Crashabsorptionseinrichtung

Abstract

Crash absorption device (4, 6, 7) for attachment to or integration into a module carrier (1) of a motor vehicle front end, wherein the crash absorption device (4, 6, 7) comprises at least one absorption body (4) which is designed such that it absorbs a force (F) acting on the absorption body (4) as a result of a crash and is deformed in the process, characterized in that the absorption body (4) has or consists of at least one foam material.

Description

[0001] The invention relates to a crash absorption device according to the preamble of claim 1.

[0002] Corresponding crash absorption devices are known from the prior art, for example from DE 10201500925 A1, DE 102015007121 A1, DE 102015014484 A1 or DE 102017010301 A1.

[0003] Such crash absorption devices are mounted on vehicle front ends and are designed to execute the most predictable deformation path possible in the event of a vehicle crash in order to absorb the forces introduced into the vehicle front end by the crash. Typically, the crash absorption devices designed for this purpose are made of plastic absorption bodies with a more or less complex structure of ribs and free spaces. The goal is always to achieve the most uniform force absorption possible across the deformation path. Fig. Figure 9 shows a schematic force-displacement diagram, where F denotes the force introduced into the absorption body by an external cause and s denotes the displacement, which are a measure of the deformation or compression of the absorption body. Ideally, an absolutely uniform force absorption over the deformation path (line L1) would be desirable. However, real absorption bodies often exhibit a displacement similar to line L2. Fig. 9, in which the force F becomes increasingly larger with increasing deformation path s, since the absorption body is compressed and thus compacted during the crash, so that an increasingly greater amount of force is required to achieve further compression.

[0004] Accordingly, it is desirable to provide a crash absorption device of the type mentioned above which can be manufactured in a simple and cost-effective manner and with which the most optimal force-displacement curve possible can be achieved for the absorption bodies used.

[0005] This object is achieved by a crash absorption device having the features of claim 1. Advantageous embodiments can be found in the subclaims.

[0006] The crash absorption device according to the invention is designed for attachment to or integration into a module carrier of a motor vehicle front end. It comprises at least one absorption body designed to absorb a force acting on the absorption body during a crash and is deformed in the process. The absorption body comprises or consists of at least one foam material.

[0007] Unlike previous plastic absorption bodies, which are usually manufactured using an expensive injection molding process, a foam barrier body can be produced comparatively inexpensively. Multiple foams can also be used together in production to create zones of varying compression hardness. Furthermore, foam is also very easy to mold, which significantly simplifies the manufacturing process. Furthermore, the compression behavior can be adjusted as desired by using different zones or foams of varying compression hardness. The external geometry, such as different cross-sections of the absorption body, can also be realized and adapted relatively easily thanks to the foam body design.

[0008] A preferred embodiment provides that the absorption body is formed from a plurality of regions.

[0009] At least two of the foam material areas have different compression hardnesses and / or foam materials. In this way, it can be achieved that a different deformation path is traveled in the initial phase of a crash than in a subsequent phase. By using different compression hardnesses and / or foam materials, it can be achieved that the force absorbed by the absorption body does not increase continuously over the deformation path, but rather a more constant force absorption is enabled compared to known solutions. It can be provided that the aforementioned areas are located one behind the other in the direction of travel or the opposite direction of travel, in which the main force component acts on the absorption body in the event of a crash.According to a preferred embodiment, the area first exposed to the force in the event of a crash can have the highest compressive strength, and the area furthest from this area can have the lowest compressive strength. This initially introduces a relatively high force into the deformation of the absorption body, and during the subsequent compression process, this force no longer increases significantly, so that the force-displacement curve is more uniform over the entire deformation path.

[0010] According to a further preferred embodiment, the cross-section of the absorption body increases, in particular continuously, from the area first exposed to the force in the event of a crash to the area furthest from this area. Such a tapering or widening of the absorption body in or against the direction of travel can alternatively or additionally achieve a similar effect as described above with different compression hardnesses and / or different foam materials.

[0011] While it is possible to connect the absorption body of the crash absorption device according to the invention directly to a structural component of a mounting support or the like, it is preferably provided that the crash absorption device according to the invention comprises a holder into which the absorption body is received. The absorption body can preferably be inserted, glued, and / or inserted in a form-fitting, material-fitting, and / or force-fitting manner. Other connection options not listed here are of course also conceivable as alternatives or supplements.

