Bending crossbeam for a bumper of a motor vehicle

Abstract

Bending cross member (12) for a bumper (10) of a motor vehicle, comprising a base part (20) having a U-profile (22) open downwards in the vehicle's vertical direction (28), and an extension unit (36) formed separately from the base part (20) and movable relative to the base part (20) between a stowage position (32) and a service position (34), which in the stowage position (32) is arranged in a receiving space (38) at least partially bounded by the base part (20), which extends between two legs (24, 26) of the base part (20) forming the U-profile (22), wherein in the service position (34), in which the extension unit (36) is displaced downwards in the vehicle's vertical direction (28) relative to the stowage position (32), at least a partial area (40) of the extension unit (36) is outside the receiving space (38) and is located further down in the vehicle upward direction (28) than the base part (20).

Description

[0001] The invention relates to a bending cross member for a bumper of a motor vehicle according to claim 1.

[0002] DE 10 2023 102 372 A1 discloses a vehicle comprising a vehicle frame, a bumper protected by the vehicle frame, and a bumper extension supported by the bumper and movable downwards relative to the bumper to a raised position and a lowered position.

[0003] Furthermore, a device for absorbing impact energy in the event of a collision of a motor vehicle is known from DE 103 45 749 A1, which can be mounted in the area of ​​a wheel arch of a vehicle wheel of a motor vehicle.

[0004] Furthermore, DE 10 2013 021 346 A1 discloses a method for operating a safety system of a first motor vehicle for collision avoidance and / or collision mitigation, wherein at least one collision parameter describing the possible collision with a second motor vehicle is determined by evaluating environmental data about the environment of the own motor vehicle and ego data about the own motor vehicle, and if at least one collision criterion evaluating the collision parameter is fulfilled, at least one further vehicle system is controlled to carry out a measure.

[0005] DE 10 2017 000 252 A1 relates to a bumper for a vehicle, with a cross member which is connected to a body via at least one fastening device. In this case, at least one adjustment device varies the position of an effective edge of the cross member, at least in the vertical direction of the vehicle (z), depending on predefined criteria.

[0006] JP 2005 7 921 A describes a bumper device. It consists of a bumper whose width can be increased in vehicle height and a collision prediction device for predicting a collision. Preferably, the bumper includes an airbag. This airbag is inflated by a gas generator based on the collision prediction, thus increasing the width of the bumper in vehicle height.

[0007] DE 10 2014 009 942 A1 discloses a front section for a motor vehicle comprising an outer skin, a bumper crossmember arranged behind the outer skin, and at least one auxiliary crossmember. The auxiliary crossmember is movable from a position overlapping with the bumper crossmember into a space extending above or below the bumper crossmember behind the outer skin (11).

[0008] The object of the present invention is to create a bending cross member for a bumper of a motor vehicle, so that the accident behavior of the motor vehicle can be particularly improved.

[0009] This problem is solved according to the invention by a bending cross member for a bumper of a motor vehicle with the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the remaining claims.

[0010] A first aspect of the invention relates to a bending cross member for a bumper of a motor vehicle, or for the motor vehicle itself. The motor vehicle is, for example, a passenger car. Preferably, the motor vehicle, particularly in its fully manufactured state, has the bumper, and in particular the bending cross member. The bumper is, for example, a front or rear bumper.

[0011] The bending crossbeam can also simply be referred to as a bending beam. A main extension direction of the bending crossbeam preferably runs at least substantially parallel to a transverse direction of the vehicle.

[0012] The bending crossbeam has at least one base section, which has a U-profile. In other words, the base section, and in particular a cross-section of the base section, is U-shaped. The base section is specifically designed as a crossbeam, which means that the base section can also be referred to as the first crossbeam element of the bending crossbeam. The U-profile, especially when the bending crossbeam is installed in or on the motor vehicle, is open downwards in the vehicle's vertical direction. The U-profile, or the bending crossbeam, is thus, for example, designed or shaped as a large, upside-down U.

[0013] To significantly improve the vehicle's crash behavior, and in particular its safety, the bending crossbeam has at least one extension unit, separate from the base part and movable relative to the base part between at least one stowed position and at least one operating position, which is distinct from the stowed position. In other words, the extension unit is movable at least between the stowed position and the operating position. In the stowed position, the extension unit is arranged, in particular at least predominantly or completely, in a receiving space that is at least partially, for example at least predominantly and completely, bounded by the base part, in particular directly. In other words, in the stowed position, the extension unit is received in the receiving space that is formed, at least partially, by the base part.Thus, the receiving space extends particularly within the base part, whereby the receiving space is, for example, designed as a cavity. The receiving space extends, particularly in the longitudinal direction of the vehicle, between two legs of the base part that form the U-profile, in particular at least partially, predominantly, or completely. In other words, the receiving space is arranged between the legs of the base part that form the U-profile, at least partially. Thus, in the stowed position, the extension unit is arranged at least partially, in particular predominantly or completely, between the two legs.

