Crash-absorber structure for use in a motor vehicle

Abstract

The invention relates to a crash-absorber structure (2) for use in a motor vehicle, preferably for use in a side member of a motor vehicle, comprising a deformation body (4) for absorbing impact forces, which deformation body extends along a deformation axis (X), can be deformed along the deformation axis (X), has a length (L) and a material thickness (D) as well as a first and a second opening (6a, 6b) having a height (H) and a width (B), which openings are located at the end of the deformation body (4), wherein the deformation body (4) is in the form of a cast part made of a metal material and has a regular, undulating outer profile formed along the length (L) thereof.

Description

[0001] Description

[0002] Crash absorber structure for use in a motor vehicle

[0003] The present invention relates to a crash absorber structure for use in a motor vehicle and to a motor vehicle having such a crash absorber structure.

[0004] Crash absorber structures for use in motor vehicles are well known in the art. For reasons of weight and to maximize impact energy absorption, these crash absorber structures are typically made of joined metal sheets or extruded metal profiles.

[0005] Disadvantageously, sheet metal or extruded profile structures are less suitable with regard to maximum component integration to maximize a plurality of advantageous functions in a single component.

[0006] To solve this problem, crash absorber structures made of cast components are known from the prior art, for example from DE 198 58 303 B4, EP 1 759 958 B1, DE 10 2020205 196 B4 and DE 199 31 741 B4, which have a high level of component integration and combine a number of functions, such as a reduction in assembly costs and assembly time, space saving and weight reduction and the like.

[0007] Disadvantageously, the known crash absorber structures made of cast components have a lower ductility, which limits the absorption capacity for the impact energy.

[0008] It is therefore an object of the present invention to at least partially remedy the above-described disadvantages of a crash absorber structure for a motor vehicle.

[0009] In particular, it is the object of the present invention to provide a crash absorber structure for a motor vehicle which has a high level of component integration, is particularly structurally simple and can be produced cost-effectively and at the same time has a low weight and guarantees a high absorption capacity of impact energy.

[0010] The above object is achieved by the patent claims. Accordingly, the object is achieved by a crash absorber structure having the features of independent claim 1 and by a motor vehicle having the features of independent claim 11. Further features and details of the invention emerge from the subclaims, the description, and the drawings. Features and details described in connection with the crash absorber structure according to the invention naturally also apply in connection with the motor vehicle according to the invention, and vice versa, so that with regard to the disclosure of the individual aspects of the invention, reference is always made to each other.

[0011] According to the invention, a crash absorber structure is provided for use in a motor vehicle, preferably for use in a longitudinal member of a motor vehicle. The crash absorber structure according to the invention comprises a deformation body extending along a deformation axis and deformable along the deformation axis for absorbing impact forces, having a length and a material thickness, as well as first and second openings arranged at each end of the deformation body, each opening having a height and a width. The deformation body is designed as a cast component made of a metal material and has a regular, wave-shaped outer profile formed along its length.

[0012] According to the invention, the crash absorber structure, particularly through its design as a cast component with a wave-shaped outer profile formed along its length, is designed to enable a high capacity for absorbing impact forces and, at the same time, a high level of component integration for simple and cost-effective production as well as a low weight. The high capacity for absorbing impact forces is ensured in particular by the wave-shaped outer profile of the deformation body supporting the continuous generation of local bending modes. Thus, the wave-shaped outer profile according to the invention essentially provides a "pre-bend", which ensures that during deformation due to the absorption of impact forces, only moderate plastic strains occur in the bending zones and thus only locally limited cracks arise on the surfaces of the crash absorber structure subject to tensile load.The resulting folds hook and clamp into each other with further deformation and thus prevent the deformed areas from slipping, which ultimately leads to a progressive deformation behavior at a constant level.

