Motor vehicle front end structure and motor vehicle

Abstract

A motor vehicle front end structure (100) is disclosed, comprising a main cross member (102) extending in the vehicle transverse direction (Y), and a pedestrian-protecting cross member (104) which is situated therebelow in the vehicle vertical direction (Z) and is attached to the main cross member (102) by means of at least one connecting element (106). The motor vehicle front end structure (100) comprises, in addition to the connecting element (106), a support element (110) which extends downward in the vehicle vertical direction (Z).

Description

[0001] Description

[0002] "Motor vehicle front structure and motor vehicle"

[0003] The invention relates to a motor vehicle front structure according to the preamble of claim 1 and to a motor vehicle.

[0004] From US 2010 / 0219649 A1, a bumper of a motor vehicle is known which includes a cross member that is arranged transversely to a longitudinal member of a motor vehicle frame and can be moved from a ready position towards the motor vehicle.

[0005] From EP 1 743 812 A2 a vehicle body with a flexibly mounted front hood is known, with a hinge between the vehicle body and a side edge of the front hood, so that it can be opened about a pivot axis defined by the hinges.

[0006] From DE 102011 051 442 A1 a bumper arrangement and a method for operating a bumper arrangement are known, with which a cross member can be moved into a pedestrian protection position or into a crash position.

[0007] Furthermore, motor vehicles are known from practice that have a front-end structure with a main crossmember extending in the transverse direction (Y-direction) of the vehicle and which additionally have a pedestrian protection crossmember arranged below it in the vertical direction (Z-direction), which is attached to the main crossmember by at least one connecting element. In most cases, two connecting elements – also referred to in practice as "swan necks" – are provided, with one connecting element located in the left half of the vehicle and the other in the right half. Throughout this disclosure, the "main crossmember" refers to the main bumper crossmember, which is usually part of the crash management system (CMS).The CMS (Crash Management System) typically comprises two longitudinal member sections behind the main bumper crossmember, running lengthwise along the vehicle. These sections contain deformation elements in the form of so-called crash boxes, followed by the main longitudinal members. When designing motor vehicles, it is essential not only to comply with legal requirements for crash behavior in the relevant automotive markets, but also with internal, manufacturer-specific specifications and legal requirements for pedestrian protection. Furthermore, automotive manufacturers strive to minimize damage, particularly in low-speed accidents, by positioning costly replacement components within the vehicle structure in such a way as to prevent intrusion by other components, especially those located in front of them.

[0008] A conflict of objectives in the design of motor vehicles arises from the fact that, to absorb high forces acting from below on a pedestrian protection crossbeam, the aforementioned connecting elements between the main crossbeam and the pedestrian protection crossbeam should be designed to be rigid and have a large cross-sectional area. At the same time, for pedestrian protection against forces acting from the front, the force level that could cause displacement and / or deformation of the pedestrian protection crossbeam should be kept as low as possible. Forces acting from below, which occur particularly when the vehicle briefly touches the road surface while driving over a bump or step, should preferably also be taken into account. These forces can damage a cooling unit, which in many motor vehicles is located longitudinally behind the main crossbeam and the pedestrian protection crossbeam.

[0009] The invention is therefore based on the objective of providing a motor vehicle front structure and a motor vehicle with such a motor vehicle front structure, which can absorb high vertical forces, but at the same time keep the force level low in the event of frontal impact situations for the purpose of pedestrian protection.

[0010] The problem is solved according to the invention by the features of the independent claims. Further practical embodiments and advantages of the invention are described in connection with the dependent claims.

[0011] The vehicle front structure according to the invention comprises a main crossmember extending in the transverse direction of the vehicle (also referred to as the Y-direction) and a pedestrian protection crossmember arranged below it in the vertical direction of the vehicle (also referred to as the Z-direction). In particular, the main crossmember and / or the pedestrian protection crossmember extends over at least 50 percent of the width of the vehicle, preferably over at least 70 percent of the width of the vehicle, more preferably over at least 80 percent of the width of the vehicle, and most preferably over at least 90 percent of the width of the vehicle.

[0012] The pedestrian protection crossbeam is arranged on the main crossbeam via at least one connecting element. In particular, the pedestrian protection crossbeam is attached to the main crossbeam via the at least one connecting element.

[0013] In addition to the connecting element, the vehicle front structure has a support element that extends downwards in the upward direction of the vehicle.

