Busbar connection with coupling sections for the physical coupling of several identical busbar connection rails

Abstract

Busbar (10; 110) for the electrically conductive connection of battery cells (142), comprising a plurality of exposed contact tongues (18; 118), each of which is designed for a metallurgical connection with a contact formation (143, 145) of a battery cell (142), wherein the contact tongues (18; 118) are integrally formed with an electrically conductive web structure (12; 112), wherein the web structure (12; 112) electrically connects the contact tongues (18; 118), wherein a cladding structure (14; 114) made of electrically insulating material is arranged on at least one section of the web structure (12; 112), wherein the busbar (10; 110) has a first coupling area (24; 124) with at least one first coupling formation (26; 126) and a length along a virtual distance axis (A) the second coupling area (30; ) arranged at a distance from the first coupling area (24; 124).130) with at least one second coupling formation (32; 132), wherein the first coupling formation (26; 126) and the second coupling formation (32; 132) are designed to be complementary such that the second coupling formation (32; 132) of the busbar (10; 110) can be coupled to a first negative feedback formation of a first connecting object (10; 110) that is different from the busbar (10; 110), wherein the first negative feedback formation corresponds in its shape and dimensions to the first coupling formation (26; 126), and that the first coupling formation (26; 126) of the busbar (10; 110) can be coupled to a second negative feedback formation of a second connecting object (10; 110) that is different from the busbar (10; 110), wherein the second feedback formation in its shape and dimensions of the second coupling formation (32;132) corresponds, wherein the electrically conductive bridge structure (112) between two contact tongues (118) has at least one fuse section (148) formed integrally with the bridge structure (112), wherein the bridge structure (112) has a smaller conductor cross-section in the fuse section than in the areas between the fuse section (148) and each of the two contact tongues (118), wherein at least a part of the fuse section (148) is exposed without being covered by the cladding structure (114).

Description

[0001] The present invention relates to a busbar for the electrically conductive connection of battery cells, in particular for use in a motor vehicle. The busbar comprises a plurality of exposed contact tongues, each of which is designed for a materially bonded connection to a contact formation of a battery cell. The contact tongues are formed integrally with an electrically conductive web structure. The web structure electrically connects the contact tongues, and a covering structure made of electrically insulating material is arranged on at least one section of the web structure.

[0002] Such a busbar connection bar is known from US 2016 / 0315304 A1. It generally serves, like the connection bar of the present invention, to form a vehicle battery as a drive energy storage device for a motor vehicle that can also be driven electrically or only electrically by establishing an electrical connection between individual battery cells.

[0003] The common busbar connects individual battery cells electrically in parallel, so that one busbar forms a battery cell pack composed of parallel-connected battery cells. Two common busbars electrically connect the battery cell packs they form in series. This creates a vehicle battery with the desired terminal voltage and charging capacity.

[0004] The known busbar connection rail has a fuse section which is designed as a melt fuse section with a significantly smaller cross-section, i.e. electrical conductor cross-section, than the conductor sections of the busbar connection rail adjoining on both sides of the melt fuse section. Since a vehicle battery has a large number of battery cells, each of which is electrically connected by means of a known busbar connection rail with the interposition of a melt fuse section to further battery cells, and since furthermore the melt fuse section is sensitive to mechanical loads due to its smaller or small material cross-section, the melt fuse section on the known busbar connection rail is injection-molded into a thermoplastic material for its stabilization and protection.The cladding structure thus formed completely surrounds the fuse section in order to protect it as best as possible from external influences and thus from unwanted premature and improper destruction.

[0005] Another busbar connection rail is known from US 9876212 B2.

[0006] To form the vehicle battery, the known busbars are cast into a battery carrier referred to as a “battery tray” in the aforementioned publications.

[0007] From US 2018 / 0375082 A1, a wiring module for attachment to a group of electricity storage elements in which a plurality of electricity storage elements with electrodes are lined up is also known.

[0008] The wiring module includes a plurality of bus bars for connecting to the electrodes and a plurality of accommodation sections in which the bus bars are respectively housed. Each of the accommodation sections has a accommodation wall arranged around the bus bar, and the accommodation wall includes a first adjacent wall and a second adjacent wall opposite the first adjacent wall. The first terminal wall of one accommodation section and the second terminal wall of the other accommodation section are arranged side by side. The first adjacent wall has a first locking portion that locks the bus bar, and an auxiliary wall that projects toward the second adjacent wall and covers the first locking portion from the second adjacent wall side. The second terminal wall has an opening in which the auxiliary wall is housed.

[0009] Further collective connecting slides are also known from US 2019 / 0206593 A1 and US 2014 / 0287622 A1.

[0010] The object of the present invention is to provide a technical teaching which makes it possible to connect battery cells to a vehicle battery as flexibly and at the same time safely as possible and thus to configure vehicle batteries of different sizes and / or charging capacities and / or terminal voltages.

[0011] The present invention achieves this object with a bus-connection rail of the type mentioned at the outset, wherein the bus-connection rail has a first coupling region with at least one first coupling formation and a second coupling region arranged along a virtual spacing axis at a distance from the first coupling region with at least one second coupling formation, wherein the first coupling formation and the second coupling formation are designed to be complementary in such a way that the second coupling formation of the bus-connection rail can be coupled to a first counter-coupling formation of a first connection object different from the bus-connection rail, wherein the first counter-coupling formation corresponds in its shape and dimensions to the first coupling formation,and that the first coupling formation of the busbar is coupleable to a second counter-coupling formation of a second connection object different from the respective busbar, wherein the second counter-coupling formation corresponds in its shape and dimensions to the second coupling formation, wherein the electrically conductive web structure between two contact tongues has at least one securing section formed integrally with the web structure, wherein the web structure has a smaller conductor cross-section in the securing section than in the regions between the securing section and each of the two contact tongues, wherein at least a part of the securing section is exposed uncovered by the cladding structure.