[0012] According to a particularly preferred embodiment, the holder comprises a plurality of side walls between which the absorption body is accommodated. In the simplest case, the absorption body can be inserted into the holder with a force fit.

[0013] Preferably, the mount includes an inner stabilizing element. This element is arranged in an interior space of the absorption body. This prevents or reduces lateral deflection of the absorption body in the event of a crash. A force component acting on the absorption body outside the direction of travel is then absorbed by the stabilizing element, so that the absorption body remains in position as much as possible and, ideally, is compressed exclusively in the direction of travel.

[0014] It is particularly preferred if the inner stabilizing element has telescopic sections arranged one behind the other in or against the direction of travel and secured to one another via predetermined breaking points. These telescopic sections then ensure that when force is applied parallel to the direction of travel, the individual telescopic sections can collapse into one another, thus preventing the compression of the absorption body.

[0015] According to a further embodiment of the present invention, it can be provided that an outer stabilizing element is arranged on the holder, in which the absorption body is arranged and which prevents or reduces lateral deflection of the absorption body in the event of a crash. While the inner stabilizing element ensures that the absorption body is prevented from deflecting from the inside, this can of course also be achieved alternatively or additionally by an outer stabilizing element. Of course, it must be ensured that the outer stabilizing element can also cause a desired deformation of the absorption body in the event of a crash. For this purpose, it can be provided that the outer stabilizing element has a cage-like shape with side walls and openings provided therein.Although this configuration offers sufficient protection against simple shearing or sideways breaking of the absorption body, it also ensures that the side walls are sufficiently flexible to be compressed with the absorption body when a force is applied parallel to the direction of travel.

[0016] The invention is described below with reference to Fig. 1 to 11 are explained in more detail. Fig. 1 shows a front view of a module carrier of a crash absorption device according to the invention. Fig. 2 shows a perspective view of a first embodiment of an absorption body of the crash absorption device according to the invention. Fig. 3 shows a crash absorption device according to the invention with the Fig. 2 shown absorption body. Fig. 4 shows a perspective view of an embodiment of a holder for an absorption body. Fig. 5 shows a plan view of the Fig. 4 shown bracket. Fig. 6 shows a side view of the Fig. 4 shown bracket. Fig. 7 shows a second embodiment of an absorption body according to the invention with a suitable holder in a perspective view. Fig. 8 shows the Fig. 7 shows the holder with absorption body in plan view. Fig. Figure 9 shows a schematic force-displacement diagram. Fig. 10 shows a perspective view of a module carrier with a further embodiment of a crash absorption device according to the invention. Fig. 11 shows a perspective view of a part of the Fig. 10 shown module carrier in an enlarged view.

[0017] Fig. Figure 1 schematically shows a module carrier 1 according to the invention at the front end of a vehicle. The carrier 2 has openings at the upper sections of the left and right ends, for example, for accommodating the headlight assembly, and is rigidly mounted to the vehicle chassis. The side carriers 3, on which the crash absorption elements 4 are arranged, are located at the lower left and right ends of the carrier 2. 5 denotes a crash management system.

[0018] Fig. 2 shows an embodiment of an absorption body 4 according to the invention. The basic shape of the absorption body 4 is almost cuboid or block-shaped, with the longest extent aligned in the direction of travel X of the vehicle. Almost means in this case that the front surface of the block-shaped absorption body 4 is smaller than that opposite the front surface; the cross-section increases continuously towards the rear. The absorption body 4 is preferably not made of a homogeneous material, but can comprise a foam material with two different compression hardnesses or different foams 41, 42 with different compression hardnesses. In this embodiment, viewed from the front side, the material with the lower compression hardness 42 is constructed in a lattice-like manner. In the example shown, it preferably forms a strut in the center in the vertical direction Z and has a plurality, e.g. five, cross struts, which e.g.in the horizontal direction Y. This pattern continues in the direction of travel X, with the wall thickness of the struts increasing. The gaps in the grid, which are formed by the material with the lower compression hardness 42, are filled by the material with the higher compression hardness 41. This foam 41 is again, for example, block-shaped, although in this case the area on the front side is slightly larger than that opposite the front side. In the event of a crash, the front part of the absorption body 4 absorbs greater forces during compression at the beginning of the collision because the proportion of material with the higher compression hardness 41 is relatively large. As the collision progresses, the force absorption remains almost constant because the proportion of material with the lower compression hardness 42 increases during further deformation. The deformation caused by the crash-induced force thus approaches the ideal shape L1 (see . Fig. 9).

