Bumper beam for motor vehicles and method for manufacturing bumper beam.

Abstract

A bumper beam for a motor vehicle is produced from an extruded hollow profile and has a front side forming an impact side, a rear side opposite the front side, end regions configured for connection to the motor vehicle, a central region extending between the end regions and bent toward the impact side, and a top side and a bottom side connecting the rear side to the front side. Each of the top side and the bottom side has a protruding flange, which is separated from the rear side by a separating cut, which is configured to end before the end region so that the flange is connected to the bumper beam in the end region.

Description

Technical Field

[0001] The invention relates to a bumper beam for a motor vehicle and to a method for producing a bumper beam. Background Art

[0002] It would be desirable and advantageous to provide an improved bumper beam for a motor vehicle and an improved method for producing a bumper beam and to obviate the disadvantages of the other prior art. Summary of the invention

[0003] According to one aspect of the present invention, a bumper beam for a motor vehicle is produced from an extruded hollow profile and includes a front side forming an impact side, a rear side opposite to the front side, an end area configured to be connected to the motor vehicle, a central area extending between the end areas and bent toward the impact side, and a top side and a bottom side connecting the rear side and the front side and each having a protruding flange, the protruding flange being separated from the rear side by a separation cut, the separation cut being configured to terminate before the end area so that the flange is connected to the bumper beam in the end area.

[0004] When used in the description, the term "side" relates to the position of the side relative to the cross section of the bumper beam. A side may have a gradient, a chamfer, a depression or a rounded corner and does not necessarily relate to a straight wall. With regard to the "hollow profile", hollow profiles with a rectangular base configuration are currently preferably used.

[0005] According to the invention, the extruded hollow part is cut to the required length and forms the starting structure for producing a bumper crossbeam. The flanges of the extruded hollow profile advantageously point in opposite directions, i.e. upward and downward. The end region can have an outer end, which is dimensioned to protrude beyond the connection region to the motor vehicle. The bumper crossbeam is bent toward the impact side, while the end region is bent away from the impact side. Thus, viewed from the middle of the motor vehicle, the bumper cross section has a generally concave profile corresponding to the contour and other parameters of the motor vehicle.

[0006] According to the invention, the flange is separated from the rear wall in the central region of the bumper beam by a separating cut. The separating cut does not extend over the entire length of the bumper beam and ends before the end region. The bumper beam with the separating cut comprises a one-piece structure with all walls and the flange, which are produced by an original and conventional extrusion process and are therefore connected to one another in one component made of the same material.

[0007] The bumper cross member according to the invention offers greater freedom of construction, since the region of the flange, as separated from the rear wall, can have a different contour in the end product than the rear wall of the bumper cross member. Advantageously, due to the separation cut and the subsequent forming operation, the separation region of the flange is at an increased distance from the rear wall. In combination with the arched curvature of the bumper cross member towards the impact side, an arch with two parallel chords is created, wherein the two chords are formed by the separation region of the flange. As a result, the flange advantageously extends straight and transversely to the longitudinal axis of the vehicle in the central region, while the bumper cross member is curved in the region of the hollow profile.

[0008] The rear portion of the beam formed by the chord-shaped flange is able to absorb stresses which push the end of the front portion of the beam apart in the event of an impact. The flange responds to tensile stresses while the front or impact side of the bumper beam responds to compressive forces. Due to the increased distance of the flange from the rear side, the section modulus against bending increases without increasing the total weight of the extruded hollow profile. The present invention therefore provides a teaching that enables the production of a bumper beam from a single hollow profile, wherein the bumper beam has a front first beam and a rear second beam, without the two beams needing to be connected to each other by an additional manufacturing step. Thus, an integral production is possible in a cost-effective manner. Thus, the bumper beam according to the invention comprises a central area in which one of the two beams is behind the other.

