The present invention relates to a housing lower part of or for an energy storage device housing and to a series of energy storage device housings.
Energy storage device housings of the type under discussion are used, for example, in partly and fully electrified motor vehicles. The batteries or battery modules are installed in such housings. To implement the required ranges, their storage devices are often very large, which is not a problem with regard to economical series production. In this connection, one requirement in particular is placed on ensuring the required gas-tightness of the energy storage device housings and the housing lower parts.
It is therefore an object of the present invention to specify a housing lower part for an energy storage device housing and a series of energy storage device housings which permit efficient production with, at the same time, the attainment of the highest quality requirements.
This object is achieved by a housing lower part by a series according to the claimed invention.
According to embodiments of the invention, a housing lower part of an energy storage device housing or for an energy storage device housing, such as in particular a high-voltage storage device housing, comprises a trough-like element, wherein the trough-like element has lateral wall elements which extend along a longitudinal axis, and wherein sill elements are arranged on or fastened to the outer side of the wall elements, and each project beyond the wall elements along the longitudinal axis by way of a longitudinal section, wherein transverse elements are arranged in each case on the end side of the trough-like element and extend transversely with respect to the longitudinal axis, and wherein the sill elements are fastened to the end side of the transverse elements by way of the longitudinal sections. This configuration advantageously makes it possible to provide a complete housing lower part of an energy storage device housing on the basis of only a few components. The trough-like element has a bottom element, which defines a bottom plane. When the housing lower part is installed, this is oriented substantially parallel to a roadway plane. From this bottom plane, the wall elements extend away substantially perpendicularly (upward in relation to the roadway plane or bottom plane). In combination with the transverse elements respectively arranged at the end sides, the height of which is expediently matched to the height of the wall elements, the result is thus a circumferentially closed arrangement space for the arrangement of, for example, energy storage cells, energy storage modules, etc. When the housing lower part is installed, the aforementioned longitudinal axis extends, for example, along a direction of travel of the respective motor vehicle. In combination with the sill elements, the transverse elements advantageously form a circumferential frame which can advantageously be designed in such a way as to meet any crash requirements. The transverse elements are advantageously designed and formed in such a way as not only to form the frame but also to continue the trough-like element in such a way that a (closed) arrangement space is formed. In this connection, it should be emphasized that, as a result of this configuration, the number of joining points can be reduced to a minimum. In particular, the length of the joining points or sealing points can be reduced by a multiple as compared with known welded constructions. This reduces not only the outlay on production and assembly but also solves the tightness problem mentioned at the beginning, since the housing lower part produced in this way is already largely tight because of its construction. Thus, the trough-like element, comprising the laterally arranged or formed wall elements, is an in particular one-piece element. According to one embodiment, the wall elements are formed by reshaping regions of the bottom element, designed as a sheet metal part according to one embodiment. The longitudinal sections, which project beyond the trough-like element along the longitudinal axis, contribute considerably to the efficient structure of the housing lower part. The transverse elements can advantageously be fastened via the longitudinal sections. The transverse elements are in particular attached to the longitudinal sections at the end sides, which means that a large and wide attachment surface can be achieved. It is particularly advantageous that this attachment is made outside the arrangement space. This permits high degrees of freedom with regard to the joining techniques used, since no gas- tightness is required at this point.
According to a preferred embodiment, the sill elements are connected to the transverse elements in a form-fitting and/or force-fitting manner, in particular screwed and/or riveted. Preferably, fastening sections are formed on the longitudinal sections—and, analogously, on the transverse elements—for example in the form of bores or holes. According to one embodiment, a large number of fastening elements arranged in a distributed manner, such as screws, are arranged in the region of the longitudinal sections. According to one embodiment, three or four M8 screws are used to attach the transverse elements (for each longitudinal section or fastening section). Therefore, the frame formed by the transverse elements and the sill elements achieves very high strength and stiffness or stability.
