Interface for the liquid- and gas-tight connection of a battery system to a motor vehicle body

Abstract

Interface for a liquid- and gas-tight connection of a battery system (3) with a body (5) of a motor vehicle (7), wherein the interface (1) has a battery system-side first connecting element (11) with a first connection area (12) for connection to the battery system (3) and a body-side second connecting element (21) with a second connection area (22) for connection to the body (5), wherein the first and second connecting elements (11, 21) are movably connected relative to each other by means of a liquid- and gas-tight, elastic intermediate element (15).

Description

[0001] The invention relates to an interface for a liquid- and gas-tight connection of a battery system to the body of a motor vehicle. Furthermore, the invention relates to a motor vehicle comprising a battery system, a body, and such an interface. The invention also relates to a method for a liquid- and gas-tight connection of a battery system to the body of a motor vehicle by means of such an interface.

[0002] For example, DE 10 2017 206 986 A1 discloses an interface arranged between battery modules or a battery system and a motor vehicle, which includes connections such as electrical cables or a pipeline for fluid circulation. Such an interface allows the battery modules and the motor vehicle to be supplied with the electrical, hydraulic, and mechanical equipment necessary for the vehicle's functionality. The battery modules are attached to the underside of the vehicle body using a protective cover. The motor vehicle has fastening and positioning devices for positioning and aligning the battery modules, which determine their precise location and orientation. However, if errors occur—for example, due to manufacturing tolerances, bending of the fastening and positioning devices during transport, or assembly errors, etc.—they can be disturbed.Inadequate positioning and / or alignment of the battery modules can lead to connection problems between the vehicle body and the battery assembly. Furthermore, leaks can occur at the interface, which in extreme cases could endanger vehicle occupants.

[0003] Against this background, the task arises to provide an interface for connecting a battery assembly to a vehicle body that can compensate for any assembly, positioning and alignment errors of the battery assembly relative to the body.

[0004] The problem is solved by an interface for a liquid- and gas-tight connection of a battery system with a body of a motor vehicle, wherein the interface has a battery system-side first connecting element with a first connection area for connection to the battery system and a body-side second connecting element with a second connection area for connection to the body, wherein the first and second connecting elements are movably connected relative to each other by means of a liquid- and gas-tight, elastic intermediate member.

[0005] Due to the fluid-tight design of the interface according to the invention, the passenger compartment can be protected from external influences such as the ingress of gas, liquid, and / or solid particles. Furthermore, the elastic intermediate element according to the invention between the first and second connecting elements can compensate for positioning and alignment errors of the battery system, since the intermediate element, due to its elastic nature, allows relative movement between the first and second connecting elements.

[0006] According to an advantageous embodiment, the intermediate element is designed as a bellows. The bellows can be made of an elastomer such as silicone rubber to exhibit rubber-like elastic properties. Furthermore, regardless of the elasticity of the bellows material, relative movement between the two connecting elements can be enabled simply by unfolding the bellows, without compromising the sealing of the interface. Overall, tolerance compensation in all three spatial directions can be achieved between the two connecting elements, or between the battery system and the vehicle body.

[0007] A preferred embodiment of the invention provides a first sealing element for sealing against the battery system. The first sealing element can effectively seal a wet compartment, in which the battery system is arranged, against the passenger compartment. The sealing element can also be made of an elastomer.

[0008] Another preferred embodiment of the invention provides a second sealing element for sealing against the vehicle body. This second sealing element can also be made of an elastomer and separates the passenger compartment from the wet area. The second sealing element can, in particular, be used simultaneously with the first sealing element, thus increasing the overall tightness of the interface. Furthermore, the spatial distance between the first and second sealing elements can create a gap, which can lead to a further increase in the sealing effect. Particles and fluids that may have passed through the first sealing element can become trapped and deposited in this gap.

[0009] An advantageous embodiment of the invention provides that the intermediate member and the first sealing element are formed in one piece. This one-piece construction can eliminate an additional manufacturing step, since only one part is produced instead of two. Similarly, an assembly step can be omitted. Overall, this saves manufacturing time.

[0010] A further advantageous embodiment of the invention provides that the intermediate member and the second sealing element are formed in one piece. Analogous to the one-piece formation of the intermediate member and the first sealing element, the one-piece design of the intermediate member and the second sealing element saves manufacturing steps and thus time.

