CN112701413A

CN112701413A - Electromechanical connection structure of battery module in motor vehicle

Info

Publication number: CN112701413A
Application number: CN202011138385.XA
Authority: CN
Inventors: V·霍姆; H·赫滕
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2019-10-22
Filing date: 2020-10-22
Publication date: 2021-04-23
Also published as: DE102019216256A1; KR20210047803A; KR102420731B1

Abstract

The invention relates to an electromechanical connection of a battery module in a motor vehicle, in particular to an electrical energy store for a motor vehicle, comprising: a plurality of modules arranged next to one another, each comprising a module housing and at least one battery cell accommodated in the module housing, and each being connectable to a structural component of a motor vehicle; and-at least one connecting element releasably connecting two adjacent ones of the modules to each other; wherein the connecting elements are elastically deformable and are provided for generating a connecting force pressing the connecting modules towards each other as a result of the elastic deformation. The connecting elements here also connect the modules to one another in an electrically conductive manner. The invention further relates to a motor vehicle having an electrical energy store, to a connecting element and to a method for producing an electrical energy store for a motor vehicle.

Description

Electromechanical connection structure of battery module in motor vehicle

Technical Field

The invention relates to an electrical energy store (i.e. a store for electrical energy, such as a battery and in particular a traction battery). The energy store is provided for a motor vehicle and has at least one connecting element for a module of the energy store. The invention also relates to a motor vehicle and to a method for producing an electrical energy store for a motor vehicle. The motor vehicle can be, for example, a passenger car or a truck. In general, the motor vehicle can be driven at least partially or completely by means of electric energy, i.e. the traction energy can be generated by conversion of electric energy, for example by means of at least one electric traction motor.

Background

The use of modularly constructed electrical energy stores is known for motor vehicles and in particular for electrically driven motor vehicles. Modules, such as energy stores, can each comprise a plurality of battery cells. In order to be able to replace defective or insufficiently powerful battery cells, for production requirements or also for cost reasons, a plurality of modules which are small compared to the entire energy store are provided, each of which comprises a battery cell and a module housing which surrounds the battery cell. The modules are fixed to each other and/or to the carrier structure within the energy store.

For this purpose, it is known, for example, from DE 102017202354 a1 to connect adjacent modules to one another via form-fitting profiles (for example in the form of dovetail guides). DE 102017201710 a1 teaches a multi-part housing structure in which the individual housing plates are connected to one another and the battery cells are accommodated between them. DE 102016209853 a1 discloses a lower housing for accommodating a plurality of battery cells.

The recognition of the present inventors is that: known solutions do not always achieve a high cell density and thus an energy density of the energy store, since, for example, the connecting structure or the carrier structure takes up an undesirably large amount of space. Previous solutions do not always allow a cost-effective assembly and also disassembly (for example for maintenance purposes) of the battery cells or modules. Furthermore, previous solutions can be distinguished by inadequate crash behavior, for example because the connection structure of the module or the battery cell can be pressed into the module or the battery cell in the event of a crash.

Disclosure of Invention

The object of the present invention is therefore to improve an electrical energy store for a motor vehicle in order to avoid at least some of these disadvantages.

The object is achieved by the solution of the attached independent claims. Advantageous embodiments are given in the dependent claims. It goes without saying that all the above-described statements and features can also be applied to or provided in the present solution, unless stated or apparent otherwise.

The invention generally provides that the individual modules of the electrical energy store are fixed to one another by means of a connecting element (more precisely at least one connecting element). The connecting element can be a single connecting element, by means of which the modules are directly fixed to one another. Furthermore, the connecting elements are preferably elastically deformable and can press the modules towards one another or generate a restoring force when elastically deformed, which presses the modules towards one another and thereby holds them at one another.

As will be explained in more detail below, these connecting elements are also electrically conductive. The connecting elements enable an electrically conductive connection of the modules fixed to each other via the connecting elements. For example, the (high-voltage) connections of adjacent modules can be electrically connected to one another via connecting elements.

The electrical connections achieve functional integration. More precisely, the connecting element can also provide the function of an electrical connection in addition to a mechanical connection. Thereby, the possibility is provided to dispense with or at least simplify additional electrical connections between adjacent modules. This can lead to cost savings, but can also lead to space savings, in particular. The space that becomes free, which space was occupied by the high voltage connections between adjacent modules, can then be filled with battery cells. In addition to the reduced number of components, the possibility of increasing the energy density of the energy store is thereby also obtained, since fewer and/or smaller structural components are used for the electromechanical connection of the modules according to the invention.

Since the high-voltage connections to date are often positioned on the upper side of the energy store facing the vehicle floor, the vertical structural height of the energy store is also reduced accordingly (i.e. so-called Z-dimension chains, which correspond to the Z-axis of the vehicle height axis and/or generally to the vertical spatial axis).

The electromechanical functional integration also enables easier disassembly of individual modules, for example for maintenance purposes, by means of the disclosed connecting elements. According to the invention, only one component (connecting element) has to be disconnected and it is not necessary to additionally disconnect the separately provided electrical connection.

Generally, the electrical connection of the modules achieves that the modules are electrically connected together according to principles already known in the prior art. However, in contrast to previous solutions, such an electrical connection is provided via a connecting element which is likewise mechanically connected and preferably can withstand significant loads.

The elastic deformation can occur when the connecting element is inserted and can be maintained substantially permanently over the operating duration of the energy store (for example if no undesired external forces act on the modules, which press them toward one another and/or at least partially counteract the elastic deformation of the connecting element). Thereby, a preferably permanently applied connection force can be generated, but the connection force can also be changed, for example, depending on the relative movement of the modules. Alternatively, the connecting element can be substantially elastically undeformable, for example, in normal operation (in which no significant external forces act on the module). Elastic deformations, which cause the desired forces of the connecting element on the modules, can then occur, for example, when the modules are moved away from one another due to an external load. In this case, too, the connecting element can be elastically deformed in accordance with the relative movement and generate a corresponding counter force.

