Vehicle substructure and motor vehicle

Abstract

Vehicle substructure (1) with at least one bodyshell structure (2) and with at least one crash box (3) connected to the bodyshell structure (2) for converting kinetic energy resulting from an impact into deformation work, wherein at least one at least partially reversibly deformable damping element (4) is arranged between the bodyshell structure (2) and the crash box (3) in order to counteract an overload of the bodyshell structure (2) in the event of an impact, and wherein the crash box (3) is arranged between the damping element (4) and at least one attachment (6), wherein the crash box (3) and the damping element (4) are screwed to the bodyshell structure (2) via at least one common fastening means (7), and wherein the damping element (4) is suitable and designed to reduce at least one maximum (15) of a force-displacement curve (5) of the crash box (3) by means of a reversible deformation of the damping element (4),which lies in a first half of a path provided by the crash box for deformation.

Description

[0001] The present invention relates to a vehicle substructure with at least one body shell structure and with at least one crash box connected to the body shell structure, as well as to a motor vehicle.

[0002] Motor vehicles equipped with a CMS (Crash Management System) are now well established. This is designed to minimize damage in accidents, especially low-speed crashes, and thus enable the most cost-effective repairs.

[0003] Typically, the CMS includes one or more crash boxes that dissipate crash energy or convert it into deformation energy, preventing damage to the body shell and various attachments. Repairs often only require replacing the CMS and the damaged attachments. Permanent or irreversible damage to the body shell, such as plastic deformation, can be avoided in many cases.

[0004] For example, DE 197 00 022 A1 discloses a bumper assembly for a motor vehicle in which a bumper is attached to the front ends of the body longitudinal members on both sides via two deformation members connected in series. A first deformation member, associated with a low-speed impact, is formed by an elastically deformable damper part. A second deformation member, associated with a high-speed impact, is formed by a permanently deformable crumple part.

[0005] DE 699 24 259 T2 shows an end module assembly of a motor vehicle with two rail sections. A gap and a force isolator in the form of a rubber mass are provided between the rail sections for dynamic decoupling. The force isolator and the gap enable relative movements between the rail sections.

[0006] DE 297 10 488 U1 discloses a device for absorbing impact energy for the suspension of a vehicle bumper. The device comprises a cover profile attached to the vehicle, which converts the impact energy into deformation energy. An elastically and / or plastically deformable deformation body is arranged at the end region of the cover profile opposite the fastening side. The bumper is attached to the deformation body. In the event of an impact, the deformation body deforms first before the shape of the cover profile changes, thus avoiding force peaks in the force-displacement curve.

[0007] DE 198 31 708 A1 discloses a bumper assembly for a motor vehicle in which the bumper cross member is located directly behind its panel. The cross member is flexibly connected to a crash box by means of a structural unit. The crash box is attached directly to the body. The structural unit comprises a compressible foam in a rigid, rigid casing.

[0008] However, it has been observed that the known systems cannot always reliably prevent unwanted damage to the shell and therefore require improvement.

[0009] It is therefore the object of the present invention to provide an improved possibility for counteracting undesirable bodyshell damage caused by impact events and in particular by low-speed crash events.

[0010] This object is achieved by a vehicle substructure having the features of claim 1 and by a motor vehicle according to claim 7. Preferred developments are the subject of the subclaims. Further advantages and features of the present invention will become apparent from the general description and the description of the exemplary embodiment.

[0011] The vehicle part structure according to the invention comprises at least one bodyshell structure and at least one crash box connected to the bodyshell structure. The crash box serves in particular to convert kinetic energy resulting from an impact into deformation work. At least one at least partially reversibly deformable damping element is arranged between the bodyshell structure and the crash box. The damping element is suitable and designed to counteract excessive loading of the bodyshell structure in the event of an impact. The crash box is arranged between the damping element and at least one add-on part. The crash box and the damping element are screwed to the bodyshell structure via at least one common fastening means. The damping element is suitable and designed to reduce or equalize at least one maximum of a force-displacement curve of the crash box by means of reversible deformation of the damping element.which lies in a first half of a path provided by the crash box for deformation.

[0012] The vehicle component structure according to the invention offers many advantages. A significant advantage is that unwanted body shell damage can be completely avoided or at least significantly reduced. This minimizes damage in accidents, especially in low-speed crashes, and enables particularly cost-effective repairs.

[0013] According to the invention, the damping element is suitable and designed to reduce or dampen at least one maximum of a force-displacement curve of the crash box. Such a configuration is particularly advantageous because it has been shown that such a maximum often represents a particularly critical overload, which frequently leads to undesirable structural damage. The maximum refers in particular to a force peak or overshoot that occurs during the conversion of the kinetic energy resulting from the impact into deformation work. The damping element can also be suitable and designed to reduce or dampen at least two or three or more maxima.

[0014] According to the invention, the maximum to be reduced or dampened lies in a first half and particularly preferably in a first third of a path provided by the crash box for deformation. It is also possible for the maximum to lie in a first quarter and in particular in a first fifth or sixth, or even in a first eighth of the path provided by the crash box for deformation.

