Pressure equalization device and housing

Abstract

Pressure equalization device comprising a grid-shaped cage (1) with a gas passage opening (3) through which gas can flow in the flow direction (2), which connects an inner (4) and an outer (5) of the pressure equalization device in a flow-conducting manner, wherein the gas passage opening (3) has an end face (6) facing the outer (5) which is covered by a gas-permeable membrane (7), wherein the membrane (7) is associated with a pressure relief valve (8) designed as burst protection in a functionally parallel circuit, wherein the membrane (7) and the pressure relief valve (8) together spatially separate the inner (4) and outer (5) from each other, wherein the membrane (7) has a circular functional surface (10) which is bounded by a first outer diameter (9), wherein the pressure relief valve (8) is designed in an annular shape, with an inner diameter (11),which encloses the gas passage opening (3) circumferentially and has a sealing lip (12) with a second outer diameter (13) which contacts a sealing surface (14) of the cage (1) under elastic preload, wherein the sealing lip (12) can be lifted from the sealing surface (14) and brought into an open position for emergency degassing of the inner surface (4) and for providing a flow-conducting connection between the inner surface (4) and the outer surface (5), and wherein the end face (6) and the membrane (7) are arranged adjacent to each other in the flow direction (2) at a distance (15), characterized in that the ratio of the first outer diameter (9) of the functional surface (10) and the second outer diameter (13) of the sealing lip (12) is 0.9 to 1.1.

Description

Technical field

[0001] The invention relates to a pressure equalization device and a housing therefor, wherein the pressure equalization device comprises a grid-shaped cage with a gas passage opening through which flow is directed, the gas passage opening connecting an inner and an outer side of the pressure equalization device in a flow-conducting manner, wherein the gas passage opening has an end face facing the outer side which is covered by a gas-permeable membrane, wherein the membrane is associated with a pressure relief valve designed as burst protection in a functionally parallel circuit, wherein the membrane and the pressure relief valve together spatially separate the inner and outer sides from each other, wherein the membrane has a circular functional surface which is bounded by a first outer diameter, wherein the pressure relief valve is designed in an annular shape, with an inner diameterwhich encloses the gas passage opening on its outer circumference and has a sealing lip with a second outer diameter which contacts a sealing surface of the cage under elastic preload, wherein the sealing lip can be lifted from the sealing surface and brought into an open position for emergency degassing of the inside and for providing a flow-conducting connection between the inside and outside, and wherein the end face and the membrane are arranged adjacent to each other at a distance in the direction of flow. State of the art

[0002] Such a pressure equalization device is known from DE 11 2019 005 336 T5. The overpressure valve, designed as burst protection, consists of a rubber whose rate of change of tensile strength, determined according to a disclosed test method, is 95% to 120%.

[0003] The material from which the pressure relief valve is made should be advantageous in terms of good heat resistance.

[0004] The respective outer diameters of the functional surface of the membrane and the sealing lip differ significantly. In the disclosed embodiment, the outer diameter of the sealing lip is approximately three times larger than the outer diameter of the functional surface of the membrane.

[0005] It is stated that the gas-permeable membrane has an outer diameter that is smaller than the inner diameter of the annular pressure relief valve. The inner diameter of the pressure relief valve is large enough to accommodate the gas-permeable membrane.

[0006] In this respect, this pressure equalization device is similarly designed to the pressure equalization device described below in EP 3 385 584 B1 and therefore also has the same disadvantages if there is little installation space available for the pressure equalization device, especially if the diameter of the pressure equalization device is limited by its installation space and is very small.

[0007] Another pressure equalization device and a housing for it are known from EP 3 385 584 B1. Due to the functionally parallel connection of the diaphragm and the pressure relief valve, the diaphragm remains undamaged even during emergency degassing of the inner surface, so that the diaphragm of the pressure equalization device, and thus the pressure equalization device itself, can continue to be used unchanged after emergency degassing. The diaphragm and the pressure relief valve are arranged coaxially to each other, such that the first outer diameter of the functional surface of the diaphragm essentially corresponds to the inner diameter of the pressure relief valve.

[0008] The membrane is positioned directly on the outer face of the gas passage opening, so that the functional area of ​​the membrane corresponds to the cross-section of the gas passage opening.

[0009] During normal use of the pressure equalization device, i.e., when the pressure difference between the inside and outside is not critical and emergency degassing of the inside is not required, the best possible permeability of the membrane is generally important. At the same time, high resistance to water pressure from the outside is advantageous.

