Ventilation parts

Abstract

To provide a ventilation component which is suitable for exhaustion for explosion prevention, and advantageous in a view point of the enhancement of reliability.SOLUTION: A ventilation valve 20 has a circular ring shape including a substantially-plate shaped structural portion, and a first end part 21 forming an internal peripheral part in a plane view and a second end part forming an external peripheral part. The structural portion has a support part 35 and a valve seat part. The support part 35 supports the first end part 21. The valve seat part contacts with the second end part when the ventilation valve 20 is closed, and separates from the second end part when the ventilation valve 20 is opened. The support part 35 has a first contact part 35f and a second contact part 35s which sandwich the first end part 21, and contacts with an end face 21e of the first end part 21 between the first contact part 35f and the second contact part 35s.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to a ventilation component. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there is known a device for correcting the difference between the pressure inside a housing and the pressure outside the housing.

[0003] For example, Patent Document 1 describes a pressure compensation device that can be used in a housing in which an undesirable pressure difference between the inside and outside must be avoided. This pressure compensation device has an inside and an outside, and includes a cage, a ventilation membrane, and a pressure release valve. The cage includes an inside half and an outside half. Inside the cage, between the inside half and the outside half, a ventilation membrane and a pressure release valve are arranged. Explosion prevention is achieved by the pressure release valve. When the pressure inside becomes greater than the pressure outside and the differential pressure exceeds a threshold, a flow path is formed that directly connects the inside and outside for emergency exhaust of the gas inside. Note that the ventilation membrane does not contribute to explosion prevention. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] German Patent Invention No. 102017003360 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 has room for improvement from the viewpoint of improving reliability. Therefore, the present invention provides a ventilation component that is suitable for exhaust for explosion prevention and is advantageous from the viewpoint of improving reliability. [Means for solving the problem]

[0006] The present invention provides A ventilation part attached to a housing at a ventilation port, A breathable membrane; a ventilation valve including an elastic body that opens and closes by elastic deformation of the elastic body; a structural member supporting the ventilation membrane and the ventilation valve; When the ventilation component is attached to the housing, the ventilation membrane ventilates the inside and outside of the housing, and when the difference between the pressure inside the housing and the pressure outside the housing reaches a predetermined pressure or more, the ventilation valve opens to discharge the gas inside the housing to the outside of the housing, The vent valve has two opposing surfaces, and when one of the two surfaces is viewed in plan, has an annular shape including a first end portion forming an inner periphery and a second end portion forming an outer periphery, the structural member has a support portion that supports the first end portion, and a valve seat portion that contacts the second end portion when the vent valve is closed and is spaced apart from the second end portion when the vent valve is open, the support portion has a first contact portion and a second contact portion that sandwich the first end portion, the first contact portion contacting one of a pair of opposing surfaces at the first end portion and the second contact portion contacting the other of the pair of surfaces, the support portion is in contact with an end surface of the first end portion connecting the pair of surfaces between the first contact portion and the second contact portion; Provide ventilation components. [Effects of the Invention]

[0007] The above-described ventilation component is suitable for exhausting air to prevent explosion, and is advantageous from the viewpoint of increasing reliability. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a bottom view showing an example of the ventilation part of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of the ventilation component taken along line II-II in FIG. [Figure 3] FIG. 3 is a perspective view showing the ventilation opening of the housing. [Figure 4] FIG. 4 is a cross-sectional view showing a state in which the ventilation part is attached to the housing. [Figure 5] FIG. 5 is a cross-sectional view showing the vent valve in an open state. [Figure 6A] FIG. 6A is a plan view of the vent valve. [Figure 6B] FIG. 6B is a plan view of the vent valve. [Figure 7] 7 is an enlarged cross-sectional view of a portion of the ventilation component shown in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] For example, the housing of a vehicle's electrical components needs to be breathable so that pressure differences generated inside the housing due to temperature changes can be resolved. However, the level of breathability required for a housing can vary depending on events occurring inside the housing. For example, it may be necessary to be able to quickly release a large amount of gas from inside the housing, such as to protect a battery pack from explosion. Therefore, a ventilation component equipped with a ventilation membrane and a ventilation valve can be attached to the ventilation opening of the housing. In this case, for example, normal ventilation is performed using the ventilation membrane with the ventilation valve closed. When the difference between the pressure inside the housing and the pressure outside the housing increases above a predetermined pressure, the ventilation valve opens, allowing a large amount of gas to be quickly released from inside the housing. If a ventilation valve that opens and closes by elastic deformation of an elastic body is used as the ventilation valve, the ventilation valve can be reused.

