Flexible cell connector

Abstract

Flexible cell connector (3) for electrically connecting electrical contact points, in particular cells (2) of an energy storage device (1), to one another, comprising a band-shaped base body (5) which has a screw opening (7) at at least one end (6) for the passage of a shaft (12) of a fastening screw (11), wherein the base body (5) has a fabric band (8), and that at at least one end (6) a contact sleeve (10) is arranged which surrounds the fabric band (8) at least circumferentially and co-forms the screw opening (7), characterized in that the screw opening (7) has a reinforcing sleeve (15), and that the reinforcing sleeve (15) is held on the base body (5) by its plastic deformation.

Description

[0001] The invention relates to a flexible cell connector for electrically connecting electrical contact points, in particular cells of an energy storage device, to one another, comprising a band-shaped base body which has a screw opening at at least one end for the passage of a shaft of a fastening screw.

[0002] Furthermore, the invention relates to a device having at least two electrical units, in particular a control unit, energy storage device, energy cell and / or module for a motor vehicle, wherein each unit has at least one electrical contact point, and wherein at least two of the contact points are connected by a cell connector as described above.

[0003] Cell connectors of the type mentioned above are already known from the prior art. Energy storage devices, particularly high-performance energy storage devices, typically consist of a large number of electrical cells that must be electrically connected to one another. Particularly in automotive engineering, where the increasing electrification of drive technology is increasing the demands on energy storage devices, it is desirable to connect as many cells as possible in an energy storage device to improve capacity and the maximum achievable electrical voltage. However, due to the compact design of energy storage devices, which are designed to take up as little space as possible in the vehicle, temperature fluctuations occur during operation. If the cells were firmly or rigidly electrically connected to one another, these temperature fluctuations could lead to high stress on the connection, causing permanent damage.However, vibrations and shocks occurring while driving can also impair or damage the cell connections. At the same time, the cell connector must be able to transmit a high current between the cells, which requires a correspondingly large cable cross-section for the cell connector. To combine these objectives, it is known to provide flexible or flexibly deformable cell connectors that electrically connect one cell to another. This flexibility allows for longitudinal expansion or stretching during temperature fluctuations without building up critical mechanical stress. Furthermore, this flexibility allows vibrations and shocks between neighboring cells to be compensated or balanced out, while still providing a large cable cross-section.

[0004] For this purpose, for example, published patent application DE 10 2009 058 723 A1 proposes a cell connector that is flexibly deformable both longitudinally and transversely thereto. For this purpose, the cell connector has a base body comprising a sheet metal strip with a flexible, laminated bending section. The sheet metal strip also has a screw opening at at least one of its ends, through which a fastening screw is inserted to fasten the cell connector to a contact point of an energy cell or to a cell contact of the cell. The screw shaft is passed through the opening and screwed into a mating thread of the contact point, so that the screw head then presses the cell connector against the cell contact.

[0005] Another cell connector is known from published patent application EP 2 846 376 A1, in which the sheet metal strip is formed from several layers of metallic foil folded over one another. Another flexible cell connector, designed as a composite cell connector, is known from published patent application DE 10 2012 019 108 A1. For this purpose, a plurality of bundles of strands are arranged one above the other and radially surrounded by a tube or sheath that holds the strands together. The strands are connected at their ends with terminal plates, with the terminal plates or caps having a screw opening remote from the strands.

[0006] Further electrical and flexible connectors are known from the published patent applications DE 100 57 140 A1 and DE 10 2012 004 532 A1.

[0007] The invention is based on the object of creating an improved cell connector which offers high flexibility in a small installation space and at the same time provides a high cable cross-section.

