Electric-vehicle frame provided with an integrated thermal-management system for managing the temperature of the battery assembly

Abstract

Described herein is a motor-vehicle frame (1) comprising: - a battery assembly including a plurality of battery modules (3) that each have a plurality of clusters of battery cells (3'); - a vehicle floor panel (5) and a pair of side members (6) that extend longitudinally at the sides of the floor panel (5); - a containment pocket (4) for containing the battery modules (3); and - a thermal-management system integrated with the battery modules (3), configured to manage the temperature of the modules (3) by heating or cooling the modules (3) according to the operating conditions by means of circulation of cooling or heating fluid through the battery modules (3).

Description

[0001] “Electric-vehicle frame provided with an integrated thermalmanagement system for managing the temperature of the battery assembly”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The present invention relates to an electric-vehicle frame comprising a floor panel, a pair of side members that extend longitudinally at the sides of the floor panel, and a power-supply unit for propulsion of the vehicle comprising a battery assembly that includes a plurality of battery modules each having a plurality of clusters of battery cells.

[0006] Prior art

[0007] Design of the battery assembly and assembling thereof on the vehicle constitute fundamental factors for success of an electric vehicle, such as an electric city car. In fact, it is necessary on the one hand to house a number of battery cells sufficient to guarantee a relatively high supply voltage and power, at the same time identifying an arrangement of the battery cells that will constitute the most rational possible solution in terms of space occupied in the vehicle.

[0008] According to a technique that is by now consolidated, battery cells are rigidly connected to the floor panel of the vehicle, in purposely provided reinforced areas of the floor panel. One of the problems encountered in this solution is that, when the battery assembly reaches the end of its service life, it is problematical to proceed to maintenance and / or replacement of the battery assembly, it being hence necessary in some cases to scrap the entire vehicle even though it is generally still in good working order.

[0009] The Italian patent No. 10 2019 000003015 filed in the name of the present applicant illustrates a new configuration of electric vehicle comprising a battery assembly that is slidably mounted, in a direction transverse with respect to the longitudinal direction of the vehicle, on the floor panel and within a cavity defined between the floor panel and a raised supporting structure of a seat of the vehicle.

[0010] The above solution is not, however, without certain drawbacks, amongst which the need to design purposely the cavity for each different vehicle model, according to the seat-supporting structure of the vehicle set on the floor panel.

[0011] There is hence felt the need of develop a modular and standardized solution, at reduced costs, and a simple and intuitive method of assembly, that will render extremely easy the operations of maintenance and replacement of the battery assembly.

[0012] There is moreover felt the need to develop a system for thermalmanagement of the battery assembly that will be perfectly compatible with a modular and standardized vehicle architecture provided with a compartment for mounting of the battery assembly, in so far as the solutions described in the documents LIS2018 / 108890, EP2266828, and DE 102018119544 are not fully satisfactory.

[0013] Object of the invention

[0014] The object of the present invention is to overcome the limits of the prior art.

[0015] More in particular, an object of the present invention is to provide a vehicle with integrated power-supply unit and corresponding operations of assembly, maintenance, and replacement that will extremely convenient and intuitive.

[0016] A further object of the invention is to propose a standardized vehicle architecture that will enable a modular approach to assembly of the powersupply unit, without involving major structural complications and considerable increases in cost.

[0017] Yet a further object of the invention is to propose a solution that will enable effective management of the operating temperature of the battery assembly, compatibly with a standardized vehicle architecture that will enable a modular approach to installation of the batteries.

[0018] Summary of the invention

[0019] With a view to achieving one or more of the aforesaid objects, the subject of the invention is a motor-vehicle frame having the characteristics that are specified in the annexed claim 1 .

[0020] Further preferred and advantageous characteristics are specified in the annexed dependent claims.

