Pressure-equalizing device for a housing, a housing having the pressure-equalizing device, and a method for producing the pressure-equalizing device
Patent Information
- Application Number
- EP2023758596
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-23
- Filing Date
- 2023-08-17
- Publication Date
- 2025-07-30
Smart Images
Figure 1.1
Abstract
Description
[0001] Pressure compensation device for a housing, a housing with the pressure compensation device and a manufacturing method of the pressure compensation device
[0002] 1. Field of the invention
[0003] The present invention relates to a pressure compensation device for a housing, for example a battery housing, a housing with the pressure compensation device and a manufacturing method of the pressure compensation device.
[0004] 2, Background of the invention
[0005] Pressure equalization devices are required, for example, in the drive batteries of electric vehicles, whereby the pressure equalization devices must fulfill various functionalities. On the one hand, continuous ventilation and venting are required due to temperature fluctuations during operation. Furthermore, intermittent venting must be possible to prevent damage. This functionality plays a particularly important role in the event of an accident. Finally, tightness requirements, electrical insulation, protection against misuse, and the like are frequently desired criteria. In principle, such pressure equalization devices for housings are known to those skilled in the art in a variety of different designs.
[0006] EP 3 385 584 A1 describes a pressure compensation device for a housing, wherein the pressure compensation device comprises an inner side, an outer side, and a grid-shaped cage with a gas passage opening. The gas passage opening connects the inner side and the outer side in a flow-conducting manner as required and is delimited in the direction of its permeability by an inner and an outer edge. The gas passage opening is further covered by a gas-permeable membrane. The membrane is designed as a nonwoven composite part and comprises at least one nonwoven layer.
[0007] DE 11 2019 005 328 T5 describes an alternative ventilation component. This is intended to be attached to a housing at a ventilation opening. The ventilation component comprises a gas-permeable membrane, a ventilation valve, and a structural element. The structural element has an interior space and a first ventilation path and / or a second ventilation path. The interior space is a space that accommodates the gas-permeable membrane and / or the ventilation valve. The first ventilation path allows the interior space to communicate with an exterior space of the ventilation component. The first ventilation path has a first inner opening and a first outer opening, and the first inner opening is directed toward the first outer opening. The first inner opening and the first outer opening lie along a plane parallel to an outer surface of the housing.The second ventilation path has a second inner opening and a second outer opening, and the second inner opening is present without being directed toward the second outer opening.
[0008] Another device for pressure equalization in a housing is described in DE 10 2017 214 754 A1. To provide a device for equalizing the internal pressure of a housing, in particular a battery housing for a motor vehicle, with the ambient pressure of the housing, which integrates the functions of pressure equalization during normal operation and emergency degassing in one component, the device comprises a pressure equalization element. The pressure equalization element comprises at least one element body and a membrane arranged on the element body. The device comprises a connecting element for airtightly connecting the pressure equalization element to the housing.The element body has an elasticity due to which, when an internal pressure is present which is lower than a limit pressure, the element body rests hermetically on the connecting element and, when an internal pressure is present which is greater than the limit pressure, the element body releases an opening between the element body and the connecting element for the exchange of gas.
[0009] A pressure equalization device comprising a mounting seat and a lid, wherein a receiving cavity is formed between the mounting seat and the lid, is discussed in US 2021 / 0367283 A1. The pressure equalization device may also comprise a separating element, wherein the separating element divides the receiving cavity into a first and a second receiving cavity. The separating element may also comprise a support portion and an elastic portion, wherein the support portion is disposed on the elastic portion and has a vent hole capable of fluidly connecting the receiving cavities. The elastic portion is elastically deformable to move the support portion relative to the lid. The pressure equalization device may also comprise a breathable film disposed on the support portion and covering the vent hole, which is movable when the support portion moves.
[0010] Finally, WO 2018 / 183804 A1 describes a vent assembly having a housing defining a cavity, a first end, a second end, and a coupling structure toward the second end. A mounting surface is positioned between the first end and the second end within the cavity and defines a valve opening and a vent opening. A vent is coupled to the mounting surface via the vent opening. Furthermore, an umbrella valve is sealingly disposed on the mounting surface over a valve opening.
[0011] A disadvantage of these known arrangements is the number of individual components and the mounting method of the emergency venting element. Due to the design of the known pressure compensation devices, a correct positioning of the individual components is often required during assembly, which complicates the automated manufacturing process of the pressure compensation device.
[0012] The object of the present invention is therefore to provide an alternative design for a pressure compensation device that is optimized, in particular, with regard to manufacture and assembly. Likewise, it is an object of the present invention to provide a corresponding manufacturing or assembly method for the pressure compensation device.
[0013] 3. Summary of the invention The above object is achieved by a pressure compensation device for a housing according to independent patent claim 1, a housing with the pressure compensation device according to patent claim 13 and a manufacturing method of a pressure compensation device according to independent patent claim 14. Advantageous embodiments and further developments emerge from the following description, the drawings and the appended patent claims.
[0014] A pressure compensation device according to the invention for a housing comprises: a hollow cylindrical lower part, which comprises a fastening region for fastening to the housing on the radial outside at a first axial end and a connecting region at a second axial end, an upper part with a cylindrical wall and a base, which engages with the connecting region at the second axial end of the lower part, wherein the hollow cylindrical lower part has a radially inwardly projecting, circumferential projection which defines a central through-opening and, on a side facing the second axial end, has a first, preferably annular, clamping structure, in particular a first annular groove, as well as a plurality of annularly arranged passages between the central through-opening and the first clamping structure, and the upper part comprises a second clamping structure protruding from the base in the axial direction,which is arranged in particular in a ring shape and / or has a second groove and preferably runs in the axial direction parallel to the cylindrical wall, wherein a gas-permeable membrane covers the central through-opening and an elastic sealing component with a fastening region is arranged between the first clamping structure of the lower part and the second clamping structure of the upper part and extends with a sealing region radially inwardly in the direction of the central through-opening and seals the plurality of passages, so that a ventilation and venting path runs via the central through-opening and the gas-permeable membrane and an emergency venting path runs via the plurality of passages and the elastic sealing component.
