Chassis for motor vehicle traction battery pack with extruded structural section

Abstract

The invention relates to a chassis for a motor vehicle battery pack comprising a rectangular frame (110) formed of two side members (111) and two cross members (112) fixed at their ends, said side members and said cross members being constituted by metal profiles of the same section each comprising: - an upper sealing portion (PSE) extending vertically and having an upper face intended to receive in a sealed manner the peripheral periphery of an upper cover; and - a connection portion (PC) extending below said upper sealing portion, projecting laterally on either side of the latter along external and internal lateral overhangs on which are intended to be fixed supports for attachment to the underbody and battery modules (200, 200');each said profile also comprises a lower ground clearance portion (PGS) extending vertically below said connection portion. Figure to be published with the abstract: Fig. 6;

Description

Title of the invention: Chassis for a motor vehicle traction battery pack with extruded structural section Technical field

[0001] The present invention relates to electrically powered motor vehicles equipped with a propulsion battery pack. It relates in particular to a chassis for such a motor vehicle battery pack. Prior art

[0002] Electrically powered motor vehicles are becoming increasingly popular due to their reduced environmental impact, often lower operating costs, and continued advances in battery technology, improving the range and performance of electric vehicles.

[0003] Public awareness campaigns on the environmental and economic benefits of this technology, as well as traffic restrictions implemented in many urban areas, are also encouraging owners of motor vehicles with internal combustion engines to convert them to electric vehicles by integrating an electric powertrain and a battery to replace the thermal engine and fuel tank.

[0004] Such a conversion, commonly referred to as an “automotive retrofit”, allows owners of older vehicles to continue to use them in regulated low-emission zones (LEZs) while benefiting from the advantages of electric propulsion, such as reduced emissions, lower fuel costs, and often simpler maintenance.

[0005] The propulsion battery of an electrically powered motor vehicle conventionally comprises several battery modules, each comprising a plurality of electrochemical cells capable of generating current by chemical reaction (these cells may, for example, be of the Li-ion type, of the Ni-Mh type, or even Ni-Cd).

[0006] These battery modules are mounted on a metal chassis to form a battery pack, more commonly referred to by the English expression "battery pack", and also comprising an upper cover and a lower floor fixedly attached to this chassis and covering these battery modules from above and below respectively, electrical connection sockets and fluid circulation cooling devices, as well as electrical or electronic means for managing the electrical energy of these modules.

[0007] Such a battery pack is commonly installed fixedly under the underbody of vehicle body so as not to impact the habitability of this vehicle while ensuring sufficient autonomy. Such an installation is also often mandatory for vehicles converted to electric propulsion known as “retrofitted” for which structural modifications must be limited both for cost and homologation reasons.

[0008] To be approved in Europe, these battery packs must therefore comply with the ECE R100 regulation requiring that they satisfy a series of mechanical, electrical and environmental tests.

[0009] Having to be able to withstand very significant mechanical forces simulating frontal, rear or lateral collisions (in particular compliance with longitudinal and transverse deflection criteria) in order to avoid any risk of short circuit or electrolyte leakage, the frames of these battery packs are commonly made up of several stamped sheet metal parts of different geometry, each obtained from dedicated dies, and assembled together.

[0010] Developed specifically for the vehicle model on which they are to be installed, these chassis are thus relatively expensive in terms of design and manufacture, which proves to be particularly problematic for players in the electric “retrofit” sector whose objective is to offer electric conversion kits at attractive prices.

[0011] Also known from document EP 3 379 598 B1 is a metal chassis for such a battery pack comprising a rectangular frame formed of two longitudinal side members and two transverse cross members fixed to each other by welding at their ends.

[0012] The side members and cross members forming this frame are made up of metal profiles of the same section, formed in an aluminum alloy by a thermomechanical extrusion process, and each comprising: - an upper sealing portion extending vertically and having an upper face intended to receive in a sealed manner the peripheral periphery of the upper cover of the battery pack; and - a connection portion extending below the upper sealing portion, projecting laterally on either side of the latter, respectively from an external lateral overhang and an internal lateral overhang on which the attachment supports of this battery pack to the underbody of the vehicle and a first end of the battery modules are respectively intended to be fixed by bolting.

[0013] Forming the outer periphery of the chassis, the connecting portion of the profiles constituting the frame undergoes a very high compressive stress during the collision process. This connecting portion is therefore configured to absorb by deforming a large part of the energy generated during such a collision, so as to effectively protect the fixed battery modules by preventing their crushing which could cause the deterioration of some of their cells and create a risk of electrocution or chemical burns for the passengers.