[0012] For the sake of simplicity, the busbar connecting rail of the present invention is hereinafter referred to simply as “connecting rail”.

[0013] Due to the complementary design of the first coupling formation and the second coupling formation, a first coupling formation of a first connecting rail can be physically coupled to a second coupling formation formed on a second connecting rail. The coupling is preferably a form-fitting coupling. Likewise, the coupling is preferably detachable as intended, i.e., without destroying the connecting rail, in order to be able to correct the spatial dimensions of an arrangement of battery cells relative to one another. This does not preclude the coupling from being made non-detachable after its manufacture and after any correction of the relative position of coupled connecting rails during a subsequent assembly process by joining processes, for example by gluing or potting. However, the coupling should preferably initially be detachable immediately after its manufacture.

[0014] The aforementioned connection object can therefore be another similar connecting rail or, if necessary, a separately designed end-side bus-connecting end rail if no further bus-connecting rail beyond the already connected connecting rail is to be connected to it. Thus, a desired plurality of similar bus-connecting rails can be coupled to one another in a continuous direction. The connecting structure thus formed, preferably from bus-connecting rails designed as identical parts, can be terminated at its respective end regions in the continuous direction by an end-side bus-connecting end rail.

[0015] The coupling regions or coupling formations preferably allow a physical connection between adjacent connecting rails independent of their electrical connection. While it should not be ruled out that a coupling of the first and second coupling formations also forms an electrical connection between the busbar connecting rails coupled by the coupling formations, this is not preferred. The electrical connections of a busbar connecting rail to a battery cell are preferably formed by a material bond, for example, by soldering or welding, in particular laser welding.Therefore, the electrical connections of a busbar are generally no longer detachable, whereas a coupling of the complementarily designed first and second coupling formations with one another should preferably be detachable at least during a period of an assembly process for forming the connecting structure in order to be able to correct a spatial arrangement of coupled busbars at least within limits.

[0016] Due to the described ability to connect similarly designed busbars to one another by means of complementary coupling areas, the busbar can be used as a modular busbar, so that a vehicle battery can be constructed in a modular manner using numerous similar busbars.

[0017] The bus-connecting rail is preferably a flat component, i.e. it extends in two mutually orthogonal spatial directions with considerably larger dimensions than in a thickness direction orthogonal to the two aforementioned spatial directions. This flat design can be curved, even multiply curved, so that the thickness direction can have locally different orientations in space. The positive coupling of a first and a second coupling formation is preferably effective along directions of relative movement which lie in the surface extension of the bus-connecting rails involved. This means that the positive coupling of the first and the second coupling formation enables a relative movement of the bus-connecting rails or connecting objects coupled thereby in directions of movement along the surface extension of the bus-connecting rails orConnecting objects are at least spatially restricted and / or completely inhibited. The extent of restriction up to complete inhibition can vary within the surface area depending on the direction. Likewise, the positive coupling can be established and released by a relative movement of the busbar connecting rails involved, preferably in a direction transverse, in particular orthogonal, to their surface area.

[0018] For example, the busbar can be imagined as being surrounded by a virtual enveloping cuboid, wherein the height dimension of the enveloping cuboid depends, on the one hand, on the curvature of sections of the busbar and, on the other hand, is significantly smaller than the dimensions in directions orthogonal to each other and to the height dimension, which are preferably the length and width directions of the enveloping cuboid. Preferably, the larger dimension of the length dimension and width dimension is at least five times, preferably at least 10 times, larger than the height dimension of the enveloping cuboid.

[0019] To ensure the simplest possible production of a positive coupling between the first and second coupling formations, one formation comprising the first and second coupling formations can have a projection, and the other formation comprising the first and second coupling formations can have a recess. To enable the above-mentioned production of a positive coupling by relative movement of the bus-connecting rail with a connection object transversely or orthogonally to the surface extension, the projection protrudes from the remaining bus-connecting rail, preferably transversely, particularly preferably orthogonally, to the surface extension, and an opening surface of the recess, which is penetrated by the projection when the coupling is established, preferably runs longitudinally, particularly preferably parallel, to the surface extension.

[0020] In case of doubt, the surface extension is an extension parallel to a plane spanned by the longitudinal direction and the width direction of the enclosing cuboid.

[0021] It is also possible to design the busbar as a base element of a vehicle battery, in particular a modular one, such that it is invariant with respect to a rotation of 180° about a rotation axis orthogonal to the surface extension. In particular, for such a case, it can be provided that each coupling formation comprising the first and second coupling formations has at least one projection and at least one recess. Preferably, each coupling formation comprising the first and second coupling formations in this case has the same number of projections as recesses.

