Motor vehicle with frunk

Abstract

The invention relates to a motor vehicle (10), wherein the motor vehicle (10) has a frunk (12), wherein the frunk (12) has two side walls (26) which delimit the usable space of the frunk (12) towards one side of the motor vehicle (10).The side walls (26) of the frunk (12) are each fastened to the body of the motor vehicle (10) by means of crash elements (28, 30) arranged to the side of the frunk (12) with respect to the longitudinal direction (X) of the motor vehicle (10) and / or are designed as crash elements (28, 30) and fastened to the body of the motor vehicle (10) to the side of the frunk (12) with respect to the longitudinal direction (X) of the motor vehicle (10) in such a way that, in the event of a frontal impact of the motor vehicle (10) against an obstacle, forces generated by the frontal impact can be introduced via the frunk (12) into regions of the body of the motor vehicle (10) arranged to the side of the frunk (12) in such a way that part of the kinetic energy of the motor vehicle (10) can be dissipated by the crash elements (28, 30).

Description

[0001] The invention relates to a motor vehicle with a frunk according to the preamble of claim 1.

[0002] Motor vehicles with a frunk are known from the prior art. A frunk is a storage area for luggage located in the front part of the motor vehicle, in other words, in front of the passenger compartment in the longitudinal direction of the motor vehicle. The term "frunk" is a technical term from the field of automotive engineering, derived from the English words "front" and "trunk," meaning the front and trunk, respectively.

[0003] Frunks known from the prior art are typically primarily used for luggage storage. However, since the frunk, unlike a typical trunk, is located in the area of ​​the vehicle where the deformation and destruction processes necessary for dissipating the kinetic energy take place in the event of a frontal collision, attempts have already been made in the prior art to design the frunk in such a way that it can contribute meaningfully to dissipating the vehicle's kinetic energy.

[0004] For example, DE 10 2020 006 166 A1 shows a frunk that is essentially formed by a reinforced trunk tray. Absorption elements can be arranged between the trunk tray and the bulkhead of the motor vehicle, which can dissipate the kinetic energy of the motor vehicle in the event of a frontal impact by deforming and / or destroying them.

[0005] However, the introduction of the forces transmitted in the event of a frontal impact via the trunk tray and the absorption elements into the firewall of the vehicle represents a risky measure, since the passenger cell is located directly behind this firewall, which should actually be protected as well as possible in the event of a frontal impact and should not be exposed to the risk of being pushed in towards the passenger cell.

[0006] The invention is therefore based on the object of providing a motor vehicle with a radio in which the forces absorbed via the radio in the event of a frontal impact can be better introduced into the body of the motor vehicle.

[0007] The object is achieved by a motor vehicle having the features of independent claim 1. The features of the dependent claims relate to advantageous embodiments.

[0008] The motor vehicle has a frunk. The frunk has two side walls, each of which limits the usable space of the frunk on one side of the motor vehicle.

[0009] The object is achieved in particular in that the side walls of the frunk are each fastened to the body of the motor vehicle by means of crash elements arranged to the side of the frunk with respect to the longitudinal direction of the motor vehicle and / or are designed as crash elements and fastened to the body of the motor vehicle to the side of the frunk with respect to the longitudinal direction of the motor vehicle in such a way that in the event of a frontal impact of the motor vehicle against an obstacle, forces generated by the frontal impact can be introduced via the frunk into regions of the body of the motor vehicle arranged to the side of the frunk in such a way that part of the kinetic energy of the motor vehicle can be dissipated by the crash elements.

[0010] Compared to motor vehicles known from the prior art, this type of arrangement for attaching the frunk and the crash elements has the significant advantage that the areas of the body located to the side of the frunk, into which the forces resulting from a frontal impact are introduced, enable the forces to be absorbed effectively by the rest of the body. The body structures located to the side of the frunk are located directly in front of the side areas of the passenger compartment, which generally allow good force absorption, and not directly in front of the occupants of the passenger compartment. In this way, the frunk can be used effectively to transmit comparatively large forces or to dissipate comparatively large amounts of the vehicle's kinetic energy, which would otherwise have to be transmitted or dissipated via other components of the vehicle.

