Vehicle structure with reduced seat crossmember reinforcements.

Abstract

The invention relates to a motor vehicle chassis structure (1) comprising at least one cross member (2) extending between two lateral side members (3) of the structure (1), each cross member (2) being disposed on a floor (4) of the structure (1), the chassis structure (1) comprising at least one cross member reinforcement (6), each fixed to the floor (4), below the latter and aligned with a cross member (2), each cross member reinforcement (6) being designed to reinforce at least part of the floor (4) and extending from a lateral edge (8) of the floor (4) along a cross member (2) for a length (L) less than 25% of the distance (D) between the two lateral side members (3). (Figure 1)

Description

Title of the invention: Vehicle structure with reduced seat crossmember reinforcements.

[0001] The technical field relates to vehicle chassis structures having seat crossmember reinforcements and vehicles having such structures.

[0002] In terms of road safety, car manufacturers must consider numerous concerns and regulations when developing new vehicles. Thus, car manufacturers must ensure the safety of vehicle occupants in the event of a collision, but also protect other vulnerable road users such as pedestrians. To guarantee passenger safety, vehicles undergo various crash simulation procedures, including impacts against a rigid pole striking the vehicle from the side, at the level of the passenger doors, known as a side impact against a pole. In a side impact against a pole, the deformations experienced by the vehicle floor are specifically studied to minimize the pole's intrusion into the protected space around the passengers.

[0003] To meet the aforementioned requirements, motor vehicle manufacturers have developed body designs capable of distributing the deformation forces resulting from a lateral impact against a pole along the entire length of the body in order to protect the passenger compartment. The solutions developed involve installing stiffening elements designed to transfer at least a portion of the forces originating from a point of impact on the pole, thereby transmitting the deformation forces along the entire length of the body. In the specific case of a lateral impact against a pole, the stiffening elements are generally arranged on a floor, opposite cross members that extend transversely between the vehicle's frame members. These stiffening elements thus reinforce the structure and the weld points of the various assemblies.

[0004] Such a reinforced body architecture is quite capable of dissipating the energy of an impact and controlling the deformation of the body architecture for most internal combustion engine vehicles. However, automakers are developing their electric vehicle offerings and, to this end, are adapting their existing internal combustion engine vehicles to create suitable electric versions. Such adaptation generally involves a substantial increase in the total vehicle mass due to the additional equipment, particularly the mass of the battery. An increase in mass translates into an increase in the quantity energy to be dissipated in the event of a collision. However, without reinforcing the body structure, the behavior of an adapted electric version can fundamentally alter the behavior of the internal combustion engine version and, in particular, may no longer meet certification test requirements. This then creates an increased risk of endangering vehicle occupants through intrusion into the passenger compartment. Therefore, to guarantee equivalent passive safety after converting an internal combustion engine vehicle to an electric vehicle, it is necessary to find a solution that strengthens the structure without significantly increasing its mass.

[0005] Furthermore, electric vehicles present risks of their own, related to the risks of runaway and ignition of the batteries if they are impacted during a shock.

[0006] Thus, there is a need for a solution that guarantees the safety of passengers and batteries while reducing the mass of chassis structures.

[0007] The present invention aims to overcome the problems described above. In this technical context, one objective of the present invention is to provide a chassis structure with reinforcements capable of ensuring sufficient resistance to deformation while reducing the overall mass of the structure.

[0008] To this end, the present invention relates to a motor vehicle chassis structure comprising at least one seat cross member extending between two lateral side members of the structure, each seat cross member being disposed on a floor of the structure, the chassis structure comprising at least one cross member reinforcement, each attached to the floor, below the latter and opposite a seat cross member, each cross member reinforcement being designed to reinforce at least part of the floor and extending from a lateral edge of the floor along a seat cross member for a length less than 25% of the distance between the two lateral side members.

[0009] The invention finally relates to a motor vehicle having a structure according to the invention.

[0010] Thus, the chassis structure according to the invention, thanks to each crossmember reinforcement, exhibits resistance to deformation during a side impact against a post, ensuring passenger safety by limiting the intrusion of bodywork elements into the passenger compartment. Since the length over which the reinforcement extends is limited to 25% of the distance between the two side members, the mass of the crossmember reinforcements is limited. Therefore, the chassis structure according to the invention ensures passenger safety while limiting the mass of the reinforcements, in this case, the mass of the crossmember reinforcements.

[0011] According to one embodiment of the invention, the structure has a cross brace arranged at each end of each seat cross brace.

[0012] According to one possibility, each cross brace extends over a length less than 15% of the distance between the two side rails.

[0013] According to one embodiment, at least a portion of each cross member reinforcement extends between the floor and a longitudinal member, in front of and behind the corresponding seat cross member.