[0013] The crash absorber structure according to the invention can preferably be arranged in the front and / or rear region, in particular in a longitudinal member of a motor vehicle. It is understood that the crash absorber structure according to the invention can be used not only in motor vehicles, such as passenger cars or trucks, but also in commercial vehicles or the like. Within the scope of the invention, a deformation axis can preferably be understood as an axis along which the crash absorber structure in question deforms most easily or preferentially under load. Within the scope of the invention, a deformation body can be understood in particular as a body that deforms under load, in particular due to external impact forces, while absorbing the impact energy.Within the scope of the invention, a regular, wave-shaped outer profile can be understood in particular as an outer wave-shaped profile with a uniform amplitude and wavelength, which is preferably arranged symmetrically around a center line. Corresponding to the uniform design and symmetrical arrangement, the deformation body in question is preferably divided along its length and along the deformation axis into a series of identically designed deformation chambers. With a view to particularly high deformability along a deformation axis and with a view to simple and cost-effective production of a crash absorber structure, the invention can advantageously provide for the deformation body to also have a regular, wave-shaped inner profile formed along its length.With regard to a casting-friendly design of the crash absorber structure in question, the shape of the inner and outer profile can be of the same design and the crash absorber structure can preferably have constant wall thicknesses.

[0014] With a view to weight optimization and the most complete possible component integration, the invention advantageously provides for the deformation body to be made of an aluminum material, preferably a die-cast aluminum alloy. With the aid of the crash absorber structure according to the invention, it is possible to generate a structure that enables very efficient and robust absorption of impact energy, despite the comparatively low ductility of die-cast aluminum alloys.

[0015] As part of an improved fastening of the crash absorber structure in question and an improved force transmission along a deformation axis, the invention can advantageously further provide for the deformation body to have a first and second end piece arranged at the end with a rectilinear outer profile. The first and second end pieces can advantageously be designed in the form of a flange, each of which preferably comprises a plurality of recesses for inserting fastening means, such as screws or the like, and can thus be easily and quickly fastened, for example, to a longitudinal member of a motor vehicle.

[0016] In order to ensure a high absorption capacity of impact forces along a deformation axis and at the same time the highest possible component integration, it can advantageously be provided that the deformation body is hollow-shaped, wherein preferably the first and second opening are circular, wherein the deformation body in particular has a hollow-cylindrical basic structure.

[0017] With a view to a simple, rapid and material-saving design of a crash absorber structure according to the invention, it can advantageously be provided that the deformation body is trough-shaped, wherein preferably the first and second opening are semicircular, wherein the deformation body in particular has a semi-hollow cylindrical basic structure.

[0018] With regard to a flexible adaptation to an available installation space, it can also be advantageously provided that the deformation body is trough-shaped, wherein preferably the first and second opening are U-shaped, wherein the height of the first and second opening is preferably greater than the width of the first and second opening.

[0019] To achieve stabilization of the deformation body along axes other than the deformation axis, it can further be provided that stabilizing webs are provided perpendicular to the deformation axis to stabilize the deformation body, wherein the stabilizing webs are preferably arranged parallel to the first and second openings. The stabilizing webs are preferably integrated into the cast component in a demoldable manner.

[0020] Within the scope of a robust and stable design of a crash absorber structure with a high absorption capacity of impact forces along a deformation axis, it can further be provided according to the invention that the deformation body is formed in one piece.

[0021] For the simple and rapid production of a robust and stable crash absorber structure with a high capacity to absorb impact forces along a deformation axis, it is further conceivable for the deformation body to be constructed in multiple parts, wherein the deformation body is preferably composed of an upper and an identically constructed lower element. The upper and lower elements are each, in particular, semi-hollow cylindrical and are combined to form a hollow cylindrical deformation body. The upper and lower elements can preferably be joined chemically, mechanically, or thermally, in particular by being glued, riveted, or welded to one another.

[0022] As a further embodiment for a wave-shaped outer profile of a crash absorber structure with a high capacity to absorb impact forces along a deformation axis, it can also advantageously be provided that the regular wave-shaped outer profile is helical in shape. The demolding of the core and outer contour can preferably be carried out via axial de-spindling in a die-casting tool.

[0023] The invention furthermore relates to a motor vehicle comprising at least one, preferably at least two, crash absorber structures described above. Thus, the motor vehicle according to the invention offers the same advantages as those already described in detail with regard to the crash absorber structure according to the invention.