[0014] The term "accommodation space" can therefore be understood to mean, in particular, the space between the legs of the U-profile, in which the extension unit is or will be positioned, especially in the stowed position. The fact that the two legs form the U-profile can be understood to mean, in particular, that the U-profile or a U-shape of the base part has the two legs. The stowed position can be understood to mean, in particular, a normal position, which can also be referred to as the normal state. In the operating position, the extension unit is shifted downwards relative to the stowed position, especially in the installed position of the bending cross member in or on the vehicle, in the vehicle's vertical direction, particularly at least partially or completely.This means that to move the extension unit from the stowed position to the operating position, the extension unit must be moved downwards relative to the base unit in the vehicle's vertical direction. In other words, moving the extension unit from the stowed position to the operating position involves moving it downwards in the vehicle's vertical direction. Furthermore, in the operating position, at least a portion of the extension unit, which is located within the receiving space (i.e., inside the receiving space) in the stowed position, is located outside the receiving space and, particularly when the bending cross member is installed in or on the vehicle, is positioned further downwards in the vehicle's vertical direction than the base unit.This means that, in the operating position, at least part of the extension unit is located outside the receiving area and, in the operating position, at least part of the extension unit is positioned further down the vehicle than the base unit. In other words, in the operating position, at least part of the extension unit is located in the vicinity of the base unit, with at least part of the extension unit projecting downwards beyond the base unit in the vehicle's vertical direction. This means that at least part of the extension unit extends further downwards in the vehicle's vertical direction than the base unit. The operating position can be understood, in particular, as a safety position, which can also be referred to as a safety state.

[0015] Because, in the operating position, at least part of the extension unit is positioned outside the storage area and further down in the vehicle's vertical direction than the base unit, the bending cross member is extended downwards in the vehicle's vertical direction by means of the extension unit compared to its stowed position. The extension unit can therefore also be referred to as an extension insert or simply as an extension or bending cross member extension.

[0016] The extension unit is specifically designed as a crossbeam, which can be referred to as a second crossbeam. The extension unit can therefore be understood as a second crossbeam element of the bending crossbeam. For example, the extension unit is designed as a reinforcing plate and / or a reinforcing profile.

[0017] Moving the extension unit between the stow position and the working position can in particular be understood as moving the extension unit from the stow position to the working position and / or from the working position to the stow position.

[0018] The invention is based in particular on the following findings and considerations: Most modern vehicles, for example, have a bending cross member installed in both the front and rear sections. This bending cross member, also known as a flexing beam, can, in the event of a crash, ensure that the forces occurring—that is, the forces caused by the accident—are distributed, deflected, and / or dissipated over as much of the body structure as possible by intentionally deforming the vehicle's body. The aim is, for example, to convert as much crash energy as possible into deformation energy in order to minimize the forces and energy inputs to the vehicle's occupants.The bumper, or rather its crossmember, can only function optimally if both vehicles involved in the accident and their crossmembers are at approximately the same height relative to the road surface. Only then can the two crossmembers—that is, the crossmember of one vehicle and the crossmember of the other—actually meet, allowing both vehicles to fully activate their body-in-white structures. If, for example, the road surface is significantly different, the crossmembers may misalign, causing the vehicles to collide without the maximum possible deformation work being achieved by both bodies. In such a case, it would likely only be the wheels or an engine block in the front that would initiate the intended deformation process.However, this can leave many centimeters of potential crash structure, meaning particularly valuable ones, unused. An example of such an accident would be a collision between a raised SUV and a lowered sports car.

[0019] In contrast, the aforementioned disadvantages can be overcome by means of the bending crossbeam according to the invention. The object of the invention is, in particular, that if the bending crossbeams do not match in height and cannot be adapted to one another, for example, via compression and rebound, then the bending crossbeam according to the invention, which is in particular the bending crossbeam of the higher of the aforementioned vehicles, can be enlarged in order to generate the necessary overlap of the bending crossbeams of the vehicles involved in the accident. The bending crossbeam of the higher vehicle is advantageous for this purpose because ground clearances below the bending crossbeams offer, for example, ample space. Furthermore, the acting gravitational force can be used to amplify the bending crossbeam from its stowed position to its operating position.In the stowed position, for example, at least the aforementioned section of the bending crossbeam according to the invention is located within the receiving space, meaning that in the stowed position, the bending crossbeam, in particular the base part, is not extended downwards in the vehicle's vertical direction. If the downward extension in the vehicle's vertical direction is not required, the base part and the extension unit, for example, form a connected unit that can jointly absorb and / or convert accident-related forces in the form of deformations. In the operating position, however, the bending crossbeam or the base part is extended downwards in the vehicle's vertical direction by the extension unit, meaning that in the operating position, the bending crossbeam extends further downwards, particularly in the vehicle's vertical direction, than in the operating position.Furthermore, the total surface area of ​​the bending crossbeam, designed to absorb accident-related forces, is increased in its operating position compared to its stowed position. This means that if downward extension is required, the bending crossbeam can transform and provide support by moving the extension unit into its operating position. This allows the bending crossbeam to extend into the ground clearance area, thereby creating the possibility for the bending crossbeams of the vehicles involved in the accident to overlap, particularly in the vertical direction.Thus, the extension unit initially remains in its normal state within the detection space, for example, after the vehicle has been installed, until a crash is detected and therefore triggering is necessary. Upon detection of the crash, or triggering, the extension unit can then be moved into its operational position. With the extension unit in its operational position, the two cross members of the vehicles can, for example, align perfectly, allowing both vehicles to fully activate their body-in-white structures. This means that if, for instance, road surfaces differ significantly and the cross members of the vehicles are at risk of missing each other, this can be avoided by moving the extension unit into its operational position, thereby aligning the cross members vertically.This prevents the vehicles from colliding without allowing both car bodies to undergo maximum deformation. Therefore, optimal overlap of the bending cross members of both vehicles can be achieved during the crash. Furthermore, full activation of the body-in-white structures of both vehicles can be ensured during the crash. Overall, it is evident that the bending cross member according to the invention enables the bending beam extension for raised vehicles to achieve better overlap in the event of a crash.

