WO2024018122A1 - Body subframe for hybrid or electric vehicle equipped with reinforced lateral spars - Google Patents

Abstract

The invention relates to a body subframe (2) for a hybrid or electric motor vehicle, comprising a floor (3) extending transversely between two subframe lateral spars (10), and at least one seat crossmember (8, 9) fixed to the top of said floor and extending transversely between said two lateral spars, to which it is fixed; each lateral spar comprising an elongate hollow body of closed cross section composed of an internal spar part (12) and an external spar part which are fixed to each other, each lateral spar also comprising an inner reinforcement extending longitudinally along and inside its hollow body; characterized in that each lateral spar additionally comprises an outer reinforcement (15) fixedly attached against the outer face of a zone of said internal spar part situated opposite the at least one seat crossmember.

Description

Description

Title of the invention: Body base for hybrid or electric vehicle equipped with reinforced side rails

[Technical area]

[1] The present invention claims priority from French application 2207385 filed on July 19, 2022, the content of which (text, drawings and claims) is herein incorporated by reference. The present invention generally relates to the bodywork of hybrid or electric motor vehicles equipped with a propulsion battery. It is aimed in particular at such a body base provided with reinforced side rails.

[Prior art]

[2] A hybrid or electric type motor vehicle comprises, for its operation, an electric motor and possibly a combustion engine coupled to said electric motor. At least one propulsion battery is also provided in such a vehicle to power the electric motor.

[3] The body base of such a hybrid or electric vehicle conventionally comprises a front floor extending longitudinally between the front apron and the rear floor, and transversely between two side base members.

[4] Such a lateral underbody spar generally comprises an elongated hollow body of closed cross section and consisting of an internal spar part as well as an external spar part fixed to each other.

[5] The body base also includes at least one front seat crossmember fixed on top of the front floor and extending transversely between the two side base members under the first row of seats.

[6] The side underbody rails and the front seat crossmember(s) contribute to the rigidity of the body base and allow in the event of an impact lateral to effectively limit dynamic intrusions of the doors into the vehicle passenger compartment.

[7] Indeed, during the occurrence of such a lateral impact, a large part of the resulting forces pass through these elements which are dimensioned accordingly.

[8] During a lateral pole impact, and more particularly when this shock is caused at the level of a propulsion battery of a hybrid or electric vehicle, even slight depression of the corresponding side member caused by the crushing of the or seat crossmembers can lead to deformation of the propulsion battery and deterioration of some of its electrochemical cells, creating a risk of electrocution or chemical burns for passengers.

[9] In order to reduce the forces suffered by the seat crossmember(s) so as to limit the sinking of the spar during such a lateral impact, it is known in particular from document FR 3 081 418 A1, to accommodate, at inside the hollow body of each base side member, an interior reinforcement extending longitudinally along this hollow body.

[10] Such an interior reinforcement is designed to crash against the internal part of the hollow body of the spar so as to absorb a significant portion of the energy of the impact in order to limit the forces transmitted to the seat crossmember(s). .

[11] Unfortunately, the side impact test protocols show that this interior reinforcement only partially collapses due to the excessive deformation of the internal part of the hollow body of the spar caused by the corresponding end(s) of the seat crossbars.

[Disclosure of the invention]

[12] The present invention therefore aims to improve the situation.

[13] To this end, it proposes a body base for a hybrid or electric motor vehicle, comprising a floor extending transversely between two side base members as well as at least one seat crossmember fixed on the top of said floor and extending transversely between the two said side rails to which it is fixed; each said lateral spar comprising an elongated hollow body of closed cross section and consisting of an internal spar part as well as an external spar part fixed to each other, each said lateral spar also comprising an internal reinforcement s extending longitudinally along and inside its hollow body; characterized in that each said lateral spar further comprises an external reinforcement attached fixedly against the exterior face of a zone of said internal part of the spar located opposite said at least one seat crosspiece.

[14] The addition of such an external spar reinforcement makes it possible, in the event of a side impact, to limit the deformation of the internal part of the hollow body of the spar caused by the corresponding end(s) of the seat crossmember(s). , so as to optimize the crushing of the interior reinforcement against this internal part and to maximize the absorption of the energy of this shock by this interior reinforcement.

