Chassis for a motor vehicle battery pack incorporating cooling circuit piping and battery pack comprising such a chassis

Abstract

The invention relates to a chassis for a motor vehicle battery pack comprising a rectangular frame having two longitudinal members (111) made of extruded metal profiles, each having at least one internal cavity (CPSE2) forming a circulation channel for the liquid cooling circuit of the battery pack, each said longitudinal member further having at least one transverse bore (APSE) made after the extrusion process from one of its lateral walls and opening into said channel, each said bore being in fluidic communication with a corresponding connection member (170) fixedly attached to said longitudinal member and having a sleeve (172) projecting from this longitudinal member, each said connection member also having a plate (171) having a bore in fluidic communication with said sleeve, said plate being fixedly and hermetically attached, by its face opposite said sleeve,against a lateral wall of said longitudinal member on the periphery of said bore. Figure to be published with the abbreviation: Fig. 7,

Description

Title of the invention: Chassis for a motor vehicle battery pack incorporating cooling circuit piping and battery pack comprising such a chassis 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. Previous technique

[0002] Electric-powered motor vehicles are becoming increasingly popular due to their reduced environmental impact, often lower operating costs, and constant 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, also encourage owners of motor vehicles with internal combustion engines to convert them into electric vehicles by integrating an electric drivetrain and a battery in place of the internal combustion engine and fuel tank.

[0004] Such a conversion, commonly referred to as "Automotive Retrofit", allows owners of older vehicles to continue using 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 electric motor vehicle classically comprises several battery modules each comprising a plurality of electrochemical cells capable of generating current by chemical reaction (these cells can for example be of the Li-ion type, of the Ni-Mh type, or Ni-Cd type).

[0006] These battery modules are mounted on a chassis to form a battery pack, more commonly known as a "battery pack," and are typically fixedly installed under the vehicle's underbody to avoid impacting passenger space while ensuring sufficient range. Such an installation is often mandatory for vehicles converted to electric propulsion, also known as "retrofitted" vehicles, where structural modifications must be limited for both cost and homologation reasons.

[0007] In order to be able to withstand very high mechanical stresses simulating frontal, rear or lateral collisions (in particular respecting longitudinal and transverse indentation criteria) in order to avoid any risk of short circuit or electrolyte leakage, the chassis of these battery packs may include an external frame made from several hollow profiled elements produced by an extrusion process in a metallic alloy (for example, based on aluminum) and assembled to each other by welding at their ends.

[0008] Commonly used in electric vehicles, lithium-ion type battery modules can overheat when subjected to fast charging conditions or high ambient temperatures.

[0009] To control the temperature of these battery modules, most battery packs installed in motor vehicles incorporate a cooling system in which a heat transfer fluid, generally water or a mixture of water and glycol, circulates through a cooling circuit. This fluid absorbs, via heat exchangers, for example of the "cold plate" type, arranged in contact with these battery modules, some of the heat generated by these modules and transports it to another heat exchanger in the vehicle, thus cooling it by transferring some of its heat to another cooling circuit, such as that of the vehicle's air conditioning system, to be dissipated into the ambient air.

[0010] Such a cooling circuit is classically made up of an assembly of several semi-rigid hot-formed pipes arranged around the periphery of the chassis, and extending along the underbody of the vehicle.

[0011] The installation of these pipes often proves problematic since they generally have to follow a tortuous path allowing them to bypass certain constituent elements of the vehicle installed on this body subframe.

[0012] Furthermore, these pipes must be fixed to this body base at several points by anchor clips, which also contributes to complicating the battery pack installation operations.

[0013] In order to overcome these problems, it is known from document DE 10 2020 101 018 Al that the two extruded metal profiles constituting the longitudinal members of the outer frame of the chassis each have at least one internal cavity forming a circulation channel for the cooling circuit of the battery pack and whose internal surface is covered with a thermally insulating layer.

[0014] Each longeron also has at least one transverse bore made after the extrusion process from one of its lateral walls and passing through a lateral internal cavity of this longeron before opening into this central internal cavity forming a circulation channel.

[0015] In each bore is further fixedly inserted (by force, by gluing and / or screwing) a connecting element equipped with a sleeve protruding from the corresponding longitudinal member and allowing a pipe to be connected to it smoothly.

