Electrically or partially electrically powered motor vehicle with a sealing arrangement for sealing an assembly gap against a degassing chamber

Abstract

The invention relates to an electrically or partially electrically powered motor vehicle with a sealing arrangement for sealing an assembly gap against a degassing chamber. An assembly gap (70) is located between a connecting component (80) and a battery module housing (22), wherein a sealing arrangement is provided for sealing the assembly gap (70) against a degassing chamber (50), the sealing arrangement comprising a sheet metal strip (62) extending along the assembly gap (70), the sheet metal strip (62) having a first end section (64) facing the battery module (20), a second end section (65) facing the connecting component (80), and a folded section connecting the first end section (64) to the second end section (65), the folded section having a fold (67) extending into the assembly gap (70) with a first leg (68) and a second leg (69) bent in the opposite direction.wherein the sheet metal strip (62) is bonded sealingly to the battery module housing (22), wherein the second end section (65) is connected to the connecting component (80), wherein the sealing arrangement comprises a sealing element (61), wherein the sealing element (61) is arranged between the sheet metal strip (62) and the underbody protection plate (30) and interacts sealingly with the sheet metal strip (62) and the underbody protection plate (30).

Description

[0001] The invention relates to an electrically or partially electrically powered motor vehicle with a sealing arrangement for sealing an assembly gap against a degassing chamber.

[0002] In electrically or partially electric vehicles, numerous battery cells, such as lithium-ion cells, are connected to form a traction battery, also known as a high-voltage battery. Such a traction battery typically consists of several hundred, sometimes up to several thousand, battery cells. The battery cells of the traction battery are usually connected to form battery modules, or subgroups, with each module typically containing an identical number of battery cells. The battery cells are generally stacked in a single direction to form a cell stack, which is then inserted into a battery module housing.

[0003] Due to malfunctions, a battery cell can overheat, causing the electrolyte to vaporize and rapidly increase the pressure inside the cell. To prevent uncontrolled rupture of the cell casing or housing, it is known to equip battery cells with a safety valve that opens at a predetermined internal cell pressure, allowing the vaporized electrolyte and any other decomposition products to escape. This process is also known as degassing. The safety valve can be formed by an opening in the cell casing sealed with a rupture disc that bursts at a defined pressure, thus releasing the valve opening.

[0004] The gases released during degassing are usually at high temperatures, typically in the range of 500°C to 1200°C. Temperatures exceeding 1200°C can also occur. These gases must be extracted from the battery system or traction battery and vented from the vehicle in such a way as to prevent any danger to vehicle occupants, other vehicle components, and objects or people in the vicinity of the vehicle. A particular problem with these hot gases is their high temperature, which can destroy or at least damage components made of insufficiently heat-resistant materials that come into contact with them. Furthermore, these gases can ignite and cause a flame if they come into contact with oxygen, such as from the ambient air, in high concentrations.It is essential to prevent flames from forming outside the vehicle during degassing. This requires avoiding immediate, uncontrolled outgassing.

[0005] Many electric or hybrid vehicles have an underfloor battery, also known as a traction battery, located in the vehicle's underbody. A protective underbody panel is typically positioned beneath this traction battery to shield it from external influences, particularly mechanical damage. This underbody panel serves various purposes, including protecting the battery when driving over obstacles such as speed bumps, from stone chips, and acting as a bollard guard.

[0006] Particularly in electrically or partially electrically powered vehicles with an underfloor battery, in the event of a thermal event in one of the battery cells and the associated outgassing, it is typically provided that the resulting hot gas is discharged downwards from the traction battery or a component of the traction battery, such as a battery module housing. DE 10 2022 108 822 B3 discloses a vehicle with an electrical energy storage device and an underbody protection plate located beneath it. The energy storage device is to be arranged in a battery housing with at least one fluid outlet opening. Flow channels are provided between the battery housing and the underbody protection plate, as well as within the underbody protection plate itself.The flow channels are formed by spacers between the battery housing and the underbody protection plate, as well as between the layers of the underbody protection plate, which may have a meandering shape. Inlet and outlet openings can be located centrally, laterally, at the front, or at the rear of the vehicle.

