Battery housing, in particular underfloor housing for trains

Abstract

The invention relates to a battery housing, in particular an underfloor housing for trains, comprising a main part (2), which is open on one side, for receiving electrically interconnected battery cells and a cover (3), which closes the open side of the main part (2). The battery housing is characterized in that the cover (3) is equipped, on the main part side, with a thermal insulating element (4) which, in the closed position, protrudes at least partly into a volume space (5) provided by the main part (2), a gap (8) being formed in an overlapping region (6) between an edge (7), provided by the main part (2), and the insulating element (4), and the edge (7) and / or the insulating element (4) having a fire protection element (9) made of a material which swells into the gap (8) under the effect of heat.

Description

[0001] Battery housings, especially underfloor housings for trains

[0002] The invention relates to an accumulator housing, in particular an underfloor housing especially for trains, with a base body open on one side for receiving electrically interconnected accumulator cells and a lid closing the open side of the base body.

[0003] Accumulator housings in general, and specifically in their design as underfloor housings for trains, are well known, so a separate printed reference is unnecessary. Therefore, reference is made only by way of example to EP 3 686 959 A1 and EP 3460 870 A1.

[0004] EP 3 686 959 A1 relates to a housing for batteries. This housing consists of a base body open on one side and a lid that closes the open side of the base body. One or more batteries are arranged within a volume space provided by the base body. An insulating lining is arranged on the inside of the lid, which, when the lid is closed, rests against an edge of a leg of the base body facing the lid.

[0005] EP 3 460 870 A1 discloses a housing for one or more batteries. The housing has a base body open on one side and a lid assembly. The lid assembly serves to close the base body, which is open on one side. It consists of a removable lid section on one side and a powder tray located underneath it on the other. When the base body of the housing is closed by means of the lid assembly, the powder tray of the lid assembly extends into a volume space provided by the base body. The powder tray contains a powder which decomposes at a certain temperature, e.g., approximately 100°C to 150°C, releasing one or more inert gases. The powder is activated when a battery located in the base body of the housing releases gas due to overheating, and this gas penetrates the powder tray through openings in the powder tray.

[0006] A typical battery housing consists of a base body. This base body typically has a bottom plate and side walls. The base body is open on the side opposite the bottom plate. The base body provides a volumetric space. In its intended use, this space houses battery cells that are electrically connected. Typically, several battery cells are combined to form a battery module, with the base body accommodating several battery modules arranged side by side in the final assembly. Battery cells are inserted into the base body through the open side. The battery housing is equipped with a lid to close this open side.In its fully assembled state, it is placed on the base body and connected to it, thus completely enclosing and encapsulating the accumulator cells within the accumulator housing.

[0007] The base body and the lid closing the base body are preferably detachably connected in the fully assembled state, which allows maintenance and repair work to be carried out on the battery cells housed in the battery casing. In particular, it allows defective battery cells or modules to be replaced if necessary.

[0008] In its configuration as an underfloor housing for trains, the battery housing, under normal operating conditions, is guided from below against the underbody of a train car. The battery housing can either be directly connected to the underbody or a suitable support device is provided to fix it in position. In either case, the cover of the battery housing rests against the underbody of the car, thus creating a thermal connection between the car underbody and the battery housing.

[0009] Lithium-ion cells are typically used as battery cells, particularly in connection with the power and / or voltage supply of a train. These battery cells can serve as both a primary and a secondary power and / or voltage supply for the train.

[0010] Although existing battery housings have proven their worth in everyday practical use, there is room for improvement. Further development is being pursued, particularly with a view to further improving operational reliability.

[0011] Based on the above description, the invention aims to further develop a battery housing of the type mentioned above in such a way that increased operational safety is achieved while simultaneously simplifying assembly.

[0012] To solve this problem, the invention proposes an accumulator housing of the type mentioned above, which is characterized in that the cover is equipped on the base body side with a thermal insulating body which, in the closed position, projects at least partially into a volume space provided by the base body, wherein a gap is formed in an overlap area between an edge provided by the base body and the insulating body, wherein the edge and / or the insulating body carry a fire protection element made of a material that swells under the influence of heat up into the gap.