[0010] In the pressure compensation device described in Patent Document 1, the pressure release valve is disposed inside a cage, and the inner half of the cage sandwiches the inner periphery of the pressure release valve in the thickness direction of the pressure release valve. The end face of the inner periphery of the pressure release valve does not contact the inner half of the cage. The inventors have determined that improving the sealing performance between the vent valve and the member supporting the vent valve is extremely important for the reliability of a venting component or a product equipped with the venting component. Based on their investigations, the inventors found that the technology described in Patent Document 1 does not provide a sufficiently high sealing performance between the pressure release valve and the inner half of the cage. Therefore, the inventors have conducted extensive research into techniques for improving the sealing performance between the vent valve and the member supporting the vent valve. As a result, they have come up with a new idea of configuring the vent valve and the member supporting the vent valve to satisfy a predetermined relationship, and have devised the venting component of the present invention. The housing in which the venting component of the present invention is installed is not limited to the housing of a vehicle electrical component.

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The following description is an example of the present invention, and the present invention is not limited to the following embodiments.

[0012] As shown in FIGS. 1 and 2 , the ventilation component 1 includes a ventilation membrane 10, a ventilation valve 20, and a structural member 30. The ventilation component 1 is a component that is attached to a housing 2 having a ventilation opening 5, as shown in FIG. 3 . As shown in FIG. 4 , the ventilation component 1 is attached to the housing 2 at the ventilation opening 5. As shown in FIGS. 4 and 5 , the ventilation valve 20 includes an elastic body and opens and closes by elastic deformation of the elastic body. The structural member 30 supports the ventilation membrane 10 and the ventilation valve 20. When the ventilation component 1 is attached to the housing 2, the ventilation membrane 10 ventilates the interior and exterior of the housing 2. Additionally, when the difference between the pressure inside the housing 2 and the pressure outside the housing 2 reaches or exceeds a predetermined pressure, the ventilation valve 20 opens and releases gas from the housing 2 to the exterior. In other words, when the difference between the pressure inside the housing 2 and the pressure outside the housing 2 is less than a predetermined pressure, the ventilation valve 20 is closed. As shown in FIG. 2, the vent valve 20 includes a generally plate-shaped structural portion having two opposing surfaces 20f and 20s. Additionally, as shown in FIGS. 6A and 6B, the vent valve 20 has a first end 21 and a second end 22. The first end 21 forms an inner periphery when one of the two surfaces 20f and 20s is viewed in plan, and the second end 22 forms an outer periphery at a position spaced apart from the first end 21. As shown in FIG. 2, the structural member 30 has a support portion 35 and a valve seat portion 36. The support portion 35 supports the first end 21. As shown in FIGS. 4 and 5, the valve seat portion 36 contacts the second end 22 when the vent valve 20 is closed and is spaced apart from the second end 22 when the vent valve is open.

[0013] As shown in FIG. 7 , the support portion 35 has a first contact portion 35f and a second contact portion 35s. The first contact portion 35f and the second contact portion 35s sandwich the first end portion 21 of the vent valve 20. The first contact portion 35f contacts the surface 21q, which is one of a pair of opposing surfaces 21p at the first end portion 21. In addition, the second contact portion 35s contacts the surface 21r, which is the other of the pair of surfaces 21p at the first end portion 21. The support portion 35 contacts the end surface 21e of the first end portion 21, which connects the pair of surfaces 21p, between the first contact portion 35f and the second contact portion 35s. The first end portion 21 is sandwiched between the first contact portion 35f and the second contact portion 35s, and is also in contact with the support portion 35 at the end surface 21e. This provides a high level of sealing between the vent valve 20 and the support portion 35. As a result, liquid and gas do not pass between the support portion 35 and the first end portion 21, and the reliability of the ventilation part 1 and a product to which the ventilation part 1 is attached can be improved.

[0014] In the past, it was thought that, from the viewpoint of ensuring the movability of the vent valve, it was necessary for the end face of the inner periphery of the vent valve not to come into contact with the support part. However, according to the study by the present inventors, it was newly discovered that even if the end face of the inner periphery of the vent valve comes into contact with the support part, the movability of the vent valve can be ensured and the reliability of the vent part and the product to which the vent part is attached can be improved.