As is also explained in more detail below, the connecting element is preferably configured in the form of a clip or clip, for example because it comprises two clamping sections which preferably extend parallel and/or are positioned opposite one another. The connecting element and in particular its possible clamping sections can be at least temporarily elastically deformed, for example during assembly or during insertion into the electrical energy store, and then permanently maintain the deformation (or additionally deform in accordance with the relative movement of the connected modules) as explained above. Alternatively or additionally, the connecting element can first be undeformed after assembly and only elastically deformed as a result of the relative movement of the modules.

According to another aspect of the invention, it is provided that: the connection element comprises a displaceable part for generating the connection force. In this case, the connecting element can likewise be elastically deformable, but this is not mandatory. Alternatively, the displaceable member can be displaced (e.g., rotated or moved), preferably after being inserted into the void. In this way, in the preferably already installed or embedded state of the connecting element, the desired connecting force can be generated, for example, by clamping the module by means of the displaceable part.

In detail, the invention proposes an electrical energy store for a motor vehicle, comprising:

a plurality of (preferably parallel) modules arranged next to one another, each comprising a module housing and at least one battery cell accommodated in the module housing, and each being connectable to a structural component of a motor vehicle; and

at least one connecting element which releasably connects two (immediately or directly) adjacent ones of the modules to one another;

wherein the connecting elements are elastically deformable (at least temporarily, for example temporarily, during assembly or as a result of relative movement of the modules, or nevertheless permanently, for example by spreading apart during assembly) and are provided for, as a result of the elastic deformation, generating a force pressing the connecting modules towards one another (or in other words towards one another and/or towards one another),

and wherein the connecting element is further provided for electrically conductively connecting the modules to one another.

The electrically conductive connection can be provided, for example, by the connecting element providing or forming an electrically conductive connection path between the modules, in particular by providing an electrically conductive connection between sections (contact sections) of the connecting element which can be brought into contact with the modules in each case.

The connecting element can thus be at least partially electrically conductive. As explained below, however, the connecting element is preferably electrically insulated from the surroundings and/or the module housing. Instead, the connecting element can project into the module and more precisely into the module housing and there be electrically conductively contacted with the contact points of the module (for example by means of contact sections of the connecting element explained below).

According to one embodiment, the connection element forms an electrically conductive plug connection with a contact point inside the module or inside the module housing.

On the other hand, the connecting element is preferably provided for generating, as a result of the elastic deformation, a restoring force which counteracts a relative movement of the modules in which the distance between the modules is to be increased. The connecting elements are therefore generally provided for holding the modules at one another and/or limiting an increase in the spacing between the modules.

The elastic deformability can be achieved in a manner known per se via a suitable material selection (in particular a suitable metal material) and/or via a suitable structure or shape of the connecting element. By means of these parameters, it is possible, for example, to set a desired spring constant of the connecting element or, in general, a desired elastic deformation behavior.

The connecting element is capable of connecting two immediately adjacent modules to each other (i.e. two modules, between which no other module is located). The connecting element can generally provide a releasable connection of the modules. The connecting element can be tool-free to be placed and/or tool-free to be removed. However, according to one embodiment, the connecting element has a receiving structure for a tool (e.g., a threaded rod) or an engagement structure (e.g., a threaded hole), in order to facilitate removal, among other things.

The modules can be releasably fastened to one another at both ends of the vehicle body structure. For example, the modules can be fastened to frame-like regions of the body structure and/or connect opposing regions of the body structure to one another. For the fixing, a screw fastening can be provided, for example. The structural component can be a component that is a constituent part of the body structure of a motor vehicle. The structural member can thus be provided for absorbing loads and/or for carrying further components. For example, it can relate to (component parts of) frame-like components or generally to carriers.

Preferably, each module is connected at its immediate neighboring module via at least one connecting element of the type described herein. In general, different types of connecting elements can also be provided, i.e. connecting elements which can be electrically conductive but also non-electrically conductive, but which preferably have the elastic deformability disclosed here. Immediately adjacent modules can be connected via at least one electrically conductive connecting element, but also via at least one non-electrically conductive (but preferably elastically deformable) connecting element.

The at least one electrically conductive connecting element is preferably centrally positioned and is positioned, for example, close to or directly in the region of a vehicle longitudinal axis which extends through a middle plane of the vehicle and in the longitudinal direction of the vehicle (i.e. from the back to the front). The electrically conductive connecting elements are preferably arranged in any case at the locations of the module interior where the connection regions, contact points and, in particular, so-called intermediate connection pieces are provided. While the non-conductive connecting elements can be positioned off-center and/or near the outer ends of the modules. In particular, two non-electrically conductive connecting elements can receive or enclose an electrically conductive connecting element between them (for example, viewed in the transverse direction of the vehicle).

In general, each type of connecting element can be positioned in the region between the module ends and in particular between the housing ends thereof. At least one of the connection elements (then preferably the electrically conductive connection element) can be positioned substantially centrally between the mentioned ends.

The modules can extend (when the electrical energy store is installed in the vehicle) transversely to the longitudinal axis of the vehicle and/or in a horizontal plane. The connecting elements can be oriented substantially vertically and/or introduced vertically for the purpose of installation, for example, into receiving structures or recesses of the modules. In particular, the gap can extend mainly (i.e. in the largest dimension) vertically.

In general, the connecting element (and preferably all possible connecting elements) is preferably embedded at the underside of the energy store facing away from the vehicle or facing the road surface. In this case, however, the connecting element can extend vertically upwards and project into or be inserted there into the module or the module housing.

According to a preferred embodiment, the connecting element comprises at least two electrical contact sections, which can each be brought into electrically conductive contact with one of the modules. In particular, it is possible for the first contact section to be able to make electrically conductive contact with a first one of the modules, while the second contact section is able to make electrically conductive contact with a second one of the modules (i.e. the contact section is able to make contact with a different one of the modules which are preferably immediately adjacent). The contact section can also be referred to as a contact finger. Elongated and/or cylindrical sections can be involved. The contact section can project from the base body of the connecting element and in particular from a clamping section of a possible connecting element described below. In the state of being embedded in the energy store, the contact section preferably extends in the vertical direction (i.e. protrudes vertically upwards from, for example, the clamping section). This design allows a simple production of the plug connection and a simple manual assembly of the connecting element.

