Front-end structure for a body of a motor vehicle

Abstract

The invention relates to a front-end structure (10) for a body of a motor vehicle, the front-end structure having longitudinal members (12) each of which comprises a front and a rear deformation element (20, 22) in its direction of extent, and between the deformation elements there is a respective middle length region (24) of the corresponding longitudinal member (12), the respective middle length region (24) of the associated longitudinal member (12) being designed as a bending point (K) in the event of an accident-related application of force to the corresponding longitudinal member (12).

Description

[0001] Mercedes-Benz Group AG Mr. Thoms

[0002] October 1, 2025

[0003] Front structure for the body of a motor vehicle

[0004] The invention relates to a front structure for a body of a motor vehicle according to the preamble of claim 1.

[0005] From DE 102013 015615 A1, a front-end structure for a motor vehicle body is already known, in which the longitudinal members of a main longitudinal member plane have a front and a rear deformation element in their extension direction, between which a respective central longitudinal section of the corresponding longitudinal member is arranged. This central longitudinal section of the two longitudinal members is designed as a respective stiffening section, between which a torsion bar of a torsion stabilizer is arranged. Each longitudinal member is designed such that in the event of an impact it is deformed essentially only in the area of ​​the deformation sections, but not in the area of ​​the stiffening section.In the stiffening section, the torsion bar of the rotary stabilizer can thus be mechanically and stably attached to the longitudinal beams, so that it can be ruled out that said torsion bar can come loose in the event of a collision-related deformation of the longitudinal beam.

[0006] The object of the present invention is to create a front-end structure of the type mentioned above which enables more efficient energy absorption in frontal collisions.

[0007] This problem is solved according to the invention by a front-end structure with the features of claim 1. Advantageous embodiments with expedient further developments of the invention are specified in the dependent claims. The front-end structure according to the invention for a car body comprises respective longitudinal members of a main longitudinal member plane, which in their extension direction have a front and a rear deformation element, between which a respective central longitudinal section of the corresponding longitudinal member is arranged.

[0008] To enable more efficient energy absorption of the front structure in frontal collisions, the central section of the corresponding longitudinal member is designed as a buckling point in the event of an impact force. By introducing a main load path with two series-connected energy absorption elements / crash boxes and a central buckling point, improved safety of the front structure can be achieved, resulting in more effective energy absorption in frontal collisions and thus increasing the safety of vehicle occupants.

[0009] The use of two energy absorption elements / crash boxes in series enables significantly more efficient energy absorption compared to conventional systems, resulting in improved protection. Furthermore, the defined folding and buckling of the energy absorption elements / crash boxes allows for controlled deformation with a defined force-displacement ratio, leading to better predictability of the deformation behavior. This arrangement enables effective energy absorption because the two crash boxes work together to absorb and distribute the kinetic energy of the impact.

[0010] The invention can be implemented using steel, aluminum, or other suitable materials, allowing for flexibility in material selection and potential weight savings.

[0011] Overall, the invention leads to improved frontal impact protection with a multitude of benefits for vehicle occupants and higher efficiency in energy absorption.

[0012] In an advantageous embodiment of the invention, the two longitudinal beams are connected to each other via a transverse structure, which is arranged in the area of ​​the respective bending points. The transverse structure provides particularly good support for the deformation elements and the central length section with the bending point of each longitudinal beam, so that its deformation behavior can be reliably controlled.

[0013] In this context, it has proven further advantageous if the transverse structure has two crossbeams, one of which is arranged in the longitudinal direction of the vehicle in front of the respective articulation point and the other of which is arranged in the longitudinal direction behind the respective articulation point. This also results in particularly good support of the deformation elements and the central length section with the articulation point for each longitudinal beam, so that its deformation behavior can be reliably adjusted.

[0014] Furthermore, it has proven advantageous for the crossbeams of the transverse structure to be arched, and especially for the crossbeams of the transverse structure to be arched in the opposite direction. These measures also serve to provide particularly good support for the deformation elements and the central longitudinal section with the buckling point of each longitudinal beam.

[0015] In a further embodiment of the invention, the respective deformation elements and the respective central length section of the corresponding longitudinal beam are connected to one another via a respective bracket. The positive-locking connection of the energy absorption elements / crash boxes via a rigid bracket ensures a robust and reliable structure that can withstand even demanding collision scenarios.

[0016] This applies in particular if, in a further advantageous embodiment of the invention, the crossbeams of the transverse structure are connected via the respective console to the central length area and the respective deformation element.

[0017] Finally, it has proven advantageous for the rear deformation element of the respective longitudinal member to connect to an end wall cross member. This results in particularly favorable support of the rear deformation element of the respective longitudinal member against the passenger compartment, allowing its deformation behavior to be reliably adjusted. Further advantages and details of the invention will become apparent from the following description of a preferred embodiment and from the drawing. 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 figure 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.

[0018] The single figure shows a partial top view of a front structure for a car body with one of two longitudinal beams.