[0024] Further advantages, features, and details of the invention will become apparent from the following description, which describes exemplary embodiments of the invention in detail with reference to the drawings. The features mentioned in the claims and in the description may be essential to the invention individually or in any combination.

[0025] They show schematically:

[0026] Figure 1 shows a crash absorber structure according to the invention in a spatial view according to a first embodiment,

[0027] Figure 2 shows a crash absorber structure according to the invention in a spatial view according to a second embodiment,

[0028] Figure 3 shows a crash absorber structure according to the invention in a spatial view according to a third embodiment,

[0029] Figure 4 shows a crash absorber structure according to the invention in a spatial view according to a fourth embodiment,

[0030] Figure 5 shows a crash absorber structure according to the invention in a spatial view according to a fifth embodiment,

[0031] Figure 6 shows a crash absorber structure according to the invention in a spatial view according to a sixth exemplary embodiment, Figure 7 shows an illustration of the energy-absorbing deformation mechanism of the crash absorber structure according to the invention in the event of an impact.

[0032] Figure 1 shows a crash absorber structure 2 according to the invention in a spatial view according to a first embodiment.

[0033] As can be seen from Figure 1, the crash absorber structure 2 comprises a deformation body 4 which extends along a deformation axis X and is deformable along the deformation axis X for absorbing impact forces, with a length L and a material thickness D, a first and second opening 6a, 6b arranged at each end of the deformation body 4 with a height H and a width B, wherein the deformation body 4 is designed as a cast component made of a metal material and has a regular wave-shaped outer profile formed along its length L.

[0034] The deformation body 4 can advantageously be made of an aluminum material, in particular of an aluminum die-cast alloy.

[0035] As can be seen from Figure 1, the deformation body 4 with the material thickness D is formed in one piece and comprises a first end piece 8a arranged at the end with a rectilinearly shaped outer profile.

[0036] It can also be seen that the deformation body 4 is hollow and the first and second openings 6a, 6b are circular, so that the deformation body 4 in the present case has an at least approximately hollow-cylindrical basic structure.

[0037] Figure 2 shows a crash absorber structure 2 according to the invention with an at least approximately hollow cylindrical basic structure in a spatial view according to a second exemplary embodiment, in which the regular wave-shaped outer profile is helical.

[0038] Figure 3 shows a crash absorber structure 2 according to the invention with an at least approximately hollow cylindrical base structure in a spatial view according to a third exemplary embodiment, in which the deformation body 4 is designed in several parts and is composed of an upper and an identically designed lower element 10a, 10b, wherein the upper and lower elements 10a, 10b are each designed as a semi-hollow cylinder and are combined to form a hollow cylindrical deformation body 4. Figure 4 shows a crash absorber structure 2 according to the invention with an at least approximately semi-hollow cylindrical base structure in a spatial view according to a fourth exemplary embodiment, in which the deformation body 4 is designed as a trough, wherein preferably the first and second openings 6a, 6b are designed as semicircular and the deformation body 4 has a semi-hollow cylindrical base structure.

[0039] Figure 5 shows a crash absorber structure 2 according to the invention in a spatial view according to a fifth exemplary embodiment, in which the deformation body 4 is also trough-shaped, but the first and second openings 6a, 6b are U-shaped, wherein the height H of the first and second openings 6a, 6b is preferably greater than the width B of the first and second openings 6a, 6b.

[0040] Figure 6 shows a crash absorber structure 2 according to the invention in a spatial view according to a sixth exemplary embodiment, which is constructed in the same way as the crash absorber structure 2 according to the invention according to the fifth exemplary embodiment, except that here additional stabilizing webs 12 are provided for stabilizing the deformation body 4 perpendicular to the deformation axis X, which are arranged parallel to the first and second openings 6a, 6b. It is understood that the wave-shaped end pieces 8a shown in Figures 5 and 6 can also be planar.

[0041] Figure 7 shows a representation of the energy-absorbing deformation mechanism of the crash absorber structure 2 according to the invention during an impact.