[0016] Unfortunately, due to the small thickness of material traversed by each connecting element, the quality of the fixing proves insufficient to guarantee perfect sealing over time. Description of the invention

[0017] The present invention therefore aims to improve the situation.

[0018] For this purpose, it proposes a chassis for a motor vehicle battery pack comprising a rectangular frame formed of two longitudinal stringers and two transverse cross members fixed to each other at their ends, said stringers being made of extruded metal profiles each having at least one internal cavity forming a circulation channel for the liquid cooling circuit of the battery pack.

[0019] Each said spar further has at least one transverse bore made after the extrusion process from one of its lateral walls and opening into said circulation channel, each said bore being in fluidic communication with a corresponding connecting member fixedly attached to a said spar and having a sleeve projecting from this spar so as to allow a pipe to be fluidly connected to it.

[0020] According to the invention, each said connecting member also includes a plate having a drilling in fluidic communication with said sleeve, said plate being fixedly and in a sealed manner, by its face opposite said sleeve, against a lateral wall of said longitudinal member on the periphery of said bore.

[0021] The use of connecting elements equipped with such a plate makes it possible to obtain a better quality of fixing and sealing of these connecting elements to the longitudinal member and to limit very significantly the risks of leakage of the heat transfer fluid circulating in these circulation pipes.

[0022] According to a first preferred embodiment of the invention, said plate of each said connecting member is fixedly attached by screwing onto said side wall of said longeron, by means of screws passing through holes provided in said plate and screwing into corresponding tapped holes provided in said side wall of said longeron.

[0023] According to an advantageous construction associated with this first embodiment and allowing to limit the mass of the chassis, said screws advantageously open into the inside of two other internal cavities provided in each said longitudinal member respectively above and below said circulation channel.

[0024] In order to ensure a perfect seal between each connecting element and the corresponding spar according to this first embodiment, said plate of each said connecting member advantageously presents, on its opposite face to said sleeve and at the periphery of said drilling, an annular groove partially housing a sealing gasket coming under compression against said lateral wall of a said spar.

[0025] According to a second preferred embodiment of the invention, said plate of each said connecting member is fixedly attached by welding to said side wall of said longitudinal member, by means of a weld bead.

[0026] In order to ensure a perfect seal between each connecting element and the corresponding stringer according to this second embodiment, said weld bead advantageously extends continuously over the entire peripheral perimeter of said drilling.

[0027] In order to better preserve the original mechanical resistance characteristics of the welded materials, said weld bead is preferably produced by a friction stir welding process.

[0028] Generally, and in order to limit production costs, said sleeve of each said connecting element advantageously comes from a single block of material with said plate of this connecting element.

[0029] Alternatively, and in order to allow the use of different types of sleeves depending on the characteristics of the connecting fittings to be attached to them, said sleeve and said plate of each said connecting member may be made up of two separate pieces, said sleeve being attached fixedly and in a sealed manner by screwing onto said hole in said plate which is tapped.

[0030] In this case and in order to have a satisfactory screwing depth, the central area of ​​said plate in which said tapped hole is provided advantageously has a thickness greater than that of its peripheral area.

[0031] According to an advantageous configuration, a fluidic connection fitting is fixedly and securely attached to a first end of said circulation pipe of each said spar, while a plug is fixedly and securely attached to the second end of said circulation pipe of each said spar.

[0032] In order to limit heat loss, the inner surface of each said circulation pipe can be covered with a thermally insulating layer.

[0033] According to an advantageous construction ensuring excellent shock absorption, said longitudinal members and said cross members are made of metal profiles of the same cross-section, each comprising: - an upper portion of the seal extending vertically and in which the said circulation pipe is formed, this upper portion of the seal having an upper face designed to receive the perimeter in a watertight manner peripheral 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.

[0034] In order to protect the battery pack in the event, for example, of the vehicle being lifted with a trolley jack supported on the chassis frame or when the vehicle is crossing or descending curbs, each said profile may also advantageously include a lower portion of ground clearance extending vertically below said connection portion.

