FRONT CROSSMEMBER MOUNTING FOR CRASH TEST "SMALL OVERLAP"

Abstract

FRONT CRASH BEAM ASSEMBLY FOR "SMALL OVERLAP" CRASH TEST The invention relates to a motor vehicle (2) comprising two longitudinal profiles (4) extending forward from a passenger compartment portion of the motor vehicle; a front crossmember (12); the front crossmember (12) comprising means for temporarily supporting, during assembly, a structural crossmember (10) intended to connect the two longitudinal profiles (4). (Figure to be published with the abbreviation: Figure 2)

Description

Title of the invention: FRONT CROSSMEMBER MOUNTING FOR "SMALL OVERLAP" CRASH TEST technical field

[0001] The invention relates to the field of motor vehicles, in particular to the field of motor vehicle structures and their ability to successfully undergo impact tests, in particular frontal impact tests. Previous technique

[0002] A series of impact tests, or "crash tests," with standardized and recognized procedures exist for evaluating the passive safety of motor vehicles. In particular, there are impact tests specific to the U.S. market, designated the "driver side small overlap front test" and the "passenger side small overlap front test," developed by the Insurance Institute for Highway Safety (IIHS). The IIHS is an independent, non-profit scientific and educational organization dedicated to reducing losses from motor vehicle accidents due to death, injury, and property damage. This test is designed to replicate what happens when the front left corner of a vehicle collides with another vehicle or an object such as a tree or pole. This crash test poses a challenge to certain seat belt and airbag designs because the occupants move both forward and sideways within the vehicle.In the driver's side small overlap frontal impact test, a vehicle travels at 64 km / h toward a rigid barrier 150 cm high. A crash test dummy representing an average-sized man is placed in the driver's seat. Twenty-five percent of the vehicle's total width strikes the barrier on the driver's side. Most modern cars have roll cages encapsulating the passenger compartment and designed to withstand frontal and moderate overlap frontal impacts with minimal deformation. At the same time, crash zones help manage collision energy to reduce forces on the passenger compartment. The main structures of the crash zone are concentrated in the mid-section of the front end. When a crash involves these structures, the passenger compartment is protected from intrusion, and the front airbags and seat belts can effectively restrain and protect the occupants.Small overlap frontal collisions primarily affect the outer edges of a vehicle, which are not well protected by the structures in the crush zone. The collision forces are transmitted directly to the front wheel, the suspension system, and the front bulkhead. It is not uncommon for the wheel to be forced rearward into the floor, contributing to further intrusion into the passenger compartment and resulting in [further damage / damage]. Serious leg and foot injuries. To provide effective protection in minor collisions, the safety cage must withstand impact forces that are not mitigated by the structures in the impact zone. For this purpose, a structural crossmember located at the front end and attached directly to the ends of the front struts is a known solution. This crossmember is structural in that it possesses a certain rigidity and mass, and consequently a significant weight, for example, at least 10 kg. Such mass inevitably poses ergonomic problems during assembly.

[0003] Published patent document FR 3 031 952 A1 discloses a front fascia module comprising a front fascia crossmember and two side members configured for easy assembly with said front fascia crossmember, in this case by means of an insert connection system. This front fascia module thus has a reduced volume in its unassembled state and can be easily assembled while maintaining sufficient rigidity. However, this fascia module is limited to supporting various elements such as the engine cooling radiator, headlights, and the front hood latch. It does not provide a rigid connection between the two crossmembers like the aforementioned structural crossmember. This document therefore fails to provide a solution to the aforementioned problem. Description of the invention

[0004] The invention aims to overcome at least one of the drawbacks of the aforementioned prior art. More specifically, the invention aims to facilitate the mounting of a structural crossmember at the front of a motor vehicle, the crossmember in question being intended to be fixed to the two longitudinal profiles or frame members of the vehicle structure.

[0005] The invention relates to a motor vehicle comprising two longitudinal profiles extending forward from a passenger compartment part of the motor vehicle; a front front cross member; notable in that the front front cross member includes means for providing temporary support, during assembly, for a structural cross member intended to connect the two longitudinal profiles.