[0010] If only a small amount of installation space is available for the pressure equalization device, especially if the diameter of the pressure equalization device is limited by its installation space and is very small, the functional area of ​​the diaphragm would also be correspondingly small in the previously known pressure equalization device, so that in this case pressure equalization between the inside and outside would no longer function satisfactorily during the intended use of the pressure equalization device.

[0011] The previously known pressure equalization device can be used in housings that enclose electronic components or a chemical reactor.

[0012] From DE 10 2023 125 545 A1 a valve device and a battery housing with such a valve device are known.

[0013] The valve device comprises a base body with a plate-shaped, in particular annular disk-shaped, support element made of a hard component, which defines a gas passage opening and has a cover side and a connection side. The valve device also comprises a valve assembly covering the gas passage opening and connected to the base body, and a soft component for connecting to a support component, the soft component being designed as an activatable adhesive material. Description of the invention

[0014] The invention is based on the objective of further developing a pressure equalization device of the type mentioned above and a housing thereof in such a way that the pressure equalization device ensures good pressure equalization even when the outer diameter of the pressure equalization device is small. The effective area of ​​the diaphragm for the breathing function should be maximized in relation to the effective area of ​​the overpressure valve for an emergency degassing function.

[0015] This problem is solved according to the invention by a pressure equalization device having the features of claim 1 and by a housing having the features of claim 3.

[0016] Advantageous embodiments of the pressure equalization device are referred to in the claims directly or indirectly related to claim 1.

[0017] To solve the problem, a pressure equalization device and a housing with such a pressure equalization device are provided, in which the ratio of the first outer diameter of the functional surface to the second outer diameter of the sealing lip is 0.9 to 1.1. This ratio ensures that the functional surface and the pressure relief valve have essentially the same outer diameters, thereby maximizing the utilization of the interior space within the cage for both the diaphragm and the pressure relief valve. Consequently, the functional area of ​​the diaphragm and the emergency degassing rate through the pressure relief valve are each maximized relative to the diameter of the pressure equalization device.

[0018] It is advantageous that the functional area of ​​the membrane is significantly larger than the cross-sectional area through the gas passage opening.

[0019] Furthermore, the functional area is maximized in relation to the outer diameter of the pressure equalization device.

[0020] With respect to the outer diameter of the pressure equalization device, the design according to the invention not only maximizes the breathing function of the membrane, but also the emergency degassing rate through the overpressure valve.

[0021] The pressure relief valve can be designed as a convexly protruding shield and made of a rubber-elastic sealing material. Due to the convex protrusion of the shield, the sealing lip rests on the sealing surface of the cage under elastic preload, creating a tight seal.

[0022] During normal, intended use of the pressure equalization device, breathing between the inner and outer surfaces occurs exclusively through the functional area of ​​the diaphragm. The overpressure valve is closed in this process.

[0023] Only when the pressure difference between the inside and outside exceeds a certain threshold does the pressure relief valve open, thus reliably preventing diaphragm rupture through subsequent pressure equalization. The parallel connection of the diaphragm and the pressure relief valve provides effective diaphragm burst protection.

[0024] Furthermore, the invention relates to a housing comprising a pressure equalization device as described above. The pressure equalization device according to the invention is fundamentally suitable for all components with closed housings where pressure differences between the inside and outside could lead to damage or failure of the component. At the same time, the membrane ensures that no water and / or contaminants can pass from the outside to the inside.

[0025] The housing can be formed, for example, by battery housings, inverters, electric motors or automotive headlights, with the housings usually having an enclosed dead volume.

[0026] In a hermetically sealed enclosure, both positive and negative pressures can occur inside the enclosure due to heating / cooling during operation or due to atmospheric pressure fluctuations.

[0027] Housings are becoming increasingly lighter and therefore thinner-walled, meaning they must be protected from undesirably high pressure differentials due to their thinness. This is where the pressure equalization device comes in. The pressure equalization element reduces pressure peaks, thereby limiting the potential pressure loads on the housing. Essential requirements for a well-functioning pressure equalization device include good gas permeability during normal operation, high gas permeability from the inside to the outside during emergency degassing, high water resistance, good resistance to oils and dust, and good mechanical robustness. Brief description of the drawing

[0028] An embodiment of the pressure equalization device according to the invention is explained in more detail below with reference to the figure. The figure shows a schematic representation of an embodiment of a pressure equalization device. Implementation of the invention

[0029] The pressure equalization device can be used for all types of housings 17 where unwanted pressure differences between the inside 4 and outside 5 are to be avoided.