The contact points and/or coupling regions of the modules (preferably in the module housing) with which the contact sections of the connecting elements come into contact can be high-pressure coupling parts. It can comprise a recess, an opening, a bore or a general receiving structure into which the contact section can be introduced and/or can be received, respectively. A positive fit between the contact point/coupling region and the contact section of the connecting element introduced into the contact point/coupling region can thus preferably be established within the module. In this way, a reliable electrically conductive connection can be established by simple (preferably manual) insertion.

One development provides that the connecting element is clip-shaped and/or comprises at least one clamping section, wherein preferably the orientation of the connecting element can be changed when the connecting element is elastically deformed. Preferably, one of the contact sections is arranged here at each clamping section, and more precisely, one of the contact sections extends from one clamping section. In particular, two clamping sections can be provided, the orientation of which relative to one another can be varied within the elastic deformation range. Therefore, the connecting element can also be referred to as a connecting clip. Advantageously, such a connecting element enables a connection of adjacent modules that is as rigid as possible in order to minimize relative movements.

In particular, the connecting element can comprise at least two limbs (sometimes called legs) or (in other words) clamping sections which extend preferably parallel to one another at least in the undeformed state. Due to the elastic deformation, the spacing and in particular the angle between the edge portions/clamping sections can be increased. The connecting element can therefore expand as a result of the elastic deformation in general, in particular if it is configured in the form of a clip.

The edge portions/clamping sections can be connected to one another via a connecting section. The connecting section preferably extends in a substantially horizontal plane in the installed state of the connecting element. While the edge/clamping section and also the electrical contact section can run substantially vertically. Each edge/clamping section can be in contact with one of the modules and in particular the module housing. In particular, it can form-fit with the module or module housing and/or at least partially enclose the module or module housing. The clamping section can have a cutout, with which it can surround an edge region of the recess described here or, however, other contours of the module housing.

In principle, however, it is also possible to configure the edge/section substantially non-elastically deformable or, however, at least less elastically deformable than the other edge/section. The further section (which can then form the actual clamping section) can be pressed away from the first-mentioned section by elastic deformation.

The edge/clamping section and the contact section preferably arranged at the edge/clamping section can form an embedded section of the connecting element explained below without this being repeated individually in each case.

Advantageously, the contact section is electrically insulated with respect to the module housing. For example, the contact section can be not in electrically conductive connection with the module housing. Instead, the contact section can project from a non-conductive region of the connecting element, wherein the non-conductive region can be in contact with the module housing or can be supported at least at the module housing. In particular, the contact section can extend from the clamping section first in the region within the module housing, so that contact with the module housing (at least its outer side) can be reliably avoided.

According to one variant, a sealing element is provided, which is arranged on the module housing and/or the connecting element, for example as a separately actuatable component (e.g. a rubber sealing element) or as a sealing layer (e.g. a plastic layer). Alternatively or additionally, the seal is or can be arranged at an intermediate wall which separates possible hollow spaces of the module described below from one another, in particular in order to avoid moisture penetrating into the hollow space accommodating the battery cells.

The seal can protect the module housing interior and in particular the contact section preferably located there from moisture. Optionally, the seal can also be electrically insulating. Thus, according to one variant, an electrical insulation and sealing layer is provided, which extends at least in sections between the connecting element and the adjoining module, the module hollow space and/or the module housing. This prevents an undesired transfer of current from the connecting element or its contact section to the module housing.

Alternatively or additionally, the contact sections can be connected to one another by electrically conductive conductor sections, wherein the conductor sections are accommodated in the connecting element in an electrically insulated manner from the surroundings, at least in sections. In particular, the conductor section can comprise an electrical conductor and in particular a wire or cable. However, planar and/or inflexible conductor sections, i.e., conductors that are not necessarily cable-shaped, can also be involved. The conductor section can be inserted into and/or accommodated in the non-conductive base body and/or the connection section of the connection element.

In particular, it can be provided that the connecting element is electrically non-conductive except for the contact section and the conductor section and is made of plastic, for example. This also relates to the clamping section, but the clamping section can preferably be elastically deformable as before. At least those regions of the connecting element which are in contact with the contact section and/or the conductor section can be electrically non-conductive and are preferably made of plastic.

Overall, an undesired transmission of current from the contact section to the connecting element, in particular to an externally accessible region of the connecting element, is thereby avoided. In general, it is preferred that the contact sections and/or the possible conductor sections (or generally all current-conducting sections) are not accessible from the outside or are shielded by electrically non-conductive regions of the connecting element, at least in the embedded state of the connecting element. This improves safety and avoids an undesired outflow of current into the surroundings.

According to a further aspect, the contact section is releasably received in the connecting element and/or is thereby releasably connected. In particular, the contact section can be subsequently inserted into the connecting element to which the module has been connected. For example, the contact section can be pushed or can be pushed into a hole located in the connecting element. In general, the connecting element can have a preferably non-electrically conductive base body, which can surround the clamping segments and/or the connecting segments connecting the clamping segments, for example. The contact section can be releasably connected to the base body.

The releasable connection can simplify the assembly process, since the reception of the contact sections in the coupling in the module and the establishment of the mechanical connection via the connecting element do not have to be carried out simultaneously. Alternatively, the assembly tasks can be performed, so to speak, one after the other.

In particular, it can be provided in this connection that the contact section is formed on a threaded fastener (or as a threaded fastener) which can be inserted into the connecting element. The contact section can, for example, form a pointed or free end of the threaded fastener, which can be pushed into the module and in particular the module housing through the connecting element and/or a projecting base of the connecting element (for example through electrically conductive and mutually electrically connected bores). The threaded fasteners can then be receivable in threaded bores, wherein these threaded bores are electrically conductive and form a coupling region in the sense of the present disclosure. Thereby, a reliable electrical connection structure that can withstand mechanical loads can be established.

One embodiment provides that the connecting element (and in particular the base body of a possible connecting element) has an edge region which projects laterally beyond the contact section. In particular, the edge region can be in contact with and/or supported at least at least one of the module housings. The edge region can provide a stopping function and/or a centering function. In particular, the edge region can reduce the risk of the contact section accidentally coming into contact with the module housing or accidentally hitting the module housing during assembly or disassembly.