[0009] According to another advantageous feature of the invention, the flange can have a front surface and a rear surface, wherein the front surface or rear surface of the flange faces each other in the central region. Advantageously, the rear surface and the front surface extend in a parallel relationship, wherein the flanges are bent around their own longitudinal axis in the central region so that the front surface or rear surface of one flange faces the front surface or rear surface of the other flange. In this context, the term "facing each other" should be understood as meaning that the front surface or the rear surface both define an angle of less than 90°, in particular an angle of less than 45°. An angle of less than 20° is currently preferred. These surfaces point upward and downward, respectively, while the surface normals of the corresponding other surfaces intersect. The angling or twisting of the flange reduces the structural height of the bumper beam in the central region without adversely affecting the reinforcement characteristics of the flange. Due to the partial separation of the flange, in particular due to the angling, additional air inlet options are formed for the radiator of the motor vehicle.

[0010] The partial twisting and twisting of the flange also achieves a shortening of the flange. This shortening at least partially compensates for the shortening of the bumper beam caused by the bending of the hollow profile towards the impact side. In addition, the profile of the flange can include a longitudinally extending bend to further shorten the overall length.

[0011] According to another advantageous feature of the invention, the front or rear surface of the flange can define an angle in the range of ±60°, advantageously in the range of ±40°, in the central region. An angle in the range of ±20° is currently preferred. References to positive and negative signs should be understood here to mean that the flange has a separating cut edge pointing towards the hollow profile or away from the hollow profile.

[0012] Of course, within the scope of the invention, it is also conceivable to avoid twisting the flange or the front and rear surfaces. In this case, the flange or the front and rear surfaces extend substantially vertically corresponding to the mounting position of the bumper crossbeam.

[0013] The central region of the hollow profile may be stretched, ie its length may be increased, so that the flange is under tensile stress and acts as a tie rod that responds to the tensile stress.

[0014] Without increasing the structural volume or weight of the flange at the rear end of the hollow profile, a connection can be provided which is produced when the hollow profile is extruded. Unlike multi-component structures, no welding operations are required when producing the flange. As a result, the production of the bumper beam according to the invention becomes significantly more cost-effective and faster and more efficient to manufacture.

[0015] According to another advantageous feature of the invention, the front or rear surface of the flange can extend substantially parallel to the top and bottom sides of the crossbeam in the central region, i.e. substantially horizontally. Advantageously, the front or rear surface of the flange is twisted by 90°. When the separating cutting and twisting operations are carried out in one stroke, it is possible to provide an angle deviating from 90° due to the springback of the material.

[0016] Advantageously, the twisting operation is performed at least partially in time sequence before the separating cut is performed. For this purpose, a single-step forming and cutting tool can be used. The tool is configured so that the forming member first contacts the flanges to twist them, and then the cutting member performs the separating cut with the cutting edge in the same stroke, while the hollow profile is supported in the region of the rear wall.

[0017] The flange twisted apart in the central region results in a height of the bumper cross member in the central region being smaller than a height of the bumper cross member in the end regions. The flange assumes the task of connecting the bumper cross member to the motor vehicle in the end regions. According to a further advantageous feature of the invention, the rear surface and the rear side of the flange can thus have the same orientation in the end regions, i.e. be oriented substantially in the vertical direction of the motor vehicle.

[0018] According to another advantageous feature of the invention, a transition zone can be arranged between the central zone and the end zone. The orientation of the front and rear surfaces of the flange changes in the transition zone. The front and rear surfaces of the flange can have an orientation in the transition zone that is progressively twisted by 60°-90°, advantageously by 70°-90°, in the transition zone. It is currently preferred to twist the front and rear surfaces of the flange by 80°-90° in the transition zone. As a result, the front and rear surfaces of the flange face each other. A progressive transition should be understood as being related to a change in the direction of the flange that is not abrupt, i.e. the change in direction is not effected over a very short length portion. In this way, the presence of material stresses that cause deformations is eliminated.

[0019] According to another advantageous feature of the invention, the transition regions each have a certain length and the flanges each have a certain height, wherein the length of the transition regions corresponds to at least twice the height of the flanges. A minimum length of the transition regions is currently preferred, which is two to four times the height of the flanges. In this way, a smooth transition is achieved in the shape of a spiral curvature.