[0030] The pressure equalization device is inserted into the housing 17, which is shown only schematically.

[0031] The pressure equalization device comprises the grid-shaped cage 1, which can be made, for example, of a tough polymeric material. The cage 1 has a gas-permeable opening 3, the direction of flow being indicated by the reference numeral 2. The gas-permeable opening 3 connects the inner surface 4 and the outer surface 5 in a flow-conducting manner, and in the illustrated embodiment, the gas-permeable opening 3 is cylindrical.

[0032] If the membrane 7 were to directly touch the end face 6 of the gas passage opening 3 facing the outside 5, its functional area 10 would be only comparatively small and would essentially correspond to the opening cross-section of the gas passage opening 3.

[0033] To improve the breathing function of the pressure equalization device according to the invention, it is provided that the end face 6 and the gas-permeable membrane 7 are arranged adjacent to each other in the flow direction 2 at a distance 15. This significantly increases the functional area 10 of the membrane 7 compared to the cross-sectional area through the gas passage opening 3 and improves the breathing function of the pressure equalization device.

[0034] To maximize the functional area 10, its first outer diameter 9 is designed to essentially correspond to the second outer diameter 13 of the sealing lip 12. In the illustrated embodiment, the ratio of the first outer diameter 9 to the second outer diameter 13 is essentially 1. This ensures that the interior space 18 of the cage 1 is utilized to its maximum extent by both the diaphragm 7 and the pressure relief valve 8. The outer diameters 9 and 13 each extend almost to the inner boundary of the interior space 18.

[0035] Such maximum utilization of the interior space 18 by means of the largest possible outer diameters 9, 13 is particularly advantageous when the pressure equalization device is small overall and has a small outer diameter. For good performance characteristics with regard to both the breathing function and the emergency degassing rates, the largest possible outer diameters 9, 13, relative to the size of the interior space 18, are of particular advantage.

[0036] The membrane 7 is assigned the overpressure valve 8, which is designed as burst protection, in a functionally parallel circuit, whereby the membrane 7 and the overpressure valve 8 together spatially separate the inner 4 and outer 5 from each other.

[0037] The inner diameter 11 of the pressure relief valve 8 seals the gas passage opening 3 on its outer circumference to prevent a short circuit in this area. During intended use, in normal operation, air exchange between the inner 4 and outer 5 takes place exclusively through the functional surface 10 of the diaphragm 7.

[0038] The pressure relief valve 8 comprises the sealing lip 12 with the second outer diameter 13, the sealing lip 12 contacting the sealing surface 14 of the cage 1 under elastic preload to seal. For emergency degassing of the inner surface 4, the sealing lip 12 lifts away from the sealing surface 14. Following pressure equalization, the sealing lip 12 of the pressure relief valve 8, which is formed by the convexly curved shield 16 made of rubber-elastic sealing material, again seals against the sealing surface 14.

Claims

[1] Pressure equalization device comprising a grid-shaped cage (1) with a gas passage opening (3) through which gas can flow in the direction of flow (2), which connects an inner (4) and an outer (5) of the pressure equalization device in a flow-conducting manner, wherein the gas passage opening (3) has an end face (6) facing the outer (5) which is covered by a gas-permeable membrane (7), wherein the membrane (7) is associated with a pressure relief valve (8) designed as burst protection in a functionally parallel circuit, wherein the membrane (7) and the pressure relief valve (8) together spatially separate the inner (4) and outer (5) from each other, wherein the membrane (7) has a circular functional surface (10) which is bounded by a first outer diameter (9), wherein the pressure relief valve (8) is designed in an annular shape, with an inner diameter (11),which seals around the gas passage opening (3) on its outer circumference and a sealing lip (12) with a second outer diameter (13) which seals against a sealing surface (14) of the cage (1) under elastic preload, wherein the sealing lip (12) can be lifted from the sealing surface (14) and brought into an open position for emergency degassing of the inner surface (4) and for providing a flow-conducting connection between the inner surface (4) and the outer surface (5), and wherein the end face (6) and the membrane (7) are arranged adjacent to each other in the flow direction (2) at a distance (15), , characterized by , that the ratio of the first outer diameter (9) of the functional surface (10) and the second outer diameter (13) of the sealing lip (12) is 0.9 to 1.

1. [2] Pressure equalization device according to claim 1, characterized by, that the pressure relief valve (8) is designed as a convexly protruding shield (16) towards the outside (5) and is made of a rubber-elastic sealing material. [3] Housing comprising a pressure equalization device according to claim 1 or 2.

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