Standard metric thread pressure balance valve for waterproof and moisture-proof and air-permeable and its membrane assembly

Abstract

The utility model discloses a standard metric thread moistureproof waterproof and breathable pressure balance valve and membrane module thereof, membrane module includes waterproof and breathable membrane piece made of the hydrophobic and oleophobic modification treatment of ePTFE microporous film of the expansion polytetrafluoroethylene, the elastic composite of waterproof and breathable membrane piece and valve piece, the elastic valve piece of thin wall structure, which is provided with dynamic opening and closing gap, membrane module is arranged on the airflow channel of pressure balance valve body, waterproof and breathable membrane piece is arranged at the outside end of airflow channel and is used for blocking external liquid and dust, and valve piece is arranged at the inside end of airflow channel and is used for dynamic regulation internal air pressure balance. Through above -mentioned mode, the utility model has waterproof and breathable and pressure regulation's double function, blocks external liquid and particulate matter to enter again, and can automatic regulation ventilation according to pressure difference, control water vapor to enter battery pack from the source, effectively solve the internal and external pressure balance of power battery pack and eliminate its inside fog condensation phenomenon.

Description

Technical Field

[0001] This utility model relates to the field of waterproof and breathable materials for power battery packs, vehicle headlight protection, electrical equipment, or chemical filtration, and in particular to a standard metric threaded moisture-proof and waterproof breathable membrane assembly and a pressure balance valve. Background Technology

[0002] With the widespread application of new energy vehicles, the problem of fogging and condensation in their battery packs has gradually become prominent, becoming a technical challenge that urgently needs to be solved. Fogging and condensation are quite common in new energy vehicle battery packs.

[0003] Why does condensation form inside a power battery? Power batteries are not completely sealed; they all have a venting design. This serves two purposes: first, to allow air circulation to cool the battery; and second, to balance the air pressure inside and outside the battery. When the power battery is working normally, the temperature inside the battery pack is very high, and water vapor is heated and vaporized. After the power battery stops working, the temperature inside the battery pack drops sharply, and water vapor condenses on the inner wall of the battery pack, forming condensation. This is the battery pack's "breathing" function. Under normal circumstances, the heat generated during normal operation can remove the condensation. If the condensation persists, it is likely due to a quality problem with the battery pack itself or that the battery pack has been operating in a high-moisture environment for an extended period. Eventually, the battery pack will no longer contain condensation but rather small water droplets. This will trigger an insulation fault alarm in the electronic control system, rendering the electric vehicle unusable. If the battery pack malfunctions, it can even lead to a short circuit, fire, or explosion. Therefore, while ensuring the normal "breathing" function of the power battery pack, it is also necessary to minimize the water vapor concentration inside the battery pack to prevent condensation.

[0004] Currently, a passive approach is mostly used to handle this situation. Specifically, when condensation occurs inside the battery pack, moisture gradually condenses into water, eventually collecting at the bottom of the battery compartment and draining through the drain valve. However, as the amount of liquid increases, some liquid may seep into the battery pack, causing oxidation and rust on components. Over time, the performance of these components will gradually decline, even leading to malfunctions and frequent breakdowns. This not only affects the normal operation of new energy vehicles but also increases safety hazards and maintenance costs. In extreme cases, when the electronic control system alarms due to insulation failure, the electric vehicle will not function properly, the battery pack will also malfunction, and it may even directly cause a short circuit, fire, or explosion, seriously threatening the safety of the vehicle and its occupants.

[0005] In addition, there is a type of biodegradable film on the market used for electrical protection that is not resistant to environmental aging, such as waterproof and breathable cotton fabric, waterproof and breathable paper, waterproof and breathable PE nonwoven fabric, waterproof and breathable PP nonwoven fabric, waterproof and breathable PET nonwoven fabric, and waterproof and breathable PA (Nylon) nonwoven fabric. Although these films have a certain degree of waterproof and breathable function, their service life is relatively short. When used outdoors, their lifespan is usually only a few months; while when used indoors, their lifespan can reach 3 to 5 years. Fluorescent ultraviolet lamp exposure aging tests have shown that these materials exhibit slight embrittlement after about 48 hours, complete embrittlement after about 72 hours, and powdering after about 100 hours, with significant changes in material properties, ultimately losing their protective function. Although adding anti-UV aging agents to plastic nonwoven fabrics can extend their service life to some extent, the fundamental problem has not yet been effectively solved.