[0020] To further improve vehicle safety, a further embodiment provides that the width of the extension unit, extending transversely in the direction of the vehicle, particularly when the bending cross member is installed in or on the vehicle, is at least half the width of the bending cross member itself. This means that the extension unit, in relation to the vehicle's transverse direction, is at least half the width of the entire bending cross member. In other words, the extension unit encompasses at least half of the lateral extent of the bending cross member. This allows the bending cross member to be brought into particularly good contact with a collision partner by means of the extension unit.For example, the width of the base part, extending in the transverse direction of the vehicle, particularly when the bending cross member is installed in or on a motor vehicle, is at least half, and in particular at least three-quarters, the total width of the bending cross member. For example, the width of the base part corresponds at least substantially to the total width of the bending cross member.

[0021] To move the extension unit into the operating position particularly reliably and / or quickly, a further embodiment provides that the bending crossbeam has at least one drive element by means of which the extension unit can be driven or is driven to move from the stowed position to the operating position. This means that the movement of the extension unit from the stowed position to the operating position can be effected or is effected by means of the drive element. In other words, it is provided that the extension unit can be moved or is moved from the stowed position to the operating position by means of the drive element.

[0022] In a further embodiment, the drive element is designed as a spring element, particularly a mechanical one, via which the extension unit is preferably coupled, at least indirectly or directly, to the base part, particularly by means of a spring or elastic connection. When the extension unit is in its stowed position, the spring element is, for example, in a compressed state in which energy, particularly potential energy, can be stored or is stored by means of the spring element. For example, moving the spring element from the compressed state to an uncompressed or less compressed state is accompanied by moving the extension unit from the stowed position to the operating position. The energy required to move the extension unit from the stowed position to the operating position can be supplied by the energy stored by means of the spring element.The spring element is thus designed, for example, as a pre-tensioned spring element in the stowed position. This means that, for instance, during the installation of the extension unit, the spring element is pre-tensioned, particularly in a controlled manner. The spring element allows the extension unit to be moved into the operating position particularly safely and / or quickly, thereby significantly increasing the safety of the vehicle.

[0023] Alternatively, in a further embodiment, the drive element is designed as an airbag, which can be understood to mean, in particular, an air sac. The airbag is attached to the base part, for example, at least indirectly or directly. Furthermore, it is provided that the airbag can be moved, or is moved, from a storage position to at least one deployment position, which is different from the storage position, for the purpose of directly deploying the extension unit, in order to move the extension unit from the stowed position to the operating position. This means that the airbag can be moved, or is moved, from the storage position to the deployment position in order to deploy the extension unit, in particular mechanically, thereby moving the extension unit from the stowed position to the operating position.In other words, the airbag moves the extension unit downwards in the vehicle's vertical direction and holds it in its operating position. The airbag allows the extension unit to be moved into its operating position particularly safely and / or quickly. Furthermore, it ensures that the extension unit remains securely in its operating position.

[0024] For example, the airbag is arranged or contained within the base part, at least in the storage position, and in particular predominantly or completely. Similarly, the airbag is arranged or contained within the base part, and in the deployment position, particularly at least predominantly or completely. Preferably, the airbag occupies a significantly larger volume in the deployment position compared to the storage position. This volume is preferably contained within the base part. To move the airbag from the storage position to the deployment position, a fluid, in particular a gas, is introduced into the airbag, preferably explosively, and in particular by being blown in. This gas is, for example, air.The gas is supplied, for example, by a gas generator, particularly explosively, which allows the airbag to be moved from its storage position to its deployment position very quickly, i.e., in a very short time. The gas generator is, for example, designed as a pyrotechnic actuator.