[0011] For example, the crash elements and / or the side walls of the frunk can each be attached to a longitudinal member of the vehicle body. Such longitudinal members, which typically extend forward from the passenger compartment on both sides of the vehicle, represent comparatively high-strength structures of the vehicle and are therefore well suited for force transmission.

[0012] The frunk may have a trough. Troughs may serve, in particular, to form the floor and other surfaces that define the usable space of the frunk. In particular, the side walls of the frunk may be formed by sections of the trough.

[0013] Such a tray not only forms a boundary surface of the usable space of the frunk, but due to its three-dimensional shape can also be designed with regard to the absorption and transmission of forces or the possible integration of the crash elements into the side walls. In this context, the tray can in particular be designed as a single piece. A single-piece design of the tray in this context refers in particular to the single-piece design of the surfaces of the tray that delimit the usable space. The tray can be made of a plastic and / or a metallic material. In this case, the tray can in particular have reinforcements to enable the transmission of forces, particularly in the area where the tray is attached to the body of the motor vehicle.

[0014] The motor vehicle can have a cross member arranged in the longitudinal direction of the motor vehicle in front of the frunk and fastened to the body of the motor vehicle. The cross member is designed in particular to absorb forces generated by a frontal impact of the motor vehicle with an obstacle and to transmit them to the body of the motor vehicle. Such cross members are also referred to as bumper cross members or bumper cross members. They are mechanically relatively highly resilient components which correspond to the original bumpers in their function, but in modern motor vehicles are usually located behind a row of trim elements. The cross member is arranged in particular in front of the frunk so that the frunk is initially protected by the cross member in the event of a frontal impact.In the event of a frontal collision with a sufficiently low impact speed, the frunk can initially be protected from damage and the repair costs caused by the frontal collision can be limited.

[0015] However, the trim elements that may be arranged in front of the cross member are only designed to dissipate the kinetic energy of the vehicle in the event of a frontal collision with an extremely low impact speed. This typically involves a slight impact against an obstacle, as can occur, for example, when parking. In cases where the impact speed is so high that the occupants must be protected by the dissipation of kinetic energy using crash elements designed for this purpose, such trim elements no longer play a significant role but are usually simply destroyed, so that the cross member that then hits the obstacle can absorb the forces and transfer them to the body in such a way that the kinetic impact energy is dissipated in the most controlled way possible through the deformation of the elements of the vehicle designed for this purpose or their destruction.

[0016] The cross member can be attached to the body via crash boxes so that when the vehicle collides head-on with an obstacle, the forces generated by the frontal impact can be transferred from the cross member via the crash boxes into the body of the vehicle, while the kinetic energy of the vehicle can be dissipated by the crash boxes. With such a design, the dissipation of kinetic energy through deformation and / or destruction of components can be concentrated to a certain extent on the crash boxes. This allows for the creation of well-defined deformation behavior, and for the comparatively inexpensive crash boxes to be deliberately "sacrificed" to protect structures, such as the longitudinal members of the vehicle body, from damage or even destruction, in order to keep the costs of repairing the vehicle resulting from the frontal impact as low as possible.

[0017] The cross member can be attached to the longitudinal members of the vehicle body. The longitudinal members provide a resilient structure, allowing forces from the cross member to be effectively transmitted to the rest of the vehicle body. Second, when viewed from above, the longitudinal members and the cross member form a type of frame within which a frunk can be advantageously positioned. This allows for a relatively large amount of space inside the frunk for luggage, as the forces acting on the vehicle body in the event of a frontal impact can be absorbed by structures arranged around this space.

[0018] In this context, the absorption and transmission of forces via the side walls of the frunk also proves advantageous, as the force transmission and the dissipation of kinetic energy also occur to the side of the usable space of the frunk, and thus the forces absorbed and transmitted via the frunk are also absorbed and dissipated in the area of ​​the side members. This allows for a comparatively large usable space in the frunk while simultaneously providing good crash characteristics in the event of a frontal impact. The cross member can be attached to the side members, particularly via the crash boxes. This way, the side members can be protected, at least in certain accident scenarios.

