The invention relates to a battery comprising a plurality of voltage-generating cells which are in particular arranged adjacent to one another and comprising a plurality of fastening/bearing points which are spaced apart from one another and on which the battery is fastened or bears, wherein at least a first portion of said cells with a first mass, and optional further constituent parts of the battery with a further mass, come to rest between the fastening/bearing points.
Batteries are generally constructed from a plurality of voltage-generating cells in order to be able to deliver a demanded voltage, a demanded current and/or a demanded capacitance. In particular in the case of relatively high-power batteries such as are often used for electric vehicles, it is often the case that several hundred cells are connected to one another. The cells have a correspondingly high total weight and, in particular in an automobile, are subjected to occasionally intense accelerations, for example during braking or when travelling over uneven roadway surfaces. To hold the cells in position in all driving situations, holding devices which are, in part, of extremely massive design are known from the prior art. A disadvantage of said holding devices is that they considerably increase the weight of the battery and therefore of the vehicle. As is readily apparent, the driving performance of the automobile is thereby curtailed.
It is therefore an object of the invention to specify an improved battery, in particular one which has a reduced weight.
The invention is achieved by means of a battery of the type specified in the introduction in which the first portion of the cells absorbs at least a substantial part of the bending/shear load arising in the battery between the fastening/bearing points, and an I-shaped or H-shaped intermediate element is arranged at least between two voltage-generating cells.
In accordance with the invention, the mechanical structure of the cells is thus utilized to absorb a bending load arising in the battery. The cells often have a relatively massive metal casing. For example, in the case of so-called “metal can” cells, the rolled chemistry-related fittings of the cell are situated in a metal sleeve which is extremely stable and thereby protects the insides of the cell. In accordance with the invention, at least a part of the bending/shear load arising in a battery is now conducted via said cell walls. For optimum force transmission from one cell to the next and also so that the cells remain in position with respect to one another, an I-shaped or H-shaped intermediate element is arranged between said cells. A support structure for receiving the cells, if such a support structure is required at all, can thus be designed to be correspondingly more fragile. It is advantageously possible in this way for the weight of the battery and therefore of the vehicle to be reduced considerably. As a direct result of this, the driving performance of the automobile is improved.
Within the context of the invention, “cells adjacent to one another” means cells between which there is no spacing or only a small spacing. The cells may be in contact with one another, though this is not imperative. It is also conceivable for further components to be arranged between the cells, which components partially or completely fill out the intermediate space between two cells.
Advantageous embodiments and refinements of the invention will now emerge from the subclaims and from the description in conjunction with the FIGS.
It is expedient if the first portion of the cells is provided for absorbing a substantial part of the bending/shear load resulting from the acceleration acting in the vertical direction on the first mass and the optional further mass. A battery is often installed/used substantially in a horizontal position, wherein the battery is supported at at least two points. Owing to the gravitational acceleration acting on the mass of the cells and on the mass of further optional components, a bending/shear load arises in the battery between the bearing points, which bending/shear load is, in accordance with the invention, absorbed to a significant extent by the cells themselves the battery is installed in an automobile and said automobile is travelling on a roadway with an uneven roadway surface, a multiple of the gravitational acceleration may self-evidently also act on said masses, correspondingly increasing the bending/shear load.
It is furthermore expedient if the first portion of the cells is provided for absorbing a substantial part of the bending/shear load resulting from the acceleration acting in the horizontal direction on the first mass and the optional further mass. If the battery is installed/used substantially in a vertical position and the hearing/fastening points are spaced apart vertically, then a horizontal acceleration (for example when the vehicle is braking or cornering) leads to a bending/shear load, analogously to the vertical acceleration. It is self-evidently also possible for combined forces to arise, for example if the bearing/fastening points are spaced apart both horizontally and also vertically.
It is furthermore expedient if the substantial part amounts to at least 50%, preferably at least 75% and more preferably at least 90% of the total bending/shear load. In this way, it is possible for additional support elements to be of relatively fragile and therefore also weight-saving construction. The battery is thus of lighter overall weight, without any significant losses in stability. It is noted at this juncture that the load present in the battery may also be determined on the basis of an equivalent stress. Equivalent stress is an expression from the field of science of strength of materials, and refers to a fictitious single-axis stress which represents the same material loading as a real, multi-axis stress state.
It is furthermore expedient if the first portion of the cells absorbs the entire bending/shear load arising between the fastening/bearing points. In this variant of the invention, the entire load that arises is absorbed by the cells themselves. Additional support elements can therefore be dispensed with.