[0006] According to an advantageous embodiment of the invention, the temporary support means comprise at least two hooks projecting forward.

[0007] According to an advantageous embodiment of the invention, the front facade cross member is made of plastic material, the temporary support means being integrally formed with said front facade cross member.

[0008] According to an advantageous embodiment of the invention, the temporary support means are configured to support a central portion of the structural cross member.

[0009] Advantageously, the central portion of the structural cross member is transverse and straight.

[0010] According to an advantageous embodiment of the invention, the motor vehicle comprises the structural crossmember, said structural crossmember having an inverted U-shape and comprising a central portion opposite the front face of the front fascia crossmember; and two lateral portions extending downwards from two ends of the central portion and fixed to the two longitudinal profiles, respectively.

[0011] According to an advantageous embodiment of the invention, each of the two lateral portions of the structural cross member comprises a plate fixed by screwing to a plate of the corresponding longitudinal profile.

[0012] According to an advantageous embodiment of the invention, each of the two lateral portions forms a hollow body with a cross-section decreasing towards the central portion of the structural cross member.

[0013] According to an advantageous embodiment of the invention, the at least two hooks are configured to extend under and in front of the central portion of the structural cross member or to fit into openings formed in an underside face of said central portion.

[0014] The invention also relates to a front fascia crossmember for a motor vehicle, comprising a main longitudinal portion with two opposite ends; means for fixing to the opposite ends of the main longitudinal portion; notable in that the front fascia crossmember further comprises at least two hooks on a front face of the main longitudinal portion.

[0015] The characteristics stated in relation to the motor vehicle apply to the front front crossmember and vice versa.

[0016] The at least two hooks advantageously form a support direction parallel to the direction of the main longitudinal portion. The at least two hooks are advantageously configured to support a straight portion of a structural cross member. The at least two hooks are advantageously configured to support a total load of at least 10 kg.

[0017] The invention also relates to a method for assembling a motor vehicle, comprising the following steps: (a) mounting a front fascia crossmember; (b) mounting a structural crossmember in front of the front fascia crossmember; notable in that the vehicle is according to the invention; and step (b) includes a provisional positioning of the structural crossmember on the provisional support means of the front fascia crossmember, and then a fixing of the structural crossmember to the two longitudinal profiles.

[0018] The measures of the invention are interesting in that they facilitate the assembly of the structural crossmember by providing temporary support in the mounting position. The assembly of the structural crossmember is, in fact, subsequent, temporally, to the assembly of the front facade crossmember, meaning that the latter is present at the time of the structural crossmember's assembly. Also, the structural crossmember is positioned in front of the front facade crossmember. The invention thus takes advantage of the front facade crossmember to facilitate the assembly of a potentially heavy component that, moreover, cannot be placed on any adjacent support surface, other than the temporary support means according to the invention.Positioning the lateral portions of the structural cross member opposite the front ends of the longitudinal profiles requires precise positioning in a transverse vertical plane, i.e. along the y and z axes in an orthonormal coordinate system where the x axis is a longitudinal axis, the y axis a horizontal transverse axis and the z axis a vertical axis; then positioning along the x axis can be finalized during fixing, for example when fixing deformable boxes ("crashboxes") in the forward extension of the longitudinal profiles. Brief description of the drawings

[0019] [Fig-1] is a perspective representation of the front part of the structure of a motor vehicle according to the invention;

[0020] [Fig.2] is a detailed view of the front of the motor vehicle of [Fig.1];

[0021] [Fig.3] represents a front facade cross member allowing provisional support evening, during assembly, the structural cross member, according to a first embodiment of the invention;

[0022] [Fig.4] represents a front facade cross member allowing provisional support evening, during assembly, the structural cross member, according to a second embodiment of the invention. Detailed description

[0023] Fig. 1 illustrates the front home of a motor vehicle structure according to the invention.

[0024] The motor vehicle 2 has two longitudinal profiles 4 extending forward from the passenger compartment of the motor vehicle, under the floor of said vehicle, these longitudinal profiles being commonly referred to as stretchers, by analogy with the arms of a stretcher. A front bumper crossmember 6 is attached to the front ends of the longitudinal profiles 4 via two deformable compression boxes 8, commonly referred to by the Anglo-Saxon term "crashboxes".