[0019] The cross member can be spaced from the frunk in the longitudinal direction of the motor vehicle so that the cross member can initially move towards the frunk in a frontal impact before forces generated by the frontal impact of the motor vehicle with an obstacle are transmitted via the cross member into the frunk. This measure can initially protect the frunk from damage in a frontal impact where the impact speed does not exceed a certain value. In this way, the frunk is only functionally involved in the dissipation of kinetic energy in the event of a frontal impact when this is truly necessary to protect the occupants, whereas in a less severe frontal impact, damage to the frunk is initially avoided.In the event of a severe frontal impact, the cross member then hits the frunk, so that forces can be transmitted from the cross member via the frunk to the body of the vehicle.

[0020] The cross member can be spaced from the tub in the longitudinal direction of the motor vehicle so that in the event of a frontal impact, the cross member can initially move towards the tub before forces generated by the frontal impact of the motor vehicle against an obstacle are transmitted via the cross member into the tub. In the event that the frunk has a tub, such an arrangement is sensible because in the event of a frontal impact that falls below a certain impact speed, damage to the tub can initially be avoided because it is protected by the cross member arranged in front of the tub, and this cross member must first move towards the tub before forces can be transmitted via the cross member into the tub.

[0021] Accordingly, the motor vehicle can be designed in such a way that, in the event of a frontal impact of the motor vehicle against an obstacle, forces generated by the frontal impact can be introduced into the body on each side of the motor vehicle via a first load path leading via the frunk and via a second load path leading via the attachment of the cross member to the body and thus in particular via the crash boxes.

[0022] The motor vehicle is, in particular, designed such that, in the event of a frontal impact of the motor vehicle against an obstacle at an impact speed that does not exceed a certain limit, the forces generated by the frontal impact are transmitted only via the second load path, and only when the limit is exceeded are the forces transmitted via both load paths. In this context, the motor vehicle can, in particular, be designed such that the transmission of forces via the first load path begins with a time delay compared to the transmission of forces via the second load path. This can be achieved, for example, as described above, by spacing the cross member from the frunk.

[0023] The motor vehicle can be designed in such a way that in a frontal impact at 50 km / h and 100% overlap according to Euro NCAP, at least 3% of the kinetic energy which is dissipated in total as part of the transmission of the forces generated by the frontal impact via the load paths on the first and second load paths is dissipated on the first load path.

[0024] The crash elements can be fiber composite structures. Fiber composite structures are suitable for the targeted dissipation of kinetic energy through delamination. Through the layer structure and the targeted selection of fiber orientations, the dissipation of kinetic energy can be specifically controlled, for example, a progressive behavior or a stiffness that decreases along the direction of force can be created.

[0025] Furthermore, the crash elements can be cellular structures. Cellular structures demonstrate a benign failure behavior, since deformation of a cellular structure requires the deformation or destruction of numerous individual cell walls. This allows energy to be dissipated evenly and in a controlled manner over a deformation path.

[0026] Alternatively and / or additionally, the crash elements can be honeycomb structures. Honeycomb structures are also well suited for energy absorption, and due to their anisotropic design, they exhibit a clear preferred direction. Honeycomb structures can therefore be used specifically to achieve specific properties with regard to energy dissipation and force transmission, depending on their orientation.

[0027] Alternatively and / or additionally, the crash elements can be structures designed to dissipate kinetic energy through bulging. Such structures can be made, in particular, of metallic materials or other materials with ductile properties. The kinetic energy of the vehicle can then be dissipated through plastic deformation of these structures, which creates a wrinkle-like structure (so-called bulging). Such structures have a targeted shape that leads to the desired bulging in the event of failure. This can, for example, be deformations introduced into the structures, for example in the form of beads, which act as the starting point for the formation of the bulging in the event of failure.

[0028] Further practical embodiments of the invention are described below in conjunction with the drawings. They show: Fig. 1 a schematic perspective view of a front end of an exemplary motor vehicle, Fig. 2 a sectional view through part of an exemplary frunk with a side wall designed as a crash element, Fig. 3 a schematic representation of a plan view of a frunk attached to a body of the motor vehicle by means of a crash element.

