Cooling profile for a battery module with at least one battery unit

Abstract

Cooling profile (10) for a battery module with at least one battery unit, with a metallic housing (11) which has at least two opposing longitudinal walls (12) extending in the longitudinal direction of the housing (11) which are in their initial position (12.1) when no external force (30) is applied to the longitudinal walls (12), characterized by that at least one spring element (20) is provided in the housing (11), which is arranged between the two longitudinal walls (12) when it is in its initial form (20.1), wherein the longitudinal walls (12) of the housing (11) have such a small wall thickness (13) that they can be moved towards each other by external force (30) and can be elastically deformed and thereby assume their acted position (12.2). and that when force (30) is applied from the outside, by bringing at least one of the longitudinal walls (12) into its actuated position (12.2), at least one of the spring elements (20) is deformed against its spring force between the two longitudinal walls (12) and thus assumes a compressed shape (20.2), whereby when the force (30) ceases to apply, the spring element (20) can be returned to its original shape (20.1) and the longitudinal walls (12) can be returned to their original position (12.1).

Description

[0001] The invention relates to a cooling profile for a battery module of the type mentioned in the preamble of claim 1. Battery modules equipped with individual battery cells are used in electric and hybrid vehicles. These modules must be cooled regularly, as they heat up, particularly during charging and discharging, and excessively high temperatures negatively impact the service life of the battery cells. It is therefore important to place a cooling device, such as a cooling profile, as close as possible to the battery module to enable good heat transfer.

[0002] However, it should be noted that battery modules expand and contract, thus changing their external dimensions. These movements occur when the batteries are charged and discharged, but battery modules can also expand due to age.

[0003] EP 3 553 876 B1 describes a refrigerant distributor for battery modules in electric vehicles. This distributor includes, among other things, a base plate with several refrigerant channels through which a refrigerant can be conducted. If the external dimensions of the battery cells change, the contact between the battery cell and the base plate can deteriorate, resulting in a reduction in heat transfer and thus in the cooling effect.

[0004] EP 3 333 966 A1 also describes a cooling plate for battery modules in electric vehicles. This plate, too, comprises several chambers through which a coolant can flow to cool the batteries. The issue of changing the size of battery modules is also not considered, so that even in this case, if the size of the battery modules changes, good contact and thus good heat transfer between the battery module and the cooling plate is not guaranteed over the lifetime of the battery modules.

[0005] Finally, DE 10 2017 125 004 A1 also describes a cooling profile for a battery module. This also includes several hollow chambers through which a coolant can flow. However, this also does not take into account the changes in the external dimensions of the battery modules over their lifetime.

[0006] The object of the invention is therefore to develop a cooling profile that takes into account the fact that battery modules change their external dimensions over their lifetime, while still enabling good and secure contact and thus effective heat transfer between the cooling profile and the battery module. Furthermore, the cooling profile should be simple and cost-effective to manufacture. These objects are achieved by the characterizing features in claim 1, which are of particular importance as follows.

[0007] At least one spring element is provided inside the housing and is arranged between the two longitudinal walls of the housing. If no external force is exerted on the longitudinal walls - for example by an expanding battery module - the longitudinal walls are in their initial position and the spring element in its initial shape. The longitudinal walls of the housing are designed with such a thin wall thickness that they move towards one another when subjected to an external force, such as can occur due to the expansion of the external dimensions of a battery module, and in doing so they deform elastically and reach their loaded position. It should be noted that this is not a precisely defined individual position, but that the exact "loaded position" is determined by the strength of the applied force, for example by the exact expansion of the battery module.The transfer to the loaded position can refer to one or both of the longitudinal walls. One of the longitudinal walls can move toward the other and reach its loaded position while the other remains in its initial position, or both longitudinal walls can move toward each other and reach their loaded positions. In doing so, at least one of the spring elements is brought into its compressed form against its spring force. This compressed form is also not rigidly defined, since the spring element can be compressed more or less depending on the magnitude of the force applied and thus depending on the loaded position of the longitudinal wall.

[0008] When the force acting on the longitudinal wall decreases or even stops completely—for example, because the battery module has returned to its original size—the spring element can be returned to its original shape and the longitudinal wall can be returned to its original position. The spring element's spring force supports the return of the longitudinal wall to its original position.

[0009] This process can be repeated frequently, so that even frequent changes in the external dimensions of the battery module do not have a negative impact on the cooling properties due to the compressibility of the cooling profile. Because the cooling profile essentially moves with changes in the external dimensions of the battery module, it can always be in close contact with the battery module, ensuring maximum cooling contact with the battery module. This enables a long service life for the battery module.

[0010] The housing wall is preferably made of sheet metal. This is inexpensive to manufacture, can be available in the required wall thickness, and is easy to process. Particularly preferred is the sheet metal being formed into a housing by roll forming. The then open ends can be joined by welding, for example, by laser welding or HF welding. The spring elements can then already be attached to the raw material, for example, by overmolding an elastic plastic material. If the following manufacturing steps are taken, the housing can be manufactured simply and cost-effectively: - Unwinding the sheet from the coil - Applying the spring elements to the designated locations - Roll forming of the sheet metal into a housing, if necessary by inserting one or more webs - Welding the two outer edges to close the housing lengthwise.