[0019] According to the single figure, a front-end structure 10 for a passenger car body comprises a longitudinal member 12 of a main longitudinal member plane on each side of the vehicle. In the present case, the left longitudinal member 12, viewed in the forward direction, is shown, with an identical longitudinal member arranged symmetrically on the opposite side of the vehicle, although this is not visible here.

[0020] Of the passenger cell 14 which extends to the rear in the longitudinal direction of the vehicle, only a front wall cross member 16 extending in the area of ​​a front front wall 14 is recognizable, on which the two longitudinal beams 12 are supported to the rear or on which they are attached.

[0021] At the front, a bumper cross member 18 is attached and supported to the two longitudinal members 12, which extends over at least approximately the entire width of the vehicle.

[0022] Each of the two longitudinal beams 12 comprises a front deformation element 20 and a rear deformation element 22, which are also referred to as crash boxes, relative to their longitudinal direction in the vehicle. In this context, the term "comprising" means that each longitudinal beam 12 is assigned a front and a rear deformation element, with the front deformation element 20 being located in front of the longitudinal beam 12 (viewed in the forward direction of travel of the vehicle) and the rear deformation element 22 being located behind the longitudinal beam 12. The front and rear deformation elements are typically individual components that are coupled or connected to the longitudinal beam 12.The deformation elements 20, 22 / crash boxes are each a defined deformable component which, in the event of an accident-related force being applied, especially in the direction of the longitudinal extension of the longitudinal member 12, helps to absorb the impact energy through its deformation, thereby reducing the forces acting on a vehicle occupant and protecting other body structures in the front of the vehicle from damage or preventing excessive damage, thus reducing repair costs.

[0023] Between the two deformation elements 20, 22 of the respective longitudinal beam 12, a respective central length section 24 of the corresponding longitudinal beam is arranged, which is designed as a buckling point K in the event of an impact on the corresponding longitudinal beam 12 with an accident-related force, as indicated by an arrow K.

[0024] The front deformation element 20, the rear deformation element 22, and the central longitudinal section 24 of the corresponding longitudinal beam 12 are connected to each other via respective brackets 26 and 28. Since the brackets 26 and 28 are very rigid, a highly reliable and robust structure of the respective longitudinal beam 12 can be achieved. This arrangement enables effective energy absorption, as the two deformation elements 20 and 22 work together to absorb and distribute the kinetic energy of the impact.

[0025] The two longitudinal beams 12 on each side of the vehicle are also connected to each other via a transverse structure 30, which is arranged in the area of ​​the respective bending points K. In this case, the transverse structure 30 comprises two crossbeams: a front crossbeam 32, which is arranged in the longitudinal direction of the vehicle in front of the respective bending point K, and a rear crossbeam 34, which is arranged in the longitudinal direction of the vehicle behind the respective bending point K.

[0026] The two crossbeams 32, 34 of the transverse structure 30 are arched, specifically in opposite directions. This means that the two crossbeams 32, 34 are positioned closer to each other in a central area of ​​the front structure 10, relative to the vehicle's longitudinal direction, than in the area of ​​the respective longitudinal beam 12. Furthermore, the two crossbeams 32, 34 of the transverse structure 30 are connected to the central longitudinal section 24 and the respective deformation element 20, 22 via the respective brackets 26, 28. More precisely, the front crossbeam 32 is connected to the respective front bracket 26, and the rear crossbeam 34 is connected to the respective rear bracket 28 of the corresponding longitudinal beam 12.

[0027] Finally, it becomes clear that in the present case the front deformation element 20 of the respective longitudinal member 12 connects directly to the bumper cross member 18 in the longitudinal direction of the vehicle and that the rear deformation element 22 of the respective longitudinal member 12 connects directly to the front wall cross member 16.

[0028] If, for example, the vehicle is subjected to a force F in the area of ​​the respective longitudinal member 12 during a frontal collision, the respective central length section 24 of the associated longitudinal member 12 is designed as a buckling point K. By introducing a main load path with two energy absorption elements 20, 22 connected in series and a central buckling point K, improved safety of the front-end structure can be achieved with more effective energy absorption in frontal collisions, thus increasing the safety of the vehicle occupants.

[0029] The use of two energy absorption elements 20, 22 in series enables significantly more efficient energy absorption compared to conventional systems, resulting in improved protection. Furthermore, the defined folding and buckling of the energy absorption elements 20, 22 allows for controlled deformation with a defined force-displacement level, leading to better predictability of the deformation behavior. This arrangement enables effective energy absorption because the two deformation elements 20, 22 work together and their deformation behavior can be coordinated to optimally absorb and distribute the kinetic energy of the impact. This results in significantly more effective energy absorption and reduces the stress on the components over time, as the forces generated can be dissipated in a more controlled manner.

[0030] In a particularly advantageous embodiment of the motor vehicle according to the invention, the respective front and rear deformation elements 20, 22, as well as the buckling point K, are coordinated with respect to their deformation properties such that, in the event of an accident-related force being applied to the corresponding longitudinal member in the direction of its longitudinal extension and upon exceeding a defined limit force, the front deformation element 20 first deforms in an energy-absorbing manner before the buckling point K is triggered and the rear deformation element 22 is activated. After the deformation element 20 has deformed accordingly and may—but not necessarily—already be deformed to its limit, i.e., it can no longer be compressed further, the buckling point K is then triggered after the front deformation element 20 if the accident-related force continues, while the rear deformation element 22 continues to withstand the force.Finally, after the buckling point K is triggered, the rear deformation element 22 is deformed in an energy-absorbing manner.