[0035] The invention also relates, in a second aspect, to a battery pack intended to be fixedly mounted against the underbody of a motor vehicle, said battery pack comprising such a chassis, several battery modules mounted on said chassis, and a cooling sub-assembly comprising a liquid cooling circuit through which a heat transfer fluid circulates, as well as several heat exchanger devices, each equipped with inlet and outlet nozzles. Each said inlet nozzle, respectively, outlet nozzle, is further fluidly connected to said sleeve of said respective connecting member fixed to a first, respectively, second, side member by means of a corresponding connecting pipe.

[0036] The invention finally relates, in a third aspect, to a motor vehicle comprising such a battery pack. Brief description of the drawings

[0037] The description of the invention will now be continued by a detailed description of several embodiments, given below by way of illustration but not limitation, with reference to the accompanying drawings, on which: - [Fig.1] represents an exploded perspective view of a battery pack for a motor vehicle comprising a chassis according to the invention; - [Fig.2] is a top view in mounted configuration of the battery pack of [Fig.1], on which some elements including the top cover have been omitted to facilitate reading; - [Fig.3] represents a view of the section of the profiled elements constituting the frame of the chassis of figures 1 and 2; - [[Fig.4]] is a cross-sectional view of the front end portion of the chassis of figures 1 and 2, taken along the vertical longitudinal plane EE of [Fig.2]; - [Fig.5] represents a cross-sectional view of the rear end portion of the chassis of figures 1 and 2, taken along the vertical longitudinal plane EE of [Fig.2]; - [Fig.6] is a cross-sectional view of the central portion of the chassis of figures 1 and 2, taken along the vertical longitudinal plane EE of [Fig.2]; - [Fig.7] represents a cross-sectional view of the left lateral portion of the chassis of figures 1 and 2, taken along the vertical transverse plane FF of [Fig.2]; - [[Fig.8]] is a perspective view of the connection area between an outlet nozzle of an exchanger device and the internal circulation pipe of a chassis side member of figures 1 and 2; - [Fig.9] represents a perspective view of one of the connecting elements screwed to the frame members that comprise the chassis of figures 1 and 2; - [[Fig. 10]] is a perspective view of a screwed connecting element according to an alternative embodiment; - [Fig. 11] and [Fig. 12] represent views similar to those of figures 7 and 8 but showing a chassis according to the invention whose connecting elements are welded to the frame members; - [Fig. 13] is a perspective view of one of the connecting elements welded to the frame rails of the chassis shown in Figures 11 and 12; and - [Fig. 14] is a perspective view of a welded connecting element according to an alternative embodiment. Description of the implementation methods

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

[0039] An orthogonal coordinate system XYZ is defined with respect to this battery pack 1, comprising three axes perpendicular in pairs, namely: - an X-axis, defining a longitudinal, horizontal direction, parallel to the ground and coinciding with the general direction of movement of the vehicle - a Y-axis, defining a transverse, horizontal direction, also parallel to the ground, which, together 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 frame defined above, the terms "longitudinal" or "longitudinally" shall refer to a direction parallel to the X axis, the terms "transverse" or "transversely" shall refer to a direction parallel to the Y axis, and the terms "vertical" or "vertically" shall refer to a direction parallel to the Z axis.

[0041] Furthermore, and by convention, the terms "lower", "upper", "front" and "rear" shall be understood in relation to the general orientation of the battery pack 1 in its Vehicle-mounted configuration. The terms "lower" and "bottom" indicate a closer proximity to the ground in the vertical direction than the terms "upper" or "high". The term "front" indicates a positioning facing the front of a vehicle in the horizontal direction, and the term "rear" indicates a positioning facing the rear of a vehicle in the same horizontal direction.

[0042] The terms "external" and "internal" will be used to define the relative position of an element with reference to the median vertical longitudinal plane of the battery pack 1. The element closest to this plane will thus be described as internal, as opposed to the other element further from this same plane, which will be described as external.

[0043] 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 200 battery modules fixedly mounted on this chassis 100; - a cooling sub-assembly comprising a liquid cooling circuit in which a heat transfer fluid circulates, generally water or a mixture of water and glycol, as well as several heat exchanger devices 300 each fixedly attached to the underside of a corresponding battery module 200; - a 400 power electronics box; - a 500 support bracket carrying this 400 power electronic box; - several electronic control systems for 600 battery modules and 200 batteries; - several rigid electrical connection braids 700 ensuring the high voltage electrical connection between the battery modules 200 and the power electronics box 400; - a top cover 800 covering the battery modules 200, the power electronics box 400 and the electronic control systems 600; - at least one 900V electrical outlet; and - two lower rectangular half-floors 1000 extending below the battery modules 200.