The edge region can form and/or be comprised by a base surface or an outer contour of the connecting element. The edge region can project laterally in a horizontal spatial plane and/or in a plane extending orthogonally to the longitudinal direction of the contact section. In particular, the edge region can define the maximum dimension of the connecting element and/or the contour of the connecting element in such a plane. In other words, the contact portion can be offset inward relative to the edge region or positioned closer to the geometric center of the connecting element.

According to a further embodiment, the module housings of the connected modules comprise in each case (at least) one recess into which in each case at least one section of the connecting element (for example the edge/clamping section together with the contact section arranged at the edge/clamping section) can be inserted. As mentioned, this enables, in particular, a vertical insertion or insertion of the segments. The voids of adjacent modules can be sized and/or positioned of the same type (e.g., at the same height). The recesses can be formed at edge regions lying opposite one another and/or generally at least partially at the underside of the respective module housing. The recesses can be combined to form a common and correspondingly larger free space or receiving space for the connecting elements.

In this case, it can also be provided that the inserted section rests against the inside of the respective module housing, except for the contact section of the connecting element. For this purpose, the module housing can, for example, provide an inner hollow space and/or the inserted section can be pushed from the outside into the inner hollow space of the module housing. The contact section can extend in the module housing to a connection region there and can preferably be pushed into the connection region in order to establish an electrically conductive connection.

According to one variant, the module housing has at least two preferably elongated hollow spaces or in other words chambers. The first hollow space, which is preferably relatively large in size, is used here for accommodating the battery cells. The second hollow space, which is preferably relatively small in size, is preferably largely or completely empty and serves as a deformation zone for the crash situation (for example when opening onto a ground level, such as a road pile). The hollow spaces can adjoin one another or be separated from one another via a common intermediate wall. When the energy store is installed in the motor vehicle, the second hollow space preferably points downward or forms the underside of the energy store and preferably also the underside of the entire motor vehicle (i.e. facing the road surface).

The recess of the module housing can be positioned in this respect in such a way that it extends into a second hollow space in which the clamping section can preferably be accommodated. However, the recess can also extend as far as into the first hollow space. The contact section can then be positioned there and brought into electrically conductive contact with the coupling region. In particular, the clamping section of the connecting element can be inserted into the second hollow space anyway and rest there, for example, on the inside of the second hollow space, but not into the first hollow space. This offers advantages in terms of the achievable energy density, since the first hollow space can be filled, for example, as far as possible with cells and/or the connecting element (at least the clamping section of the connecting element) does not form an interference contour there. Furthermore, the battery cells are protected against damage by the connecting element (or at least the clamping section of the connecting element) in the event of a displacement or movement of the connecting element in the event of a crash.

In summary, one embodiment of the invention provides that the module housing comprises at least two hollow spaces (according to each of the above-described variants) which are separated from one another (for example by an essentially closed or only partially through intermediate wall), wherein one of the hollow spaces accommodates the at least one battery cell. The clamping section of the connecting element can be positioned close to the further hollow space (or in other words closer to the further hollow space than the hollow space accommodating the one or more battery cells) and/or project at least partially into the further hollow space (for example into the described recess). The clamping section, however, cannot project into the first hollow space accommodating the battery cells, which preferably retains the electrical contact section if necessary. The hollow spaces can be arranged adjacently and/or in succession, in particular along the height axis of the vehicle (i.e. along the vertical space axis). The further hollow space is preferably positioned further below or below the first-mentioned hollow space.

The hollow space is preferably designed at least in sections with a cross-sectional profile which is largely or, however, completely closed, but can also have individual recesses, such as holes, or at least in sections, for example, with regions which are open on one side. The separation of the hollow spaces can be achieved via a (common) intermediate wall of the module housing, which intermediate wall preferably at least partially delimits two of the hollow spaces.

Furthermore, it can be provided that at least one of the inserted sections (connecting elements) is provided for a form-and/or friction-fit connection with the module housing (into the recess of which the section is inserted). This can be particularly suitable for the clamping section of the connecting element. In contrast, the contact section preferably does not make contact with the module housing, but at best with the (high-pressure) coupling region in the module housing.

In particular, structures such as projections, recesses or general engagement structures can be provided on the inside of the module or module housing, in which embedded sections (for example clamping sections) can be engaged for the purpose of forming a positive fit. While the abutment at, for example, the inner side can be sufficient to establish a friction fit. In this case, the segments can be shaped in the contact region to the inner wall (for example with serrations, teeth or tips).

By means of this variant, the holding of the connecting element is improved and the reliability of the established connection is thereby increased. In particular, an undesired removal or movement of the connecting element out of the recess can be avoided by a form fit and/or a friction fit.

Furthermore, according to one embodiment, it is provided that the section of the connecting element (connecting section) connecting the inserted sections is accessible from the outside (i.e. from outside the energy store and preferably without dismantling the energy store) and in particular lies against and/or runs at least in sections parallel to the outside of at least one of the module housings. This allows easy removability of the connecting element, for example, in order to remove the individual modules for servicing after the energy store has been installed in the vehicle. It is therefore also preferred that the connecting element is arranged on the underside of the energy store and/or of the motor vehicle in the installed state of the energy store. But does not exclude the possibility of the motor vehicle having a cover, for example a floor cover, which must first be removed.

One development provides that the connecting element comprises a recess, in particular a threaded bore, for receiving a tool (for example a threaded rod) for applying the removal force. The recess can in turn be accessible from the outside and is constructed in particular at the outside of the connecting element. The outer side can be the outer side of a connecting section of the connecting element. Overall, this enables an easy removal of the connecting element, for example in the case of a module which should be removed from the energy store for servicing.

The invention also relates to an electrical energy store for a motor vehicle, comprising:

a plurality of modules arranged next to one another, each comprising a module housing and at least one battery cell accommodated in the module housing, and each being connectable to a structural component of a motor vehicle; and

-at least one connecting element interconnecting two adjacent ones of the modules;

wherein the connecting element comprises a displaceable part which can be displaced for generating the connecting force. The connecting elements are again preferably provided for electrically conductively connecting the modules to one another.

All the above explanations and developments with the same features as the wording of the variant with a deformable connecting element also apply here to the present (displaceable) variants. In the present case, the connecting element can therefore also be elastically deformable, but this is not mandatory.