[0022] Preferably, the busbar connection rail discussed here can not only be positively coupled to a connection object, such as another similar busbar connection rail or a busbar connection end rail outlined above, but the busbar connection rail and the connection object can also be moved relative to one another in the positively coupled state, at least in the common surface area of ​​the busbar connection rail and the connection object, within the scope of a movement play provided by the coupling. The movement space is considerably smaller than the spatial extent of the busbar connection rail and preferably also of the connection object in the surface area. This allows manufacturing tolerances on the busbar connection rail to be corrected, which manifest themselves in the form of dimensions that vary from component to component.Irrespective of the varying dimensions of several busbars used to form a vehicle battery due to manufacturing tolerances, it can be ensured that the vehicle battery formed by coupling a plurality of busbars fits into the battery housing provided for it. For this purpose, it is advantageous if the recess has a clear width which is larger than the projection in at least one direction, acting as a tolerance compensation direction. Thus, due to the larger dimension of the clear width of the recess compared to the projection penetrating it in the form-fitting coupled state, there is play in the tolerance compensation direction between the projection and the recess, and thus between the first coupling formation and the second coupling formation.

[0023] Since the direction of progression along which several busbars are physically coupled to one another generally runs parallel to the virtual distance axis between the first and second coupling regions, it is preferable for the tolerance compensation direction to run along the virtual distance axis. Varying dimensions of coupled busbars add up along the direction of progression, so that the greatest need for corrective relative movements between a busbar and a connecting object coupled to it exists in the direction in which a particularly large number of busbars or connecting objects are positively coupled to one another in a successive manner.

[0024] Additionally or alternatively, the tolerance compensation direction can run orthogonal to the virtual distance axis to enable a position correction of the busbar relative to the connecting object coupled to it in another direction that is linearly independent of the virtual distance axis. A linear combination of relative mobility in the direction of the virtual distance axis and orthogonal to it is also possible. Preferably, the play along the virtual distance axis is greater than orthogonal to it.

[0025] To further compensate for dimensional differences resulting from manufacturing tolerances, the electrically conductive web structure can have at least one spring section that can be deformed in a predetermined manner with less force than sections of the electrically conductive web structure adjoining the spring section on both sides of the spring section. For example, the electrically conductive web structure in the spring section can be designed as a meander structure with adjacent meander branches that are movable relative to one another, while the electrically conductive web structure beyond the spring section can be designed as a solid conductor strip with at least the same width as the spring section. The web structure preferably has a local longitudinal direction along which the spring section is arranged between two conventional, in particular solid, sections of the web structure.The width direction then runs orthogonally to the local longitudinal direction and orthogonally to the local thickness direction of the web structure. Instead of forming a meandering structure, the spring section can be structurally weakened relative to the adjacent conventional sections in another form, for example, by forming a comb-like structure or by locally slitting the web structure in the spring section.

[0026] In order for the spring section to be able to develop its effect in the best possible way, it is preferably not embedded in the cladding structure, but rather left out of it.

[0027] The electrically insulating material of the cladding structure can be any electrically non-conductive material. In case of doubt, materials with a resistance of at least 10 8 Ohm, preferably at least 10 9Ohm, reliably electrically insulating materials. The material is preferably designed to be molded into the shape of the cladding structure. Further preferably, the cladding structure can be produced by casting or injection molding the electrically insulating material, in particular by overmolding or / and encapsulating the web structure with the material of the cladding structure. The electrically insulating material is preferably a thermally curing plastic, in particular a thermoplastic.

[0028] The web structure is preferably made of metal, for weight reasons of aluminum or an aluminum alloy. The web structure can be a component obtained from a metal sheet, for example, by cutting or punching.

[0029] The electrical connection of the busbar to a plurality of battery cells, which are usually arranged in a common plane, can be advantageously facilitated by arranging a plurality of the contact tongues in a common arrangement plane. Preferably, the contact tongues can be elastically deflected orthogonally to the common arrangement plane using manual force in order to ensure secure contact of the contact tongues with the respective battery cells under elastic prestress before the contact tongues are firmly connected to the battery cells. The arrangement plane preferably runs parallel to the plane of the surface extension, i.e., in the case of an enveloping cuboid of the busbar, parallel to the plane spanned by the longitudinal and width directions of the cuboid.Additionally or alternatively, the contact tongues can be plastically deflected orthogonally to the common arrangement plane, in particular with manual force, in order to be able to provide the secure contact of the contact tongues on the respective battery cells under elastic prestress before the contact tongues are firmly connected to the battery cells.

[0030] In the present application, the term “plane” does not refer to an infinitely thin mathematical plane, but rather to a finitely thick technical plane.

[0031] Preferably, the tolerance compensation direction is oriented parallel to the arrangement plane, since the arrangement plane extends beyond the individual busbar to further coupled busbars and the greatest spatial correction requirement for the arrangement of the battery cells and the busbars connecting them is likely to exist in this plane.

[0032] In principle, it can be envisaged that at least one first coupling formation from the at least one first coupling formation is arranged or formed on a conductor section leading directly to a contact tongue, for example on a section of the cladding structure arranged on this conductor section, in particular molded onto it or molded around this conductor section in the circumferential direction. However, to ensure that the positive coupling of the first coupling formation with a counter-coupling formation of a connection object corresponding to the second coupling formation does not disrupt the electrical connection of a contact tongue located close to the first coupling formation to a battery cell, the at least one first coupling formation is preferably formed on a first connecting tab running along the arrangement plane.This first connecting tab preferably does not comprise any electrically conductive material, in particular any material of the web structure, at least not in the region of the formation of the coupling formation. The same preferably applies to at least one second coupling formation of the at least one second coupling formation. Accordingly, the at least one second coupling formation is preferably formed on a second connecting tab running along the arrangement plane. The second connecting tab also preferably does not comprise any electrically conductive material, in particular any material of the web structure, at least in the region of the formation of the coupling formation, and is thus preferably designed exclusively for producing the mechanical coupling with a first counter-coupling formation corresponding to the first coupling formation.