[0007] DE 10 2023 100 561 B3 discloses a motor vehicle which has the features of the preamble of claim 1. The motor vehicle has an underfloor battery and an underbody protection plate with a multi-layered structure, namely a reinforcing layer made of a heat-resistant material, a first fiber composite layer and a second fiber composite layer, wherein the reinforcing layer is formed between the first fiber composite layer and the second fiber composite layer.

[0008] In DE 10 2022 108 822 B3 and DE 10 2023 100 561 B3, it is provided that in the event of degassing of one or more of the battery cells or in the event of a thermal event, the escaping hot gas flows into the designated degassing chamber between the underfloor battery and the underbody protection plate in order to prevent or at least delay contact with ambient air and the associated flame formation. Preferably, the degassing chamber serves to cool the gas sufficiently before contact with the ambient air to prevent flame formation. For this purpose, labyrinthine or meandering flow channels may also be provided in the degassing chamber.A problem with the degassing chamber is that, firstly, a high degree of airtightness must be ensured in the connection between the underbody protection panel and the underbody battery. Secondly, it must exhibit high mechanical strength, as significant forces are exerted during degassing due to pressure surges. These pressure surges can be so intense that the underbody protection panel bulges towards the road surface. This can place considerable stress on sealing areas, potentially leading to seal failure. This, in turn, can result in the unwanted release of gas and the formation of an unwanted flame. Furthermore, with current sealing designs between the underbody protection panel and the underbody battery, removing and replacing the underbody protection panel is usually a complex and costly process, as it is often bonded to the underbody battery for sealing purposes.

[0009] EP 4 336 633 A1, DE 10 2017 005 328 B4 and EP 4 326 570 A1 reveal further state of the art.

[0010] The object of the present invention is to further develop a motor vehicle having features of the preamble of claim 1 with regard to the sealing concept, in such a way that a particularly stable seal of the degassing space formed between the underfloor battery and the underfloor protection plate to an assembly gap is ensured even in the case of relative movements.

[0011] This problem is solved by the object that has the features of claim 1. The dependent claims relate to advantageous further developments.

[0012] The motor vehicle according to the invention is an electrically or partially electrically powered motor vehicle. The motor vehicle has an underfloor battery, wherein the underfloor battery comprises at least one battery module, wherein the battery module comprises a battery module housing and several battery cells arranged in an interior space of the battery module housing, wherein the battery module housing has at least one degassing device for venting gas from the battery module.

[0013] Furthermore, the motor vehicle has an underbody protection plate, the underbody protection plate being arranged in a vertical direction below the underfloor battery, with a degassing space being formed between the underbody protection plate and the battery module housing.

[0014] Furthermore, the vehicle has a connecting component, which is adjacent to the battery module housing. A mounting gap exists between the connecting component and the battery module housing. A sealing arrangement is provided to seal the mounting gap against the degassing chamber, the sealing arrangement comprising a sheet metal strip extending along the mounting gap. The sheet metal strip has a first end section facing the battery module, a second end section facing the connecting component, and a folded section connecting the first and second end sections. The folded section has at least one, preferably exactly one, fold extending into the mounting gap, with a first leg and a second leg bent in the opposite direction.The sheet metal strip is bonded to the battery module housing in a sealing manner, the second end section being connected to the connection component, the sealing arrangement having a sealing element, the sealing element being arranged between the sheet metal strip and the underbody protection plate and acting in a sealing manner with the sheet metal strip and the underbody protection plate.

[0015] The folded section of the sheet metal strip creates a deformation zone that allows the strip to compensate for relative movements between the battery module housing, the underbody protection plate, and the connecting component, particularly along the width of the mounting gap. This reduces the stress on the connection between the aforementioned components and the sheet metal strip, which is especially beneficial for the seal at the point where the strip connects to the other components. This prevents gas leakage from the degassing chamber into the mounting gap, even during relative movements.

[0016] In a particularly preferred embodiment, the sealing element is provided to be elastically deformable.

[0017] The sealing element is preferably a molded seal or profile seal.

