A vehicle frame provided with a containment pocket for a power supply unit

Abstract

A motor-vehicle frame (1) is described comprising: - a power supply unit (2) for propulsion of the vehicle, - a vehicle platform (5) and a pair of side members (6) longitudinally extending at the sides of the platform (5), - a containment pocket (4) for containing the power supply unit (2), extended under the platform (5) and having an access opening (8) to enable assembling of the power supply unit (2) inside the containment pocket (4), wherein said containment pocket (4) defines a containment space delimited above by the platform (5), laterally by the side members (6) and below by a further sheet element (7) spaced apart from the platform (5) and defining a general plane substantially parallel to the platform (5), - wherein said power supply unit (2) is provided with sliding means (10) configured to cooperate with a respective guide structure (9) arranged inside the containment pocket (4), in such a way that the power supply unit (2) is slidably mounted along a longitudinal direction of the vehicle within said containment pocket (4), through said access opening (8).

Description

[0001] “A vehicle frame provided with a containment pocket for a power supply unit”

[0002] ****

[0003] TEXT OF THE DESCRIPTION

[0004] Field of the invention

[0005] The present invention relates to a motor-vehicle frame comprising a platform, a pair of side members extending longitudinally at the sides of the platform, and a power supply unit for propulsion of the vehicle.

[0006] The power supply unit may comprise a battery assembly including a plurality of battery modules each having a plurality of battery cell clusters.

[0007] Prior art

[0008] The design of the battery assembly and the mounting on the vehicle are fundamental factors for the success of an electric motor-vehicle, such as an electric city car. It is in fact necessary to house a sufficient number of battery cells to ensure relatively high voltage and power supply, while - at the same time - identifying an arrangement of the battery cells that constitutes the most rational solution possible in terms of space occupied in the vehicle.

[0009] According to a now consolidated technique, the battery cells are rigidly connected to the platform of the vehicle, at specific reinforcement areas of the platform. One of the problems encountered in this solution is that, when the battery assembly is at this point obsolete, it is difficult to carry out maintenance and / or replacement of the battery assembly, therefore, in some cases having to scrap the entire vehicle even though it is generally still performing well.

[0010] The Italian patent N° 10 2019 000003015 in the name of the same Applicant illustrates a new configuration of an electric vehicle comprising a battery assembly slidably mounted, in a transverse direction with respect to the longitudinal direction of the vehicle, above the platform and within a cavity defined between the platform and a raised structure to support a vehicle seat.

[0011] However, this solution is not without some drawbacks, including having to specifically design the cavity for each different vehicle model, depending on the vehicle seat support structure arranged above the platform.

[0012] There is, therefore, a need to develop a modular and standardized solution, with reduced costs and a simple and intuitive assembly method, which makes the maintenance operations and replacement of the battery assembly extremely easy.

[0013] Object of the invention

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

[0015] More specifically, one object of the present invention is to produce a vehicle with an integrated power supply unit and relative extremely easy and intuitive assembly, maintenance and replacement operations.

[0016] An additional object of the invention is to propose a standardized vehicle architecture that allows a modular approach in the assembly of the power supply unit, without requiring major structural complications and significant cost increases.

[0017] Summary of the invention

[0018] In order to achieve one or more of the aforesaid objects, the invention relates to a motor-vehicle frame having the characteristics that are indicated in the attached claim 1 .

[0019] Further preferred characteristics and advantages are indicated in the dependent claims.

[0020] The invention is also directed at an assembly method as indicated in the attached claim 12.

[0021] Brief description of the figures

[0022] Further characteristics and advantages of the invention will become apparent from the description that follows with reference to the attached drawings, provided purely by way of non-limiting example, wherein:

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

[0024] - Figure 2 is a perspective view of the containment pocket illustrated in the previous figure,

[0025] - Figure 3 is an additional 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 battery assembly mounting method,

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

[0028] - Figure 6 is a partially exploded perspective view illustrating an additional step of the battery assembly mounting method,

[0029] - Figure 7A is an elevation view of the battery assembly mounted inside the containment pocket,

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

[0031] - Figure 8 is a partially exploded perspective view illustrating an additional step of the motor-vehicle frame mounting method,