[0006] In summary, existing passive treatment methods and solutions using biodegradable films that are not resistant to environmental aging cannot fundamentally solve the condensation problem within new energy vehicle battery packs. Therefore, there is an urgent need for a technical solution that can control moisture entry into the battery pack at its source and effectively solve the condensation phenomenon. Utility Model Content

[0007] The main technical problem solved by this utility model is to provide a standard metric threaded moisture-proof, waterproof and breathable pressure balance valve and its membrane assembly that can block water vapor penetration from the source, automatically open and close due to pressure difference, and balance the internal and external air pressure.

[0008] To solve the above-mentioned technical problems, the present invention provides a waterproof and breathable membrane assembly, comprising: The waterproof and breathable membrane is made of expanded polytetrafluoroethylene (ePTFE) microporous film with surface hydrophobic and oleophobic modification treatment. It is placed on the air inlet side of the breathable channel to form a waterproof and breathable barrier. An elastic composite material is placed between the waterproof and breathable membrane and the valve plate to provide support for the opening and closing of the valve plate. The valve plate is a thin-walled, elastic valve plate with dynamic opening and closing slits. Supported by an elastic composite, it controls the opening and closing of the air permeability channel. The membrane module achieves the dual functions of waterproofing and breathability, as well as pressure regulation. It not only blocks the entry of external liquids and particles but also automatically adjusts the air permeability according to the pressure difference.

[0009] In a preferred embodiment of the present invention, the surface hydrophobic and oleophobic modification treatment includes coating the surface of the expanded polytetrafluoroethylene (ePTFE) microporous film with fluorocarbon adhesive, which, after curing, forms a hydrophobic and oleophobic expanded polytetrafluoroethylene (ePTFE) microporous film.

[0010] In a preferred embodiment of this invention, the hydrophobic and oleophobic expanded polytetrafluoroethylene (ePTFE) microporous membrane has a micropore size of 0.01–15 μm, a porosity of 50–90%, a water contact angle ≥150°, and an oil contact angle ≥120°. The precisely controlled pore size distribution ensures effective blocking of rainwater and dust contaminants (100–3000 μm) while allowing air molecules (0.0004 μm) to pass freely, achieving the function of free gas exchange filtration through membrane convection.

[0011] In a preferred embodiment of this invention, the elastic composite includes a pressure plate and a damping pad. The damping pad is disposed between the pressure plate and the valve plate to buffer vibration and provide elastic support for the valve plate. The pressure plate is assembled on the upper surface of the damping pad to fix its position and ensure unobstructed airflow. The composite elastic support structure ensures both the sensitivity of the valve plate's movement and the buffering of mechanical vibration, extending its service life.

[0012] In a preferred embodiment of this invention, the opening and closing seam includes straight, T-shaped, grid-shaped, star-shaped, spiral, or mesh-shaped seams; the seam width is 0.1–2 mm, and the length of a single seam is 3–15 mm. This diverse seam design can meet the air permeability requirements under different pressure differential conditions, ensuring rapid response and reliable sealing.

[0013] To solve the aforementioned technical problems, another technical solution adopted by this utility model is: providing a standard metric threaded moisture-proof, waterproof, and breathable pressure balancing valve with the aforementioned membrane assembly. The membrane assembly is disposed on the airflow channel of the valve body, with a waterproof and breathable membrane at the outer end of the airflow channel to block external liquids and dust, and a valve plate at the inner end of the airflow channel to dynamically regulate the internal air pressure balance. When the internal pressure of the space connected to the pressure balancing valve is less than the preset opening pressure, the valve plate remains closed, preventing the flow between the inside and outside and preventing moisture from entering. When the internal pressure of the space is less than the external pressure, the valve plate opens inward under negative pressure, allowing external gas to enter the interior after being filtered by the waterproof and breathable membrane, thus balancing the internal and external pressure difference. When the internal pressure of the space is greater than the external pressure, the valve plate opens outward under positive pressure, allowing internal gas to be discharged through the waterproof and breathable membrane, reducing the internal pressure. This achieves intelligent pressure self-regulation, effectively solving the condensation problem caused by temperature changes at its root.

[0014] In a preferred embodiment of this invention, the valve body connection end of the pressure balancing valve is provided with a standard metric thread structure, forming a mating connection with the matching housing. The standardized interface design facilitates installation and maintenance, improving product versatility and interchangeability.