[0025] In a further embodiment, the bending crossbeam has at least one locking element by which, particularly with regard to the stowed position and the operating position exclusively, the extension unit is secured against movement from the stowed position, especially into the operating position, particularly unintentionally. In other words, particularly with regard to the stowed position and the operating position exclusively, the movement of the extension unit from the stowed position, especially into the operating position, can be prevented or is prevented by means of the locking element. This means that in the stowed position, when the locking element is in a first state, the movement of the extension unit from the stowed position, especially into the operating position, is prevented.Furthermore, the bending crossbeam preferably has at least one pyrotechnic release element by means of which the extension unit can be, and in particular is, selectively released from the locking element to move it from the stowed position to the operating position. This means that, by means of the pyrotechnic release element, in particular by at least one explosion caused by the release element, the extension unit can be, and is, released from the locking element in order to move the extension unit from the stowed position to the operating position.In other words, it is intended that the securing of the extension unit, or the prevention of its movement from the stowed position, can be specifically prevented or prevented by means of the pyrotechnic triggering element, for example, by the aforementioned explosion. Thus, it is intended, for example, that the locking element can be transferred from the first state to a second state different from the first, by means of the pyrotechnic triggering element, and in particular by means of the aforementioned explosion, in which the aforementioned securing or prevention of the movement of the extension unit is omitted.The locking element and the pyrotechnic triggering element thus ensure that, for example, the extension unit is only moved into the operating position when it actually needs to be moved, and / or in a particularly fast manner.

[0026] To enable particularly reliable and / or rapid movement of the extension unit into the operating position, a further embodiment provides that the locking element can be destroyed, at least partially, and in particular predominantly or completely, by means of the pyrotechnic release element, in order to release the extension unit from the locking element. This allows the extension unit to be moved from the stowed position to the operating position. In other words, the activation of the pyrotechnic release element, particularly by detonation, results in the destruction, at least partially, of the locking element. This allows the extension unit to be released from the locking element, i.e., decoupled from it.Thus, in the second state, the locking element is at least partially destroyed by the explosion. In the first state, the aforementioned destruction of the locking element does not occur. This means that in the first state, the locking element is not destroyed, particularly by the explosion. In other words, the locking element is intact in the first state. The explosion can be understood to mean, in particular, a preferably controlled explosion, for example, by means of at least one pyrotechnic charge in the triggering element. Thus, the pyrotechnic triggering element can contain the pyrotechnic charge, for example, in the form of explosives.

[0027] To ensure that the extension unit is held securely to the base in the stowed position and that moving the extension unit into the operating position in the event of an accident is particularly reliable and / or safe, the locking element is designed as a screw element. In other words, specifically with regard to the stowed and operating positions, the extension unit is fixed in the stowed position by means of the screw element, specifically screwed to the base by means of the screw element. This fixing, specifically this screwing, is preferably omitted in the operating position, or in the second state. Therefore, in the first state, the extension unit is screwed to the base by means of the screw element. The locking element is thus, for example, designed as a self-tapping screw.To secure the extension unit in position and maintain the preload of the spring element, the extension unit can be firmly mounted using at least one screw element. This screw element can be the aforementioned explosive screw, which can be pyrotechnically separated.

[0028] To enable particularly reliable movement of the extension unit into the operating position and / or particularly reliable, and especially precisely defined, fixing in the operating position, a further embodiment provides that at least one stop element, for example designed as a braking element, is arranged directly on the base part. The stop element can be designed separately from the base part or it can be formed integrally with the base part. Furthermore, the extension unit has at least one stop area by which the extension unit, particularly with regard to the operating position and the stowed position exclusively, is supported in the operating position, especially in the installation position of the bending cross member in or on the motor vehicle, downwards in the vehicle's vertical direction, for example at least indirectly or directly, against the stop element.In other words, when the extension unit is moved from its normal position to its safety position, it collides with the stop element of the base unit via the stop area. This causes the extension unit, particularly in the operating position, to rest against the stop element, for example, directly, via the stop area. An opening, formed in particular by the U-profile, through which the extension unit can be moved from the storage position to the operating position, is, for example, narrowed by the stop element. This means that the stop element can form an undercut, at least partially, preventing the extension unit from sliding completely out of the narrowed opening in the operating position.

[0029] To significantly increase the mechanical strength of the bending crossbeam, particularly the extension unit, the extension unit is, for example, designed as a single piece. This allows for a particularly low manufacturing effort for producing the bending crossbeam, especially the extension unit. Alternatively, the extension unit is, for example, designed as a multi-part unit. This means that the extension unit has several separately manufactured extension sections. This is particularly advantageous if the bending crossbeam, especially the base section, is, for example, slightly curved.With only a single, especially one-piece, extension section, there could be a risk of it jamming against the base section when moving into the operating position, for example, when ejecting from the base section. This risk can be significantly reduced by using multiple sections, as several extension sections of the extension unit can be arranged side-by-side in the transverse direction of the vehicle, allowing the extension unit to be adapted to curved shapes.