It is furthermore advantageous if a plate-shaped intermediate element which has elastic ribs at least on one side is arranged at least between two voltage-generating cells. Length compensation can thus take place between the cells by virtue of the ribs being deformed to a greater or lesser extent. The plate-shaped intermediate element is preferably arranged in that region of the cells which is free from the I-shaped or H-shaped intermediate element, such that the transmission of force between the cells takes place predominantly via said I-shaped or H-shaped intermediate elements. Alternatively, the pre-shaped intermediate element may also bear against the I-shaped or H-shaped intermediate element, in particular against the side flanks thereof,
It is particularly advantageous if the ribs bear against a cell, and a groove between two ribs delimits, together with the cell, a channel which is provided for conducting a gaseous or liquid heat carrier. In said variant of the invention, the ribs therefore perform a dual purpose, in that they firstly permit length compensation between the cells but secondly, together with the also form channels through which a heat carrier can flow. As a result of the said dual purpose, the number of components required for a battery can be reduced significantly.
It is expedient if at least two voltage-generating cells and at least one intermediate element are adhesively bonded to one another. In said variant of the invention, cells adhesively bonded to one another form an assembly via which bending/shear forces can be transmitted. It is advantageous for no further components to be required for the connection of the cells.
It is furthermore expedient if at least two voltage-generating cells and at least one intermediate element are screwed to one another. In this way, the cells can also be detached from one another, which offers advantages in particular during the repair or disposal of a battery.
It is furthermore expedient if at least two voltage-generating cells and at least one intermediate element are pressed against one another by means of tension straps or tension rods which generate a compressive preload. In this way, a compressive preload is generated which prevents widening of the gap between two cells in the region in which the bending torque causes a tensile stress. This means that the compressive preload generated by the clamping/tension straps is greater in this region than the tensile stress caused by the bending load. Instead of clamping/tension straps, it is also possible for tension rods, for example stud bolts, to be provided which press the cells against one another via plates. Said measures may self-evidently be used in addition to adhesive bonding.
In one advantageous variant of the invention, the battery comprises a support element which spans at least two fastening/bearing points and which serves for absorbing at least a part of the bending/shear load remaining after subtraction of the part absorbed by the cells. The cells are, under some circumstances, not suitable for absorbing the entire bending/shear load which arises. Instead of adapting the cells, which may possibly involve a large amount of expenditure and leads to non-standardized cells, an additional support element is provided which absorbs that part of the bending/shear load which can no longer be absorbed by the cells,
Finally, it is also particularly advantageous if the support element is hollow and is provided for conducting a gaseous or liquid heat carrier. In said variant of the invention, the support element thus performs a dual purpose in that it firstly absorbs bending/shear forces and secondly also contributes to the temperature control of the battery or of its cells. As a result of the said dual purpose, the number of components required for a battery can be reduced significantly.
The above embodiments and refinements of the invention may be combined with one another in any desired way.
The present invention will be explained in more detail below on the basis of the exemplary embodiments illustraten in the schematic FIGS. of the drawing, in which:
Here, the battery 1d may be assembled in a modular manner in any desired way. For example,
The cooling plates 12 and/or the cover plate 13 likewise perform a supporting function in this case. They absorb that part of the bending/shear load which remains after subtraction of the part absorbed by the cells 2. Even though the cooling plates 12 and/or the cover plate 13 perform a supporting function, a substantial part (for example 50%, 75% or 90%) is nevertheless absorbed by the cells 2.
The batteries 1a to 11 illustrated in
The first portion of the cells 2 is now designed to absorb at least a substantial part of the bending/shear load arising between the fastening/hearing points. The bending/shear load is caused for example by the acceleration acting in the vertical direction on the first mass and the optional further mass, for example, when the battery 1a to 11 is installed/used substantially in a horizontal position. The bending/shear load may however also be caused by the acceleration acting in the horizontal direction on the first mass and the optional further mass, for example, if the battery 1a to 11 is installed/used substantially in a vertical position. Mixed forms are self evidently also conceivable, for example if the battery 1a to 11 is installed obliquely, or if the bearing/fastening points are spaced apart from one another both horizontally and also vertically. It is in particular also conceivable for the structure formed by the battery 1a to 11 to be of cantilever form at least in sections.
It is pointed out at this juncture that the batteries 1a to 11 illustrated in
Finally, it is pointed out that
Although embodiments have been described herein, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
The present application is a National Stage Application of PCT International Application No. PCT/EP2010/070700 (filed on Dec. 23, 2010), under 35 U.S.C. §371, which claims priority to U.S. Provisional Patent Application No. 61/289,894 (filed on Dec. 23, 2009), U.S. Provisional Patent Application No. 61/356,239 (filed on Jun. 18, 2010), U.S. Provisional Patent Application No. 61/356,071 (filed on Jun. 18, 2010), which are each hereby incorporated by reference in their respective entireties.
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP10/70700 | 12/23/2010 | WO | 00 | 10/9/2012 |
Number | Date | Country | |
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61289894 | Dec 2009 | US | |
61356239 | Jun 2010 | US | |
61356071 | Jun 2010 | US |