[0015] In a preferred embodiment of the present invention, the valve body further includes an upper cover, which is disposed on the outside of the waterproof and breathable membrane to form a protective structure for it, thereby preventing mechanical damage and direct exposure to harsh environments and extending the service life of the core membrane assembly.

[0016] In a preferred embodiment of this invention, the waterproof and breathable diaphragm is fixed to the protrusion on the inside of the valve body by hot-melt, ultrasonic, or laser welding; the valve plate is fixed to the crossbeam on the inside of the valve body by hot-melt, ultrasonic, or laser welding. The reliable welding process ensures a stable and secure connection, avoiding failure problems caused by adhesive aging, and is suitable for mass automated production.

[0017] The beneficial effects of this utility model are: This utility model has dual functions of waterproof and breathable and pressure regulation. It not only blocks the entry of external liquids and particles, but also automatically adjusts the air permeability according to the pressure difference; it controls the entry of water vapor into the battery pack from the source, effectively solving the problem of internal and external pressure balance of the power battery pack and eliminating the phenomenon of fogging and condensation inside it. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of a preferred embodiment of the standard metric threaded moisture-proof, waterproof, and breathable pressure balancing valve with membrane components of this utility model. Figure 2 yes Figure 1 The diagram shows the structure of the pressure balancing valve in the negative pressure intake state. Figure 3 yes Figure 1 The diagram shows the structure of the pressure balancing valve in the positive pressure exhaust state. Figure 4 yes Figure 1 A schematic diagram of an embodiment of the opening and closing slit on the valve plate in the pressure balancing valve shown; The components in the attached diagram are labeled as follows: 1. Top cover; 2. Waterproof and breathable membrane; 3. Pressure plate; 4. Shock absorber; 5. Valve plate; 6. Sealing ring; 7. Valve body. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0020] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0021] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0022] In the description of this utility model, it should be noted that the terms "front," "rear," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this utility model. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0023] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0024] In this invention, unless otherwise expressly specified and limited, "above or below" the first feature may include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on" the first feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the first feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] Please see Figure 1 The embodiments of this utility model include: A waterproof and breathable membrane assembly, comprising: The waterproof and breathable membrane 2 is made of expanded polytetrafluoroethylene (ePTFE) microporous film with surface hydrophobic and oleophobic modification treatment, and is placed on the air inlet side of the breathable channel to form a waterproof and breathable barrier. The surface hydrophobic and oleophobic modification treatment includes coating the surface of the expanded polytetrafluoroethylene (ePTFE) microporous film with fluorocarbon adhesive, vacuuming out excess adhesive from the nanopores on one side of the film, and curing to form a hydrophobic and oleophobic expanded polytetrafluoroethylene (ePTFE) microporous film. The micropore size of the hydrophobic and oleophobic expanded polytetrafluoroethylene (ePTFE) microporous film is 0.01–15 μm, and the porosity is 50–90%. The water contact angle is ≥150°, and the oil contact angle is ≥120°.

[0026] Expanded polytetrafluoroethylene (ePTFE) microporous membranes for waterproof and breathable applications are highly elastic and flexible polymer materials with a three-dimensional nanoporous network structure formed by interconnected microfibers. After surface modification to enhance the micropores, the micropore size of the breathable membrane ranges from 0.01 to 15 μm. Water vapor molecules have a diameter of 0.0004 μm, while rainwater molecules range from 100 μm to 3000 μm. These microfibers, forming countless three-dimensional nanoporous pores, enable the free exchange and filtration of gas through the membrane layer, while rainwater and dust pollutants are blocked from passing through the microporous membrane surface.

[0027] Expanded polytetrafluoroethylene (ePTFE) microporous membranes, after being treated with nanoporous modification technology, become a new polymer material with special functions after surface oil and water repellency treatment. This modified ePTFE microporous membrane material, with its unique microporous structure, is named hydrophobic and oleophobic expanded polytetrafluoroethylene microporous membrane. The oleophobic expanded polytetrafluoroethylene microporous membrane, after surface modification, has smaller micropore openings composed of its fibers. Under certain pressure differential working environments, it exhibits better resistance to rainwater, dust, and chemical liquids, and can withstand corrosion from all substances within a pH range of 0–14 (except for molten alkali metals, sodium naphthalene solution, and elemental fluorine, especially at high temperatures). It also has a wider operating temperature range (-100°C to +260°C). Its unique chemical inertness, water and air permeability, oil repellency, and thermal stability make it highly suitable for the demanding filtration requirements and environmental climatic conditions of modern advanced equipment and other advanced electrical components.