[0030] Another aspect concerns a method for operating a bumper for a motor vehicle with at least one bending cross member according to the invention and / or a method for operating a motor vehicle which has the bumper with the bending cross member according to the invention. Advantages and advantageous embodiments of the invention are to be regarded as advantages and advantageous embodiments of the further aspect and vice versa. In the method, it is provided, for example, that, particularly in the event of an accident of the motor vehicle, that is, for example, when an impending or an actual accident is detected by means of at least one accident detection device of the motor vehicle, the extension unit is moved from the stowed position to the operating position.

[0031] Further advantages, features, and details of the invention will become apparent from the following description of a preferred embodiment and from the drawings. The features and combinations of features mentioned above in the description, as well as those mentioned below in the figure description and / or shown in the figures alone, can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the invention.

[0032] This shows: Fig. 1 a schematic perspective view of a bumper with a bending crossbeam according to the invention; and Fig. 2 a schematic partial sectional view of a bending crossbeam according to the invention with an extension unit which is in a stowed position; and Fig. 3 a schematic and perspective partial sectional view of a bending crossbeam according to the invention with an extension unit which is in a stowed position; and Fig. 4 a schematic partial sectional view of a bending crossbeam according to the invention with an extension unit which is in a service position; and Fig. 5 a schematic and perspective partial sectional view of a bending crossbeam according to the invention with an extension unit which is in a service position; and Fig. 6 a schematic and perspective partial sectional view of a bending crossbeam according to a further embodiment of the invention with an extension unit which is in a stowed position; and Fig. 7 a schematic and perspective partial sectional view of a bending crossbeam according to a further embodiment with an extension unit which is in a service position.

[0033] In the figures, identical or functionally equivalent elements are provided with the same reference symbols.

[0034] Fig. Figure 1 shows a schematic perspective view of a bumper 10 for a motor vehicle. The term bumper 10 can refer in particular to a bumper system. The bumper 10 is designed, for example, as a front or rear bumper of the motor vehicle.

[0035] As in Fig. As shown in Figure 1, the bumper 10 has at least one bending cross member 12. The bumper 10, in particular the bending cross member 12, extends, for example, from a first side of the vehicle in the transverse direction to a second side of the vehicle that differs from the first side.

[0036] For example, the bumper 10 has two longitudinal members 14, which are in particular designed separately from one another and are spaced apart from each other in the transverse direction 16 of the vehicle. For example, the longitudinal members 14 are connected to each other via the bending cross member 12, in particular directly. For example, the longitudinal members 14 are designed separately from the bending cross member 12. For example, the bumper 10, in particular each longitudinal member 14, has at least one mounting area 18 by which the bumper 10 can be attached, at least indirectly, in particular directly, to a body, for example, to at least one body component of the vehicle, for example, at the front or rear of the vehicle. The body is, for example, designed as a self-supporting body.

[0037] As in Fig. As illustrated in Figure 1, the bending crossbeam 12 preferably extends at least substantially in the transverse direction 16 of the vehicle. Thus, for example, a principal extension direction of the bending crossbeam 12 extends at least substantially in the transverse direction 16 of the vehicle, and in particular at least substantially parallel to the transverse direction 16 of the vehicle. For example, the bending crossbeam 12 is curved. The curvature is, for example, a convex curvature with respect to the motor vehicle.

[0038] In Fig. Figure 2 shows the bending crossbeam 12 in a schematic partial sectional view. Furthermore, in Fig. Figure 3 shows a schematic and perspective partial sectional view of the bending crossbeam 12. The bending crossbeam 12 has at least one base section 20, which has a U-profile 22. The base section 20, in particular the U-profile 22, therefore has two legs 24, 26, spaced apart from each other, in particular at least in the longitudinal direction of the vehicle, which in particular at least partially form the U-profile 22. The legs 24, 26 project, for example, downwards, in particular in the vertical direction 28 of the vehicle, for example obliquely or perpendicularly, from a base element 30 of the base section 20, in particular of the U-profile 22. The legs 24, 26 connect, for example, at least indirectly, in particular directly, to the base element 30. As shown in the Fig. 2 and Fig. As can be seen particularly well in Figure 3, the U-profile 22 is open downwards in the vehicle's vertical direction 28. Therefore, the U-profile 22 is closed upwards in the vehicle's vertical direction 28. This means that the base element 30, which is designed, for example, as a base wall, is arranged on an upper surface of the base part 20, in particular the bending crossbeam 12, which points upwards in the vehicle's vertical direction 28.

[0039] In order to significantly improve the vehicle's crash behavior, the bending crossbeam 12 has at least one extension unit 36, which is designed separately from the base part 20 and movable relative to the base part 20 between a stowed position 32 and a working position 34. This extension unit 36 ​​is, for example, designed as an extension part. The extension unit 36 ​​is, for example, attached, in particular at least indirectly or directly, to the base part 20, in particular to the base element 30, and is movable at least between the stowed position 32 and the working position 34. Fig. 2 and Fig. In position 3, the extension unit 36 ​​is located in the stowed position 32. Between the legs 24, 26, at least a receiving space 38 extends, which is at least partially, in particular predominantly or completely, bounded by the base part 20, in particular by the legs 24, 26 and the base element 30, and in which the extension unit 36 ​​is arranged or received, in particular at least predominantly or completely, in the stowed position 32. Thus, in particular in the stowed position 32, the extension unit 36 ​​is received at least partially, in particular predominantly or completely, within the base part 20. For example, in the stowed position 32, the extension unit 36 ​​does not protrude out of the receiving space 38, in particular out of the base part 20. The extension unit 36 ​​is designed, for example, as an insert, i.e., as an insert part.