[0021] Brief description of the drawings

[0022] Further characteristics and advantages of the invention will emerge from the ensuing description, with reference to the annexed drawings, which are provided purely by way of non-limiting example and in which:

[0023] Figure 1 is a schematic side view of a motor-vehicle frame according to a preferred embodiment, which incorporates a containment pocket for a battery assembly;

[0024] Figure 2 is a perspective view of the containment pocket illustrated in Figure 1 ;

[0025] Figure 3 is a further perspective view of the motor-vehicle frame including a guide structure for mounting the battery assembly;

[0026] Figure 4 is a partially exploded perspective view illustrating a step of the method for assembling the battery assembly;

[0027] Figures 5A-5C illustrate a preferred embodiment of a battery module;

[0028] Figure 6 is a partially exploded perspective view illustrating a further step of the method for assembling the battery assembly,

[0029] Figure 7A is a view in elevation of the battery assembly mounted within the containment pocket;

[0030] Figure 7B is a view at an enlarged scale of one of the battery modules installed on board the vehicle;

[0031] Figure 8 is a partially exploded perspective view illustrating a further step of the method for assembling the frame of the vehicle;

[0032] Figure 9 is a perspective view illustrating a system for activation of the electrical connection of the batteries, according to one embodiment;

[0033] Figures 10 to 11 B are schematic views at an enlarged scale of some characteristics of the activation system of Figure 9;

[0034] Figures 12A and 12B are, respectively, a front view and a side view of the system for activation of the electrical connection, in a disconnected position; and

[0035] Figures 12C and 12D are, respectively, a front view and a side view of the system for activation of the electrical connection, in a connected position.

[0036] Detailed description of a number of embodiments

[0037] In the ensuing description, various specific details are illustrated aimed at enabling an in-depth understanding of examples of one or more embodiments. The embodiments may be provided without one or more of the specific details, or with other methods, components, materials, etc. In other cases, known structures, materials, or operations are not shown or described in detail so that various aspects of the embodiments will not be obscured. Reference to “an embodiment” or “one embodiment” in the framework of the present description is intended to indicate that a particular configuration, structure, or characteristic described in relation to the embodiment is comprised in at least one embodiment. Hence, phrases such as “in an embodiment” or “in one embodiment” that may be present in various points in this description do not necessarily refer to one and the same embodiment. Moreover, particular conformations, structures, or characteristics may be combined in any adequate way in one or more embodiments and / or associated to the embodiments in a way different from what is illustrated herein, so that, for example, a characteristic exemplified herein in relation to one figure may be applied to one or more embodiments exemplified in a different figure.

[0038] The references used herein are merely for convenience and hence do not delimit the sphere of protection or the scope of the embodiments.

[0039] Terms such as “side”, “lateral”, “back”, “rear”, “front”, “upwards” refer to a direction of advance of the vehicle when the frame of the vehicle is in the final assembled condition.

[0040] In the annexed drawings, the number 1 designates as a whole a motor-vehicle frame configured for housing a power-supply unit 2 for propulsion of the vehicle. In the ensuing description and in the annexed drawings, the power-supply unit 2 is a battery assembly comprising a plurality of battery modules 3 that each have a plurality of clusters of battery cells 3’ that are arranged alongside one another, in a given direction, within a containment space.

[0041] In a way in itself conventional, the motor-vehicle frame 1 comprises a floor panel 5 and a pair of side members 6, which extend longitudinally at the sides of the floor panel 5.

[0042] According to the present invention, the battery modules 3 are installed within a containment space of the vehicle formed by a containment pocket 4 extending underneath the floor panel 5 of the vehicle. In greater detail, in particular from Figure 2, it should be noted that the containment pocket 4 is delimited by a top wall defined by the floor panel 5 of the vehicle, two opposite side walls formed by the side members 6 of the vehicle, and a bottom wall formed by a further sheet-metal element 7 set at a distance from the floor panel 5 and defining a general plane substantially parallel to the floor panel 5. It should hence be noted that, as compared to a conventional motor-vehicle frame, to form the containment pocket 4 it is sufficient to provide the further sheet-metal element 7 that defines the bottom wall of the pocket 4.

[0043] According to a further characteristic, the containment pocket 4 has a rear access opening 8 to enable insertion of the battery modules 3 in the pocket 4. In one or more embodiments, the containment pocket 4 is completely open at the back to enable insertion of the battery modules 3 in the pocket 4, in the longitudinal direction of the motor-vehicle frame 1 . It will hence be appreciated that the containment pocket 4 is a space closed at the front and laterally (with reference to the motor-vehicle frame) that extends underneath the floor panel 5 and is configured to house the battery assembly 2, which is inserted in the pocket 4 through the access opening 8.

