Arrangement of a traction battery in a motor vehicle

Abstract

Arrangement of a traction battery (5) in a motor vehicle, which is composed of several cell assemblies (6) of battery cells, wherein the cell assemblies (6) are connected at least on one side to cooling plates (7) and are received in a battery box (1; 14) to be attached to the motor vehicle, characterized in that the cooling plates (7) through which coolant flows directly form the underbody of the battery box (1; 14), that the cooling plates (7) forming the underbody of the battery box (1; 14) are enclosed by a common frame (2), that the cooling plates (7) are inserted into the frame (2), and that the cooling plates (7) are connected to a coolant supply (9) via the frame (2) which has at least one closed hollow profile.

Description

[0001] The present invention relates to the arrangement of a traction battery in a motor vehicle according to the preamble of claim 1.

[0002] Such an arrangement is shown, for example, in DE 198 28 252 A1, in which cell assemblies of a traction battery (for example, a lithium-ion high-voltage battery) are arranged in a battery box and cooled by upright cooling plates with coolant. The coolant supply is provided via cooling channels formed by the internal and external walls of the battery box.

[0003] German patent DE 10 2008 059 964 A1 discloses a further arrangement of a traction battery in which a cooling plate forms the base of a cell assembly of battery cells, which is separately connected to a coolant supply. A special battery box is not shown here.

[0004] From DE 10 2004 005 394 A1, a generic electrochemical energy storage device is known which has heat exchanger units with several electrochemical storage cells.

[0005] DE 10 2009 029 629 A1 discloses a heat exchanger for temperature control of vehicle batteries. DE 10 2008 027 293 A1 discloses a device for cooling a vehicle battery. DE 198 49 491 C1 discloses an electrochemical energy storage device.

[0006] The object of the invention is to propose an arrangement of the generic type which is particularly suitable for the mass production of motor vehicles which may be motorized and / or designed differently and which can be produced cost-effectively in terms of manufacturing technology.

[0007] The problem is solved by the features of claim 1. Advantageous and particularly useful embodiments of the invention are described in the dependent claims.

[0008] According to the invention, it is proposed that the cooling plates, through which coolant flows, are connected to the coolant supply via a frame comprising closed hollow profiles. Such a frame with integrated coolant channels offers flexible and numerous design options for adapting the battery box to given installation conditions, battery sizes, coolant distribution, etc., and can also be easily adapted to different vehicle types.

[0009] According to the invention, the cooling plates are inserted into a common frame that encloses them, and these frames directly form the base of the battery box. This results in a simple, lightweight design that is easy to manufacture and also allows for improved cooling via the exposed sections of the cooling plates.

[0010] Furthermore, if the cooling plates, which are approximately rectangular in plan view, are aligned longitudinally and / or transversely within the common frame, the outline of the battery box can be advantageously adapted to given installation conditions; for example, the battery box can be T-shaped, double-T-shaped, etc., as viewed from above, so that other vehicle components such as wheel guidance elements or the like can be provided in between. This design also allows for the use of identical parts, for example, on the cooling plates, due to its modular construction.

[0011] In a particularly advantageous embodiment of the invention, the frame can be formed in a modular construction by several longitudinal and transverse beams that are fluid-tightly and rigidly connected to one another. In particular, the longitudinal and transverse beams can be telescopically connected to one another via plug-in connections and optionally welded. The modular design principle can be further optimized by joining the longitudinal and transverse beams using T-shaped and / or angular connecting elements, whereby the connecting elements can also be used as identical parts in high quantities.

[0012] When multiple cooling plates are arranged side by side, support struts can be provided between them. These struts are attached to the surrounding frame and provide additional support for the cooling plates or stiffen the frame structure. The support struts are preferably aligned longitudinally with the cooling plates, with the cooling plates resting longitudinally on the support struts and / or frame members at appropriately aligned overlap areas. This has the considerable advantage that the cooling plates are held in the frame without stress, even with differing coefficients of thermal expansion of the materials used and large temperature differences. Preferably, the cell assemblies of the traction battery are only bolted to the frame and, if applicable, the support struts, while the cooling plates are supported without bolts between the frame members and, if applicable, the support struts.

[0013] Furthermore, the cooling plates can form a flat support surface for the cell assemblies of the traction battery together with the support struts and, if applicable, the frame, which allows for a particularly compact design of the traction battery that requires little installation space, especially when the traction battery is arranged on a flat body underbody.