[0011] A particularly preferred embodiment provides that the intermediate member, the first sealing element, and the second sealing element are formed in one piece. The highest manufacturing and assembly efficiency can be achieved by forming the intermediate member, the first sealing element, and the second sealing element in one piece. This is equivalent to the intermediate member encompassing both the first and second sealing elements.

[0012] According to a preferred embodiment, the bellows is arranged at least partially along a first outer contour of the first connecting element, and the second connecting element is arranged at least partially along a second outer contour of the bellows. By arranging the bellows along an outer contour of the first connecting element, the orientation of the first connecting element relative to the second connecting element can be changed in several spatial directions by forming folds in the bellows. Furthermore, in such an arrangement, the bellows can be understood as an extension of the first connecting element, thereby enabling a greater utilization of surface area and volume between the battery system and the vehicle body, thus contributing to the sealing of the interface.Furthermore, the bellows can be connected to an inner contour of the second connecting element via an outer contour. This arrangement allows for a hermetic connection between the first and second connecting elements.

[0013] An advantageous embodiment of the invention provides that the first connecting element has at least one through-hole. Through this through-hole, the battery system can at least partially project through the first connecting element of the interface, for example, to enable the electrical connection of the battery system to the vehicle via suitable connectors through the projecting section of the battery system. Furthermore, several through-holes can be formed in the first connecting element, for example, to guide high-voltage and low-voltage cables through separate recesses in the interface.

[0014] A preferred embodiment provides a first sealing element for sealing against the battery system, which is arranged on an inner contour defined by the through-hole. By arranging a sealing element – ​​particularly an elastic one – on the inner contour, the interface can ensure an effective seal against the battery system. The sealing effect can be achieved through physical contact between the sealing element and the section of the battery system projecting through the through-hole.

[0015] According to an advantageous embodiment, the first connecting element has at least one at least partially tubular connection for the flow of a liquid medium – in particular, a cooling medium – wherein the connection is formed integrally with the first connecting element. Since battery systems in motor vehicles require thermal management, such connections may be necessary for temperature control of the battery system. A cooling medium, which can be conveyed through suitable pipes, can flow through the interface via a first coolant connection towards the battery system. The cooling medium, warmed by circulation, can then flow through the interface in the opposite direction via a second coolant connection.

[0016] An advantageous embodiment of the invention provides that the first and second connecting elements are made of a glass fiber reinforced plastic (GFRP), in particular polyamide 66 with a glass fiber content of 25% (PA66 GF25). The use of PA66 GF25 allows for good properties regarding electrical insulation, chemical corrosion resistance, and strength of the connecting elements attached to the battery system and the vehicle body, as required for the application according to the invention. Furthermore, a glass fiber reinforced plastic with polyamide 66 and a glass fiber content of 25% exhibits flame-retardant properties.

[0017] A preferred embodiment provides that the interface is manufactured using a multi-component injection molding process. With this process, the bellows can be injection-molded onto the previously molded first and second connecting elements, creating a one-piece interface. Subsequent assembly steps are eliminated, as the bellows does not need to be separately pulled onto the connecting elements and screwed, glued, or otherwise joined to them.

[0018] A further aspect of the invention is a motor vehicle comprising a battery system, a body, and an interface according to one of the preceding embodiments. Such a motor vehicle can be operated with an electric drive system. Furthermore, the battery system can be easily connected to the motor vehicle using the interface, which is fault-tolerant with respect to orientation. A good seal can also be achieved between the battery system and the motor vehicle. In addition, the interface can be made, at least partially, of materials with flame-retardant properties, thus preventing the ingress of flames into the passenger compartment, at least temporarily.

[0019] A further object of the invention is a method for connecting a battery system to a motor vehicle body in a liquid- and gas-tight manner by means of an interface comprising a first connecting element on the battery system side with a first connection area for connection to the battery system and a second connecting element on the body side with a second connection area for connection to the body, wherein the first and second connecting elements are movably connected relative to each other by means of a liquid- and gas-tight, elastic intermediate member, wherein in a first connection step the first connection area is connected to the battery system, wherein in an alignment step following the first connection step the battery system and the interface connected to the battery system are aligned with respect to the body.wherein, in a second connection step following the alignment step, the second connection area of ​​the interface is connected to the body of the motor vehicle.