[0015] The pressure compensation device according to the invention is described below, firstly with reference to the assembly and then when used in a housing, in particular a battery housing, such as a drive battery for an electric vehicle.
[0016] The pressure equalization device consists of four elements: the base, the top or cover, the gas-permeable membrane located in the venting and exhaust passages, and the elastic sealing component, which opens the emergency venting passage when necessary.
[0017] The lower part is hollow-cylindrical and has a fastening area at the first axial end in a known manner for fastening to the housing, in particular for fastening in an opening of the housing. For example, an internal thread is provided in the opening of the housing. In this case, the fastening area therefore includes a matching external thread.
[0018] A radially inwardly projecting, circumferential protrusion is located inside the hollow cylindrical base. This serves to form the ventilation and venting paths, as well as the emergency venting path. The conventional ventilation and venting paths run through the central opening defined by the inwardly projecting, circumferential protrusion. This central opening is sealed with the gas-permeable membrane, allowing a gas, such as air, to flow through the membrane, but preferably preventing contaminants or moisture from entering the housing, and preferably preventing liquid from escaping from the housing.
[0019] To further provide an emergency venting path, the inwardly projecting, circumferential projection has a plurality of annularly arranged passages. Viewed from above, this results in a structure of the inwardly projecting, circumferential projection consisting of a radially outer and a radially inner ring, which are connected by a plurality of connecting webs. The radially inner ring defines the central passage opening, and the radially outer ring is attached to the inner wall of the hollow cylindrical lower part. The plurality of annularly arranged passages are thus present between the connecting webs that connect the two rings.
[0020] To seal the emergency venting path during conventional operation of the pressure compensation device, the elastic sealing component is provided. However, this is not attached adjacent to the central through-opening as in the prior art, but adjacent to the inner wall of the hollow cylindrical lower part. For this purpose, the radially inwardly projecting, circumferential projection has the first, preferably annular clamping structure, in particular the first annular groove, on the side facing the second axial end. Thus, the first clamping structure is formed in or on the radially outer ring of the radially inwardly projecting projection.
[0021] The elastic sealing component is secured in the axial direction via the upper part, which, when the pressure compensation device is assembled, engages with the connecting area of the lower part. The basic shape of the connecting area is annular, for example, in the form of a circumferentially closed wall.
[0022] The upper part is shaped like a cylinder closed on one side. Thus, the upper part comprises a cylindrical wall that is closed on one side by a base. The base can be completely closed or have a plurality of openings to further facilitate gas exchange between the interior of the pressure compensation device and the outside.
[0023] The radial inner side of the cylindrical wall has, for example, an annular locking feature that, when the pressure compensation device is assembled, engages with corresponding locking features in the connection area of the lower part. For example, the annular locking feature is a circumferential groove on the inner side of the cylindrical wall. This fixes the upper and lower parts to each other in the axial direction. In particular, the upper and lower parts can no longer be separated from each other in the axial direction without causing damage.
[0024] In order to ensure a flow path between the interior of the pressure compensation device and the outside, the connecting region of the lower part, when designed as a circumferential wall, preferably has alternating radially outwardly projecting and radially inwardly set-back regions. In the radially outwardly projecting regions, locking features are also present radially on the outside. Thus, in the assembled state of the pressure compensation device, the upper part engages with the connecting region at the second axial end of the lower part, in particular via the locking features. The flow path from the interior of the pressure compensation device therefore runs between the inside of the cylindrical outer wall of the upper part and the radially inwardly set-back regions in the connecting region.Instead of the radially inwardly set back regions, through-holes, openings, or axially extending recesses could also be provided in the connecting region of the lower part to provide the flow path. The second clamping structure for the elastic sealing component is provided radially inward from the cylindrical wall of the upper part. This extends in the axial direction from the bottom of the upper part, preferably parallel to the cylindrical wall of the upper part, is arranged in particular in a ring shape and / or has in particular the second groove at its axial end facing the lower part. In the assembled state of the pressure compensation device, the elastic sealing component is therefore clamped between the first clamping structure, preferably the first groove, and the second clamping structure, preferably the second groove.
[0025] To ensure that the second clamping structure for the elastic sealing component does not block the flow path from the interior of the pressure compensation device to the outside and vice versa, a plurality of apertures, openings, or the like are provided in the second clamping structure. Thus, the second clamping structure can also consist of a plurality of axial projections arranged in a ring shape, each of which has the second groove. This will become clear later, particularly in the detailed description of the preferred embodiments.
[0026] As a result, in the assembled state of the pressure compensation device, the elastic sealing component is arranged or clamped with the fastening region between the first and second clamping structures. Since the fastening region is located adjacent to the inside of the hollow cylindrical lower part, the sealing region of the elastic sealing component extends radially inward toward the central through-opening. To prevent the elastic sealing component from covering the central through-opening, it has a corresponding opening in the center. Thus, the elastic sealing component is essentially annular in the sealing region when viewed from above.Due to this construction, in the assembled state of the pressure compensation device, the elastic sealing component seals the plurality of passages adjacent to the central through-opening on the radially inner ring of the radially inwardly projecting, circumferential projection of the lower part, but without blocking the central through-opening.
[0027] Due to this inventive design, the conventional ventilation and venting path runs centrally via the central through-opening and the gas-permeable membrane, radially outward through the second clamping structure of the upper part, and between the cylindrical wall of the upper part and the radially inwardly recessed region of the wall in the connecting area of the lower part. This path allows a gas, such as air, to flow from the interior of the housing to the outside and vice versa.