[0013] The lid of the accumulator housing designed according to the invention is equipped with a thermal insulating element. The lid carries the insulating element on the base body side, that is, on its inner side facing the base body in the closed position.

[0014] The thermal insulation acts as a thermal barrier in the event of a cell fire. This is particularly advantageous when the battery housing is used as an underfloor housing for trains, as it prevents unwanted heat transfer from the battery housing into the train's underbody, which is thermally coupled to the battery housing. This creates an overall battery system that ensures that, in the event of a cell fire, no heat can spread to the train, especially not to a passenger compartment occupied by people.

[0015] When the battery housing is closed, the insulating body on the lid protrudes at least partially into a volume space provided by the base body. This design provides the synergistic effect of an assembly aid, as the insulating body serves as a centering element when the lid is placed on the base body. This ensures that the lid is correctly positioned on the base body.

[0016] The insulating body and the open side provided by the base body can additionally be designed with position coding, in particular geometrically, so that incorrect positioning of the cover on the base body is structurally excluded.

[0017] According to the invention, it is further provided that a gap is formed in an overlap area between an edge provided by the base body and the insulating body. This gap is preferably designed as a circumferential annular space. It serves to compensate for manufacturing tolerances of the base body, cover, and / or insulating body, so that the cover can always be arranged correctly and securely on the base body.

[0018] To ensure fire safety despite the annular space provided for simplified assembly, a further feature of the invention provides that the edge and / or the insulating body bear a fire protection element made of a material that expands into the gap when exposed to heat. Thus, if a fire occurs inside the battery housing, the fire protection element provided for this purpose expands into the gap between the edge and the insulating body. In the event of a fire, a thermal seal of the gap is therefore created, so that, in combination with the insulating body, a completely closed fire barrier is formed on the cover side. The battery housing according to the invention thus advantageously fulfills the fire protection class required by the standard, according to which fire spread to a passenger compartment of a train must not occur.

[0019] The design according to the invention offers two synergistic advantages. The insulating body provided on the lid side serves as a centering element and thus as an assembly aid. The insulating body acts as a centering aid insofar as, in the closed position, it projects into a volume space provided by the base body, which helps prevent incorrect connection between the lid and the base body. To compensate for any manufacturing tolerances, an annular space is provided between the insulating body and the corresponding edge of the base body, which remains even in the closed position. For complete thermal sealing in the event of a fire, this annular space must be thermally sealed. Therefore, according to the invention, the edge of the base body and / or the insulating body are provided with a corresponding fire protection element, namely one made of a material that expands into the gap when exposed to heat.In this context, "under the influence of heat" means such a heat input into the fire protection element as typically occurs only in the event of a fire, i.e., a heat input at a temperature of, for example, above 50. s C, above 100°C or above 200°C. Heat input, such as that which can occur as a result of high outside temperatures, especially in summer, is not meant by the invention.

[0020] The thermal barrier provided by the inventive design is comprised of two parts: an insulating body and a fire protection element. The fire protection element is activated only in the event of a fire. In combination, the insulating body and the activated fire protection element provide full-surface thermal insulation of the cover in the event of a fire. This ensures that, in accordance with standards, no excessive heat can enter the underbody above the cover, particularly a passenger compartment of a train, via the cover.

[0021] According to a further feature of the invention, the insulating body has a shell with a base plate and a circumferential side wall arranged on the base plate, the open side of which faces the inner surface of the lid on the base body side with the base plate opposite the base plate.

[0022] According to this alternative inventive step, the insulating body has a shell. In its fully assembled state, this shell doubles the lid of the accumulator housing. The shell has a base plate and a circumferential side wall attached to the base plate. In its fully assembled state, the shell's open side, opposite the base plate, faces the lid. This results in a volume space provided by the shell, which is bounded on the one hand by the base plate of the shell and the lid, and on the other hand by the circumferential side wall. The detailed design of the shell is otherwise not essential. The only essential aspect of the invention is that an insulating body is provided on the base side of the lid.The preferably provided shell serves as a structure designed to provide thermal insulation, particularly when configured as a support for a fire-resistant device. The base plate and side walls can be perforated, ribbed, or otherwise designed. According to a further feature of the invention, the volume provided by the shell is entirely filled with air. This results in a particularly cost-effective and simple construction.