The displaceable member can for example be rotatable and/or movable. For this purpose, the displaceable part can be suitably fixed at the connecting element, for example by means of a swivel hinge (bolt). In particular, the displaceable part can establish a clamping contact or cause a clamping of the connecting element at the adjacent module as a result of the displacement.

For this purpose, the displaceable part can preferably come into contact with an inner wall of one of the module housings, for example as a result of the displacement, and in the event of further displacement then exert a clamping force on the module housing.

Opposite the displaceable part, a fixed (or rigid and/or non-displaceable) section of the connecting element is preferably provided, which section can serve as a kind of abutment. The fixed section can rest preferably against an inner wall of the respective other module (i.e. at the other module of the adjacent modules, at which the displaceable part is not supported next to or in contact with the other module). Due to the displacement, the spacing or intermediate space between the fixed region and the displaceable part can be reduced. Adjacent modules and in particular side walls of the modules can be accommodated at least partially in this intermediate space. Thus, the displaceable part can, as a result of its displacement, press the modules more and more towards each other and thereby clamp them against each other.

The displaceable part can be configured in a cam-like manner and/or be an eccentrically mounted rotatable part. The displaceable part can be rotatable and the described spacing of the intermediate space is reduced or reduced, for example, as a result of an eccentric bearing caused by the rotation.

The invention also relates to a motor vehicle with an electrical energy store according to one of the preceding aspects, wherein the modules are arranged parallel side by side in a receiving well of a body structure of the vehicle, and the module housings are detachably fastened to each other at both ends separately from each other at the body structure and are detachably connected to each other by means of the at least one connecting element in the region between the housing ends of the module housings.

The invention also relates to a connecting element for the electrically conductive connection of modules of an electrical energy store, wherein the connecting element is elastically deformable and comprises two clamping segments, the orientation of which relative to one another can be changed within the range of the elastic deformation, and wherein the connecting element comprises at least two electrical contact segments, which can each come into contact with one of the modules to be connected, with the electrical connection between the modules being established. In general, the connecting element can comprise each of the further features described herein in connection with the connecting element.

The invention also relates to a method for producing an electrical energy store for a motor vehicle, wherein the electrical energy store comprises a plurality of modules arranged next to one another, each comprising a module housing and at least one battery cell accommodated in the module housing, and each being connectable to a structural component of the motor vehicle; and wherein the method comprises:

-releasably connecting two adjacent ones of the modules with at least one connecting element;

wherein the connecting elements are electrically conductive and elastically deformable and are provided for generating, as a result of the elastic deformation, a connecting force pressing the connected modules towards one another.

The connection can be achieved by embedding the connecting element in the above-described void. In general, all the above and below variants, embodiments and explanations, in particular of the same device features, can also be applied to or provided in the method and the features of the method. For example, the method enables the production of an electrical energy store according to each of the embodiments described herein. For this purpose, all further method steps can be provided which are required for producing each of the energy stores described here and/or generally for providing each of the operating states or effects described here. The method can also include the step of elastically deforming the connecting element within the releasable connection range.

Drawings

Embodiments of the invention are explained below with the aid of the attached schematic drawings. Here, features of the same type or with the same function can be provided with the same reference numerals across several figures.

Fig. 1 shows a schematic illustration of a motor vehicle according to an exemplary embodiment of the present invention, with an electrical energy store according to a first exemplary embodiment of the present invention;

fig. 2 to 5 show partial views of the energy store in fig. 1 with a connecting element according to a first embodiment, and in fig. 3 the connecting element is provided as such a connecting element;

6-7 show partial views of an energy store according to the invention with a connecting element according to a further embodiment;

fig. 8 to 9 show partial views of an energy store according to the invention with a connecting element according to another embodiment.

Detailed Description

Fig. 1 shows the underside of a motor vehicle 1 according to an exemplary embodiment of the present invention with an electrical energy store 10 according to an exemplary embodiment of the present invention, wherein the energy store 10 is produced by means of a method according to the present invention.

The energy store 10 is a traction battery and stores electrical energy which can be converted by means of a traction motor, not shown, into traction force for the forward movement of the motor vehicle 1. In addition, further electrical consumers of vehicle 1, which are not used to generate traction force, such as air conditioners, infotainment systems or vehicle lighting, can also be supplied with electrical energy from energy store 10.

The motor vehicle 1 is shown in a strongly simplified manner. A front axle 2 and a rear axle 3 are seen, at which two vehicle wheels 4 are arranged in each case. The

axles

2, 3 are generally spaced from each other along the vehicle longitudinal axis L. Furthermore, a vehicle body structure 5 is shown. In the region between the

vehicle axles

2, 3, the vehicle body structure has a frame-like region 6 which delimits or delimits a receiving well 17 for the electrical energy store 10. The energy store 10 is fastened to two carriers 7 which are arranged opposite one another and extend substantially parallel to the vehicle longitudinal axis L, as is schematically illustrated by a cross-shaped fastening element 11 (for example a threaded fastener).

The energy store 10 comprises a plurality of, but in fig. 1, by way of example only four individual modules 12. Each of these modules has a module housing 14, which is illustrated in more detail in the other figures, in which a battery cell 13 (see fig. 3), which is only illustrated very schematically, is accommodated. Also not shown, each module 12 (or at least one module, however) has its own high-voltage connection, so that electrical energy can be taken from the cells of these modules 12 (or the at least one module), but electrical energy can also be supplied to the cells. For example, the high-pressure connection is provided for connection to a vehicle main line. Preferably, the high-pressure connection is integrated into the connecting clip described below. In any case, however, the modules 12 are electrically connected to one another by means of connecting clips in the manner explained below, whereby the modules are preferably connected in series.

The modules 12 extend parallel to one another and substantially transversely to the vehicle longitudinal axis L and are fixed at their two mutually opposite ends via the already described fixing elements 11 at the carrier 7, which is an example for a structural component. Preferably, the fastening is the only fastening of the module 12 at the body structure 5, wherein, however, a plurality of individual screw fastenings with the carrier 7 at both ends of the module 12 can be provided.