[0040] In Fig. Figure 4 shows the bending crossbeam 12 in a schematic partial sectional view and in Fig. Figure 5 shows the bending crossbeam 12 in a schematic and perspective partial section view, where in the Fig. 4 and Fig. 5. The extension unit 36 ​​is in the operating position 34. In the operating position 34, the extension unit 36 ​​is displaced downwards in the vehicle's vertical direction 28 relative to the stowed position 32. This means that one direction of movement for moving the extension unit 36 ​​from the stowed position 32 to the operating position 34 is downwards in the vehicle's vertical direction 28. For example, the direction of movement runs at least substantially parallel to the vehicle's vertical direction 28. In the operating position 34, at least a partial section 40 of the extension unit 36 ​​is located outside the receiving space 38 and further down in the vehicle's vertical direction 28 than the base part 20, in particular than the legs 24, 26. In the stowed position 32, this partial section 40 is located in the receiving space 38, that is, in particular, within the base part 20.

[0041] By moving the extension unit 36 ​​from the stowed position 32 to the operating position 34, the height 42 of the bending cross member 12 extending in the vehicle's vertical direction 28 can be increased compared to the stowed position 32. This height 42 is therefore greater in the operating position 34 than in the stowed position 32. This allows the bending cross member 12 to be particularly well adapted to a collision partner of the vehicle, for example, to a bumper or its bending cross member of another vehicle. This results, for example, in a particularly good overlap of the bending cross member 12 in the vehicle's vertical direction 28 with the other vehicle, especially its bumper or its bending cross member. The "other vehicle" can be understood to be, in particular, another vehicle with which the vehicle collides in an accident.

[0042] The width of the extension unit 36 ​​and / or the base part 20 extending in the transverse direction 16 of the vehicle is preferably at least half as large as the total width 44 of the bending crossbeam 12 extending in the transverse direction 16 of the vehicle.

[0043] Preferably, the bending crossbeam 12 has at least one drive element 46 by means of which the extension unit 36 ​​can be driven or is driven to move from the stowed position 32 to the operating position 34. Fig. In the embodiments shown in Figures 2 to 5, the drive element 46 is designed as a spring element 48, which is, for example, designed as a coil spring. In this embodiment, the extension unit 36 ​​is coupled to the base part 20, in particular to the base element 30, at least indirectly, and in particular directly, via the spring element 48. Thus, in this embodiment, the extension unit 36 ​​is connected to the base part 20, in particular to the base element 30, via the spring element 48. In this embodiment, the spring element 48 is in a compressed state when the extension unit 36 ​​is in the stowed position 32. When the spring element 48 expands, that is, when the spring element 48 moves from the compressed state to a non-compressed or less compressed state, i.e., for example, an expanded state, the extension unit 36 ​​moves from the stowed position 32 to the operating position 34. As shown, for example, in Figure 2 to 5, the extension unit 36 ​​is then moved from the stowed position 32 to the operating position 34. Fig. 3. Several such spring elements 48 are provided, for example, which are particularly easy to see.

[0044] Preferably, the bending crossbeam 12 has at least one locking element 50 by means of which, in the stowed position 32, the extension unit 36 ​​is secured against movement from the stowed position 32, in particular into the operating position 34. For example, several such locking elements 50 are provided. Thus, the bending crossbeam 12 in this case has several locking elements 50 by means of which, in the stowed position 32, the extension unit 36 ​​is secured against movement from the stowed position 32, in particular into the operating position 34. The locking element 50 is, for example, designed as a fastening element by means of which, or via which, the extension unit 36 ​​is attached, for example directly, to the base part 20, in particular the base element 30.In the present case, the fastening element, or the respective fastening element, is designed as a screw element 52, or the respective screw element 52, by means of which, particularly with regard to the operating position 34 and the storage position 32, the extension unit 36 ​​is screwed, in particular directly, to the base part 20, for example the base element 30, in the storage position 32. The screw element 52, or the respective screw element 52, is, for example, a screw.

[0045] Furthermore, the bending crossbeam 12 preferably has at least one pyrotechnic release element 54, by means of which the extension unit 36 ​​can be released from the locking element 50 to move it from the stowed position 32 to the operating position 34. For example, several such pyrotechnic release elements 54 are provided, wherein, for example, at least one of the pyrotechnic release elements 54 is assigned to the respective locking element 50.In the present case, the locking element 50, or the respective locking element 50, is at least partially, in particular predominantly or completely, destructible by means of a pyrotechnic release element 54, or the respective pyrotechnic release element 54, in order to release the extension unit 36 ​​from the locking element 50, or the respective locking element 50. Accordingly, in the present case, the locking element 50, that is, the screw element 52, or the respective locking element 50, that is, the respective screw element 52, is designed as an explosive screw, or the respective explosive screw.