[0044] According to a further characteristic of the invention, as, for example, illustrated in Figures 3 and 4, provided within the containment pocket 4 is a guide structure 9 configured for facilitating mounting of the battery assembly 2 within the pocket 4. In fact, as described in detail in what follows, the battery modules 3 comprise sliding means 10 suitable for co-operating with a respective longitudinal element of the guide structure 9 in such a way that the modules 3 will be slidably mounted in the longitudinal direction of the vehicle, through the aforesaid access opening 8.

[0045] The guide structure 9 comprises two lateral guides 9’ extending along the opposite sides of the containment pocket 4 in a direction parallel to a respective side member s. Each lateral guide 9’ has an inner lateral surface configured to receive the sliding means 10 of the module 3 and enable sliding of the module 3 within the pocket 4. The guide structure 9 further comprises a front cross member 9” extending along the closed front surface of the containment pocket 4 and connected at its opposite ends to a respective lateral guide 9’. When the containment pocket 4 is completely empty, the first battery module 3 inserted in the pocket 4 can slide along the lateral guides 9’, up to a final position where it bears upon the front cross member 9”.

[0046] In one or more embodiments, the guide structure 9 further comprises a central guide 9” extending in a direction parallel to the lateral guides 9’ between them in a position substantially at the same distance from each of them. The central guide 9” comprises two opposite lateral surfaces that face, respectively, a respective lateral guide 9’, and are configured to receive respective sliding means 10 of the battery module 3. The sliding means 10 of the battery modules 3 may hence comprise sliding elements provided on opposite sides of the outer surface of the battery module 3 that are to co-operate, respectively, with a lateral guide 9’ and with the central guide 9”. Thanks to the provision of the central guide 9”, within the pocket 4 two sliding corridors are hence provided set alongside one another, for mounting, along the respective sliding corridor, of a sequence of battery modules set alongside one another, until the pocket 4 is filled. These modules will hence have a width substantially corresponding to the distance (in the transverse direction of the frame 1 ) between one lateral guide 9’ and the central guide 9”.

[0047] Preferably, the guide structure 9 is made up of extruded aluminium components fastened within the containment pocket 4 by fixing means (for example rivets) that connect respective portions of the guide structure 9 to the structural elements forming the pocket 4. Alternatively, the lateral guides 9’ may be made of a single piece with the side members 6 of the vehicle.

[0048] In one or more embodiments, the guide structure 9, in addition to allowing sliding of the modules 3 in the longitudinal direction of the motorvehicle frame 1 , thus guaranteeing alignment between the modules, also enables protection of the battery modules 3 in the event of impact of the vehicle, thus increasing passenger safety.

[0049] Figure 4 is a partially exploded perspective view illustrated in which is a step of the process of installation of the modules 3 in the pocket 4. It should be noted that two adjacent pairs of battery modules 3 are already slidably engaged within the containment pocket 4, where each pair is axially inserted within a respective sliding corridor. Further modules 3 are to be assembled in the rear part of the containment pocket 4. Once all the battery modules 3 have been inserted, they are fixed to the guide structure 9 with further fixing means so as to form a battery assembly 2 integrated into the guide structure 9 that is rigidly connected to the containment pocket 4. In the installed final configuration, the modules 3 are in contact against one another in the longitudinal direction of the vehicle. With the presence of the central guide 9”, in the transverse direction the modules 3 are adjacent to one another, but not in mutual contact, in so far as they are arranged along the opposite sides of the central guide 9”.

[0050] The number of battery modules 3 is defined for each new vehicle designed according to the cell technology available and to the performance requirements of the vehicle itself.

[0051] As indicated previously, the battery modules 3 comprise sliding means 10 configured to co-operate with a respective longitudinal element of the guide structure 9.