[0044] Housed in the internal volume Vi of the chassis 100, the battery modules 200, in this case two in number, each comprise a plurality of electrochemical cells capable of generating current by chemical reaction.

[0045] Each heat exchanger device 300, in this case of the cold plate type, comprises a metal plate 310 arranged in thermal contact with the lower face of a corresponding battery module 200 and covering a coil 320 in which circulates a coolant intended to absorb and dissipate the heat generated by this battery module 200.

[0046] Each coil 320 is provided with an inlet nozzle 321 and an outlet nozzle 322 projecting vertically above the corresponding plate 310 near one of its transverse edges.

[0047] 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 vehicle's electric drivetrain.

[0048] As illustrated by [Fig. 1], the support bridge 500 has two lateral legs 510 fixed by bolting to the internal lateral parts of the chassis 100 and an apron 520 overhanging the battery modules 200 and on which the power box 400 is fixed so as to keep it away from these battery modules 200.

[0049] Commonly referred to by the English acronym BMS for "Battery Management System", electronic control systems 600 ensure the balancing of the charges of all the cells of the same battery block 200 in order to prevent undervoltages or overvoltages.

[0050] Intended to ensure the electrical connection between the battery pack and the electric drive chain of the vehicle, the electrical connection socket(s) 900 are fixedly attached against an outer wall at the longitudinal end of the chassis 100.

[0051] Finally, the two half-floors 1000 made from cut sheet metal are fixedly and hermetically sealed against the chassis 100, each below a corresponding battery module 200 so as to protect it.

[0052] We will now describe in detail the chassis according to the invention 100 with reference to figures 1 to 3.

[0053] The chassis 100 comprises a rectangular metal frame 110 formed of two longitudinal stringers 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 1 and 2, the stringers 111 and the cross members 112 forming this frame 110 are made up of metal profiles having in section an identical profile P (see [Fig.3]) and obtained by a mechanical extrusion process from the same die.

[0055] With reference to this [Fig.3], each profile 111, 112 has a vertically oriented upper portion of PSE sealing and having an upper face FPSE against which the peripheral perimeter of the cover 800 is fixedly attached (typically by screwing or welding) and in a watertight manner (this sealing being obtained by means of a peripheral seal or a joining bead not shown and interposed between this upper face FpSE and this cover 800).

[0056] The upper portion of the PSE seal comprises an outer envelope of rectangular cross-section Epse forming its outer profile, as well as three in- cavities external CPSEi, CPSE2, CPSE3 arranged one above the other.

[0057] Advantageously presenting a circular section, the internal cavity CPSE2 is arranged in the central area of ​​this upper portion of the PSE seal between the two other upper cavities CPSEi and lower CPSE3 provided respectively above and below the latter.

[0058] The internal cavity CPSE2 of each longitudinal member 111 further forms a circulation channel for the cooling circuit of the cooling subassembly arranged to ensure the circulation of a heat transfer fluid along the chassis 100.

[0059] As illustrated by [Fig. 6], the upper PSE sealing portion of each longitudinal member 111 has several transverse APSE bores (in this case, two arranged in its central portion) made after the extrusion process from its internal side wall and opening into its CPSE2 circulation channel.

[0060] These APSE transverse bores are intended, as will be seen in more detail later, to allow the fluid connection of the inlet nozzles 321 and outlet nozzles 322 of the heat exchanger devices 300 to these CPSE2 circulation pipes.

[0061] Again with reference to [Fig.3], each profile 111, 112 also includes a horizontally oriented PC connection portion extending below the upper PSE sealing portion, 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 PSE sealing portion.

[0062] This PC connection portion is intended, on the one hand, to absorb most of the energy generated in the event of a collision in a longitudinal or transverse direction, and on the other hand, to allow the fixing of the battery modules 200 on the frame 110 as well as that of the cross members 112 of this frame 110 directly on structural elements of the vehicle's body underbody.