[0033] To ensure that the first and second connecting tabs can be positively coupled to one another by means of their coupling formations, without changing the relative position of one of the participating busbars orthogonally to the arrangement plane of the battery cells, the first connecting tab and the second connecting tab are preferably offset relative to one another transversely to the arrangement plane. The offset of the first and second connecting tabs transversely to the arrangement plane preferably corresponds to the thickness of one of the two connecting tabs. Both connecting tabs are preferably of the same thickness.

[0034] The first and / or the second connecting tab is / are preferably formed exclusively by injection molding, as explained above.

[0035] In principle, it should not be ruled out that at least one coupling formation from the first coupling formation and / or the second coupling formation is formed by electrically conductive material of a conductor section of the web structure configured for electrical conduction. An advantageously unrestricted possibility for the physical design of a coupling formation can be achieved by forming at least one of the at least one first coupling formation and / or at least one of the at least one second coupling formation on the cladding structure. The cladding structure is preferably formed by primary molding, particularly preferably by injection molding.

[0036] The cladding structure can be adhesively bonded to the electrically conductive web structure as a preformed component. As already explained above, the cladding structure is preferably injection-molded onto the electrically conductive web structure, i.e. it covers only part of the web structure in the injection-molded area, while another part is either bare or covered by a structure other than the injection-molded cladding structure. Alternatively or additionally, the electrically conductive web structure can be encapsulated by the cladding structure, such that the cladding structure completely surrounds the web structure in the circumferential direction in an encapsulated section. The cladding structure can also be injection-molded onto the web structure in one area, leaving sections of the web structure out, and can completely surround the web structure in another area.

[0037] If one or more battery cells connected to a bridge structure have a defect, an undesirably high current flow between the battery cells may occur through the bridge structure. In order to be able to prevent such an undesirably high current flow in a timely manner, the electrically conductive bridge structure between two contact tabs has at least one fuse section formed integrally with the bridge structure.

[0038] The bridge structure has a smaller cross-sectional area in the fuse section than in the areas between the fuse section and each of the two contact tabs electrically connected with the participation of the fuse section, so that the fuse section can serve as a melt fuse section due to its locally higher resistance.

[0039] At least part of the fuse section is exposed and uncovered by the cladding structure. This has several technical advantages: firstly, the fuse section can be visually inspected, so that any failure of battery cells can be easily detected locally. Secondly, a change in the fuse properties due to overmolding of the fuse section, as is the case in the prior art, is prevented. The thermoplastic material of the prior art that completely surrounds the fuse section also thermally insulates the fuse section, so that depending on the particular overmolding formed, fuse sections can trigger differently despite identical electrical conditions. Thirdly, an exposed fuse section can be used to fix the web structure in an injection mold for overmolding with or overmolding with thermoplastic material.This allows the web structure to be held particularly securely in the injection molding tool cavity, even when the thermoplastic is injected into the cavity at high speed. As a result, a large number of similar busbars with consistent quality and properties can be produced.

[0040] As already explained above, the spring section is also exposed and uncovered by the cladding structure in order to be able to carry out the desired elastic deformation due to external forces.

[0041] The reduction in the cross-section of the conductor section of the web structure in the securing section to form the securing section can be structurally realized by forming the securing section in a conductor section of the web structure connecting the two contact tongues along a connecting track by a constriction tapering the conductor section orthogonally to the connecting track and / or by a through-opening penetrating the conductor section. The tapered constriction can be fixed by corresponding projections in the cavity of the injection molding tool, which engage in the constriction, preferably engaging complementarily according to the key-lock principle. Preferably, projections engage in the constriction from opposite sides, so that the securing section with the cross-sectional area reduced compared to the remaining conductor section is arranged between the projections in the injection molding tool.

[0042] Likewise, a projection or mandrel in the cavity of the injection mold can penetrate the through-opening formed in the securing section of the conductor section, thereby securing the web structure in the injection mold. For effective securing, the through-opening is preferably designed to be non-rotationally symmetrical with respect to an axis passing through it. For this purpose, for example, an edge surrounding the through-opening can be designed as a polygon with straight edge sections and / or curved edge sections, the center of curvature of which is located at a distance from an axis imaginary centrally passing through the through-opening, orthogonal to its opening surface.

[0043] In the event of a collision involving a vehicle carrying and using a vehicle battery with at least one busbar formed as described above, collision-related short circuits between battery cells within the vehicle battery should be avoided. Battery cells are often arranged in a structural template corresponding to their desired spatial arrangement. This prevents, within certain limits, any displacement of the battery cells parallel to the surface area of ​​the busbars or to the arrangement plane mentioned above. However, the battery cells generally have both of their contactable contact formations or poles at one of their two longitudinal ends or one each at another of their two longitudinal ends. Undesired short circuits must therefore be caused by deformations orthogonal to the surface area of ​​the busbars or to the arrangement plane mentioned above.to the above-mentioned arrangement level is of particular importance, since such a deformation can undesirably contact a plurality of longitudinal ends of battery cells in an unpredictable manner and, for example, short-circuit them.