[0052] Figures 5A-5C illustrate a preferred embodiment of the battery modules 3. According to a first characteristic, the battery cells 3’ are arranged within a cell tray 11 (Figure 6A) having a drawer-operated containment structure that defines a space for positioning the battery cells 3’. The tray 11 comprises a main supporting wall 1 T for positioning the cells 3’ (illustrated in Figure 6B), a front wall, a rear wall opposite to the front wall, and two opposite side walls that carry, along their outer surface, the aforesaid sliding means 10 designed to co-operate with the guide structure 9. Preferably, the sliding means 10 comprise one or more freely rotatable wheels arranged along opposite surfaces of the module 3 for co-operating with a respective element of the guide structure 9 (for example, a lateral guide 9’ and the central guide 9”). Figure 6C illustrates the final configuration of the battery module 3, where a top cover 12 is set over the cells 3’, thus defining a closing surface that is parallel to the main supporting wall 1 T and interfaces perimetrally with the front and rear side walls of the tray 11 . The battery cells 3’ of each module 3 are hence arranged inside a tray 11 equipped with a sliding mechanism slidable along the longitudinal elements of the guide structure 9. Of course, the sliding means 10 may vary with respect to what has been described and illustrated above with reference to the drawings, providing other types of sliding elements well known to the person skilled in the sector (for example, low-friction slider pads).

[0053] Further characteristics of the battery modules 3 are indicated in what follows: Figure 7A is a view in elevation of the battery assembly 2 mounted within the containment pocket 4 of the electric vehicle; and Figure 7B is a view at an enlarged scale of one of the battery modules 3 installed on board the vehicle. To appreciate some details of the modules 3, in Figures 7A and 7B the modules 3 are illustrated without the closing covers 12. According to a further characteristic illustrated, each tray 11 comprises centring elements 13 configured to guarantee proper alignment and fixing of the modules 3 within the containment pocket 4. For instance, the centring elements 13 may be arranged along the front wall of the tray 11 to co-operate with respective elements on the rear wall of another module already inserted in the pocket 4. Moreover designated by the reference 14 are one or more fastening brackets that are to receive connection elements for stably fixing the modules 3 to the guide structure 9 once they are positioned within the pocket 4. In the example illustrated, the fastening brackets 14 project from the opposite side walls of the tray 11 to provide a connection with respective portions of the lateral guides 9’ and of the central guide 9”.

[0054] According to a further characteristic of the invention, the frame 1 comprises an integrated thermal-management system for managing the temperature of the battery assembly. The system is configured to manage the temperature of the batteries and maintain it as constant as possible during operation in order to optimize the performance by heating or cooling the batteries according to the operating conditions. The integrated system is provided for dissipating the heat generated or for heating according to the requirements, by means of circulation of cooling fluid or heating fluid through the battery modules 3.

[0055] From Figures 7A and 7B, it should be noted that each tray 11 comprises connection sockets 15 of the thermal-management system to be connected together to cause circulation of the coolant through the battery assembly. Each tray 11 comprises a front connection socket and a rear connection socket that project from the front wall and from the rear wall, respectively, of the tray 11 in such a way that the front socket of one tray inserted in the pocket 4 can be connected to the rear socket of another tray already in position within the pocket 4.

[0056] With reference to Figure 7A, the trays 11 that are inserted in the pocket 4 when the latter is still empty and are arranged against the front cross member 9” comprise at least one front socket connected to a duct 16 for circulation of coolant. The duct 16 comprises a heat exchanger 32 operatively connected to a thermal-management system mounted on board the vehicle so as to allow continuous circulation of coolant through the battery modules 3.

[0057] From Figure 7A it will hence be appreciated that the integrated cooling system enables circulation of coolant through the battery modules 3, via the connection sockets 15 of the modules. Each module 3 comprises inside it an integrated channelling element set in communication with the front and rear connection sockets. Consequently, the battery modules 3 are already pre-arranged for circulation of fluid so as not to require mounting of a purposely designed circuit that adds to the overall dimensions of the battery assembly. The circuit is closed with a duct 16 set in front of the modules 3 within the pocket 4, which sets in connection the circuit inside the battery assembly, via the aforesaid heat exchanger 32, with the thermal circuit of the vehicle. The rear connection sockets of the modules 3 that face the rear access opening 8 may be connected to further pipes or other hydraulic elements carried by the closing cover of the pocket 4 so as to close the coolant-circulation circuit. According to the embodiment illustrated in Figure 7A, present in this rear part of the circuit are a fluid-circulation pump 34 and an expansion reservoir 33. The pump 34 and the reservoir 33 are in fluid communication with the rear sockets of the modules 3 that face the rear opening 8, by means of a further duct 35 equipped with at least one filler 36 for filling / emptying the system. The fluid circulation along the ducts is indicated by the arrows represented in the figure.