[0063] The PC connection portion comprises an outer casing EPC forming its outer profile and having in cross-section a beveled rectangular shape, the two lower lateral vertices of which are formed by two inclined planes PPC forming with the horizontal an angle of inclination θ 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 along a longitudinal or transverse direction, a portion of the longitudinal or transverse bending forces experienced by the profiles 111, 112 forming the frame 110 towards the lower part of this frame 110.

[0064] This PC connection portion also advantageously includes at least one flat reinforcing rib extending between two opposite walls of the outer EPC casing so as to delimit several cavities inside this outer EPC casing.

[0065] 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 along a longitudinal or transverse direction, so as to limit its bending curvature (these reinforcing ribs then absorbing part of the impact energy).

[0066] Such a structure thus makes it possible to limit the mass of the PC connection portion while allowing it to exhibit excellent mechanical resistance.

[0067] In this case and as illustrated by [Fig.3], the PC connection portion comprises a horizontal reinforcing flat rib NHPC extending at its median horizontal plane between the two vertical lateral panels of the outer EPC envelope, 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 portion of the PSE seal, so as to delimit six cavities inside this outer EPC envelope.

[0068] As can be seen in particular in figures 1 and 2, the external overhangs DEPC of the longitudinal members 111 are provided with bores through which hollow attachment studs 120 are welded around the perimeter of these bores and intended to ensure the attachment by bolting on the frame 110 of attachment supports not shown and allowing the battery pack 1 to be rigidly fixed against the underbody of the vehicle.

[0069] Still with reference to these figures 1 and 2, the external overhangs DEPC of the cross members 112 are also provided with bores through which hollow attachment studs 120 are welded around the perimeter of these bores and intended to ensure the bolting of these cross members 112 directly onto structural elements of the vehicle body underbody.

[0070] As can be seen in particular in figures 1 and 2, the internal DIPC overhangs of the cross members 112 are provided with bores on which nuts are crimped to ensure the fixing by bolting on the chassis 100 of a first longitudinal end of the battery modules 200 using screws.

[0071] Again with reference to [Fig.3], each profile 111, 112 finally includes a lower ground clearance portion PGS extending vertically below the connection portion PC.

[0072] This lower portion of the ground clearance PGS comprises an outer casing with a rectangular cross-section EPGS forming its outer profile and defining an inner cavity. In this case, it is devoid of a reinforcing rib.

[0073] 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 components such as the serpentines of the exchanger devices 300 and the electrical supply harnesses) in the event, for example, of the vehicle being lifted with a jack roller taking support on the frame 110 of the chassis 100 or when crossing or descending curbs by the vehicle.

[0074] As illustrated by figures 1 and 2, the ends 111 A, 112A of the stringers 111 and the cross members 112 are machined to fit together by complementary shape so as to allow their welding.

[0075] More specifically, the internal side wall of the upper PSE sealing portion of each machined end 11 IA of a longitudinal member 111 is assembled along a vertical longitudinal weld plane with the edge of the upper PSE sealing portion of the corresponding machined end 112A of a cross member 112.

[0076] Such a configuration makes it possible to achieve the sealing of the ends of these upper PSE sealing portions of the cross members 112 to which the electrical connection socket(s) 900 of the battery pack 1 are connected (such fluidic isolation of the upper PSE sealing portions of the cross members 112 with respect to those of the longitudinal members 111 making it possible to avoid any risk of short circuit).

[0077] As illustrated by Figures 1 and 2, the chassis 100 also preferably includes at least one metal reinforcement element 140 extending longitudinally or transversely inside the frame 110 between the two longitudinal members 111 or between the two ribs 112 of this frame to which its two ends are fixed by welding, so as to subdivide the internal volume Vi of the chassis 100 into several zones each housing at least one battery module 200.

[0078] This or these metal reinforcements 140 are advantageously made up of metal profiles having in section the same profile P (cf. [Fig.3]) as that of the longitudinal members 111 and the cross members 112 of the frame 110, so as to reduce the cost of development and manufacture 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).

[0079] In this case, and as can be seen in figures 1 and 2, the chassis 100 includes a single reinforcement 140 extending transversely between the two central zones of the frame longitudinals 111, and subdividing the internal volume Vi of the chassis 100 into two zones, each housing a battery module 200.