[0042] As can be seen in the sequence of images a to h, the high impact energy absorption capacity of the crash absorber structure 2 according to the invention is ensured in particular by the fact that the wave-shaped outer profile of the deformation body 4 supports the continuous generation of local bending modes. Thus, the wave-shaped outer profile according to the invention essentially provides a "pre-bend," which ensures that during deformation due to the absorption of impact forces, only moderate plastic strains occur in the bending zones and thus only locally limited cracks develop on the surfaces of the crash absorber structure 2 subjected to tensile load.As can also be seen in the sequence of images a to h, the resulting folds interlock and clamp with further deformation, thus preventing the deformed areas from slipping, which ultimately leads to a progressively increasing deformation behavior at a constant level, as can be seen from the plot of force versus deformation path shown below. The above explanation of the embodiments describes the present invention exclusively by way of examples. Of course, individual features of the embodiments can be freely combined with one another, provided they are technically feasible, without departing from the scope of the present invention.

[0043] List of reference symbols

[0044] 2 Crash absorber structure

[0045] 4 deformation bodies

[0046] 6a first opening

[0047] 6b second opening

[0048] 8a first end piece

[0049] 8b second end piece

[0050] 10a upper element

[0051] 10b lower element

[0052] 12 Stabilization bar

[0053] X deformation axis

[0054] L length

[0055] D Material thickness

[0056] H Height

[0057] B Width

Claims

Patent claims 1. Crash absorber structure (2) for use in a motor vehicle, preferably for use in a longitudinal member of a motor vehicle, comprising: a deformation body (4) extending along a deformation axis (X) and deformable along the deformation axis (X) for absorbing impact forces, with a length (L) and a material thickness (D), a first and second opening (6a, 6b) arranged at each end on the deformation body (4) with a height (H) and a width (B), characterized in that the deformation body (4) is designed as a cast component made of a Meta II material and has a regular wave-shaped outer profile formed along its length (L).

2. Crash absorber structure (2) according to claim 1, characterized in that the deformation body (4) is formed from an aluminum material, preferably from an aluminum die-cast alloy.

3. Crash absorber structure (2) according to claim 1 or 2, characterized in that the deformation body (4) has a first and second end piece (8a, 8b) arranged at the end with a rectilinearly shaped outer profile, wherein the first and second end piece (8a, 8b) arranged at the end preferably have a greater material thickness (D) than the remaining part of the deformation body (4).

4. Crash absorber structure (2) according to one of the preceding claims, characterized in that the deformation body (4) is hollow-shaped, wherein preferably the first and second openings (6a, 6b) are circular, wherein the deformation body (4) in particular has a hollow-cylindrical basic structure.

5. Crash absorber structure (2) according to one of the preceding claims, characterized in that the deformation body (4) is trough-shaped, wherein preferably the first and second openings (6a, 6b) are semicircular, wherein the deformation body (4) in particular has a semi-hollow cylindrical basic structure.

6. Crash absorber structure (2) according to one of the preceding claims, characterized in that the deformation body (4) is trough-shaped, wherein preferably the first and second openings (6a, 6b) are U-shaped, wherein the height (H) of the first and second openings (6a, 6b) is preferably greater than the width (B) of the first and second openings (6a, 6b).

7. Crash absorber structure (2) according to one of the preceding claims, characterized in that stabilizing webs (12) are provided for stabilizing the deformation body (4) perpendicular to the deformation axis (X), wherein the stabilizing webs (12) are preferably arranged parallel to the first and second openings (6a, 6b).

8. Crash absorber structure (2) according to one of the preceding claims, characterized in that the deformation body (4) is formed in one piece.

9. Crash absorber structure (2) according to one of the preceding claims, characterized in that the deformation body (4) is designed in several parts, wherein the deformation body (4) is preferably composed of an upper and an identically designed lower element (10a, 10b), wherein the upper and the lower element (10a, 10b) are each designed in particular in the shape of a semi-hollow cylinder and are combined to form a hollow cylindrical deformation body (4).

10. Crash absorber structure (2) according to one of the preceding claims, characterized in that the regular wave-shaped outer profile is helical.

1. Motor vehicle, comprising at least one crash absorber structure (2) according to one of claims 1 to 10, preferably two crash absorber structures (2) according to one of claims 1 to 10.

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