[0046] The term "detonating screw" refers specifically to a special fastening element that can be detonated in a controlled manner when needed. A detonating screw typically consists of a metal tube that is at least partially filled with an explosive and has a screw-like shape at one end. The explosive can be the pyrotechnic trigger element 54. By using an electric detonator or other detonation mechanism, the detonating screw can be deliberately detonated, thereby releasing the fastening element. Thus, the pyrotechnic trigger element 54, in particular, incorporates a detonator, such as an electric one.

[0047] For example, the motor vehicle has at least one accident detection device for recording the accident, in particular an impending or actual accident. This means that the accident can be recorded or is recorded by means of the accident detection device. The detection device has, for example, at least one camera for recording the accident. Alternatively or additionally, the detection device has, for example, at least one receiving device for receiving at least one signal characterizing the accident from the other motor vehicle. This means that the signal, which has been transmitted, for example, by the other motor vehicle, can be received or is received by means of the receiving device. The signal characterizes, for example, the position, in particular the height, of a bumper, in particular a cross member, of the other motor vehicle, wherein this bumper of the other motor vehicle is, in particular, facing the motor vehicle.Furthermore, the motor vehicle has, for example, at least one electronic computing device by means of which, depending on the detected accident and / or depending on the detected signal, the pyrotechnic triggering element 54 can be controlled or is controlled in order to cause the extension unit 36 ​​to move from the stowed position 32 to the operating position 34.Thus, if car-to-car communication and / or the camera detects that a configuration of the vehicles involved in the accident, i.e., a configuration of the vehicle with the other vehicle, is such that the bending crossbeams of the vehicles do not overlap in their height, but rather, for example, a wide intrusion of the two vehicles in the form of the vehicle and the other vehicle is to be expected, the vehicle with a higher bending crossbeam position, i.e., for example, the vehicle, is given a control command to separate the screw elements 52 pyrotechnically by means of the pyrotechnic triggering element 54.This would mean, for example, that the extension unit 36 ​​would no longer be rigidly connected to the rest of the bending crossbeam 12, i.e., in this case, to the base part 20. As a result, the preload induced by the spring elements 48, and, for example, the effect of graphitic force, would push the extension unit 36 ​​downwards in the vehicle's upward direction 28 towards the opening of the U-profile 22, i.e., towards the open end of the U-profile 22. It would also be conceivable, if no or no unambiguous car-to-car communication is possible, to always trigger the release element 54 in the event of an unavoidable crash. In the event of a false triggering, the bending crossbeam 12 would simply need to be re-secured with new explosive bolts after the extension unit 36 ​​has been pre-tensioned and positioned.

[0048] In the present case, the base part 20 has an opening 58, in particular a through-opening, which is formed, for example, by the legs 24, 26. The receiving space 38 opens, for example, through the opening 58 into the surroundings of the bending crossbeam 12, in particular the base part 20. This allows the extension unit 36 ​​to be moved out of the receiving space 38 via the opening 58. As shown in the Fig. 4 and Fig. As shown in Figure 5, in the operating position 34, the extension unit 36 ​​is at least partially guided through the opening 58. In the storage position 32, this passage is omitted, for example.

[0049] For example, at least one stop element 60, which is formed separately from the base part 20, is arranged, and in particular attached, to the base part 20. In the present case, at least one second stop element 62, which is formed separately from the base part 20 and the stop element 60, is arranged on the base part 20. The respective stop elements 60 and 62 can also be referred to as braking elements. The stop element 60 can also be referred to as the first stop element 60. The first stop element 60 is arranged, for example, on a rearward-facing side of the base part 20 that points in the longitudinal direction of the vehicle. The second stop element 62 is arranged, for example, on a frontward-facing side of the base part 20 that points in the longitudinal direction of the vehicle.Thus, for example, the respective stop elements 60 and 62 are mounted on the underside of the base part 20, which points downwards in the vehicle's vertical direction 28, on both the rear and front sides. The respective stop elements 60 and 62 are, for example, screwed to the base part 20, i.e., connected by means of screws 64. The first stop element 60 is, for example, attached to one of the legs 24, and the second stop element 62 is, for example, attached to the second leg 26. Thus, for example, both a rear-side brake element in the form of the first stop element 60 on the rear and a front-side brake element in the form of the second stop element 62 on the front are attached to the bending crossbeam 12, in particular to the base part 20, with screws 64 during the assembly process, for example, after the extension unit 36 ​​has been inserted.