[0080] The internal DIPC and external DEPC overhangs of this transverse reinforcement 140 are provided with bores on which nuts 130 are crimped to ensure the bolting to the chassis 100 of the second longitudinal end of the battery modules 200.

[0081] It will also be noted with reference to figures 1 and 8 that these internal overhangs DIPC and external overhangs DEPC of the transverse reinforcement 140 are provided with oblong passage notches 141 through which the inlet nozzles 321 and outlet nozzles 322 of the coils 320 of the exchanger devices 300 pass.

[0082] It will also be noted that the four sides of the peripheral edge of the upper face of each rectangular half-floor 1000 are respectively fixedly and watertightly welded against the lower face of the internal overhang of a corresponding cross member 112, against the lower faces of the internal overhangs DI PC of the corresponding halves of the stringers 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 spray.

[0083] As illustrated by figures 1 and 2, the ends 140A of the transverse reinforcement 140 are machined to fit together by complementary shape on the central areas of the two longitudinal members 111 of the frame 110, so as to allow their welding.

[0084] As can be seen in particular on [Fig.4], a fluid connection fitting 150 is fixedly and securely screwed onto the threaded front end of the internal circulation pipe CPSE2 of each longitudinal member 111, these connection fittings 150 being intended to be fluidly and securely connected to unshown supply and discharge lines of coolant connected to another heat exchanger device of the unshown vehicle.

[0085] As illustrated in particular by [Fig.6], a plug 160 is fixedly and securely screwed onto the threaded rear end of the internal circulation channel CPSe2 of each longitudinal member 111.

[0086] The inlet nozzles 321 and outlet nozzles 322 of the various exchanger devices 300 are respectively fluidly connected to the internal circulation pipe C PSe2 of one and the other of the longitudinal members 111 by means of flexible connecting pipes 330 clearly visible in figures 7 and 8.

[0087] The fluidic connection between each connecting pipe 330 and the internal circulation pipe CPSE2 of a longitudinal member 111 is ensured by means of a fluidic connection element 170 fixedly attached to the upper sealing portion PSE of this longitudinal member 111 at the level of a bore APSE with which it is in fluidic communication.

[0088] Represented alone on [Fig.9], each fluidic connection member 170 comprises a plate 171 (in this case, rectangular in shape) having in its central part a circular hole 171A, as well as a sleeve 172 projecting from one of the faces of this plate 171 from the periphery of this hole 171A with which it is in fluidic communication.

[0089] As illustrated in Figures 7 and 8, the plate 171 is fixedly and securely attached, by its face opposite the sleeve 172, against the inner lateral wall of a longitudinal member 111 around the perimeter of an APSE- bore

[0090] Made from a single piece of material with the plate 171, the sleeve 172 allows, such as illustrated by figures 7 and 8, to connect fluidly a corresponding flexible conduit 330 by means of a fluidic connection fitting 331 provided at one end of this conduit 330 and fitting onto this sleeve 172.

[0091] In order to ensure the seal between the bore 171A of each connecting member 170 and the corresponding bore APSE, the plate 171 has, on its face opposite the sleeve 172 and at the periphery of this bore 171 A, an annular groove 17 IB partially housing a sealing O-ring 173 which is compressed against the internal lateral wall of the upper sealing portion PSE of a longitudinal member 111 on the periphery of this bore APSE (see [Fig.7]).

[0092] In order to allow its fixing by screwing to a longitudinal member 111, the plate 171 of each connecting member 170 has several orifices 171 C (in this case, four orifices arranged at the four corners of this plate) through which screws V are screwed into corresponding tapped holes PT visible on [Fig.6] and provided in the internal side wall of the upper sealing portion PSE of a longitudinal member 111 at the level of the upper cavities CPSEi and lower cavities CPSE3 (these screws V thus opening into the interior of these cavities CPSEi and CPSE3 as can be seen on [Fig.7]).

[0093] Fig. 10 illustrates an alternative embodiment of a screwed connecting member 170' in which the sleeve 172' and the plate 171' are made up of two separate parts, the sleeve 172' being fixedly and securely attached by screwing onto the bore 171'A of the plate 171' which is tapped.