[0044] In order to prevent such undesired collision-induced contact, according to an advantageous development of the present invention, at least one spacing-securing section can be formed on the cladding structure of the bus-connecting rail, which has a greater height dimension orthogonal to the arrangement plane than sections of the cladding structure adjoining the at least one spacing-securing section. Due to the greater height dimension, the spacing-securing section can form a physical barrier against structures, for example sections of a battery housing, approaching the battery terminals. Preferably, the dimension of the spacing-securing section referred to as the height dimension in the direction orthogonal to the surface extension of the bus-connecting rail or to the above-mentioned arrangement plane is greater than its height parallel to the surface extension orThickness measured in the arrangement plane, which gives it a particularly advantageous area moment of inertia against bending deformation about a bending axis running parallel to the surface extension or arrangement plane.

[0045] The aforementioned distance-protection section is a particularly advantageous design of the busbar, which, to increase collision protection of the busbar, can be implemented directly as a further development of the busbar mentioned above, without the busbar having the coupling areas mentioned. The applicant also reserves the right to claim independent protection for such a busbar. A majority of the contact tongues are then located in a common arrangement plane, with respect to which the height dimension of the distance-protection section is orthogonal.

[0046] Further developments of the previously described busbar connection rail, which are not directly related to the contact areas, are also further developments of the busbar connection rail mentioned at the beginning and formed with the said distance securing section.

[0047] Preferably, the distance securing section is a solid section which can not only be easily manufactured by injection molding, but can also have a high component rigidity orthogonal to the surface extension or arrangement plane, so that it can only be deformed in the direction orthogonal to the surface extension or arrangement plane by very high forces.

[0048] Preferably, the at least one spacing section is the region with the greatest height dimension measured orthogonally to the surface extension or to the arrangement plane of the collecting connection rail. In this case, due to its physical dimensions, the spacing section determines a minimum distance of any object approaching the battery cells orthogonally to the surface extension or to the arrangement plane.

[0049] Since the contact formation of a battery cell is to be protected from unwanted contacting by a spacing section of the collecting connection rail, it is preferred that the at least one spacing section at least partially surrounds a contact tongue of the collecting connection rail that is electrically connected to the contact formation of a battery cell in the operating state of a vehicle battery.

[0050] Preferably, the contact tongue is designed as a longitudinal end of a conductor section of the web structure, so that the contact tongue is designed as a projecting longitudinal end of a conductor section referred to below as “contact conductor section” and is thus accessible for establishing a material connection with a battery pole.

[0051] Preferably, the spacing section only partially surrounds the contact tongue, so that the spacing section does not impede further contacting of the battery cell already contacted by the contact tongue by another busbar. Often, both opposite electrical poles or contact formations of a battery cell are formed at the same longitudinal end of the battery cell, so that the same longitudinal end of the battery cell is only contacted at different points by contact tongues of different busbars. Typically, two different busbars, which contact different contact formations of a battery cell with their respective contact tongues, are also physically connected to one another in a form-fitting manner by the first and second coupling formations.

[0052] To minimize the disruption of contacting one and the same battery cell with another contact tongue of another busbar, the spacing securing section is preferably interrupted in an area that extends along the direction of the conductor section and / or in an area that extends beyond the contact tongue along the virtual spacing axis. If necessary, this interruption allows the contact tongue of the other busbar to extend toward the battery cell to be contacted.

[0053] The busbar connection rail can have a plurality of contact conductor sections running side by side, wherein a contact tongue is formed on at least one longitudinal end of a contact conductor section.

[0054] Preferably, the contact conductor sections run not only next to one another, but also parallel to one another, which considerably facilitates the arrangement of the battery cells to be contacted. Preferably, the contact conductor sections run, in particular in a straight line, parallel to the virtual spacing axis. Further preferably, a contact conductor section can have a contact tongue not only at one of its longitudinal ends, but preferably at each of its opposite longitudinal ends.

[0055] Contact conductor sections running directly adjacent to one another can be electrically connected to one another by a connecting conductor section running between the contact conductor sections. To save material, the connecting conductor section can be designed with a smaller conductor cross-section than the contact conductor sections it connects.

[0056] Preferably, the spring section is formed in a contact conductor section.

[0057] The arrangement of battery cells in a particularly dense pack can be further supported by arranging the contact conductor sections offset from one another along their direction of travel.

[0058] The present invention will be explained in more detail below with reference to the accompanying drawings. It shows: Fig. 1 is a perspective view of a first embodiment of a busbar connection bar according to the present application, Fig. 2 a perspective view of a plurality of interconnected busbars of the first embodiment of Fig. 1, Fig. 3 is an exploded perspective view of the bus bar of the first embodiment of Fig. 1, Fig. 4 is a perspective view of a second embodiment of a busbar connection bar according to the present application, Fig. 5 a perspective view of the second embodiment of the bus bar of the present application with battery cells connected thereto, and Fig. 6 is an exploded perspective view of the bus bar of the second embodiment of the Fig. 4 and Fig. 5,

[0059] In Fig. 1 is a first embodiment of a modular busbar generally designated 10. The busbar 10 is in Fig. 3 shown in perspective exploded view.

[0060] The modular busbar 10 comprises an electrically conductive aluminum web structure 12, which is partially surrounded by a thermoplastic cladding structure 14. The cladding structure 14 is injection-molded onto the web structure 12.

[0061] The web structure 12 and thus the busbar connecting bar 10 have contact conductor sections 16, at whose longitudinal ends exposed contact tongues 18 are formed, i.e., recessed from the cladding structure 14, which are designed for contacting electrical poles of battery cells. Unslotted contact tongues 18 are designed for connection to one type of pole, positive or negative, of a battery cell, and slotted contact tongues 18 are designed for connection to the other type of pole, negative or positive, of a battery cell.