[0028] Should the pressure inside the housing rise unexpectedly due to an extraordinary event, such as an accident, the increased airflow further deforms the elastic sealing component, creating a gap between the elastic sealing component and the base, particularly adjacent to the central through-hole. However, due to the specific arrangement of the elastic sealing component, venting from the housing is only possible via the elastic sealing component. Any inflow of gas, such as air, from the outside to the inside occurs exclusively via the gas-permeable membrane and the central through-hole.
[0029] One advantage of the pressure compensation device according to the invention is that the clamp fastening of the elastic sealing component allows for quick and easy assembly, which simplifies manufacturing. Furthermore, the required force with which the elastic sealing component is held in place can be easily adjusted. Furthermore, compensation for manufacturing tolerances is possible, which further simplifies the manufacturing process.
[0030] A further advantage is that the design of the pressure equalization device and the connection between the upper and lower sections provide special protection for the gas-permeable membrane thanks to the openings on the sides. This makes it difficult for moisture to penetrate the pressure equalization device, for example. This is especially true if the bottom of the upper section is completely closed.
[0031] In a preferred embodiment of the pressure compensation device, the radially inwardly projecting, circumferential projection adjacent to the central through-opening is dome-shaped in the direction of the second axial end, so that the gas-permeable membrane and the elastic sealing component are arranged at different axial heights and the sealing region of the elastic sealing component at least partially abuts the dome-shaped configuration. In other words, and with respect to the presence of the radially inner ring and the radially outer ring, the radially inner ring and the radially outer ring are arranged spaced apart from one another in the axial direction. The radially inner ring is arranged closer to the second axial end in the axial direction than the radially outer ring.However, it should be noted that the radially inner ring is positioned at an axial height below the second axial end defined by the wall of the connecting structure. Otherwise, the bottom of the upper part, when assembled, would rest on the gas-permeable membrane located on the central through-hole, potentially impeding its proper functioning.
[0032] Furthermore, the radially outer ring and the connecting webs defining the plurality of passages can be arranged at least partially in the same plane. In this case, the dome shape results, for example, from a cone or conical structure projecting conically toward the second axial end, which begins at the radially inner side of the connecting webs and ends in a plateau that is part of the radially inner ring and to which the gas-permeable membrane is attached. The conical cone or conical structure has the larger diameter adjacent to the connecting webs, so that the diameter at the plateau is smaller.
[0033] In a first particularly preferred alternative, the outer circumference of the conical structure tapers continuously from the area adjacent to the connecting webs toward the plateau. In this case, in particular, the circumferential elastic sealing component forms a radially inward seal against the dome or conical structure located coaxially in the lower part. Due to the conical structure, the seal achieved by the elastic sealing component is further improved, and the inflow of gas, such as air, into the interior of the housing via the plurality of passages is particularly effectively prevented.
[0034] In a second, likewise preferred alternative, the radially inwardly projecting, circumferential projection has a step in the region of the dome-shaped configuration, on which the sealing area of the elastic sealing component rests at least partially. Thus, the outer circumference does not taper continuously, but rather has the step. This also effectively prevents the inflow of gas, such as air, into the interior of the housing via the plurality of passages.
[0035] Furthermore, it is advantageous that a plurality of connecting webs arranged in a star shape are present in the central through-opening. Due to the connecting webs in the central through-opening, i.e., inside the radially inner ring of the radially inwardly projecting, circumferential projection, sudden loading of the gas-permeable membrane is mitigated. Furthermore, due to its arrangement between the upper and lower parts, the gas-permeable membrane is protected against mechanical damage, misuse, and the like even before the assembled pressure compensation device is installed in the housing opening.
[0036] The above-described effect of the connecting webs also applies to the connecting webs adjacent to or below the elastic sealing component, which define the plurality of annularly arranged passages. This effectively prevents sudden loading of both the gas-permeable membrane and the elastic sealing component in the event of an abnormal event.
[0037] In a preferred embodiment of the pressure compensation device, the elastic sealing component has a T-shaped fastening area, so that the sealing area extends perpendicularly from the T-shaped fastening area. This design in particular can be clamped particularly advantageously between the first clamping structure of the lower part and the second clamping structure of the upper part. In addition, due to the T-shaped design, possible manufacturing tolerances of the upper part and the lower part can be effectively compensated. Also, the elastic sealing component is designed, particularly due to the T-shaped fastening area, so that it can be used on both sides. As a result, correct positional feeding is not necessary. This simplifies the automation of the production and assembly of the pressure compensation device.
[0038] Furthermore, according to a first alternative, it is preferred that the elastic sealing component has: a sealing region that tapers radially inwards and / or at least one annular projection that projects axially upwards or downwards or at least one annular sealing lip that projects axially upwards or downwards on a radially inner side of the sealing region, preferably three annular projections or sealing lips and particularly preferably three annular projections or sealing lips that project axially upwards and three annular projections or sealing lips. In the initial state, the elastic sealing component with the sealing region that tapers radially inwards represents a straight and symmetrically manufactured elastic sealing component. In this case, the radially inner region of the sealing region, i.e. the region with the smallest thickness, is deformed when used in the pressure compensation device such that it preferably rests against the dome-shaped region.The increased preload thus generated ensures further improved sealing of the majority of through openings during normal operation.
[0039] Instead of the tapered design of the sealing area, or in addition thereto, the elastic sealing component has at least one annular projection or an annular sealing lip on at least one side, preferably three annular structures or projections or sealing lips on each side. It is precisely this design with the at least one annular projection or the at least one annular sealing lip that further increases the flexibility of the elastic sealing component and thus further improves the seal, especially in the dome-shaped region of the radially inwardly projecting, circumferential projection of the lower part.
[0040] According to a second alternative, it is preferred that the elastic sealing component has a curved cross-section on the radial inside, preferably inverted U-shaped. The curved course and thus in particular the inverted U-shape is present adjacent to the radial inside of the sealing region of the elastic sealing component. The term inverted U-shaped refers to a curved course which, in the installed state of the elastic sealing component, runs from the radial inside towards the radial outside, initially in the direction of the second axial end of the lower part up to an apex and back to the original height, preferably to the height of the fastening region. With this special type of configuration, in particular in combination with a step present in the dome-shaped region, as explained above, a further increased elastic prestress can be generated. The sealing behavior is thus further improved.The disadvantage, however, is that this design in particular has to be supplied in the correct position, which makes the manufacture or assembly of the pressure compensation device more complex.
