Crash box for a crash management system, as well as a crash management system with such a crash box

Abstract

The crash box (1) for a crash management system (10) comprises a base body (2) extending in a longitudinal direction (X) and being at least partially tubular. The base body (2) has an end section (E1) designed for connection to a cross member (11) and an end section (E2) opposite the end section (E1) designed for screw connection to a vehicle structure (100). The end section (E2) comprises individual connecting elements (M1 - M4). The end section (E2) has a laterally open, in particular U-shaped, cross-section, which has two legs (E2a, E2b) and a web (E2c) connecting the legs (E2a, E2b) to each other. At least one, preferably two, of the connecting elements (M2, M3) is / are arranged on the web (E2c).

Description

[0001] The invention relates to a crash box for a crash management system according to the features in the preamble of claim 1 and to a crash management system with the features of claim 6. Furthermore, the invention relates to the use of such a crash box or such a crash management system according to the features of claim 10.

[0002] Motor vehicles in road traffic are subject to stringent requirements regarding the protection of occupants and other road users. In addition to restraint systems and airbags, the safety technology employed includes so-called crash management systems (CMS). Their primary function is to minimize the impacts and effects of an accident on all persons involved. CMS are therefore designed to deform in a crash in order to absorb the impact energy as much as possible. This also benefits the rest of the vehicle structure, as it remains largely intact in a crash, especially at low speeds. Beyond personal protection, a CMS can thus also contribute to reducing accident-related repair costs.

[0003] Motor vehicles are manufactured modularly, with entire assemblies only being joined together during final assembly. A pre-assembled front-end module (FEM) can already include all essential components, ranging from headlights and bumper cover with the shock absorber behind it to cooling components and any sensors. Increasingly, the respective crash management system (CMS) is also being integrated into the FEM. A CMS typically includes at least one crossmember and two crash boxes, which connect the crossmember to the vehicle's longitudinal members. The crossmember, which was visible as the bumper in early motor vehicles, is now concealed behind the FEM's bumper cover, which now defines the vehicle's front appearance.

[0004] German patent DE 10 2008 045 515 A1 discloses a crash management system (CMS) that has a cross member which can be connected to the longitudinal members of a vehicle via two crash boxes. Each crash box comprises a longitudinally extending, tubular base body. The base body has both an end section designed for connection to the cross member and an end section opposite this end section, which is designed for bolted connection to the vehicle structure. For this purpose, the end section of each crash box has a circumferential flange with bolt holes. To attach the CMS, fasteners, essentially parallel to the longitudinal direction of the vehicle, are inserted through the bolt holes of the crash boxes and bolted to the longitudinal members.

[0005] When integrating the CMS into an FEM, frontal access to the screw holes is largely prevented, especially by the bumper cover, making the connection of the CMS to the longitudinal members of the vehicle at least more difficult.

[0006] WO 2019 / 120840 A1 discloses a CMS in which the end sections of the respective tubular base bodies of the two crash boxes are designed to be inserted into corresponding receptacles in a vehicle structure. Without end flanges, the two opposing side walls of each crash box each have two threaded connecting elements, in particular nuts with internal threads, the respective threads forming an angle between themselves and the longitudinal direction of the base body of the respective crash box. In this way, each side wall of a crash box can be connected to the corresponding receptacle on the vehicle structure by means of two screws, which are inserted through a screw hole in the receptacle into the connecting elements of the crash boxes, where the external threads of the connecting elements engage with the threads of the connecting elements.

[0007] The laterally oriented connecting elements of the crash boxes allow the connecting screws to be positioned from both the wheel wells and the engine compartment. This provides access to the connecting elements, which would otherwise be difficult or even impossible when integrating the CMS into an FEM. However, the pluggable design of the crash boxes requires a high degree of dimensional accuracy in the parts that come into contact with each other. Even minor tolerances in the external geometry of the end sections of the crash boxes and / or in the internal geometry of the mountings on the vehicle structure can complicate or even prevent their mating. The same applies to the respective distances between the crash boxes and the mountings, which are necessary to insert the end sections of the two crash boxes into the mountings.The arrangement of the screw holes on the mounts and the connecting elements on the two side walls of each crash box also allows only very small tolerances in order to align them with each other.

