Traction battery for a motor vehicle and method for producing such a traction battery

Abstract

Traction battery (100) for a motor vehicle, with - a battery housing (110); and - at least one battery module (120) arranged in the battery housing (110), which has a plurality of battery cells (121) combined to form a cell stack; wherein the battery module (120) is positively connected to a base element (111) and a cover element (112) of the battery housing (110) by means of connecting elements (124, 130), characterized by that the base element (111) has a plurality of positioning pins (124) and the battery module (120) is formed with corresponding recesses into which the positioning pins (124) engage in a form-fitting manner in order to bring about an alignment of the battery module (120) in the battery housing (110), and that in addition the battery module (120) is screwed to the base element (111) and the cover element (112) of the battery housing (110) by means of screws (130), wherein the screws (130) are guided from the outside through the base element (111) and through the cover element (112) and corresponding threaded bushings are arranged on the battery module (120) in order to fasten the battery module (120) in the battery housing (110).

Description

[0001] According to the preamble of claim 1, the invention relates to a traction battery for a motor vehicle, comprising a battery housing and at least one battery module arranged inside the battery housing, which module comprises a plurality of battery cells combined to form a cell stack. The invention further relates to a method for producing such a traction battery.

[0002] A battery module with several battery cells combined to form a cell stack is known, for example, from WO 2012 / 009145 A2.

[0003] The closest patent application, DE 10 2020 112 434 A1, describes a traction battery for a motor vehicle and a method for manufacturing a traction battery. A battery housing of the traction battery has a housing base and a housing cover, between which there is a receiving compartment for accommodating one or more cell modules fastened to one another. The housing base and the housing cover are clamped to the cell modules arranged in the receiving compartment. The clamping is achieved by means of several screws, which engage the housing base on the one hand and the housing cover on the other.

[0004] Regarding the state of the art, reference is also made to DE 10 2004 042 326 A1, US 2007 / 0087266 A1, DE 10 2017 209 524 A1, DE 10 2016 222 824 A1 and DE 10 2020 129 785 A1.

[0005] The object of the invention is to show a further possibility of how a battery module consisting of several battery cells combined to form a cell stack can be arranged and fastened in a battery housing in a comparatively simple and space-saving manner.

[0006] This object is achieved with the traction battery according to the invention as defined in claim 1. The independent claim also extends the invention to a method for producing such a traction battery. Advantageous developments and refinements of the invention are evident for both subject matters of the invention from the dependent claims, the following description of the invention (this expressly includes features described as examples and optionally), and the figures.

[0007] The traction battery (drive battery) according to the invention comprises a battery housing or a battery box and at least one battery module arranged in the battery housing, ie in the interior of the battery housing, which has a plurality of battery cells combined to form a cell stack, wherein the (at least one) battery module is positively connected to a base element and a cover element of the battery housing by means of connecting elements.

[0008] The battery housing or battery box has, in particular, a trough-shaped lower part with a base element and a side wall surrounding it, as well as an upper part with a cover element, wherein the upper part is designed, in particular, as a lid. The base element and / or the cover element is preferably flat and, in particular, plate-like. The base element and / or the cover element is preferably made of plastic, in particular of thermoplastic plastic, wherein preferably a short-fiber-reinforced plastic, in particular a short-fiber-reinforced thermoplastic plastic, is provided. The base element and / or the cover element is, in particular, an injection-molded part or a compression-molded part. The base element and / or the cover element can also be a conventional fiber composite component (FRP component) with a reinforcing fiber textile or the like embedded in a thermosetting or thermoplastic plastic matrix.Preferably, the entire battery housing, including the side wall, is made of plastic. The battery housing can also have a rack or frame structure, in particular a ladder frame structure. The frame structure is preferably made of plastic, in particular of thermoplastic, with a short-fiber-reinforced plastic, in particular a short-fiber-reinforced thermoplastic, preferably being provided. The frame structure is in particular an injection-molded part or a compression-molded part. The battery housing is in particular designed as a sealed battery housing.

[0009] The battery module (module stack) has a plurality of battery cells arranged to form a cell stack. These are preferably prismatic, in particular cuboid-like, battery cells. The battery cells are preferably held together by at least one tensioning strap or a tensioning frame or a clamping rack. So-called end or pressure plates are also preferably provided, which are arranged on the opposite end faces of the cell stack. Furthermore, at least one intermediate plate can also be provided, which is arranged between adjacent groups, each with a specific number of stacked battery cells. The battery module preferably has a cuboid-like shape. The battery module is in particular a so-called high-voltage module (HV module). The battery module is preferably arranged horizontally in the battery housing, i.e. the stacking direction is horizontal.The traction battery can comprise multiple battery modules, which can be identical or different in design. Further explanations relating to one battery module apply analogously to a multitude of battery modules.