[0019] Fig. 3 shows the absorption body 4 from Fig. 2 in the installed state. A bracket 6 is arranged on the module carrier 1 in the area of ​​the side support 3, which supports the absorption body 4. The arrangement 3, 4, 6 is designed such that the force F results in a substantially uniform deformation, which means that the force applied during an impact is distributed more evenly throughout the impact process and results in less of a somewhat flattened, punctiform peak.

[0020] The holder 6 for an absorption body 4 is inserted into the Fig. 4 to 6 in perspective form ( Fig. 4), in plan view ( Fig. 5) and in side view ( Fig. 6). The base 60 of the holder 6 is fixedly arranged on the side support 3. At the edges of the base 60, preferably perpendicular to the base, side walls 61 are arranged, which are connected to the base 60 as firmly as possible. Several ribs 611 are arranged on the outside of the side walls 61, which are supported on the side support 3 and thus give the side walls 61 greater stability. It is also possible to connect the side walls 61 to one another in order to reinforce their hold. The aim of these measures is to prevent possible transverse forces that are not parallel to the direction of travel X from shifting the structure into one another in the event of a force acting on the crash absorption device 4, 6. In order to stabilize the absorption body 4 against transverse forces, especially in the front area, a telescopic rod 62 is arranged centrally on the base 60.The telescopic rod 62 preferably comprises three cylindrical telescopic sections 621, 622, 623, which, viewed from the base 60, are arranged concentrically one above the other. They are supported by four ribs 624 arranged crosswise around the telescopic sections 621, 622, 623. The telescopic sections 621, 622, 623 are shaped such that the outer diameter of the upper telescopic section 621, 622 is smaller than the inner diameter of the telescopic section 622, 623 located below it, so that in the event of a collision, the telescopic sections can be pushed into one another when the absorption body 4 is compressed. When transverse forces occur, the telescopic rod 62 holds the absorption body 4 in position and gives way when forces occur in the direction of travel by pushing the telescopic sections 621, 622, 623 into each other.

[0021] The Fig. 7 and Fig. 8 show a further embodiment of a crash absorption device 4, 6 according to the invention in a perspective view ( Fig. 7) and in plan view ( Fig. 8). In this embodiment, the absorption body 4 is also constructed in a cuboid-like manner, whereby, as in the previous embodiment, the cross-section increases from front to rear towards the bracket 6. The difference from the previous embodiment is that the front side is beveled and that the cross-sectional enlargement 45a preferably becomes somewhat greater in the rear quarter. The internal structure is different; the cuboid-like absorption body 4 is divided into three regions 43, 44, 45 as seen in the direction of travel. Materials with different compressive strengths are used; preferably, the front region 43 is the region with the greater compressive strength, and the rear region 45 is the region with the lowest compressive strength. The beveled front side serves to replicate the curves of the vehicle and thus allow a relatively uncomplicated connection of the bumper elements 5. The thickened portion 45a in the rear quarter serves to improve fastening.

[0022] In this embodiment, the holder 6 comprises a base 60, with side walls 61 arranged on three edges, the sides and bottom. The side walls 61 are tapered inward on their inside so that they have approximately the same slope as the thickened portion 45a of the absorption body 4. This creates an undercut 61a in the side walls 61, which prevents the absorption body 4 from falling out toward the front. The holder 6 is open at the top, and the absorption body 4 can be inserted from above.

[0023] A force acting from the front on the crash absorption device 4, 6 will first compress the front region 43, which can absorb a high force per travel distance. Subsequently, the middle material 44 with the medium compression hardness is compressed, and finally, the region 45 with the lower compression hardness is added, so that a uniform force F is absorbed over the compression distance S and there is no force absorption peak.

[0024] In Fig. 10 and in a detail enlargement in Fig. 11 shows a further crash absorption device 4, 6, 7. In the module carrier 1, the side supports 3, on which the holder 6 is arranged, are located in the lower area at the left and right ends of the carrier 2. The absorption body 4 is accommodated in an outer stabilizing element 7 in this embodiment. The enlarged section shown in Fig. 11 shows the holder 6 arranged on the side support 3. With its side walls 61, the holder 6 clamps the side walls 71 of the outer stabilizing element 7. The side walls are provided with a plurality of openings 71a. If an absorption body 4 is used as in the first exemplary embodiment, this is inserted into the outer stabilizing element 7 and the assembly 4, 7 is arranged on the holder 6. In the event of a collision, the outer stabilizing element 7 absorbs the transverse forces. The forces coming from the front act not only on the absorption body 4, but also on the outer stabilizing element 7, whereby the openings 71a on the one hand facilitate compression of the outer stabilizing element 7 and, if necessary, on the other hand provide lateral escape space for the material of the absorption body 4.