[0008] The present invention is therefore based on the objective of further developing a crash box and a crash management system equipped with it in such a way that they enable a simpler and less sensitive method of connection to a vehicle structure, in particular made of die-casting, preferably aluminum die-casting.

[0009] The problem is solved by a crash box with the features of claim 1 and a crash management system according to the features of claim 7. Advantageous further developments are the subject of the respective dependent claims.

[0010] According to the invention, the crash box comprises a longitudinally extending and at least partially tubular base body, which has an end section provided for connection to a cross member and an end section opposite the end section, designed for screwable connection to a vehicle structure, which has individual connecting elements. Preferably, these connecting elements each have a thread extending in a transverse direction and forming an angle between themselves and the longitudinal direction of the base body. According to the invention, the end section has a laterally open, in particular U-shaped, cross-section. In this embodiment, the laterally open end section has two legs and a web connecting the legs. At least one of the connecting elements, preferably two of the connecting elements, is / are arranged on the web.

[0011] The resulting advantage lies primarily in the fact that the crash box according to the invention requires only a lateral access point to connect it to a vehicle structure, in particular the longitudinal member of a vehicle. The laterally open cross-section of its end section results in a single-shear connection, which allows for significantly higher tolerances. This is mainly because previously known crash boxes require high dimensional accuracy in the shape, especially the height and width, of their otherwise completely closed end section to enable insertion into the corresponding receptacle on a vehicle structure. The same requirement also applies to the receptacle itself. Excessive tolerances can prevent the end section from being inserted into the receptacle or cause it to have excessive play within it.

[0012] The two-section connection inherent in the previously known crash boxes with lateral connections further increases the requirements for dimensional accuracy. The connecting elements – in the form of nuts – located on both side walls must be aligned with corresponding screw holes in the respective mounting brackets to allow the four screws necessary for securing the box to be inserted through the respective screw holes and connected to the corresponding connecting element. Even reducing the number of connecting elements to just two and placing them on only one side wall of the end section necessitates the insertion of additional spacers into its cross-section to prevent deformation of the crash box when tightening the screws and / or to ensure sufficient tension in the screw connection.

[0013] Since the crash box according to the invention does not require such insertion of its end section, but only the lateral attachment of its laterally open cross-section to the vehicle structure, far fewer tolerances need to be considered in its manufacture. Particularly with regard to the arrangement of usually at least two crash boxes on a cross member, the spacing between the crash boxes is essentially the only factor to consider in the solution according to the invention, so that they fit between the areas of the vehicle structure intended for lateral attachment. A certain amount of play between the crash boxes and the vehicle structure can even be intentional and easily compensated for, since the respective side wall of the end section of the crash box can be drawn towards the vehicle structure when screwed in place, due to its single-walled design – which is more elastic because of the laterally open cross-section.

[0014] In a particularly preferred embodiment of the basic inventive concept, an arm can be arranged on each of the two legs of the end section. The arms are preferably arranged at the ends of their respective legs. In any case, the arms extend away from each other, with at least one of the connecting elements being arranged on each arm. The arms provide additional components for the arrangement of the connecting elements, which are also easily accessible. Furthermore, the arms increase the dimensions of the end section, thereby, for example, giving it a higher moment of resistance to lateral deflection and / or allowing the crash box's behavior upon impact to be advantageously adjusted.