[0025] The motor vehicle 2 is characterized by a structural cross member 10 mechanically connecting the ends of the two longitudinal profiles 4. The structural cross member 10 has a general inverted U-shape, with a central portion forming a transverse profile and two lateral portions rigidly connected to the central portion and fixed to the ends of the two longitudinal profiles 4. Each The two lateral sections can form a hollow body with a cross-section that decreases towards the central section. This crossmember is structural in that it is massive and provides substantial reinforcement to the vehicle's structure. This reinforcement is intended to make the vehicle compatible with the small overlap crash test developed for the American market and mentioned earlier in the 'Previous Technology' section. In this crash test, the overlap between the obstacle and the front of the vehicle is so small that the obstacle avoids the longitudinal profile or crossmember located on the side of the obstacle. Therefore, the bumper crossmember 8, the front wheel (not shown), and the front reinforcement 11 will work to absorb the impact. As a result, the corresponding transverse profile 4 or crossmember tends to collapse, that is, to deform laterally towards the center of the vehicle.Structural crossmember 10 contains, at the very least, this tendency and allows the motor vehicle to achieve a satisfactory score in the aforementioned test.

[0026] Figure 2 is a more detailed view of the front end of the motor vehicle of Figure 1. In this view, the front bumper crossmember and the deformable boxes illustrated in Figure 1 are not shown. The structural crossmember 10 is clearly visible, in particular the generally straight and transverse central portion 10.1, and the two lateral portions 10.2 extending downwards from the ends of the central portion 10.1 and attached to the front ends of the two longitudinal profiles (not shown). Figure 2 shows the presence of a front end crossmember 12 directly behind the structural crossmember 10. The front end crossmember 12 is attached at its ends to the fender liners (not shown) and serves as a support, in particular, for the internal combustion engine's cooling radiator and / or the air conditioning system's heat exchanger, the headlights, and / or the front hood latch, in a manner known per se.

[0027] According to the invention, the front fascia crossmember 12 is used as a temporary support for the structural crossmember 10 during its mounting on the motor vehicle. With reference to the description of the structural crossmember 10 in relation to [Fig. 1], it has a certain mass, typically a weight of at least 10 kg. It is therefore particularly useful to be able to support it temporarily in the mounting position. Temporary support means are provided on the front fascia crossmember 12, advantageously on the front face of the front fascia crossmember 12, designed to support the central portion 10.1 of the structural crossmember 10. The lateral portions 10.2 of the structural crossmember 10 can thus be fixed to the front ends of the longitudinal profiles.

[0028] It can be seen in [Fig. 2] that each of the lateral portions 10.2 has a plate fixed against a plate (not visible) at the front end of the longitudinal profile cor corresponding, by means of fixing screws through the fixing holes. Deformable boxes, as illustrated in [Fig.1], can then be fixed against the lateral portions 10.2 in the extension of the longitudinal profiles, in order to support the front bumper crossmember, as illustrated in [Fig.1].

[0029] Figure 3 illustrates a front facade cross member allowing temporary support, during assembly, of the structural cross member, according to a first embodiment of the invention.

[0030] The front fascia crossmember 12 comprises a main longitudinal portion 12.1 with two opposite ends, and fastening means 12.2 for said opposite ends. These fastening means 12.2 are, in this case, holes provided for attachment to the front fender liners and the front fenders. The front fascia crossmember 12 further comprises two hooks 12.3 projecting forward and configured to support the structural crossmember 10. The two hooks 12.3 are advantageously located on the front face of the main longitudinal portion 12.1 of the front fascia crossmember 12. In this case, each of the two hooks 12.3 has an L-shaped longitudinal cross-section, that is, with a generally horizontal portion projecting forward from the front fascia crossmember 12 and supporting an underside of the central portion 10.1 of the structural cross member 10, and a generally vertical portion extending upwards in front of the central portion 10.1 of the structural cross member 10.

[0031] Figure 4 illustrates a front facade crossmember for temporarily supporting the structural crossmember during assembly, according to a second embodiment of the invention. The reference numbers of the first embodiment are used to designate identical or corresponding elements of the second embodiment, these numbers being increased by 100. Reference is also made to the description of these elements in the first embodiment.