[0014] This metal chassis also comprises a longitudinal reinforcing element, extending longitudinally between the two crosspieces of the frame to which its ends are welded, and on which the second end of the battery modules is intended to be fixed by bolting.

[0015] The chassis further comprises a plurality of transverse reinforcing elements extending transversely, intersecting with the longitudinal reinforcing element between the two side members of the frame to which their ends are welded, so as to delimit receiving housings for these battery modules.

[0016] The cost of developing and manufacturing such a chassis is significantly lower than that of a conventional chassis, which makes it particularly suitable for electrical retrofitting. Due to its design, its dimensions and its compartmentalization can also be easily adjusted so as to allow the installation of said chassis on a wide variety of motor vehicle underbodies and / or to accommodate a wide range of battery modules from different suppliers.

[0017] This type of chassis does not, however, provide effective protection for certain sensitive elements of the battery pack (such as the battery modules in particular) in the event, for example, of the vehicle being lifted with a rolling jack resting on the chassis frame or when the vehicle is crossing or descending pavements. Statement of the invention

[0018] The present invention therefore aims to improve the situation.

[0019] To this end, it proposes a chassis for a motor vehicle battery pack comprising a rectangular frame formed of two longitudinal side members and two transverse cross members fixed to each other at their ends, said side members and said cross members being constituted by metal profiles of the same section each comprising: - an upper sealing portion extending vertically and having an upper face intended to receive in a sealed manner the peripheral periphery of an upper cover of said battery pack; and - a connection portion extending below said upper sealing portion, projecting laterally on either side of the latter, respectively from an external lateral overhang and an internal lateral overhang on which are respectively intended to be fixed attachment supports to the underbody of said vehicle and battery modules.

[0020] According to the invention, each said profile also comprises a lower ground clearance portion extending vertically below said connection portion.

[0021] The presence of such a lower portion of ground clearance makes it possible to protect the battery pack (in particular the battery modules and certain other sensitive elements such as fluid circulation pipes of the cooling devices and the electrical supply harnesses) in the event, for example, of the vehicle being lifted with a rolling jack resting on the chassis frame or even when the vehicle is crossing or descending curbs.

[0022] In order to balance the section in the thermomechanical extrusion process for manufacturing the profiles, said lower ground clearance portion preferably extends directly above said upper sealing portion and over a width equal to that of this upper sealing portion.

[0023] In order to ensure perfect sealing at the junctions between the lower ground clearance portions of the side members and the cross members, said lower ground clearance portion of each end of a said side member is advantageously assembled along a vertical welding plane with the lower ground clearance portion of the corresponding end of a said cross member.

[0024] In order to ensure optimal protection of the sensitive elements of the battery pack, said lower ground clearance portion preferably extends over a height greater than or equal to 10 millimeters.

[0025] In order to balance the section in the thermomechanical extrusion process for manufacturing the profiles, said lower ground clearance portion advantageously extends directly above said upper sealing portion and over a width equal to that of this upper sealing portion.

[0026] For reasons of ease of construction, said lower ground clearance portion comprises an outer casing of rectangular section forming its outer profile and defining an inner cavity.

[0027] In order to improve its mechanical resistance, said lower ground clearance portion may comprise at least one flat reinforcing rib extending between two opposite sides of its outer casing so as to divide its inner cavity into a plurality of sub-cavities.

[0028] To ensure better balance of the section during the process of producing the profiles so as to limit deformations during their cooling, but also to limit the number of tools necessary for holding these profiles during the machining phases of their ends, said external and internal lateral overhangs of said connection portion are preferably symmetrically identical with respect to the median vertical plane of said upper sealing portion.

[0029] In order in particular to redirect, in the event of a collision in a longitudinal or transverse direction, part of the longitudinal or transverse bending forces undergone by the profiles forming the frame towards the lower part of this frame, said connection portion advantageously comprises an outer envelope forming its outer profile and defining an inner cavity, said outer envelope having in section a bevelled rectangle shape whose two lower lateral vertices are constituted by two inclined sides forming an angle of inclination with the horizontal.

[0030] For an optimum result, this inclination angle 0 is for example between 15 and 30°.

[0031] In order to achieve the watertight closure of the upper sealing portions of the crosspieces, the upper sealing portion of each end of a said side member is preferably assembled along a vertical longitudinal welding plane with the upper sealing portion of the corresponding end of a said crosspiece.

[0032] In order to favor the transmission of forces from the side members to the cross members or vice versa in the event of an impact in a transverse or longitudinal direction, at least a part of the connection portion of each end of a said side member is advantageously assembled along a vertical welding plane with a respective part of the connection portion of the corresponding end of a said cross member.