[0028] An elastic composite is disposed between the waterproof and breathable membrane 2 and the valve plate 5 to provide support for the opening and closing of the valve plate 5. The elastic composite includes a pressure plate 3 and a damping pad 4, preferably an EPDM damping pad 4, which is positioned between the pressure plate 3 and the valve plate 5 to buffer vibration and provide elastic support for the valve plate 5. The pressure plate 3 is mounted on the upper surface of the damping pad 4 to fix its position and ensure unobstructed airflow. This elastic composite ensures both the sensitivity of the valve plate 5's movement and the buffering of mechanical vibration. Compared to traditional spring structures, it reduces manufacturing costs by 30% and extends product lifespan.

[0029] The valve plate 5 is a thin-walled elastic valve plate with a thickness of 0.1–0.5 mm, preferably made of silicone rubber or fluororubber with a hardness of 40–80 Shore A. It has dynamic opening and closing slits, including straight, T-shaped, grid, star-shaped, spiral, or mesh-shaped slits. The slit width is 0.1–2 mm, and the length of a single slit is 3–15 mm. For example, a T-shaped slit... Figure 4 As shown, the remaining structures are not illustrated.

[0030] Supported by the elastic composite, the valve plate 5 can dynamically open to form a breathable channel when the internal and external pressure difference reaches 0.5 to 10 kPa. After the pressure difference is eliminated, it automatically resets and closes. The response speed is 50% faster than that of traditional designs, ensuring rapid balance of internal and external pressure difference and improving moisture-proof and waterproof efficiency.

[0031] In another embodiment, a standard metric threaded pressure balancing valve with the membrane assembly is provided on the airflow channel of the valve body 7.

[0032] The waterproof and breathable membrane 2 is located at the outer end of the airflow channel to block external liquids and dust; the valve plate 5 is located at the inner end of the airflow channel to dynamically adjust the internal air pressure balance.

[0033] Specifically, the waterproof and breathable membrane 2 is fixed to the protrusion on the inner side of the valve body 7 by hot melting, ultrasonic welding or laser welding; the valve plate 5 is fixed to the crossbeam on the inner side of the valve body 7 by hot melting, ultrasonic welding or laser welding.

[0034] The dimensions, position, and shape of the waterproof and breathable membrane 2 and valve plate 5, as well as the dimensions, position, and shape of the openings, can be adjusted according to different working conditions and are closely matched with the internal structure on the valve body 7.

[0035] The valve body 7 of the pressure balancing valve has a standard metric thread at its connection end, forming a mating connection with the matching housing. A sealing ring 6 is provided between the valve body 7 and the matching housing. The standardized interface design facilitates installation and maintenance, allowing for rapid assembly with new energy battery packs or other housings, improving operational automation and reducing design costs. The valve body 7 is available in various colors to meet different application requirements, such as black, white, red, and green.

[0036] The working process of the pressure balancing valve of this utility model is as follows: Normal operating condition: When the internal pressure of the space connected to the pressure balancing valve is less than the preset opening pressure, the valve plate 5 remains closed, blocking the flow between inside and outside and preventing moisture from entering; thereby avoiding the formation of liquid accumulation due to the convection of dry and wet inside and outside, which could lead to short circuits and other malfunctions in the internal components of the space. Negative pressure intake state, such as Figure 2 As shown: When the internal pressure of the space is less than the external pressure, the valve plate 5 opens inward under negative pressure, and the external gas enters the interior after being filtered by the waterproof and breathable membrane 2, thus balancing the internal and external pressure difference and achieving pressure balance inside and outside the box. Positive pressure exhaust state, such as Figure 3 As shown: When the internal pressure of the space is greater than the external pressure, the valve plate 5 is opened to the outside under positive pressure, and the internal gas is discharged through the waterproof and breathable membrane 2, reducing the internal pressure and achieving pressure balance between the inside and outside of the box.

[0037] The valve body 7 also includes an upper cover 1, which is located on the outside of the waterproof and breathable membrane 2, forming a protective structure for it. The protective structure design extends the product's service life by 10 to 15 life cycles in harsh environments, and tests have proven that it can last for decades.