[0041] Advantageously, the upper part and / or the lower part is made of thermoplastic material.
[0042] This allows the pressure compensation device to be specifically adapted to the temperature requirements and chemical resistance required for the application. For example, the materials used for the upper and / or lower sections are PP-GF, PBT, PA6, or PA66.
[0043] Furthermore, the pressure compensation device is preferably designed such that the gas-permeable membrane is attached to the radially inwardly projecting, circumferential projection adjacent to the central through-opening by means of adhesive bonding, welding, or integral overmolding. This allows the pressure compensation device to be adapted to the specific application and the gas-permeable membrane used. For example, the gas-permeable membrane can be a self-adhesive membrane film for the ventilation and de-aeration of housings. Pressure equalization or gas passage takes place via an adhesive-free zone. Alternatively, the gas-permeable membrane can also be welded. As an alternative to these attachment methods, it is also possible to overmolde the gas-permeable membrane during the manufacture of the lower part, which is explained below in the context of the manufacturing processes.
[0044] In a further advantageous embodiment, the elastic sealing component consists of silicone, rubber, or a thermoplastic elastomer. In addition, the pressure compensation device preferably comprises a seal such as an O-ring on the radial outside, in particular adjacent to a radially outwardly projecting flange between the fastening region and the connection region. In both cases, i.e., for both the elastic sealing component and the seal, in particular the O-ring, it is important to use a material, such as an elastomer, that can withstand the respective temperature requirements and has the desired chemical resistance for the respective area of use. The pressure compensation device can thus be further adapted to the desired application.With regard to the required hardness for the elastic sealing component and / or the seal, in particular the O-ring, these can have a similar hardness, for example in the range between 40 and 70 Shore A. In particular, the design of the elastic sealing component with the curved profile preferably has a higher hardness of up to 80 Shore A.
[0045] Finally, it is advantageous that the mounting area of the pressure compensation device is designed as a thread, bayonet lock, snap-in structure, or adhesive structure. Due to this fundamentally freely configurable mounting area, the mounting of the pressure compensation device in the housing can be implemented flexibly and adapted specifically to the desired application.
[0046] A housing according to the invention, preferably a battery housing, with an opening has a pressure compensation device according to the invention arranged in the opening. Since the housing comprises the pressure compensation device according to the invention, reference is made to the above statements with regard to the resulting technical effects and advantages in order to avoid repetition.
[0047] A manufacturing method of a pressure compensation device according to the invention comprises the following steps: injection molding of a hollow cylindrical lower part, which comprises a fastening region for fastening to the housing on the radial outside at a first axial end and a connecting region at a second axial end, wherein the hollow cylindrical lower part has a radially inwardly projecting, circumferential projection which defines a central through-opening and, on a side facing the second axial end, has a first, preferably annular, clamping structure, in particular a first annular groove, as well as a plurality of annularly arranged passages between the central through-opening and the first clamping structure, and injection molding of an upper part with a cylindrical wall and a base, which comprises a second clamping structure protruding from the base in the axial direction,which is arranged in particular in a ring shape and / or has a second groove and preferably runs in the axial direction parallel to the cylindrical wall, fastening a gas-permeable membrane on the lower part, arranging an elastic sealing component with a fastening region in the first clamping structure of the lower part, wherein a sealing region of the elastic sealing component extends radially inwardly towards the central through-opening, and arranging the upper part on the lower part such that the upper part engages with the connecting region at the second axial end of the lower part and the elastic sealing component with the fastening region is arranged between the first clamping structure of the lower part and the second clamping structure of the upper part, wherein the elastic sealing component seals the plurality of passages in such a way,that a ventilation path runs through the central through-opening and the gas-permeable membrane, and an emergency venting path runs through the plurality of passages and the elastic sealing component. The pressure compensation device according to the invention is manufactured using the manufacturing method according to the invention. Therefore, with regard to the resulting technical effects and the associated advantages, reference is again made to the above statements regarding the pressure compensation device according to the invention in order to avoid repetition.
[0048] In a preferred embodiment of the manufacturing method, the step of attaching the gas-permeable membrane to the lower part comprises overmolding the gas-permeable membrane during the injection molding of the lower part. This further simplifies the manufacturing method, as a separate step for attaching the gas-permeable membrane to the lower part is eliminated.
[0049] 4, Brief summary of the drawings
[0050] The present invention is described in detail below with reference to the drawings. Like reference numerals in the drawings denote like components and / or elements. They show:
[0051] Figure 1 is an exploded view of an embodiment of a pressure compensation device according to the invention with a first embodiment of an elastic sealing component,
[0052] Figure 2 is a side view of the embodiment according to Fig. 1 in the assembled state,
[0053] Figure 3 is a sectional view of the embodiment according to Figure 1 with the first embodiment of the elastic sealing component,
[0054] Figure 4 is a perspective view of the lower part according to the embodiment of Fig. 1 from below,
[0055] Figure 5 is a plan view of the lower part according to Fig. 4,
[0056] Figure 6 is an enlarged perspective view of a part of the connecting area of the lower part according to Fig. 4, Figure 7 is a perspective view of the upper part according to the embodiment according to Fig. 1,
[0057] Figure 8 is a perspective view of the first embodiment of the elastic sealing component,
[0058] Figure 9 is a sectional view of the elastic sealing component according to Fig.8,
[0059] Figure 10 is a sectional view of the pressure compensation device with a second embodiment of the elastic sealing component,
[0060] Figure 11 is a perspective view of the second embodiment of the elastic sealing component,
[0061] Figure 12 is a sectional view of the elastic sealing component according to Fig.11,
[0062] Figure 13 is a sectional view of the pressure compensation device with a third embodiment of the elastic sealing component,
[0063] Figure 14 is a perspective view of the third embodiment of the elastic sealing component,
[0064] Figure 15 is a sectional view of the elastic sealing component according to Fig.14 and
[0065] Figure 16 is a flow chart of an embodiment of a manufacturing method of the pressure compensation device according to the invention.