[0032] The second embodiment differs from the first embodiment in that the hooks 112.3 do not extend essentially vertically in front of the central portion 110.1 of the structural cross member 110 but rather in holes made in said central portion 110.1. These holes are made in an underside face of the central portion 110.1 of the structural cross member 110.

[0033] This configuration of the means of temporary support of the structural cross member is interesting in that these means, namely the hooks 112.3, do not extend to the front of the structural cross member 110, in particular its central portion 110.1, so as not to interfere with the elements of the motor vehicle located at the front of the structural cross member 110 and likely to move towards the cross member in question.

[0034] It can be observed that the structural cross members 10 and 110 illustrated in Figures 3 and 4 are somewhat different from that illustrated in Figures 1 and 2. This does not change however nothing to the principle of the invention and shows moreover that the invention is compatible with different embodiments of structural crossbeam.

[0035] The two embodiments of the temporary support means for the structural cross member during assembly, described above, illustrate the invention in a non-limiting manner, it being understood that other embodiments are conceivable. By way of example, these temporary support means may comprise a single hook or more than two hooks. They may also be removable, that is, capable of being removed after the structural cross member has been assembled and / or specifically installed before the structural cross member is assembled.

[0036] Generally, the front facade crossmember can be made of plastic, by injection molding. For this purpose, the temporary support means are advantageously made as a single unit with the front facade crossmember. Alternatively, however, they can be attached to the front facade crossmember.

Claims

Claims

1. Motor vehicle (2) comprising: - two longitudinal profiles (4) extending forward from a passenger compartment part of the motor vehicle; - a front fascia cross member (12); the front fascia cross member (12; 112) comprising temporary support means (12.3; 112.3), during assembly, of a structural cross member (10; 110) intended to connect the two longitudinal profiles (4), characterized in that the motor vehicle comprises the structural cross member (10; 110), said structural cross member having an inverted U shape and comprising: - a central portion (10.1; 110.1) facing the front fascia cross member (12; 112); - two lateral portions (10.2; 110.2) extending downwards from two ends of the central portion (10.1; 110.1) and fixed to the two longitudinal profiles (4), respectively.

2. Motor vehicle (2) according to claim 1, characterized in that the temporary support means comprise at least two hooks (12.3; 112.3) projecting forwards.

3. Motor vehicle (2) according to one of claims 1 and 2, characterized in that the front facade crossmember (12; 112) is made of plastic material, the temporary support means (12.3; 112.3) being integrally formed with said front facade crossmember.

4. Motor vehicle (2) according to one of claims 1 to 3, characterized in that the temporary support means (12.3; 112.3) are configured to support a central portion (10.1; 110.1) of the structural crossmember (10; 110).

5. Motor vehicle (2) according to one of the preceding claims, characterized in that each of the two lateral portions (10.2; 110.2) of the structural crossmember (10; 110) comprises a plate fixed by screwing to a plate of the corresponding longitudinal profile (4).

6. Motor vehicle (2) according to one of the preceding claims, characterized in that each of the two lateral portions (10.2; 110.2) forms a hollow body with a cross-section decreasing towards the central portion (10.1; 110.1) of the structural cross-member (10; 110).

7. Motor vehicle (2) according to one of claims 3 to 6 taken as dependent on claim 2, characterized in that the at least two hooks (12.3; 112.3) are configured to extend under and in front of the central portion (10.1) of the structural cross member (10; 110) or to fit into openings formed in a lower face of said central portion (110.1).

8. A method of assembling a motor vehicle (2), comprising the following steps: (a) mounting a front fascia crossmember (12; 112); (b) mounting a structural crossmember (10; 110) in front of the front fascia crossmember (12; 112); characterized in that the motor vehicle (2) is according to one of claims 1 to 7; and step (b) comprises a temporary positioning of the structural crossmember (10.1; 110.1) on the temporary support means (12.3; 112.3) of the front fascia crossmember (12; 112), and then a fixing of the structural crossmember (10; 110) to the two longitudinal profiles (4).

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