[0023] Alternatively, according to a further feature of the invention, a heat-insulating insulating material can be arranged within a volume space provided by the shell. Such insulating material could, for example, be insulating wool. This improves the thermal insulation properties of the insulating body compared to simply filling the volume space on the shell side with air.

[0024] According to a further feature of the invention, the side wall of the bowl is arranged with its end edge facing the lid on the inner surface of the lid. The lid and bowl can therefore be formed as a single piece, which also simplifies manufacturing. The lid can be welded or bonded to the bowl, for example, along the contact area between the bowl side wall and the inner surface of the lid. This results in a completely encapsulated design for the volume space provided by the bowl.

[0025] In this context, it is preferred that the inner surface of the lid and the base plate of the tray run largely parallel to each other. This provides a volume space that is essentially cuboid in shape. Alternatively, however, it is also possible for the side walls of the tray to be at an angle to the base plate of the tray and / or for the base plate to run at an angle to the inside of the lid. Such an angled configuration may arise particularly depending on the volume space provided by the base body for accommodating battery cells, especially to avoid collisions during assembly.

[0026] According to an alternative embodiment, the tray is arranged on the lid, leaving a gap between the side wall and the inside of the lid.

[0027] A direct connection between the shell's sidewall and the lid has the disadvantage of creating a thermal connection, thus forming a thermal bridge. To avoid this, the shell's sidewall does not extend to the lid, meaning it is not thermally connected to it. This achieves thermal decoupling between the shell's sidewall and the lid, preventing unwanted heat transfer from the sidewall to the lid. The gap between the shell's sidewall and the inside of the lid further reduces heat transfer into the accumulator housing's lid in the event of a fire.

[0028] The tray is preferably attached to the lid using stiffening ribs that are already provided on the lid side and are located on the inside of the lid.

[0029] To ensure the lid is stable against mechanical forces, it features internally formed reinforcing ribs. These preferably serve as attachment points for the shell of the thermal insulation body. While this does create a thermal bridge to the lid, it is significantly smaller than with a full-rim connection between the shell's side wall and the lid.

[0030] Alternatively or additionally, the shell can be designed to be supported against the base body and / or the accumulator cells housed within the base body. This can further reduce the thermal connection between the shell and the lid.

[0031] According to a further feature of the invention, it is provided that the

[0032] The fire protection element is located on the outside of the shell, on its side wall.

[0033] According to this preferred embodiment, the insulating body also carries the

[0034] Fire protection element. The fire protection element is located on the outside of the shell, specifically on the outer side of the shell's side wall.

[0035] According to this embodiment, the base-side edge is preferably designed to run essentially parallel to the side wall of the shell. The base-side edge and the side wall of the shell extend in the vertical direction of the accumulator housing, that is, essentially orthogonal to the base plate of the shell. Thus, when the lid is closed, the insulating body of the lid and the interacting edge of the base interlock concentrically, leaving an annular gap between the base-side edge and the side wall provided by the shell. In the event of a fire, the fire protection element supported by the side wall of the shell expands and thus closes the annular gap between the base and the lid. As previously described, this creates a complete thermal seal.

[0036] According to a further feature of the invention, the fire protection element is provided for to be bonded and / or mechanically connected to the side wall. Screws, rivets, pins, and / or similar bolts may be used for mechanical connection. Bonding is preferred for reasons of simplified manufacturing. An additional mechanical connection may be provided, particularly for safety reasons, especially to ensure that the fire protection element remains securely fixed in position relative to the side wall of the shell even if the adhesive bond fails in the event of a fire.

