Curved side member, for a motor vehicle

Abstract

A longitudinal member (LV) is installed on a longitudinal side (CL) of a floor (PV) of a structure (SV) of a motor vehicle (VA), and has a continuously curved shape at least in an intermediate portion (PI) located between two opposing end portions (PE), defining a cavity (CAL) oriented towards a central portion (PCP) of the floor (PV), and allowing it to absorb a lateral impact sustained by the motor vehicle (VA) on that longitudinal side (CL). Figure 1

Description

Title of the invention: Curved side member for a motor vehicle Technical field of the invention

[0001] The invention relates to motor vehicles comprising a structure including a floor having two opposite longitudinal sides, and more specifically the side members which frame these two opposite longitudinal sides. State of the art

[0002] Many motor vehicles include a structure comprising a floor having right and left longitudinal sides and two (lateral) side members, right and left, installed respectively on these right and left longitudinal sides. These side members are generally straight, and in this case they are installed respectively parallel to the right and left longitudinal sides of the vehicle.

[0003] In order for the passengers of a vehicle to be well protected in the event of a side impact on one of its right and left longitudinal sides, it is essential that the side members absorb (or withstand) as much of the energy of this side impact as possible. Here, "side impact" is understood to mean an impact along a direction having a non-zero transverse component (the transverse direction being perpendicular to the longitudinal direction and therefore to the longitudinal sides).

[0004] It should be noted that the absorption (or absorption) capacity of the side members must be greater the greater the weight of the vehicle and the lateral impact results from a collision with an object of small longitudinal extension, such as a post.

[0005] It should also be noted that when the vehicle has a powertrain (or PWM) of the all-electric or hybrid (thermal and electric) type, it includes a set (or "pack") of rechargeable battery which can be installed between its side rails, under its floor and generally under at least one cross member, and therefore must also be protected in the event of a side impact, in particular for safety reasons.

[0006] In order for the side members to absorb as much of the energy as possible from a side impact, their width and height are significant, and therefore their weight is significant (typically greater than 16 kg). Consequently, the side members contribute to the vehicle's weight and thus reduce its driving range.

[0007] Furthermore, when one wants to increase the mileage range of a hybrid powertrain vehicle, one solution is to increase the energy storage capacity The electric motor of its rechargeable battery (main, traction, or power) increases its dimensions. Generally, this increase occurs along the vehicle's transverse direction, which necessitates a reduction in the width of the side members and therefore a decrease in their absorption (or load-bearing) capacity, even though they must also protect the rechargeable battery.

[0008] The invention therefore aims in particular to improve the situation. Presentation of the invention

[0009] In particular, it proposes for this purpose a longitudinal member suitable for installation on a longitudinal side of a floor of a structure of a motor vehicle.

[0010] This longitudinal member is characterized by the fact that it has a continuously curved shape at least in an intermediate part located between two opposite end parts, defining a cavity intended to be oriented towards a central part of the floor, and suitable for allowing the absorption of a lateral shock suffered by the motor vehicle on the longitudinal side concerned.

[0011] Thanks to this continuously curved shape at least in the intermediate part combined with the specific orientation of the cavity, the capacity to absorb (or withstand) the energy of a lateral shock of the longeron can be advantageously reinforced.

[0012] The longeron according to the invention may include other features which may be taken separately or in combination, and in particular:

[0013] - its continuously curved shape can correspond to a fixed radius of curvature;

[0014] - the cavity can have a maximum extension, along a direction intended to be perpendicular to the longitudinal side, between 3 cm and 6 cm;

[0015] - in the presence of the last option, the maximum extension can be equal to 4 cm;

[0016] - it may have a width, along a direction which is intended to be perpendicular dicular on the longitudinal side, which is strictly less than the width of a straight side member (of a vehicle of the prior art) suitable to allow at most the absorption of lateral shock (mentioned above);

[0017] - in the presence of the last option, the width can be reduced by a value between between 3 cm and 6 cm;

[0018] - in the presence of the last sub-option, the width can be reduced by a value equal to 4 cm;

[0019] - it may comprise a main profile having the continuously curved shape and comprising opposing internal and external curved edges and between which internal boxes are defined.

[0020] The invention also proposes a motor vehicle comprising a structure including a floor having right and left longitudinal sides and two right and left longitudinal members of the type shown above and installed resp- tively on these longitudinal right and left sides.