[0015] The damping element is preferably suitable and designed to at least partially prevent, and preferably completely prevent, overloading of the bodyshell structure under the conditions of an RCAR structural test (RCAR: Research Council for Automobile Repairs). Such a configuration is particularly advantageous because the RCAR structural test is particularly relevant to the design of the crash behavior of a motor vehicle or a CMS. Avoiding overloading during the RCAR structural test therefore represents a significant advantage and offers significantly cheaper repairs and vehicle maintenance. In particular, the damping element is suitable and designed to dampen or prevent a maximum in the force-displacement curve occurring under the conditions of the RCAR structural test.

[0016] Preferably, the damping element is suitable and designed to counteract the overloading of the bodyshell structure without itself suffering permanent deformation. This provides particularly economical and reliable crash management. In particular, the damping element is suitable and designed to dampen the overloading without deformation. In particular, the damping element is suitable and designed to counteract the overloading by means of damping action. It is preferred that the damping element not have a rigid and / or deformable casing.

[0017] According to the invention, the damping element is at least partially reversibly deformable and, in particular, is completely reversibly deformable. Such a damping element can be provided cost-effectively and offers an advantageous damping effect. The damping element is, in particular, elastically deformable. It is possible for the damping element to have at least one elastomer and / or at least one elastomer-like component. In particular, the damping element is suitable and designed to counteract overloading of the bodyshell structure by means of reversible deformation. In particular, the maximum of the force-displacement curve is damped by means of reversible deformation of the damping element.

[0018] According to the invention, the damping element is screwed to the bodyshell structure. The damping element can also be attached to the crash box, in particular by screwing. This provides reliable fastening and uncomplicated assembly. At least one additional fastening means is also possible. According to the invention, the crash box and the damping element are attached to the bodyshell structure via at least one common fastening means.

[0019] In all embodiments, it is particularly preferred that the crash box at least partially converts the kinetic energy resulting from the impact by means of bulging. This provides particularly effective and reliable energy dissipation. It is also possible for the crash box to convert the kinetic energy by means of at least one other deformation behavior.

[0020] It is possible for the bodyshell structure to comprise at least one bodyshell longitudinal member and / or at least one bodyshell cross member. The crash box is arranged and, in particular, fastened to the bodyshell longitudinal member and / or the bodyshell cross member.

[0021] According to the invention, the crash box is arranged between the damping element and at least one attachment. In particular, the crash box is at least partially connected to the attachment and, in particular, at least partially fastened to the attachment, or vice versa. The attachment comprises, in particular, at least one attachment cross member and / or at least one attachment longitudinal member. It is possible for the attachment to be designed as a bumper or to at least comprise one such bumper. Other attachments are also possible.

[0022] The motor vehicle according to the invention is designed in particular as a passenger car. The vehicle comprises at least one vehicle substructure as described above.

[0023] The motor vehicle according to the invention offers many advantages, allowing, for example, particularly economical repair of damage caused by a low-speed crash. Furthermore, such a vehicle can be maintained particularly economically.

[0024] The vehicle substructure is preferably designed as a crash management system (CMS) or is at least a part of a CMS. The vehicle substructure can also comprise at least one CMS. It is also possible for two or more vehicle substructures to be assigned to a CMS of a motor vehicle.

[0025] In particular, the damping element is arranged between the bodyshell structure and the crash box in such a way that a force flow from the crash box via the damping element to the bodyshell structure is possible. In particular, the damping element is arranged between the bodyshell structure and the crash box in the direction of the force of an expected impact. In particular, a force or impact energy can be introduced into the damping element via the crash box. In particular, a force or impact energy can be introduced into the bodyshell structure via the damping element.

[0026] Further advantages and features of the present invention will become apparent from the embodiment which will be explained below with reference to the accompanying figures. Fig. 1 a highly schematic representation of a vehicle part structure according to the invention; Fig. 1a a highly schematic representation of the vehicle part structure on a motor vehicle in a plan view; Fig. 2 an exemplary and highly schematic sketch of a force-displacement curve of a vehicle part structure according to the invention; and Fig. 3 an exemplary and highly schematic sketch of a force-displacement curve of a vehicle substructure from the state of the art.

[0027] The Fig. 1 shows a vehicle part structure 1 according to the invention, as it is installed, for example, on a motor vehicle according to the invention.

[0028] The vehicle substructure 1 here comprises a bodyshell structure 2 and a crash box 3.

[0029] The crash box 3 is part of a crash management system 10 of a motor vehicle. For this purpose, the crash box 3 is coupled, for example, directly or indirectly to an attachment 6. The attachment 6 can be designed, for example, as a bumper or the like. The attachment 6 can have at least one attachment cross member and / or at least one attachment longitudinal member, which is connected to the crash box 3.

[0030] The bodyshell structure 2 can, for example, be designed as a bodyshell longitudinal member 12 or at least include one such member. The bodyshell structure 2 can also be designed as a bodyshell cross member 22 or at least include one such member.

[0031] A damping element 4 is arranged between the bodyshell structure 2 and the crash box 3. The damping element serves to counteract an overload of the bodyshell structure 2 in the event of an impact.