[0015] With regard to the end section, the invention provides that its web and arms each have an inner surface intended for at least partial contact with a part of a vehicle structure, wherein the connecting elements can be arranged on the respective inner surfaces of the outer surfaces of the arms and the web facing away from the vehicle structure. In other words, the connecting elements can thus be located on the outer surface of the web and the two arms facing away from the vehicle structure during intended use. This allows for the most extensive possible contact between the web and the two arms and the areas of the vehicle structure intended for connection, in order to reliably transmit the forces occurring during connection and in the event of a crash between the CMS and the vehicle structure.

[0016] The invention provides that the base body of the crash box can comprise two housing shells. Preferably, each of these housing shells can have a C-shaped cross-section, at least partially. Advantageously, each housing shell can have two half-walls and a side wall connecting the half-walls. Each half-wall of one housing shell is then connected to a half-wall of the other housing shell, forming a hollow body. This design enables cost-effective manufacturing of the crash box.

[0017] Alternatively, their base body can of course also be formed by a section of a correspondingly shaped hollow body, which itself receives its respective shape, for example, by hydroforming or extrusion.

[0018] In a particularly advantageous manner, the half-walls and the side wall of a housing shell, preferably of both housing shells, can form a single, integral component made of the same material. This allows at least one housing shell to be manufactured, for example, from a semi-finished product by forming it. In any case, the end section of the base body is a single, integral component made of the same material in one of the two housing shells.

[0019] The crash box according to the invention, as presented here, offers an extremely simple and tolerance-insensitive method of connection to a vehicle structure. In contrast, with previously known, closed crash boxes, both the dimensions relating to the spacing between the crash boxes and their respective shapes are subject to much tighter tolerances in order for these crash boxes to fit into the corresponding components on the vehicle structure. The laterally open design of the cross-section of the crash box according to the invention contributes significantly to this.Because of the connecting elements arranged on both side walls of the previously known crash boxes with pluggable end sections, these must be screwed together from two sides. In contrast, arranging these connecting elements on only one side wall of the completely closed cross-section requires the insertion of spacers to prevent deformation of the crash box when tightening the screws and / or to ensure sufficient tension in the screw connection. For the embodiment according to the invention, maintaining the tolerance between the two crash boxes is essential, as they do not need to be plugged in anywhere and must be aligned with a complex hole pattern.Any play between the crash boxes and the vehicle structure is even intentional and easily compensated for, since the respective side wall of the end section of the crash box is used when screwing it to the vehicle structure due to its elastic single-walled design.

[0020] The invention is further directed to a crash management system for a vehicle, in particular a motor vehicle, which comprises two crash boxes according to the invention as described above, as well as at least one cross member. The resulting advantage has already been explained in more detail in connection with the crash box according to the invention, so that, to avoid repetition, reference is made here to the corresponding explanations.

[0021] In a preferred embodiment of the crash management system according to the invention, a plate element can be provided in the end section of each crash box. Preferably, each of these plate elements can be oriented transversely to the longitudinal direction of the two crash boxes. In any case, the plate elements can each have two slot-shaped recesses, each of which at least partially encompasses one of the two half-walls of a housing shell. The respective plate element can advantageously serve to reinforce the cross-section of the associated crash box. The respective plate element can serve to support the associated crash box against the vehicle structure with respect to its longitudinal direction in order to reliably transmit the forces occurring during an impact. Alternatively or additionally, the respective plate element can, of course, also serve as a support for further components.

[0022] Depending on the design, the base body of each crash box can be completely open along its longitudinal direction. According to an advantageous embodiment, each plate element can have a wall section located between its two slot-shaped recesses, by which the base body of the associated crash box is at least partially closed in the area of ​​its connecting section.

[0023] Alternatively or additionally, each plate element can have a cantilever, preferably made of a single piece of material, at the free end of which a mounting area is located. These cantilevers can serve to connect a secondary beam, in particular one extending parallel to the crossbeam, to the mounting areas of the two cantilevers, incorporating a crash element in each case.

[0024] Ultimately, the invention is directed towards the use of a crash box or crash management system according to the invention, as described above, for a vehicle structure made of die-cast aluminum. Preferably, the vehicle structure can be made of die-cast aluminum.

