Pressure equalization device

Abstract

Pressure compensation device (20) for compensating an internal pressure in a receiving housing of an electrochemical or electrotechnical device, in particular for a battery housing, with a housing (20.3) that has at least one gas passage opening (20.4) that forms a gas-permeable connection between an inner side (20.1) and an outer side (20.2) of the housing (20.3), wherein the gas passage opening (20.4) is blocked by means of a gas-permeable or gas-tight membrane (40), wherein the membrane (40) is assigned a bursting element (30) that is designed and positioned such that upon deformation of the membrane (40) in the direction of the outer side (20.2), it is destroyed at least at one point under the action of the bursting element (30) in order to create a flow connection from the inner side (20.1) to the outer side (20.1) through the gas passage opening (26.2), characterized in that the membrane (40) with its inside (20.1) of the housing (20.3) is connected, in particular materially connected, to the bursting element (30).

Description

[0001] The invention relates to a pressure equalization device for equalizing internal pressure in a receiving housing of an electrochemical or electrotechnical device, in particular for a battery housing, with a housing having at least one gas passage opening that forms a gas-permeable connection between an inner and an outer side of the housing, wherein the gas passage opening is blocked, in particular at least partially covered, by means of a gas-permeable or gas-tight membrane, wherein a bursting element is associated with the membrane, which is designed and positioned such that, in the event of deformation of the membrane towards the outside, it is destroyed at least at one point by the action of the bursting element in order to create a flow connection from the inside to the outside through the gas passage opening.

[0002] Such pressure equalization devices according to the invention serve to equalize the internal pressure in a receiving housing. During normal operation, certain pressure fluctuations between the interior of the receiving housing and the environment can be equalized via the diaphragm if it is gas-permeable. If a non-gas-permeable diaphragm is used, then additional measures must or may be provided to compensate for the normal pressure fluctuations.

[0003] If the internal pressure inside the receiving housing, to which the inner side of the pressure equalization device faces, suddenly increases, this pressure must be released immediately to prevent the receiving housing from bursting. For this purpose, a bursting element is provided in the pressure equalization devices according to the invention, which then ruptures the diaphragm at least at one point. In the pressure equalization devices according to the invention, this can be achieved by deforming the diaphragm so severely during such an impermissible pressure increase that it is ruptured at the bursting element, for example, by being cut. The internal pressure of the receiving housing can then be released through the gas passage opening towards the outside of the pressure equalization device and thus towards the environment.

[0004] A pressure equalization device is known from DE 10 2011 080 325 A1. This known pressure equalization device has a housing with a flanged section featuring bores for attachment to a battery housing. The housing covers the edge of an opening in the battery housing. The housing is connected to a diaphragm that blocks a gas passage opening in the housing. The diaphragm is tensioned between the support element and a clamping piece and is held in place with a circumferential seal. A housing-like protective element is also used, which has a cutting element in a central area. This cutting element faces the diaphragm. The protective element serves to prevent access to the diaphragm from the outside of the pressure equalization device. The protective element has gas passage openings. The diaphragm is gas-permeable but essentially water-repellent.The water-repellent function ensures that water from the environment cannot penetrate from the outside to the inside, or only to a negligible extent. During normal operation, gas equalization between the environment and the battery housing can occur via the membrane. This is possible because the membrane is gas-permeable. If a sudden burst pressure occurs, for example due to a malfunction in the battery housing, the membrane bulges outwards. A gap is maintained between the cutting element and the outer surface of the membrane, which defines the permissible deformation of the membrane in such a case of damage. If the membrane bulges beyond the permissible deformation, it comes into contact with the cutting element, which is designed as a point. The cutting element damages the membrane, causing it to rupture. The gas can then quickly escape from the battery housing into the environment through the gas vent.This prevents the battery casing from exploding.

[0005] The pressure equalization device known from the prior art is complex in design. Furthermore, the unavoidable dimensional tolerances between the individual device components do not guarantee that the cutting element is always positioned at precisely the same distance from the membrane surface in different pressure equalization devices of the same design. Therefore, a precisely reproducible bursting behavior in the event of overload is not achieved.

[0006] It is therefore an object of the invention to provide a pressure equalization device of the type mentioned at the outset, with which a reproducible bursting behavior is reliably ensured.

[0007] This problem is solved by connecting the membrane, with its inner surface facing the inside of the housing, to the bursting element, in particular by a material bond.