[0015] For example, in a state where the elastic body of the vent valve 20 is pressed against the support portion 35 due to elastic deformation, the end surface 21e of the first end portion 21 is in contact with the support portion 35. In this case, the sealing performance between the vent valve 20 and the support portion 35 is high.

[0016] For example, the first end 21 is in liquid-tight contact with the support portion 35 at the end surface 21e. Preferably, the first end 21 is in liquid-tight and airtight contact with the support portion 35 at the end surface 21e. In this case, the sealing performance between the vent valve 20 and the support portion 35 is likely to be improved. In this case, airtightness means that the pressure difference between the two spaces separated by the end surface 21e can be maintained at 10 kPa or more.

[0017] The first contact portion 35f and the second contact portion 35s are in contact with the first end portion 21, for example, in a state where the elastic body of the vent valve 20 is pressed against the first end portion 21 so as to elastically deform. The first contact portion 35f and the second contact portion 35s are in liquid-tight contact with the first end portion 21, for example. The first contact portion 35f and the second contact portion 35s are preferably in liquid-tight and airtight contact with the first end portion 21. In this case, airtightness means that the pressure difference between the two spaces separated by the first contact portion 35f or the second contact portion 35s can be maintained at 10 kPa or more. As shown in FIGS. 6A and 6B , the vent valve 20 has a through hole 25 in its center. The first end portion 21 is adjacent to the through hole 25.

[0018] As shown in FIGS. 6A and 6B , the vent valve 20 is, for example, a type of so-called umbrella valve (umbrella-shaped open valve). When one of the two surfaces 20f and 20s is viewed in plan, it has a circular ring shape including an inner circumferential portion forming the first end 21 and an outer circumferential portion forming the second end 22. Therefore, if the support portion 35 has a circular ring shape, when the end surface 21e of the elastic body of the vent valve 20 is pressed against the support portion 35 by elastic deformation and is in contact with the support portion 35, the amount of deformation of the elastic body is likely to be uniform around the axis of the vent valve 20. Umbrella valves typically include a valve portion that opens and closes and a stem portion that supports the valve portion. Some umbrella valves have a valve portion and another stem portion that are separate components. The vent valve 20, for example, comprises only the valve portion, and the valve portion has a circular ring shape when viewed in plan. Meanwhile, the structural member 30 serves as a stem portion that supports the valve portion, i.e., the vent valve 20. The through hole 25 of the vent valve 20 is used to support the vent valve 20 with the structural member 30. When the vent component 1 is viewed in plan, the vent membrane 10 is disposed inside the inner circumferential surface that forms the through hole 25 of the vent valve 20. In this way, the through hole 25 of the vent valve 20 is large enough to accommodate the vent membrane 10.

[0019] For example, the inner diameter of the inner periphery forming the first end 21 of the vent valve 20 when not attached to the support part 35 is smaller than the maximum dimension in a direction perpendicular to the axis of the vent valve 20 of the part that contacts the end face 21e of the support part 35. This makes it easier for the end face 21e to come into contact with the support part 35 when the elastic body of the vent valve 20 is pressed against the support part 35 due to elastic deformation.

[0020] 1 and 2, the structural member 30 has, for example, an engaging portion 32c. The engaging portion 32c is inserted into the ventilation hole 5 of the housing 2. The ventilation component 1 further includes, for example, a sealing member 60. As shown in FIG. 4, the sealing member 60, in the attached state, seals the gap between the structural member 30 and the outer surface 2s of the housing 2 on which the ventilation component 1 is attached. This prevents liquid from passing between the structural member 30 and the outer surface 2s and being introduced into the housing 2. The sealing member 60 is, for example, an O-ring or a packing. The material of the sealing member 60 is, for example, an elastically deformable material.