[0066] 5. Detailed Description of the Preferred Embodiments An embodiment of a pressure compensation device 1 is shown in Figure 1 in an exploded view, in Figure 2 in the assembled state, and in Figure 3 in a sectional view. The pressure compensation device 1 is used in a housing, for example, a battery housing of a drive battery of an electric vehicle.
[0067] As can be seen in particular from Figure 1, the pressure compensation device 1 basically comprises a lower part 10, a gas-permeable membrane 50, an upper part 60 and an elastic sealing component 80. In the present embodiment, an O-ring 90 is further provided as a seal for sealing during fastening in an opening of the housing (not shown).
[0068] The individual components of the pressure compensation device 1 are discussed individually below. Therefore, we will first examine the lower part 10, which is shown in Figures 4-6.
[0069] The lower part 10 is hollow-cylindrical and has a fastening area 14 for attachment to the housing at a first axial end 12. In the present case, the fastening area 14 has an external thread 16.
[0070] A connecting region 20 is provided at a second axial end 18. Due to the hollow-cylindrical design of the lower part 10, the connecting region 20 is formed, in particular, by an annular wall, wherein radially outwardly projecting regions 22 are arranged in the connecting region 20, alternating with radially inwardly recessed regions 26. The radially outwardly projecting regions 22 additionally have a locking feature 24 that extends radially outward. The advantage of this design and its mode of operation will be explained later in the discussion of the assembled pressure compensation device 1.
[0071] For the sake of completeness, it should be noted that instead of the radially inwardly recessed regions 26, openings or through-holes could also be provided at these locations. In this case, the connecting region 20 would consist of axial projections representing the radially outwardly projecting region 22 and having the radially outwardly extending locking feature 24. A radially outwardly projecting flange 28 is provided between the fastening region 14 and the connecting region 20. In the embodiment shown, this is hexagonal and has rounded corners. As a result, the flange 28 provides a drive feature for screwing the pressure compensation device 1 via the external thread 16 of the fastening region 14 into the opening in the housing, which in this case comprises a corresponding internal thread.
[0072] To provide a suitable seal for the pressure compensation device 1 in the opening of the housing, the O-ring 90 is provided as a seal. As can be seen in Figures 1 to 3, this is arranged in the mounting area 14 adjacent to the flange 28.
[0073] Furthermore, a radially inwardly projecting, circumferential projection 30 is provided inside the lower part 10. This serves to form the ventilation and venting path as well as the emergency venting path. Both will be explained later when using the pressure equalization device 1. The radially inwardly projecting, circumferential projection 30 consists, viewed from above, of a radially outer ring 32, connecting webs 34 extending radially inward therefrom, and a radially inner ring 36. Corresponding annularly arranged passages 38 are therefore provided between the connecting webs 34. These serve for emergency venting, which will also be explained later. Furthermore, due to this structure, a central through-opening 44 is provided, which is defined in particular by the radially inner ring 36 of the radially inwardly projecting, circumferential projection 30.
[0074] In the present embodiment, the radially inner ring 36 is dome-shaped with a conical structure 40. The conical structure 40 extends in a continuously tapered manner from an area adjacent to the connecting webs 34 toward a plateau. This is particularly evident in the sectional view in Figure 3. Furthermore, star-shaped connecting webs 46 are provided inside the central through-opening 44. These are spaced axially from the plateau in the direction of the first axial end 12 of the lower part 10 and connected to the plateau via a circumferential wall structure. The significance of these connecting webs 46 and the connecting webs 34 on the radially outer ring 32 will be explained later.
[0075] The gas-permeable membrane 50, which covers the central through-opening 44, is arranged on the plateau, i.e., on the radially inner ring 36. With regard to the axial height of the plateau, it should be noted that it is arranged below the second axial end 18, which is defined by the connecting region 20. Otherwise, there would be a risk that the upper part 60 would later impede the proper functioning of the gas-permeable membrane 50 in the assembled state.
[0076] Finally, it should be noted that the radially outer ring 32 of the radially inwardly projecting, circumferential projection 30 has a first annular clamping structure 47 in the form of a first annular groove 48, which is formed on the side facing the second axial end 18.
[0077] Referring now to Figure 7, the structure of the upper part 60 is explained. This consists of a cylindrical wall 62 and a base 64. Furthermore, a second clamping structure 66 is provided, which protrudes axially from the base 64 and is arranged in a ring shape. The second clamping structure 66 has a second groove 70, which accordingly also runs in a ring shape. In the illustrated embodiment, the second clamping structure 66 also extends axially parallel to the cylindrical wall 62.
[0078] A circumferential locking feature 72 is also provided on the radial inner side of the cylindrical wall 62. In the assembled state, this engages with the locking features 24 in the connecting area 20 of the lower part 10. For example, the locking feature 72 is a circumferential groove in the cylindrical wall 62. In particular, this secures the position in the axial direction, so that non-destructive separation of the upper part 60 and the lower part 10 is no longer possible.
[0079] Referring again to the upper part 60, the second clamping structure 66 is provided with a plurality of openings or recesses 67, resulting in a plurality of webs 68. Instead of the openings or recesses 67, openings such as bores or the like could also be provided in the second clamping structure 66. These openings, openings, or recesses 67 are necessary to ensure a flow path from the interior of the pressure compensation device 1 to the outside and vice versa. This applies analogously to the radially inwardly set-back regions 26 in the connecting region 20 of the lower part 10. Here, instead of the radially inwardly set-back region 26, openings or recesses could also be provided to ensure the flow path from and into the interior of the pressure compensation device 1. In the illustrated embodiment of the upper part 60, the base 64 is closed.Alternatively, one or more openings can be provided in the area of the base 64 of the upper part 60 to further support ventilation. However, a disadvantage of this is that moisture can more easily penetrate the interior of the pressure equalization device 1 compared to a solid base 64.