[0014] In particular, the additional support element is not connected to the connecting element. Rather, in a crash, the support element provides an additional contact surface for the pedestrian protection crossmember that is decoupled from the connecting element, thus ensuring a corresponding force transmission to the rest of the vehicle's front-end structure and, in particular, to existing deformation elements.

[0015] The arrangement of the additional support element thus enables a decoupling of the functions "pedestrian protection" and "top protection", as the functions can each be optimized in the separate elements.

[0016] Furthermore, the support element can also be optimized as a ground protection device for another vehicle system, such as a cooling system, and the connecting element can be optimized for pedestrian protection. In this context, ground protection means that the support element protects the cooling system described above from damage if the vehicle, particularly the underbody, bottoms out, by absorbing and dissipating the forces.

[0017] According to one practical embodiment, the support element is connected to a body panel behind the connecting element at its upper side via a connection point, in the longitudinal direction of the vehicle. Furthermore, it extends forward and downward from this connection point in the longitudinal direction of the vehicle. Preferably, the support element has an arc-like curvature. This geometry ensures that forces acting on the support element are transferred to the aforementioned deformation element, which can then unfold largely freely (in particular by means of creases). As mentioned at the outset, the term "deformation element" in the context of the invention refers to a component specifically designed to absorb impact energy in the event of an accident and to protect the structure of the vehicle and its occupants.It is typically located in the front of the vehicle, often between the bumper and the frame or body. In practice, this crumple zone element is also frequently referred to as a "crash box".

[0018] In the event of an accident, particularly a frontal collision (also known as a front crash), the support element can rotate and / or pivot backwards around the connection point when subjected to a frontal load; i.e., the connection point and the support element are preferably designed to withstand high support forces in the upward direction of the vehicle, but to allow the support element to shift backwards even at low force levels when forces are applied from the front (e.g., pedestrian impact from the front).

[0019] Furthermore, according to one practical embodiment, the support element is rigidly connected to a deformation element that extends behind the main crossmember in the longitudinal direction of the vehicle. In particular, the support element is welded to the deformation element. Preferably, the support element is welded to the deformation element in such a way that, in a frontal collision, the support element "rolls" backward, i.e., is twisted and / or pivoted.

[0020] In a practical embodiment, the support element extends downwards in the vehicle's vertical direction at least to the same level or into a deeper area than another component, for example a cooling unit.

[0021] This design provides effective protection against ground contact for the unit, thus protecting it from damage if the vehicle bottoms out.

[0022] A further practical improvement involves the support element having a larger contact surface on its underside compared to the cross-section on its upper side. The advantage of this embodiment is that the larger contact surface achieves better force distribution when the vehicle bottoms out. The contact surface thus acts as a kind of "guide shoe" for the forces occurring during the brief contact of the vehicle.

[0023] In another practical embodiment, the support element has a U-shaped profile in cross-section. Alternatively or additionally, at least one groove is formed in the support element. Such geometries have proven particularly advantageous with regard to increasing stiffness while simultaneously optimizing the material requirements for the support element.

[0024] According to another practical embodiment, the connecting element and the support element are arranged side by side when viewed in the transverse direction of the vehicle. Such an arrangement prevents the two elements from colliding with each other, thus avoiding a collision and the associated change in stiffness when the respective elements are moved rearward in the longitudinal direction of the vehicle.

[0025] An alternative practical embodiment provides for the pedestrian protection crossbeam to have a complementary geometry to the support bracket. This alternative to side-by-side arrangement allows the elements (connecting element and support element) to be complementarily aligned in such a way that, when longitudinal forces act from the front (e.g., in a pedestrian collision), the connecting element and the support element are combined into a single functional unit and absorb energy together. This further reduces torsional stress on the main crossbeam.

[0026] According to one practical embodiment, the pedestrian protection crossbeam has a contact surface extending in both the transverse and vertical directions of the vehicle, which serves as a bearing surface for a stop surface of the support element when the pedestrian protection crossbeam is moved from front to rear in the longitudinal direction of the vehicle under the influence of a force. This embodiment improves the integration of the two elements into a functional unit in the event of a frontal collision, as described above.

[0027] The motor vehicle according to the invention has a front-end structure. The front-end structure is preferably the one described above.

[0028] The advantages and preferred designs listed with regard to the front structure of motor vehicles can therefore be applied analogously to motor vehicles and vice versa.