[0094] In order to provide sufficient screwing depth to ensure optimal fixing quality between the sleeve 172' and the plate 171', the central area of ​​this plate in which the tapped hole 171'A is provided advantageously has a thickness greater than that of its peripheral area.

[0095] Such a configuration of the connecting element 170' thus allows the use of different types of sleeves depending on the characteristics of the connecting ends 331 provided at the ends of the flexible pipes 330.

[0096] Figures 11 and 12 illustrate another embodiment of the chassis according to the invention equipped with connecting members 180 welded to the longitudinal members 111.

[0097] Represented alone on [Fig. 13], each fluidic connection member 180 comprises a plate 181 (in this case, of circular shape) having in its central part a circular bore 181A, as well as a sleeve 182, made of material in one piece with the plate 181, projecting from one of the faces of this plate from the periphery of this bore 181A and onto which is fitted, as illustrated by figures 11 and 12, a connection fitting 331 provided at one end of a corresponding flexible conduit 330.

[0098] The plate 182 of each connecting member 180 is fixedly attached by welding against the internal side wall of the upper sealing portion PSE of a longitudinal member 111 on the periphery of a corresponding bore APSE.

[0099] Advantageously, this welding attachment is ensured by a weld bead produced by a friction stir welding process (commonly referred to by the Anglo-Saxon acronym FSW for "Friction Stir Welding") allowing the assembly of elements of considerable thickness (up to 80 millimeters) while ensuring better preservation of the original mechanical resistance characteristics of the welded materials.

[0100] This weld bead also preferentially extends continuously around the entire peripheral perimeter of the hole 181A in order to also ensure the seal between this hole and the corresponding bore APSE, which makes it possible to do without an annular groove such as 17 IB and a sealing gasket such as 173.

[0101] Furthermore, and in order to avoid any risk of crushing the internal side wall of the upper portion of the PSE sealing of the spar 111 during the making of the weld bead and due to the considerable pressure exerted by the welding pin against this wall, this upper portion of the PSE sealing may advantageously include, at the level of each of the upper cavities CPSEi and lower cavities CPSE3, at least one horizontal reinforcing flat rib NHPSE extending between the two side walls of its outer envelope Epse so as to divide this cavity into several superimposed sub-cavities (see [Fig. 11]).

[0102] Fig. 14 illustrates an alternative embodiment of a welded connecting member 180' in which the sleeve 182' and the plate 181' are made up of two separate pieces, the sleeve 182' being attached fixedly and in a sealed manner by screwing onto the bore 181'A of the plate 181' which is tapped.

[0103] In order to provide sufficient screwing depth to ensure optimal fixing quality between the sleeve 182' and the plate 181', the central area of ​​this plate in which the tapped hole 181'A is provided advantageously has a thickness greater than its peripheral area.

[0104] According to other unrepresented embodiments of the invention, the inner surface of each CPSE2 internal circulation pipe can be covered with a thermally insulating layer in order to limit heat loss.

[0105] Many other variants are also possible and it should be recalled in this regard that the invention is not limited to the embodiments described and represented, but also encompasses all variants of execution within the reach of a person skilled in the art.

Claims

Demands

1. A chassis (100) for a battery pack (1) of a motor vehicle comprising a rectangular frame (110) formed of two longitudinal members (111) and two transverse members (112) fixed to each other at their ends, said longitudinal members (111) being made of extruded metal profiles, each having at least one internal cavity (CPSE2) forming a circulation channel for the liquid cooling circuit of the battery pack (1), each said longitudinal member (111) further having at least one transverse bore (APSE) formed after the extrusion process from one of its lateral walls and opening into said circulation channel (CPSE2), each said bore (APSE) being in fluidic communication with a corresponding connecting member (170; 170'; 180; 180') fixedly attached to said longitudinal member (111) and equipped with a sleeve (172; 172'; 182;182') projecting from this longitudinal member (111) so as to allow a pipe (330) to be connected fluidly to it; characterized in that each said connecting member (170; 170'; 180; 180') also comprises a plate (171; 171'; 181; 181') having a bore (171A; 171'A; 181A; 181'A) in fluidic communication with said sleeve (172; 172'; 182; 182'), said plate (171; 171'; 181; 181') being fixedly and hermetically attached, by its face opposite said sleeve (172; 172'; 182; 182'), against a lateral wall of said longitudinal member (111) on the periphery of said bore (APSE).;

2. Chassis (100) according to claim 1, characterized in that said plate (171; 171') of each said connecting member (170; 170') is fixedly attached by screwing onto said side wall of said longitudinal member (111), by means of screws (V) passing through holes (171C) provided in said plate (171; 171') and screwing into corresponding tapped holes (PT) provided in said side wall of said longitudinal member (111).