[0062] The contact conductor sections 16 run not only next to one another, but essentially parallel to one another and are electrically connected to one another by connecting line sections 20.

[0063] In Fig. 1 shows a virtual cuboid 22 enveloping the busbar connecting rail 10, which indicates that the busbar connecting rail 10 is a flat component whose dimension in the longitudinal direction L is greater than in the width direction B orthogonal to the longitudinal direction L and is considerably greater than in the thickness direction D orthogonal to both the longitudinal direction L and the width direction B. A main extension plane of the busbar connecting rail 10 is thus spanned by the longitudinal direction L and by the width direction B.

[0064] The busbar connection rail 10 is designed for connection to further connection objects, wherein the further connection objects are preferably similar busbar connection rails 10. For this purpose, the busbar connection rail 10 has a first coupling region 24, in which two first coupling formations 26, each in the form of two locking projections 28, protrude from the cladding structure 14 transversely to the main extension plane, preferably orthogonally to the main extension plane.

[0065] Along a virtual spacing axis A, wherein the virtual spacing axis A runs parallel to the longitudinal direction L in the illustrated embodiment, the bus-connecting rail 10 has a second coupling region 30 in which two second coupling formations 32 are formed, each in the form of two locking recesses 34. Each locking recess 34 can be penetrated and engaged by a locking projection 28 of a first coupling region 24 of another bus-connecting rail or another connection object.

[0066] Due to the locking connection that can be established between the locking projections 28 of one bus connection rail 10 and the locking recesses 34 of another bus connection rail 10, the two bus connection rails 10 can be positively coupled to one another, so that they can also be transported or relocated while coupled to one another.

[0067] In Fig. 2 shows two parallel arrangements, each with two busbars 10 coupled to one another in the manner described. The busbars lying next to one another in the width direction B are unconnected in the illustrated embodiment.

[0068] In order to adjust the relative position of the two coupled busbars 10, the locking recesses 34 along the virtual distance axis A are designed with a larger dimension than the locking projections 28 passing through them, so that the coupled busbars 10 can be adjusted along a first tolerance compensation direction T1 parallel to the virtual distance axis A (see Fig. 2) are displaceable relative to one another by the difference in the dimensions of the locking projections 28 and the locking recesses 34 along the virtual distance axis A.

[0069] The locking recesses 34 can also have a larger dimension transversely to the virtual distance axis A, in the illustrated embodiment thus along the width direction B, than the sections of the locking projections 28 which pass through them in the coupling state, so that a larger dimension can also be achieved along a second tolerance compensation direction T2 which is orthogonal to the virtual distance axis A and parallel to the main extension plane (see Fig. 2) there is a certain amount of play between coupled busbars 10, which allows a relative adjustment of the coupled busbar 10 transverse to the virtual distance axis A.

[0070] In this way, a desired number of busbars 10 can be positively coupled to one another, whereby any dimensional differences caused by manufacturing tolerances can be compensated for by the play in the coupling between locking recesses 34 and locking projections 28. This ensures that the contact tongues 18 of several busbars 10 coupled to one another are located at locations where a battery pole to be contacted is located.

[0071] Since the battery terminals of the battery cells, at least battery terminals of the battery cells with the same name, are located in a common plane parallel to the main extension plane of the busbar, in the illustrated embodiment the contact tongues 18 assigned to the battery terminals with the same name are located in a common plane. In the present example, this means that all unslotted contact tongues 18 lie in a common plane and that all slotted contact tongues 18 lie in a common plane. Then, each of the planes is an arrangement plane, which is preferably oriented parallel to the lower surface of the cuboid 22. It is not excluded that all contact tongues 18 lie in a common plane. This common plane is the arrangement plane 36 of the contact tongues 18 and is represented by the lower surface of the cuboid 22.

[0072] The first and second contact formations 26 and 32 are preferably formed on the cladding structure 14, since this is produced by injection molding and thus allows a particularly free design of the contact formations.

[0073] In the first exemplary embodiment, the locking projections 28 protrude from a section of the cladding structure 14 surrounding a contact conductor section 16 of the web structure 12. The recesses 34 or the second coupling formations 32 are formed on tabs 38 of the cladding structure 14, which are formed exclusively from thermoplastic material of the cladding structure 14 and do not surround any electrical conductor. The tabs 38 are placed on the surface 40 of a section of the cladding structure 14 from which the locking projections 28 project, so that the electrically conductive web structures 12 of two coupled busbars 10 can lie in a common arrangement plane and, above all, so that the contact tongues 18 of the coupled busbars 10 can lie in a common arrangement plane 36.

[0074] For the sake of clarity, Fig. 2 only some components and component sections are provided with reference symbols. Fig. 2 upper arrangement of two coupled busbars 10 corresponds to the lower arrangement of two coupled busbars 10. However, it is arranged rotated by 180° with respect to an axis of rotation that is orthogonal to the arrangement plane of the contact tongues 18, ie running in the thickness direction D.

[0075] The through openings 21 and 23 in the web structure 12 (see Fig. 3) serve to secure the web structure 12 in the injection mold for overmolding or encapsulation by the cladding structure 14. Since the through-openings 21 and 23 in the web structure 12 are interspersed with holders during their inclusion in the injection mold, the cladding structure 14 also has openings 25 and 27, respectively, aligned with the through-openings 21 and 23 of the web structure 12. An additional opening 29 in the cladding structure 14 is based on a holding pin in the injection mold, which rests on the surface of a contact conductor section 16 at the end face in order to avoid deformation of the contact conductor section 16 during the encapsulation of the web structure 12 with the cladding structure 14.