[0033] In order to improve the mechanical resistance of the chassis in the event of an impact but also to facilitate the fixing of the battery modules to this chassis, the latter may also comprise at least one metal reinforcing element extending longitudinally or transversely inside the frame between the two said side members or between the two said ribs of this frame to which its two ends are fixed by welding.

[0034] In order to reduce the cost of development and manufacturing of the chassis, each said reinforcement element is advantageously made from a metal profile with a section identical to that of said side members and said cross members.

[0035] The invention also relates, in a second aspect, to a battery pack intended to be fixedly installed against the underbody of a motor vehicle and comprising such a chassis and several battery modules mounted on this chassis.

[0036] Finally, the invention aims, in a third aspect, at a motor vehicle comprising such a battery pack. Brief description of the drawings

[0037] The description of the invention will now be continued by the detailed description of several exemplary embodiments, given below for illustrative but non-limiting purposes, with reference to the appended drawings, in which: - [Fig.l] represents an exploded perspective view of a vehicle battery pack automobile comprising a chassis according to the invention; - [Fig.2] is a perspective view in assembled configuration of the battery pack of [Fig.l], in which certain elements including the top cover have been omitted in order to facilitate reading; - [Fig.3] represents a perspective view of the chassis according to the invention of the battery pack of figures 1 and 2; - [Fig.4] is an exploded perspective view of the chassis of [Fig.3]; - [Fig.5] represents a view of the section of the profiled elements constituting the frame of [Fig.3]; - [Fig.6] is a sectional view of the front end portion of the battery pack of Figures 1 and 2, taken along a vertical longitudinal plane; - [Fig.7], [Fig.8] and [Fig.9] represent views of the sectional profile of the profiled elements constituting a chassis according to several variant embodiments of the invention; and - [Fig. 10] is a perspective view in assembled configuration of a battery pack provided with the chassis according to the invention but comprising battery modules different from the battery pack of figures 1 and 2, view in which certain elements including the upper cover have been omitted in order to facilitate reading. Description of the embodiments

[0038] Figures 1 and 2 represent a battery pack 1 intended to be installed under the underbody of a motor vehicle (not shown), in particular in the context of the installation of an electrification kit for this vehicle.

[0039] We define with respect to this battery pack 1 an orthogonal reference frame XYZ comprising three axes perpendicular two by two, namely: - an X axis, defining a longitudinal, horizontal direction, parallel to the ground and coincident with the general direction of movement of the vehicle - a Y axis, defining a transverse, horizontal direction, also parallel to the ground and which with the X axis defines a horizontal XY plane, and - a Z axis, defining a vertical direction, perpendicular to the ground as well as to the horizontal XY plane.

[0040] In the remainder of the description and with reference to the reference defined above, the terms “longitudinal” or “longitudinally” will refer to a direction parallel to the X axis, the terms “transverse” or “transversely” will refer to a direction parallel to the Y axis, and the terms “vertical” or “vertically” will refer to a direction parallel to the Z axis.

[0041] On the other hand and by convention, the terms “lower”, “upper”, “front” and “rear” will be understood in relation to the general orientation of the battery pack 1 in its configuration mounted on a vehicle. The terms "lower" and "lower" will indicate a closer proximity to the ground in the vertical direction than the terms "upper" or "high." The term "front" will indicate a positioning oriented towards the front of a vehicle in the horizontal direction and the term "rear" will indicate a positioning oriented towards the rear of a vehicle in the same horizontal direction.

[0042] With reference to figures 1 and 2, the battery pack 1 comprises: - a chassis 100 according to the invention defining an internal volume Vi and which will be described in more detail later; - several battery modules 200 fixedly mounted on this chassis 100; - several cooling devices 300 each fixedly attached to the lower face of a corresponding battery module 200; - a 400 power electronics box; - a 500 support bridge carrying this 400 power electronic box; - several electronic control systems 600 of the battery modules 200; - several rigid electrical connection braids 700 ensuring the high voltage electrical connection between the battery modules 200 and the power electronics box 400; - an upper cover 800 covering the battery modules 200, the power electronics box 400 as well as the electronic control systems 600; - several external 900 sealing flanges; - at least one 1000 electrical connection socket; - several attachment brackets 1100 allowing the battery pack 1 to be rigidly fixed against the underbody of the vehicle; and - two lower half-floors 1200 extending below the battery modules 200.

[0043] Housed in the internal volume Vi of the chassis 100, the battery modules 200 each comprise a plurality of electrochemical cells capable of generating current by chemical reaction.

[0044] Each cooling device 300 comprises a cold plate 310 covering a coil (not visible) in which a cooling liquid circulates intended to absorb and dissipate the heat generated during the operation of the battery pack 1.