[0008] The object underlying the invention is achieved by a cell connector with the features of claim 1. This is characterized in that the base body is designed as an electrically conductive fabric strip, and in that a contact sleeve is arranged on at least one end, which surrounds the fabric strip at least circumferentially and also forms the screw opening. The contact sleeve is in particular pushed onto the end. Because the contact sleeve also forms the screw opening, the screw opening extends through the contact sleeve on the one hand and the fabric strip or the base body itself on the other. A fastening screw is thus passed through both the contact sleeve and the fabric strip. This ensures that when the fastening screw is screwed into a mating thread of the contact point, not only the contact sleeve but also the fabric strip located in the contact sleeve is pressed.This increases the electrical contact area of ​​the individual fibers of the fabric tape in the area of ​​the contact sleeve, thus reliably ensuring particularly advantageous current transmission and a favorable cable cross-section up to the contact point. The fabric tape makes the base body particularly flexible, particularly at the end with the screw opening. By enclosing the screw opening with the contact sleeve, which further forms or helps to form the screw opening, the fabric tape is tensioned and deformed during the screwing process, thus maximizing the number of contact surfaces in the fabric tape and with the contact sleeve. The contact sleeve offers a secure mechanical hold for the cell connector to the cell contact and the advantageous electrical performance of the cell connector.

[0009] According to a preferred embodiment of the invention, the sleeve is designed as a deformable metal or copper sleeve. This ensures advantageous electrical conductivity and also ensures the compression of the fabric tape within the sleeve. The contact sleeve is preferably tinned at least in the area of ​​the screw opening to ensure advantageous electrical contact with minimal corrosion.

[0010] Furthermore, the invention provides for the screw opening to have a reinforcement sleeve. The reinforcement sleeve ensures that the screw opening does not change radially during screwing and, in particular, that the fabric tape does not enter the screw area during screwing. This also allows for higher screwing torques in the screw connection area, which could otherwise lead to damage to the fabric tape. The reinforcement sleeve is inserted into the screw opening.

[0011] According to the invention, the reinforcement sleeve is held to the base body by its plastic deformation. The reinforcement sleeve is thus attached to the base body by subsequent plastic deformation. This ensures secure holding and locking of the reinforcement sleeve and, in particular, advantageous pre-assembly of the reinforcement sleeve or the cell connector with the reinforcement sleeve.

[0012] In particular, the reinforcement sleeve is designed as a deep-drawn part, in particular in one piece with the contact sleeve, whereby a simple and cost-effective realization of the plastic deformation of the reinforcement sleeve on the base body can be achieved.

[0013] According to a preferred embodiment of the invention, the base body has an electrically insulating sheathing of the fabric tape. This prevents unwanted contact with the electrically conductive parts of the cell connector, thus simplifying assembly.

[0014] In particular, the sheathing is a plastic sheathing that can be manufactured cost-effectively. In particular, the plastic sheathing is subsequently applied, in particular sprayed, to the fabric tape.

[0015] Furthermore, it is preferably provided that the fabric tape comprises fabric fibers made of aluminum and / or copper. In the context of the present invention, a fabric tape is understood to be a construct of interwoven fabric fibers that form a rigid structure, namely the fabric tape, with flexible properties. A rigid structure is understood to be an object that maintains its shape, particularly even under load, even without further measures, in particular without the aforementioned sheathing.

[0016] The energy storage device according to the invention with the features of claim 8 is characterized by the flexible cell connector according to the invention, which, for example, electrically connects two cells of the energy storage device. In particular, at least one of the contact points to which the cell connector is connected preferably has an internal thread, in particular in the form of a threaded bushing, into which a fastening screw, which is guided through the screw opening of the cell connector, is screwed or can be screwed. This results in the advantages already mentioned.

[0017] Further advantages and preferred features and combinations of features emerge in particular from the above description and from the claims. The invention will be explained in more detail below with reference to the drawings. Fig. 1 an energy storage device for a motor vehicle in a simplified representation, Fig. 2 a cell connector of the energy storage device in a perspective view, Fig. 3 a sectional view of the cell connector according to a first embodiment not according to the invention, Fig. 4 a sectional view of the cell connector according to a second embodiment not according to the invention, Fig. 5 a sectional view of the cell connector according to a third embodiment of the invention, and Fig. 6 a sectional view of the cell connector according to a fourth embodiment of the invention.