[0018] The sealing element can be a FIPG (formed in place gasket), in particular a FIPFG (formed in place foam gasket).

[0019] The sealing element is, in particular, an insert seal.

[0020] The sealing element is preferably a silicone seal.

[0021] It is considered particularly advantageous if the first leg is bonded to the battery module housing in a sealing manner, preferably over its entire surface. In this case, the bond can be less robust in terms of its mechanical stability, especially with regard to shear forces, than with a direct bond between the underbody protection plate and the battery module housing. This is because the deformability of the sheet metal strip due to the fold allows for a particularly low mechanical stress on the bond, thus enabling the use of less mechanically stable bonds or adhesives. This increases the selection of potentially applicable adhesives, as the mechanical stability criterion of the bond is less stringent. This may, if necessary,Adhesives are used that better meet other criteria, such as the chemical or thermal stability of the adhesive, but would not be sufficiently stable without the metal strip. Thus, the metal strip is what makes the use of such adhesives possible in the first place.

[0022] It is considered particularly advantageous if the underbody protection plate is mechanically attached to the connecting component. The mechanical attachment of the underbody protection plate to the connecting component can be achieved, for example, using screws.

[0023] It is considered particularly advantageous if the connecting component is a housing, in which a battery management system is included.

[0024] In a particularly preferred embodiment, the sheet metal strip has a thickness of 0.3 mm to 0.8 mm. Such a thickness has proven particularly advantageous with regard to the formability of the folded section. Furthermore, a sheet metal strip of such thickness can be manufactured particularly well, especially with regard to the necessary bending of the sheet metal strip to form the folded section.

[0025] In a particularly preferred embodiment, the mounting gap is provided to have a gap width of 1 mm to 5 mm.

[0026] It is considered particularly advantageous if the sealing arrangement includes a sealing component, wherein the sealing component comprises the sheet metal strip and the sealing element, and the sealing element is permanently connected to the sheet metal strip. With such a design, the sealing component can be prefabricated or pre-assembled and then assembled as a whole. This reduces cycle times. Furthermore, it prevents errors in the spatial arrangement of the sheet metal strip and the sealing element.

[0027] Particularly in connection with the sealing component, it is considered especially advantageous if the sealing element is injection-molded onto the sheet metal strip.

[0028] In a particularly preferred embodiment, the first end section and the first leg are angled relative to each other such that the first end section and the first leg follow an outer contour of the battery module housing in a lower corner region of the battery module housing. The angle between the first leg and the first end section is preferably 90°.

[0029] In a design where the first end section and the first leg are angled relative to each other, it is considered particularly advantageous, for the sake of a particularly strong bond, if both the first end section and the first leg are bonded to the battery module housing. Such a design allows for a particularly stable connection between the sheet metal strip and the battery module housing.

[0030] In an advantageous further development, it is provided that the second end section has a multitude of through-openings for screwing the second end section to the connecting component.

[0031] It is quite conceivable that the second leg has further fold sections formed perpendicular to the vehicle's vertical direction. Such fold sections are particularly suitable for compensating for relative movements of the components, namely the underbody protection plate, battery module housing, and connection component, to each other in the vehicle's vertical direction.

[0032] The following figures explain the invention in more detail using one exemplary embodiment, without being limited to this embodiment. They show: Fig. 1. A battery system of an electrically or partially electrically powered motor vehicle in a perspective view, Fig. 2 the battery system according to Fig. 1 in a longitudinal section, Fig. 3 a sub-area of Fig. 3 according to the marking III in Fig. 2, Fig. 4 a sub-area of ​​the battery system according to Fig. 1 in a view from below, Fig. 5. The battery system in a sectional view along line AA in Fig. 4, Fig. 6 A sealing component of the battery system in a perspective view.

[0033] In the figures, a vehicle vertical direction is indicated by an arrow Z, a vehicle longitudinal direction is indicated by an arrow Y, and a vehicle longitudinal direction is indicated by an arrow X.

