Bending up of an arcuate cross member of a vehicle in a head-on crash

Abstract

The invention relates to a body structure for a vehicle front, having two outer main longitudinal members (5), which are connected to each other at their front end region by means of a bending cross member (11) of a bumper device, wherein an arcuately shaped cross member (1) is arranged between the main longitudinal members (5) and level with the main longitudinal members (5), as seen in the vertical direction of the vehicle, and is connected to the main longitudinal members (5). The body structure is distinguished in that a further, rear cross member (3) is arranged between the main longitudinal members (5) and level with the main longitudinal members (5), as seen in the vertical direction of the vehicle, and is connected to the main longitudinal members (5), which further, rear cross member (3) is arranged behind the arcuately shaped front cross member (1), as seen in the longitudinal direction of the vehicle, in that the arcuately shaped cross member (1) opens with its concave side forwards towards a vehicle front, and in that the front cross member (1) is fastened with its convex side to the rear cross member (3) via a connection region (7) so as to be resistant to shear.

Description

[0001] Bending of an arched cross member of a vehicle in a frontal crash

[0002] The invention relates to a body structure for a vehicle front, according to the preamble of claim 1, and to a vehicle with such a body structure.

[0003] Vehicle body structures must be designed to meet various objectives. On the one hand, they must exhibit a certain degree of rigidity for adequate support and satisfactory driving dynamics; on the other, they must be sufficiently resilient to provide self-protection for the occupants and protection for other road users involved in the accident in the event of a collision between the vehicle and another road user or a static object.

[0004] In this context, the generic EP 3 737601 B1 relates to a body structure for a passenger car having a body shell, with two longitudinal members spaced apart from one another in the transverse direction of the vehicle and with at least one bending cross member device adjoining the longitudinal members in the longitudinal direction of the vehicle, which is part of a bumper arrangement and comprises a first bending cross member and energy absorption elements fastened to the longitudinal members, via which the first bending cross member is connected to the respective longitudinal member, wherein a supporting structure is provided which is arranged between the longitudinal members and, viewed in the vertical direction of the vehicle, at the level of the longitudinal members, wherein the supporting structure has a second bending cross member which is at least indirectly connected to the longitudinal members and, viewed in plan view of the body structure, is convexly curved towards the outside of the vehicle in the direction of the first bending cross member,The supporting structure comprises a load distributor arranged in the vehicle's longitudinal direction between the first bending cross member and the second bending cross member and extending in the vehicle's transverse direction. The object of the invention is to provide a cross member unit for a vehicle front that relieves the existing structures in as many frontal crash load cases as possible and, by bending its profile, additionally absorbs forces in the vehicle's longitudinal direction.

[0005] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

[0006] A first aspect of the invention relates to a body structure for a vehicle front, with two outer main longitudinal members which are connected to one another at their front end region by means of a bending cross member of a bumper device, wherein an arc-shaped cross member is arranged between the main longitudinal members and - viewed in the vehicle vertical direction - at the level of the main longitudinal members and is connected to the main longitudinal members.The body structure is characterized in that between the main longitudinal members and - viewed in the vehicle's vertical direction - at the level of the main longitudinal members, a further rear cross member is arranged and connected to the main longitudinal members, which - viewed in the vehicle's longitudinal direction - is arranged behind the arched front cross member, that the arched cross member opens forwards towards the front of the vehicle with its concave side, and that the front cross member is attached with its convex side to the rear cross member via a connection area in a shear-resistant manner.

[0007] When assembled in the finished vehicle, the main longitudinal members are aligned along a vehicle's longitudinal axis, extending from the rear to the front. At the front of the vehicle, the front cross member and the rear cross member are arranged between the main longitudinal members. At least the front cross member is curved and opens in a crescent shape toward the front of the vehicle. The plane of the curved shape thus lies in a substantially horizontal plane.

[0008] Due to the shear-resistant connection of the front cross member and the rear cross member via a central connection area, the front cross member is bent upwards when the vehicle collides with an obstacle. This specific deformation, combined with the compression of at least one crash box, leads in particular to a straightening of the front cross member.

[0009] The shear-resistant connection of the front cross member to the rear cross member thus leads to a certain type of deformation, in particular a bending of the front arch section of the front cross member.

[0010] This advantageously reduces the effective crash length and the load on the occupants. The body structure ensures improved energy absorption in the "small overlap" load case. Furthermore, the vehicle experiences a significantly stronger lateral impulse in such a collision with only a small overlap of the collision partners, so that the overlap in the transverse direction of the vehicle between the colliding obstacle and the bodyshell or an A-pillar can be significantly reduced.

[0011] According to an advantageous embodiment, the rear cross member is arched and opens rearward towards the rear of the vehicle with its concave side, so that the front cross member and the rear cross member are connected to each other in a shear-resistant manner on their respective convex sides.

[0012] According to a further advantageous embodiment, the connection region extends around a center of an extension direction of the respective cross member.

[0013] The respective cross member extends essentially between the left and right main longitudinal members. According to this embodiment, the application area between the cross members is preferably provided in the middle of this extension length, i.e., in the middle between the main longitudinal members.

[0014] According to a further advantageous embodiment, the front cross member is connected to a respective one of the main longitudinal members by means of a respective connecting bracket.