[0050] Furthermore, the extension unit 36 ​​has at least one stop area 66, 68, by which the extension unit 36, in the operating position 34 in the vehicle's upward direction 28, is supported downwards, in particular directly, against the respective stop element 60, 62. For example, a first stop area 66 is supported against the first stop element 60, and a second stop area 68 is supported against the second stop element 62. The stop elements 60, 62 form, for example, an undercut, in particular to hold the extension unit 36, in the operating position 34, at least partially within the receiving space 38, that is, within the base part 20. This undercut narrows the opening 58. The respective stop area 66, 68 is, for example, designed as a respective cross-sectional enlargement of the extension unit 36.This means that the stop areas 66, 68, for example, form the cross-sectional enlargement of the extension unit 36. The respective stop area 66, 68 is preferably designed to correspond with the respective stop element 60, 62. This means that, in this case, the extension unit 36 ​​is designed in such a way that, thanks to the undercut, it cannot slide out of the opening 58 narrowed by the front brake element and rear brake element.

[0051] In the Fig. 6 and Fig. Figure 7 shows the bending crossbeam 12 in a respective schematic and perspective partial sectional view according to a further embodiment, in which the drive element 46 is designed as an airbag 70. The airbag 70 can be moved from a storage position 72 to an deployment position 74 for deploying the extension unit 36, in order to move the extension unit 36 ​​from the stowed position 32 to the operating position 34. Fig. In position 6, the airbag 70 is in storage position 72, which places the extension unit 36 ​​in stow position 32. Fig.In position 7, the airbag 70 is in the deployment position 74, which places the extension unit 36 ​​in the operating position 34. The airbag 70 can therefore be ignited, for example, after the explosive screws, to move the extension unit 36 ​​downwards in the upward direction of the vehicle and to hold it in its new position 34.

[0052] For example, at least one protective element 76 is arranged on the underside of the bending crossbeam 12, in particular the base part 20, which points downwards in the vehicle's vertical direction 28. This protective element 76 closes the opening 58, in particular completely, for example, in the stowed position 32. The protective element 76 is thus designed, for example, as a cover. The protective element 76 prevents dirt or foreign objects from entering the receiving space 38 and, for example, clogging the opening 58, which is designed, in particular, as a channel, in the U-shaped profile 22 of the bending crossbeam 12. The protective element 76 is made, for example, of a plastic material. The protective element 76 is screwed to the base part 20, in particular to the respective stop elements 60, 62, for example, by means of the screws 64.

[0053] To increase the stiffness of the bending crossbeam 12 in a particularly weight-efficient manner, the respective leg 24, 26 and / or the base element 30 are designed as hollow profiles, which, for example, have at least one intermediate wall. Furthermore, the extension unit 36 ​​is designed as a hollow profile, which, for example, has several intermediate walls. In particular, each hollow profile has at least one hollow chamber.

Claims

[1] Bending cross member (12) for a bumper (10) of a motor vehicle, comprising a base part (20) having a U-profile (22) open downwards in the vehicle's vertical direction (28), and an extension unit (36) formed separately from the base part (20) and movable relative to the base part (20) between a stowage position (32) and a service position (34), which in the stowage position (32) is arranged in a receiving space (38) at least partially bounded by the base part (20), which extends between two legs (24, 26) of the base part (20) forming the U-profile (22), wherein in the service position (34), in which the extension unit (36) is displaced downwards in the vehicle's vertical direction (28) relative to the stowage position (32), at least a partial area (40) of the extension unit (36) is outside the receiving space (38) and is positioned further down in the vehicle upward direction (28) than the base part (20), with a locking element (52) by means of which the extension unit (36) is secured against movement from the stowed position (32) and a pyrotechnic release element (54) by means of which the extension unit (36) can be released from the locking element (50) to move it from the stowed position (32) to the operating position (34), wherein the locking element (50) can be destroyed at least partially by means of an explosion using the pyrotechnic release element (54) in order to release the extension unit (36) from the locking element (50), characterized by , that the locking element (50) is designed as a screw element (52). [2] Bending crossbeam (12) according to claim 1, characterized by, that the width of the extension unit (36) extending in the transverse direction (16) of the vehicle is at least half as large as the total width (44) of the bending crossbeam (12) extending in the transverse direction (16) of the vehicle. [3] Bending crossbeam (12) according to claim 1 or 2, characterized by a drive element (46) by means of which the extension unit (36) can be driven to move from the storage position (32) to the operating position (34). [4] Bending crossbeam (12) according to claim 3, characterized by , that the drive element (46) is designed as a spring element (48) via which the extension unit (36) is preferably coupled to the base part (20). [5] Bending crossbeam (12) according to claim 3 characterized by, that the drive element (46) is designed as an airbag (70) which can be moved from a storage position (72) to an deployment position (74) to deploy the extension unit (36) in order to move the extension unit (36) from the storage position (32) to the operating position (34). [6] Bending crossbeam (12) according to one of the preceding claims, characterized by , that at least one stop element (60, 62) is arranged on the base part (20) and the extension unit (36) has at least one stop area (66, 68) over which the extension unit (36) is supported downwards in the vehicle upward direction (28) on the stop element (60, 62) in the operating position (34). [7] Bending crossbeam (12) according to one of the preceding claims, characterized by that the extension unit (36) is designed as a single piece or as multiple pieces.

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