[0014] Preferably, the cooling plates can be made of extruded profiles with cooling channels, constructed from a light alloy, and the frame with its supporting struts can be made of sheet steel. This results in a cost-effective design with lightweight cooling plates and a torsionally rigid frame.

[0015] In an advantageous embodiment of the invention, an intermediate frame can be mounted on the frame, serving as a height adjustment for a cover of the traction battery or for an adjacent body component of the vehicle. The intermediate frame, made, for example, of a light metal alloy or plastic, increases the flexibility of the design and the ability to adapt the traction battery to different installation conditions, etc. The intermediate frame can optionally be attached to the frame simply by means of bolted connections, making it particularly easy to assemble.

[0016] The subframe can also support a cover for the traction battery via spacers, or a foil covering the top of the traction battery can be attached to the subframe. Alternatively, the subframe can be geometrically designed to fit snugly against the vehicle's underbody. The cover can also be held in place by spacers against the laterally closing plates of the battery cells.

[0017] In a further advantageous adaptation to the given installation conditions of motor vehicles, the frame accommodating the cell assemblies can be subdivided into several stepped levels with cooling plates, each supporting the cell assemblies of the traction battery. Considering the modular design of the traction battery frame, this represents only a marginal additional effort and allows, for example, functional or auxiliary components of the motor vehicle to be installed beneath the higher section of the traction battery.

[0018] Furthermore, one or more of the cooling plates can be inserted into the frame perpendicular to the frame's load-bearing plane, with the cell assemblies aligned accordingly. Support frames composed of hollow profiles can also be used to mount the cooling plates without stress. These frames are advantageously connected to the coolant supply via the common frame and are only bolted to the common frame and the cell assemblies of the traction battery, while the cooling plates are held in place by overlapping sections between them.

[0019] Finally, one or more mounting brackets or mounting consoles may be provided on the common frame for attaching the frame to the underbody of the vehicle's body.

[0020] Several embodiments of the invention are explained in more detail below with reference to the accompanying schematic drawing. The drawing shows: Fig. 1 a liquid-cooled traction battery in the assembled state, arranged in a battery box with a common frame, subframe and end cover; Fig. 2 the battery box with traction battery according to Fig. 1 in exploded view; Fig. 3 a top view of the underside of the battery box according to the Fig. 1 and Fig. 2, with rectangular cooling plates, the surrounding frame and several support struts; Fig. 4 the common frame of the battery box to Fig. 3 in exploded view of the longitudinal and transverse beams, which can be telescopically connected to each other via plug connections; Fig. 5 a crossbeam of the common frame according to Fig. 4 with connections for the coolant supply of the adjacent cooling plate; Fig. 6 a corner connecting element of a Fig. 4 alternative frames, which are composed of separate connecting elements and longitudinal and transverse beams; Fig. 7 a top view of a section of the underside of the battery box showing the attachment points of the cell assemblies of the traction battery to be attached to the cooling plates; Fig. 8 a cut according to line VIII - VIII of the Fig. 7 by two adjacent cooling plates and a supporting strut of the underbody; Fig. 9 a spatial view of the common frame and an intermediate frame attached via plug connections, enclosing the cell assemblies of the traction battery; Fig. 10a a simplified section according to line X - X of the Fig. 9 through the intermediate frame with attachable end cap; Fig. 10b a sectional view along line X - X of the Fig. 9 by an alternative intermediate frame with a hanging device for a cover film; Fig. 10c a sectional view along line X - X of the Fig. 9, in which, alternatively, the intermediate frame is designed to fit snugly against the underbody of a motor vehicle; Fig. 12. In a spatial representation, an alternative battery box with a stepped design of the common frame and with cooling plates positioned at different heights for the cell assemblies and partly vertically arranged cooling plates; and Fig. 13 one of the support frames according to Fig. 12 in individual presentation.

[0021] In the Fig. Reference numeral 1 denotes a complete battery box, which can be mounted on the underbody (not shown) of a motor vehicle and, viewed from the outside, comprises a lower common frame 2, an intermediate frame 3, and an upper end cover 4. For clarity, the end cover 4 is only indicated by its contour lines. Fig. 1. Therefore, the areas actually covered by the end cover 4 are also visible.

