Pressure equalization device

Abstract

Pressure equalization device for a housing, in particular a metallic battery housing, comprising - a base body (2) made of plastic, - a metal lid (3) which faces an outside of the housing, and - a valve element (4) for opening, in particular for emergency opening, wherein the valve element (4) is arranged on the base body (2) and seals against a sealing seat (5) on the base body (2), and - wherein a press connection (6) is formed between the base body (2) and the cover (3).

Description

[0001] The present invention relates to a pressure compensation device for a housing, in particular a battery housing and in particular a battery housing for a vehicle.

[0002] Vehicles that have a rechargeable battery as an energy storage device usually have battery housings in which a large number of battery cells are arranged. During normal operation, temperature changes and / or pressure changes can occur inside the battery housing, for example when the vehicle is driving uphill. Pressure equalization can be achieved using a membrane, as disclosed, for example, in DE 10 2017 003 360 B3. This document also discloses a possibility for emergency degassing using an additional elastomer shield connected in parallel to the membrane. In this case, the pressure equalization device can open via the elastomer shield in an emergency in order to prevent an excessive increase in pressure inside the battery housing, for example due to a fire in one or more battery cells. This is intended, in particular, to protect neighboring battery cells that are still intact.parallel arranged battery housings should be made possible in order to avoid the risk of further spread and damage to other battery cells as far as possible. The known pressure equalisation devices are often made entirely of plastic or entirely of metal. However, in the event of a battery fire as described, very high temperatures can arise so that a solid structure of the pressure equalisation device made of plastic is destroyed and it is possible to intervene in the battery from the outside. Furthermore, it has been found that if the pressure equalisation device made of plastic is mounted on a usually metallic battery housing, damage to the plastic of the pressure equalisation device can occur due to improper handling. With pressure equalisation devices made entirely of metal, secure and permanent attachment of the membrane is particularly difficult.Furthermore, such metallic pressure equalization devices are very heavy.

[0003] It is an object of the present invention to provide an improved pressure compensation device and a housing arrangement which, while being simple and cost-effective to manufacture, can also prevent external intervention in a housing after a possible partial destruction of the pressure compensation device.

[0004] This object is achieved by a pressure compensation device having the features of claim 1. The subclaims show preferred developments of the invention.

[0005] The pressure compensation device according to the invention for a housing, in particular a battery housing, with the features of claim 1 has the advantage that, in addition to the integration of an opening, in particular for emergency degassing, a solid metal substructure is provided, which reliably remains above the opening in the housing at which the pressure compensation device is arranged, especially in the event of emergency degassing and in particular a battery fire. Furthermore, the pressure compensation device according to the invention is extremely easy to install and enables a particularly secure connection to a metallic housing without the pressure compensation device being damaged during installation on the housing.

[0006] This is achieved according to the invention in that the pressure compensation device for a housing has a base body made of plastic and a cover made of metal. The metallic cover is directed towards an outer side of the housing. Furthermore, the pressure compensation device comprises a valve element for an opening for connecting an inner side to an outer side, in particular for an emergency opening, wherein the valve element is fixed to the base body and seals at a sealing seat on the base body. Furthermore, a press connection is formed between the plastic base body and the metallic cover. This ensures a simple and secure connection between the metallic cover and the plastic base body. The press connection connects the two components to one another quickly and easily.Furthermore, the separate metal cover offers the possibility of providing different metal covers for different case manufacturers, depending on the specified requirements and / or design wishes of the case manufacturer.

[0007] Particularly preferably, the metallic cover comprises a fixing device for securing the pressure compensation device to the housing. The fixing device preferably comprises one or more bushings formed integrally with the cover. Particularly preferably, the press connection between the fixing device and the base body is made of plastic.

[0008] The pressure compensation device preferably comprises a ventilation element for continuously ventilating and de-aerating the housing. This provides a continuous ventilation and de-aeration option.

[0009] More preferably, the ventilation element is arranged on the base body. The ventilation element is preferably a membrane or a nonwoven fabric or the like. Particularly preferably, the ventilation element is connected to the plastic base body by means of a first welded joint. The connection between the ventilation element and the base body can be made by means of a welding process, for example, an ultrasonic welding process.

[0010] More preferably, the base body comprises at least a first part and a second part. Both parts are made of plastic. Particularly preferably, the first part and the second part are connected to each other by means of a second welded connection. Alternatively, the first and second parts of the base body are connected by means of a positive and / or non-positive connection, in particular a clip connection.

[0011] The valve element intended for emergency opening is preferably fixed between the first and second parts of the base body by means of a clamp connection. Alternatively, the valve element is connected to a part of the base body by means of a further welded connection.

[0012] In order to enable a secure sealing of the pressure compensation device on the housing, the pressure compensation device further comprises an elastomer seal which rests on an outer side of the housing.