[0008] If, in the event of an overload, an impermissible pressure increase occurs in the receiving chamber of the housing, and thus on the inside of the diaphragm, the diaphragm bulges towards the outside of the housing. Since the diaphragm's inner surface is connected to the rupture element, it cannot deform in this area, or not to the same extent, as in the rest of the area covering the gas passage opening. Consequently, the diaphragm ruptures in the area of ​​the rupture element due to these unequal deformation conditions, thus releasing the gas passage opening. The pressure can then escape from the receiving housing to the outside.

[0009] This method guarantees reproducible burst behavior, since, unlike prior art, a tolerance-laden distance between a cutting tip and the outer surface of the membrane does not need to be set; instead, the membrane is directly connected to the bursting element. Surprisingly, it has been shown that the bursting behavior of the membrane is significantly improved by coupling its inner surface to the bursting element. In particular, this improves the response to an impermissible pressure increase.

[0010] According to the invention, the bursting element, following its connection with the membrane, can form a body edge at which the membrane tears or is cut off due to the pressure differences between the inside and outside of the housing. As soon as a tear or cut is initiated in the membrane, it is weakened to such an extent that it ruptures and abruptly releases the gas passage opening.

[0011] Advantageously, the rupture element is positioned so that it projects into the area of ​​the gas passage opening, and the connection to the membrane, in particular the positive-locking connection, is located at least partially within the projecting portion. This allows the rupture element to initiate the tear in a membrane area subject to significant deformation. Furthermore, the rupture element, which rests against the inner surface of the membrane, supports the membrane against external pressure. Such pressure can occur, for example, when water pressure is applied externally, generated by a cleaning device (hose, steam cleaner). This support reduces the risk of unintentional membrane damage in such an operating position.

[0012] A preferred embodiment of the invention may be such that the membrane has a circumferential edge by means of which it is connected around the circumference to the housing, that the bursting element projects into the area of ​​the gas passage opening, and is connected to the membrane in an area within the circumferential edge, in particular by a material bond.

[0013] The connection preferably extends in a central area or at least partially into the central area of ​​the membrane.

[0014] One possible embodiment of the invention is such that the membrane covers the gas passage opening with a surface area, wherein this surface area has a maximum free coverage length, and that the length with which the bursting element extends into the area of ​​the gas passage opening is at least 30% of this free coverage length, and / or that the minimum longitudinal extent of the material-bonded connection in one direction is at least 25% of this free coverage length. This achieves both good internal support of the membrane and good bursting behavior.

[0015] Another possible variant of the invention is that the gas passage opening is limited by a ring-shaped surrounding wall, and that the bursting element projects radially inwards from the wall into the area of ​​the gas passage opening.

[0016] According to a preferred embodiment of the invention, the bursting element may have a connecting section comprising a connecting surface facing the membrane, to which the membrane is bonded, the connecting surface transitioning into an edge extending transversely to the connecting surface, in particular an edge, preferably a cutting edge, and preferably the bond extending to the edge, in particular to the cutting edge. This measure further improves the reproducible bursting behavior, as it provides a defined positioning for tear initiation at the edge, in particular at the cutting edge.

[0017] If the housing is provided to have a cover section with a circumferential recess, preferably designed as a depression, surrounding the gas passage opening, and if the membrane is attached to or inserted into the recess with its circumferential edge, and a connecting area of ​​the circumferential edge is materially bonded to a connecting section of the recess, then a precise positioning of the membrane is achieved in a simple manner.

[0018] In particular, it can also be provided that the membrane is back-injected into the housing using a plastic injection molding process. The connection and sealing of the membrane, the housing, and the bursting element are integrated into the injection molding process. In this case, the membrane is then materially bonded to the housing. However, within the scope of the invention, it is also possible for the membrane to be connected to a manufactured housing, in particular materially bonded.

[0019] It is particularly advantageous if the connecting section of the bursting element, to which the membrane is bonded, is flush with the surface of the connecting section. This allows the connection between the bursting element and the membrane, and between the housing and the bursting element, to be made in a single process step.

[0020] According to one embodiment of the invention, the housing may be provided with a spacer on its outer surface which carries a cover spaced apart from the membrane, and which covers the membrane with a cover section at a distance from the outer surface of the membrane, in which case the membrane is protected on its outer surface from mechanical stress.