[0018] Fig. Figure 1 shows a simplified representation of an energy storage device 1 for a motor vehicle. The energy storage device 1 is designed as a high-performance energy storage device and has a plurality of energy cells 2 arranged in a housing. The cells 2 are each electrically connected to one another. For this purpose, cell connectors 3 are provided, each of which electrically connects a contact point 4 of one cell to the contact point 4 of an adjacent cell 2. The cells can be connected to one another in parallel and / or in series using the cell connectors 3.

[0019] Fig. Figure 2 shows a perspective view of one of the cell connectors 3. This comprises a strip- or band-shaped base body 5, each of which has a screw opening 7 at its ends 6, which extends through the base body 5. The screw openings 7 are formed as elongated holes.

[0020] The base body 5 has an electrically conductive fabric band 8, as shown in a cutout in Fig. 2, which comprises a plurality of fabric fibers made of aluminum and / or copper, which are interwoven to form a band-like structure that independently maintains its shape, yet is flexibly deformable. The fabric band 8 is enclosed by a sheath 9, which is designed as a plastic sheath. In this case, the sheath 9 extends only to the ends 6 of the fabric band 8, so that the ends 6 are free of the sheath. Instead, the ends 6 are each provided with an electrically conductive contact sleeve 10, which is pushed onto the respective end 6.

[0021] Fig. 3 shows a sectional view along the line AA from Fig. 2 the cell connector 3 at the level of one of the screw openings 7. It can be seen that the screw opening 7 extends through both the contact sleeve 10 and the fabric tape 8. For fastening, a fastening screw 11 is guided with its screw shaft 12 through the screw opening 2 and screwed into an internal thread 14 of the contact point 4 until its screw head 13 rests on the upper side of the cell connector 3. If the screw 11 is now screwed into a mating thread on the cell contact 4, the contact sleeve 10 and the fabric tape 8 contained therein are clamped between the screw head 13 and the contact point. This compresses the fabric tape 8 and also deforms the contact sleeve 10 in the direction of the contact point 4. Due to the deformation, the individual fibers of the fabric tape 8 are deformed and pressed together, so that the number of contact contacts and the resulting contact area increases.The contact sleeve 10 is preferably made of copper, in particular with a tin coating in the area of ​​the screw opening 7, in order to achieve advantageous electrical contact with the fabric strip 8 on the one hand and the fastening screw 11, which is preferably also electrically conductive, on the other hand. The contact point 4 is preferably also electrically conductive on its upper side facing the cell connector 3 to ensure reliable transmission of electrical energy with high power.

[0022] Because the base body 3 has the fabric band 8 and the sheathing 9 is preferably elastically deformable, in particular as a plastic sheathing, the cell connector 3 is flexible in its longitudinal extent, so that on the one hand assembly tolerances / manufacturing tolerances and on the other hand stresses arising during operation can be resolved by the flexible deformation of the cell connector 3. In particular, temperature-related length changes can be easily compensated and shocks or vibrations can be dampened or compensated. In particular, the cell connector 3 has, as shown in Fig. 2, has a basic shape in which the base body 5 is curved in the middle, so that when loaded in the longitudinal direction, in particular when the ends 6 are moved towards each other, a preferred direction for further bulging of the base body 5 is already predetermined, so that no stresses can arise after assembly by the cell connector 3.

[0023] Fig. Figure 4 shows a further embodiment of the cell connector 3 based on the aforementioned sectional view along line AA. In contrast to the previous embodiment, a reinforcement sleeve 15 is now inserted into the screw opening 7. The reinforcement sleeve is made, for example, of plastic and / or an elastically conductive material and serves to ensure increased screwing torques when fastening the cell connector 3 to the contact point 4 using the fastening screw 11, without damaging the fabric tape 8 or the contact sleeve 10. The reinforcement sleeve 15 is cylindrical and can therefore be easily inserted into the screw opening 7. The contour of the reinforcement sleeve 15 expediently corresponds to the contour of the screw opening 7.