[0020] The flange may be at an angle of 60°-90°, advantageously 70°-90°. It is currently preferred that the flange is at an angle of 80°-90°. The angling of the flange is at least partially achieved, advantageously substantially achieved, while the flange is still connected to the hollow profile. After undergoing the separating cut, any further forming operations of the structural component can be carried out independently of each other.

[0021] According to another advantageous feature of the invention, the separating cut can extend up to the transition region. Due to the provision of a relatively long separating cut, the flange can be more easily handled and bent. In addition, regardless of the profile of the flange, the long separating cut makes the forming operation of the hollow profile simpler.

[0022] The hollow profile absorbs the main stresses of the bumper beam in the event of an impact. The flange provides support for the hollow profile and can be moved in a targeted manner relative to the hollow profile into a desired position, taking into account the long separation cut.

[0023] According to another advantageous feature of the invention, the flange can be configured with a curvature in the direction towards the impact side, which curvature is smaller than the curvature of the hollow profile towards the impact side. In addition, the curvature of the flange can advantageously be provided only in a short length portion, so that the main length portion of the flange extends straight like a chord. Thus, when viewed from the impact side, the flange is at a distance from the rear side in the central region. This distance decreases progressively towards the end region.

[0024] According to another advantageous feature of the invention, said distance may be in the range 5 mm to 200 mm.

[0025] The curvature of the flange or the course of the curvature in the direction of impact deviates from the course of the curvature of the hollow profile, in particular in the transition region. Advantageously, the central region is configured such that the hollow profile and the flange extend substantially in a parallel relationship over a certain length portion. The bumper crossbeam that is curved in the direction of impact advantageously has a region with a greater curvature in the transition region, in which the flange is also curved. The transition region of the crossbeam or hollow profile is advantageously larger or longer than the transition region of the flange.

[0026] According to another advantageous feature of the invention, the flange can have a separation cut edge and a free edge opposite to the separation cut edge. A currently preferred configuration is that the free edge faces away from the rear side of the crossbeam in the central area. As an alternative, it is also conceivable to first separate the flanges in at least one area and then twist the flanges around the longitudinal axis after separation so that their free edges point in the direction of the impact side and the separation cut edge is bent backwards. However, for manufacturing reasons, it may be more advantageous to twist the flanges backwards so that the free edge points to the motor vehicle and the separation cut edge points in the direction of the front side of the bumper crossbeam. Of course, within the scope of the invention, the flanges can also be twisted differently so that the rear surface of one flange finally points to the front surface of the other flange.

[0027] According to another advantageous feature of the invention, the hollow profile can be implemented as a circumferentially closed hollow profile with at least one chamber. The hollow profile can also have a separating wall in its interior in order to realize a multi-chamber profile. Such a reinforcement of the hollow profile can be easily realized in a cost-effective manner by an extrusion process. The internal structure of the hollow profile can be constructed completely independently of the construction of the flange.

[0028] The flange itself does not constitute a hollow profile. Advantageously, the flange comprises a substantially flat web of uniform height determined by the extrusion process. By compressing at least one region of the hollow profile, the height or depth of the hollow profile can be varied in the longitudinal direction. The hollow profile can advantageously undergo a material removal process after production in order to produce a cutting region, for example to provide an opening for a traction device or to connect the hollow profile to a crash box.

[0029] According to another aspect of the present invention, a method for producing a bumper beam comprises: forming an extruded hollow profile having a hollow chamber and an upper side and a lower side, each of the upper side and the lower side having a flange pointing in opposite directions; partially separating the flange by moving a stamping tool in a direction from the front side to the rear side of the hollow profile and separating the flange in a central area of ​​the hollow profile; and bending the central area of ​​the hollow profile in the direction of the front side so as to increase the distance of the flange from the rear side in the central area.