According to one embodiment, the wall elements are integrally connected to the sill elements, in particular welded. Preferred welding methods are chosen, for example, from fusion welding methods. According to one embodiment, the attachment of the sill elements to the wall element is carried out by way of metal-inert gas welding (MIG welding). The weld seam may be drawn along the longitudinal axis or else formed in a stepped or point-like manner. Alternative welding methods, such as friction stir welding, are likewise conceivable. It has been shown that, as a result of the integral connection by way of welding, even the highest crash requirements can be met.
According to one embodiment, the wall elements have flange sections or form the latter, wherein the flange sections are preferably oriented parallel to the bottom plane and extend along the longitudinal axis, and wherein the sill elements are fastened to the flange sections. Advantageously, as a result the joining point between the sill elements and the trough- like element is displaced away from the arrangement space. Advantageously, the joining point is therefore located outside the arrangement space.
As already mentioned, the longitudinal sections permit the same advantage. As a result of the end-side fastening of the transverse elements by way of the longitudinal sections, the joining points are advantageously displaced away from the arrangement space. Thus, for example, form-fitting and/or force-fitting connections such as screws and/or rivets, etc., can be used, which would otherwise be a problem for reasons of gas-tightness to be achieved.
According to one embodiment, the transverse elements are integrally fastened to the trough-like element. According to a preferred embodiment, friction stir welding is used as a connecting technique. The transverse elements can be arranged on the trough-like element, for example in an overlapping or abutting manner.
According to a particularly preferred embodiment, the transverse elements are fastened to the trough-like element via a fusion welding method, in particular by way of MIG welding. This method can be implemented reliably and cost-effectively. The tightness, in particular gas-tightness at this point or along the weld seam is preferably produced subsequently via a sealing material applied to the connecting or joining point. The application is carried out, for example in the form of a bead, along the weld seam, on one or both sides.
According to a preferred embodiment, the connecting points or joining points or joining regions, where necessary, are sealed off subsequently, a sealing material being used for this purpose. According to a preferred embodiment, the sealing material is selected from one of the following materials: silane-modified polymer, 2K (two-component) polyurea and/or polyvinyl chloride. It has transpired that the aforementioned materials, in particular in conjunction with the application to preferably bare aluminum material, can provide optimum fluid-tightness, in particular gas-tightness. Particularly preferred is the use of a sealing material made of or based on silane-modified polymers or a silane-modified polymer.
According to a preferred embodiment, the transverse elements are formed in such a way that they continue or extend a geometry of the trough-like element. Expediently, the transverse elements each comprise a bottom section, a wall section and, depending on the configuration of the trough-like element, a flange section. Advantageously, this can ensure that a flat or planar joining region is provided between the transverse elements and the trough-like element. In other words, the joining region describes a plane which is perpendicular to a bottom plane of the trough-like element and perpendicular to the longitudinal axis. This simple geometry permits degrees of freedom in relation to the joining technique used and facilitates the subsequent sealing at the joining points, in particular, for example, because of the good accessibility. In addition, the entire housing lower part in the region of the arrangement space has only two, respectively continuous, joining regions or sealing regions.
According to one embodiment, a large number of transverse beams is arranged along the longitudinal axis, oriented transversely thereto. These are used, for example, for stiffening the housing lower part. According to one embodiment, the attachment is carried out by way of integral connecting techniques, in particular by way of adhesive bonding.
According to a particularly preferred embodiment, the transverse elements are cast parts. In particular these are metal cast components, in particular pressure diecast components. According to one preferred embodiment, the transverse elements comprise contact and/or attachment points for structural or chassis components of the respective motor vehicle. These can be produced integrally during the production of the cast parts and/or also introduced subsequently. According to one preferred embodiment, the sill elements are profiled elements, in particular extruded profiles. This configuration is distinguished by its simplicity. According to one embodiment, the transverse elements are also formed as extruded profiles.
Preferred materials for the sill elements and the transverse elements are aluminum materials or aluminum alloys.