[0010] According to the invention, (a plurality of) connecting elements are provided which form-fittingly connect the battery module to a base element and a cover element of the battery housing, whereby the battery module is aligned and secured in the battery housing. Similarly, a form-fitting connection to a frame structure (see above) can also be provided by means of the connecting elements, to which the following explanations apply analogously. In particular, it is provided that the connecting elements bring about a quasi-direct form-fitting connection between the battery module and the base or cover element of the battery housing without the integration of further elements or components. This allows the required installation space to be reduced or the available installation space to be better utilized, so that, for example, more space is available for the battery cells. Furthermore, assembly advantages can also result.Suitable connecting elements are, in particular, screw connecting elements or plug-in connecting elements (see below), which are suitably matched to one another.

[0011] The floor element and in particular also the ceiling element has a plurality of (internally arranged) positioning pins, wherein the battery module is formed with corresponding recesses into which the positioning pins protrude or engage in a form-fitting manner. The positioning pins are preferably conical. The positioning pins can have a height of 5 mm to 30 mm. The recesses are preferably adapted in shape and depth to the positioning pins. The positioning pins and the recesses are connecting elements (plug-in connection elements) which, in particular in the horizontal plane (i.e. in the xy plane of the vehicle coordinate system), align the battery module in the battery housing and, if necessary, also hold the battery module. Furthermore, assembly is simplified. Similarly, an interchanged arrangement is also possible for individual or all positioning pins and recesses, i.e.The positioning pins are arranged on the battery module and the corresponding recesses on the floor or ceiling element.

[0012] As already explained above, the floor element and / or the ceiling element is preferably made of plastic. Preferably, the positioning pins are also made of plastic, in particular of the same plastic, and are molded onto the floor or ceiling element. This means, in particular, that the floor or ceiling element, including the positioning pins, is manufactured in one piece, preferably as an injection-molded or compression-molded part.

[0013] The battery module is also screwed to the base element and the cover element of the battery housing. The screw connection is carried out by means of (several) screws which are passed through the base element and the cover element from the outside, i.e. from below or from above. Corresponding threaded bushings or the like are arranged on the battery module. The screws and the threaded bushings are connecting elements (screw connecting elements) which fasten the battery module in the battery housing. At the screw connection points, the base or cover element is preferably designed with through holes or bores, preferably with edge-reinforced through holes, for the screws, which were created in particular during the manufacture of the base or cover element. The through holes can also be reinforced with a sleeve, in particular a metallic sleeve.Preferably, at least one seal is also provided at each through-hole to seal the screw connection point. The seal can be arranged in a ring around the through-hole on the inside and / or outside and can, in particular, be glued or sprayed onto the floor or ceiling element. The seal can also be arranged on the battery module side, i.e., around the threaded bushing.

[0014] The battery module can have at least one end or pressure plate (see above), at least one intermediate plate (see above) and / or at least one side part, which is in particular a component of a clamping frame or clamping rack (see above). These components or components are preferably made of plastic, in particular of thermoplastic plastic, optionally also with short fiber reinforcement, or of metal, in particular aluminum. They are preferably injection-molded parts, press-molded parts or die-cast parts. The components in question can also be conventional fiber composite components (see above). It is preferably provided that the battery module is positively connected to the base element and / or the cover element of the battery housing by means of connecting elements at least on one such component, i.e. at least one end plate and / or at least one intermediate plate and / or at least one side part.A respective component can be designed with a plurality of recesses, at least with at least one recess, for the engagement of positioning pins and / or with a plurality of threaded bushings, at least at least one threaded bushing, for the engagement of screws. Preferably, two positioning pins are provided for each component (i.e. end plate, intermediate plate or side part) on which an alignment of the battery module takes place, i.e. the positioning pins are preferably arranged in pairs, the same applying to the recesses. The recesses are preferably designed as depressions. The threaded bushings are preferably designed as inserts, in particular as metallic inserts. Preferably, the recesses and / or threaded bushings were produced or integrated during the manufacture of the respective component.Preferably, the alignment and / or fastening of the battery module in the battery housing is carried out using the connecting elements exclusively on at least one end plate and / or on at least one intermediate plate and / or on at least one side panel. In particular, the alignment and / or fastening of the battery module in the battery housing is carried out using the connecting elements on each end plate and / or on each intermediate plate and / or on each side panel.