[0058] With reference to the specific configuration illustrated, the duct 16 comprises opposite ends, each connected to a respective front socket 15 of two adjacent battery modules 3 arranged in the front part of the containment pocket 4. The above modules 3 are positioned along respective insertion corridors, one defined between the central guide 9” and a first lateral guide 9’ and the other defined between the central guide 9” and a second lateral guide 9’.

[0059] In the case where the central guide 9” is not present and the modules 3 have a width substantially corresponding to the distance between the lateral guides 9’, the front module that is set first inside the pocket 4 carries a pair of front connection sockets 15 to enable connection of the duct 16.

[0060] According to a further characteristic illustrated in particular in Figure 6, the guide structure 9 further comprises an auxiliary-guide assembly 20 set at a distance over the guide structure 9, within a rear area 17 of the containment pocket 4. In fact, as illustrated in Figures 1 and 2, in a region corresponding to this rear area 17, the floor panel 5 has a conformation slightly curved upwards. It will hence be appreciated that the containment pocket 4 has a generally constant height determined by the spacing between the floor panel 5 and the further sheet-metal element 7, and a rear area 17 with a greater height determined by the curvature of the floor panel 5.

[0061] The auxiliary-guide assembly 20 facing the rear access opening 8 comprises two opposite auxiliary lateral guides 20’ joined by a front auxiliary cross member 20”.

[0062] In one or more embodiments, the guide structure 9 comprises two lateral supporting arms 31 configured for supporting laterally the auxiliary guide structure 20 at a greater height than the lateral guides 9’. For each auxiliary lateral guide 20’, a lateral supporting arm 31 is connected at its opposite ends to a respective lateral guide 9’ and to the lateral guide 20’. Preferably, the lateral arm 31 extends substantially in an oblique direction in so far as the distance between the two auxiliary lateral guides 20’ is less than the distance between the two lateral guides 20. In other words, the width of the containment space between the lateral guides 9’ is greater than the width between the auxiliary lateral guides 20’. It will hence be appreciated that the lateral supporting arms 31 are configured for supporting the auxiliary-guide assembly 20 in a raised position with respect to the lateral guides 9’.

[0063] According to a preferred embodiment, the auxiliary-guide assembly 20 is configured only for installation of a service battery module 3” that includes a plurality of electronic components for operation of the battery assembly 2, amongst which one or more control units for control of the batteries, a pump 34, and an expansion reservoir 33 for controlling circulation of the coolant. Also for this module, a tray is provided carrying the battery cells, which includes sliding means for enabling the module to slide along the auxiliary lateral guides 20’ up to a position where it bears upon the front auxiliary cross member 20”.

[0064] In the final assembled configuration, the resting surface of the tray of the service module 3” is not in contact with the top surface of the modules 3 slidably mounted along the lateral guides 9’.

[0065] In the final assembled configuration, once insertion of the battery modules 3 within the containment pocket 4 has been completed, the containment pocket 4 is closed along the access opening 8 by positioning a closing cover 18 (Figure 8). Preferably, the closing cover 18 is a cover that is equipped with components interfaced with the service module 3”. As mentioned previously, the containment pocket 4 is a space closed at the front and at the sides that has a single rear access opening 8. Advantageously, to seal the battery assembly 2 inside the containment space it is hence sufficient to make a seal limited to the perimeter of the closing cover 18.

[0066] In the light of the characteristics described above, it will therefore be appreciated that the electric-vehicle frame 1 comprises a floor panel 5 with an integrated guide structure 9 for receiving a plurality of slidable trays 11 that each form a battery module 3. The guide structure 9 is set within a closed containment space that forms an integral and structural part of the floor panel 5. Insertion of the battery modules 3 in the containment space is performed through an access opening 8, in the longitudinal direction of the vehicle.