[0076] The web structure 12 and the connecting structure 14 are each formed in one piece.

[0077] In Fig. 4 shows a second embodiment of a busbar connection bar according to the invention and is generally designated 110. Identical and functionally identical components or component sections as in the first embodiment are designated in the second embodiment with the same reference numerals, but increased by the number 100. The second embodiment will otherwise only be described insofar as it differs from the first embodiment, to whose description reference is otherwise made in full for the explanation of the second embodiment as well.

[0078] The second embodiment of the busbar 110 includes a significantly larger number of contact tongues 118 than the first embodiment. The contact tongues 118 are also designed with a larger contact area.

[0079] Fig. 5 shows the same embodiment of the busbar 110 with a plurality of battery cells 142, whose poles 143 and 145 are contacted by contact tabs 118. Preferably, the contact tabs 118 are integrally connected, for example, by laser welding, to the poles of the battery cells 142.

[0080] A first distinguishing feature, in addition to the number and shape of contact tongues 118, lies in the roughly C-shaped spacing securing sections 144, each of which surrounds a contact tongue 118 over more than 180°. The spacing securing sections 144 have a larger dimension in the thickness direction D than the other sections of the busbar 110. The spacing securing sections 144 thus ensure a distance from a surface of a battery housing located above the busbar 110 and thus prevent undesirable electrical effects, such as short circuits, in the event of deformation of the battery housing, for example, due to an accident involving the vehicle carrying the respective battery.

[0081] As from Fig. 5, the spacing securing sections 144 surround the battery terminal of a battery cell 142, which is contacted by the contact tongue 118, which is also partially surrounded by them. The spacing securing sections 144 are injection-molded as sections of the cladding structure 114. In Fig. 5, a positive battery terminal is designated by reference numeral 143, representing the remaining battery terminals of the same name in the further battery cells 142. A negative battery terminal concentrically surrounding the positive battery terminal 143 is designated by reference numeral 145. The battery terminals 143 and 145 form respective contact formations of the battery cells 142.

[0082] A further distinguishing feature that distinguishes the second embodiment from the first embodiment is the formation of the first coupling formation 126, also on a tab 146 that is free of electrically conductive material. In the second embodiment, the tab 138, which carries the second coupling formation 132, is also arranged offset in the thickness direction D of the busbar 110, so that the contact tongues 118 of several busbars 110 coupled to one another can lie in a common arrangement plane.

[0083] A further distinguishing feature is the securing sections 148, which immediately follow a spacing securing section in the area of ​​the contact conductor sections 116. Each securing section 148 is formed as a significant cross-sectional change of a contact conductor section 116, in this case by punching out a rectangular through-hole 150, so that in a securing section 148, only two residual webs extending in the longitudinal direction L and enclosing the through-hole 150 have an electrically conductive effect. The securing sections 148 are not surrounded by the cladding structure 114, but are exposed so that they can be visually inspected.

[0084] In addition, the through holes 150 of the securing sections 148 can serve to secure and fix the web structure 112 in the injection mold during the overmolding of the web structure 112 with the cladding structure 114, as is done in the first embodiment by the openings 21 and 23 of the web structure 12.

[0085] The web structure 112 is preferably formed from aluminum. The fuse sections 148 act as fusible fuse sections. If excessive current flows, the remaining webs surrounding the through-hole 150 of a fuse section 148 melt, thus interrupting the current flow.

[0086] In addition, the web structure 112 of the second embodiment, more precisely the contact conductor sections 116, has spring sections 152 in which the material of the web structure 112 is slotted and therefore offers less resistance to deformation against an external force than adjacent solid regions of the contact conductor sections 116. In the illustrated embodiment, the spring sections 152 are formed as meander structures 154 in the contact conductor sections 116. The spring sections 152 serve to further compensate for dimensional differences, for example, due to manufacturing tolerances that may arise.

[0087] If contact conductor sections 116 have a contact tongue 118 formed in one piece at each longitudinal end, a securing section 148 is formed in one longitudinal end region and a spring section 152 is formed in the opposite longitudinal end region.

[0088] In both embodiments, the contact conductor sections 16 and 116 run straight and parallel to the virtual distance axis A.

[0089] In the perspective exploded view of Fig. 6 shows in a particularly striking manner that the one-piece cladding structure 114 has a plurality of partial web structures 112a and 112b, each of which is one-piece but physically separate from one another, which together form the web structure 112 of the bus connecting rail 110 of the second embodiment.

[0090] The web structure 112 comprises two rows of partial web structures that are parallel to one another and to the virtual spacing axis A, which are essentially identical in design but are arranged rotated by 180° relative to one another with respect to a rotation axis running in the thickness direction D. In each row of partial web structures 112a and 112b, a partial web structure 112a is initially arranged, followed along the virtual spacing axis A by two partial web structures 112b that are identical in design but are again arranged rotated by 180° relative to one another with respect to a rotation axis running in the thickness direction D. The partial web structures 112a and 112b each electrically connect battery cells 142 in parallel with one another. The parallel-connected battery cell arrangements of the respective partial web structures 112a and 112b are connected in series with one another.Two interconnected busbars 12 or 112 electrically connect the battery cells 142 contacted by them in series.