[0015] Preferably, the battery module is also screwed to the side wall of the battery housing, in addition to the screw connection to the base element and the cover element. Analogous to the preceding explanations, the screw connection is preferably implemented by means of (several) screws which are passed through the side wall from the outside, i.e. from the side. At the screw connection points, the side wall is preferably formed with (lateral) through-holes or bores. Corresponding or corresponding threaded bushings or the like are preferably arranged on the battery module. The screw connection is carried out in particular with at least one end plate, at least one intermediate plate and / or at least one side part of the battery module (which adjoins the side wall), which for this purpose can be designed with at least one threaded bushing for the engagement of a screw. The threaded bushing is in particular a metallic insert.Preferably, at least one seal is also provided at each (lateral) through-hole to seal the screw connection point. The seal can be arranged on the inside and / or outside around the through-hole and can, in particular, be glued or sprayed onto the side wall. The seal can also be arranged on the battery module side, i.e., around the threaded bushing.

[0016] The method according to the invention for producing or assembling a traction battery comprises at least the following steps: - arranging, in particular automated arranging, the at least one battery module in the (open) battery housing, in particular in a trough-shaped lower part of the battery housing, which of course requires the provision of the battery housing or its parts and at least one pre-assembled battery module; - Closing the battery housing, in particular by placing or mounting an upper part onto the lower part.

[0017] According to the invention, the battery module is positively connected to a base element and a cover element of the battery housing by means of connecting elements during its placement in the battery housing and thereafter, i.e., before and / or after the battery housing is closed. Reference is made to the preceding and following explanations, which apply analogously to the method according to the invention.

[0018] When it is arranged in the battery housing, in particular when it is inserted into a trough-shaped lower part of the battery housing, the (at least one) battery module is aligned or positioned in a defined manner by means of the positioning pins arranged (on the inside) on the base element of the battery housing or the lower part, in that the positioning pins engage positively in the corresponding recesses on the battery module. After that, i.e. before and / or after the battery housing is closed, the battery module is fastened to the base element and the cover element and, if applicable, also to the side wall of the battery housing by screwing using screws. The prior alignment of the battery module also ensures alignment at the screwing points between the at least one component of the battery module to be screwed (e.g.End plate, intermediate plate, and / or side panel) and the battery housing, simplifying subsequent screwing. Further reference is made to the preceding and following explanations.

[0019] The invention is also suitable for other battery systems of a motor vehicle, e.g. for a starter battery.

[0020] Within the scope of the invention, both the features described above and those explained below are applicable not only in the respective combination of features specified, but also in other combinations of features or in isolation. This also applies to the features shown in the figures.

[0021] The invention is explained in more detail below in a non-limiting manner with reference to the figures. The same reference numerals are used for the same components throughout the figures. The possible embodiments shown in the figures, in particular those shown in Fig. 1 and Fig. 2 shown design options can be combined. Fig. 1 shows a sectional view of one possible design of the traction battery. Fig. 2 shows a sectional view of another possible embodiment of the traction battery with positioning pins provided according to the invention. Fig. 3 shows a sectional view of a screw connection point on the traction battery of the Fig. 1 or Fig. 2.

[0022] The Fig. The traction battery 100 shown in Figure 1 has a sealed battery housing or a battery box 110, which comprises a base element 111, a cover element 112, and a side wall 113 formed from side wall elements. Several battery modules are arranged inside the battery housing 110, which are thus located above the base element 111 and below the cover element 112. The sectional view shows a battery module 120, which comprises several (horizontally) stacked or arranged to form a cell stack prismatic battery cells 121, two end or pressure plates 122, and several middle or intermediate plates 123, which extend perpendicular to the plane of the illustration. The battery module 120 is held together by at least one tensioning strap (not shown) or a tensioning frame (not shown) or the like, and thus forms a preassembled structural unit.The battery module 120 is screwed to the base element 111, the cover element 112, and the side wall 113 of the battery housing 110, thereby securing it in the battery housing 110. The screw connection from below and above and the resulting mechanical coupling create a sandwich effect, which is beneficial for the mechanical rigidity of the battery housing 110. The screw connection is only present at the end plates 122 and intermediate plates 123, and possibly also at the side panels of a clamping frame (see . Fig. 2). The screw connection is made using screws 130, which are passed through through bores or holes and engage in threaded bushings provided for this purpose (see Fig. 3).

[0023] The Fig. The battery module 120 shown in Figure 2 has two side parts 125 that extend in the stacking direction of the battery cells 121 and perpendicular to the plane of the illustration. The profile-like side parts 125, which can each also be formed in multiple parts (e.g., as an upper and lower side part), are components of a clamping frame or clamping rack with which the battery cells 121 and, if applicable, any end and intermediate plates are combined and held together. The battery cells 121 and any end and intermediate plates extend parallel to the plane of the illustration. The base element 111 and the cover element 112 of the battery housing 110 are formed on the inside with positioning pins 124 that protrude in the z-direction and protrude or engage in a form-fitting manner in corresponding recesses in the side parts 125, whereby the battery module 120 is aligned and held in the battery housing 110.Furthermore, the battery module 120 is screwed to the base element 111 and the ceiling element 112 at the side parts 125 by means of screws 130. The side parts 125 are formed with corresponding threaded bushings. Advantageously, both the positioning pins 124 and the screw connection points are arranged such that sufficient space is available below the battery cells 121 for a cooling and / or heating device. The side parts 125 can also be screwed to the adjacent side wall 113 of the battery housing 110. In a similar manner, positioning pins can be provided on the base or ceiling, which protrude into corresponding recesses on the end or intermediate plates. The positioning pins 124 and the corresponding recesses can also be referred to as first connecting elements. The screws 130 and the corresponding threaded bushings can also be referred to as second connecting elements.The positions of the connecting elements and through holes are self-explanatory and coordinated with each other.