[0037] According to an alternative embodiment of the invention, the insulating body does not have a shell, but rather a protective plate spaced apart from the inner surface of the lid on the base body side. The protective plate is essentially parallel to the inner surface of the lid. In this embodiment, a shell-shaped design with a circumferential side wall is omitted. The protective plate is spaced apart from the inner surface of the lid, and the space between can be filled either exclusively with air or with an insulating material. Preferably, such a protective plate is arranged on the lid with an intermediate lid stiffener. In particular, ribs can be provided as the lid stiffener, resulting in a sandwich-like structure.

[0038] As an alternative to placing insulating material between the protective plate and the cover, the protective plate can be equipped on the cover side with a fire retardant made of a material that expands under the influence of heat. According to this design variant, not only is a fire protection element made of such a material used, but also a fire retardant made of this material, with the fire retardant being positioned between the cover and the protective plate. The space between the cover and the protective plate is therefore only closed in the event of a fire, namely when the material that expands under the influence of heat actually expands and fills the space between the cover and the protective plate.

[0039] According to a further feature of the invention, the base body has an internal support device arranged on a side wall of the base body, the support device providing the edge of the base body. According to this embodiment, a support device is provided that provides the edge or another edge of the base body. This edge interacts with the fire protection element provided according to the invention, whether the fire protection element is arranged on the edge itself or on the insulating body interacting with it.

[0040] The support structure is preferably designed as a wall extension of the base body, located above the accumulator cells housed within the base body. This wall extension serves as an additional heat shield. The wall extension can also be equipped with a material that expands when heated. In this case, the housing-side structure is a sandwich construction consisting of a housing wall, a material that expands in the event of a fire, and a second wall that acts as a support wall for the expanding material. According to this particular embodiment, the mounting gap between the support structure on the base body and the cover can also be designed essentially transversely to the vertical direction of the accumulator housing. Therefore, in this case, a gap dimension running essentially parallel to the protective plate or the base plate of the shell is also possible.The decisive factor is solely that the fire protection element provided according to the invention is positioned either on the support structure or on the shell or the protective plate in such a way that, in the event of a fire, it swells up, resulting in a gap closure, so that a full-surface thermal barrier is formed in the manner already described above.

[0041] According to a further feature of the invention, the fire protection element and / or the fire protection agent are designed as a film. Simple manufacturing is permitted, particularly in the case of a self-adhesive film.

[0042] According to a further feature of the invention, the base body is provided with a fluid seal that interacts with the lid. This functionally divides the body into two parts: a thermal seal and a fluid-tight seal. The thermal seal is achieved, as previously described, by the insulating body in combination with the fire protection element, while the fluid-tight seal is provided by the separately designed fluid seal located between the base body and the lid. Preferably, the fluid seal is supported by an edge on the base body, upon which the lid rests in the closed position, with the fluid seal positioned between the lid and the lid.

[0043] Further features and advantages of the invention will become apparent from the following description with reference to the figures. These show

[0044] Fig. 1 shows a schematic sectional view of a partial section of an accumulator housing according to a first embodiment of the invention;

[0045] Fig. 2 shows a schematic sectional view of a partial section of an accumulator housing according to a second embodiment of the invention and

[0046] Fig. 3 shows a schematic perspective view of an accumulator housing according to the invention.

[0047] Fig. 1 shows a schematic sectional view of a partial section of an accumulator housing 1 according to the invention, specifically in the form of an underfloor housing for rail vehicles, in particular trains, and / or land vehicles, in particular road vehicles.

[0048] The accumulator housing 1 has, in a manner known per se, a base body 2 open on one side for receiving electrically interconnected accumulator cells, which are not shown in Fig. 1 for clarity. The accumulator housing 1 also has a cover 3 which, in its intended use, serves to close the open side of the base body 2. Fig. 1 shows this closed position.

[0049] The cover 3 is equipped with a thermal insulation element 4 on the base body side. In the closed position, this element projects at least partially into a volume space 5 provided by the base body 2. This volume space 5 also serves to accommodate the accumulator cells, which are not shown in detail in Fig. 1. In the closed position shown in Fig. 1, an overlap area 6 is formed between an edge 7 provided by the base body 2 on the one hand and the insulation element 4 on the other. This overlap area 6 provides a gap space 8.