[0025] The invention is explained in more detail below with reference to an exemplary embodiment schematically illustrated in the individual figures. The figures show: Fig. 1 a crash box according to the invention in a perspective view, Fig. 2 the crash box out Fig. 1 in an exploded view in an otherwise unchanged perspective view, Fig. 3 a crash management system according to the invention comprising Fig. 2 Crashbox shown as an exploded view in combination with other components, Fig. 4 a part of the crash management system Fig. 3 in a wider perspective view, Fig. 5 the crash management system Fig. 3 in a perspective view rotated 180° horizontally and Fig. 6 a part of the crash management system Fig. 5 in a further rotated perspective view together with part of a vehicle structure.

[0026] Fig. Figure 1 shows a crashbox 1 according to the invention in a perspective view. The crashbox 1 comprises a base body 2 extending in a longitudinal direction X. The base body 2 has an end region E1 and an end section E2 opposite the end region E1. The end region E1 serves to connect the crashbox 1 to a component not shown in detail here and only in the Fig. 3, Fig. 5 and Fig. 7 section-by-section crossbeam 11. In contrast, the end section E2 is provided for the screwable connection of the crash box 1 to a vehicle structure 100, which is only in the Fig. 6 and Fig. 7 is indicated.

[0027] Fig. 2 shows the crash box 1 from Fig. 1 in an exploded view. This makes it clear that the base body 2 comprises two housing shells 3, 4. Each housing shell 3, 4 has two half-walls 3a, 3b; 4a, 4b and a side wall 3c, 4c connecting its half-walls 3a, 3b; 4a, 4b. Specifically, the one with reference to the representation in Fig. 2 left housing shell 3 the two half-walls 3a, 3b and the side wall 3c connecting them, while the with reference to the illustration in Fig. The right housing shell 4 comprises the two half-walls 4a, 4b and the side wall 4c connecting them. This allows the two housing shells 3, 4 to be described as C-shaped in cross-section, at least in sections. Preferably, the half-walls 3a, 3b; 4a, 4b and the side wall 3c, 4c of each housing shell 3, 4 can form a single, integral component made of the same material, as can be seen here by way of example. Advantageously, the end section E2 can form a single, integral component made of one of the two housing shells 3, 4. As can be seen, the end section E2 is shown here, purely by way of example, as a single, integral component made of the same material, as illustrated in Fig. 2. Left housing shell 3. Each half-wall 3a, 3b; 4a, 4b of one housing shell 3, 4 is connected to a half-wall 3a, 3b; 4a, 4b of the other housing shell 3, 4, forming a hollow body. Specifically, in the example shown, the two half-walls 3a, 4a and the two half-walls 3b, 4b are connected to each other at their facing edges, as shown in particular in Fig. 1 evident and in Fig. 2 indicated. Further recognizable, the end section E2 has a laterally open, essentially U-shaped, cross-section, which has two legs E2a, E2b and a web E2c connecting the legs E2a, E2b.

[0028] An arm A1, A2 is arranged at the end of each of the two legs E2a, E2b of the end section E2. Specifically, arm A1 is located on leg E2a, while arm A2 is located on leg E2b. The two arms A1, A2 clearly extend away from each other. Both the bridge E2c and the two arms A1, A2 each exhibit at least partial contact with a part of the [unclear text]. Fig. 6 and Fig. 7 indicated vehicle structure 100 planned interior surfaces IF1 - IF3.