[0080] Figures 8 and 9 show a first embodiment of the elastic sealing component 80. This consists of a radially outer T-shaped fastening region 82 and a radially inwardly extending sealing region 84. To ensure that the sealing component 80 does not cover the central passage opening 44 and / or the gas-permeable membrane 50 in the assembled state of the pressure compensation device 1 and impede their function, the elastic sealing component 80 has an opening in the center. The radially inner side of the sealing region 84 therefore preferably bears against the radially inner ring 36 and in particular the conical structure 40 of the radially inwardly projecting, circumferential projection 30, thus sealing the passages 38.
[0081] An advantage of this embodiment of the elastic sealing component 80 is that it is symmetrical. Thus, correct orientation during assembly is not important; rather, the elastic sealing component can be inserted in any orientation and still fulfill its function.
[0082] As can be seen particularly from Figure 9, the sealing region 84 tapers from the radially outer end toward the radially inner end. This is preferred because the elastic sealing component 80, with the sealing region 84, rests against the dome-shaped or conical structure 40 in the assembled state, as can be seen from Figure 3 and explained above. In particular, the radially inner end of the sealing region 84 is bent toward the second axial end 18. This creates a corresponding preload, so that the elastic sealing component 80 effectively seals the passages 38.
[0083] When using the pressure equalization device 1, the conventional ventilation and venting path thus runs via the central through-opening 44 and the gas-permeable membrane 50, radially outward through the second clamping structure 66 of the upper part 60, and between the cylindrical wall 62 of the upper part 60 and the radially inwardly recessed region 26 in the connecting region 20 of the lower part 10. This path allows a gas, such as air, to flow from the interior of the housing to the outside and vice versa. An advantage of this design is that the gas-permeable membrane 50 is particularly protected from moisture and contaminants. Furthermore, assembly is simplified due to the small number of components and the symmetrically designed elastic sealing component 80.It should also be noted that, due to the fastening area 82 of the elastic sealing component 80, manufacturing-related tolerances between the upper part 60 and the lower part 10 can be better compensated for compared to the prior art, which further simplifies production.
[0084] The connecting webs 34 and 46 serve to mitigate sudden loading on the gas-permeable membrane 50 and the elastic sealing component 80. Furthermore, due to their arrangement between the upper and lower parts, the gas-permeable membrane 50, as well as the elastic sealing component 80, are protected against mechanical damage, misuse, and the like even before the assembled pressure compensation device 1 is installed in the opening of the housing.
[0085] Referring now to Figures 10-12, an alternative embodiment of the pressure compensation device 100 is shown, in which, in particular, a different embodiment of an elastic sealing component 180 is used. Otherwise, the structure of the pressure compensation device 100 with regard to the lower part 10, the gas-permeable membrane 50 and the upper part 60, as well as the O-ring 90, is identical to the first embodiment of the pressure compensation device 1. Therefore, the functionality is also the same as the first embodiment of the pressure compensation device 1.
[0086] In the second embodiment, the elastic sealing component 180 also has the fastening region 182, which is T-shaped. Likewise, the sealing region 184 is provided, which tapers from a radially outer end to a radially inner end, with an opening provided in the center for engagement with the dome-shaped region or the conical structure 40.
[0087] In contrast to the previous embodiment, however, the sealing component 180 now comprises three annular projections or sealing lips 186 on each side of the sealing region 184 adjacent to the radially inner end. These annular projections or sealing lips 186 thus extend axially from the sealing region 184. The annular projections or sealing lips 186 increase the flexibility of the elastic sealing component 180 in the sealing region 184 and, in particular, improve the preload on the conical structure 40. Thus, the sealing of the passages 38 by the elastic sealing component 180 is further improved.
[0088] Another alternative pressure equalization device 200 is shown in Figures 13-15. This configuration also corresponds to the previous embodiments in terms of its basic structure, so the differences will be discussed in particular below. The basic course of the ventilation and venting paths as well as the emergency venting path is the same as in the previous embodiments of the pressure equalization device 1; 100.
[0089] In the embodiment of the pressure compensation device 200, a sealing region 284 of an elastic sealing component 280 has a curved region 288. This is particularly formed in an inverted U-shape. Inverted U-shape here means that the profile rises from the radially inner end of the sealing region 284 toward the second axial end 18 of the lower part 10 to a peak and then descends to the initial height.
[0090] Sealing with this configuration of the elastic sealing component 280 is particularly effective when the conical structure 240 is not continuous, but rather has a step 242 on which the radially inner end of the sealing region 284 rests. This allows the preload to be further increased and an effective seal for the passages 38 to be achieved. A disadvantage of this configuration, however, is that the elastic sealing component 280 must be fed in the correct position due to the sealing region 284, even if the fastening region 282 is T-shaped, similar to the previous embodiments.
[0091] Finally, the manufacturing process of the pressure compensation device 1; 100; 200 is explained using the flow chart shown in Figure 16.
[0092] Thus, in a first step A, the hollow cylindrical lower part 10; 210 is injection-molded. As shown above, the lower part 10; 210 has a fastening region 14 for fastening to the housing on the radial outside at a first axial end 12 and a connecting region 20 at a second axial end 18. In addition, the hollow cylindrical lower part 10; 210 has a radially inwardly projecting, circumferential projection 30 which defines a central through-opening 44. Likewise, the lower part 10; 210 comprises, on a side facing the second axial end 18, a first, preferably annular clamping structure 47, in particular a first annular groove 48, as well as a plurality of annularly arranged passages 38 between the central through-opening 44 and the first clamping structure 47. The fastening region 14 is advantageously designed as a thread, bayonet lock, snap-in structure, or adhesive structure.Due to this fundamentally freely configurable fastening area 14, the fastening of the pressure compensation device 1; 100; 200 in the housing can be implemented flexibly and specifically adapted to the desired application.