[0045] The power electronics box 400 integrates electronic components, such as inverters, to convert the electrical energy stored in the battery modules 200 into a form usable by the electric powertrain of the vehicle.

[0046] As illustrated in [Fig. 1], the support bridge 500 comprises two lateral legs 510 fixed by bolting to the internal lateral parts of the chassis 100 as well as an apron 520 overhanging the battery modules 200 and on which the housing of power 400 so as to keep it away from these 200 battery modules.

[0047] Commonly referred to by the English acronym BMS for “Battery Management System”, the electronic control systems 600 ensure the balancing of the charges of all the cells of the same battery pack 200 in order to prevent undervoltages or overvoltages.

[0048] The upper cover 800 has several orifices 810 through which the inlet 320 and outlet 330 pipes of the coils of the cooling devices 300 pass. Fixedly attached against the outer face of this cover 800 at the level of the orifices 810, the outer sealing flanges 900 make it possible to ensure the sealed connection between these inlet 320 and outlet 330 pipes and flexible pipes, not shown, for connection to the fluid cooling circuit of the vehicle.

[0049] Intended to ensure the electrical connection between the battery pack and the electric powertrain of the vehicle, the electrical connection socket(s) 1000 are fixedly attached against an external longitudinal end wall of the chassis 110 as will be seen in more detail later.

[0050] Extending from the outer peripheral periphery of the chassis 100, the attachment supports 1100 are intended to ensure the fixing of the battery pack 1 against the underbody of the vehicle 100.

[0051] Finally, the two half-floors 1200 made from cut sheet metal are fixedly attached in a sealed manner against the chassis 100, each below a corresponding battery module 200 so as to protect it.

[0052] The chassis according to the invention 100 will now be described in detail with reference to FIGS. 3 to 5.

[0053] The chassis 100 comprises a rectangular metal frame 110 formed of two longitudinal side members 111 and two transverse cross members 112 fixed to each other by welding at their ends.

[0054] As can be seen in particular in Figures 3 and 4, the side members 111 and the cross members 112 forming this frame 110 are made up of metal profiles having an identical P profile in section (see [Fig.5]) and obtained by a mechanical extrusion process from the same die.

[0055] With reference to this [Fig. 5], each profile 111, 112 comprises an upper sealing portion PSE oriented vertically and having an upper face FPSE provided to receive in a sealed manner the peripheral periphery of the upper cover cover 800 of the battery pack 1 (the sealing being obtained by means of a seal or a joint bead not shown and interposed between this upper face Fpse and this cover 800).

[0056] The upper sealing portion PSE comprises an outer casing of rectangular section Epse forming its outer profile and defining an in- exterior.

[0057] This upper sealing portion PSE also advantageously comprises at least one flat reinforcing rib extending between two opposite sides of this outer envelope Epse so as to divide this inner cavity into a plurality of sub-cavities.

[0058] The presence of such reinforcing ribs makes it possible to improve the mechanical resistance of this upper PSE sealing portion in the event of a collision in a longitudinal or transverse direction, so as to limit its bending curvature (these reinforcing ribs absorbing part of the impact energy).

[0059] Such a structure thus makes it possible to limit the mass of the upper PSE sealing portion while allowing it to have excellent mechanical resistance.

[0060] In this case, the upper sealing portion PSE comprises a single horizontal flat reinforcing rib NHPSE extending at its median horizontal plane between the two vertical lateral sides of the outer envelope Epse, so as to divide its internal cavity into two superimposed sub-cavities of identical dimensions.

[0061] According to embodiment variants not shown, the number and / or arrangement of the flat reinforcing ribs may vary.

[0062] The upper PSE sealing portion could thus comprise, for example, at least one flat reinforcing rib extending vertically between the two upper and lower sides of the outer EPS envelope.

[0063] This upper PSE sealing portion could also comprise at least one flat reinforcing rib extending obliquely (i.e. neither vertically nor horizontally) between the two vertical side panels or between the upper and lower panels of the outer EPS envelope.

[0064] It will be noted that the width 1PSE of the upper sealing portion PSE (and therefore of this upper face FPSE) will preferably be greater than or equal to 20 millimeters in order to obtain a sufficient joining surface to guarantee perfect sealing.

[0065] It will also be noted that the height hPSE of this upper PSE sealing portion will preferably be greater than or equal to 65 millimeters so as to allow the installation of one or more electrical connection sockets 1000 against its external face as illustrated by [Fig.6].

[0066] Again with reference to [Fig. 5], each profile 111, 112 also comprises a connection portion PC oriented horizontally and extending below the upper sealing portion PSE, projecting laterally on either side of the latter, respectively with an external lateral overhang DEPC and an internal lateral overhang DIPC, preferably symmetrically identical with respect to the median vertical plane of the upper sealing portion PSE.