[0029] Fig. Figure 3 shows a crash management system 10 according to the invention for a vehicle not shown here, which comprises two of the crash boxes 1 according to the invention as described above and a cross member 11. For better clarity, only one crash box 1 is shown here, while only an end section of the cross member 11 is visible. Further details regarding the in Fig. The provisions of the three visible crashboxes 1 apply analogously to the further crashbox 1 not shown here. As can be seen, a plate element 5, oriented essentially transversely to the longitudinal direction X, is provided in the area of ​​the end section E2 of the crashbox 1 – in particular, of each crashbox 1. The plate elements 5 – of which only one is shown here – each have two slot-shaped recesses 5a, 5b, which, in the assembled state of the crash management system 10, each form one of the two half-walls E2a, E2b of the – with reference to the illustration in Fig. 3 left - housing shell 3 at least partially encompass. Each plate element 5 has a wall section 5c located between its two slot-shaped recesses 5a, 5b, through which the base body 2 of the associated crash box 1, which is continuously open with respect to the longitudinal direction X, is at least partially closed in the area of ​​its connecting section E2 in the assembled state of the crash management system 10.

[0030] Fig. Figure 4 illustrates the design of the crash box 1 together with the plate element 5 in the assembled state of the crash management system 10, whose cross member 11 is not visible here for the sake of clarity.

[0031] Fig. Figure 5 shows a perspective view of the crash management system 10 in a further rotated representation. The end section E2 clearly has several connecting elements M1–M4, each of which can be threaded elements G1–G4, such as nuts or the like. In the embodiment shown here, the two connecting elements M2 and M3 are arranged on the web E2c of the end section E2, while two further connecting elements M1 and M4 are each arranged on one of the two arms A1 and A2. The individual connecting elements M1–M4 are arranged on the outer surfaces AF1–AF3 of the arms A1 and A2 and the web E2c, opposite the respective inner surfaces IF1–IF3.

[0032] Fig. Figure 6 shows a part of the crash management system 10 according to the invention and a part of a vehicle structure 100 to which the crash management system 10 is to be connected. The vehicle structure 100 is preferably made, at least in part, of die-cast material, preferably aluminum die-cast. The vehicle structure 100 itself has individual through-holes or screw holes through which screws, also indicated here, can be arranged to engage with the threads G1-G4, preferably internal threads, of the respective crash box 1. The area of ​​the vehicle structure 100 intended for connection with the respective crash box 1 of the crash management system 10 is adapted to the design of the crash box 1.Preferably, the threads G1 - G4 are each arranged in one of the connecting elements M1, M4, each extending in a transverse direction Y1 - Y4 and being able to enclose an angle W between themselves and the longitudinal direction X of the base body 2.

[0033] Fig. Figure 7 shows another part of the crash management system 10 together with a part of the vehicle structure 100. It is evident that each plate element 5 has a cantilever 5d, preferably made of a single piece of material, at the free end of which a fastening area 5e is located (see also Figure 7). Fig. 3 and Fig. 4) Furthermore, a secondary support 12 extending preferably parallel to the crossbeam 11 is provided, which is connected, in particular, to the respective fastening area 5e of the associated boom 5 by incorporating a crash element 13. Reference symbol list: 1 Crashbox 2 basic bodies of 1 3 housing shells of 2 3a Half wall of 3 3b Half wall of 3 4 housing shells of 2 4a Half wall of 4 4b Half wall of 4 5 plate elements out of 10 5a Exclusion of 5 5b Exclusion of 5 5c Wall section of 5 5d boom of 5 5e Mounting area of ​​5 10 Crash Management System 11 crossbeams out of 10 12 secondary beams out of 10 13 crash elements out of 10 100 Vehicle structure A1 Arm to E2a A2 arm to E2b AF1 Outer surface of A1 AF2 Outer surface of A2 AF3 Outer surface of E2c E1 End range of 2 E2 End section of 2 E2a leg of E2 E2b leg of E2 E2c Bridge from E2 G1 thread from M1 G2 thread from M2 G3 thread from M3 G4 thread from M4 IF1 Inner surface of A1 IF2 Inner surface of A2 IF3 inner surface of E2c M1 connecting element at A1 M2 connecting element at E2c M3 connecting element at E2c M4 connector at A2 W angle X Longitudinal direction of 2 Y1 transverse direction of G1 Y2 transverse direction of G2 Y3 transverse direction of G3 Y4 transverse direction of G4 QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2008 045 515 A1