[0015] The connecting bracket can be designed to transmit torques in order to introduce desired bending moments into the front cross member. However, degrees of freedom can also be provided, particularly around a vertical axis of the vehicle, particularly preferably limited degrees of freedom. According to a further advantageous embodiment, the connecting bracket is an extruded node and forms a force-locking connection between a respective end of the front cross member and a respective main longitudinal member.

[0016] According to a further advantageous embodiment, the connection console is connected to a crash box.

[0017] According to a further advantageous embodiment, the connection console is designed as a connection node.

[0018] A further aspect of the invention relates to a vehicle having a body structure as described above and below.

[0019] Advantages and preferred developments of the proposed vehicle result from an analogous and analogous transfer of the statements made above in connection with the proposed body structure.

[0020] Further advantages, features, and details will become apparent from the following description, which – where appropriate with reference to the drawings – describes at least one embodiment in detail. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0021] They show:

[0022] Fig. 1 shows a body structure according to an embodiment of the invention before impact with an obstacle; and

[0023] Fig. 2 the body structure according to Fig. 1 during / after impact with the obstacle.

[0024] The representations in the figures are schematic and not to scale.

[0025] Fig. 1 shows a body structure for a vehicle front of a passenger car.

[0026] The body structure is shown schematically in a plan view and aligned such that the vehicle's longitudinal axis runs from right to left in the image plane from the rear of the vehicle to the front of the vehicle. A vehicle with such a body structure is therefore heading towards an obstacle H as shown in Fig. 1. A front cross member 1 is connected in a shear-rigid manner to a rear cross member 3 along a connection area 7. The front cross member 1 is arched and arranged such that it opens towards the front of the vehicle. Accordingly, it is connected to the rear cross member 3 at its convex rear side. The connection area 7 extends in the region of a center between two main longitudinal members 5 which, aligned along the vehicle's longitudinal axis, form the lateral structural elements between which the front cross member 1 and the rear cross member 3 are located.The front cross member 1 and the rear cross member 3 are each arranged between the main longitudinal members 5 and - viewed in the vertical direction of the vehicle - at the level of the main longitudinal members 5 and are connected to the main longitudinal members 5.

[0027] The main longitudinal members 5 are connected to one another at their respective front end areas by means of a flexible cross member 11 of a bumper device. The flexible bumper cross member 11 is not directly connected to the main longitudinal members 5, but rather, respective energy absorption elements 13, also referred to as crash boxes, are provided for connecting the flexible bumper cross member 11 to the main longitudinal members 5. The two main longitudinal members 5 are connected to the front cross member 1 by means of a left and right connection console 9. These ensure a force-locking connection between the crash box (energy absorption element 13), the main longitudinal member 5, and the transverse structures. These transmit forces in the vehicle's travel and transverse directions.

[0028] Fig. 2 shows the case of a collision of a vehicle with the body structure of Fig. 1 with the obstacle H. The obstacle H is stationary and approximately infinitely stiff and immobile. The connection console 9 is displaced and rotated rearward towards the rear of the vehicle, and a corresponding force is introduced into the front cross member 1, which, however, is connected to the rear cross member 1 in a shear-rigid manner in the application area 7. Accordingly, a shear force is transferred to the rear cross member 3 in the connection area 7. In this way, the forces along the vehicle's longitudinal direction are absorbed, the front cross member 1 is bent upwards, and a desired deformation and a defined force flow or force path in the vehicle's transverse direction are set.Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, wherein the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further.

Claims

Patent claims 1. A body structure for a vehicle front, comprising two outer main longitudinal members (5) which are connected to one another at their front end region by means of a flexible cross member (11) of a bumper device, wherein an arcuate cross member (1) is arranged between the main longitudinal members (5) and - viewed in the vehicle's vertical direction - at the level of the main longitudinal members (5) and is connected to the main longitudinal members (5), characterized in that a further rear cross member (3) is arranged between the main longitudinal members (5) and - viewed in the vehicle's vertical direction - at the level of the main longitudinal members (5) and is connected to the main longitudinal members (5), which - viewed in the vehicle's longitudinal direction - is arranged behind the arcuate front cross member (1), such that the arcuate cross member (1) opens forward toward a vehicle front with its concave side,and that the front cross member (1) is rigidly attached with its convex side to the rear cross member (3) via a connection area (7).

2. Body structure according to claim 1, characterized in that the rear cross member (3) is arc-shaped and opens rearwardly towards the rear of the vehicle with its concave side, so that the front cross member (1) and the rear cross member (3) are connected to one another in a shear-resistant manner at their respective convex sides.

3. Body structure according to one of the preceding claims, characterized in that the connection area (7) extends around a center of an extension direction of the respective cross member.

4. Body structure according to one of the preceding claims, characterized in that the front cross member (1) is connected to a respective one of the main longitudinal members (5) by means of a respective connecting bracket (9).

5. Body structure according to claim 4, characterized in that the connecting bracket (9) is an extruded node and forms a force-fitting connection between a respective end of the front cross member (1) to a respective main longitudinal member (5).

6. Body structure according to one of claims 4 to 5, characterized in that the connecting bracket (9) is connected to a crash box.

7. Body structure according to one of claims 4 to 5, characterized in that the connection console (9) is designed as a connection node.

8. Vehicle with a body structure according to one of the preceding claims.

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