[0021] The breathable membrane 10 is not limited to a specific breathable membrane as long as it has the desired breathability. The breathable membrane 10 may be a single-layer membrane or a multi-layer membrane. When the breathable membrane 10 is a multi-layer membrane, each layer may be one selected from the group consisting of a porous membrane, a nonwoven fabric, a cloth, and a mesh. The breathable membrane 10 may include a porous membrane and a nonwoven fabric, or may include a porous membrane and at least one of a cloth and a mesh, or may include multiple nonwoven fabrics. The breathable membrane 10 is typically made of an organic polymer material (resin). The porous membrane is made of, for example, a fluororesin. Examples of fluororesins that can be used include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, and tetrafluoroethylene-ethylene copolymer. Examples of materials for the nonwoven fabric, cloth, and mesh include polyesters such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, nylon, aramid, and ethylene-vinyl acetate copolymer.

[0022] The breathable membrane 10 may be subjected to a liquid-repellent treatment as necessary. The liquid-repellent treatment is performed, for example, by forming a liquid-repellent coating containing a fluorine-based surface modifier having a perfluoroalkyl group on the breathable membrane 10. The method for forming the liquid-repellent coating is not particularly limited, and may be performed, for example, by coating the porous resin membrane with a solution or dispersion of a fluorine-based surface modifier having a perfluoroalkyl group by air spraying, electrostatic spraying, dip coating, spin coating, roll coating, curtain flow coating, impregnation, or other methods. Alternatively, the liquid-repellent coating may be formed by electrodeposition coating or plasma polymerization.

[0023] The vent valve 20 opens by elastic deformation and closes by returning to its original shape before deformation. Therefore, the vent valve 20 can be repeatedly opened and closed, and can be used repeatedly. This has the advantage that the vent valve 20 can be inspected to check whether it operates normally in a product in which the ventilation component 1 is attached to the housing 2, and then the inspected product can be shipped.

[0024] 2, the surface 20f of the vent valve 20 is formed without a step between the first end 21 and the portion of the vent valve 20 adjacent to the first end 21. This tends to increase the contact area between the first end 21 and the support portion 35.

[0025] 2, the surface 20s of the vent valve 20 is formed so as to have a step between the first end 21 and a portion adjacent to the first end 21 of the vent valve 20. Therefore, the thickness of the first end 21 is greater than the thickness of the portion adjacent to the first end 21 of the vent valve 20. This tends to increase the amount of deformation of the first end 21 held by the support portion 35, improving the sealing performance between the vent valve 20 and the support portion 35. In addition, the pressure difference required to open the vent valve 20 can be easily adjusted to a desired range.

[0026] 2, the structural portion of the vent valve 20 has a bent portion between the portion adjacent to the second end 22 of the vent valve 20 and the second end 22, and the bent portion is bent inward of the vent valve 20. This tends to increase the contact area between the second end 22 and the valve seat 36 when the vent valve 20 is closed. As a result, the sealing performance between the second end 20 and the valve seat 36 is high when the vent valve 20 is closed.

[0027] The elastic body included in the vent valve 20 is not limited to a specific material as long as it is an elastically deformable material. The elastic body included in the vent valve 20 is, for example, an elastomer such as natural rubber, synthetic rubber, or thermoplastic elastomer. In this case, the synthetic rubber is, for example, nitrile butadiene rubber (NBR), ethylene propylene rubber (EPDM), silicone rubber, fluororubber, acrylic rubber, or hydrogenated nitrile rubber. The vent valve 20 preferably includes silicone rubber as the elastic body. These elastic bodies can also be used as materials for the seal member 60.

[0028] As shown in FIG. 2 , the structural member 30 includes, for example, a first member 31 and a second member 32. The first member 31 supports the breathable membrane 10. The first member 31 includes a base 31b and a shaft 31s. The base 31b is, for example, disk-shaped and supports the breathable membrane 10. The base 31b has a through-hole 31h at its center for ventilation. The base 31b supports the peripheral edge of the breathable membrane 10 outside the through-hole 31h in a direction perpendicular to the axis of the base 31b. The breathable membrane 10 is fixed to the base 31b by, for example, heat welding, ultrasonic welding, or bonding with an adhesive. The shaft 31s protrudes from the center of the base 31b in the axial direction of the base 31b. The shaft 31s is cylindrical and has multiple (e.g., three) legs 31g positioned away from the base 31b in the axial direction of the base 31b. The multiple legs 31g are, for example, spaced apart equiangularly around the axis of the base 31b. Each of the multiple legs 31g has an engagement portion 31c at its tip that protrudes in a direction perpendicular to the axis of the base 31b. Gas flows in and out of the inside of the shaft 31s, between the legs 31g, and through the through-holes 31h, thereby providing ventilation.