[0067] Thanks to the ensemble of characteristics described, the general configurations of slidable trays 11 and of the containment space make it possible to standardize and facilitate assembly, maintenance, and replacement of the battery modules 3. The containment pocket 4 is configured to facilitate fast installation of the battery modules, with an open surface portion limited precisely to allow insertion of the battery modules 3 into the pocket 4.

[0068] According to a further characteristic of the invention, the frame 1 comprises a system 19 for activation of the electrical connection of the batteries, configured to activate electrical connection after positioning of the battery modules 3 inside the containment pocket 4. In this connection, Figure 9 is a perspective view illustrating an embodiment of the activation system 19, and Figure 10 is a schematic view at an enlarged scale of some characteristics of the activation system 19.

[0069] The activation system 19 is configured both to activate the electrical connection of the batteries during production of the vehicle and to deactivate the electrical connection in order to proceed to maintenance or replacement of the battery assembly.

[0070] According to a first characteristic, the system 19 for activation of the electrical connection is formed by a single block of components comprising a screw-and-nut mechanism 19’ and electrical contact boards 21 to be connected to electrical-contact portions 22 of the battery modules 3. The screw-and-nut mechanism 19’ drives a movement of vertical translation of the electrical contact boards 21 for connection with the electrical-contact portions 22 of the batteries.

[0071] The above block of components is positioned within the pocket 4, above the battery modules 3, and is configured to be drive after positioning of the battery modules 3 to activate electrical connection of the battery assembly 2.

[0072] In one or more embodiments, the screw-and-nut mechanism 19’ comprises a wormscrew 23 extending within the pocket 4 above the battery modules 3.

[0073] In one or more embodiments, the electrical contact board 21 comprises a plurality of conductive paths 24, referred to as busbars, to be connected to the electrical-contact portions 22 of the battery modules 3.

[0074] In one or more embodiments, the screw-and-nut mechanism 19’ comprises a transmission assembly 25 operatively connected to the wormscrew 23 and interfaced with the electrical contact board 21 , for controlling a movement of approach of the contact board 21 following upon rotation of the wormscrew 23, until connection is made between the conductive paths 24 and the electrical-contact portions 22 of the battery modules 3.

[0075] In accordance with what is illustrated in Figure 9, the wormscrew 23 extends longitudinally along the containment pocket 4 above the modules 3 and supports a plurality of contact boards 21 set at a distance apart along the wormscrew 23, with corresponding transmission assemblies 25, according to the number and arrangement of the modules 3 inside the pocket 4. For instance, considering the arrangement of the modules 3 in Figure 9, each contact board 21 is configured for connecting four battery modules 3 adjacent to one another (two for the first sliding corridor and two for the second sliding corridor). Of course, the conformation of the contact board 21 may vary with respect to the one illustrated. In this perspective, for example, each transmission assembly 25 may support two contact boards set alongside one another, each carrying a pair of conductive paths 24.

[0076] In one or more embodiments, each contact board 21 comprises a conductive connection surface 2T extending in a parallel direction above the modules 3, at the vertices of which the busbars 24 extend vertically in the direction of the top face of the modules 3. In the de-activated position, the terminal ends of the busbars 24 facing the modules 3 are set at a distance from the respective electrical-contact portions 22 of the modules 3. In this connection, it should be noted that the top covers 12 of the modules 3 are purposely provided with openings in areas corresponding to the electrical-contact portions 22 to enable contact with the respective busbar 24.

[0077] In one or more embodiments, the busbars 24 comprise a cylindrical portion with a contact end configured for fast male-female connection with respective electrical-contact portions 22 of the modules 3. With reference to the example illustrated, where the central sliding guide 9” is present, the wormscrew 23 that supports the contact boards 21 is mounted above the central guide 9’, with the busbars 24 extending vertically at the sides of the central guide 9”, over respective electrical-contact portions 22 of the modules 3.