[0013] The pressure equalization device further preferably has a protective element arranged on a side of the pressure equalization device facing the inside of the housing. The protective element is preferably a wire mesh. The protective element serves to keep solids, which can also escape in the event of a battery fire and be thrown against an inside of the pressure equalization device, away from the pressure equalization device. The protective element can also prevent the plastic base body from being directly exposed to flames in the event of a battery fire. This allows the plastic base body to be better protected.

[0014] Furthermore, the present invention relates to a housing arrangement with a metal housing, in particular a battery metal housing and a pressure compensation device according to the invention.

[0015] A preferred embodiment of the invention will be described in detail below with reference to the accompanying drawings. In the drawing: Fig. 1 a schematic, perspective view of a pressure compensation device according to a preferred embodiment of the invention, Fig. 2 a schematic plan view of the pressure compensation device of Fig. 1, Fig. 3 a schematic view from below of the pressure compensation device of Fig. 1, Fig. 4 a schematic sectional view of the pressure compensation device of Fig. 1, Fig. 5 a schematic exploded view of the pressure compensation device of Fig. 1, Fig. 6 is a schematic, partially sectioned view of the pressure compensation device of Fig. 1 to illustrate the continuous ventilation function and Fig. 7 is a schematic, partially sectioned view of the pressure compensation device of Fig. 1 to illustrate the emergency opening function.

[0016] The following is based on the Fig. 1 to 7, a pressure compensation device 1 for a metallic housing 101, in particular a battery metal housing, and a housing arrangement 100 are described in detail.

[0017] As from Fig. 1 and Fig. As can be seen in Figure 4, the pressure compensation device 1 comprises a plastic base body 2 and a metal cover 3. The cover 3 is directed toward an outer side 11 of the pressure compensation device or housing 101, and the base body 2 is directed toward an inner side 12.

[0018] The pressure compensation device 1 is designed to be arranged via a through opening 102 in the housing 101 and to be connected thereto, for example by means of screws.

[0019] The pressure equalization device further comprises a ventilation element 7, which is designed for continuous ventilation and de-aeration and corresponding pressure equalization between the inner side 12 and the outer side 11. The ventilation element 7 is preferably a non-woven element such as a fleece and can comprise one or more layers.

[0020] The pressure compensation device 1 further comprises a valve element 4 for emergency opening, which is fixed to the base body 2. The valve element 4 seals against a sealing seat 5 (see Fig. 4 and Fig. 6) on the base body. The valve element 4 is made of an elastomer material and has an umbrella-like shape.

[0021] Thus, the pressure compensation device 1 is made of two different materials, namely a metal material, in particular aluminum, and a plastic material, in particular a polymer. A press connection 6 is formed between the base body 2 and the cover 3 (see FIG. Fig. 4).

[0022] As shown in detail Fig. As can be seen in Figure 4, the cover 3 has a fixing device 30 in the form of an integrated bushing. Between an outer periphery of the fixing device 30 and a through hole 20 (see Figure 4), a space 22 is formed. Fig. 5) of the base body 2, the press connection 6 is formed. This makes it possible for the pressure compensation device 1 to be firmly connected to a metallic housing, for example, via a screw connection. Since the connection between the pressure compensation device 1 and the metallic housing is established only via the metallic bushings of the fixing device 30, it can be ensured that the metallic cover 3 always remains over the opening in the housing, even if the plastic of the base body melts and / or burns. This prevents unauthorized access to the interior of the housing, even if the base body 2 has melted.

[0023] The fixing device 30 thus has two functions. First, it provides a firm connection between the metal cover 3 and the plastic base body 2 by means of the press connection 6, and second, it fixes the pressure compensation device 1 to the housing 101, e.g., by means of a screw connection.

[0024] As further stated in particular Fig. As can be seen in Figure 5, the base body 2 is made of a first part 21 and a second part 22. A fixed connection, for example a welded connection or a positive and / or non-positive connection, such as a clip connection, is established between the first part 21 and the second part 22.

[0025] The ventilation element 7 in the form of a fleece or the like can be connected to the plastic of the base body 2 in a simple and secure manner, for example by means of a first weld 70 such as an ultrasonic weld. This allows a simple and secure connection of the ventilation element 7 to the base body 2 to be realized. Fig. Figure 4 schematically shows the first welded joint 70 between the ventilation element 7 and the first part 21 of the base body 2. Alternatively, the ventilation element, in particular a fleece, can be fixed to the base body 2 by means of another fastening component, e.g., a ring.

[0026] The first part 21 is connected to the second part 22 by means of a second welded joint 80 (cf. Fig. 4). Preferably, the first and second welded joints are made simultaneously.

[0027] How further from the Fig. 4, Fig. 6 and Fig. As can be seen in Figure 7, the valve element 4 is clamped between the first part 21 and the second part 22 of the base body 2 at a clamping connection 10. This can be done, for example, during pre-assembly of the base body 2. Alternatively, the valve element 4 can also be connected to one or both parts 21, 22 of the base body by means of a further welded connection. The further welded connection can preferably be produced simultaneously with the first and second welded connections 70, 80.