[0022] The battery box 1, as shown in the top view, has an approximately double-T shape and is connected, in a manner not shown, to the vehicle's electrical system via circuit boards arranged in the end cover 4 and to a battery cooling system via coolant inlet and outlet lines. The end cover 4 is preferably made of plastic.

[0023] The Fig. Figure 2 shows an exploded view of the battery box 1 with the integrated traction battery 5, which is composed of a multitude of interconnected, block-shaped cell assemblies 6 with stacked battery cells and forms, for example, a known lithium-ion high-voltage battery. The cell assemblies 6 have clamping plates 6a on their end faces, which clamp the battery cells together.

[0024] Below the cell clusters 6, as seen from above (compare Fig. 3) Rectangular cooling plates 7 are arranged, some of which are directly enclosed by the common frame 2 and some of which are additionally supported by support struts 8, forming a flat base for the traction battery 5. The cooling plates 7 have integrated cooling channels 7b ( Fig. 8) are made of light metal using the extrusion process.

[0025] The support struts 8 can be made of sheet steel or light metal and are firmly connected to the common, outer frame 2.

[0026] Frame 2 ( Fig. 4) is modularly assembled from hollow steel profiles or longitudinal and transverse beams 2a, 2b in a rigid and fluid-tight manner, wherein the beams 2a, 2b are connected to the vehicle's cooling system and form identical parts, possibly of different lengths. The longitudinal and transverse beams 2a, 2b are, as shown in the enlarged sections of the Fig. 4 shown, provided at the corner connection points with pipe fittings 2c, via which they can be telescopically inserted into one another and firmly connected to each other, for example by welding, soldering, etc.

[0027] As an alternative to the design of frame 2 according to the Fig. 4 and Fig. 5. The pipe fittings 2c can be connected to separate connecting elements 2e ( Fig. 6) are formed, either as corner connections (as shown) or as T-shaped connections (indicated by dashed lines), thus further optimizing the modular principle of frame 2.

[0028] After the frame 2 is assembled, in addition to its load-bearing function, it forms a continuous coolant channel formed by the hollow profiles 2a, 2b, which is only indicated by the arrows 9 and extends fluidically through the cooling plates 7.

[0029] On the common frame 2 or on its longitudinal and transverse beams 2a, 2b, tabs 2d projecting towards the cooling plates 7 are formed, onto which the cooling plates 7 are placed with lateral tabs 7a in overlapping areas and which are positively locked in the plane of the underbody with corresponding expansion gaps (not shown) by the frame 2.

[0030] Corresponding tabs 8a for supporting the cooling plates 7 are also provided on the support struts 8 (compare Fig. 8).

[0031] In the connection area of ​​the cooling plates 7 to the coolant guide in the frame 2 there are line connections 10 ( Fig. 5, welded into the longitudinal beams 2a and into the transverse beams 2b using the one cross member 2b), which are fluid-tight, for example by labyrinth sealing with the cooling channels 7b ( Fig. 8) communicate in the cooling plates 7, so that they are uniformly supplied with cooling medium from one longitudinal beam 2a to the other longitudinal beam 2a or, in the case of cooling plates 7 directly enclosed by the frame 2, from transverse beam 2b to transverse beam 2b.

[0032] For this purpose, flow-guiding walls (not shown) may be provided in the frame members 2a, 2b to ensure a targeted flow through the cooling plates 7.

[0033] The cell assemblies 6, mounted on the subfloor formed by the cooling plates 7 and the support struts 8, are fastened by means of screws (not shown), with the fastening points 11 shown (compare Fig. 7) each lies outside the overlap areas (tabs 2d, 7a, 8a) with the cooling plates 7, meaning they are not screwed in place and can compensate for different thermal expansions. Before placing and assembling the cell assemblies 6, the underside is provided with a thermally conductive, electrically insulating coating. This can be achieved by applying a coating or by attaching suitable insulating mats, etc.

[0034] The Fig. Figure 9 shows the underside of the battery box 1 with the common frame 2 and the intermediate frame 3 mounted on it, which, as shown, is also a single piece, but can also be made of multiple parts. The intermediate frame 3 can in turn be made of hollow steel profiles, plastic, or light metal.

