightly from the middle region 13 to the end region 3. This course is produced by plastic deformation of the end region 3 and the transition region 14.

[0037] The deformation element 5 has a flange plate 18 for fastening to a motor vehicle. Instead of a flange plate, the deformation element can also be designed to be inserted into a longitudinal beam of a motor vehicle and to be screwed to the longitudinal beam. The front side 19 of the deformation element 5 does not extend parallel to the flange plate 18, but is matched to the course of the rear wall 10 of the cross member 2. The front side 19 of the deformation element 5 and the rear wall 10 of the cross member 2 are fixedly connected to each other.

[0038] Figure 3 The cross section of the cross member 2 is shown in a perspective view. The cross member 2 has a recess 20 in its front wall 9. The recess extends over the entire length of the cross member 2. The recess is an open recess, since it also extends through the end regions 3, 4 and is open toward the outermost end of the cross member 2. The recess 20 has a trapezoidal cross section with a deepest region 21. The deepest region 21 extends parallel to the rear wall 10. The deepest region 21 of the recess 20 is closer to the rear wall 8 than to the front wall 9.

[0039] from Figure 3 As can be seen from the diagram of FIG. , the horizontal distance D1 ( Figure 4 ) is relatively small. This distance in the region of the end region 3 is in the order of magnitude of between 5 mm and 10 mm. Correspondingly, the groove 20 is relatively deep. The groove depth T3 of the groove 20 is greater than 50% of the depth T1 of the cross member 2 measured in the longitudinal direction of the motor vehicle, i.e. in the X direction. Figure 4 The section plane is located in the end region 3 of the cross member 2 .

[0040] The height H2 of the groove 20 is also relatively large in relation to the height H1 of the crossbar 2 measured from the outside between the upper wall 11 and the lower wall 12. The height H2 increases from the deepest region 21 towards the inlet of the groove 20, i.e. towards the front wall 9, since the upper groove wall 22 and the lower groove wall 23 are slightly inclined. Furthermore, the upper groove wall 22 and the lower groove wall 23 extend in a straight line. Thus, the height H2 in the region of the front wall 9 extends over 25% to 50% of the height H1 of the crossbar 2.

[0041] The large groove depth T3 of the groove 20 ensures that the deepest region 21 comes into contact with the rear wall 10 at an early stage in the event of an impact with the front wall 9 . Figure 5 The early moment of such a collision is shown. Here, the groove 20 or the deepest region 21 with the upper and lower groove walls 22, 23 is to behave relatively rigidly, while the upper wall 11 and the lower wall 12 are to be yielding. For this reason, a further groove 24 is provided in the upper wall 11. A corresponding groove 25 is also provided in the lower wall 12. Figure 3 It is shown that the grooves 24, 25 are open toward the free end of the cross member 2. The grooves 24, 25 are located in the end regions 3, 4 and begin in the transition regions 14, 15. The grooves 24, 25 are produced by deforming the end regions 3, 4, while the rear wall 10 is moved in the direction of the front wall 9. In this case, the grooves 24, 25 point inwards, that is, toward the deep groove 20 in the front wall 9. Figure 3 It is clear from the illustration that there is also a groove 24a in the middle region 13 of the upper wall 11. However, this groove 24a is very flat, so that the upper wall 11 and the lower wall 12 of the same design can be considered to be essentially straight or extended. As a result, the groove of the upper wall 11 and the resulting curvature as well as the groove of the lower wall 12 are larger in the end regions 3, 4 due to the deeper grooves 24, 25 than in the middle region 13.

[0042] Figure 5 The time shortly after the deepest area 21 of the groove 20 contacts the rear wall 10 is shown according to Figure 4 . The rear wall 10 is to be deformed in a targeted manner so as to continue the deformation in the deformation element (not shown in detail here). The recess 20 thus serves as a trigger for the deformation element so that the deformation of the deformation element has already begun before the deformation of the end regions 3, 4 of the cross member 2 has ended. It can be seen from this illustration that the recesses 24, 25 are deformed differently here than the deep recess 20 in the front wall 9.

[0043] Figure 6A force-displacement diagram is shown, in which the forces occurring during deformation during a collision are plotted in relation to the penetration depth. A sectional view of the left bumper attachment is also shown. The same reference numerals as in the above-described exemplary embodiment are used. At an early moment in the collision, the test body 26 initially deforms only the end region of the cross member 2, wherein the recess 20 with its deep region 21 impacts the rear wall 10. The rear wall 10 is deformed in its middle height region, thereby introducing a deformation of the deformation element. The course of the curve shows that a relatively constant force profile occurs until the maximum penetration depth is reached. A simulation is shown on the right in the plane of the figure: when the maximum penetration depth is reached, the recess 20 penetrates relatively far into the deformation element 6. The deformation element 6 is deformed in such a way that the cross member 2 with its end region in the middle height region of the deformation element 6 penetrates deeper into the deformation element 6 than in the upper and lower height regions of the deformation element 6. This penetration makes it possible for the deformation element 6 to dissipate the collision energy by deformation in advance, while the end regions of the cross member 2 are not yet completely deformed.

[0044] Figure 6 shows a collision at low speed, while Figure 7 and Figure 8 Another load case is shown. The test body 27 acts in the middle area of ​​the motor vehicle. The collision speed is high. As a result, two deformation areas of the cross member 2 are formed in the area of ​​the crash box. In the area 28 marked with "compression", compression of the cross member 2 occurs due to the grooves 24, 25 in the upper wall 11 and the lower wall 12. The grooves 24, 25 in the area 28 prevent cracks in the cross member 2. The material behaves in a yielding manner there. At the same time, a tensile force is applied to the outermost end area 29 of the cross member 2 due to the torque M1. This area is marked with "tension". The tensile force causes this area to expand.