[0093] In a second step B, the upper part 60 is injection-molded with the cylindrical wall 62 and the base 64, which comprises a second clamping structure 66 protruding axially from the base 64. In particular, this second clamping structure is arranged in a ring shape and comprises a second groove 70. Preferably, the second clamping structure 66 extends axially parallel to the cylindrical wall 62.
[0094] Advantageously, a thermoplastic material is used as the material for the upper part 60 and / or the lower part 10; 210. In this way, the pressure compensation device 1; 100; 200 can be specifically adapted to the temperature requirements and the required chemical resistance of the application area. For example, the materials used for the upper part 60 and / or the lower part 10; 210 are PP-GF, PBT, PA6, or PA66.
[0095] The gas-permeable membrane 50 is attached to the lower part 10; 210 in step C. The gas-permeable membrane 50 is attached, in particular, to the radially inner ring 36 of the radially inwardly projecting projection 30 of the lower part 10; 210. This can be done by gluing or welding. Thus, the gas-permeable membrane 50 can be a self-adhesive membrane film for the ventilation of housings. Pressure equalization or gas passage takes place via an adhesive-free zone. Alternatively, the gas-permeable membrane can also be welded. Furthermore, it is also possible to overmold the gas-permeable membrane during the production of the lower part 10; 210. This further simplifies the manufacturing process, since a separate step for attaching the gas-permeable membrane 50 to the lower part 10; 210 and, in particular, to the radially inwardly projecting projection 30 is eliminated.
[0096] In step D, the elastic sealing component 80; 180; 280 is arranged with a fastening region 82; 182; 282 in the first, preferably annular, clamping structure 47, in particular the first annular groove 48, of the lower part 10; 210. The sealing region 84; 184; 284 of the elastic sealing component 80; 180; 280 extends radially inward toward the central through-opening 44.
[0097] In step E, the upper part 60 is arranged on the lower part 10 such that the upper part 60 engages the connecting region 20 at the second axial end 18 of the lower part 10; 210, and the elastic sealing component 80; 180; 280 with the fastening region 82; 182; 282 is arranged between the first clamping structure 47 of the lower part 10 and the second clamping structure 66 of the upper part 60. The elastic sealing component 80; 180; 280 thereby seals the plurality of passages 38 such that a ventilation path runs via the central through-opening 44 and the gas-permeable membrane 50, and an emergency ventilation path runs via the plurality of passages 38 and the elastic sealing component 80; 180; 280.
[0098] The elastic sealing component 80; 180; 280 is preferably made of silicone, rubber, or a thermoplastic elastomer. Furthermore, the pressure compensation device 1; 100; 200 preferably comprises a seal such as an O-ring on the radial outside, in particular adjacent to a radially outwardly projecting flange 28 between the fastening region 14 and the connecting region 20.
[0099] In both cases, i.e., for both the elastic sealing component 80; 180; 280 and the seal, in particular the O-ring 90, it is important to use a material, such as an elastomer, that can withstand the respective temperature requirements and has the desired chemical resistance for the respective area of application. Thus, the pressure compensation device 1; 100; 200 can be further adapted to the desired application. With regard to the required hardness for the elastic sealing component 80; 180; 280 and / or the seal, in particular the O-ring 90, these can have a similar hardness, for example in the range between 40 and 70 Shore A. In particular, the design of the elastic sealing component 280 with the curved profile preferably has a higher hardness of up to 80 Shore A.
[0100] 6. List of reference symbols 1 Pressure compensation device (1st embodiment)
[0101] 10 Lower part
[0102] 12 first axial end
[0103] 14 Mounting area
[0104] 16 External thread in the fastening area 14
[0105] 18 second axial end
[0106] 20 Connection area
[0107] 22 radially outwardly projecting area
[0108] 24 locking feature
[0109] 26 radially inwardly recessed area
[0110] 28 flange
[0111] 30 radially inwardly projecting, circumferential projection
[0112] 32 radial outer ring
[0113] 34 connecting webs on the radial outer ring 32
[0114] 36 radial inner ring
[0115] 38 passage
[0116] 40 conical structure
[0117] 44 central passage opening
[0118] 46 connecting bars in the central passage opening
[0119] 47 first clamping structure
[0120] 48 first annular groove
[0121] 50 gas-permeable membrane
[0122] 60 top
[0123] 62 cylindrical wall
[0124] 64 Floor
[0125] 66 second clamping structure
[0126] 67 recess
[0127] 68 bridges
[0128] 70 second groove
[0129] 72 Snap-in feature of the upper part 60 Elastic sealing component Fastening area Sealing area O-ring Pressure compensation device (2nd embodiment) Elastic sealing component Fastening area Sealing area Sealing lip in the sealing area 184 Pressure compensation device (3rd embodiment) Lower part Conical structure Step in the conical structure 240 Elastic sealing component Fastening area Sealing area Curved area in the sealing area 284
Claims
Patent claims 1. A pressure compensation device (1; 100; 200) for a housing, the pressure compensation device (1; 100; 200) comprising: a. a hollow cylindrical lower part (10; 210) which, radially outwardly at a first axial end (12), comprises a fastening region (14) for fastening to the housing and at a second axial end (18), a connecting region (20), b. an upper part (60) with a cylindrical wall (62) and a base (64), which engages with the connecting region (20) at the second axial end (18) of the lower part (10; 210), wherein c.the hollow cylindrical lower part (10; 210) has a radially inwardly projecting, circumferential projection (30) which defines a central through-opening (44) and, on a side facing the second axial end (18), has a first, preferably annular, clamping structure (47), in particular a first annular groove (48), as well as a plurality of annularly arranged passages (38) between the central through-opening (44) and the first clamping structure (47), and d. the upper part (60) comprises a second clamping structure (66) which projects in the axial direction from the base (64), which is in particular annularly arranged and / or has a second groove (70) and preferably runs in the axial direction parallel to the cylindrical wall (62), wherein e. a gas-permeable membrane (50) covers the central through-opening (44), and f.an elastic sealing component (80; 180; 280) with a fastening region (82; 182; 184) is arranged between the first clamping structure (47) of the lower part (10; 210) and the second clamping structure (66) of the upper part (60) and extends with a sealing region (84; 184; 284) radially inwardly in the direction of the central through-opening (44) and seals the plurality of passages (38), so that. g. a ventilation path runs via the central passage opening (44) and the gas-permeable membrane (50) and an emergency ventilation path runs via the plurality of passages (38) and the elastic sealing component (80; 180; 280).