[0021] Advantageously, the spacer can also be designed to have at least one ventilation opening, creating a spatial connection between the outer surface of the membrane and the environment. Pressure equalization with the environment can occur via this ventilation opening. If, for example, the membrane is gas-permeable, pressure equalization between the inner and outer surfaces can occur during normal operation via the membrane and the ventilation opening (breathing function).

[0022] If it is provided that the spacer is designed at least partially as a ring body or has such a ring body, that the ring body has an outer wall which is at a distance from an edge of the cover, and that at least one ventilation area in the form of a space is formed between the edge and the outer wall, then mechanical access protection can be easily implemented.

[0023] For easy attachment of the deck section, the spacer can be provided with a mounting point and retaining element located above and spaced apart from the outer surface of the membrane. The deck section is attached to the retaining element via the spacer, and the deck section is made of a flexible material. In the event of a rupture, the pressure in the gas flow deforms the deck section. This allows a large opening cross-section, previously covered by the deck section, to be suddenly released.

[0024] This results in a compact design in a simple way if the spacer has ribs that hold the mounting point above the outer surface of the membrane, and gas guidance areas are formed between the ribs.

[0025] To ensure safe operation in the event of an impermissible pressure increase in the receiving housing, the diaphragm is deformed towards the outside, in particular bulged, and the diaphragm is destroyed at least at one point under the influence of the bursting element in order to create a flow connection from the inside to the outside through the gas passage opening.

[0026] Within the scope of the invention, the membrane can be waterproof or substantially waterproof. The membrane can be designed, in particular, as a sheet element, especially as a plastic film. The membrane can be made of a polyester material, for example polyethylene terephthalate or polycarbonate, or can consist entirely of such a material.

[0027] The membrane is preferably designed in the form of a circular disc. This results in advantageous properties when the membrane is deformed.

[0028] The invention will be explained in more detail below with reference to exemplary embodiments illustrated in the drawings. The drawings show: Fig. 1: in perspective view from above a protective device 10, Fig. 2: the protective device 10 after Fig. 1 in exploded view, Fig. 3: the protective device 10 according to Fig. 1 in full cut, Fig. 4 a further protective device 10 according to the invention in perspective view and Fig. 5: the representation according to Fig. 4 in full cut.

[0029] Fig. Figure 1 shows a perspective view of a protective device 10 with a pressure equalization device 20. This pressure equalization device 20 has a housing 20.3. The housing 20.3 forms an outer surface 20.2 and an inner surface 20.1.

[0030] If the housing 20.3 is operationally installed with a receiving housing, in particular an electrochemical or electrotechnical device, for example a battery housing, then the inner side 20.1 is assigned to the interior of the receiving housing. The outer side 20.2, on the other hand, faces away from the interior of the receiving housing and is assigned to the environment.

[0031] As the Fig. 2 and Fig. As shown in Figure 3, the housing 20.3 forms a cover 21 in the area of ​​the outer surface 20.2. This cover is closed off at the top with a deck section 28, which forms a cover surface. Opposite the deck section 28, the housing 20.3 has a sealing section on the cover 21.

[0032] The sealing section can be formed as an annular circumferential projection on the housing 20.3 and preferably projects in a radial direction beyond an outer surface of the housing 20.3.

[0033] The sealing section forms a mounting surface facing the inner side 20.1. This mounting surface is preferably designed as a ring-shaped, circumferentially closed surface that further preferably extends in a radial direction. A seal can be provided circumferentially in the area of ​​the mounting surface, which, for example, is molded in the area of ​​the sealing section using a two-component injection molding process and projects towards the inner side 20.1.

[0034] In addition to or as an alternative to the seal, an energy direction indicator can also be provided protruding from the mounting surface. The energy direction indicator can be designed as a circumferential bead. It can be used to weld the housing 20.3 to the receiving housing in a circumferentially tight manner.

[0035] How Fig. As shown in Figure 2, the housing 20.3 can have a receptacle 24 to which a membrane 40 is attached with its circumferential edge, preferably by a material bond. Advantageously, the membrane 40 is designed in the form of a circular disk, such that the edge of this circular disk forms a connection area 43 with which the membrane 40 can be attached circumferentially to the receptacle 24.

[0036] Preferably, the receptacle 24 is designed in the form of a recess 26 which is recessed into the top surface of the cover section 28. The recess 26 thus forms a circumferential connecting section 25 for the circumferential edge of the membrane 40.