[0020] This method simplifies the connection of the battery system to the vehicle, as any misalignment of the battery system can be compensated for by the interface, eliminating the need for repeated alignment and positioning of the battery system and potentially saving time. Furthermore, assembly can be simplified because the pre-assembly of the interface or the first connecting element on the battery system means that the entire interface assembly does not need to be carried out in a space-constrained body environment.

[0021] Further details and advantages of the invention will be explained below with reference to the exemplary embodiment shown in the drawings. This shows: Fig. 1a an interface according to the invention in a perspective view from above; Fig. 1b the interface according to the invention from the Fig. 1a in a perspective view from below; Fig. 2. The interface in the assembled state in a schematic representation; Fig. 3. A battery system in a schematic representation; and Fig. 4 the alignment of the battery system Fig. 3 compared to the body of a motor vehicle immediately before its assembly on the body in a schematic representation.

[0022] In the Fig. 1a and Fig. Figure 1b shows interface 1 in a perspective view from both above and below. Interface 1 has a trough-shaped base and comprises a first connecting element 11 and a second connecting element 21. Both connecting elements 11 and 21 are made of the glass fiber reinforced plastic polyamide 66 with a glass fiber content of 25%.

[0023] The first connecting element 11 comprises a first connection area 12. In the first connection area 12, the first connecting element 11 has several, here four, steel bushings 24 with threaded inserts for a screw connection. The first connecting element 11 is connected to the battery system 3 via the first connection area 12 using the bushings 24 and screws.

[0024] The second connecting element 21 has a second connection area 22. In the second connection area 22, the second connecting element 21 has several, here eight, steel bushings 24 with threaded inserts for a screw connection. The second connecting element 21 is connected to a body 5 of a motor vehicle 7 via the second connection area 22 using the bushings 24 and screws.

[0025] The two connecting elements 11 and 21 were partially overmolded with silicone using a two-component injection molding process. The silicone is partially formed as a bellows 15. Due to its folds and elastic properties, the bellows 15 allows relative movement between the first connecting element 11 and the second connecting element 21 in all three spatial directions. Furthermore, the first connecting element 11 has a first through-hole 41 and a second through-hole 42. The first connecting element 11 has a first sealing element 31 at the outer edge of the first through-hole 41. The second connecting element 21 also has a second sealing element 32, which is formed on a surface section of the second connecting element 21 and is arranged in a largely rectangular shape. The bellows 15, the first sealing element 31, and the second sealing element 32 are formed as a single piece.

[0026] Two coolant connections 50 are arranged on the first connecting element 11 and are formed integrally with it. The left of the two connections 50 serves to supply coolant to the battery system 3. The right connection 50 serves to discharge coolant from the battery system. To avoid a massive construction and thus save weight, as well as to increase the mechanical stability of the interface 1, stiffening elements 45 are provided at suitable locations.

[0027] In the Fig. 2 is the interface 1 by means of four screws 60 with the one in the Fig. The interface 1 seals a wet compartment 62 located outside the passenger compartment from a dry compartment 64 within the passenger compartment. For sealing purposes, the first and second sealing elements 31 and 32 are arranged at the interface 1. The first sealing element 31 is located on an inner contour of the interface 1, the inner contour of which is defined by the first through-hole 41. A housing section 66 of the battery system 3 projects through the first through-hole 41 of the interface 1. To achieve the sealing effect against the wet compartment 62 on the battery side, the first sealing element 31 rests directly against the housing section 66. The second sealing element 32 seals via a connection of the interface 1 – via the second connection area 22 – to the [unclear - possibly referring to the] Fig. 2. The bodywork 5 of the motor vehicle 7 is arranged above. A further sealing effect is achieved by the bellows 15, since the bellows 15 prevents the penetration of solid, liquid and / or gaseous substances, in particular flames and smoke, from the wet room 62 into the dry room 64 and thus supports the sealing.

[0028] The one in Fig. The two left-hand connections 50 supply a cooling medium to the battery system 3 for cooling battery modules. After flowing through the battery system 3, the cooling medium is dissipated for heat transfer by the [unclear text] in the Fig. The second right-hand connection 50 carries the load. Furthermore, a low-voltage cable 68 is guided through the second through-hole 42. The low-voltage cable 68 is attached to the interface 1 by means of a funnel-shaped connector 70. The connector 70 also serves as a sealing element in the interface 1. Furthermore, in the Fig. Figure 2 shows a high-voltage connection 72, which is located on the battery system 3.