[0011] The transverse ends of the housing can be closed with a manifold, a closure, or something similar. This also allows the cooling medium to be fed into the cooling profile or removed again for cooling. Aluminum, an aluminum alloy, or even steel can be used as sheet material. These can be easily formed into the desired shape by roll forming.

[0012] In a particularly preferred embodiment, one or both longitudinal walls have one or more webs that can protrude into the interior of the housing. These webs can have several functions. Firstly, they serve to stabilize the housing of the cooling profile. However, they also increase the surface area if, for example, a cooling medium is provided inside the housing. Finally, they serve as a stop when one longitudinal wall of the housing is moved towards the opposite longitudinal wall by the application of force. This ensures a maximum loaded position of the longitudinal walls and also a maximum compressed shape of the spring elements. Damage to the cooling profile can thus be avoided.If a force is applied to a longitudinal wall of the cooling profile, for example, due to the expansion of a battery module, this longitudinal wall moves toward the opposite longitudinal wall of the same cooling profile, assumes its loaded position, and compresses one or more spring elements, thereby returning them to their compressed state. If the force is large enough, the longitudinal wall is moved until at least one web of this longitudinal wall touches the opposite longitudinal wall, or until at least one web of the opposite longitudinal wall touches this longitudinal wall. The webs thus serve as stops for the maximum movement and the maximum loaded position of the longitudinal walls.

[0013] The spring elements can be arranged inside the housing in such a way that they touch both longitudinal walls of the housing, even in their initial position. This allows the spring force of the spring element to act directly upon any force acting on the housing, and when the force is released, it can help return the longitudinal wall to its original position. It is also advantageous if the spring elements run along the longitudinal direction of the housing and are fixed inside the housing. This prevents the spring elements from slipping.

[0014] The spring elements can be made of a plastic, particularly an elastomer or plastic foam, which exhibits corresponding elastic and spring properties. It may also be intended to manufacture the spring elements from spring steel. Overall, a cooling profile can also contain a variety of spring elements. The choice of material depends on the specific application. A plastic material can be injection-molded onto the inside of a longitudinal wall.

[0015] Preferably, the cooling profile is designed so that a spring element and a web are provided alternately along the transverse direction of the housing. Particularly preferably, the distances between the spring elements and the webs are also identical on large sections, ensuring the most even distribution possible.

[0016] To improve heat transfer between the battery module and the cooling profile, a thermally conductive medium can be provided on at least one of the outer sides of the cooling profile. This can be, for example, a thermal paste, a thermal pad, or something similar. Whether and, if so, which thermally conductive medium is used depends on the specific application.

[0017] To better dissipate the heat emitted by the battery module, a cooling medium can flow through the cooling profile. This can be water, a mixture of water and glycol, or other single-phase or multi-phase refrigerants. After absorbing the heat from the battery module, the cooling medium can then be cooled down again in a conventional coolant circuit and then fed back into the cooling profile.

[0018] Further advantages and embodiments are set forth in the dependent claims, the following description, and the drawings. The figures illustrate the invention in an exemplary embodiment. They show: Fig. 1: a cooling profile according to the invention, with longitudinal walls in initial position in section along its transverse direction, Fig. 2: the cooling profile from Fig. 1, under force with longitudinal walls in loaded position, Fig. 3: an excerpt from Fig. 1, Fig. 4: an enlarged section of Fig. 3, Fig. 5: a sheet with spring elements.

[0019] In Fig. Figure 1 shows a cooling profile 10 with a housing 11, sectioned transversely. Several spring elements 20 are visible, arranged alternately with webs 21. The webs 21 protrude alternately from one and the other longitudinal wall 12 into the interior 15 of the housing 11. The wall of the housing 11 has the same wind force 13 throughout.

[0020] In Fig. 1, the cooling profile 10 is not subjected to any force. The longitudinal walls 12 are in their initial positions 12.1 and the spring elements 20 are in their initial shapes 20.1. Fig. Figure 2 shows the cooling profile 10 under the action of force 30. The force 30 acts on both longitudinal walls 12. This causes the longitudinal walls 12 to move toward each other and are in their loaded position 12.2. The spring elements 20 are pressed together and are in their compressed form 20.2. The webs 21 in the central region of the cooling profile 10 serve as stops for the longitudinal walls 12, which cannot be deformed further. It can be seen that not all spring elements 20 have the same compressed form 20.2. The loaded position 12.2 of the longitudinal walls 12 also varies depending on the location and intensity of the force 30.

[0021] If the force 30 stops, the cooling profile 10 resumes the Fig. 1, and the longitudinal walls 12 are returned to their initial positions 12.1 and the spring elements 20 are returned to their initial shapes 20.1. This process is reversible.