[0037] The top surface 28 of the housing 20.3 transitions into an outer wall 27 of the cover 21.

[0038] The housing 20.3 can form a circumferential inner wall surrounding a gas passage opening 20.4. The gas passage opening 20.4 can be closed by means of the membrane 40. The membrane 40 is designed as a sheet element and preferably consists of a gas-permeable or gas-tight plastic film. The membrane 40 is essentially watertight and preferably sufficiently tear-resistant to prevent unintended failure of the membrane 40 due to exposure to water pressure from the outside 20.2.

[0039] The diaphragm 40 has an outer surface 41 which faces the outer surface 20.2 of the housing 20.3. Opposite the outer surface 41, the diaphragm 40 has an inner surface 42 which faces the inner surface 20.1 of the housing 20.3.

[0040] How Fig. As can be seen in Figure 2, the membrane 40 has a circumferential connection area 43, which can be, in particular, annular in shape. The membrane 40 is gas-tightly connected to the connection section 25 of the receptacle 24 by means of this connection area 43, preferably by a material bond. In particular, the membrane 40 can be back-injected into the housing 20.3 using a plastic injection molding process.

[0041] The connecting section 25 is designed as an annular circumferential surface on the receptacle 24. In particular, the connecting section 25 runs an annularly around the gas passage opening 20.4.

[0042] The Fig. 1 and Fig. Figure 2 further shows that a bursting element 30 is formed on the housing 20.3, which, as in the present case, may have a cutting element. Preferably, the bursting element 30 is integrally connected to the housing 20.3. Particularly preferably, the bursting element 30 is integrally connected to the inner wall of the housing 20.3.

[0043] As the drawings show, the bursting element 30 is connected to the housing 20.3 via a coupling section 31, which can also be designed as a spring section. Furthermore, the entire bursting element 30 can also be spring-elastic or form the spring section itself.

[0044] The bursting element 30 has an end section 34 at its free end, which forms an edge, preferably a cutting edge 34, on its side facing the outside 20.2, as Fig. 2 shows.

[0045] Additionally or alternatively, it may also be provided that one or more edges of the bursting element 30 are formed with a rim or edge, preferably a cutting edge 33, 34.

[0046] The aforementioned cutting edges 33, 34 can be point-shaped, linear, curved or otherwise formed.

[0047] In the present embodiment, the bursting element 30 is coupled to the housing 20.3, preferably connected in one piece via the coupling piece 31. The bursting element 30 projects from the coupling piece 31 into the area that forms the gas passage opening 20.4.

[0048] The bursting element 30 tapers continuously from the coupling piece 31 towards the end section 35. It is possible that the cutting edges 33, 34 converge from the coupling piece 31 towards the end section 35 and run in a linear fashion.

[0049] How Fig. As shown in Figure 2, the connecting section 32 of the bursting element 30 can be flush with the surface of the connecting section 25. In this way, a continuous, material-bonded connection can be made between the membrane 40 at its circumferential connecting section 43 and simultaneously at the connecting section 32. However, this is not strictly necessary. In particular, the connecting section 32 can also be arranged at a distance from the receptacle 24.

[0050] How Fig. Figure 3 shows that the bursting element 30 extends into the middle area of ​​the membrane 40, thus supporting it here in the area of ​​the inner surface of the membrane 42.

[0051] The Fig. 2 and Fig. Figure 3 further illustrates that the housing 20.3 of the pressure equalization device 20 can have a centering projection 23 following the mounting section 22. This centering projection 23 is designed in the form of a circumferential rib, as shown. Fig. Figure 3 shows. The centering projection 23 allows the housing 20.3 to be aligned in an opening in the receiving housing, to which the pressure equalization device 20 can be attached.

[0052] The Fig. 2 and Fig. Figure 3 further shows that a spacer 50 can be connected to the housing 20.3. The spacer 50 can be designed as a ring body.

[0053] Fig. Figure 2 shows that the spacer 50 has a bottom surface 52 by means of which it can be placed on the deck section 28 and connected to it, preferably by a material bond. Adjoining the bottom surface 52, the spacer 50 has a projection 51 extending upwards towards the outer surface 20.2. The projection 51 is provided at its upper end with several ventilation openings 55 in the form of recesses.

[0054] The spacer 50 surrounds a gas guidance area 56, which is formed above the outer surface of the membrane 41.