[0045] from Figure 8 , it can be seen in the perspective view that the recesses 24, 25 in the upper wall 11 and the lower wall 12 expand due to the collision. The recesses 24, 25 act as expansion joints to a certain extent to prevent the cross member 2 from being torn off the deformation element 6 at particularly high torques M1. If the cross member 2 is torn off the deformation element 6 in the region 29, the deformation energy cannot be absorbed in the end region 3. This would only result in a rotation around the region 28. The recesses 24, 25 in the upper and lower walls 11, 12 therefore have a dual function depending on the collision situation.

[0046] Reference numerals

[0047] 1 Bumper assembly

[0048] 2 Beam

[0049] 3 2 end area

[0050] 4 2 end area

[0051] 5 Deformation elements

[0052] 6 Deformation elements

[0053] 7 Stringer

[0054] 8 Stringer

[0055] 9 2 front wall

[0056] 10 2 back wall

[0057] 11 2 upper wall

[0058] 12 2 lower wall

[0059] 13 2 middle area

[0060] 14 13 Transition Area

[0061] 15 13 Transition Zone

[0062] 18 5 flange

[0063] 19 5 front side

[0064] 20 grooves

[0065] 21 20's deepest area

[0066] 22 Upper groove wall

[0067] 23 Lower groove wall

[0068] 24 3 in 11 grooves

[0069] 24a 13 out of 11 grooves

[0070] 25 12 in the groove

[0071] 26 test subjects

[0072] 27 Test subjects

[0073] 28 2 Area

[0074] 29 2 Area

[0075] D1 Distance between 21 and 10

[0076] H1 2 Height

[0077] H2 20 Height

[0078] MQE mid-transverse plane

[0079] T1 13 in 2 depth

[0080] T2 16 in 2 depth

[0081] T3 20 groove depth

[0082] X Longitudinal direction of the vehicle

[0083] Y The lateral direction of the vehicle

[0084] Z The height of the vehicle

Claims

1. A bumper assembly (1) comprising a cross member (2) and two deformation elements (5, 6) for being arranged between end regions (3, 4) of the cross member (2) and longitudinal members (7, 8) of a motor vehicle, wherein: The crossbeam (2) is embodied as a hollow profile having a front wall (9), a rear wall (10), an upper wall (11) and a lower wall (12), the hollow profile being a single-chamber profile, the front wall (9) having a groove (20) extending in the longitudinal direction of the crossbeam (2) and extending over the entire length of the crossbeam (2), the groove (20) having a deepest area (21) extending at a distance (D1) from the rear wall (10), the upper and lower walls (11, 12) each having at least one further groove (24, 25) in the end areas (3, 4), the further groove extending in the longitudinal direction of the crossbeam (2), so that the upper wall (11) and the lower wall (12) are 12) The grooves are more strongly grooved in the end regions (3, 4) than in the middle region of the cross member (2), so that the distance between the front wall (9) and the rear wall (10) is smaller in the end regions (3, 4) than in the middle region (13) of the cross member (2), the distance (D1) between the groove (20) of the front wall (9) and the rear wall (10) is between 5 mm and a maximum of 30% of the depth (T1) of the cross member (2) in the middle region (13) measured in the longitudinal direction of the vehicle and including 5 mm at least in the end regions (3, 4), the groove (20) in the front wall (9) having a groove depth (T3) which is greater than 50% of the depth (T1) of the cross member (2) measured in the longitudinal direction of the vehicle.

2. The bumper assembly (1) according to claim 1, characterized in that: The cross member (2) is an extruded profile, wherein the further grooves (24, 25) are produced in the end regions (3, 4) by forming.

3. The bumper assembly (1) according to claim 1 or 2, characterized in that: The distance (D1) of the recess (20) in the front wall (9) from the rear wall (10) is smaller in the region of the end regions (3, 4) than in the middle region (13) of the cross member (2).

4. The bumper assembly (1) according to claim 1 or 2, characterized in that: The groove (20) in the front wall (9) has a trapezoidal cross section.

5. The bumper assembly (1) according to claim 1 or 2, characterized in that: The groove (20) of the front wall (9) has a groove depth (T3) in the region of the end regions (3, 4) which is greater than 75% of the depth (T1) of the cross member (2) measured in the longitudinal direction of the vehicle.

6. The bumper assembly (1) according to claim 1 or 2, characterized in that: The recess (20) of the front wall (9) has a height (H2) measured in the height direction of the motor vehicle, which extends over 25% to 50% of the height (H1) of the cross member (2).

7. The bumper assembly (1) according to claim 1 or 2, characterized in that: The distance (D1) between the recess (20) of the front wall (9) and the rear wall (10) is 5 mm to 20 mm at least in the end regions (3, 4).

8. The bumper assembly (1) according to claim 1 or 2, characterized in that: The distance (D1) between the recess (20) of the front wall (9) and the rear wall (10) is 10 mm to 20 mm at least in the end regions (3, 4).

9. The bumper assembly (1) according to claim 1 or 2, characterized in that: The front wall (9) having the recess (20) has a greater wall thickness than the walls of the deformation elements (5, 6).

10. The bumper assembly (1) according to claim 1 or 2, characterized in that: Transition regions (14, 15) to a middle region (13) of the cross member (2) are provided at the end regions (3, 4), in which the depth (T1, T2) of the cross member (2) measured in the longitudinal direction of the vehicle changes, wherein in the transition regions (14, 15) the rear wall (10) is more strongly curved than the front wall (9).

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