[0004] WO 2019 / 120840 A1

[0006]

Claims

[1] Crashbox (1) for a crash management system (10), comprising a longitudinally extending (X) and at least partially tubular base body (2), which has an end section (E1) provided for connection with a cross member (11) and an end section (E2) opposite the end section (E1) designed for screwable connection to a vehicle structure (100), wherein the end section (E2) comprises individual connecting elements (M1 - M4), characterized by , that the end section (E2) has a laterally open, in particular U-shaped, cross-section which has two legs (E2a, E2b) and a web (E2c) connecting the legs (E2a, E2b) together, wherein at least one, preferably two, of the connecting elements (M2, M3) is / are arranged on the web (E2c). [2] Crashbox (1) according to claim 1, characterized by, that the connecting elements (M1 - M4) each have a thread (G1 - G4) extending in a transverse direction (Y1 - Y4) and enclosing an angle (W) between themselves and the longitudinal direction (X) of the base body (2), in particular an internal thread. [3] Crashbox (1) according to claim 1 or 2, characterized by , that an arm (A1, A2) is arranged on each of the legs (E2a, E2b), in particular at the ends, wherein the arms (A1, A2) extend away from each other, wherein at least one of the connecting elements (M1, M4) is arranged on each of the arms (A1, A2). [4] Crashbox (1) according to claim 1, 2 or 3, characterized by, that the web (E2c) and the arms (A1, A2) each have an inner surface (IF1 - IF3) intended for at least partial contact with a part of a vehicle structure (100), wherein the connecting elements (M1 - M4) are arranged on the outer surfaces (AF1 - AF3) of the arms (A1, A2) and the web (E2c) facing away from the respective inner surfaces (IF1 - IF3). [5] Crashbox (1) according to any one of the preceding claims, characterized by , that the basic body (2) comprises two, in particular at least partially C-shaped in cross-section, housing shells (3, 4), each of which has two half-walls (3a, 3b; 4a, 4b) and a side wall (3c, 4c) connecting the half-walls (3a, 3b; 4a, 4b) together, wherein each half-wall (3a, 3b; 4a, 4b) of a housing shell (3, 4) is connected to a half-wall (3a, 3b; 4a, 4b) of the other housing shell (3, 4) to form a hollow body. [6] Crashbox (1) according to claim 4, characterized by, that the half-walls (3a, 3b; 4a, 4b) and the side wall (3c, 4c) of a housing shell (3, 4) are integral parts of the same material, wherein the end section (E2) is integral parts of one of the two housing shells (3, 4). [7] Crash management system (10) for a vehicle, comprising at least one cross member (11) and two crash boxes (1) according to one of the preceding claims. [8] Crash management system (10) according to claim 7, characterized by , that in the area of ​​the end section (E2) of each crashbox (1) a plate element (5) is provided, in particular oriented transversely to the longitudinal direction (X), wherein the plate elements (5) each have two slot-shaped recesses (5a, 5b) which each at least partially encompass one of the two half-walls (E2a, E2b) of a housing shell (3). [9] Crash management system (10) according to claim 8, characterized by, that each plate element (5) has a wall section (5c) located between its two slot-shaped recesses (5a, 5b) by which the base body (2) of the associated crash box (1), which is open throughout, in particular with respect to the longitudinal direction (X), is at least partially closed in the area of ​​its connecting section (E2). [10] Crash management system (10) according to claim 8 or 9, characterized by , that each plate element (5) has a cantilever (5d), preferably of a single piece made of the same material, at the free end of which a fastening area (5e) is located, wherein a secondary support (12) is provided, in particular extending parallel to the cross member (11), which is connected to the fastening areas (5e) of the two cantilevers (5) by incorporating a crash element (13) in each case.

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