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

[0033] - Figures 10-11 B are enlarged scale schematic views of some characteristics of the activation system of Figure 9,

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

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

[0036] Detailed description of more embodiments

[0037] In the following description various specific details are illustrated aimed at a thorough understanding of examples of one or more embodiments. The embodiments may be implemented 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 to avoid obscuring various aspects of the embodiments. The reference to “an embodiment” in the context of this description indicates that a particular configuration, structure or characteristic described in relation to the embodiment is included in at least one embodiment. Therefore, phrases such as “in an embodiment”, possibly present in different places of this description do not necessarily refer to the same embodiment. Moreover, particular conformations, structures or characteristics can be combined in a suitable manner in one or more embodiments and / or associated with the embodiments in a different way from that illustrated here, for example, a characteristic here exemplified in relation to a figure may be applied to one or more embodiments exemplified in a different figure.

[0038] The references illustrated here are only for convenience and do not therefore delimit the field of protection or the scope of the embodiments.

[0039] In the attached drawings, numeral 1 indicates - in its entirety - a motor-vehicle frame designed for housing a power supply unit 2 for the propulsion of the vehicle. In the following description and in the attached drawings, the power supply unit 2 is a battery assembly comprising a plurality of battery modules 3 each having a plurality of clusters of battery cells 3' which are arranged side-by-side, in a given direction, within a containment space. However, the present invention is equally applicable to the case wherein the power supply unit 2 is a hydrogen tank associated with a group of fuel cells.

[0040] For simplicity of discussion, below reference will always be made to the case wherein the power supply unit 2 is a battery assembly comprising a plurality of battery modules.

[0041] In a per se conventional manner, the motor-vehicle frame 1 comprises a platform 5 and a pair of side members 6, which extend longitudinally to the sides of the platform 5.

[0042] According to the present invention, the battery modules 3 are installed within a containment space of the motor-vehicle formed by a containment pocket 4 extended beneath the platform 5 of the motor-vehicle. More specifically, observing Figure 2 in particular, it can be noted that the containment pocket 4 is delimited by an upper wall defined by the platform

[0043] 5 of the motor-vehicle, two opposite side walls formed by the side members

[0044] 6 of the motor-vehicle, and a lower wall formed by an additional sheet metal element 7 spaced apart from the platform 5 and defining a general plane substantially parallel to the platform 5. It should, therefore, be noted that, compared to a conventional vehicle frame, to create the containment pocket 4 it is sufficient to prepare the additional sheet metal element 7 that defines the lower wall of the pocket 4.

[0045] According to an additional characteristic, the containment pocket 4 has a rear access opening 8 to allow the insertion of the battery modules 3 within the pocket 4. In one or more embodiments, the containment pocket 4 is completely open at the rear to allow the insertion of the battery modules 3 within the pocket 4, along the longitudinal direction of the vehicle frame 1 . It will, therefore, be appreciated that the containment pocket 4 is a frontally and laterally closed space (with reference to the vehicle frame), extended below the platform 5, and configured to house the battery assembly 2, which is inserted into the pocket 4 through the access opening 8.

[0046] According to an additional characteristic of the invention, as illustrated for example in Figures 3, 4, inside the containment pocket 4 there is a guide structure 9 configured to facilitate the assembly of the battery assembly 2 within the pocket 4. In fact, as described in detail below, the battery modules 3 comprise sliding means 10 suitable for cooperating with a respective longitudinal element of the guide structure 9, so that the modules 3 are slidably mounted along the longitudinal direction of the vehicle, through the aforesaid access opening 8.

[0047] The guide structure 9 comprises two side guides 9' extended along the opposite sides of the containment pocket 4 parallel to a respective side member 6. Each side guide 9' has an inner side surface configured to accommodate the sliding means 10 of the module 3, and to allow the sliding of the module 3 inside the pocket 4. The guide structure 9 also comprises a front cross-member 9" extended along the closed front surface of the containment pocket 4, and connected at its opposite ends to a respective side guide 9'. When the containment pocket 4 is completely empty, the first battery module 3 inserted in the pocket 4 will be able to slide along the side guides 9', up to a final position abutting against the front cross-member 9".