[0031] In a particularly advantageous embodiment of the vehicle according to the invention, the activation of the front deformation element 20 occurs temporally prior to the longitudinal member 12 and the rear deformation element 22, and energy absorption preferably takes place by the deformation element 20 folding in the direction of the longitudinal center axis of the longitudinal member 12, i.e., in the x-direction of the vehicle's coordinate system. The crash space enclosed by the compression / folding of the front deformation element 20 is used for lower-speed crash requirements. In a preferred embodiment, the front deformation element 20 is mounted or remains in the console 26 until it is completely deformed. Upon sustained, accident-induced force, energy absorption is subsequently achieved by buckling in the longitudinal member 12 in the region of the buckling point K and bending of the cross member 32.The crossbeams 32, 34 enable optimal buckling kinematics of the longitudinal beam 12 by providing lateral guidance in the transverse direction of the vehicle, i.e., in the y-direction of the vehicle's coordinate system. Buckling in the longitudinal beam 12 and deflection of the crossbeam 32 prevent block formation in the x-direction between bracket 26 and bracket 28. If the impact continues, the rear deformation element 22 is activated, absorbing energy by deforming axially (x-direction), preferably by means of bulging. The rear deformation element 22 is subjected to axial (x-direction) loading via the bracket 28. This allows for more effective energy absorption compared to buckling kinematics. In the embodiment of the vehicle shown in the figure, the rear deformation element 22 is mounted on the front bulkhead and preferably also on floor structures of the vehicle body.Extensive deformation results in block formation in the longitudinal direction (x-direction) of the vehicle by the console 2, the rear deformation element 22, and the front wall. The forces generated by this block formation are at least partially absorbed by a front wall cross member (not shown) and transferred into the floor structures.

[0032] In the present case, deformation elements 20, 22 made of both steel and aluminum alloys and in various designs, for example as sheet metal shell components, extruded parts, or the like, can be used and offer a versatile solution for frontal impact protection in various vehicle types. The brackets 26, 28 can, for example, be designed as cast components made of a steel or aluminum alloy. Other manufacturing and construction methods are also conceivable.

Claims

Mercedes-Benz Group AG Mr. Thoms October 1, 2025 Patent claims 1. Front structure (10) for a car body, with longitudinal members (12), each of which has a front and a rear deformation element (20, 22) in its extension direction, between which a respective central length section (24) of the corresponding longitudinal member (12) is arranged, characterized in that the respective central length section (24) of the associated longitudinal member (12) is designed as a buckling point (K) in the event of an accident-related force being applied to the corresponding longitudinal member (12).

2. Front structure (10) according to claim 1, characterized in that the two longitudinal beams (12) are connected to each other via a transverse structure (30) which is arranged in the area of ​​the respective bending points (K).

3. Front structure (10) according to claim 2, characterized in that the transverse structure (30) has two cross members (32, 34), one of which is arranged in the longitudinal direction of the vehicle in front of the respective bending point (K) and the other cross member (32, 34) is arranged in the longitudinal direction of the vehicle behind the respective bending point (K).

4. Front structure (10) according to claim 3, characterized in that the crossbeams (32, 34) of the transverse structure (30) are arched.

5. Front structure (10) according to claim 3 or 4, characterized in that the respective deformation elements (20, 22) and the respective central length region (24) of the corresponding longitudinal beam (12) are connected to each other via a respective console (26, 28).

6. Front structure (10) according to claim 6, characterized in that the crossbeams (32, 34) of the transverse structure (30) are connected via the respective console (26, 28) to the central length section (24) and the respective deformation element (20, 22).

7. Front structure (10) according to one of claims 4 to 6, characterized in that the crossbeams (32, 34) of the transverse structure (30) are formed in an arc shape opposite to each other.

8. Front structure (10) according to one of the preceding claims, characterized in that the rear deformation element (22) of the respective longitudinal beam (12) connects to an end wall crossbeam (16).

9. Front structure (10) according to one of the preceding claims, characterized in that the respective front and rear deformation elements (20, 22) and the buckling point (K) are coordinated with respect to their deformation properties in such a way that, in the event of an accident-related force being applied to the corresponding longitudinal member (12) in the direction of its longitudinal extension and if a defined limit force is exceeded, the front deformation element (20) first deforms in an energy-absorbing manner before the buckling point (K) is triggered and the rear deformation element (22) is activated.

10. Front structure (10) according to claim 9, characterized in that, in the event of continued accident-related force being applied to the front deformation element (20), the buckling point (K) is then triggered, while the rear deformation element (22) continues to withstand.

11. Front structure (10) according to claim 10, characterized in that, in the event of continued accident-related force application after the triggering of the buckling point (K), the rear deformation element (22) is finally deformed in an energy-absorbing manner.

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