[0067] This connection portion PC is intended, on the one hand, to absorb the majority of the energy generated in the event of a collision in a longitudinal or transverse direction, and on the other hand to allow the battery modules 200 and the attachment supports 1100 to be fixed to the frame 110 as well as the cross members 112 of this frame 110 directly to structural elements of the underbody of the vehicle.

[0068] The connection portion PC comprises an outer casing EPC forming its outer profile and defining an inner cavity. This outer casing EPC has in section a beveled rectangle shape whose two lower lateral vertices are constituted by two inclined planes PPC forming with the horizontal an angle of inclination 0 advantageously between 15 and 30°. The presence of such inclined planes PPC makes it possible in particular to redirect, in the event of a collision in a longitudinal or transverse direction, a part of the longitudinal or transverse bending forces undergone by the profiles 111, 112 forming the frame 110 towards the lower part of this frame 110.

[0069] Just like the upper sealing portion PSE, this connection portion PC also advantageously comprises at least one flat reinforcing rib extending between two opposite sides of this outer envelope PPC so as to divide its interior cavity into a plurality of sub-cavities.

[0070] The presence of such reinforcing ribs makes it possible to improve the mechanical resistance of this PC connection portion in the event of a collision in a longitudinal or transverse direction, so as to limit its bending curvature (these reinforcing ribs then absorbing part of the impact energy).

[0071] Such a structure thus makes it possible to limit the mass of the PC connection portion while allowing it to have excellent mechanical resistance.

[0072] In this case and as illustrated by [Fig. 5], the connection portion PC comprises a horizontal reinforcing flat rib NHPC extending at its median horizontal plane between the two vertical lateral panels of the outer envelope EPC, as well as two other vertical reinforcing flat ribs, respectively internal NVIPC and external NVEPC, extending vertically between the upper and lower panels (advantageously at the intersections between the lower panel and the two inclined panels PPC) and laterally on either side of the upper sealing portion PSE, so as to divide its internal cavity into six sub-cavities.

[0073] As can be seen in particular in Figures 3 and 4, the external overhangs DEPC of the side members 111 are provided with holes crossed by hollow attachment studs 120 welded around the perimeter of these holes and intended to ensure the fixing by bolting of the attachment supports 1100 on the frame 110.

[0074] Still with reference to these figures 3 and 4, the external overhangs DEPC of the crosspieces 112 are also provided with holes crossed by hollow attachment studs 120 welded around the perimeter of these holes and intended to ensure the fixing by bolting of these crosspieces 112 on structural elements of the underbody of the vehicle.

[0075] In order to ensure the fixing of these attachment supports 1100 and of these structural elements of the body underbody on these cross members 112 while guaranteeing the assembly clearances with the latter, the external overhang DEPC of the profiles 111, 112 preferably extends over a width lDE of at least 50 millimeters (see [Fig.5]).

[0076] Furthermore, this external overhang DEPC being the first to be impacted in the event of a collision, it is understood that the greater its width, the more it will be able to absorb a significant portion of the energy of this impact. In order to obtain an optimal compromise between the volume occupied by the frame 110 and the absorption of energy, this width 1DE will thus advantageously be between 55 and 65 millimeters.

[0077] As can be seen in particular in Figures 3, 4 and 6, the internal overhangs DIPC of the crosspieces 112 are provided with holes on which nuts 130 are crimped, making it possible to ensure the fixing by bolting on the chassis 100 of a first longitudinal end of the battery modules 200 using screws V.

[0078] In order to ensure the fixing of these battery modules 200 on the frame 110 while guaranteeing the mounting clearances with the latter, the internal overhang DIPC of the profiles 111, 112 preferably extends over a width lD1 of at least 30 millimeters (see [Fig.5]).

[0079] It will also be noted that the height hPC of the connection portion PC will preferably be greater than or equal to 30 millimeters so as to ensure effective protection of the cooling devices 300 extending under the battery modules 200.

[0080] According to the invention, each profile 111, 112 finally comprises a lower ground clearance portion PGS extending vertically below the connection portion PC.

[0081] This lower portion of ground clearance PGS comprises an outer casing of rectangular section EPGS forming its outer profile and defining an inner cavity. In this case, it is devoid of a reinforcing rib.

[0082] The presence of such a lower portion of ground clearance PGS makes it possible to protect the battery pack 1 (in particular the battery modules 200 and certain other sensitive elements such as the coils of the cooling devices 300 and the electrical power supply harnesses) in the event, for example, of the vehicle being lifted with a rolling jack resting on the frame 110 of the chassis 100 or even when the vehicle is crossing or descending pavements.