[0048] In one or more embodiments, the guide structure 9 also comprises a central guide 9" extended parallel to the side guides 9' in a substantially equally spaced position between them. The central guide 9" comprises two opposite side surfaces respectively facing towards a respective side guide 9', configured to accommodate respective sliding means 10 of the battery module 3. The sliding means 10 of the battery modules 3 may, therefore, comprise sliding elements provided on opposite sides of the outer surface of the battery module 3, configured to cooperate respectively with a side guide 9' and with the central guide 9". Thanks to the provision of the central guide 9", two side-by-side sliding passages are, therefore, created inside the pocket 4, for the assembly, along the respective sliding passage, of a sequence of battery modules placed side-by-side, until the pocket is filled 4. These modules will, therefore, have a width substantially corresponding to the distance (along the transversal direction of the frame 1 ) between a side guide 9' and the central guide 9".

[0049] Preferably, the guide structure 9 is made using extruded aluminum components fixed inside the containment pocket 4 by means of fixing means (for example rivets) which connect respective portions of the guide structure 9 to the structural elements forming the pocket 4. Alternatively, the side guides 9' may be made in one piece with the side members 6 of the vehicle.

[0050] In one or more embodiments, the guide structure 9, in addition to allowing the modules 3 to slide along the longitudinal direction of the vehicle frame 1 , ensuring alignment between the modules, also allows the battery modules 3 to be protected in the case of impact of the vehicle, thus increasing safety for passengers.

[0051] Figure 4 is a partially exploded perspective view wherein a step of the assembly process of the modules 3 within the pocket 4 is illustrated. Note that two adjacent pairs of battery modules 3 are already slidably engaged within the containment pocket 4, wherein each pair is axially inserted within a respective sliding passage; additional modules 3 must be assembled in the rear part of the containment pocket 4. Once all the battery modules 3 have been inserted, these are attached to the guide structure 9 with additional fixing means, so as to form a battery assembly 2 integrated with the guide structure 9 rigidly connected to the containment pocket 4. In the final installed configuration, the modules 3 are in contact with each other along the longitudinal direction of the vehicle. With the central guide 9", in the transversal direction, the modules 3 are adjacent to each other, but not in mutual contact, as they are arranged along the opposite sides of the central guide 9".

[0052] The number of battery modules 3 is defined for each new vehicle designed, depending on the available cell technology and the performance requirements of the vehicle itself. As indicated previously, the battery modules 3 comprise sliding means 10 arranged to cooperate with a respective longitudinal element of the guide structure 9.

[0053] 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 containment drawer structure defining a space for positioning the battery cells 3'. The tray 11 comprises a main support wall 1 T for positioning the cells 3' (illustrated in Figure 6B), a front wall, a rear wall opposite the front wall and two opposite side walls carrying the aforesaid sliding means 10 along their outer surface designed to cooperate with the guiding structure 9. Preferably, the sliding means 10 comprise one or more freely rotatable wheels arranged along opposed surfaces of the module 3, to cooperate with a respective element of the guide structure 9 (for example, a side guide 9' and the central guide 9"). Figure 6C illustrates the final configuration of the battery module 3, wherein an upper cover 12 is arranged above the cells 3', thus defining a closing surface parallel to the main support wall 11', and interfaced perimeterally with the side walls, front and back of the tray 11 . The battery cells 3' of each module 3 are, therefore, arranged inside a tray 11 equipped with a sliding mechanism capable of sliding along the longitudinal elements of the guide structure 9. Of course, the sliding means 10 may vary with respect to what is described above and illustrated in the drawings, creating other types of sliding elements well known to those skilled in the art (for example low-friction pads).

[0054] Further characteristics of the battery modules 3 are indicated below: Figure 7A is an elevation view of the battery assembly 2 mounted within the containment pocket 4 of the electric vehicle; Figure 7B is an enlarged scale view of one of the battery modules 3 installed on board the vehicle. To appreciate some details of the modules 3, in Figures 7A, 7B the modules 3 are illustrated without the closing covers 12. According to an additional illustrated characteristic, each tray 11 comprises centering elements 13 designed to guarantee the correct alignment and attachment of the modules 3 inside the containment pocket 4. For example, the centering elements 13 may be arranged along the front wall of the tray 11 , to cooperate with respective elements on the rear wall of another module already inserted in the pocket 4. Reference 14 also indicates one or more attachment brackets configured for receiving connection elements to stably fix the modules 3 to the guide structure 9 once positioned inside the pocket 4. In the illustrated example, the attachment brackets 14 protrude from the opposite side walls of the tray 11 to create a connection with respective portions of the side guides 9' and the central guide 9".