[0028] In order to prevent solid particles, which may be generated in the event of a battery fire and which could be thrown against the inside of the pressure compensation device 1, from damaging it, the pressure compensation device 1 further comprises a protective element 8 in the form of a wire mesh (cf. Fig. 4 and Fig. 5). The wire mesh is relatively tightly woven, preventing solid particles from coming into direct contact with the plastic base body, and in particular the valve element 4, which could cause damage.

[0029] Furthermore, the pressure compensation device comprises an elastomer seal 9, which is arranged in a ring shape on an inner side of the base body 2. In the assembled state, the elastomer seal 9 seals against an outer side of the housing 101.

[0030] In the Fig. 6 and Fig. Figure 7 shows a schematic representation of the basic operation of the pressure compensation device. Fig. Figure 6 shows the normal pressure equalization option via the ventilation element 7, as indicated by arrows A, which represent ventilation of the housing, and B, which represent ventilation of the housing. The ventilation and venting takes place via openings between the base body 2 and the cover 3 and openings 31 on the cover 3. As can be seen from Fig. 2, the openings 31 are formed along the outer circumference of the lid. As further shown in Fig. As can be seen from Figure 6, the valve element 4 is made of elastomer and seals securely at the sealing seat 5 when closed.

[0031] Fig. Figure 7 shows an emergency opening function of the pressure equalization device 1, which can occur, for example, in the event of a cell fire in battery cells inside the housing 101. In this case, a large volume of gas is released within a short time, and the pressure inside the battery housing can rise accordingly. The valve element 4 is now configured such that, starting at a predetermined pressure difference between the inner side 12 and the outer side 11, an emergency opening is performed by the valve element 4. As shown schematically in Fig. 7, as indicated by the arrows C, a large quantity of gas can thus escape via the emergency-opened valve element 4 through the openings 31 in the cover 3. This can prevent further damage and, in particular, further fires to still intact battery cells in the battery housing.

[0032] Thus, the cover 3 can span the opening in the battery housing and be firmly screwed to the housing by the bushing-like fixing devices 30. This allows a continuous metallic connection between the pressure compensation device 1 and the housing 101 to be achieved, so that the metallic connection remains intact even if the plastic material melts. At the same time, manufacturing-related advantages can be achieved, particularly through the welded connection of the ventilation element 7 to the base body 2 and the fixation of the umbrella-like valve element 4.

[0033] Since the base body 2 is made of plastic, the two parts 21, 22 of the base body, the valve element 4, and the ventilation element 7, can form a pre-assembled assembly. This makes it possible, for example, to provide different metal covers for different battery manufacturers, which can be designed according to the battery manufacturer's requirements. The standardized interface at the press connection 6 allows for easy interchangeability of the covers for different battery manufacturers.

[0034] It should be noted that it is of course also conceivable that the pressure compensation device 1 can be designed only as a burst protection for emergency opening without a ventilation element 7. 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] DE 10 2017 003 360 B3

[0002]

Claims

[1] Pressure compensation device for a housing, in particular a metallic battery housing, comprising - a base body (2) made of plastic, - a cover (3) made of metal, which is directed towards an outer side of the housing, and - a valve element (4) for opening, in particular for emergency opening, wherein the valve element (4) is arranged on the base body (2) and seals against a sealing seat (5) on the base body (2), and - wherein a press connection (6) is formed between the base body (2) and the cover (3). [2] Pressure compensation device according to claim 1, wherein the cover has a fixing device (30) for fixing the pressure compensation device to the housing. [3] Pressure compensation device according to claim 2, wherein the press connection (6) is formed between the fixing device (30) and the base body (2). [4] Pressure compensation device according to one of the preceding claims, further comprising a ventilation element (7) arranged for a continuous gas exchange between an inner side (12) and an outer side (11) of the pressure compensation device. [5] Pressure compensation device according to claim 4, wherein the ventilation element (7) is fixed to the base body (2), in particular by means of a first welded connection (70). [6] Pressure compensation device according to one of the preceding claims, wherein the base body (2) has a first part (21) and a second part (22) which are firmly connected to one another. [7] Pressure compensation device according to claim 6, wherein the first part (21) is connected to the second part (22) by means of a second welded connection (80) or wherein the first part (21) is connected to the second part (22) by means of a positive and / or non-positive connection, in particular a clip connection. [8] Pressure compensation device according to claim 6 or 7, wherein the valve element (4) is fixed by means of a clamping connection (10) between the first part (21) and the second part (22). [9] Pressure compensation device according to one of the preceding claims, further comprising an elastomer seal (9) which is arranged on the base body (2), wherein the elastomer seal (9) is designed to seal on an outer wall of the housing. [10] Pressure compensation device according to one of the preceding claims, further comprising a protective element (8), in particular a wire mesh, which is arranged on a side of the base body (2) directed towards the inner side (12), wherein the protective element (18) is designed to protect the pressure compensation device from solids. [11] Housing arrangement (10) comprising a metal housing and pressure compensation device according to one of the preceding claims.

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