[0083] In order to ensure optimal protection, the height hPGs of this lower portion of ground clearance PGS will preferably be greater than or equal to 10 millimeters and advantageously between 10 and 20 millimeters.

[0084] Furthermore, and in order to balance the section in the thermomechanical extrusion process for manufacturing the profiles 111, 112, this lower ground clearance portion PGS preferably extends directly above the upper sealing portion PSE and over a width lPGS equal to that 1PSE of this upper sealing portion PSE.

[0085] As illustrated by figures 3 and 4, the ends 111A, 112A of the side members 111 and the cross members 112 are machined to fit together by complementary shape so as to allow them to be welded.

[0086] More precisely, the internal lateral face of the upper sealing portion PSE of each machined end 11 IA of a spar 111 is assembled along a vertical longitudinal welding plane with the edge of the upper sealing portion PSE of the corresponding machined end 112A of a crossmember 112, so as to achieve the sealed closure of the internal cavity of these upper sealing portions PSE of the crossmembers 112 on which the electrical connection socket(s) 1000 of the battery pack 1 are connected (such fluidic isolation of the upper sealing portions PSE of the crossmembers 112 with respect to those of the spars 111 making it possible to avoid any risk of short circuit).

[0087] The edge of the internal section TIPC of the connection portion PC of each machined end 11 IA of a spar 111 (i.e. the section extending over the internal side from the internal vertical reinforcing rib NVIPC) is assembled along a vertical welding plane at an angle of 45° with respect to the longitudinal and transverse directions with the edge of the internal section TIPC of the connection portion PC of the corresponding machined end 112A of a cross member 112.

[0088] Such an assembly of the respective internal TIPC sections of the machined ends 111A, 112A of the side members 111 and the cross members 112 makes it possible to ensure both a partial transmission of the longitudinal forces undergone by the cross members 112 towards the side members 111 in the event of a longitudinal impact, and also a partial transmission of the transverse forces undergone by the side members 111 towards the cross members 112 in the event of an impact in a transverse direction.

[0089] The coplanar sections of the central TCPC and external TEPC sections of the connection portion PC of each machined end 11 IA of a spar 111 (i.e. the sections extending respectively between the two internal vertical reinforcing ribs NVIPC and external NVEPC, and projecting on the external side from the external vertical reinforcing rib NVEPC) are for their part assembled according to a vertical transverse welding plane with the internal vertical reinforcing rib NVIPC forming the internal limit of the central TCPC and external TEPC sections of the connection portion PC of the corresponding machined end 112A of a crossmember 112.

[0090] Such an assembly of the respective central TCPC and external TEPC sections of the connection portion PC of the machined ends 111 A, 112A of the side members 111 and the cross members 112 allows, as illustrated by this [Fig.4], to install hollow attachment studs 120 on the external overhangs DEPC of the cross members 112 as close as possible to the corner zones of the frame 110 but also to favor the transmission of the longitudinal forces undergone by the cross members 112 towards the side members 111 in the event of an impact in a longitudinal direction.

[0091] According to alternative embodiments not shown, the coplanar sections of the central TCPC and external TEPC sections of the connection portion PC of each machined end 11 IA of a cross member 112 can be assembled along a vertical longitudinal welding plane with the internal vertical reinforcing rib NVIPC forming the internal limit of the central TCPC and external TEPC sections of the connection portion PC of the corresponding machined end 11 IA of a spar 111.

[0092] Such an assembly of the respective central TCPC and external TEPC sections of the connection portion PC of the machined ends 111 A, 112A of the side members 111 and the cross members 112 makes it possible to install hollow attachment studs 120 on the external overhangs DEPC of the side members 111 as close as possible to the corner zones of the frame 110 but also to favor the transmission of the transverse forces undergone by the side members 111 towards the cross members 112 in the event of an impact in a transverse direction.

[0093] Generally speaking and in order to favor the transmission of forces from the side members to the cross members 112 or vice versa in the event of an impact in a transverse or longitudinal direction, at least a part of the connection portion PC of each end 11 IA of a side member 111 will advantageously be assembled along a vertical welding plane with a respective part of the connection portion PC of the corresponding end 112A of a cross member 112.

[0094] Finally, the edge of the lower ground clearance portion PGS of each machined end 11 IA of a side member 111 is assembled along a vertical transverse welding plane with the internal lateral face of the lower ground clearance portion PGS of the corresponding machined end 112A of a cross member 112, so as to achieve the watertight closure of the internal cavity of these lower ground clearance portions PGS of the side members 111.