[0055] According to an additional characteristic of the invention, the frame 1 comprises an integrated thermal management system to manage the temperature of the battery assembly. The system is configured to manage the temperature of the batteries and keep it as constant as possible during operation, in order to optimize performance, heating or cooling the batteries depending on the operating conditions. The integrated system is designed to dissipate the heat generated or heat as needed, by circulating coolant or heating fluid through the battery modules 3.

[0056] Observing Figures 7A, 7B, note that each tray 11 comprises connection sockets 15 of the thermal management system to be connected to each other, to circulate the coolant along the battery assembly. Each tray 11 comprises a front connection socket and a rear connection socket protruding, respectively, from the front wall and the rear wall of the tray 11 , so that the front socket of a tray inserted in the pocket 4 can be connected to the rear socket of another tray already in place inside the pocket 4.

[0057] With reference to Figure 7A, the trays 11 that are inserted inside the pocket 4 when still empty, and arranged against the front cross-member 9", comprise at least one front socket connected to a coolant circulation duct 16. The duct 16 comprises an exchanger 32 operationally connected to a heating system mounted on board the vehicle, so as to allow the continuous circulation of coolant along the battery modules 3.

[0058] Observing Figure 7A it will therefore be appreciated that the integrated cooling system allows the circulation of coolant, along the battery modules 3, through the connection sockets 15 of the modules. Each module 3 comprises within it an integrated duct element placed in communication with the front and rear connection socket. Therefore, the battery modules 3 are already set up for the circulation of fluid, so as not to require the mounting of a specific circuit in addition to the size of the battery assembly. The circuit is closed with a duct 16 arranged in front of the modules 3 inside the pocket 4 which connects the inner circuit of the battery assembly, via said 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 with additional tubes or other hydraulic elements carried by the closing cover of the pocket 4, so as to close the circuit for circulating the coolant. In accordance with the embodiment illustrated in Figure 7A, in this rear part of the circuit there is a pump 34 for circulating the fluid and an expansion tank 33. The pump 34 and the tank 33 are in fluid communication with the rear sockets of the modules 3 which face the rear opening 8, via a further duct 35 equipped with at least one coupling 36 for filling / emptying the system. The circulation of fluid along the ducts is indicated with the illustrated arrows.

[0059] With reference to the specific configuration illustrated, the duct 16 comprises opposite ends connected, respectively, to a respective front socket 15 of two adjacent battery modules 3 arranged in the front part of the containment pocket 4.

[0060] These modules 3 are positioned along a respective insertion passage defined between the central guide 9" and a first side guide 9', and between the central guide 9" and a second side guide 9'.

[0061] In the event that the central guide 9" is not present and the modules 3 have a width substantially corresponding to the distance between the side guides 9', the front module arranged first inside the pocket 4 carries a pair of front connection sockets 15 to allow the connection of the duct 16.

[0062] According to an additional characteristic illustrated in particular in Figure 6, the guide structure 9 also comprises an assembly of auxiliary guides 20 spaced above the guide structure 9, inside a rear area 17 of the containment pocket 4. In fact, as illustrated in Figures 1 , 2, at this rear area 17, the platform 5 has a slightly curved upwards conformation. It will therefore be appreciated that the containment pocket 4 generally has a constant height determined by the spacing of the platform 5 and the further sheet metal element 7, and a rear area 17 with a greater height determined by the curvature of the platform 5.