Furthermore, the modules 12 are arranged one behind the other along the vehicle longitudinal axis L. These modules each therefore have at least one module 12 immediately adjacent to it. Here, the modules 12 adjacent to one another are connected to one another by means of connecting elements 16, which are explained in more detail below. The connecting element 16 is schematically shown in fig. 1 as a simple dashed line. For the sake of clarity, not every connecting element 16 is provided with its own reference numeral, but only the connecting elements 16 of a selected adjacent pair of modules 12.

It is seen that one of the connecting elements 16 is positioned centrally (and preferably electrically conductive) and preferably on the vehicle longitudinal axis L. Two further connecting elements 16 are positioned on both sides of the central connecting element 16 and preferably on a half-way between the fixing element 11 and the central connecting element 16. The two further connecting elements can be electrically conductive or electrically non-conductive. All of the connecting elements 16 are preferably deformable in the manner described herein.

According to the invention and without limiting the same to further details of the embodiment, it is also possible for each pair of adjacent modules 12 to be provided with only one connecting element 16. The connecting element is then preferably a centrally located connecting element 16.

It is emphasized that the connecting element 16 is arranged at the underside of the energy store 10, which also forms the underside of the vehicle 1 and faces the observer in fig. 1. Alternatively, however, a bottom cover can also be provided. Furthermore, the modules 12 in fig. 1 are shown only by way of example at a slight spacing from one another along the vehicle longitudinal axis L. Preferably, the modules 12 bear against one another and are held in this position by the connecting element 16.

Fig. 2 shows a perspective view of a part of two adjacent modules 12. More precisely, a recess 24 is seen, which is formed in each module housing 14 and more precisely at its underside. In this case, the recesses 24 of adjacent module housings 14 merge into one another or define a common free space for accommodating one of the connecting elements 16, as explained below. The voids 24 are combined in the illustrated case, by way of example only, to form an oval void. Rectangular or circular shapes are also feasible.

In fig. 4, two adjacent modules 12 are shown in cross-sectional view. It is first of all seen that the module 12 and more precisely the module housing 14 are designed as elongated hollow profiles and preferably as extruded profiles. Here, the modules preferably have two hollow spaces or chambers 26. By way of example only, the dimensions of these hollow spaces or chambers are designed to be almost equally large in fig. 3. Preferably, the upper hollow space 26 is larger than the lower hollow space 26.

The lower hollow space 26 is located close to the underside of the electrical energy store 10 or faces the vehicle underbody. The lower hollow space serves as a deformation zone for crash situations, for example in which the vehicle 1 unintentionally opens onto a ground projection, such as a road pile.

The upper hollow space 26 serves to accommodate the schematically illustrated battery cells 13, which are protected against damage in the event of a crash by a deformation zone in the form of the lower hollow space 26. Furthermore, there is provided a coupling region 100 (for example a cylindrical bore) which can be a high-pressure coupling, for example. The coupling region 100 can form an electrically conductive plug connection with a contact section 102 of the connecting element 16, which is described below. At least some of the battery cells 13 of adjacent modules 12 can be conductively connected to one another in this manner.

Fig. 4 also shows the area of the recess 24 for receiving the connecting element 16, which is also shown and is shown in the inserted state. The void 24 extends from the underside of the module 12 or module housing 14 into a lower hollow space 26. Along the same vertical axis (i.e. concentric or overlapping with the interspace 24), in intermediate walls 104 separating the respective hollow spaces 26 of the modules 12 from each other, there are configured in each module 12 through-going portions (e.g. holes) 106. Through the passages 106, the elongated cylindrical contact sections 102 of the connecting elements 16 can each be introduced into the upper hollow space 26. The connecting element 16, however, does not project into the upper hollow space 26, except for the contact section 102. This reduces the risk of the connecting element 16 being supported on the battery cell 13, in particular in the event of a crash, and introducing significant forces there, which could lead to damage.

The connecting element 16 (which is shown in a single-part view in fig. 3) is of clip-like design. The connecting element has a horizontally extending connecting section 32 and two clamping sections (or edges) 30 which project at an angle from the connecting section. The latter extends at least partially vertically and thus projects into the recess 24 and in particular into the lower hollow space 26. Where it comes into abutment with the corresponding inner wall of the lower hollow space 26.

Starting from the clamping section 30, the elongated cylindrical contact sections 102 each extend in the vertical direction upwards (i.e. in the direction of the vehicle 1). The contact section is made of an electrically conductive material. The conductor sections 108, which electrically connect the contact sections 102 to one another, are also shown in dashed lines. Thereby, an electrically conductive connection is provided between the coupling regions 100 of adjacent modules 12 by the connecting element 16 via the contact section 102 and the conductor section 108.

The connecting section 32 and the clamping section 30 are surrounded in the example shown by a non-electrically conductive base body 110 (which is made of plastic, for example). The conductor sections 108 are accommodated in this base body 110 and are electrically insulated from the surroundings (for example injection-molded in the base body). The contact section 102 is exposed only within the module 12, as a result of which an undesired transmission of current to the surroundings can be prevented.

Not shown separately, the contact section 102 is inserted manually into the base body 110 and can be guided through the latter, for example as a screw-threaded fastener, and screwed into the coupling region 100. Preferably, an electrically conductive sleeve is then inserted into a bore in the base body 110 in order to also electrically conductively connect the contact sections 102 to one another via the connecting element 16. Alternatively, the contact section 102, however also the conductor spacing 108, is injection-molded into or through the base body 110.

Different electrically insulating seals or sealing layers 112 can be provided. For example, the seal or sealing layer can be applied to the inner wall of the passage 106 or arranged therein as a sleeve insert in order to prevent the current from flowing out of the contact section 102 into the module housing 14. If these seals 112 tightly surround the contact section 102, moisture is also prevented from passing into the upper hollow space 26.

The horizontal spacing a of the inner sides or ends of the clamping sections 30 facing each other is also depicted in fig. 4. In the unengaged state of the connecting element 16, this distance is smaller than the distance of the inner wall against which the holding section 30 is to be placed. In the illustrated case, this distance corresponds to the double wall thickness of the side walls of the module housing 14 that lie against one another. As a result, the clamping segments 30, when inserted into the recess 24 and after contact with the respective inner wall, are pushed apart from one another and thus spread the connecting element 16 as a whole. This results in an elastic deformation of the connecting element 16, so that an elastic restoring force F is generated which presses the clamping segments 30 towards one another. As a result, the clamping section 30 is pressed against the inner wall of the module housing 14 and produces a friction fit which prevents the connecting element 16 from falling out of the recess 24.