[0091] The busbars presented here allow modular vehicle batteries of any size to be reliably configured.

Claims

[1] Busbar (10; 110) for the electrically conductive connection of battery cells (142), comprising a plurality of exposed contact tongues (18; 118), each of which is designed for a materially bonded connection with a contact formation (143, 145) of a battery cell (142), wherein the contact tongues (18; 118) are formed integrally with an electrically conductive web structure (12; 112), wherein the web structure (12; 112) electrically conductively connects the contact tongues (18; 118), wherein a cladding structure (14; 114) made of electrically insulating material is arranged on at least one section of the web structure (12; 112), wherein the busbar (10; 110) has a first coupling region (24; 124) with at least one first coupling formation (26; 126) and a longitudinal a virtual distance axis (A) arranged at a distance from the first coupling region (24; 124) second coupling region (30;130) with at least one second coupling formation (32; 132), wherein the first coupling formation (26; 126) and the second coupling formation (32; 132) are designed to be complementary in such a way that the second coupling formation (32; 132) of the bus connection rail (10; 110) can be coupled to a first counter-coupling formation of a first connection object (10; 110) different from the bus connection rail (10; 110), wherein the first counter-coupling formation corresponds in its shape and dimensions to the first coupling formation (26; 126), and that the first coupling formation (26; 126) of the bus connection rail (10; 110) can be coupled to a second counter-coupling formation of a second connection object (10; 110) different from the bus connection rail (10; 110) wherein the second negative feedback formation corresponds in shape and dimensions to the second coupling formation (32;132), wherein the electrically conductive web structure (112) between two contact tongues (118) has at least one securing section (148) formed integrally with the web structure (112), wherein the web structure (112) has a smaller conductor cross-section in the securing section than in the regions between the securing section (148) and each of the two contact tongues (118), wherein at least a part of the securing section (148) is exposed uncovered by the cladding structure (114); [2] Busbar (10; 110) according to claim 1, characterized bythat one formation of first and second coupling formation (26, 32; 126, 132) has a projection (28; 128) and that the respective other formation of first and second coupling formation (26, 32; 126, 132) has a recess (34; 134), wherein the recess (34; 134) has a clear width which has a larger dimension than the projection (18; 118) in at least one direction as a tolerance compensation direction (T1, T2). [3] Busbar (10; 110) according to claim 2, characterized by that the tolerance compensation direction (T1, T2) runs along the virtual distance axis (A) and / or orthogonal to it. [4] Busbar (10; 110) according to claim 2 or 3, characterized by that a plurality of the contact tongues (18; 118) are located in a common arrangement plane (36), the tolerance compensation direction (T1, T2) being parallel to this arrangement plane (36). [5] Busbar (10; 110) according to claim 4, characterized by that the at least one first coupling formation (126) is formed on a first connecting tab (146) running along the arrangement plane and that the at least one second coupling formation (32; 132) is formed on a second connecting tab (38; 138) running along the arrangement plane, wherein the first connecting tab (146) and the second connecting tab (38; 138) are arranged offset relative to one another transversely to the arrangement plane. [6] Busbar (10; 110) according to one of the preceding claims, characterized by that at least one of the at least one first coupling formation (26; 126) and / or at least one of the at least one second coupling formation (32; 132) is formed on the cladding structure (14; 114). [7] Busbar (10; 110) according to one of the preceding claims, characterized bythat the securing section (148) is formed in a conductor section (116) of the web structure (112) connecting the two contact tongues (118) along a connecting track by a constriction tapering the conductor section orthogonally to the connecting track and / or by a through opening (150) passing through the conductor section (116). [8] Busbar connection bar (110) according to the preamble of claim 1 or according to one of the preceding claims, characterized by that a plurality of the contact tongues (18; 118) are located in a common arrangement plane (36), wherein at least one spacing securing section (144) is formed on the cladding structure (114) of the busbar connecting rail (110), which has a greater thickness dimension orthogonal to the arrangement plane than sections of the cladding structure (114) adjoining the spacing securing sections (144). [9] Busbar (110) according to claim 8, characterized bythat the at least one spacing securing section (144) is the region of the greatest thickness dimension of the bus connecting rail (110) to be measured orthogonally to the arrangement plane. [10] Busbar (110) according to claim 8 or 9, characterized by that the at least one spacing securing section (144) surrounds a contact tongue (118) at least in sections. [11] Busbar (110) according to claim 10, characterized by that the contact tongue (118) is designed as a longitudinal end of a conductor section (116) of the web structure (112), wherein the spacing securing section (144) only partially surrounds the contact tongue (118) and is interrupted in an area which is imaginary to be extended along the direction of travel of the conductor section (116) and / or in an area which is extended beyond the contact tongue (118) along the virtual spacing axis (A). [12] Busbar (10; 110) according to one of the preceding claims, characterized bythat the busbar connection rail (10; 110) has a plurality of contact conductor sections (16; 116) running side by side, wherein a contact tongue (18; 118) is formed on at least one longitudinal end of a contact conductor section (16; 116), wherein contact conductor sections (16; 116) running directly side by side are electrically conductively connected to one another by a connecting conductor section (20; 120) running between the contact conductor sections (16; 116). [13] Busbar (10; 110) according to claim 12, characterized by that the contact conductor sections (16; 116) each have a contact tongue (18; 118) at each of their longitudinal ends. [14] Busbar (10; 110) according to claim 12 or 13, characterized by that the contact conductor sections (16; 116) are arranged offset from one another along their direction of travel.

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