[0022] The Fig. 3 and Fig. 4 shows the structure of the cooling profile 10 in more detail. It can be seen that in this exemplary embodiment, the webs 21 were also formed by roll forming the sheet metal material from which the housing 11 is made. They are formed integrally with the housing 11. Of course, it is also possible to connect the webs 21 to the housing 11 in a different way. Fig. 4 also shows the weld seam 14 with which the two ends of the sheet metal material from which the housing 11 is made were joined together to close the housing 11 longitudinally. The longitudinal direction of the housing 11 extends into and out of the image plane, while the transverse direction runs between left and right in the illustrated figures.

[0023] Fig.Figure 5 finally shows the starting material from which a housing 11 according to the invention can be produced. It shows a sheet metal material which, after roll forming, forms, for example, a longitudinal wall 12 of the housing 11. The spring elements 20 are already applied to the material at the desired locations and secured there. This prevents the spring elements 20 from slipping. The material is then bent and deformed by roll forming to create the housing 11 shown in the previous figure, including the webs 21. The ends of the sheet metal are welded together, forming the weld seam 14 to close the housing 11 in the longitudinal direction.

[0024] Finally, it should be noted that the exemplary embodiments presented here merely represent exemplary implementations of the invention. This is not limited to them. Rather, modifications and variations are still possible. Of course, it is also possible to allow a heated medium to flow through the cooling profile if the temperature management of the battery module provides for this, for example, when the ambient temperature of the vehicle is significantly below zero. The spring elements do not have to have a square cross-section. If, for example, they were sprayed onto the housing, they can also have a roughly hill-shaped cross-section. Any other shapes are also conceivable and encompassed by the inventive concept. The cooling profile can also have several chambers and be shaped differently than in the figures shown. List of reference symbols: 10 Cooling profile 11 housings 12 Longitudinal wall 12.1 Starting position of 12 12.2 loaded position of 12 13 Wall thickness of 12 14 Weld seam 15 Interior of 11 16 outside of 12 20 spring element 20.1 Initial form of 20 20.2 Compressed form of 20 21 jetty 30 Force application QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] EP 3 553 876 B1

[0003] EP 3 333 966 A1

[0004] DE 10 2017 125 004 A1

[0005]

Claims

[1] Cooling profile (10) for a battery module with at least one battery unit, with a metallic housing (11) which has at least two opposite longitudinal walls (12) extending in the longitudinal direction of the housing (11), which are in their initial position (12.1) when no force (30) is applied from the outside to the longitudinal walls (12), characterized by , that at least one spring element (20) is provided in the housing (11), which is arranged between the two longitudinal walls (12) when it is in its initial shape (20.1), wherein the longitudinal walls (12) of the housing (11) have such a small wall thickness (13) that they can be moved towards one another by the action of force (30) from the outside and are elastically deformable in the process and thus assume their loaded position (12.2). and that when a force (30) is applied from the outside, by bringing at least one of the longitudinal walls (12) into its loaded position (12.2), at least one of the spring elements (20) is deformed counter to its spring force between the two longitudinal walls (12) and thus assumes its compressed shape (20.2), wherein when the force (30) is removed, the spring element (20) can be brought back into its original shape (20.1) and the longitudinal walls (12) can be brought back into their original position (12.1). [2] Cooling profile (10) according to claim 1, characterized by that the wall of the housing (11) consists of a sheet metal. [3] Cooling profile (10) according to claim 2, characterized by that the housing (11) consists of a roll-formed sheet metal, the ends of the sheet metal being connected to one another by a weld seam (14). [4] Cooling profile (10) according to one of claims 1 to 3, characterized bythat the spring elements (20) are arranged along the longitudinal direction of the housing (11) and are fixed in the housing. [5] Cooling profile (10) according to one of claims 1 to 4, characterized by that the spring elements (20) in their initial form (20.1) touch both longitudinal walls (12). [6] Cooling profile (10) according to one of claims 1 to 5, characterized by that the spring elements (20) consist of a plastic, in particular of an elastomer or of a plastic foam. [7] Cooling profile (10) according to one of claims 1 to 5, characterized by that the spring elements (20) consist of a spring steel. [8] Cooling profile (10) according to one of claims 1 to 7, characterized by that one or both longitudinal walls (12) of the housing (11) have one or more webs (21) which project into the interior (15) of the housing (11). [9] Cooling profile (10) according to claim 8, characterized bythat the webs (21) serve as a stop for the opposite longitudinal wall (12), so that when a force (30) is applied from the outside to the longitudinal walls (12) and brought into their loaded position (12.2), these can only be moved towards each other until they come into contact with at least one web (21) which is arranged on the opposite longitudinal wall (12). [10] Cooling profile (10) according to one of claims 8 or 9, characterized by that a web (21) and a spring element (20) are always provided alternately along the transverse direction of the housing (11) at the same distance from each other. [11] Cooling profile (10) according to one of claims 1 to 10, characterized by that at least one heat-conducting medium is provided on the outer side (16) of the longitudinal wall (12). [12] Cooling profile (10) according to one of claims 1 to 11, characterized by that the housing (11) is made of aluminum or an aluminum alloy or steel. [13] Cooling profile (10) according to one of claims 1 to 12, characterized by that a cooling medium, preferably a mixture of water and glycol or other single-phase media or multi-phase refrigerants, is provided in the interior (15) of the housing (11).

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