[15] The residual forces transmitted to the seat crossmember(s) are thus very significantly reduced, which makes it possible to considerably limit the crushing of this crossmember(s) and therefore the risk of deformation of the vehicle's propulsion battery.

[16] Furthermore, the fact that this external reinforcement extends only over a zone of the internal part of the spar makes it possible to limit the increase in mass of the lateral spar. The invention also makes it possible to maintain the same part reference for the internal and external spar parts of all versions of the same vehicle model equipped or not with a propulsion battery (the side spars of non-hybrid versions or electrical being devoid of interior and exterior reinforcements).

[17] According to preferred characteristics of said body base according to the invention:

- the internal part of each said lateral spar has a lying U-shaped profile in section and comprises a lateral core as well as two upper and lower flanges extending opposite to said floor from this lateral core, said exterior reinforcement of each said lateral spar having in section an inverted L-shaped profile and comprising a lateral wing placed against the exterior face of said lateral web as well as an upper wing extending opposite to said floor from this lateral core while being placed against the exterior face of said upper sole;

- each lateral end of said at least one seat crossmember is fixed to the corresponding lateral spar via tabs projecting transversely from said end and welded to the upper wing of the external reinforcement of this spar;

- the lateral wing of each said external reinforcement extends vertically on either side of said floor over at least most of the height of the lateral web of the internal part of the corresponding spar;

- the exterior reinforcement of each said lateral spar has cutouts made at certain respective zones of the internal part of this spar provided with fixing holes;

- the external reinforcement of each said lateral spar is obtained from a sheet of double-phase steel metal sheet having a thickness of between 1.5 and 2.5 millimeters;

- the internal reinforcement of each said lateral spar is constituted by a metal profile obtained by extrusion;

- the interior reinforcement of each said lateral spar has a cellular structure composed of an exterior envelope and a network of interior partitions crisscrossing the interior volume of this envelope; and or

- said base comprises two so-called seat crosspieces spaced longitudinally from one another.

[18] The invention also aims, in a second aspect, at a motor vehicle comprising such a body base.

[Brief description of the drawings]

[19] The presentation of the invention will now be continued with the detailed description of an exemplary embodiment, given below by way of illustration but not limitation, with reference to the appended drawings, in which:

- [Fig 1] represents a partial perspective view of a body structure of a hybrid or electric type vehicle comprising a body base according to the invention provided with two side rails bordering laterally a front floor;

- [Fig 2] is an exploded perspective view of one of the two side rails of the body base of Figure 1;

- [Fig 3] represents a perspective view from another angle of the side beam of Figure 2 in assembled configuration; And

- [Fig 4] is a perspective view of the exterior reinforcement of one of the two side rails of the body base of Figure 1.

[Detailed description]

[20] Figure 1 is a partial view of a body structure 1 of a hybrid or electric type motor vehicle.

[21] We define in relation to this vehicle a direct orthogonal reference frame XYZ comprising three perpendicular axes in pairs, namely:

- a horizontal longitudinal axis X, parallel to the ground and oriented in the general direction of movement of the vehicle;

- a horizontal transverse axis Y, also parallel to the ground and perpendicular to the axis X; And

- a vertical Z axis, perpendicular to the ground as well as to the horizontal XY plane.

[22] In the description which follows and by convention, the terms “lower”, “upper”, “front” and “rear” will be understood in relation to the general orientation of the vehicle. The terms “lower” and “lower” will indicate greater proximity to the ground in the vertical direction than the terms “upper” or “high”. The term “front” will indicate a positioning towards the front of a vehicle in the horizontal direction and the term “rear” will indicate a positioning towards the rear of a vehicle in the same horizontal direction.

[23] The terms “external” and “internal” will be used to define the relative position of an element with reference to the median longitudinal axis of the vehicle. The element closest to this axis will thus be qualified as internal as opposed to the other element further from this same axis which will be qualified as external.

[24] Furthermore, the term “substantially” will be used to indicate that a slight deviation is permitted from a predetermined nominal position or arrangement, while remaining included within the scope of the invention. For example, “substantially vertical” will indicate that a deviation of around 20° from a strictly perpendicular orientation is admitted within the framework of the invention.

[25] With reference to Figure 1, the body structure 1 comprises a body base 2 according to the invention comprising a front floor 3 extending longitudinally between the front apron 4 and the rear floor 5 intended to support the rear seats (also called “row two seats”), and transversely between two base side rails 10 (only the left side rail 10 is visible in this figure 1).