[0095] Referring again to [Fig. 3], the chassis 100 also preferably comprises at least one metal reinforcing element 140 extending longitudinally or transversely inside the frame 110 between the two side members 111 or between the two ribs 112 of this frame to which its two ends are fixed by welding.

[0096] This or these metal reinforcements 140 are advantageously constituted by metal profiles having in section the same profile P as that of the side members 111 and the cross members 112 of the frame 110, so as to reduce the cost of development and fa construction of the chassis 100 (use of a single extrusion die for the manufacture of all the profiles 111, 112 and 140 of this chassis 100).

[0097] In this case and as can be seen in Figures 3 and 4, the chassis 100 comprises a single reinforcement 140 extending transversely between the two central zones of the side members 111 of the frame 110.

[0098] The internal DIPC and external DEPC overhangs of this transverse reinforcement 140 are provided with holes on which nuts 130 are crimped to ensure the fixing by bolting on the chassis 100 of the second longitudinal end of the battery modules 200.

[0099] It will also be noted that these internal DIPC and external DEPC overhangs of the transverse reinforcement 140 are provided with oblong passage notches 141 crossed by the inlet 320 and outlet 330 pipes of the coils of the cooling devices 300.

[0100] It will be noted on this occasion that the fact that these internal DIPC and external DEPC overhangs are symmetrically identical makes it possible to balance the section during the process of producing by extrusion the profiles 111, 112 and 140 so as to limit the deformations during their cooling, but also to limit the number of tools necessary for holding these profiles during the machining phases of their ends.

[0101] It will also be noted that the four sides of the peripheral edge of the upper face of each rectangular half-floor 1200 are respectively fixedly and tightly attached by welding against the lower face of the internal overhang of a corresponding crosspiece 112, against the lower faces of the internal overhangs DI PC of the corresponding halves of the side members 111 and against the lower face of the internal overhang DIPC or external overhang DEPC of the transverse reinforcement 140, so as to fluidly isolate the battery modules 200 from water splashes.

[0102] As illustrated by [Fig.4], the ends 140A of the transverse reinforcement 140 are machined to fit together by complementary shape on the central zones of the two side members 111 of the frame 110, so as to allow them to be welded.

[0103] Alternatively, the number and / or arrangement of the flat reinforcing ribs inside the profiles 111, 112 and 140 may vary.

[0104] [Fig.7] illustrates a section profile P' of a profile similar to that of [Fig.5] at with the exception of its connection portion PC' which is devoid of horizontal reinforcing flat rib such as NHPC and comprises only the two vertical reinforcing flat ribs respectively internal NVIPC and external NVEPC extending vertically between the upper and lower sides (advantageously at the level of the intersections between the lower side and the two inclined sides PPC) and laterally on either side of the upper sealing portion PSE, so as to divide its interior cavity into three sub-cavities.

[0105] [Fig.8] illustrates a section profile P” of a profile similar to that of [Fig.5] except for its connection portion PC” which is devoid of a horizontal reinforcing flat rib such as NHPC and comprises a first central vertical reinforcing flat rib NVCPC extending at its median vertical plane between the upper and lower faces, as well as two other internal reinforcing flat ribs NVI PC and external NVEPC extending vertically and symmetrically to each other with respect to this median vertical plane each between the upper face and a corresponding inclined face PPC, so as to divide its internal cavity into four sub-cavities.

[0106] According to other variant embodiments not shown, the connection portion PC could comprise, for example, at least one flat reinforcing rib extending obliquely (i.e. neither vertically nor horizontally) between the two vertical side panels, between the upper and lower panels, or between the upper panel and one of the inclined panels PPC of the outer casing EPC.

[0107] It will also be noted that the profiles 111, 112 and 140 could also have an outer envelope of a different shape in section.

[0108] According to still other variant embodiments not shown, the lower ground clearance portion PGS could comprise at least one flat reinforcing rib extending between two opposite sides of its outer casing EPGs so as to divide its inner cavity into a plurality of sub-cavities.

[0109] [Fig.9] thus illustrates a section profile P”' of a profile similar to that of [Fig.5] with the exception of its connection portion PC”' whose external and internal overhangs DEPC and DI'”PC are not symmetrically identical: the internal overhang DF” PC is thus less wide than the external overhang DEPC while its lower lateral top is not bevelled.

[0110] In addition, the internal vertical reinforcing flat ribs NVIPC and external NVEPC are vertically aligned with the internal and external side panels of the upper sealing portion PSE and the ground clearance portion PGS.

[0111] Finally, it will be noted in support of [Fig. 10] illustrating a battery pack 1' integrating battery modules 200' different from those 200 of the battery pack 1 that the internal volume Vi of the chassis 100 according to the invention can be easily modulated to adapt to the reception of battery modules of different dimensions and / or oriented differently such as these modules 200', by adapting the lengths of the side members 111 and / or the cross members 112 and / or by modifying the number and / or the arrangement of reinforcing elements such as 140.

