Front wall crossmember for a motor vehicle body

Abstract

Front wall cross member (1) for a motor vehicle body (2), which extends in one piece over a vehicle width, characterized in that the front wall cross member (1) is designed as an arc-shaped structural element for a frontal impact to transfer forces in the longitudinal direction (3) of the motor vehicle, wherein the front wall cross member (1) has a convex curvature in the direction of travel (6) of the motor vehicle, spans the vehicle width without supports and can be mounted on the motor vehicle body (2) with end sections (4).

Description

[0001] The invention relates to a front wall crossmember for a motor vehicle body. The invention also relates to a motor vehicle with such a front wall crossmember.

[0002] Generally, a vehicle comprises two laterally positioned A-pillars and a bulkhead between them. The bulkhead serves to separate the front of the vehicle from the passenger compartment. Vehicles may also include a central tunnel, which can serve to stiffen the vehicle's floor pan and accommodate a drivetrain component, such as a driveshaft.

[0003] Typically, the A-pillars, firewall, center tunnel, and floor panel are made of different components. To create a rigid vehicle structure, these components must be connected. A firewall crossmember, which forms part of the firewall structure, serves primarily to stiffen the structure and protect against frontal impacts.

[0004] German patent DE 10 2012 014 117 A1 discloses a motor vehicle with a front wall crossmember, essentially W-shaped in the longitudinal direction of the vehicle and arranged above a central tunnel. This crossmember is fixed at its ends to the A-pillars of the vehicle body. In its central area, the front wall crossmember has an enlarged bearing surface and is connected to the front wall of the vehicle body, so that in the event of a collision, central support is provided by the front wall. In electrically powered vehicles, a central tunnel may be omitted. Therefore, the front wall can have a different shape.

[0005] From DE 10 2020 108 523 A1, a front structure for a motor vehicle with an energy storage system is known, wherein the front wall is formed from two mutually supporting beams. The stability, which is normally provided by the central tunnel, is thereby achieved by the two vertically supporting beams.

[0006] The object of the present invention is now to provide a front wall cross member and a motor vehicle which overcomes the aforementioned disadvantages.

[0007] According to the invention, this problem is solved by a front wall crossmember for a motor vehicle body with the features of claim 1. Advantageous embodiments and further developments are described in the dependent claims. A motor vehicle with such a front wall crossmember is also described.

[0008] At its core, the front wall cross member according to the invention is designed as an arc-shaped structural element for a frontal impact to transfer forces in the longitudinal direction of the motor vehicle, wherein the front wall cross member has a convex curvature in the direction of travel of the motor vehicle, spans the vehicle width without supports and can be mounted with end sections on the motor vehicle body.

[0009] Such a front bulkhead crossmember is therefore particularly suitable for electrically powered vehicles that are designed without a center tunnel or without a tunnel at all. The arched shape spanning the width of the vehicle allows for higher force absorption and transmission, enabling the front bulkhead crossmember to extend across the width of the vehicle without additional support. Furthermore, the front bulkhead crossmember is preferably manufactured as a single piece, which also ensures high force transmission.

[0010] In particular, the front bulkhead crossmember forms a central structural element designed to withstand a frontal impact. For example, longitudinal forces of up to 400 kN can be absorbed by the front bulkhead crossmember and transferred to the vehicle body via its end sections. Support from a central tunnel is unnecessary because the front bulkhead crossmember itself is inherently stable due to its arched shape.

[0011] The front bulkhead crossmember is designed for a vehicle body and extends in one piece across the entire width of the vehicle. This eliminates the need for support from a central tunnel. In particular, longitudinal support across the vehicle's width is not required. Advantageously, this frees up additional installation space inside the vehicle. Furthermore, it results in weight savings due to a reduction in the number of components. In the case of electrically powered vehicles where a battery is located in one plane of the vehicle, additional installation space can be freed up for further batteries, as the floor support in the underbody can be omitted.

[0012] Preferably, the bulkhead crossmember can be mounted on the A-pillars of the vehicle body. The end sections, which are located on two opposite sides of the bulkhead crossmember, can each be directly force-transmittingly mounted to an A-pillar. This allows the force to be transmitted from the bulkhead crossmember via the A-pillars into the main floor and the side wall without the need for support from a central tunnel. The contact points between the end sections and the A-pillars must be designed for force transmission. Therefore, a force-transmitting fastening with sufficiently robust fasteners or welded connections is advantageous.

[0013] Due to the convex curvature of the front wall cross member according to the invention in the direction of travel of the motor vehicle, i.e. the arc shape is therefore particularly designed in the direction of travel, a statically stable structure can be provided in the event of a frontal impact.

[0014] In another embodiment, the arc shape can be designed such that it has a curvature-free section in the region of the vehicle's central axis. Accordingly, a flat surface can be formed in the region of the vehicle's central axis, to which curved sections adjoin in the direction of the end sections of the front wall crossmember. Regardless of the embodiment, however, it is advantageous if the front wall crossmember projects forward in the direction of travel in the region of the vehicle's central axis at least as far as in the areas located to the right and left of it. This ensures that forces from a frontal impact can be safely absorbed and transferred into the vehicle structure, i.e., into the main floor and the side wall.

[0015] In an advantageous embodiment, the convex curvature can have a vertex in the center of the vehicle. If the arc shape of the front wall crossmember is designed without a straight section, the arc shape can have a vertex on the vehicle's central axis. This also ensures that the central area projects forward in the direction of travel at least as far as the areas to its right and left.