[0030] According to the invention, the flange remains connected to the hollow profile in the end region of the hollow profile.

[0031] According to another advantageous feature of the invention, the flange can be formed in the central region so that the front surface or the rear surface of the flange faces each other in the central region. Advantageously, the flange is bent 60°-90°. The optional forming operation can be implemented at least partially before the cutting operation, advantageously within the above-mentioned angular range of 60°-90°. The forming operation can also be continued after the separation has been performed. The separation operation can also represent an intermediate step during the optional forming operation. Advantageously, the optional forming operation and the separation operation can be performed in a single stroke by the same punching tool. To this end, the punching tool is moved through the top side and the bottom side of the flange. The punching tool is manipulated so that it moves from the front side in the direction of the flange, wherein the flange is twisted backward in the stroke direction. When the desired twisting has been implemented, the punching tool is moved further until the cutting edge of the punching tool acts on the flange to separate the flange from the top side and the bottom side of the hollow profile. During the entire process, the end region of the hollow profile (including the flange) is fixed in place so that the flange cannot be deformed in this region. Formed between the formed central region of the flange and the fixed end region is a transition region in which the flange is twisted helically by approximately 60° to 90°. In this variant of the process, the front surface of the flange points outwards after undergoing the forming operation. If it is desired to provide a front surface that should point inwards, the forming operation is performed in the opposite direction so that the separating cut edge of the flange faces away from the rear side of the hollow profile.

[0032] In a subsequent manufacturing step, the hollow profile is bent by moving the end portion relative to the central region in the direction of impact. At the same time, the end position of the flange relative to the rear side is adjusted so that the free edge does not protrude beyond the end region at the rear, but extends in the central region at a distance from the end region. The maximum distance may be 5 mm to 200 mm, advantageously 30 mm to 150 mm.

[0033] According to another advantageous feature of the invention, the hollow profile can be stretched over its length in order to tension the exposed area of ​​the flange. The end can finally be trimmed and provided with an opening for attachment to a motor vehicle. The bumper beam can further undergo a calibration step to assume its desired shape. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Other features and advantages of the present invention will become more apparent by reading the following description of currently preferred exemplary embodiments of the invention with reference to the accompanying drawings, in which:

[0035] Figure 1A perspective view of an embodiment of a hollow profile for producing a bumper beam according to the present invention;

[0036] Figure 2 A three-dimensional diagram of the hollow profile when its flange is formed;

[0037] Figure 3 A three-dimensional view of the hollow profile when its flange continues to be formed and undergoes separation cutting;

[0038] Figure 4 is a perspective view of the hollow profile, wherein the partially separated flange is depicted in a further formed state;

[0039] Figure 5 is a perspective view of the hollow profile, wherein the partially separated flange is depicted in a further formed state;

[0040] Figure 6 is a perspective view of a hollow profile undergoing a bending operation;

[0041] Figure 7 is a perspective view of a hollow profile after undergoing a bending operation;

[0042] Figure 8 is a cross-sectional perspective view of the hollow profile before trimming its ends;

[0043] Fig. 9 is a top view of the finished bumper beam after the ends have been trimmed;

[0044] Fig.10 for Figure 1 A cross-section of the hollow profile before undergoing a forming operation;

[0045] Fig.11 A cross section of another embodiment of a hollow profile for producing a bumper beam according to the present invention;

[0046] Fig.12 is a top view of a finished bumper beam having different formed flanges;

[0047] Fig.13a is a cross-section of a central region of a bumper beam having a facing rear surface;

[0048] Fig.13b is a cross-section of a central region of a bumper beam having a facing front surface;

[0049] Fig.14 A top view of a bumper beam according to the present invention;

[0050] Fig.14a for Fig.14The bumper beam along Fig.14 A cross section taken along section line II in FIG. 1 ; and

[0051] Fig.14b for Fig.14 The bumper beam along Fig.14 The cross section is taken along the section line II-II. DETAILED DESCRIPTION

[0052] In all drawings, identical or corresponding elements may generally be represented by the same reference numerals. The embodiments described should be understood as illustrative of the present invention without limiting in any way. It should also be understood that the drawings are not necessarily to scale, and that the embodiments may be illustrated by graphical symbols, imaginary lines, diagrammatic representations, and partial views. In some cases, details that are not necessary for understanding the present invention or that make other details difficult to understand may have been omitted.