[0029] Further practical embodiments of the invention are described below in connection with the drawings. Figure 1 shows a perspective view of a motor vehicle front-end structure according to the invention in a front view;

[0030] Fig. 2 shows a detail of the motor vehicle front structure shown in Fig. 1;

[0031] Fig. 3 shows a perspective front view of the detail section according to Fig. 2;

[0032] Fig. 4 is a perspective top view of the detail section according to Fig. 2; and

[0033] Fig. 5 is a perspective view of the detail section according to Fig. 2 from below.

[0034] In the figures, identical or equivalent components are always marked with the same reference symbols.

[0035] Fig. 1 shows a motor vehicle front structure 100 according to the invention for a (motor vehicle not shown). The motor vehicle front structure 100 has a main cross member 102 extending in the transverse direction Y of the vehicle and a pedestrian protection cross member 104 arranged in the vertical direction Z of the vehicle below the main cross member 102. The pedestrian protection cross member 104 is arranged, in particular attached, to the main cross member 102 via at least one connecting element 106. In the embodiment according to Fig. 1, the pedestrian protection cross member 104 is connected to the main cross member 102 by two connecting elements 106.

[0036] The main crossbeam 102 and the pedestrian protection crossbeam 104 extend in particular over at least 50 percent of the width of the motor vehicle, preferably over at least 70 percent of the width of the motor vehicle, more preferably over at least 80 percent of the width of the motor vehicle, and most preferably over at least 90 percent of the motor vehicle. Thus, the two beams 102, 104, viewed in the transverse direction Y of the vehicle, preferably extend substantially over the entire front of the motor vehicle.

[0037] Furthermore, the main crossmember 102 is connected to the (not shown) body of the motor vehicle via at least one deformation element 108. The deformation element 108 is also referred to as a crash box and serves to absorb forces in the event of a frontal collision of the motor vehicle, particularly those caused by dents. The deformation element 108 is located behind the main crossmember 102 when viewed in the longitudinal direction X of the vehicle.

[0038] According to the invention, the vehicle front structure 100 has a support element 110 in addition to the connecting element 106. The support element 110 extends downwards in the vehicle's vertical direction Z. In the embodiment shown in Fig. 1, two support elements 110 are provided and arranged on the main crossmember 102. For the sake of simplicity, wherever a support element 110 is mentioned below, unless explicitly stated otherwise, this always also includes an embodiment with two support elements 110, for which the described properties and configurations apply analogously.

[0039] Furthermore, the support elements 110 are firmly connected to the respective deformation element 108 that adjoins the main crossbeam 102 in the longitudinal direction X of the vehicle. In particular, the support elements 110 are welded to the respective deformation element 108 in such a way that, in the event of a crash (frontal crash), the respective support element 110 "rolls" backwards due to the forces acting upon it in the longitudinal direction X of the vehicle, i.e., it is twisted and / or pivoted.

[0040] Fig. 2 shows the detail section D marked with a rectangle in Fig. 1 in an enlarged view.

[0041] Fig. 2 also shows the main crossbeam 102, the pedestrian protection crossbeam 104, the support element 110 and the connecting element 106 connecting the main crossbeam 102 with the pedestrian protection crossbeam 104.

[0042] As can also be seen from the detailed view shown in Fig. 2, the support element 110 is not connected to the pedestrian protection crossbeam 104, the main crossbeam 102, or the connecting element 106. Thus, the support element 110 is mechanically decoupled from the main crossbeam 102, the pedestrian protection crossbeam 104, and the connecting element 106.

[0043] The mechanical decoupling will now be explained in more detail in conjunction with Figures 3-5.

[0044] Figures 3-5 each show a perspective view of the detail shown in Figure 2. Figure 3 shows the detail in a front view, Figure 4 in a top view, and Figure 5 in a bottom view. As can be seen particularly in Figures 3 and 5, the support element 110 is arranged on the deformation element 108, in particular by welding. There is no further connection, in particular a mechanical one, to the main crossbeam 102, the pedestrian protection crossbeam 104, or the connecting element 106.

[0045] The support element 110 is - as can be seen from Figs. 3-5 - connected in the longitudinal direction X of the vehicle behind the connecting element 106 and the main cross member 102 at the top by a connection point to the deformation element 108 and via this to a body element 112.

[0046] Furthermore, the support element 110 extends forward and downward from the connection point in the longitudinal direction X of the vehicle. In other words, the support element 110 is curved in an arc shape, as can be seen particularly in Figures 3 and 5.