[0078] With reference in particular to Figure 10, in one or more embodiments, the transmission assembly 25 comprises: a first transmission element 26 axially engaging the wormscrew 23, configured for translating in the longitudinal direction, fixedly with respect to rotation of the wormscrew 23, where the first transmission element 26 is provided with at least one cam element 27 projecting laterally; and a second transmission element 29 that supports the conductive connection surface 2T and is interfaced with the first transmission element 26, where the second transmission element 29 is equipped with a cam guide 30 in which the cam element can slide 27. The cam guide 30 is shaped for guiding, via interaction with the cam element 27, a vertical movement of lowering of the second transmission element 29 and hence of the connection plane 2T of the contact board 21 for connecting the conductive paths 24 to the electrical-contact portions 22 of the modules 3.

[0079] Figures 12A and 12B are, respectively, a front view and a side view of the system 19 for activation of the electrical connection, in a disconnected position; Figures 12C and 12D are, respectively, a front view and a side view of the system 19 for activation of the electrical connection, in a connected position.

[0080] Before driving the wormscrew 23 in rotation, the cam element 27 of the first transmission element 26 is inserted in an entry portion of the cam guide 30 (Figure 11 A). In the final assembled configuration, the rear end of the wormscrew 23 is positioned in the proximity of the rear access opening 8 so that it can be easily driven in rotation to activate the electrical connection, prior to closing of the pocket 4 with the cover 18. In the embodiment illustrated, where the top auxiliary guide structure 20’ is present, the wormscrew 23 remains accessible to the operator, even though all the battery modules are already installed, given that the resting surface of the tray of the top module is not in contact with the top surface of the modules 3 that are slidably mounted along the lateral guides 9’, thus defining a space within which the wormscrew 23 extends.

[0081] In operation, following upon rotation of the wormscrew 23, the first transmission element 26 translates along the wormscrew 11 , and the second transmission element 30 carrying the contact board 21 is forced to descend towards the battery modules 3, on account of the interaction between the cam element 27 and the cam guide 30, which is shaped so as to have an oblique rectilinear profile (Figure 11 B). In the activated configuration, the bottom contact surface of the busbars 24 is electrically connected to the contact portions 22 of the modules (Figures 12C and 12D). Of course, by turning the wormscrew 23 in the opposite direction with respect to the one indicated above, the contact board 21 rises, disconnecting the busbars 24 from the respective modules 3.

[0082] In the light of the characteristics described, the electric-vehicle frame 1 according to the invention provides an integrated battery assembly 2 and corresponding operations of assembly, maintenance, and replacement that are extremely convenient and intuitive. The activation system 19 enables connection and disconnection of the battery assembly in a fast and intuitive way, without jeopardizing safety for the operators, who might otherwise come into contact with high-voltage components.

[0083] According to one aspect of the invention, the method of assembly of the electric-vehicle frame 1 comprises the following steps:

[0084] - providing a vehicle floor panel 5 with integrated containment pocket 4;

[0085] - providing a guide structure 9 within the containment pocket 4;

[0086] - providing within the pocket 4 a system 19 for activation of the electrical connection of the batteries;

[0087] - causing the battery modules 3 to slide within the containment pocket 4, along the guide structure 9;

[0088] - installing a service-battery module 3”;

[0089] - activating the electrical-connection system 19;

[0090] - filling with the conditioning fluid the cell-conditioning circuit;

[0091] - mounting a closing cover 18 designed to close the access opening 8 of the containment pocket 4; and

[0092] - mounting the rear suspension of the vehicle.

[0093] Of course, to render the battery assembly 2 operative, it is necessary to perform further steps of activation of the battery assembly that are well known to the person skilled in the sector, such as mounting of the charge port and pre-arrangement of the specific high-voltage (HV) wiring.

[0094] Advantageously, the rear suspension of the vehicle may comprise a single suspension module comprising a cross member extending at the ends of which are the wheel assemblies. The cross member is connected to the floor panel in its terminal area, behind the containment pocket 4. In one or more embodiments, the maintenance process required by the structure described previously comprises: removing the rear suspension module, opening the rear cover 18, turning the wormscrew 23 to raise the contact board 21 , and removing the modules 3 that are no longer serviceable.