[0029] The second member 32 forms the bottom and side of the structural member 30. The second member 32 is an annular member and includes an inner circumferential portion 32i, an outer circumferential portion 32e, and a connecting portion 32k. The inner circumferential portion 32i is located at the center of the second member 32 and is cylindrical. The outer circumferential portion 32e is spaced from the inner circumferential portion 32i in a direction perpendicular to the axis of the inner circumferential portion 32i and surrounds the inner circumferential portion 32i. The outer circumferential portion 32e forms the side of the structural member 30. The connecting portion 32k is located between the outer circumferential portion 32e and the inner circumferential portion 32i in a direction perpendicular to the axis of the inner circumferential portion 32i and connects the outer circumferential portion 32e and the inner circumferential portion 32i. The inner circumferential portion 32i and the connecting portion 32k form the bottom of the structural member 30. The inner circumferential portion 32i has a mounting hole 32h, which is a through-hole, in its center. The first member 31 is attached to the second member 32 at one end of the inner circumferential portion 32i in the axial direction. The mounting hole 32h at one end of the inner circumferential portion 32i is a tapered hole. In addition, the inner circumferential portion 32i has an annular engagement surface 32f adjacent to the tapered hole and extending in a direction perpendicular to the axis of the inner circumferential portion 32i. The shaft portion 31s is inserted into the tapered hole of the mounting hole 32h, and the engagement portion 31c faces the engagement surface 32f, preventing the first member 31 from coming off the mounting hole 32h. In addition, the end face of the inner circumferential portion 32i adjacent to the tapered hole in the axial direction of the inner circumferential portion 32i faces the bottom surface of the base portion 31b of the first member 31.

[0030] The support portion 35 is formed, for example, by the bottom surface of the base portion 31b of the first member 31 and the outer surface of one end of the inner circumferential portion 32i in the axial direction.

[0031] The inner peripheral surface of the inner peripheral portion 32i is formed to have multiple (e.g., three) steps from the engagement surface 32f toward the other end of the inner peripheral portion 32i in the axial direction. For example, the inner peripheral surface of the inner peripheral portion 32i has a first side surface 32p, a second side surface 32q, a third side surface 32r, a first connecting surface 32t, and a second connecting surface 32u. The first side surface 32p, the second side surface 32q, and the third side surface 32r extend in the axial direction of the inner peripheral portion 32i. In addition, the first side surface 32p, the second side surface 32q, and the third side surface 32r have a first inner diameter, a second inner diameter, and a third inner diameter, respectively. The first inner diameter is smaller than the second inner diameter, and the second inner diameter is smaller than the third inner diameter. The first connecting surface 32t and the second connecting surface 32u extend in a direction perpendicular to the axis of the inner peripheral portion 32i. The first connecting surface 32t connects the first side surface 32p and the second side surface 32q, and the second connecting surface 32u connects the second side surface 32q and the third side surface 32r.

[0032] As shown in FIG. 1, the inner circumferential portion 32i includes, for example, a plurality of (e.g., three) engaging portions 32c. The engaging portions 32c protrude outward in a direction perpendicular to the axis of the inner circumferential portion 32i, for example, at the other end of the inner circumferential portion 32i in the axial direction of the inner circumferential portion 32i. The engaging portions 32c are, for example, plate-shaped portions curved in an arc. The plurality of engaging portions 32c are, for example, arranged equiangularly spaced apart around the axis of the inner circumferential portion 32i. As shown in FIG. 3, in the housing 2, a portion of the ventilation opening 5 is formed by a plurality of (e.g., three) protruding portions 5p. The plurality of protruding portions 5p are arranged equiangularly spaced apart around the axis of the ventilation opening 5, and a plurality of grooves 5r that form part of the ventilation opening 5 are present between the protruding portions 5p. When the ventilation component 1 is attached to the housing 2, the ventilation component 1 is inserted into the ventilation opening 5 so that the engaging portions 32c pass through the grooves 5r. Thereafter, the ventilation component 1 is rotated by a predetermined angle around the axis of the inner circumferential portion 32i so that the engaging portion 32c faces the protruding portion 5p inside the housing 2, thereby attaching the ventilation component 1 to the housing 2. Cooperation between the protruding portion 5p and the engaging portion 32c prevents the ventilation component 1 from coming off the housing 2.