[0055] The projection 51 is integrally formed with webs 57. In the present embodiment, three webs 57 are used, which are connected to each other in the area of ​​the center of the gas guide area 56 and which can be arranged offset from each other by 120°. A fastening projection 58 is provided in the area where the webs 57 meet. The fastening projection 58 extends upwards from the webs 57 towards the outer surface 20.2 and has a retaining element 58.1 that terminates in a head 58.2.

[0056] A cover 60 can be connected to the spacer 50. The cover 60 has a deck section 61 in which a mounting receptacle 62 is incorporated. Furthermore, the deck section 60 has a circumferential edge 63.

[0057] To mount the cover 60, it is connected to the spacer 50. This is easily achieved by connecting the cover section 61 to the mounting bracket 58.

[0058] In this case, the cover 60 may be made of a flexible material, for example, a rubber-like material. The cover section 61 can then be stretched in the area of ​​the mounting receptacle 62 and guided over the head 58.2, so that it subsequently fits against the retaining part 58.1.

[0059] Fig. Figure 3 shows that the deck section 61 of the cover 60 rests on the projection 51 at its end when assembled. Since the ventilation openings 55 are recessed relative to the free end of the projection 51, a gas-carrying connection can be established here between the outer surface of the membrane 41 and the environment.

[0060] Fig. Figure 3 further shows that for this gas-carrying connection the circumferential edge 63 of the cover 60 is also at a distance from an outer wall 53 of the projection 51, wherein the outer wall 53 is formed in a ring-shaped circumferential form.

[0061] When the pressure equalization device 20 is mounted on a receiving housing (not shown), the inner side 20.1 of the housing 20.3, and thus also the inner side of the diaphragm 42, is located within the receiving housing. The outer side 20.2, and thus also the outer side 41 of the diaphragm 40, is located in the environment.

[0062] If the membrane 40 is designed as a gas-permeable membrane 40, pressure differences between the environment and the interior of the receiving housing can be equalized via the membrane 40 during normal operation in order to fulfill a breathing function.

[0063] This pressure equalization occurs such that, for example, if the pressure inside the receiving housing increases compared to the surroundings, gas passes through the gas-permeable membrane 40 into the gas guide area 56 of the spacer 50. From there, this gas is discharged into the surroundings via the ventilation openings 55. Similarly, if the pressure inside the receiving housing decreases, pressure equalization can occur in the opposite direction.

[0064] When the pressure in the receiving housing suddenly increases, this pressure is exerted on the inner surface of the membrane 42. This causes the membrane 40 to deform towards the outer surface 20.2, specifically bulging towards the outer surface 20.2. Different deformation states occur on the membrane 40. Where the inner surface of the membrane 42 is connected to the adjacent connecting section 32 of the bursting element 30, particularly where it is bonded, the membrane 40 is not deformed or is deformed less than in the surrounding area covering the gas passage opening 20.4. Due to these different deformation states, the membrane 40 is ruptured in the area of ​​the connecting section 32 of the bursting element 30.In particular, a tear in the membrane 40 is initiated at at least one of the above-described cutting edges 33, 34 of the end section 35 and / or the connecting section 32 due to the prevailing pressure differences.

[0065] In this way, the membrane 40 is damaged and subsequently destroyed. This abruptly releases at least part of the gas passage opening 20.4. The released gas flow reaches the cover 60. If the gas flow is so strong that it cannot be discharged through the ventilation openings 55, the flexible cover section 61 bends outwards, abruptly opening a larger cross-section for the gas flow to escape.

[0066] In the Fig. 4 and Fig. Figure 5 shows a further embodiment of the invention. As this illustration demonstrates, the ventilation openings 55 are formed in the area between the underside 52 of the spacer 50 and the top section 28 of the housing 20.3. Otherwise, the embodiment corresponds to the Fig. 4 and Fig. 5 according to the exemplary embodiment Fig. 1-3. Therefore, to avoid repetition, reference can be made to the above statements. QUOTES INCLUDED IN THE DESCRIPTION

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

[0000] DE 10 2011 080 325 A1

[0004]