[0112] Many other variants are also possible and it will be recalled in this respect that the invention is not limited to the embodiments described and shown, but also encompasses all the variants of execution within the reach of those skilled in the art.

Claims

Claims

1. Chassis (100) for a motor vehicle battery pack (1, 1') comprising a rectangular frame (110) formed of two longitudinal side members (111) and two transverse cross members (112) fixed to each other at their ends, said side members (111) and said cross members (112) being constituted by metal profiles of the same section each comprising: - an upper sealing portion (PSE) extending vertically and having an upper face (FpSE) intended to receive in a sealed manner the peripheral periphery of an upper cover (800) of said battery pack (1, 1');and - a connection portion (PC, PC', PC”, PC”') extending below said upper sealing portion (PSE) projecting laterally on either side of the latter, respectively from an external lateral overhang DEPC and an internal lateral overhang DIPC on which are respectively intended to be fixed attachment supports (1100) to the underbody of said vehicle and battery modules (200, 200'); characterized in that each said profile also comprises a lower ground clearance portion (PGS) extending vertically below said connection portion (PC, PC', PC”, PC'”).;

2. Chassis (100) for battery pack (1, 1') according to claim 1, characterized in that said lower ground clearance portion (PGS) extends directly above said upper sealing portion (PSE) and over a width (lPGs) equal to that (1PSE) of this upper sealing portion (PSE).

3. Chassis (100) for battery pack (1, 1') according to one of claims 1 or 2, characterized in that said lower ground clearance portion (PGS) of each end (111 A) of a said side member (111) is assembled along a vertical welding plane with the lower ground clearance portion (PGS) of the corresponding end (112A) of a said cross member (112).

4. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 3, characterized in that said lower ground clearance portion (PGS) extends over a height greater than or equal to 10 millimeters.

5. Chassis (100) for battery pack according to one of claims 1 to 4, characterized in that said lower ground clearance portion (PGS) extends directly above said upper sealing portion (PSE) and over a width (lPGS) equal to that (1PSE) of this upper sealing portion (PSE).

6. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 5, characterized in that said lower ground clearance portion (PGS) comprises an outer casing of rectangular section (EPGS) forming its outer profile and defining an inner cavity.

7. Chassis (100) for battery pack (1, 1') according to claim 6, characterized in that said lower ground clearance portion (PGS) comprises at least one flat reinforcing rib extending between two opposite sides of its outer casing (EPGS) so as to divide its inner cavity into a plurality of sub-cavities.

8. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 7, characterized in that said external (DEPC) and internal (DIPC) lateral overhangs of said connection portion (PC;PC';PC”) are symmetrically identical with respect to the median vertical plane of said upper sealing portion (PSE).

9. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 8, characterized in that said connection portion (PC, PC', PC”, PC'”) comprises an outer casing (EPC) forming its outer profile and defining an inner cavity, said outer casing (EPC) having in section a beveled rectangle shape whose two lower lateral vertices are constituted by two inclined sides (PPG) forming with the horizontal an angle of inclination (0).

10. Chassis (100) for battery pack (1, 1') according to claim 9, characterized in that said angle of inclination (0) is between 15 and

11. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 10, characterized in that the upper sealing portion (PSE) of each end (11 IA) of a said side member (111) is assembled along a vertical longitudinal welding plane with the upper sealing portion (PSE) of the corresponding end (112A) of a said cross member (112).

12. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 11, characterized in that at least a part of the connection portion (PC, PC', PC”, PC'”) of each end (111A) of a said side member (111) is assembled along a vertical welding plane with a respective part of the connection portion (PC, PC', PC”, PC'”) of the corresponding end (112A) of a said crosspiece (112).

13. Chassis (100) for battery pack (1, 1') according to one of claims 1 to 12, characterized in that it also comprises at least one metal reinforcing element (140) extending longitudinally or transversely inside the frame (110) between the two said side members (111) or between the two said ribs (112) of this frame to which its two ends are fixed by welding.

14. Chassis (100) for battery pack (1, 1') according to claim 13, characterized in that each said reinforcing element (140) is made of a metal profile of section identical to that of said side members (111) and said cross members (112).

15. Battery pack (1, 1') intended to be fixedly installed against the underbody of a motor vehicle and comprising a chassis (100) and several battery modules (200, 200') mounted on this chassis (100); characterized in that said chassis (100) conforms to one of claims 1 to 14.

16. Motor vehicle comprising a battery pack (1, 1') according to claim 15.

Images