[0047] The connection and geometry of the support element 110 allow it to buckle or roll backwards in the longitudinal direction X of the vehicle, which in turn enables the deformation element 108 to fold almost completely in the event of a crash. Furthermore, due to its position and / or geometry, no other components of the vehicle, such as a radiator, are damaged when the support element 110 buckles or rolls.

[0048] As can be seen in particular from Fig. 5, the support element 110 also has a u-shaped profile, which has proven to be particularly advantageous with regard to increasing stiffness.

[0049] Similarly, the support element 110, as shown in Fig. 5, has a contact surface 114 on its underside that is larger than the cross-section on its upper side. The contact surface 114 serves as a "guiding shoe" for forces occurring when the vehicle briefly touches the road surface. The contact surface 114, together with the positioning of the support element 110 as described above, enables optimal force absorption while simultaneously adhering to the installation space requirements, thus protecting vehicle components, and in particular those located in the engine compartment, from vertical forces (forces in the vehicle's vertical direction Z) and therefore from damage.Furthermore, the pedestrian protection crossbeam 104 has a contact surface 116 extending in the transverse direction Y of the vehicle and in the vertical direction Z of the vehicle, which serves as a contact surface for a stop surface 118 of the support element 110 when the pedestrian protection crossbeam 104 is moved from front to back under the influence of force in the longitudinal direction X of the vehicle.

[0050] The features of the invention disclosed in the present description, the drawings, and the claims can be essential for realizing the invention in various embodiments, both individually and in any combination. The invention can be varied within the scope of the claims and taking into account the knowledge of the person skilled in the art.

[0051] Reference symbol

[0052] 100 motor vehicle front structure

[0053] 102 main crossbeams

[0054] 104 pedestrian protection crossbeams

[0055] 106 Connecting element

[0056] 108 Deformation element

[0057] 110 support element

[0058] 112 Bodywork element

[0059] 114 Mounting surface

[0060] 116 Contact surface of the pedestrian protection crossbeam

[0061] 118 Stop surface of the support element

[0062] D Detail section

[0063] X Vehicle longitudinal direction

[0064] Y Vehicle transverse direction

[0065] Z Vehicle lifting direction

Claims

Patent claims 1. Motor vehicle front structure (100) with a main cross member (102) extending in the transverse direction (Y) of the vehicle, a pedestrian protection cross member (104) arranged below it in the vertical direction (Z) of the vehicle, which is arranged on the main cross member (102) via at least one connecting element (106), characterized in that the motor vehicle front structure (100) has, in addition to the connecting element (106), a support element (110) which extends downwards in the vertical direction (Z) of the vehicle.

2. Motor vehicle front structure (100) according to the preceding claim, characterized in that the support element (110) is connected to a body element (112) at its upper side behind the connecting element (106) in the longitudinal direction (X) of the vehicle and extends forward and downward from the connecting point in the longitudinal direction (X) of the vehicle.

3. Motor vehicle front structure (100) according to one of the preceding claims, characterized in that the support element (110) is firmly connected to a deformation element (108) which is connected behind the main cross member (102) in the longitudinal direction (X) of the vehicle.

4. Motor vehicle front structure (100) according to one of the preceding claims, characterized in that the support element (110) extends downwards in the vehicle vertical direction (Z) at least to the same level or into a lower area than an assembly of the motor vehicle.

5. Motor vehicle front structure (100) according to one of the preceding claims, characterized in that the support element (110) has a contact surface (114) on its underside that is larger than the cross-section adjoining it on the top side.

6. Motor vehicle front structure (100) according to one of the preceding claims, characterized in that the support element (110) has a U-shaped profile in cross-section and / or at least one groove is formed in the support element (110).

7. Motor vehicle front structure (100) according to one of the preceding claims, characterized in that the connecting element (106) and the support element (110) are arranged next to each other when viewed in the transverse direction (Y) of the vehicle.

8. Motor vehicle front structure (100) according to one of claims 1-6, characterized in that the pedestrian protection cross member (104) has a complementary geometry to the support element (110).

9. Motor vehicle front structure (100) according to the preceding claim, characterized in that the pedestrian protection cross member (104) has a contact surface (116) extending in the transverse direction (Y) and in the vertical direction (Z) of the vehicle, which serves as a contact surface for a stop surface (118) of the support element (110) when the pedestrian protection cross member (104) is moved from front to rear under the influence of force in the longitudinal direction (X) of the vehicle.

10. Motor vehicle with a motor vehicle front structure (100) according to one of claims 1 to 9.

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