[0063] The assembly of auxiliary guides 20 facing the rear access opening 8 comprises two opposite auxiliary side guides 20' joined by an auxiliary front cross-member 20". In one or more embodiments, the guide structure 9 comprises two side support arms 31 configured to laterally support the auxiliary guide structure 20 at a higher height than the side guides 9'. For each auxiliary side guide 20', a side support arm 31 is connected at its opposite ends to a respective side guide 9' and to the side guide 20'. Preferably, the side arm 31 extends substantially in an oblique direction, as the distance between the two auxiliary side guides 20' is smaller than the distance between the two side guides 20. In other words, the width of the containment space between the side guides 9' is greater than that between the auxiliary side guides 20'. It will therefore be appreciated that the side support arms 31 are configured to support the assembly of auxiliary guides 20 in a raised position with respect to the side guides 9'.

[0064] According to a preferred embodiment, the assembly of auxiliary guides 20 is configured only for mounting a service battery module 3" including a plurality of electronic components for operating the battery assembly 2, including one or more control units of the batteries, and a pump to control the circulation of coolant. Also for this module, there is a tray carrying the battery cells and including sliding means to slide the module along the auxiliary side guides 20', up to a position abutting against the auxiliary front cross-member 20".

[0065] In the final assembled configuration, the support surface of the service module tray 3" is not in contact with the upper surface of the modules 3 slidably mounted along the side guides 9'.

[0066] In the final assembled configuration, once the 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 an equipped cover supplied with components interfaced with the service module 3". As indicated previously, the containment pocket 4 is a frontally and laterally closed space which has a single rear access opening 8. Advantageously, to seal the battery assembly 2 inside the containment space it is, therefore, sufficient to carry out a seal limited to the perimeter of the closing cover 18.

[0067] In light of the characteristics described above, it will therefore be appreciated that the electric vehicle frame 1 comprises a platform 5 with an integrated guide structure 9 to receive a plurality of sliding trays 11 each forming a battery module 3. The guide structure 9 is arranged inside a closed containment space, which is an integral and structural part of the platform 5. The insertion of the battery modules 3 into the containment space occurs through an access opening 8, along the longitudinal direction of the vehicle.

[0068] Thanks to the set of characteristics described, the general configurations of the sliding trays 11 and the containment space allow standardizing and facilitating the assembly, maintenance, and replacement of the battery modules 3. The containment pocket 4 is configured to facilitate the rapid installation of the battery modules, with a portion of open surface limited precisely to allow the insertion of the battery modules 3 within the pocket 4.

[0069] An additional characteristic of the invention regards an activation system 19 of the electrical connection of the batteries, arranged to activate the electrical connection after positioning of the battery modules 3 within the containment pocket 4. In this regard, Figure 9 is a perspective view illustrating an embodiment of the activation system 19, and Figure 10 is an enlarged scale schematic view of some characteristics of the activation system 19.

[0070] According to a first characteristic, the activation system 19 of the electrical connection is formed by a single block of components comprising a screw-nut mechanism 19' and electrical contact blocks 21 to be connected to electrical contact portions 22 of the battery modules 3. The screw-nut mechanism 19' controls a vertical translation movement of the electrical contact blocks 21 for the connection with the electrical contact portions 22 of the batteries. This block of components is positioned inside the pocket 4, above the battery modules 3, and is arranged to be operated after the positioning of the battery modules 3, to activate the electrical connection of the battery assembly 2.

[0071] In one or more embodiments, the screw-nut mechanism 19' comprises an endless screw 23 extended inside the pocket 4 above the battery modules 3.

[0072] In one or more embodiments, the electrical contact block 21 comprises a plurality of conductive tracks 24, so-called bus bars, to be connected to the electrical contact portions 22 of the battery modules 3. In one or more embodiments, the screw-nut mechanism 19' comprises a transmission unit 25 operatively connected to the screw 23 and interfaced with the electrical contact block 21 , to control an approaching movement of the electrical contact block 21 following the rotation of the screw 23, until the connection is made between the conductive tracks 24 and the electrical contact portions 22 of the battery modules 3.

[0073] In accordance with what is illustrated in Figure 9, the screw 23 extends longitudinally along the containment pocket 4 above the modules 3 and supports a plurality of electrical contact blocks 21 spaced along the screw 23, with related transmission units 25, depending on the number and arrangement of the modules 3 within the pocket 4. For example, considering the arrangement of the modules 3 in Figure 9, each contact block 21 is configured to connect four battery modules 3 adjacent to each other (two for the first sliding passage and two for the second sliding passage).