[26] A middle pillar 6 separating the front and rear side doors connects each side rail 10 to a corresponding roof side frame 7 of the vehicle (only the left middle pillar 6 and a portion of the left roof side frame 7 being represented on the figure 1 ).

[27] A propulsion battery not visible in this figure 1 is also installed under the front floor 3 of the vehicle between the two side beams of the base 10.

[28] The body base 2 also comprises two metal seat crossmembers 8, 9 spaced longitudinally from each other and fixed on top of the front floor 3 extending transversely between the two side base members 10 to which they are also attached.

[29] The first seat crosspiece 8 is located directly above the two middle legs 6 while the second 9 is located in front of the latter.

[30] Presenting an inverted U-shaped section (that is to say open towards the bottom), these front seat crossmembers 8, 9 constitute anchoring supports for the seat frames of the front seats by via two pairs of slides not shown, each comprising, in a conventional manner, a lower rail whose two ends are respectively fixed on one and the other of these crosspieces 8, 9 as well as an upper rail mounted sliding on the lower rail and rigidly connected to a corresponding lower side part of the seat frame of a corresponding seat.

[31] With reference to Figure 2, each lateral base beam 10 comprises an elongated hollow body 11 of closed cross section delimiting an interior cavity of substantially square section, this hollow body being consisting of an internal spar part 12 and an external spar part 13.

[32] These internal 12 and external 13 parts forming the hollow body 11 are each obtained by stamping from one or more sheets of metal sheet, preferably made of double-phase steel and advantageously having a thickness of between 1.2 and 1 .4 millimeters.

[33] The internal part 12 of each spar 10 has a profile in section substantially in the shape of a lying U and the opening of which faces away from the front floor 3 of the vehicle to which it is fixed. This internal part 12 comprises a substantially vertical lateral core 12A as well as two upper flanges 12B and lower 12C extending substantially horizontally opposite the front floor 3 from this lateral core 12A. The upper 12B and lower 12C flanges each extend opposite the lateral web 12A respectively by an upper junction rabbet 12D and by a lower junction rabbet 12E folded towards the outside of the U.

[34] Similar in construction to the internal part, the external part 13 of each spar 10 has a profile in section substantially in the shape of a lying U and the opening of which faces towards the front floor 3 of the vehicle. This external part 13 comprises a substantially vertical lateral core 13A as well as two upper flanges 13B and lower 13C extending substantially horizontally in the direction of the front floor 3 from this lateral core 13A. The upper 13B and lower 13C flanges each extend opposite the lateral web 13A respectively by an upper junction rabbet 13D and by a lower junction rabbet 13E folded towards the outside of the U.

[35] The internal 12 and external 13 parts of each spar 10 are fixed to each other by welding their upper junction rabbets 12D, 13D and by that of their lower junction rabbets 12E, 13E.

[36] Each spar 10 also includes an interior reinforcement 14 extending longitudinally along and inside said hollow body 11 to which it is rigidly fixed. [37] This internal spar reinforcement 14 is constituted in this case by a metal profile preferably obtained by extrusion and advantageously made of aluminum or an aluminum alloy.

[38] Equipped with a cross section of substantially rectangular or square shape and occupying most of the interior volume of the hollow body 11, the interior spar reinforcement 14 has a cellular structure composed of an exterior envelope 14A of rectangular section and a network of interior partitions 14B crisscrossing the interior volume of this envelope 14A.

[39] Each spar 10 further comprises an external reinforcement 15 attached fixedly against the exterior face of a central zone of the internal part 12 of the hollow body 11 of the spar 10, located opposite the corresponding lateral ends of the two front seat crossmembers 8, 9.

[40] The exterior reinforcement 15 of each spar 10 is obtained by cold stamping from a sheet of metal sheet preferably made of double-phase steel (for example, in DP 780) and advantageously having a thickness of between 1.5 and 2.5 millimeters.

[41] Presenting in section a transverse profile in the shape of an inverted L, each external reinforcement 15 comprises a substantially vertical side wing 15A placed against the external face of the lateral core 12A of the internal part 12 of the hollow body 11 of the corresponding spar 10 , as well as an upper wing 15B extending substantially horizontally opposite the front floor 3 from this lateral core 15A and being placed against the exterior face of the upper sole 12B of this internal part 12.