[0053] Turning now to the drawings, in particular Figure 1 , shows a perspective view of an embodiment of a hollow profile for producing a bumper beam according to the invention, which is generally indicated by reference numeral 1. The hollow profile 1 as a semi-finished product has two chambers and is made of an aluminum alloy. The hollow profile 1 is produced by extrusion and cut to the desired size.

[0054] The hollow profile 1 and the bumper cross member produced from the hollow profile 1 have a front side 2, which is Figure 1 , is at the top in the drawing plane of the vehicle and represents the impact side. With respect to the motor vehicle coordinate system, the x-axis points upwards, the y-axis points to the right in the drawing plane and the z-axis points to the left in the drawing plane. The hollow profile 1 has a rear side 3, which is therefore at the bottom in the drawing plane. The observer sees the bottom side 5, while the top side 4 faces away from the rear side 3. The upper flange 6 and the lower flange 7 are located in the plane of the rear side 3 and extend perpendicularly to the top side 4 and the bottom side 5 beyond them. The flanges 6, 7 are each straight and arranged oppositely.

[0055] To produce a bumper cross member from the hollow profile 1, the flanges 6, 7 are formed in the central region 11. In a manner not shown in greater detail, the forming tool is moved in the impact direction indicated by the arrow A over the top side 4 and the bottom side 5 in order to form the flanges 6, 7 downwards and rearwards, as shown in FIG. Figure 2 As shown in FIG. , the flanges 6, 7 are fixed in place in the end regions 8, 9 during the forming operation. For simplicity, Figure 2 Only the forming operations related to the lower flange 7 are depicted. A person skilled in the art will appreciate that the upper flange 6 undergoes the same forming operations.

[0056] Figure 3 A further method step during the forming operation is shown, in which a separating cut 10 is performed to partially separate the flanges 6, 7 from the hollow profile 1. The separating cut 10 extends in the longitudinal direction (y direction) and is adjacent to the top side 4 and the bottom side 5. At the same time, the flanges 6, 7 undergo further forming operations in the central region 11, such as Figure 4 . During this continuous forming operation, the flange 7, which has already been separated in the central region 11, is bent by almost 90°. Adjoining the central region 11 at the opposite ends are transition regions 12, 13, in which the flanges 6, 7 assume a spiral shape at an angle of almost 90°. The separating cut edge 14 of the flange 7 points upward in the drawing plane, that is, toward the front side 2, while the free edge 15 of the flange 7 faces away from the front side 2.

[0057] Figure 5 The flange 7 is shown after having undergone the above-described forming operation and before the hollow profile 1 is shaped. Figure 6 The hollow profile 1 is shown undergoing a bending operation, wherein the hollow profile 1 is bent in an arched manner toward the impact side, i.e. upwards in the drawing plane. As a result, the distance between the flanges 6, 7 and the rear side 3 of the hollow profile 1 increases in the central region 11, i.e. where the separating cut 10 has been formed. Figure 7 The final state is shown after undergoing a bending operation and before trimming the ends after the bending operation. The end regions 8 , 9 constitute the last regions of the hollow profile 1 , so that the central regions 11 of the flanges 6 , 7 do not protrude rearwards beyond the end regions 8 , 9 .