2. The pressure compensation device (1; 100; 200) according to claim 1, wherein the radially inwardly projecting, circumferential projection (30) adjacent to the central through-opening (44) in the direction of the second axial end (18) is dome-shaped, so that the gas-permeable membrane (50) and the elastic sealing component (80; 180; 280) are arranged at different axial heights and the sealing region (84; 184; 284) of the elastic sealing component (80; 180; 280) bears at least partially against the dome-shaped configuration.
3. The pressure compensation device (200) according to claim 2, wherein the radially inwardly projecting, circumferential projection (30) has a step (242) in the region of the dome-shaped configuration, on which the sealing region (284) of the elastic sealing component (280) rests at least partially.
4. The pressure compensation device (1; 100; 200) according to claim 2 or 3, which has a plurality of star-shaped connecting webs (46) in the central through-opening (44).
5. The pressure equalization device (1; 100; 200) according to one of the preceding claims, wherein the elastic sealing component (80; 180; 280) has a T-shaped fastening region (82; 182; 282) such that the sealing region (84; 184; 284) extends perpendicularly from the T-shaped fastening region (82; 182; 282).
6. The pressure compensation device (1; 100; 200) according to one of the preceding claims, wherein the elastic sealing component (80; 180) comprises: a. a radially inwardly tapering sealing region (84; 184) and / or b. at least one axially upwardly or downwardly projecting annular projection (186) on a radially inner side of the sealing region (184), preferably three annular projections or sealing lips (186) and particularly preferably three axially upwardly and three axially downwardly projecting annular projections or sealing lips (186).
7. The pressure compensation device (200) according to one of claims 1 to 5, wherein the elastic sealing component (280) has a radially inwardly curved cross-section, preferably an inverted U-shape.
8. The pressure compensation device (1; 100; 200) according to one of the preceding claims, wherein the upper part (60) and / or the lower part (10; 210) consists of thermoplastic material.
9. The pressure equalization device (1; 100; 200) according to one of the preceding claims, wherein the gas-permeable membrane (50) is attached to the radially inwardly projecting, circumferential projection (30) adjacent to the central through-opening (44) by means of gluing, welding or integral overmolding.
10. The pressure equalization device (1; 100; 200) according to one of the preceding claims, wherein the elastic sealing component (80; 180; 280) consists of silicone, rubber or a thermoplastic elastomer.
11. The pressure compensation device (1; 100; 200) according to one of the preceding claims, which further comprises a radially outward seal, in particular an O-ring (90), preferably adjacent to a radially outwardly projecting flange (28) between the fastening region (14) and the connecting region (20).
12. The pressure compensation device (1; 100; 200) according to one of the preceding claims, wherein the fastening area (14) is designed as a thread, bayonet closure, locking structure or adhesive structure.
13. A housing, in particular a battery housing, with an opening in which a pressure compensation device (1; 100; 200) according to one of the preceding claims 1 to 12 is arranged. A manufacturing method for a pressure compensation device (1; 100; 200) according to one of claims 1 to 12, comprising the following steps: a. injection molding (A) of a hollow cylindrical lower part (10; 210) which comprises, radially outwardly at a first axial end (12), a fastening region (14) for fastening to the housing and, at a second axial end (18), a connecting region (20), wherein the hollow cylindrical lower part (10; 210) has a radially inwardly projecting, circumferential projection (30) which defines a central through-opening (44) and, on a side facing the second axial end (18), has a first, preferably annular, clamping structure (47), in particular a first annular groove (48), as well as a plurality of annularly arranged passages (38) between the central through-opening (44) and the first clamping structure (47), and b.Injection molding (B) of an upper part (60) with a cylindrical wall (62) and a base (64), which comprises a second clamping structure (66) protruding in the axial direction from the base (64), which is arranged in particular in a ring shape and / or has a second groove (70) and preferably runs in the axial direction parallel to the cylindrical wall (62), c. Fastening (C) a gas-permeable membrane (50) on the lower part (10; 210), d. Arranging (D) an elastic sealing component (80; 180; 280) with a fastening region (82; 182; 282) in the first clamping structure (47) of the lower part (10; 210), wherein a sealing region (82; 182; 282) of the elastic sealing component (80; 180; 280) extends radially inwardly in the direction of the central through-opening (44), and e.Arranging (E) the upper part (60) on the lower part (10; 210) such that the upper part (60) engages the connecting region (20) at the second axial end (18) of the lower part (10; 210) and the elastic sealing component (80; 180; 280) with the fastening region (82; 182; 282) is arranged between the first clamping structure (47) of the lower part (10; 210) and the second clamping structure (66) of the upper part (60), wherein the elastic sealing component (80; 180; 280) defines the plurality of passages. (38) such that a ventilation path runs through the central through-opening (44) and the gas-permeable membrane (50), and an emergency ventilation path runs through the plurality of passages (38) and the elastic sealing component (80; 180; 280). The manufacturing method according to claim 14, wherein the step of attaching (C) the gas-permeable membrane (50) to the base (10; 210) comprises overmolding the gas-permeable membrane (50) during the injection molding of the base (10; 210).