According to a preferred embodiment, the trough-like element is an aluminum sheet part, in particular a folded-back aluminum sheet. In particular, A15 or A16 is used as a preferred material. The representation or implementation of the wall elements is carried out by the reshaping, in particular the folding back. According to one embodiment, the trough-like elements comprise geometric features such as beads, edges or the like for stiffening and for increasing the stability. Preferred wall thicknesses lie in a range from about 2 to 4 mm, in particular in a range from 2.5 to 3.5 mm and particularly preferably at 3 or about 3 mm.
According to one embodiment, the energy storage device housing comprises a correspondingly designed cover element, preferably made of aluminum and/or steel and/or plastic, in particular a composite material. The aforementioned arrangement space can be closed by the cover element. According to one embodiment, the cover element is connected to the housing lower part, preferably in a force-fitting and/or form-fitting manner, by way of an inserted or adhesively bonded seal, for example by way of appropriate screw connections. Alternatively, no separate cover is also provided. The cover is then, for example, integrally formed by the vehicle, for example by an appropriately designed floor assembly.
Finally, it should be mentioned that the energy storage device housing is not restricted to the arrangement of electrical energy storage device (cells). The energy storage device housing can also be used for the arrangement of other energy carriers, such as hydrogen. According to one embodiment, the energy storage device can accordingly comprise one or more hydrogen tanks or itself be designed as a hydrogen tank.
The invention is directed further to a series of energy storage device housings, wherein the series comprises a large number of energy storage device housings and wherein each energy storage device housing has a housing lower part according to embodiments of the invention, wherein the sill elements are profiled elements which, to represent energy storage device housings of different sizes, are preferably cut to length, and wherein the transverse elements have the same length. Advantageously, the sill elements are, for example, meter goods, which are shortened to the desired dimension as needed.
Preferably, the transverse elements have the same length. Correspondingly, the housing lower parts or the energy storage device housings have the same width. According to a preferred embodiment, the transverse elements are identical within the series. This applies, for example, to the corresponding front transverse elements in the direction of travel and to the rear transverse elements, viewed in the direction of travel, among one another. According to a further preferred embodiment, the front and rear transverse elements are also each designed identically, which means that the large number of variants can advantageously be reduced still further.
The fact that the transverse elements can comprise different attachment points for the integration of the energy storage device housing into the respective vehicle in a vehicle- specific manner, possibly subsequently, remains unaffected thereby. These are optionally introduced subsequently or already reserved during the production of the transverse elements.
The trough-like element, wherein this is expediently a sheet metal part here, in particular an aluminum sheet part, is advantageously cut to length in a manner corresponding to the length of the sill elements. The construction permits the implementation of energy storage device housings of different sizes with a minimum number of parts, wherein the necessary joining points or joining regions are shaped and positioned in such a way that, in particular, even the highest requirements on gas-tightness can be met and the production steps necessary for this purpose can be implemented efficiently and well.
Energy storage device housings of the type under discussion have a length in a range from 1.5-3.5 m. The transverse elements preferably have a length of 0.8-2.2 m.
The advantages and features mentioned in connection with the housing lower part apply analogously and correspondingly to the series and vice versa.
Further advantages and features can be gathered from the following description of embodiments of housing lower parts with reference to the appended figures.
10 Housing lower part
12 Sealing surface
14 Fastening points of housing upper part
20 Trough-like element
22 Bottom element
24 Wall element
26 Flange element
30 Sill element
32 Longitudinal section
34 Stiffening element
40 Transverse element
42 Bottom section
44 Wall section
46 Flange section
48 Joining region
49 Fastening section
50 Transverse beam
60 Longitudinal beam
70 (Form- and/or force-fitting) joining point
72 (Integral) joining point
L Longitudinal axis
E (Sealing) plane
B Bottom plane
A Arrangement space
Number | Date | Country | Kind |
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10 2020 120 516.3 | Aug 2020 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2021/069287 | 7/12/2021 | WO |