[0074] In one or more embodiments, each contact block 21 comprises a conductive connection plane 21 ' extended parallelly above the modules 3, at the vertices of which the bus bars 24 are vertically extended in the direction of the upper face of the modules 3. In the deactivated position, the terminal ends of the conductive tracks 24 facing towards the modules 3 are spaced apart from the respective electrical contact portions 22 of the modules 3. In this regard, note that the upper covers 12 of each module 3 are equipped with special openings at the electrical contact portions 22, to enable contact with the respective conductive track 24.

[0075] With reference to the illustrated example, wherein the central sliding guide 9" is present, the screw 23 that supports the contact blocks 21 is mounted above the central guide 9", with the conductive tracks 24 extending vertically at the sides of the central guide 9", above respective electrical contact portions 22 of the modules 3.

[0076] With particular reference to Figure 10, in one or more embodiments, the transmission unit 25 comprises:

[0077] - a first transmission element 26 axially engaged with the endless screw 23, configured to translate along the longitudinal direction, integral with the rotation of the screw 23, wherein the first transmission element 26 is provided with a laterally protruding cam element 27,

[0078] - a second transmission element 29 that supports the conductive connection plane 2T and interfaced with the first transmission element 26, wherein the second transmission element 29 is equipped with a cam guide 30 wherein the cam element 27 can slide. The cam guide 30 is shaped to guide, through interaction with the cam element 27, a vertical lowering movement of the second transmission element 29 and, therefore, of the connection surface 2T of the contact block 21 to connect the conductive tracks 24 to the electrical contact portions 22 of the modules 3.

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

[0080] Before activating the rotation of the screw 23, the cam element 27 of the first transmission element 26 is inserted into an inlet portion of the cam guide 30 (Figure 11 A). In the final assembled configuration, the rear end of the screw 23 is positioned near the rear access opening 8, so that it can be easily rotated to activate the electrical connection, before closing the pocket 4 with the cover 18. In the illustrated embodiment, wherein the upper auxiliary guide structure 20' is present, the screw 23 remains accessible to the operator, despite all the battery modules being already installed, given that the support surface of the tray of the upper module is not in contact with the upper surface of the modules 3 slidably mounted along the side guides 9', thus defining a space within which the screw 23 extends.

[0081] During operation, following the rotation of the screw 23, the first transmission element 26 translates along the screw 11 and the second transmission element 30 carrying the contact block 21 is forced to lower towards the battery modules 3, due to the iteration between the cam element 27 and the cam guide 30 shaped with an oblique straight pattern (Figure 11 B). In the activated configuration, the lower contact surface of the bus bars 24 is electrically connected to the contact portions 22 of the modules (Figures 12C, 12D).

[0082] In light of the characteristics described, the electric vehicle frame 1 according to the invention provides an integrated battery assembly 2 and relative extremely easy and intuitive assembly, maintenance and replacement operations.

[0083] According to an aspect of the invention, the assembly method of the electric vehicle frame 1 includes the following steps:

[0084] - creating a vehicle platform 5 with integrated containment pocket 4;

[0085] - preparing a guide structure 9 inside the containment pocket 4;

[0086] - arranging an activation system 19 for the electrical connection of the batteries inside the pocket 4;

[0087] - sliding the battery modules 3 inside the containment pocket 4, along the guide structure 9;

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

[0089] - activating the electrical connection system 19;

[0090] - mounting a closing cover 18 configured to close the access opening 8 of the containment pocket 4;

[0091] - mounting the rear suspension of the vehicle.

[0092] Of course, to make the battery assembly 2 operational, it is necessary to carry out further battery assembly activation steps well known to those skilled in the art, such as for example the mounting of the "charge port" and the arrangement of the specific wiring for high voltage (HV).

[0093] Advantageously, the rear suspension of the vehicle may comprise a single suspension module comprising a cross-member at the ends of which the wheel assemblies extend. The cross-member is connected to the platform at one of its end areas, behind the containment pocket 4.

[0094] In one or more embodiments, the maintenance process determined by the previously described structure comprises: removing the rear suspension module, opening the rear cover 18, rotating the screw 23 to lift the contact block 21 , removing the obsolete modules 3.