Claims

[1] Pressure equalization device (20) for equalizing an internal pressure in a receiving housing of an electrochemical or electrotechnical device, in particular for a battery housing, comprising a housing (20.3) having at least one gas passage opening (20.4) which forms a gas-permeable connection between an inner side (20.1) and an outer side (20.2) of the housing (20.3), wherein the gas passage opening (20.4) is blocked by means of a gas-permeable or gas-tight membrane (40), wherein the membrane (40) is associated with a bursting element (30) which is designed and positioned such that, in the event of deformation of the membrane (40) towards the outer side (20.2), it is destroyed at least at one point by the action of the bursting element (30) in order to create a flow connection from the inner side (20.1) to the outer side (21.1) through the gas passage opening (26.2), characterized by, that the membrane (40) is connected to the bursting element (30) with its inner membrane surface (42) facing the inside (20.1) of the housing (20.3), in particular by a material bond. [2] Pressure equalization device (20) according to claim 1, characterized by , that the bursting element (30) has a connecting section (32) which has a connecting surface facing the membrane (40) to which the membrane (40) is materially bonded, that the connecting surface transitions into an edge, in particular an edge, preferably a cutting edge (33, 34), extending transversely to the connecting surface, and that preferably the materially bonded connection extends to the edge, in particular the edge, preferably the cutting edge (33, 34). [3] Pressure equalization device (20) according to claim 1 or 2, characterized bythat the membrane (40) has a circumferential edge by means of which it is connected around its circumference to the housing (20.3), that the bursting element (30) projects into the area of ​​the gas passage opening (20.4), and is connected to the membrane (40) in an area within the circumferential edge, in particular by a material bond. [4] Pressure equalization device (20) according to claim 3, characterized by , that the membrane (40) covers the gas passage opening (20.4) with a surface area, wherein this surface area has a maximum free coverage length, and that the length with which the bursting element (30) extends into the area of ​​the gas passage opening is at least 30% of this free coverage length, and / or that the minimum longitudinal extent of the materially bonded connection in one direction is at least 25% of this free coverage length. [5] Pressure equalization device (20) according to one of claims 1 to 4, characterized by, that the gas passage opening (20.4) is bounded by an annularly surrounding wall, and that the bursting element (30) projects radially inwards from the wall into the area of ​​the gas passage opening (20.4). [6] Pressure equalization device (20) according to one of claims 1 to 5, characterized by , that the housing (20.3) has a cover section (28) with a circumferential receptacle (24), which is preferably designed as a recess (26), and which surrounds the gas passage opening (20.4), and that the membrane (40) is attached to or inserted into the receptacle (24) with its circumferential edge, and that a connecting area (43) of the circumferential edge is connected circumferentially to a connecting section (25) of the receptacle (24) in a materially bonded manner. [7] Pressure equalization device (20) according to claim 6, characterized by, that the connecting section (32) of the bursting element (30), with which the membrane (40) is materially bonded, transitions flush into the connecting section (25). [8] Pressure equalization device (20) according to one of claims 1 to 7, characterized by , that the housing (20.3) in the area of ​​the outside (20.2) carries a spacer (50) which carries a cover (60) spaced apart from the membrane (40), which covers the membrane (40) at a distance from the membrane outside (41) with a cover section (61). [9] Pressure equalization device (20) according to claim 8, characterized by that the spacer (50) has at least one ventilation opening (55) which creates a spatial connection between the outer surface of the membrane (41) and the environment. [10] Pressure equalization device (20) according to claim 8 or 9, characterized bythat the spacer (50) is designed at least partially as a ring body or has such a ring body, that the ring body has an outer wall (53) which is at a distance from an edge (63) of the cover (60), and that at least one ventilation area in the form of a space is formed between the edge and the outer wall. [11] Pressure equalization device (20) according to one of claims 8 to 10, characterized by , that the spacer (50) has a fastening attachment (58) with a retaining part (58.1) in an area above and spaced apart from the outer surface of the membrane (41), that the deck section (61) is attached to the retaining part (58.1) with the spacer (50), and that the deck section (61) is made of a flexible material. [12] Pressure equalization device (20) according to claim 11, characterized by, that the spacer (50) has webs (57) which hold the fastening attachment (58) above the outer surface of the membrane (41), and that gas guidance areas (56) are formed between the webs. [13] Pressure equalization device according to any one of claims 1 to 12, characterized by , that in the event of an impermissible pressure increase in the receiving housing, the membrane (40) is deformed in the direction of the outer side (20.2) facing away from the interior of the receiving housing, in particular bulging, and that the membrane (40) is destroyed at least at one point under the influence of the bursting element (30) in order to create a flow connection from the inside (20.1) to the outside (21.1) through the gas passage opening (26.2).

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