[0024] As already mentioned above, the battery housing 110 can also have a frame structure or frame construction or the like. Analogously to the preceding explanations, a positive alignment and / or fastening of the (at least one) battery module 120 to this frame structure can then be effected.

[0025] At the Fig.At the screw connection point shown in Figure 3, the base element 111 of the battery housing 110 has a through-hole or through-bore 115. The through-hole 115 is reinforced at the edge by means of a dome and also has a sleeve 116, in particular a metallic sleeve. The dome can also be arranged on the inside. The component to be screwed tight, which can be an end plate 122, an intermediate plate 123, or a side part 125, has a threaded bushing 126 at the screw connection point, which is preferably designed as an insert 127, in particular as a metallic insert. To seal the through-hole 115, an internal seal 117 and / or an external seal 118 is provided. Alternatively or additionally, a seal 128 can also be provided on the component 122, 123, 125 to be screwed tight.The seals 117, 118, 128 can be designed as separate O-ring seals and / or as glued or sprayed-on seals and are preferably made of PUR, butyl, or EPDM. Alternatively or additionally, a seal can also be arranged on the sleeve 116 and / or on the screw 130, particularly on the underside of the head. Preferably, all screw connection points are designed similarly. So-called FDS screws (Flow Drill Screws) can also be used as screws 130, with which the through hole 115 and / or the threaded bushing 126 can be created directly during the screwing process.

Claims

[1] Traction battery (100) for a motor vehicle, with - a battery housing (110); and - at least one battery module (120) arranged in the battery housing (110), which has a plurality of battery cells (121) combined to form a cell stack; wherein the battery module (120) is positively connected to a base element (111) and a cover element (112) of the battery housing (110) by means of connecting elements (124, 130), characterized by , that the base element (111) has a plurality of positioning pins (124) and the battery module (120) is formed with corresponding recesses into which the positioning pins (124) engage in a form-fitting manner in order to bring about an alignment of the battery module (120) in the battery housing (110), and that in addition the battery module (120) is screwed to the base element (111) and the cover element (112) of the battery housing (110) by means of screws (130), wherein the screws (130) are guided from the outside through the base element (111) and through the cover element (112) and corresponding threaded bushings are arranged on the battery module (120) in order to fasten the battery module (120) in the battery housing (110). [2] Traction battery (120) according to claim 1, characterized by , that the ceiling element (112) also has several positioning pins (124), wherein the battery module (120) is formed with corresponding recesses into which the positioning pins (124) engage in a form-fitting manner. [3] Traction battery (100) according to claim 1 or 2, characterized bythat the floor element (111) and / or the ceiling element (112) is made of plastic and that the positioning pins (124) are then also made of plastic and are molded onto the floor element (111) or onto the ceiling element (112). [4] Traction battery (100) according to one of the preceding claims, characterized by that the floor element (111) and the ceiling element (112) are formed with through holes (115) for the screws (130), wherein at least one seal (117, 118, 128) is also provided at each through hole (115). [5] Traction battery (100) according to one of the preceding claims, characterized by that the battery module (120) has at least one end plate (122), at least one intermediate plate (123) and / or at least one side part (125), which is formed with a plurality of recesses for the engagement of positioning pins (124) and / or with a plurality of threaded bushings (126) for the engagement of screws (130). [6] Traction battery (100) according to one of the preceding claims, characterized by that the battery module (120) is also screwed to a side wall (113) of the battery housing (110). [7] A method for manufacturing a traction battery (100) according to any one of the preceding claims 1 to 6, comprising the following steps: - arranging the at least one battery module (120) in the battery housing (110), wherein the battery module (120) is aligned by means of the positioning pins (124) arranged on the base element (111) of the battery housing (110), in that the positioning pins (124) engage positively in the corresponding recesses on the battery module (120); - closing the battery housing (110), wherein before and / or after closing the battery housing (110) the battery module (120) is fastened to the base element (111) and to the ceiling element (112) and optionally also to the side wall (113) of the battery housing (110) by screwing using screws (130).

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