[0035] The intermediate frame 3 is like the Fig. 1 and for example Fig. 5 shows, mounted on a multitude of plug pins 2f, which are attached around the frame 2 and project upwards and which engage in corresponding bores of the intermediate frame 3.

[0036] The intermediate frame 3 is according to Fig. 10a is designed such that the end cover 4, with its downward-projecting circumferential walls, can be attached to it either by pushing it on or screwing it on. For this purpose, threaded holes 3a are incorporated into the intermediate frame 3, into which corresponding fastening screws for the end cover 4 can be screwed.

[0037] According to Fig. 10b, circumferential recesses 3b are arranged on the intermediate frame 3, into which a foil 12 with thickened edge areas can be inserted, which encloses and covers the traction battery 5 with the cell assemblies 6 accordingly instead of the end cover 4.

[0038] The Fig. Figure 10c only hints at the different height design of the intermediate frame 3, such that it fits relatively closely to the underbody 13 of the motor vehicle body or is adapted to it accordingly.

[0039] In contrast to the described fastening method, the end cover 4 can also be fastened with its base wall using spacers 20 ( Fig. 2) be attached to or plugged onto the side clamping plates 6a of the cell assemblies 6 of the traction battery 5.

[0040] The Fig. Figures 12 to 13 show an alternative battery box 14, which is only shown and described insofar as it differs from the Fig. Parts 1 to 10 differ essentially. Functionally identical parts are marked with the same reference numbers.

[0041] According to Fig. 12 The common frame 2 is not only formed from longitudinal and transverse beams 2a, 2b, but also from vertical beams 2g and is designed in such a stepped manner that the rear mounting at 15 for the cell assemblies 6 is positioned higher than the front mountings for the cooling plates 7. In addition to their load-bearing function, the vertical beams 2g also act as coolant guides for cooling the traction battery 5 or its cell assemblies 6.

[0042] The central, lower-lying receptacle at 16 for the cell assemblies 6 of the traction battery 5 is further designed such that the cooling plates 7 ( Fig. 12 and Fig. 13) are arranged vertically. For this purpose, the cooling plates 7 are each mounted in a support frame 17 ( Fig. 13) inserted, which also has the fastening points 11 for fastening the cell assemblies 6 which are then rotated by 90 degrees and which is also composed of hollow profiles made of steel or light metal that conduct cooling medium.

[0043] As indicated by arrows 9, the support frames 17 and, via these, the inserted cooling plates 7 connected via pipe connections 10 are supplied with cooling medium.

[0044] The cooling plates 7 with the support frames 17 are installed as follows: Fig. 1 shows that it is attached to the longitudinal struts 2a of the frame 2 accordingly and supplied with cooling medium.

[0045] The described, upright arrangement of the cooling plates 7 with support frame 17 is also applied at the mounting point 15 for the rear cell assemblies 6, whereby the support frames 17 are inserted into the crossbeams 2b, i.e., arranged longitudinally.

[0046] Several mounting brackets 18 and / or mounting consoles 19 are welded to the frame 2 or to its longitudinal beams 2a (and possibly transverse beams 2b), which serve to fasten the battery box 1 with traction battery 5 and possibly end cover 4 to the underbody 13 of the vehicle body, for example by means of screw connections not shown.

[0047] The invention is not limited to the illustrated embodiments. Materials and manufacturing processes other than those described may also be used. Modifications between the described embodiments are also readily possible. The described intermediate frame can optionally be omitted, and the end cap can be placed directly onto frame 2. Reference symbol list 1 battery box 2 Common framework 2a Longitudinal beams 2b Crossbeams 2c pipe stub 2D tabs 2e Connecting elements 2f locking pins 2g vertical spars 3 intermediate frames 3a Threaded holes 3b In-depth sections 4 End caps 5 traction batteries 6 cell clusters 6a Chipboard 7 cooling plates 7a Tabs 7b Cooling channels 8 support struts 8a Tabs 9 arrows as coolant guides 10 pipe connections 11 attachment points 12 Cover film 13 Underbody Body 14 Battery box 15 Rear view 16 Medium shot 17 support frames 18 mounting brackets 19 mounting brackets 20 spacers