[0038] The application of standard metric thread moisture-proof, waterproof, and breathable pressure balance valves is used in power battery packs, vehicle headlight protection, electrical equipment waterproofing and breathability, or chemical filtration. Especially in the application of new energy vehicle battery packs, it can reduce the condensation-related failure rate by 60%, save 30% of maintenance costs, and improve the system safety level.

[0039] In summary, this utility model, through the design of a waterproof and breathable membrane component, effectively blocks the entry of external liquids and particles while automatically adjusting the air permeability according to the pressure difference to ensure the air pressure balance inside the equipment.

[0040] The waterproof and breathable membrane 2 uses expanded polytetrafluoroethylene (ePTFE) microporous film with surface hydrophobic and oleophobic modification treatment. It has extremely high water contact angle and oil contact angle, which can effectively block rainwater, dust and other pollutants, while allowing air molecules to pass freely. This controls water vapor from entering the battery pack at the source and effectively solves the condensation phenomenon caused by temperature changes.

[0041] The pressure balancing valve adopts a standard metric thread structure, which facilitates a mating connection with the matching housing, improves the product's versatility and interchangeability, and simplifies the installation and maintenance process.

[0042] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made using the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A waterproof and breathable membrane assembly, characterized in that, include: The waterproof and breathable membrane is made of expanded polytetrafluoroethylene (ePTFE) microporous film with surface hydrophobic and oleophobic modification treatment. It is placed on the air inlet side of the breathable channel to form a waterproof and breathable barrier. An elastic composite material is placed between the waterproof and breathable membrane and the valve plate to provide support for the opening and closing of the valve plate. A valve disc is a thin-walled elastic valve disc with dynamic opening and closing slits, which controls the opening and closing of the air passage under the support of an elastic composite.

2. The waterproof and breathable membrane assembly according to claim 1, characterized in that, The surface hydrophobic and oleophobic modification treatment includes coating the surface of the expanded polytetrafluoroethylene (ePTFE) microporous film with fluorocarbon adhesive, which, after curing, forms a hydrophobic and oleophobic expanded polytetrafluoroethylene (ePTFE) microporous film.

3. The waterproof and breathable membrane assembly according to claim 2, characterized in that, The micropore size of the hydrophobic and oleophobic expanded polytetrafluoroethylene (ePTFE) microporous film is 0.01–15 μm.

4. The waterproof and breathable membrane assembly according to claim 1, characterized in that, The elastic composite includes a pressure plate and a shock-absorbing pad. The shock-absorbing pad is located between the pressure plate and the valve plate to buffer vibration and provide elastic support for the valve plate. The pressure plate is assembled on the upper surface of the shock-absorbing pad to fix the position of the shock-absorbing pad and ensure the unobstructed air passage.

5. The waterproof and breathable membrane assembly according to claim 1, characterized in that, Opening seams include straight, T-shaped, grid, star-shaped, spiral, or mesh-shaped seams; the seam width of the opening seam is 0.1–2 mm, and the length of a single seam is 3–15 mm.

6. A standard metric threaded pressure balancing valve for moisture-proofing, waterproofing, and breathability of a membrane module having any one of claims 1 to 5, characterized in that, The membrane assembly is disposed on the airflow channel of the valve body. The waterproof and breathable membrane is disposed on the outer end of the airflow channel to block external liquids and dust. The valve plate is disposed on the inner end of the airflow channel to dynamically adjust the internal air pressure balance.

7. The standard metric threaded pressure balancing valve for moisture-proof, waterproof, and breathable applications according to claim 6, characterized in that, The valve body connection end of the pressure balancing valve is provided with a standard metric thread structure, which forms a mating connection with the matching housing.

8. The standard metric threaded pressure balancing valve for moisture-proof, waterproof, and breathable applications according to claim 6, characterized in that, The valve body also includes an upper cover, which is located on the outside of the waterproof and breathable membrane to form a protective structure for it.

9. The standard metric threaded pressure balancing valve for moisture-proof, waterproof, and breathable applications according to claim 6, characterized in that, The waterproof and breathable membrane is fixed to the protrusion on the inside of the valve body by hot melting, ultrasonic welding or laser welding; the valve plate is fixed to the crossbeam on the inside of the valve body by hot melting, ultrasonic welding or laser welding.

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