[0014] Advantageously, each cross brace extends on either side of a longitudinal member over substantially equal lengths.

[0015] According to one possibility, a traction battery is disposed under the floor.

[0016] The invention will be better understood upon reading the following detailed description, given solely by way of non-limiting example and made with reference to the accompanying drawing in which:

[0017] [Fig-1] [Fig.1] represents a perspective and bottom view of a structure of chassis of a vehicle according to the invention showing four crossmember reinforcements.

[0018] A chassis structure 1, illustrated in [Fig. 1], is designed to equip a motor vehicle according to the invention. The structure 1 comprises at least one seat crossmember 2, in this case two seat crossmembers 2, shown as dashed lines in the figures, each extending between two lateral side members 3 of the structure 1, illustrated in [Fig. 1]. To facilitate the illustration of the structure 1 according to the invention, a portion of one of the two side members 3 has been omitted from the figure. Each seat crossmember 2 is arranged on a floor 4 of the structure 1.

[0019] The floor 4 has an upper face, hidden in the figure, facing the vehicle's passenger compartment, and a lower face 5, visible in the figure and facing a road on which the vehicle according to the invention travels. With respect to the floor 4, "on" and "above" refer to the upper face, while "under" and "below" refer to the lower face 5. In this case, each seat cross member 2 is located on the upper face of the floor 4.

[0020] As illustrated in the figure, the chassis structure 1 further comprises at least one cross member 6, each fixed to the floor 4, below the latter and aligned with a seat cross member 2. As illustrated in the figure, the structure 1 has two seat cross members 2 and a cross member 6 is located at each end 7 of each cross member 2.

[0021] Each cross member 6 is designed to reinforce at least partially the floor 4 at the cross member 2. Each cross member 6 extends from a lateral edge 8 of the floor 4 along a seat cross member 2 for a length less than 25% of the distance D, illustrated in the figure, between the two lateral stringers 3. Preferably, each reinforcement 6 extends along a cross member 2 over a length less than 15% of the distance D between the two lateral stringers 3.

[0022] Each cross member reinforcement 6 is formed, for example, from a stamped sheet metal. The attachment of a cross member reinforcement 6 to the floor 4 is, for example, achieved by welding.

[0023] Advantageously, as illustrated in [Fig.1], at least a part 9 of each cross brace 6 extends between the floor 4 and a longitudinal member 3, in front and behind the corresponding seat cross member 2.

[0024] Each cross brace 6 extends on either side of a longitudinal member 3 over lengths, illustrated in the figure, that are substantially equal.

[0025] Finally, according to one possibility of the invention, the structure 1 has a traction battery, not illustrated, arranged under the floor 4.

[0026] Thus, as the simulations have shown, the structure 1 according to the invention ensures the safety of the vehicle's passengers by limiting intrusive deformations in the vehicle's passenger compartment during a side impact against a pole. The crossmember reinforcements 6 thus provide adequate reinforcement while reducing mass compared to conventional solutions. The mass savings achieved by the crossmember reinforcements 6 represent, for example, up to 60% of the mass of a conventional reinforcement and a mass saving of approximately 10 kg compared to a conventional vehicle body.

[0027] The invention is not limited to the embodiment of the chassis structure described above, only by way of example, but other embodiments can be designed by a person skilled in the art without departing from the scope and extent of the present invention.

Claims

Demands

1. Motor vehicle chassis structure (1) comprising at least one cross member (2) extending between two lateral side members (3) of the structure (1), each cross member (2) being disposed on a floor (4) of the structure (1), the chassis structure (1) comprising at least one cross member reinforcement (6), each attached to the floor (4), below the latter and opposite a cross member (2), each cross member reinforcement (6) being designed to reinforce at least part of the floor (4) and extending from a lateral edge (8) of the floor (4) along a cross member (2) for a length (L) less than 25% of the distance (D) between the two lateral side members (3), wherein at least a portion (9) of each cross member reinforcement (6) extends between the floor (4) and a side member (3), in front of and behind the cross member (2) corresponding seating,and in that each cross brace (6) extends on either side of a longitudinal member (3) over substantially equal lengths.

2. Chassis structure (1) according to claim 1, characterized in that the structure (1) has a cross brace (6) arranged at each end (7) of each seat cross brace (2).

3. Chassis structure (1) according to claim 1 or 2, characterized in that each cross member reinforcement (6) extends over a length (L) less than 15% of the distance (D) between the two lateral side members (3).

4. Chassis structure (1) according to any one of claims 1 to 3, characterized in that a traction battery is arranged under the floor (4).

5. Motor vehicle having a structure (1) according to any one of claims 1 to 4.

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