[42] Advantageously and as illustrated in Figure 3, the side wing 15A of each said external reinforcement 15 extends vertically on either side of the front floor 3 over at least most of the height of the lateral core 12A of the internal part 12 of the corresponding spar 10.

[43] Its upper wing 15B extends transversely over at least most of the width of the upper flange 12B of the internal part 12 of the corresponding spar 10.

[44] As illustrated in Figure 1, each lateral end of the seat crosspieces 8, 9 is fixed to the corresponding side beam 10 via tabs 8A, 9A projecting transversely from said end and welded to the upper wing 15B of the external reinforcement 15 of this lateral spar 10.

[45] As illustrated in Figures 3 and 4, the exterior reinforcement 15 of each lateral spar 10 advantageously has a certain number of cutouts 16 made at certain respective zones of the internal part 12 of this spar 10 provided with holes 17 intended for fixing by clipping clips of electrical harness fasteners not shown.

[46] According to alternative embodiments not shown, the body base can be shaped differently and include, for example, only one seat crossmember.

[47] Numerous other variants are also possible and it will be recalled in this regard that the invention is not limited to the embodiments described and represented, but also encompasses all the execution variants within the reach of those skilled in the art. .

Claims

Claims

[Claim 1] Body base (2) for a hybrid or electric type motor vehicle, comprising a floor (3) extending transversely between two side base members (10) as well as at least one seat crossmember (8 , 9) fixed on the top of said floor (3) and extending transversely between the two said side rails (10) to which it is fixed; each said lateral spar (10) comprising an elongated hollow body (11) of closed cross section and consisting of an internal spar part (12) as well as an external spar part (12) fixed to one another other, each said lateral spar (10) also comprising an interior reinforcement (14) extending longitudinally along and inside its hollow body (11); characterized in that each said lateral spar (10) further comprises an external reinforcement (15) attached fixedly against the exterior face of a zone of said internal part of the spar (12) located opposite said at least a seat crosspiece (8, 9).

[Claim 2] Body base (2) according to claim 1, characterized in that the internal part (12) of each said lateral beam (10) has in section a profile in the shape of a lying U and comprises a lateral core (12A ) as well as two upper (12B) and lower (12C) flanges extending opposite said floor (3) from this lateral core (12A), said external reinforcement (15) of each said lateral spar (10) having in section an inverted L-shaped profile and comprising a side wing (15A) placed against the exterior face of said side web (12A) as well as an upper wing (15B) extending opposite said floor (3) from this lateral core (15A) being placed against the exterior face of said upper sole (12B).

[Claim 3] Body base (2) according to claim 2, characterized in that each lateral end of said at least one seat crossmember (8, 9) is fixed to the corresponding lateral longitudinal member (10) by means of tabs (8A, 9A) projecting transversely from said end and welded to the upper wing (15B) of the external reinforcement (15) of this spar

[Claim 4] Body base (2) according to one of claims 2 or 3, characterized in that the lateral wing (15A) of each said external reinforcement (15) extends vertically on either side of said floor (3) over at least most of the height of the lateral web (12A) of the internal part (12) of the corresponding beam (10).

[Claim 5] Body base (2) according to one of claims 1 to 4, characterized in that the external reinforcement (15) of each said side member (10) has cutouts (16) made in certain areas respective parts of the internal part (12) of this spar (10) provided with fixing holes (17).

[Claim 6] Body base according to (2) one of claims 1 to 5, characterized in that the external reinforcement (15) of each said side member (10) is obtained from a sheet of metal sheet in double-phase steel having a thickness of between 1.5 and 2.5 millimeters.

[Claim 7] Body base (2) according to one of claims 1 to 6, characterized in that the interior reinforcement (14) of each said side member (10) is constituted by a metal profile obtained by extrusion.

[Claim 8] Body base (2) according to one of claims 1 to 7, characterized in that the interior reinforcement (14) of each said side member (10) has a cellular structure composed of an exterior envelope (14A ) and a network of interior partitions (14B) crisscrossing the interior volume of this envelope (14A).

[Claim 9] Body base (2) according to one of claims 1 to 8, characterized in that it comprises two said seat crosspieces (8, 9) spaced longitudinally from one another.

[Claim 10] Motor vehicle comprising a body base (2) according to one of claims 1 to 9.