[0029] The Fig. The motor vehicle 10 illustrated by way of example in Figure 1 has a frunk 12. The frunk 12 can be formed by a trough 14, as in the example shown. A cross member 16 can be arranged in front of the frunk 12 in the longitudinal direction X of the motor vehicle 10. The cross member 16 can be attached to longitudinal members 20 of the motor vehicle 10 via crash boxes 18, as in the example shown.

[0030] In Fig. 1, a first load path 22 and a second load path 24 are schematically shown. The exemplary motor vehicle 10 can be configured such that, in the event of a frontal impact of the motor vehicle 10 against an obstacle, forces generated by the frontal impact on each side of the motor vehicle 10 can be introduced into the body of the motor vehicle 10 via such a first load path 22, which leads via the frunk 12, and via the second load path 24, which leads via the attachment of the cross member 16 to the body of the motor vehicle 10.

[0031] In the example shown, the second load path 24 can lead from the cross member 16 via crash boxes 18 to longitudinal members 20 of the body of the motor vehicle 10.

[0032] As exemplified in the Fig. 2, the side walls 26 of the frunk 12 can be designed as crash elements 28 such that, in the event of a frontal impact of the motor vehicle against an obstacle, forces generated by the frontal impact can be introduced via the frunk 12 into areas of the body of the motor vehicle 10 arranged to the side of the frunk 12 such that a part of the kinetic energy of the motor vehicle 10 can be dissipated by the crash elements 28. As in the Fig. 2, the side wall 26 of the frunk 12 may have a honeycomb structure within the side wall 26, by which the side wall 26 is formed as a crash element 28.

[0033] Alternatively and / or additionally, as shown schematically in the Fig. 3, the side walls 26 of the frunk 12 are each fastened to the body of the motor vehicle 10 by means of crash elements 30 arranged to the side of the frunk 12 with respect to the longitudinal direction X of the motor vehicle 10 in such a way that in the event of a frontal impact of the motor vehicle 10 against an obstacle, forces generated by the frontal impact can be introduced via the frunk 12 into regions of the body of the motor vehicle 10 arranged to the side of the frunk 12 in such a way that a portion of the kinetic energy of the motor vehicle 10 can be dissipated by the crash elements 30. The introduction of the forces into the body of the motor vehicle 10 can take place in the longitudinal member 20 of the body of the motor vehicle 10, as in the example shown.

[0034] For display reasons, crash elements 28 and 30 are shown in the Fig. 1 not visible.

[0035] As in Fig. 1, but also especially in Fig.3, the cross member 16 may be offset from the frunk 12 in the longitudinal direction X of the motor vehicle 10. As in the example shown, this may mean, in particular, that the cross member 16 is offset from the tub 14 in the longitudinal direction X of the motor vehicle 10. Thus, in the case of a frontal impact, the cross member 16 may initially move toward the frunk 12, in particular toward the tub 14 as in the example shown, before forces generated by the frontal impact of the motor vehicle 10 upon a frontal impact with an obstacle are transmitted via the cross member 16 into the frunk 12, in particular into the tub 14. This results in the kinetic energy of the motor vehicle 10 initially being dissipated only on the second load path 24 and only when the cross member 16 has moved a certain distance towards the frunk 12 or the tub 14 does the additional dissipation of the kinetic energy take place on the first load path 22.

[0036] The dissipation of the kinetic energy takes place in particular on the first load path 22 via the side walls 26 of the frunk 12, designed as crash elements 28, and / or via the crash elements 30, by means of which the side walls 26 of the frunk 12 are fastened to the body of the motor vehicle 10. The dissipation of the kinetic energy on the second load path 24 can take place, as in the example shown, in particular via crash boxes 18, by means of which the cross member 16 is fastened to the body of the motor vehicle 10, in particular, as in the example shown, to longitudinal members 20 of the body of the motor vehicle 10.