[0016] A further advantageous embodiment can provide that the front wall crossmember is designed for a vehicle with an energy storage device, wherein the front wall crossmember can be arranged at the same installation height as the energy storage device in the vehicle. In particular, this makes it advantageously possible to dispense with an additional floor crossmember. The front wall crossmember can, for example, have a kind of receiving area behind the arched shape, which, viewed in the direction of travel, is formed behind the front wall crossmember. This allows the front wall crossmember to have, for example, an L-shaped cross-section, at least in sections, such that one section of the front wall crossmember is oriented towards the main floor, and another section is oriented transversely to it.

[0017] According to a highly advantageous further development of the idea, it can be designed for a motor vehicle without a central tunnel. Such a vehicle is, in particular, an electric vehicle that has several battery modules in the area of ​​the main floor. By eliminating the central tunnel, the area for accommodating such battery modules can be increased, thereby improving the vehicle's range.

[0018] The invention further relates to a motor vehicle with an energy storage device, comprising a front wall crossmember according to the invention. The motor vehicle is designed without a central tunnel, wherein the front wall crossmember spans one vehicle width of the motor vehicle without supports and is mounted at its end sections on the A-pillars of the motor vehicle.

[0019] In an advantageous embodiment, the front wall crossmember can be arranged at the same installation height as the energy storage unit in the vehicle. Since the front wall crossmember does not project into the area of ​​the main floor against the direction of travel and require installation space there, the installation area for battery modules can be increased.

[0020] The same advantages and features apply to the motor vehicle as already described with regard to the front wall cross member.

[0021] Further advantageous embodiments of the front wall cross member and the motor vehicle according to the invention also become apparent from the exemplary embodiment, which is described in more detail below with reference to the figures. These show: Fig. 1 an embodiment of an end wall cross member for a vehicle; Fig. 2 another view of an end wall crossbeam; and Fig. 3 Another view of an end wall crossbeam.

[0022] In the presentation of the Fig. Figure 1 shows a possible embodiment of the front wall crossmember 1 in a front view. The front wall crossmember 1 is arc-shaped and spans the width of the vehicle, extending vertically upwards from a plane 8, which can, for example, form the main floor. This allows a structural element to be formed that is designed to absorb and transmit vertically impacting forces from a frontal collision. The front wall crossmember 1 is integrated into a body, as shown in Figure 1. Fig. 2 shown, wherein it is supported by end sections 4 on the vehicle body 2.

[0023] Another view of the end wall crossbeam 1 is shown in Fig. 2. The same components are marked with the same reference symbols, so this does not need to be discussed in detail. In this, the end sections 4 are visible, which are supported by the A-pillars 5 (shown schematically). This allows the front wall cross member 1 to run across the width of the vehicle without supports, thus eliminating the need for support against a central tunnel. Fig. Figure 2 further shows that the arc shape is formed in the direction of a longitudinal direction 3 as well as in the direction of travel 6 of the vehicle. In the illustrated embodiment, the front wall cross member 1 has a straight section on a central axis of the vehicle, which in the illustration is formed on the axis with reference numeral 3, that transitions to an arc-shaped section on the right and left. This also allows an arc shape to be formed, which is convexly curved in the direction of travel 6.

[0024] In another embodiment, the front wall cross member 1 can be designed without this straight section, wherein a vertex 7 of the arc shape or convex curvature can be located on the central axis (represented by the axis 3) of the vehicle. Fig. 3 this is evident, whereby Fig. Figure 3 shows a cross-sectional view through the end wall crossbeam 1.

[0025] For example, it is possible that the end wall crossbeam 1 is designed in a section plane with such a vertex 7, and has a straight section in another different section plane, as shown with respect to Fig. 2 described. In particular, the arched shape of the end wall crossbeam 1 can thereby be adapted to the forces to be transmitted.

Claims

[1] Front wall cross member (1) for a motor vehicle body (2), which extends in one piece over the width of the vehicle, characterized by , that the front wall cross member (1) is designed as an arc-shaped structural element for a frontal impact to transfer forces in the longitudinal direction (3) of the motor vehicle, wherein the front wall cross member (1) has a convex curvature in the direction of travel (6) of the motor vehicle, spans the vehicle width without supports and can be mounted on the motor vehicle body (2) with end sections (4). [2] Front wall crossbeam (1) according to claim 1, characterized by , that the front wall cross member (1) can be mounted on the A-pillars (5) of the motor vehicle body (2). [3] Front wall crossbeam (1) according to claim 1, characterized by , that the convex curvature has a vertex (7) in the center of the vehicle. [4] End wall crossbeam (1) according to one of claims 1 to 3, characterized by, that this is designed for a vehicle with an energy storage device, wherein the front wall cross member (1) can be arranged at an installation height of the energy storage device in the motor vehicle. [5] End wall crossbeam (1) according to any one of claims 1 to 5, characterized by that it is designed for a motor vehicle without a central tunnel. [6] Motor vehicle with an energy storage device comprising a front wall cross member (1) according to any one of claims 1 to 5, characterized by , that the motor vehicle is designed without a central tunnel, wherein the front wall cross member (1) spans one vehicle width of the motor vehicle without supports and is supported at end sections (4) on the A-pillars (5) of the motor vehicle. [7] Motor vehicle according to claim 6, characterized by , that the front wall cross member (1) is arranged at an installation height of the energy storage unit in the motor vehicle.

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