3. Chassis (100) according to claim 2, characterized in that said screws (V) open into the interior of two other internal cavities (CPSEi, C PSE3) provided in each said longitudinal member (111) respectively above and below said circulation channel (CPSE2).

4. Chassis (100) according to claim 2 or 3, characterized in that said plate (171; 171') of each said connecting member (170; 170') has, on its opposite face to said sleeve (172; 172') and at the periphery of said drilling (171A; 171'A), an annular groove (171B) partially housing a sealing gasket (173) coming into compression against said lateral wall of said longitudinal member (111).

5. Chassis (100) according to claim 1, characterized in that said plate (181; 181') of each said connecting member (180; 180') is fixedly attached by welding to a said side wall of a said longitudinal member (111), by means of a weld bead.

6. Chassis (100) according to claim 5, characterized in that said weld bead extends continuously over the entire peripheral perimeter of said drilling (181A; 181'A).

7. Chassis (100) according to any one of claims 5 or 6, characterized in that said weld bead is produced by a friction stir welding process.

8. Chassis (100) according to any one of claims 1 to 7, characterized in that said sleeve (172; 182) of each said connecting member (170; 180) is made of material in one piece with said plate (171; 181) of this connecting member (170; 180).

9. Chassis (100) according to any one of claims 1 to 7, characterized in that said sleeve (172'; 182') and said plate (171'; 181') of each said connecting member (170'; 180') are made up of two separate pieces, said sleeve (172'; 182') being fixedly and securely attached by screwing onto said bore (171'A; 181'A) of said plate (171'; 181') which is tapped.

10. Chassis (100) according to claim 9, characterized in that the central area of ​​said plate (171'; 181') in which said tapped hole (171'A; 181'A) is formed has a thickness greater than that of its peripheral area.

11. Chassis (100) according to any one of claims 1 to 10, characterized in that a fluidic connection fitting (150) is fixedly and hermetically attached to a first end of said circulation pipe of each said longitudinal member (111), while a plug (160) is fixedly and hermetically attached to the second end of said circulation pipe (CPSe2) of each said longitudinal member (111).

12. Chassis (100) according to any one of claims 1 to 11, characterized in that the inner surface of each said circulation channel (CPSe2) is covered with a thermally insulating layer.

13. Chassis (100) according to any one of claims 1 to 12, characterized in that that said longitudinal members (111) and said cross members (112) are made up of metal profiles of the same section (P) each comprising: - an upper sealing portion (PSE) extending vertically and in which is provided said circulation pipe (CPSE2), this upper sealing portion (PSE) having an upper face (F pse) provided to receive in a watertight manner the peripheral perimeter of an upper cover (800) of said battery block (1); and - a connection portion (PC) extending below said upper sealing portion (PSE) projecting laterally on either side of the latter, respectively of an external lateral overhang (DEPC) and an internal lateral overhang (DIPC) on which are respectively intended to be fixed attachment supports to the underbody of said vehicle and battery modules (200).

14. Chassis (100) according to claim 13, characterized in that each said profile also comprises a lower ground clearance portion (PGS) extending vertically below said connection portion (PC).

15. Battery pack (1) intended to be fixedly mounted against the underbody of a motor vehicle, said battery pack (1) comprising a chassis (100), several battery modules (200) mounted on said chassis (100) and a cooling sub-assembly comprising a liquid cooling circuit in which a heat transfer fluid circulates and several heat exchanger devices (300) each provided with inlet nozzles (321) and outlet nozzles (322); characterized in that said chassis (100) conforms to any one of claims 1 to 14, each said inlet nozzle (321), respectively outlet nozzle (322), being fluidly connected to said sleeve (172; 172'; 182; 182') of said respective connecting member (170; 170'; 180; 180') fixed to a first, respectively second, said longitudinal member (111) by means of a corresponding connecting conduit (330).

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

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