[0095] Of course, without prejudice to the principle of the invention, the details of construction and the embodiments may vary widely with respect to what has been described and illustrated herein purely by way of example, without thereby departing from the scope of the present invention, as defined in the annexed claims.

Claims

CLAIMS1. A motor-vehicle frame (1 ) comprising:- a battery assembly including a plurality of battery modules (3) that each have a plurality of clusters of battery cells (3’);- a vehicle floor panel (5) and a pair of side members (6) that extend longitudinally at the sides of the floor panel (5);- a containment pocket (4) for containing the battery modules (3), which extends underneath the floor panel (5) and has an access opening (8) to enable assembling of the battery assembly within the containment pocket (4), wherein said containment pocket (4) defines a containment space delimited above by the floor panel (5), laterally by the side members (6), and underneath by a further sheet-metal element (7) set at a distance from the floor panel (5) and defining a general plane substantially parallel to the floor panel (5); and- a thermal-management system integrated with the battery modules (3), configured to manage the temperature of the modules (3) by heating or cooling the modules (3) according to the operating conditions, by means of circulation of cooling fluid or heating fluid through the battery modules (3),- wherein each battery module (3) comprises a cell tray (11 ) for placing the battery cells (3’), having a main supporting wall (11’) for positioning the cells (3’), a front wall, a rear wall opposite to the front wall, and two opposite side walls, each tray (11 ) comprising connection sockets (15) for circulation of cooling fluid, to be connected to the sockets (15) of another adjacent tray (11 ).

2. The motor-vehicle frame (1 ) according to claim 1 , wherein each tray (11 ) comprises at least one front connection socket and at least one rear connection socket that project, respectively, from the front wall and from the rear wall of the tray (11 ) in such a way that the rear socket of a first tray (11 ) inserted in the pocket (4) is connected to the front socket of a second tray (11 ) subsequently positioned inside the pocket (4), adjacent to the first tray (11 ) in the longitudinal direction of the pocket (4).

3. The motor-vehicle frame (1 ) according to claim 2, wherein a tray (11 ) inserted into the pocket (4) when the latter is still empty comprises at least one front socket connected to a connection duct (16) for circulation ofcooling or heating fluid.

4. The motor-vehicle frame (1 ) according to claim 1 , wherein each tray (11 ) comprises centring elements (13) provided for guaranteeing proper alignment and fixing of the modules (3) inside the containment pocket (4).

5. The motor-vehicle frame (1 ) according to any one of the preceding claims, wherein said battery modules (3) comprise sliding means (10) configured to co-operate with a respective guide structure (9) set within the containment pocket (4) in such a way that the battery modules (3) are slidably mounted in a longitudinal direction of the vehicle within said containment pocket (4), through said access opening (8).

6. The motor-vehicle frame (1 ) according to claim 5, wherein each tray (11 ) comprises one or more fastening brackets (14) that can receive connection elements for stably fixing the modules (3) to the guide structure(9) once they have been positioned inside the pocket (4).

7. The motor-vehicle frame (1 ) according to claim 5 or claim 6, wherein the guide structure (9) comprises two lateral guides (9’) extending along the opposite sides of the containment pocket (4) in a direction parallel to a respective side member (6), wherein each lateral guide (9’) has an inner lateral surface configured to receive the sliding means (10).

8. The motor-vehicle frame (1 ) according to claim 7, wherein the guide structure (9) comprises a central guide (9”) extending in a direction parallel to the lateral guides (9’) between them in a position substantially at the same distance from each of them, said central guide (9”) comprising two opposite lateral surfaces configured to receive respective sliding means(10) of two adjacent battery modules (3).

9. The motor-vehicle frame (1 ) according to claim 7 or claim 8, wherein the guide structure (9) comprises an auxiliary-guide assembly (20) set at a distance over the lateral guides (9’), within a rear area (17) of the containment pocket (4), wherein, in a region corresponding to said rear area (17), the floor panel (5) has an upwardly curved shape.

10. The motor-vehicle frame (1 ) according to any one of claims 5-9, wherein the guide structure (9) is made up of extruded aluminium components fixed inside the containment pocket (4) by fastening means that connect respective portions of the guide structure (9) to the vehicle floor panel (5) and / or to said further sheet-metal element (7).

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