Claims

[1] Arrangement of a traction battery (5) in a motor vehicle, which is composed of several cell assemblies (6) of battery cells, wherein the cell assemblies (6) are connected at least on one side to cooling plates (7) and are received in a battery box (1; 14) to be attached to the motor vehicle, characterized by , that the cooling plates (7) through which coolant flows directly form the underside of the battery box (1; 14), that the cooling plates (7) forming the underside of the battery box (1; 14) are enclosed by a common frame (2), that the cooling plates (7) are inserted into the frame (2), and that the cooling plates (7) are connected to a coolant supply (9) via the frame (2) which has at least one closed hollow profile. [2] Arrangement according to claim 1, characterized by that the cooling plates (7), which are approximately rectangular in plan view, are aligned in the common frame (2) in the longitudinal and / or transverse direction. [3] Arrangement according to any one of the preceding claims, characterized by , that the frame (2) is formed in modular construction by several longitudinal and transverse beams (2a, 2b) which are fluid-tightly connected to each other. [4] Arrangement according to claim 3, characterized by , that the longitudinal and transverse beams (2a, 2b) are telescopically connected to each other via plug connections (2c). [5] Arrangement according to claim 3 or 4, characterized by , that the longitudinal and transverse beams (2a, 2b) are joined together via T-shaped and / or corner-shaped connecting elements (2e). [6] Arrangement according to any one of the preceding claims, characterized by , that support struts (8) are provided between adjacent cooling plates (7), which are attached to the enclosing frame (2) and which additionally support the cooling plates (7). [7] Arrangement according to claim 6, characterized by, that the support struts (8) are aligned in the longitudinal extension of the cooling plates (7) and that the cooling plates (7) rest in the longitudinal direction on the support struts (8) and / or on longitudinal beams (2a) of the frame (2) at correspondingly aligned overlap areas (2d, 7a, 8a). [8] Arrangement according to one of claims 6 and 7, characterized by , that the cell assemblies (6) of the traction battery (5) are only screwed to the frame (2) and, if applicable, the support struts (8) and that the cooling plates (7) are supported without screws between the frame rails (2a, 2b) and, if applicable, the support struts (8). [9] Arrangement according to claim 6, characterized by , that the cooling plates (7) with the support struts (8) form a flat support surface for the cell assemblies (6) of the traction battery (5). [10] Arrangement according to claim 6, characterized by, that the cooling plates (7) are made of extruded profiles made of a light metal alloy having cooling channels (7b) and the frame (2) with the support struts (8) is made of steel. [11] Arrangement according to any one of the preceding claims, characterized by , that an intermediate frame (3) is mounted on the frame (2), which serves as height compensation for a cover (4) of the traction battery (5) or for a subsequent body component (13) of the motor vehicle. [12] Arrangement according to claim 11, characterized by , that the intermediate frame (3) is attached to the frame (2) via bolt connections (2f). [13] Arrangement according to claim 11 or 12, characterized by , that the intermediate frame (3) and / or lateral clamping plates (6a) of the cell assemblies (6) support a final cover (4) of the traction battery (5) via spacers (20). [14] Arrangement according to one of claims 11 and 12, characterized by, that a foil (12) enclosing the traction battery (5) at the top can be attached to the intermediate frame (3). [15] Arrangement according to one of claims 11 and 12, characterized by , that the intermediate frame (3) is geometrically designed so that it fits snugly against the body-side underbody (13) of the motor vehicle. [16] Arrangement according to any one of the preceding claims, characterized by , that the frame (2) receiving the cell assemblies (6) is subdivided in steps into several receptacles (15, 16) supporting the cell assemblies (6) of the traction battery (5) with the cooling plates (7). [17] Arrangement according to any one of the preceding claims, characterized by , that one or more of the cooling plates (7) are inserted into the frame (2) perpendicular to the support plane of the frame (2), with the cell assemblies (6) being oriented accordingly rotated by 90 degrees. [18] Arrangement according to claim 17, characterized by, that the cooling plates (7) are inserted into support frames (17) also composed of hollow profiles, which are connected to the coolant supply (9) via the common frame (2). [19] Arrangement according to claim 18, characterized by , that the support frames (17) are only screwed to the common frame (2) and the cell assemblies (6) of the traction battery (5) and the cooling plates (7) are held in between via overlapping areas (7a). [20] Arrangement according to any one of the preceding claims, characterized by , that one or more mounting brackets (18) or mounting consoles (19) are provided on the common frame (2) for fastening the frame (2) to the underbody (13) of the body of the motor vehicle.

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