[0058] Figure 8 1 is a perspective view of a cross section of a shaped hollow profile or bumper beam 1. It is obvious that the flanges 6, 7 have a position in the central area 11 in which their rear surfaces 16, 17 face each other. The rear surfaces 16, 17 are at an angle of more than 80°, even if not exactly 90°. The two flanges 6, 7 thus effectively extend in a parallel relationship. The flanges 6, 7 are bent helically in the transition area 13 and extend again approximately parallel to the rear side 3 in the end area 9. In this area, the flanges 6, 7 can be attached to a crash box, which is not shown in more detail here. Figure 8 The end regions 8, 9 shown in still have to undergo trimming operations. The bumper beam 1 thus produced can then be calibrated and undergo material removal operations, such as punching, cutting operations, to connect the structure to a motor vehicle. The maximum distance D1 of the flanges 6, 7 to the rear side 3 is 5 mm-200 mm.

[0059] Fig. 9The top view of FIG. 1 shows the final profile of the finished bumper beam 1. A particular advantage of the bumper beam 1 according to the invention is that the flanges 6, 7 with the facing rear surfaces 16, 17 or the facing front surfaces 18, 19 have a different function in the central region 11 than in the end regions 8, 9. The flanges 6, 7 point upward and downward in the end regions 8, 9 and have the function of allowing the bumper beam 1 to be mounted to the motor vehicle, while the flanges 6, 7 are separated from the hollow profile 1 in the central region 11 and have the function of a second beam behind the first beam or the function of a chord of an arc. The flanges 6, 7 act as brackets between the end regions 8, 9 and increase the section modulus of the entire bumper beam 1 against deformation caused by impacts. In addition, the flanges 6, 7 can be produced in a single manufacturing step using a simple forming operation, without the need for a joining operation and without increasing the overall weight of the extruded hollow profile or the finished bumper beam 1.

[0060] The flanges 6 and 7 have the same height H1 ( Figure 8 ). The distortion of the flanges 6, 7 in the transition regions 12, 13 does not cause adverse microstructural changes and can even influence the strain hardening in these regions. Figure 8 As shown in FIG, the transition regions 12, 13 have a length L1 which corresponds to approximately two or three times the height H1 of the lower flange 7. The upper flange 6 can have a height which differs from the height H1 of the lower flange 7.

[0061] In a manner not shown in greater detail, the separating cut 10 extends as far as the transition areas 12, 13. Fig. 9 It is obvious that the transition regions 12, 13 of the flanges 6, 7 are shorter than the transition regions 20, 21 of the hollow profile 1. Accordingly, the central region 11 relative to the flanges 6, 7 is larger than the central region 22 of the hollow profile 1. In the region where the central regions 11, 22 overlap, the flanges 6, 7 extend in a parallel relationship relative to the hollow profile 1. Since the hollow profile 1 is more curved than the flanges 6, 7, the transition regions 20, 21 of the hollow profile 1 are wider. As a result, the free edge 15 opposite the separating cut edge 14 faces away from the rear side 3 of the hollow profile (or the finished bumper beam) in the respective central region 11, 22, but is also spaced apart from the rear side 3 at a significantly greater distance in the central region 22 of the hollow profile 1 than in the transition regions 12, 13 of the flanges 6, 7.

[0062] Fig.10 shows a cross section of a hollow profile 1, and Fig.11A cross section of another embodiment of a hollow profile for producing a bumper beam according to the invention is shown, which is generally designated by reference numeral 100. It is apparent that the hollow profile 1, 100 comprises a multi-chamber design with different corner configurations. For example, the hollow profile 1, 100 has two chambers. The flanges 6, 7 lie in one plane with the rear side 3 and extend perpendicularly from the top side 4 and the bottom side 5, respectively.

[0063] Fig.12 A top view of a variant of the finished bumper beam 1 is shown. Fig. 9 The corresponding parts in the embodiment are indicated by the same reference numerals and are not explained again. The following description will focus on the differences between the embodiments. In this embodiment, the flanges 6, 7 are oriented so that in the central area 11, their front surfaces 18, 19 point to each other and their rear surfaces 16, 17 point outwards.

[0064] Fig.13a and 13b Two configurations of the bumper beam 1 are shown in cross section. When the front surfaces 18, 19 face each other, the flanges 6, 7 define an angle W which is positive +W, and when the rear surfaces 16, 17 face each other, the flanges 6, 7 define an angle W which is negative -W. The angle W is greater than 60°.