[0034] The Fig. Figure 1 shows a battery system 1 of an electrically or partially electrically powered motor vehicle. The battery system 1 comprises an underfloor battery 10. The underfloor battery 10 has three battery modules 20. Each battery module 20 has a battery module housing 22 and several battery cells 24 arranged in an interior space of the battery module housing 22. The respective battery module housing 22 has a degassing device for each battery cell 24. The degassing devices of the battery module housing 22 are designed as openings. In practice, these openings are closed with rupture discs or valves. These open or rupture in the event of degassing, thus releasing the degassing devices, which are designed as openings, to allow gas to escape from the respective battery module 20.

[0035] The battery system 1 has an underbody protection plate 30, which is arranged in the vehicle's vertical direction Z below the underfloor battery 10. A degassing chamber 50 is formed between the underbody protection plate 30 and the battery module housing 22 of the respective battery module 20. In the area of ​​the respective battery module 20, the degassing chamber 50 is bounded by a bottom surface 23 of the respective battery module housing 22 facing the underbody protection plate 30 and the underbody protection plate 30 spaced apart from it.

[0036] As in particular the Fig. As can be seen in Figure 2, the rear battery module 20 in the longitudinal direction X of the vehicle borders a connection component 80, namely a housing of a battery management system, in the longitudinal direction X of the vehicle. In this area, there is a mounting gap 70 between the battery module housing 22 and the connection component 80, which extends along the transverse direction Y of the vehicle. This mounting gap 70 is shown schematically in the Fig. Figure 5 shows the following. In this case, the gap width B of the mounting gap 70 is approximately 4 mm. This mounting gap 70 must be reliably sealed against the adjacent degassing chamber 50 to prevent gas from escaping from the degassing chamber 50 via the mounting gap 70, as such an escape could endanger people.

[0037] To seal the mounting gap 70 against the degassing chamber 50, a sealing arrangement is provided between the connecting component 80, the battery module housing 22, and the underbody protection plate 30. In this case, the sealing arrangement is formed by a sealing component 60. The sealing component 60 has a sheet metal strip 62 extending along the mounting gap 70, thus in the transverse direction Y of the vehicle. The sheet metal strip 62 has a first end section 64 facing the battery module 20. The sheet metal strip 62 also has a second end section 65 facing the connecting component 80. In the vertical direction Z of the vehicle, the second end section 65 is deeper than the first end section 64.

[0038] The sheet metal strip 62 has a folded section connecting the first end section 64 with the second end section 65, the folded section having exactly one fold 67 extending into the mounting gap 70. The fold 67 has a first leg 68 bent upwards relative to the first end section 64 and a second leg 69 bent downwards by 180° relative to the first leg 68. The first leg 68 and the second leg 69 are bent perpendicularly relative to the first end section 64 and the second end section 65, respectively, run parallel to each other, and lie against each other over their entire surface but loosely.

[0039] The sheet metal strip 62 is sealed to the battery module housing 22 by means of an adhesive bond 90. The adhesive bond 90 extends over the first end section 64 and over the first leg 68, such that the sheet metal strip 62 is fully bonded to the battery module housing 22 in a corner area.

[0040] The second end section 65 is connected to the connecting component 80 via screws 3. For this purpose, the second end section 65 has several through-openings 66.

[0041] The sealing component 60 has a sealing element 61 in the form of an injection-molded silicone seal. The sealing element 61 is injection-molded onto both the first end section 64 and the second end section 65. In the installed state, the sealing element 61 seals against an inner surface of the underbody protection plate 30 facing the battery module 20. To allow for non-destructive removal of the underbody protection plate 30, no material bond, in particular no adhesive bond, is provided between the sealing element 61 and the underbody protection plate 30. This allows the underbody protection plate 30 to be removed without removing the sealing component 60 and without damaging the sealing element 61. Accordingly, replacing the underbody protection plate 30 and any necessary repairs can be carried out with minimal effort.