[0050] The gap 8 serves to compensate for any manufacturing tolerances of the base body 2, cover 3 and / or insulating body 4 during assembly. The insulating body 4 also acts as a centering aid for the correct and precise positioning of the cover 3 relative to the base body 2.

[0051] According to the illustrated embodiment, the insulating body 4 carries a fire protection element 9 made of a material that expands under the influence of heat, extending into the gap 8. In the event of a fire, both the insulating body 4 and the fire protection element 9, which closes the mounting gap, i.e., the gap 8, thus provide thermal insulation. The cover 3 is therefore fully thermally insulating in the event of a fire, which helps to prevent a cell fire from spreading to the surrounding environment. This is particularly advantageous when the accumulator housing 1 according to the invention is used as an underfloor housing for a train.

[0052] According to the illustrated embodiment, the insulating body 4 has a shell 10. This shell 10 has a base plate 11 with a circumferential side wall 12 arranged on the base plate 11. The open side of the shell 10 opposite the base plate 11 faces the inner surface 18 of the cover 3 on the base body side. In this respect, the cover 3 is doubled, forming a volume space 14.

[0053] According to the embodiment shown in Fig. 1, the volume space 14 provided by the shell 10 is filled with a heat-insulating insulating material 15. The shell 10 thus accommodates the insulating material 15, which can be, for example, insulating wool. According to the alternative embodiment shown in Fig. 2, the volume space 11 provided by the shell 10 is air-filled, and the shell 10 carries a fire-resistant material 19 on its base plate side, as will be discussed further below.

[0054] As Figures 1 and 2 can be seen, the end edge 16 of the shell side wall 12 on the lid side does not rest against the inner surface 18 of the lid. Instead, the shell 10 is arranged on the lid 3, leaving a gap 17 between the side wall 12 and the inner surface 18 of the lid. This provides thermal decoupling between the shell 10 and the lid 3, at least with respect to the side wall 12 of the shell 10.

[0055] The lid 3 has 18 stiffening ribs 21 on its inner surface for stiffening purposes. These provide fixing points for the positionally secure arrangement of the tray 10 on the lid 3, which allows the previously described design of the gap distance 17 between the inner surface 18 of the lid and the front edge 16 of the side wall 12.

[0056] The fire protection element 9 according to the embodiments shown in Figures 1 and 2 is arranged on the outside of the shell 10 on its side wall 12, with a first section 13. The fire protection element 9 has a second section 23 that extends into a region of the base plate 11 of the shell 10. The fire protection element 9 consists of a material that expands under the influence of heat, so that in the event of a fire, the fire protection element 9 extends at least into and fills the gap 8 between the edge 7 of the base body 2 and the insulating body 4. Figures 1 and 2 show the fire protection element 9 in its non-expanded state, i.e., before heat-induced activation.

[0057] According to the embodiment shown in Fig. 2, unlike the embodiment shown in Fig. 1, no insulating material 15 is used within the shell 10. Instead, a fire protection agent 19 is provided, which is formed on the base plate side of the shell 10. The fire protection agent 19, like the fire protection element 9, consists of a material that expands under the influence of heat.

[0058] Both the fire protection element 9 and the fire protection material 19 are preferably designed as self-adhesive films, which simplifies installation. In addition to an adhesive bond between the fire protection element 9 or fire protection material 19 and the side wall 12 or base plate 11, a mechanical connection between the fire protection element 9 or fire protection material 19 and the shell 10 can also be provided.

[0059] For a fluid seal in the closed position of the lid 3, the base body 2 carries a fluid seal 20 that interacts with the lid 3. In the illustrated embodiment, this is placed on the edge 7 provided by the base body 2.

[0060] When the lid 3 is closed, electrical contact is made between the battery cells provided by the accumulator housing 1 via externally accessible battery terminals 22, as can also be seen in both Figures 1 and 2.

[0061] Finally, Fig. 3 shows an overall view of an exemplary accumulator housing 1. In the illustrated embodiment, this provides a total of three compartments 24, each serving to accommodate a plurality of accumulator modules 25. Each accumulator module 25 has a plurality of electrically interconnected accumulator cells.