In particular, however, the restoring force F acts as a connecting force which presses the modules 12 toward one another and holds them together even during operation. As a result, the relative movement of the modules 12 relative to one another, in particular in the event of a crash, is limited without an increased risk of damage to the battery cells arising from the connecting elements 16. Even when the lower hollow space 26 is not provided and the connecting element 16 is arranged adjacent to the battery cell, the damage risk applies, for example, due to the elastic deformability of the connecting element itself. The connecting element 16 can, for example, be at least partially further elastically deformed in the event of a crash and/or at least slightly avoid the battery cell and thus not be pressed into the battery cell or only to a limited extent into the battery cell.

As already explained in the introduction, a significant restoring force F or connecting force F can also occur during operation, for example, when an increase in the (in particular horizontal) spacing of the modules 12 occurs. The elastic deformation of the connecting element 16 can then occur only very slightly during normal operation or during first use, for example in order to achieve retention only at the inner wall by means of a friction fit, but not in order to generate a significant and/or permanently applied connecting force F. It is also possible that no significant elastic deformation of the connecting element 16 occurs in the first place. The connecting element 16 can be held at the module 12 or in the module 12, preferably via a form fit as explained below.

Fig. 3 additionally shows: the base body 110 of the connecting element 16 has an edge region 114 which projects laterally outward with respect to each of the contact segments 102. This applies in particular in a (virtual) plane extending orthogonally to the longitudinal axis X of the contact section 102. The edge region 114 thus forms a lateral projection which, when introduced into the recess 24, can come into contact with the recess and/or be supported therein without the contact section 102 having to do this positively. As a result, an undesired collision of the module housing 14 with the contact section 102 can be avoided.

Finally, fig. 5 shows a part of the energy store 10 in partial and more precisely the underside of the energy store. In this case, the region of three adjacent modules 12 is seen, two immediately adjacent modules 12 being connected to one another by means of connecting elements 16 (i.e. the middle module is connected to the left module and the middle module to the right module). The recess 24 of fig. 2 and 3 is covered by a corresponding connecting section 32 of the connecting element 16 inserted into said recess.

Furthermore, an optional engagement structure 34 can be seen at the underside of the connecting element 16 facing the viewer or at the connecting section 32 of said connecting element. The engagement structure is a threaded hole into which a corresponding counterpart of a tool (e.g. a threaded rod) can be screwed. The connecting element 16 can thus be disengaged again from the module 12 by the easy application of a suitable removal force (for example a tipping force).

In the following fig. 6 to 9, further embodiments of the connecting element 16 are shown. Here, too, the contact sections 102 described above and the passages 106 between the hollow spaces 26 of the modules 12 are respectively depicted, which are described above with reference to fig. 3 and 4. These features are not discussed separately again below to avoid repetition.

An alternative embodiment of the connecting element 16 is shown in fig. 6 and 7, wherein the cross-sectional view shown is again similar to that in fig. 3. In particular, the connecting element 16 is again inserted into the recess 24 and rests against the (per se optional) inner wall of the lower hollow space 26.

In the case of fig. 6, a form fit is established between the connecting element 16 and each module or

module housing

12, 14. For this purpose, mechanical joints are formed between the elements mentioned. The inner wall of the module housing 14 and the connecting element 16 have corresponding engagement structures.

In the example shown, the connecting elements 16 preferably each comprise a recess 50 (for example in the form of a groove or a partial depression) at the inner sides of their mutually opposite clamping sections 32. Projections 52 of a corresponding design size are formed on the inner walls of the module housing 14. The projection can be accommodated in the recess 50 as a result of the insertion or insertion of the connecting element 16 and also in the case of the clamping sections 32 being at least temporarily elastically pressed away from one another. The reverse is also possible, wherein the projection at the clamping section 32 engages into the recess at the inner wall of the module housing 14.

However, similar to the discussion of fig. 4, it is also possible to permanently maintain the elastic deformation of the connecting element 16, for example by spreading the connecting element apart, even after the form fit has been established.

A possible solution for an improved (i.e. more effective or stronger) establishment of the friction fit is shown in fig. 7. For this purpose, a sawtooth-shaped structure 60 with a plurality of projecting sawteeth (i.e. pointed and/or pointed-edge-shaped projections) is shown in each case on the inner sides of the clamping segments 32 facing one another. The saw-tooth structure can lead to a relatively strong friction fit, for example by micro-bonding into the surface of the module housing 14, as an example in the case of fig. 3.

It is also possible to combine the variants of fig. 6 and 7 with one another (for example by means of correspondingly elongated clamping sections 32, which in turn can be said to have the structures 50, 60). Only one of the clamping sections 32 can also be configured according to the variant of fig. 6 and 7, and the other clamping section can be configured according to the other variant of fig. 6 and 7, or however according to the variant of fig. 4.

In addition, it is also possible in the case of fig. 6 and 7 for the connecting element 16, after insertion, to be initially not elastically deformed (for example as long as an undesired increase in the spacing of the module housing 14 does not occur), or to be able to be permanently elastically deformed, so to speak, in order to generate a correspondingly constantly acting connecting force.

Fig. 8 (which again contains a representation similar to fig. 4, 6 and 7) finally shows a further variant of a connecting element 16, which in turn engages in a recess 24 of an adjacent module housing 14 and rests against the inner wall of said recess. Fig. 8 illustrates the connecting element 16 in a perspective single part view.

The connecting element 16 of this variant need not be elastically deformable, but this can also be provided. The connecting element has a fixed (i.e. preferably generally non-deformable and/or non-displaceable) section 70. The fixed section is positioned at a first end of the connecting element 16. The displaceable member 72 is located at an opposite end of the connecting element 16. The displaceable member is cam-like configured. The displaceable part is rotatably supported via a pin 74 at the connecting element or at the base 71 of the connecting element. The base body 71 is generally rigidly designed and preferably designed in one piece with the fixed portion 70.