[0029] In the Fig. Figure 3 shows the battery system 3 schematically in a perspective view. The interface 1 is connected by means of the first connecting element 11 and several, here four, screws via the in Fig. 3 first connection area 12 not shown connected to the battery system 3.

[0030] In the Fig. Figure 4 indicates the positioning and orientation of the battery system 3 relative to the body 5 of the vehicle 7. During pre-assembly, interface 1 was already connected to the battery system 3. In the so-called "marriage," the battery system 3 is connected to the body 5 by moving the battery system 3 and the body 5 relative to each other along the dashed lines. Reference symbol list 1 interface 3 battery system 5 Bodywork 7 Motor vehicle 11 first connecting element 12 first connection area 15 Intermediate link, bellows 21 second connecting element 22 second connection area 24 sockets 31 first sealing element 32 second sealing element 41 first through hole 42 second through hole 45 stiffening elements 50 connections 60 screws 62 Wet room 64 Drying room 66 Housing section 68 Low-voltage line 70 connector 72 High-voltage connection QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 102017206986 A1

[0002]

Claims

[1] Interface (1) for a liquid- and gas-tight connection of a battery system (3) with a body (5) of a motor vehicle (7), wherein the interface (1) has a battery system-side first connecting element (11) with a first connection area (12) for connection to the battery system (3) and a body-side second connecting element (21) with a second connection area (22) for connection to the body (5), wherein the first and second connecting elements (11, 21) are movably connected relative to each other by means of a liquid- and gas-tight, elastic intermediate element (15). [2] Interface (1) according to claim 1, characterized by , that the intermediate element (15) is designed as a bellows (15). [3] Interface (1) according to one of the preceding claims, characterized by a first sealing element (31) for sealing against the battery system (3). [4] Interface (1) according to claim 3, characterized bya second sealing element (32) for sealing against the body (5). [5] Interface (1) according to claim 3, characterized by , that the intermediate member (15) and the first sealing element (31) are formed in one piece. [6] Interface (1) according to claim 4, characterized by , that the intermediate member (15) and the second sealing element (32) are formed in one piece. [7] Interface (1) according to claim 4, characterized by , that the intermediate member (15), the first sealing element (31) and the second sealing element (32) are formed in one piece. [8] Interface (1) according to any one of claims 2 to 7, characterized by , that the bellows (15) is arranged at least partially along a first outer contour of the first connecting element (11), wherein the second connecting element (21) is arranged at least partially along a second outer contour of the bellows (15). [9] Interface (1) according to any of the preceding claims, characterized by that the first connecting element (11) has at least one through hole (41). [10] Interface (1) according to claim 9, characterized by a first sealing element (31) for sealing against the battery system (3), which is arranged on an inner contour defined by the through hole (41). [11] Interface (1) according to any of the preceding claims, characterized by , that the first connecting element (11) has at least one at least partially tubular connection (50) for the flow of a liquid medium - in particular cooling medium - wherein the connection (50) is formed integrally with the first connecting element (11). [12] Interface (1) according to any of the preceding claims, characterized by , that the first and second connecting elements (11, 21) are made of a glass fiber reinforced plastic (GFRP), in particular of polyamide 66 with a glass fiber content of 25% (PA66 GF25). [13] Interface (1) according to any of the preceding claims, characterized by , that the interface (1) is manufactured using a multi-component injection molding process. [14] Motor vehicle (7) comprising a battery system (3), a body (5) and an interface (1) according to any of the preceding claims. [15] Method for connecting a battery system (3) to a body (5) of a motor vehicle (7) in a liquid- and gas-tight manner by means of an interface (1) which has a first connecting element (11) on the battery system side with a first connection area (12) for connecting to the battery system (3) and a second connecting element (21) on the body side with a second connection area (22) for connecting to the body (5), wherein the first and second connecting elements (11, 21) are movably connected relative to each other by means of a liquid- and gas-tight, elastic intermediate element (15), wherein in a first connection step the first connection area (12) is connected to the battery system (3), wherein in an alignment step following the first connection step the battery system (3) and the interface (1) connected to the battery system (3) are aligned with respect to the body (5), wherein in a second connection step following the alignment step the second connection area (12) of the interface (1) is connected to the body (5) of the motor vehicle (7).