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

Claims

CLAIMS1. A motor-vehicle frame (1 ) comprising:- a power supply unit (2) for propulsion of the vehicle,- a vehicle platform (5) and a pair of side members (6) longitudinally extending at the sides of the platform (5),- a containment pocket (4) for containing the power supply unit (2), extended under the platform (5) and having an access opening (8) to enable assembling of the power supply unit (2) inside the containment pocket (4), wherein said containment pocket (4) defines a containment space delimited above by the platform (5), laterally by the side members (6) and below by a further sheet element (7) spaced apart from the platform (5) and defining a general plane substantially parallel to the platform (5),- wherein said power supply unit (2) comprises sliding means (10) configured to cooperate with a respective guide structure (9) arranged inside the containment pocket (4), in such a way that the power supply unit (2) is slidably mounted along a longitudinal direction of the vehicle within said containment pocket (4), through said access opening (8).

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

3. A motor-vehicle frame (1 ) according to claim 2, wherein the guide structure (9) comprises a front cross-member (9") extending along a front surface of the containment pocket (4), and connected to its opposite ends to a respective side guide (9').

4. A motor-vehicle frame (1 ) according to claims 2 or 3, wherein said power supply unit (2) comprises a battery assembly including a plurality of battery modules (3) each having a plurality of battery cell clusters (3').

5. A motor-vehicle frame (1 ) according to claim 4, wherein the guide structure (9) comprises a central guide (9") extended parallel to the side guides (9') and placed substantially at equal distance between them, said central guide (9") comprising two opposite side surfaces configured to receive respective sliding means (10) of two adjacent battery modules (3).

6. A motor-vehicle frame (1 ) according to claims 4 or 5, wherein each battery module (3) comprises a cell tray (11 ) for placing the battery cells (3'), having a main support wall (11 ') for positioning the cells (3'), a front wall, a rear wall opposite to the front wall and two opposite side walls carrying the sliding means (10).

7. A motor-vehicle frame (1 ) according to claim 6, wherein each tray (11 ) comprises centering elements (13) configured to ensure correct alignment and fixing of the modules (3) inside the containment pocket (4).

8. A motor-vehicle frame (1 ) according to any of claims 4-7, wherein the guide structure (9) comprises an auxiliary guide assembly (20) spaced above the side guides (9'), within a rear area (17) of the containment pocket (4), wherein, at the rear area (17), the platform (5) has an upwardly curved shape.

9. A motor-vehicle frame (1 ) according to claim 8, wherein said auxiliary guide assembly (20) is configured for mounting a service battery module (3") including a plurality of electronic components for operating the battery assembly.

10. A motor-vehicle frame (1 ) according to claim 4, comprising an activation system (19) of the electrical connection of the battery assembly, arranged to activate the electrical connection after positioning the battery modules (3) within the containment pocket (4), wherein the activation system (19) comprises a single block of components positioned within the pocket (4) above the battery modules (3), including a screw-nut mechanism (19') and electrical contact devices (21 ) to be connected to electrical contact portions (22) of the battery modules (3), wherein the screw-nut mechanism (19') drives a vertical translation movement of the electrical contact devices (21 ) for connection with the electrical contact portions (22).

11. A motor-vehicle frame (1 ) according to claim 10, wherein the screw-nut mechanism (19') comprises an endless screw (23) extending along the longitudinal direction of the frame (1 ) above the battery modules (3), and a transmission unit (25) operatively connected to the screw (23) and interfaced to one respective electric contact device (21 ), configured for driving vertical movement of the contact device (21 ) following the rotation of the screw (23), the electrical contact devices (21 ) comprising a plurality of bus bars (24) to be connected to the electrical contact portions (22) of thebattery modules (3).

12. A method for assembling a motor-vehicle frame (1) according to any of the preceding claims, comprising the following steps:- providing the vehicle platform (5) with an integrated containment pocket (4),- mounting the guide structure (9) inside the containment pocket (4),- mounting the power supply unit (2) inside the containment pocket (4), along the guide structure (9),- activating the connection system (19), - mounting a closing cover (18) configured to close the access opening (8) of the containment pocket (4),- mounting a rear wheel suspension unit.

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