[0042] As particularly the sectional view of the Fig.As can be seen from Figure 5, the sealing element 61 is positioned closer to the mechanical fastening of the underbody protection plate 30, namely to the screw 3, than the battery module housing 22. This design places the sealing element 61 particularly close to the mechanical fixation of the underbody protection plate 30 to the connecting component 80. In the event of degassing and the associated pressure increase in the degassing chamber 50, which can lead to deformation, in particular bulging, of the underbody protection plate 30, the least relative movement occurs in the area of ​​the screw connection between the underbody protection plate 30 and the connecting component 80. Because the sheet metal strip 62 positions the sealing element 61 particularly close to the screw connection, the sealing of the mounting gap 70 against the degassing chamber 50 is improved during degassing. Reference symbol list 1 battery system 10 Underfloor battery 20 battery modules 22 Battery module housings 23 Underside 30 Underbody protection plate 50 Degassing room 60 Sealing component 61 Sealing element 62 strips of sheet metal 64 first section 65 second section 67 fold 68 first thigh 69 second thigh 70 Mounting gap 80 Connecting component 90 Bonding B Gap width X Vehicle longitudinal direction Y Vehicle transverse direction Z Vehicle lifting direction

Claims

[1] Motor vehicle designed as an electrically or partially electrically powered motor vehicle comprising: - an underfloor battery (10), wherein the underfloor battery (10) comprises at least one battery module (20), the battery module (20) comprising a battery module housing (22) and several battery cells (24) arranged in an interior of the battery module housing (22), the battery module housing (22) comprising at least one degassing device (28) for venting gas from the battery module (20), - an underbody protection plate (30), wherein the underbody protection plate (30) is arranged in a vehicle vertical direction (Z) below the underbody battery (10), wherein a degassing space (50) is formed between the underbody protection plate (30) and the battery module housing (22), - a connecting component (80), wherein the connecting component (80) is adjacent to the battery module housing (22), characterized bythat a mounting gap (70) exists between the connecting component (80) and the battery module housing (22), wherein a sealing arrangement is provided for sealing the mounting gap (70) against the degassing chamber (50), wherein the sealing arrangement comprises a sheet metal strip (62) extending along the mounting gap (70), wherein the sheet metal strip (62) has a first end section (64) facing the battery module (20), a second end section (65) facing the connecting component (80), and a folded section connecting the first end section (64) with the second end section (65), wherein the folded section has a fold (67) extending into the mounting gap (70) with a first leg (68) and with a second leg (69) bent in the opposite direction, wherein the sheet metal strip (62) is sealed to the battery module housing (22), wherein the second end section (65) is connected to the The connecting component (80) is connected,wherein the sealing arrangement comprises a sealing element (61), wherein the sealing element (61) is arranged between the sheet metal strip (62) and the underbody protection plate (30) and interacts sealingly with the sheet metal strip (62) and the underbody protection plate (30). [2] Motor vehicle according to claim 1, wherein the first leg (68) is sealed to the battery module housing (22), preferably fully bonded. [3] Motor vehicle according to claim 1 or 2, wherein the underbody protection plate (30) is mechanically attached to the connecting component (80). [4] Motor vehicle according to one of claims 1 to 3, wherein the connecting component (80) is a housing, wherein a battery management system is included in the housing. [5] Motor vehicle according to one of claims 1 to 4, wherein the sheet metal strip (62) has a thickness of 0.3 mm to 0.8 mm. [6] Motor vehicle according to any one of claims 1 to 5, wherein the mounting gap (70) has a gap width (B) of 1 mm to 5 mm. [7] Motor vehicle according to one of claims 1 to 6, wherein the sealing arrangement comprises a sealing component (60), wherein the sealing component (60) comprises the sheet metal strip (62) and the sealing element (61), wherein the sealing element (61) is inseparably connected to the sheet metal strip (62). [8] Motor vehicle according to one of claims 1 to 7, wherein the sealing element (61) is injection-molded onto the sheet metal strip (62). [9] Motor vehicle according to one of claims 1 to 8, wherein the first end section (64) and the first leg (68) are angled to each other such that the first end section (64) and the first leg (68) follow an outer contour of the battery module housing (22) in a lower corner region of the battery module housing (22). [10] Motor vehicle according to one of claims 1 to 9, wherein the second end section (65) has a plurality of through-openings (66) for screwing the second end section (65) to the connecting component (80).

Images