The axis of rotation R about which the displaceable part 72 can be rotated extends generally vertically as shown in fig. 8 and 9 and in particular transversely to the vehicle longitudinal axis L in fig. 1 (i.e. into the plane of the drawing).

Preferably, the displaceable part 72 is fixed in a rotationally fixed manner at the pin 74, and the pin 74 can be rotated, for example, via a not separately shown engagement structure 34 at the underside of the connecting element 16. For example, the engagement structure 34 can be realized as an internal thread in the peg 74 or as a hole configured with a non-circular cross-section. A correspondingly shaped or externally threaded tool can engage into the engagement structure 34 and rotate the pin 74, and thus also the displaceable part 72, so to speak from the outside. In particular, this allows the member 72 to be rotated afterwards even after it has been inserted into the recess 24.

Due to the shape of the displaceable part 72, however in particular due to the eccentric connection to the pin 74 which can be seen in fig. 9, the distance a of the opposing faces of the fixed portion 70 can be changed and in particular can be reduced as a function of the rotation of the part 72.

In this case, the distance a is preferably initially relatively large in order to insert the connecting element 16 into the recess 24 and to be able to accommodate the wall of the module housing 14. However, the displaceable part 72 then rotates with the distance reduced and comes into contact with the inner wall of the respective module housing 14 opposite this part. Any further rotation of the component 72 in the same direction then leads to a clamping-acting connecting force F and in particular to a clamping of the respective wall region of the module housing 14, which is arranged between the fixed section 70 and the displaceable component 72. Thereby, the module housings 14 are pressed towards each other and held at each other in order to prevent relative movement.

The advantages set forth above with regard to saving installation space and maximum energy density and preferred deformation behavior in the event of a crash can also be achieved with this variant.

A further general advantage of the invention and in particular of all the exemplary embodiments described is, moreover, the less complex assembly of the connecting element 16, but also the unloading. It is also possible to limit the production costs, since, for example, the module itself has to be modified only slightly, for example by being brought into the recess 24. In particular, the deformable connecting element 16 can furthermore be produced relatively easily.

List of reference numerals

1 Motor vehicle

2 front axle

3 rear axle

4 vehicle wheel

5 vehicle body structure

6 frame-like region

7 Carrier/structural Member

10 energy store

11 fixing element

12 module

13 Battery monomer

14 Module housing

16 connecting element

17 accommodating wells

24 spaces

26 hollow space at upper part

28 lower hollow space

30 clamping section

32 connecting section

34 joining structure

50 concave part

52 projection

60 saw-toothed structure

70 fixed section

71 base body

72 displaceable member

74 bolt

100 coupling area

102 contact section

104 intermediate wall

106 penetration part

108 conductor segment

110 base body

112 sealing element

114 edge region

R axis of rotation

L longitudinal axis of vehicle

F connecting force

X contact section-longitudinal axis

Claims

1. Electrical energy store (10) for a motor vehicle (1), comprising:

-a plurality of modules (12) arranged side by side, each comprising a module housing (14) and at least one battery cell (13) accommodated therein, and each being connectable with a structural member (7) of the motor vehicle (1); and

-at least one connecting element (16) which releasably connects two adjacent ones of the modules (12) to each other;

wherein the connecting element (16) is elastically deformable and is provided for generating, as a result of the elastic deformation, a connecting force (F) pressing the connected modules (12) towards one another;

characterized in that the connecting elements (16) are also provided for electrically conductively connecting the modules (12) to one another.

2. The electrical energy storage (10) according to claim 1, characterized in that the connecting element (16) comprises at least two electrical contact sections (102) which can be brought into electrically conductive contact with one of the modules (16) each.

3. The electrical energy storage (10) according to claim 2, characterized in that the connecting element (16) comprises two clamping sections (30), wherein one of the contact sections (102) is arranged at each clamping section (30).

4. The electrical energy storage (10) according to claim 3, characterized in that the orientation of at least one of the clamping sections (30) can be changed in the event of an elastic deformation of the connecting element (16).

5. The electrical energy storage (10) according to any one of claims 2 to 4, characterized in that the contact section (102) is electrically insulated with respect to the module housing (14),

and/or the contact sections (102) are connected to one another by electrically conductive conductor sections (108), wherein the conductor sections (108) are accommodated in the connecting element (16) in an electrically insulated manner from the surroundings in at least sections.

6. The electrical energy storage (10) according to any one of claims 2 to 5, characterized in that the contact section (102) is releasably received in the connecting element (16),

in particular, the contact section (102) is formed on a threaded fastener that can be inserted into the connecting element (16).

7. The electrical energy storage (10) according to any one of claims 2 to 6, characterized in that the connecting element (16) has an edge region (114) which projects laterally beyond the contact section (102).

8. Motor vehicle (1) comprising an electrical energy storage (10) according to any one of the preceding claims,

wherein the modules (12) are arranged in parallel side by side in a receiving well (17) of a body structure (5) of the vehicle (1) and the module housings (14) are separately fastened to each other at both ends in a releasable manner at the body structure (4) and are releasably connected to each other by means of the at least one connecting element (16) in the region between the housing ends of the module housings.

9. Connecting element (16) for electrically conductively connecting modules (12) of an electrical energy store (10),

wherein the connecting element (16) is elastically deformable and comprises two clamping sections (30), the orientation of which relative to each other can be changed within the range of the elastic deformation,

and wherein the connecting element (16) comprises at least two electrically conductive contact sections (102) which can be brought into contact with one of the modules (16) to be connected in each case, with the electrical connection between the modules (16) being established.

10. Method for producing an electrical energy store (10) for a motor vehicle (1),

wherein the electrical energy store (10) comprises a plurality of modules (12) arranged next to one another, each comprising a module housing (14) and at least one battery cell (13) accommodated therein, and each being connectable to a structural component (7) of the motor vehicle (1);

and wherein the method comprises:

-connecting two adjacent ones of the modules (12) with at least one connecting element (16) in a releasable and electrically conductive manner;

wherein the connecting elements (16) are electrically conductive and elastically deformable and are provided for generating, as a result of the elastic deformation, a connecting force (F) pressing the connected modules (12) towards one another.