[0037] The features of the invention disclosed in the present description, the drawings, and the claims may be essential, both individually and in any combination, for the realization of the invention in its various embodiments. The invention may be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art. List of reference symbols 10 motor vehicle 12 Frunk 14 tub 16 cross members 18 crash boxes 20 longitudinal members 22 first load path 24 second load path 26 Side wall 28 Crash element 30 crash element X Longitudinal direction 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 10 2020 006 166 A1

[0004]

Claims

[1] Motor vehicle (10), wherein the motor vehicle (10) has a frunk (12), wherein the frunk (12) has two side walls (26) which delimit the usable space of the frunk (12) towards one side of the motor vehicle (10), characterized bythat the side walls (26) of the frunk (12) are each fastened to the body of the motor vehicle (10) by means of crash elements (30) arranged to the side of the frunk (12) with respect to the longitudinal direction (X) of the motor vehicle (10) and / or are designed as crash elements (28) and fastened to the body of the motor vehicle (10) to the side of the frunk (12) with respect to the longitudinal direction (X) of the motor vehicle (10) in such a way that in the event of a frontal impact of the motor vehicle (10) against an obstacle, forces generated by the frontal impact can be introduced via the frunk (12) into regions of the body of the motor vehicle (10) arranged to the side of the frunk (12) in such a way that part of the kinetic energy of the motor vehicle (10) can be dissipated by the crash elements (28, 30). [2] Motor vehicle (10) according to claim 1, characterized bythat the crash elements (28, 30) and / or side walls of the frunk (12) are each fastened to a longitudinal member (20) of the body of the motor vehicle (10). [3] Motor vehicle (10) according to claim 1 or 2, characterized by that the frunk (12) has a trough (14), in particular one-piece, and the side walls (26) of the frunk (12) are formed by areas of the trough (14). [4] Motor vehicle (10) according to one of the preceding claims, characterized by in that the motor vehicle (10) has a cross member (16) which is arranged in the longitudinal direction (X) of the motor vehicle (10) in front of the frunk (12), in particular in front of the tub (14), and is fastened to the body of the motor vehicle (10), which cross member is designed to absorb forces generated by the frontal impact in the event of a frontal impact of the motor vehicle (10) against an obstacle and to introduce them into the body of the motor vehicle (10). [5] Motor vehicle (10) according to one of the preceding claims, characterized bythat the cross member (16) is fastened to the body of the motor vehicle (10) via crash boxes (18), so that when the motor vehicle (10) collides head-on with an obstacle, forces generated by the frontal impact can be introduced from the cross member (16) via the crash boxes (18) into the body of the motor vehicle (10) and part of the kinetic energy of the motor vehicle (10) can be dissipated by the crash boxes (18). [6] Motor vehicle (10) according to one of the preceding claims, characterized by that the cross member (16), in particular via the crash boxes (18), is fastened to the longitudinal members (20) of the body of the motor vehicle (10), [7] Motor vehicle (10) according to one of the preceding claims, characterized byin that the cross member (16) is spaced apart in the longitudinal direction (X) of the motor vehicle (10) from the frunk (12), in particular from the tub (14), so that in the case of a frontal impact the cross member (16) can first move towards the frunk (12), in particular towards the tub (14), before forces generated by the frontal impact of the motor vehicle (10) against an obstacle are introduced via the cross member (16) into the frunk (12), in particular the tub (14). [8] Motor vehicle (10) according to one of the preceding claims, characterized bythat the motor vehicle (10) is designed in such a way that, in the event of a frontal impact of the motor vehicle (10) against an obstacle, forces generated by the frontal impact can be introduced into the body on each side of the motor vehicle (10) via a first load path (22) which leads via the frunk (12) and via a second load path (24) which leads via the fastening of the cross member (16) to the body and in particular via the crash boxes (18). [9] Motor vehicle (10) according to one of the preceding claims, characterized by that in a frontal impact at 50 km / h and 100% overlap according to Euro NCAP, at least 3% of the kinetic energy which is dissipated on the two load paths (22, 24) as part of the transmission of the forces generated by the frontal impact via both load paths (22, 24) is dissipated on the first load path (22). [10] Motor vehicle (10) according to one of the preceding claims, characterized bythat the crash elements (28, 30) are fiber composite structures, cellular structures, honeycomb structures and / or structures designed to dissipate kinetic energy by folding.

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