[0021] For example, this motor vehicle may also include a rechargeable battery pack installed under the floor between the right and left side members. Brief description of the figures

[0022] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings (obtained using CAD / CAM (“Computer-Aided Design / Computer-Aided Manufacturing”)), in which:

[0023] [Fig. 1] schematically illustrates, in a bottom view, an example of a motor vehicle comprising early examples of the embodiment of longitudinal members according to the invention framing a rechargeable battery assembly,

[0024] [Fig.2] schematically illustrates, in a perspective view from below and from the side, a rear left part of a rechargeable battery assembly next to which is placed a second example of a longitudinal member embodiment according to the invention, and

[0025] [Fig.3] schematically illustrates, in a bottom view, the left side member of the [Fig.2], Detailed description of the invention

[0026] The invention aims in particular to provide an LV side member intended to be part of an SV structure of a motor vehicle VA and having an absorption (or energy-absorbing) capacity for a lateral impact and / or a reduced mass.

[0027] It is recalled that here we mean "lateral impact" an impact suffered by the motor vehicle VA on a longitudinal side CL and therefore taking place in a direction having a non-zero transverse component (in the transverse direction Y of the motor vehicle VA).

[0028] In what follows, the motor vehicle VA is considered, by way of non-limiting example, to be a car. However, the invention is not limited to this type of motor vehicle. It relates in fact to any motor vehicle comprising a structure including a floor (incorporating optional crossmember(s)) framed by two longitudinal members.

[0029] In figures 1 to 3, direction X is the longitudinal direction of the vehicle (automobile) VA, which is substantially parallel to the longitudinal (or lateral) sides comprising the side doors, direction Y is the transverse direction of the vehicle VA, which is perpendicular to the longitudinal direction X, and direction Z is the vertical direction of the vehicle VA, which is perpendicular to the longitudinal direction X and transverse direction Y.

[0030] Figure [1] schematically illustrates an example of a vehicle (automobile) VA comprising early examples of the realization of LV longitudinal members, right and left, according to the invention. Although it appears only partially on [Fig.1], the SV structure includes in particular a PV floor having right and left longitudinal sides CL, and two LV stringers, right and left, installed respectively on these right and left longitudinal sides CL.

[0031] It should be noted that in the example illustrated, but not limited to, in [Fig. 1], the vehicle VA also includes a rechargeable battery pack EB installed under the floor PV between the right and left side members LV. However, this is not mandatory, as the invention also applies when the vehicle VA does not have a rechargeable battery pack EB.

[0032] For example, the rechargeable battery of this EB assembly may be of the cellular type. In this case, its rechargeable cellular battery comprises electrical energy storage cells, possibly electrochemical (for example, lithium-ion (or Li-ion) or Ni-MH or Ni-Cd type). Also, for example, such a rechargeable cellular battery may be of the low or medium voltage type (typically 450 V).

[0033] As illustrated at least partially in Figures 1 to 3, a longitudinal member LV, according to the invention, has a continuously curved shape at least in an intermediate portion PI located between its two opposing end portions PE. This curved shape defines a cavity CAL intended to be oriented towards the central portion PCP of the floor PV. Consequently, once the two longitudinal members are installed on the two longitudinal sides CL of the structure SV, the cavities CAL that they define are oriented towards each other.

[0034] Moreover, this curved shape is suitable for allowing the absorption of a lateral shock suffered by the vehicle VA on the longitudinal side CL concerned, including in a direction which is substantially perpendicular to the latter (CL).

[0035] This continuously curved shape, at least in the intermediate section PI (which includes the central part of the LV side member), combined with the specific orientation of the CAL cavity (opposite to where an impact may occur), advantageously makes it possible to significantly enhance the energy absorption (or assimilation) capacity of this LV side member in a lateral impact, including when this lateral impact results from a collision with an object of small longitudinal extent, such as a post PT (see [Fig. 3]). Consequently, the invention makes it possible, at the very least, to enhance the passive safety of the vehicle VA.

[0036] For example, and as illustrated, but not limited to, in [Fig. 1], the continuously curved shape may correspond to a fixed radius of curvature. However, it could be envisaged that the radius of curvature of the curved portion varies at least slightly.

[0037] It should be noted that in the first example illustrated, but not limited to, in [Fig. 1], the entirety of each LV longeron has a continuously curved shape (in other In terms of the middle section, the intermediate part PI and the end sections PE (which frame the intermediate part PI) are continuously curved. But in the second example, illustrated non-exhaustively in Figures 2 and 3, the intermediate part PI has a continuously curved shape and the end sections PE (which frame the intermediate part PI) are not curved (they are essentially "straight" in line with the intermediate part PI).