[0065] Fig.14 FIG. 1 is a top view of a bumper beam 1 according to the invention, wherein the flanges 6, 7 have not yet been twisted about their longitudinal axis. Fig.14a ( Fig.14a For along Fig.14 As can be seen from the section taken along the section line II in FIG. 1 , the flanges 6 , 7 have the same orientation in the central region 11 as in the end regions 8 , 9 . Fig.14b ( Fig.14b For along Fig.14 ) illustrates the maximum distance D1 between the flanges 6, 7 and the rear side 3 in the central region 11. The hollow profile 1 is curved and can be stretched by a suitable forming operation so that the flanges 6, 7 are stretched in the central region 11.

[0066] Although the present invention has been illustrated and described in conjunction with the presently preferred embodiments shown and described in detail, the invention is not limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit and scope of the invention. The embodiments are chosen and described in order to explain the principles of the invention and the practical application, thereby enabling those skilled in the art to best utilize the invention and various embodiments with various modifications suitable for the particular use contemplated.

[0067] What is claimed as new and desired to be protected by Letters Patent is set forth in the following claims and includes equivalents to the elements recited therein.

Claims

1. A bumper beam for a motor vehicle, the bumper beam being produced from an extruded hollow profile and comprising: forming the front side of the impact side; a rear side opposite to the front side; an end region configured for attachment to the motor vehicle; a central region extending between the end regions and curving toward the impact side; as well as A top side and a bottom side, the top side and the bottom side connecting the rear side and the front side and each having a protruding flange, the protruding flange being separated from the rear side by a separation cut, the separation cut being configured to terminate before the end region so that the flange is connected to the bumper beam in the end region.

2. The bumper beam according to claim 1, characterized in that: The flanges each have a front surface and a rear surface, wherein the front surfaces or the rear surfaces of the flanges face each other in the central region.

3. The bumper beam according to claim 2, characterized in that: The front or rear surface of the flange defines an angle of at most 60° in the central region.

4. The bumper beam according to claim 2, characterized in that: The rear surface of the flange and the rear side have the same orientation in the end region. 5 . The bumper beam of claim 2 , further comprising a transition region between the central region and the end regions, wherein the front and rear surfaces of the flange have an orientation that twists in a progressive manner in the transition region.

6. The bumper beam according to claim 5, characterized in that: The transition regions each have a certain length and the flanges each have a certain height, wherein the length of the transition regions corresponds to at least twice the height of the flanges.

7. The bumper beam according to claim 5, characterized in that: The separating cut extends as far as the transition region.

8. The bumper beam according to claim 1, characterized in that: The flange is configured with a curvature in the direction toward the impact side which is smaller than the curvature of the hollow profile toward the impact side, so that the flange is spaced apart from the rear side in the center region when viewed from the impact side.

9. The bumper beam according to claim 8, characterized in that: The distance is in the range of 5 mm to 200 mm.

10. The bumper beam according to claim 1, characterized in that: The flange has a separation cutout edge and a free edge opposite the separation cutout edge, wherein the free edge faces away from the rear side in the central region.

11. The bumper beam according to claim 1, characterized in that: The hollow profile is embodied as a circumferentially closed hollow profile having at least one chamber.

12. A method for producing a bumper beam, the method comprising: shaping an extruded hollow profile having a hollow chamber and an upper side and a lower side, each of the upper side and the lower side having a flange, the flange of the upper side pointing in opposite directions to the flange of the lower side; partially separating the flange by moving a punching tool in a direction from the front side to the rear side of the hollow profile and separating the flange in a central area of ​​the hollow profile; and The central region of the hollow profile is bent in the direction of the front side in order to increase the distance of the flange from the rear side in the central region. 13 . The method of claim 12 , further comprising shaping the flange in the central region such that front surfaces or rear surfaces of the flange face each other in the central region.

14. The method of claim 12, further comprising stretching the central region.

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