[0025] The Fig.Figure 9 shows, as already discussed above, a force-displacement diagram F(s). The ideal force absorption during a crash would be continuous force absorption, as shown by the dashed line L1. In conventional systems, the force absorption is initially low because the absorption bodies can be easily compressed at first. The further the compression process progresses, the more force must be applied for further compression. This corresponds to the dotted / dashed line L2. Since the energy to be absorbed (force times displacement) corresponds to the area under the curve, the force absorption must become high towards the end of the collision in order to absorb the remaining impact energy. This can result in damage to the occupants and possibly to the cargo, despite the crash absorption device.The crash absorption device 4, 6, 7 according to the invention is designed to absorb a relatively large force per distance right at the beginning of the collision, as indicated by line L3. The high force absorption is maintained along the crash path, so that a high force absorption does not occur towards the end of the crash process, and the occupants and the load are better protected.

[0026] Due to the improved force absorption F per distance s, the crash absorption device 4, 6, 7 according to the invention makes a collision safer for the vehicle occupants and the load and thus contributes to improved road safety. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10201500925 A1

[0002] DE 102015007121 A1

[0002] DE 102015014484 A1

[0002] DE 102017010301 A1

[0002]

Claims

[1] Crash absorption device (4, 6, 7) for attachment to or integration into a module carrier (1) of a motor vehicle front end, wherein the crash absorption device (4, 6, 7) comprises at least one absorption body (4) which is designed such that it absorbs a force (F) acting on the absorption body (4) as a result of a crash and is deformed in the process, characterized by that the absorption body (4) comprises or consists of at least one foam material. [2] Crash absorption device (4, 6, 7) according to claim 1, characterized by that the absorption body (4) is formed from a plurality of regions (41, 42; 43, 44, 45), wherein at least two of the regions (41, 42; 43, 44, 45) comprise foam material with different compression hardnesses and / or foams. [3] Crash absorption device (4, 6, 7) according to claim 2, characterized bythat the areas (41, 42; 43, 44, 45) are located one behind the other in a direction of travel or in the opposite direction of travel in which the main force component acts on the absorption body in the event of a crash. [4] Crash absorption device (4, 6, 7) according to claim 2 or 3, characterized by that the area (43) first exposed to the force (F) in the event of a crash has the highest compression hardness and the area (45) furthest away from this area (43) has the lowest compression hardness. [5] Crash absorption device (4, 6, 7) according to one of claims 2 to 4, characterized by that the cross-section of the absorption body (4) increases, in particular continuously, from the area (43) first exposed to the force (F) in the event of a crash to the area (45) furthest away from this area (43). [6] Crash absorption device (4, 6, 7) according to one of the preceding claims, characterized bythat it comprises a holder (6) into which the absorption body (4) is received, preferably inserted, glued and / or inserted in a form-fitting, material-fitting and / or force-fitting manner. [7] Crash absorption device (4, 6, 7) according to claim 6, characterized by that the holder (6) comprises a plurality of side walls (61) between which the absorption body (4) is received. [8] Crash absorption device (4, 6, 7) according to claim 6 or 7, characterized by that the holder (6) comprises an inner stabilizing element (62) which is arranged in an interior of the absorption body (4) and which prevents or reduces lateral deflection of the absorption body (4) in the event of a crash. [9] Crash absorption device (4, 6, 7) according to claim 8, characterized bythat the inner stabilizing element (62) has telescopic sections (621, 622, 623) arranged one behind the other in or against the direction of travel (X) and fixed to one another via predetermined breaking points. [10] Crash absorption device (4, 6, 7) according to one of claims 6 to 9, characterized by that an outer stabilizing element (7) is arranged on the holder (6), in which the absorption body (4) is arranged and which prevents or reduces lateral deflection of the absorption body (4) in the event of a crash. [11] Crash absorption device (4, 6, 7) according to claim 10, characterized by that the outer stabilizing element (7) has a cage-like shape with side walls (71) and openings (71a) provided therein.

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