[0038] Also, for example, the cavity CAL can have a maximum extension, along a direction intended to be perpendicular to the longitudinal side CL (here the transverse direction Y), of between 3 cm and 6 cm. As an illustrative example, this maximum extension can be equal to 4 cm. But other values ​​of maximum extension can be used. For example, the value of the maximum extension can be determined during a development phase of a vehicle similar to vehicle V. It will be understood that the greater the value of the maximum extension, the greater the capacity of the LV to absorb (or withstand) the energy of a lateral impact, but the greater its transverse bulk (here along the transverse direction Y) will be.

[0039] Also, for example, the LV side member may have a width, along a direction intended to be perpendicular to the longitudinal side CL (here the transverse direction Y), that is strictly less than the width of a straight side member suitable for allowing at most the same impact absorption as the LV side member in a prior art motor vehicle. This reduction in width is particularly advantageous because it makes it possible to significantly reduce the weight of each LV side member while the energy absorption (or impact absorption) capacity of the LV side member remains the same as, or even slightly greater than, that obtained with a straight side member of unreduced width from the prior art.

[0040] For example, the width of the LV side member can be reduced by a value between 3 cm and 6 cm. As an illustrative example, this width reduction could be 4 cm. However, other width reduction values ​​can be used. For example, the width reduction value can be determined during the development phase of a vehicle similar to vehicle V. It will be understood that the greater the width reduction value, the less the LV side member's capacity to absorb (or withstand) the energy of a lateral impact will be, but the less its transverse bulk (here along the transverse Y direction) will be (for the same curvature).

[0041] Also, for example, and as illustrated non-limitingly in [Fig.2], the LV spar may comprise a main profile PP having a continuously curved shape (at least in its intermediate part PI), and having opposing internal curved edges BCI and external curved edges BCE and between which box sections are defined Internal CI (extending here substantially along the longitudinal X direction but with bending). Also, for example, the main PP profile can be made of aluminum. But it could also be made of steel.

[0042] As illustrated, the inner longitudinal edge BLI is intended to be oriented towards the PV floor and the possible rechargeable battery assembly EB, and the outer longitudinal edge BLE is opposite the inner longitudinal edge BLI and therefore intended to be oriented towards the outside of the vehicle VA. It should be noted that the main profile PP also includes an upper longitudinal edge, connecting the outer longitudinal edges BLE and the inner longitudinal edge BLI, and a lower longitudinal edge, connecting the outer longitudinal edges BLE and the inner longitudinal edge BLI but opposite the upper longitudinal edge BLS.

[0043] The respective shapes and arrangements of the internal boxes CI are chosen so that the LV spar, and more specifically its main profile PP, offers a programmed deformation kinematic, possibly progressive, which allows a substantially predefined distribution of the forces which are transferred to the PV floor and to the possible rechargeable battery assembly EB (the majority of the forces going to the PV floor to protect, here, the rechargeable battery assembly EB).

[0044] Also, for example, the internal walls that at least partially delimit the internal compartments CI and / or the inner longitudinal edges BLI, outer longitudinal edges BLE, upper and lower edges can have a thickness of between 1.5 mm and 8 mm. Preferably, their thicknesses can be between 2 mm and 7 mm.

[0045] It should also be noted that the LV spar could also comprise a casing made up of two metal half-shells fixedly joined to each other and housing the main PP profile. For example, these two metal half-shells of the casing can be made of steel or aluminum.

Claims

Claims

1. Side member (LV) suitable for being installed on a longitudinal side (CL) of a floor (PV) of a structure (SV) of a motor vehicle (VA), characterized in that it has a continuously curved shape at least in an intermediate part (PI) located between two opposite end parts (PE), defining a cavity (CAL) intended to be oriented towards a central part (PCP) of said floor (PV), and suitable for allowing absorption of a lateral impact suffered by said motor vehicle (VA) on said longitudinal side (CL).

2. A spar according to claim 1, characterized in that said continuously curved shape corresponds to a fixed radius of curvature.

3. Longeron according to claim 1 or 2, characterized in that said cavity (CAL) has a maximum extension, in a direction intended to be perpendicular to said longitudinal side (CL), of between 3 cm and 6 cm.

4. A spar according to claim 3, characterized in that said maximum extension is equal to 4 cm.

5. Longeron according to one of claims 1 to 4, characterized in that it comprises a main profile (PP) having said continuously curved shape and comprising opposite inner (BCI) and outer (BCE) curved edges and between which internal boxes (CI) are defined.

6. Motor vehicle (VA) comprising a structure (SV) comprising a floor (PV) having right and left longitudinal sides (CL), characterized in that said structure (SV) further comprises two side members (LV), right and left, according to one of the preceding claims, installed respectively on said right and left longitudinal sides (CL).

7. Motor vehicle according to claim 6, characterized in that it comprises a rechargeable battery assembly (EB) installed under said floor (PV) between said right and left side members (LV).

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