[0062] In the illustrated embodiment, three covers 3 are used to close the open side of the accumulator housing 1, one cover 3 for each compartment 24.

[0063] As shown in Fig. 3, only one of these covers 3 is shown, namely for the compartment 24 on the left with reference to the plane of the drawing in Fig. 3.

[0064] Reference sign

[0065] 1 accumulator housing

[0066] 2 basic shapes

[0067] 3 lids

[0068] 4 insulating bodies

[0069] 5 volume space

[0070] 6 Overlap area

[0071] 7 Edge

[0072] 8 gap space

[0073] 9 fire protection element

[0074] 10 bowls

[0075] 11 Base plate

[0076] 12 side wall

[0077] 13 first section

[0078] 14 Volume space

[0079] 15 Insulation material

[0080] 16 Front edge

[0081] 17 gap spacing

[0082] 18 Inside of lid (inner surface of lid)

[0083] 19 fire protection products

[0084] 20 Fluid seal

[0085] 21 Stiffening rib

[0086] 22 battery terminal

[0087] 23 second section

[0088] 24 compartments

[0089] 25 Accumulator module

Claims

Patent claims 1. Accumulator housing, in particular underfloor housing for trains, with a base body (2) open on one side for receiving electrically interconnected accumulator cells and a cover (3) closing the open side of the base body (2), characterized in that the cover (3) is equipped on the base body side with a thermal insulating body (4) which, in the closed position, projects at least partially into a volume space (5) provided by the base body (2), wherein a gap space (8) is formed in an overlap area (6) between an edge edge (7) provided by the base body (2) and the insulating body (4), wherein the edge edge (7) and / or the insulating body (4) carry a fire protection element (9) made of a material that expands under the influence of heat into the gap space (8).

2. Accumulator housing according to claim 1, characterized in that the insulating body (4) has a shell (10) with a base plate (11) and a circumferential side wall (12) arranged on the base plate (11), the open side of which is designed to face the inner surface (18) of the lid (3) on the base body side opposite the base plate (11).

3. Accumulator housing according to claim 2, characterized in that a volume space (14) provided by the shell (10) is exclusively filled with air.

4. Accumulator housing according to claim 2, characterized in that a heat-insulating insulating material (15) is arranged within a volume space (14) provided by the shell (10).

5. Accumulator housing according to one of the preceding claims 2, 3 or 4, characterized in that the side wall (12) of the shell (10) is arranged with its end edge (16) facing the lid on the inside (18) of the lid (3) facing the shell (10).

6. Accumulator housing according to one of the preceding claims 2, 3 or 4, characterized in that the shell (10) is arranged on the lid (3) leaving a gap (17) between the side wall (12) and the inside of the lid (18).

7. Accumulator housing according to one of the preceding claims 2 to 6, characterized in that the shell (10) is supported against the base body (2) and / or accumulator cells received by the base body (2).

8. Accumulator housing according to one of the preceding claims 2 to 7, characterized in that the fire protection element (9) is arranged on the outside of the shell (10) on its side wall (12).

9. Accumulator housing according to claim 8, characterized in that the fire protection element (9) is bonded and / or mechanically connected to the side wall (12).

10. Accumulator housing according to one of the preceding claims, characterized in that the insulating body (4) has a protective plate spaced apart from the inner surface (18) of the cover (3) on the base body side.

11. Accumulator housing according to claim 10, characterized in that the protective plate is equipped on the lid side with a fire protection agent (19) made of a material that swells under the influence of heat.

12. Accumulator housing according to one of the preceding claims, characterized in that the base body (2) has a support device on the inside which is arranged on a side wall of the base body (2), wherein the support device provides the edge of the base body.

13. Accumulator housing according to one of the preceding claims, characterized in that the fire protection element (9) and / or the fire protection agent (19) are designed as a film.

14. Accumulator housing according to one of the preceding claims, wherein characterized in that the base body (2) carries a fluid seal (20) which interacts with the cover (3).

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