[0032] In one embodiment, the crash box 3 and the damping element 4 are attached to the bodyshell structure 2 via at least one fastening means 7. For example, a screw connection is provided for this purpose. However, other or additional fastening means 7 are also possible.

[0033] In the Fig. 1a shows a motor vehicle which is equipped with a vehicle substructure 1 according to the invention. The vehicle substructure 1 is, for example, as shown in Fig. 1. The longitudinal axis or X-axis of the vehicle is indicated here by a dashed-dotted line. The direction of travel is indicated by an arrow.

[0034] In this illustration, the connection of the crash box 3 together with the damping element 4 to the bodyshell structure 2 or to the add-on part 6 is particularly clearly visible. A bodyshell longitudinal member 12 and a bodyshell cross member 22 of the bodyshell structure 2 are shown here. In particular, the vehicle substructure 1 on the other vehicle half, not shown here, is designed accordingly.

[0035] The Fig. 2 and Fig. 3 each show a force-displacement curve 5, in which a force 25 was plotted against a distance or a path 35. Path 35 corresponds in particular to a path provided by the crash box 2 for deformation. The force-displacement curves shown reflect, for example, the crash progression in an RCAR structural test.

[0036] The Fig. 2 shows an exemplary course of the force-displacement curve 5 of the vehicle part structure 1 according to the invention. Fig. Figure 3, on the other hand, shows a force-displacement curve 5 of a comparable vehicle substructure from the prior art under comparable or identical crash conditions. The vehicle substructure from the prior art is characterized in particular by the fact that no damping element is arranged between the corresponding bodyshell structure and the corresponding crash box.

[0037] In the Fig. 2 and Fig. 3, a rectangular curve 45 or optimal force curve is shown in dashed lines. Such a rectangular curve 45 represents optimal energy dissipation in the force-displacement curve 5 of the crash box 3. This particularly applies to crash boxes 3 that essentially convert the impact energy by means of bulging.

[0038] The Fig. The force-displacement curve 5 shown in Figure 3 clearly shows that the energy dissipation in the crash box, or rather, the buckling, exhibits a highly nonlinear character and thus does not correspond to the optimal rectangular curve 45. The force-displacement curve 5 exhibits a maximum 15, or an overshoot, particularly at the beginning. This maximum 15, or the overshoot, often leads to undesirable bodyshell damage due to overloading, especially in RCAR structural tests.

[0039] The force-displacement curve 5 of the vehicle component structure 1 according to the invention Fig. 2, however, shows a considerably more advantageous energy input into the bodyshell structure 2. The force-displacement curve 5 comes considerably closer to the optimal rectangular curve 45.

[0040] A particular advantage of the vehicle substructure 1 according to the invention is that the unfavorable overshoot is dampened or prevented by the damping element 4 arranged between the crash box 3 and the bodyshell structure 2. The maximum 15 at the beginning or in the initial region of the curve 5 is significantly reduced by the damping element 4. By preventing the overshoot 15, damage to the bodyshell structure 2 is reliably avoided. List of reference symbols 1 Vehicle part structure 2 Shell structure 3 Crashbox 4 Damping element 5 Force-displacement curve 6 Attachment 7 Fasteners 10 Crash Management System 12 bodyshell longitudinal members 15 Maximum, overshoot 22 bodyshell cross members 25 power 35 Way 45 Rectangular gradient

Claims

[1] Vehicle substructure (1) with at least one bodyshell structure (2) and with at least one crash box (3) connected to the bodyshell structure (2) for converting kinetic energy resulting from an impact into deformation work, wherein at least one at least partially reversibly deformable damping element (4) is arranged between the bodyshell structure (2) and the crash box (3) in order to counteract an overload of the bodyshell structure (2) in the event of an impact, and wherein the crash box (3) is arranged between the damping element (4) and at least one attachment (6), wherein the crash box (3) and the damping element (4) are screwed to the bodyshell structure (2) via at least one common fastening means (7), and wherein the damping element (4) is suitable and designed to reduce at least one maximum (15) of a force-displacement curve (5) of the crash box (3) by means of a reversible deformation of the damping element (4),which lies in a first half of a path provided by the crash box for deformation. [2] Vehicle part structure (1) according to the preceding claim, wherein the maximum (15) lies in a first third of the path that can be provided by the crash box for the deformation. [3] Vehicle substructure (1) according to one of the preceding claims, wherein the damping element (4) is suitable and designed to at least partially avoid overloading of the bodyshell structure (2) at least under the conditions of an RCAR structural test (RCAR: Research Council for Automobile Repairs). [4] Vehicle part structure (1) according to one of the preceding claims, wherein the damping element (4) is suitable and designed to counteract the overloading of the bodyshell structure (2) without itself suffering permanent deformation. [5] Vehicle part structure (1) according to one of the preceding claims, wherein the crash box (2) converts the kinetic energy resulting from the impact at least partially by means of bulges. [6] Vehicle substructure (1) according to one of the preceding claims, wherein the bodyshell structure (2) comprises at least one bodyshell longitudinal member (12) and / or at least one bodyshell cross member (22). [7] Motor vehicle, in particular passenger car, comprising at least one vehicle substructure (1) according to one of the preceding claims.

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