[0024] Fig. 5 shows a further embodiment in which a reinforcement sleeve 15 is inserted into the screw opening 7. In contrast to the previous embodiment, the reinforcement sleeve 15 is not cylindrical, but has a T-shaped longitudinal section with a bent-over collar 16 that rests on the underside of the fabric strip 8. Alternatively, the collar 16 rests on the underside of the contact sleeve 10 or is formed by the contact sleeve 10 itself. In this case, the reinforcement sleeve 15 is designed in particular as a deep-drawn part 17 that is deep-drawn into the screw opening 7 for production. In particular, the contact sleeve 10 is designed such that it has an edge section that projects inwards into the screw opening 7 and is bent against the inside of the screw opening 7 by the deep-drawing process in order to define the screw opening on its inside.The inwardly pivoted leg 18 is thus formed as part of the contact sleeve 10. Through the deep drawing, on the one hand, the contact sleeve 10 is securely held to the fabric band 8 and, on the other hand, the reinforcement sleeve 15 is easily and cost-effectively implemented in the screw opening 7.

[0025] Fig. 6 shows a further embodiment, which differs from the previous embodiment in that the reinforcement sleeve 15 has a collar 16 on both the underside and the top, so that the reinforcement sleeve 15 is securely held in the screw opening 7. In this case, too, the collar 16 can be manufactured by the contact sleeve 10. Alternatively, the reinforcement sleeve 15 is formed separately from the contact sleeve 10 and mounted on the screw opening 7, in particular by subsequent deformation of the collar 16.

[0026] While in the present exemplary embodiment, the use of the cell connector 3 is limited to connecting two cells 2 of an energy storage device 1 to one another, the advantageous cell connector 3 can of course also be used to connect other electrical units. Thus, according to a further exemplary embodiment (not shown here), the cell connector 3 is used to electrically connect two energy storage devices 1 or two energy storage modules, each having a plurality of cells 2. The cell connector 3 can also be used to contact a control unit or other electrical units or modules, in particular of a motor vehicle. List of reference symbols 1 energy storage 2 cell 3 cell connectors 4 Contact point 5 basic bodies 6 End 7 screw opening 8 fabric tape 9 Sheathing 10 contact sleeve 11 Fixing screw 12 screw shaft 13 Screw head 14 internal threads 15 Reinforcement sleeve 16 collars 17 Deep-drawn part 18 legs

Claims

[1] Flexible cell connector (3) for electrically connecting electrical contact points, in particular cells (2) of an energy storage device (1), to one another, comprising a band-shaped base body (5) which has a screw opening (7) at at least one end (6) for the passage of a shaft (12) of a fastening screw (11), wherein the base body (5) has a fabric band (8), and that at at least one end (6) a contact sleeve (10) is arranged which surrounds the fabric band (8) at least circumferentially and forms the screw opening (7), characterized by that the screw opening (7) has a reinforcing sleeve (15), and that the reinforcing sleeve (15) is held on the base body (5) by its plastic deformation. [2] Flexible cell connector according to claim 1, characterized by that the contact sleeve (10) is designed as a deformable metal or copper sleeve. [3] Flexible cell connector according to one of the preceding claims, characterized by that the reinforcing sleeve (15) is designed as a deep-drawn part (17). [4] Flexible cell connector according to claim 3, characterized by that the reinforcement sleeve and the contact sleeve are formed integrally with each other. [5] Flexible cell connector according to one of the preceding claims, characterized by that the base body (5) has an electrically insulating sheath (9) of the fabric tape (8). [6] Flexible cell connector according to one of the preceding claims, characterized by that the sheath (9) is an elastically deformable plastic sheath. [7] Flexible cell connector according to one of the preceding claims, characterized by that the fabric tape (8) has fabric fibers made of aluminum and / or copper. [8] Device with at least two electrical units, in particular control unit, energy storage, energy cell and / or module, wherein each unit has at least one electrical contact point (4), and wherein at least two of the contact points (4) are electrically connected to one another by a flexible cell connector (3), characterized by that the cell connector (3) is designed according to one of claims 1 to 7.

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