[0033] The vent valve 20 is attached to the inner periphery 32i so as to be in contact with the outer periphery of the inner periphery 32i which forms part of the support part 35. For example, the hole diameter of the through hole 25 of the vent valve 20 is determined so as to be in contact with the outer periphery of the inner periphery 32i.

[0034] The connecting portion 32k has, for example, a valve seat portion 36, which serves as a valve seat for the vent valve 20. The valve seat portion 36 is located on the periphery of the connecting portion 32k. The connecting portion 32k has a flow path 32d for allowing gas to flow. The flow path 32d is formed between the valve seat portion 36 and the inner circumferential portion 32i so as to be continuous in the axial direction of the inner circumferential portion 32i. The vent valve 20 is subjected to the pressure inside the housing 2 by the flow path 32d.

[0035] The connecting portion 32k further includes, for example, an annular groove 32g. The annular groove 32g accommodates a seal member 60. The annular groove 32g is formed in the bottom surface of the connecting portion 32k so as to overlap with the valve seat portion 36 in a direction perpendicular to the axis of the inner circumferential portion 32i.

[0036] The outer peripheral portion 32e extends along the axial direction of the inner peripheral portion 32i outside the connecting portion 32k. The outer peripheral portion 32e has an outward protruding portion 32j that protrudes outward in a direction perpendicular to the axis of the inner peripheral portion 32i.

[0037] The outer peripheral portion 32e has, for example, a plurality of inward protrusions 32v. The inward protrusions 32v protrude inward in a direction perpendicular to the axis of the inner peripheral portion 32i from one end of the outer peripheral portion 32e in the axial direction of the inner peripheral portion 32i. The multiple inward protrusions 32v are spaced apart at predetermined intervals around the axis of the inner peripheral portion 32i.

[0038] 1 and 2 , the structural member 30 further includes, for example, a third member 33. The third member 33 is, for example, a disk-shaped member. The third member 33 cooperates with the first member 31 and the second member 32 to form an internal space 40. The breathable membrane 10 and the breathable valve 20 are housed in, for example, the internal space 40. The third member 33 covers the breathable membrane 10 and the breathable valve 20, protecting them.

[0039] The third member 33 has a disk-shaped lid portion 33c and an engagement claw 33e. The engagement claw 33e protrudes from the peripheral edge of one main surface of the lid portion 33c in the axial direction of the lid portion 33c. The tip of the engagement claw 33e protrudes outward in a direction perpendicular to the axis of the lid portion 33c. The third member 33 is inserted into the outer circumferential portion 32e so that the engagement claw 33e passes through the gap between the inward protrusions 32v. The third member 33 is then rotated by a predetermined angle around the axis of the lid portion 33c so that the tip of the engagement claw 33e faces the inward protrusion 32v. In this manner, the third member 33 is attached to the second member 32. The tip of the engagement claw 33e faces the inward protrusion 32v, preventing the third member 33 from coming off the second member 32.

[0040] 1, the structural member 30 has an air passage 50. The air passage 50 ventilates the internal space 40 and the external space of the ventilated component 1. The air passage 50 is formed, for example, between the connecting portion 32k and the inner surface of the outer peripheral portion 32e.

[0041] The structural member 30 may be made of, for example, a synthetic resin or a metal. Examples of the synthetic resin include thermoplastic resin. Examples of the thermoplastic resin include polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polysulfone (PS), polypropylene (PP), polyethylene (PE), and ABS resin. The structural member 30 may be made of a composite material containing a thermoplastic resin as a matrix material. In this case, the reinforcing agent added to the composite material may be glass fiber, carbon fiber, metal, or an inorganic filler.

[0042] As shown in FIG. 4, when the difference between the pressure inside the housing 2 and the pressure outside the housing 2 is less than a predetermined pressure, the vent valve 20 is closed, and gas inside the housing 2 cannot move to the outside of the housing 2 through the flow path 32d. Therefore, gas flows in and out of the housing 2 through a flow path including the mounting hole 32h in the inner circumferential portion 32i, the through-hole 31h in the first member 31, the gas permeable membrane 10, the internal space 40, and the ventilation path 50. On the other hand, as shown in FIG. 5, when the difference between the pressure inside the housing 2 and the pressure outside the housing 2 is equal to or greater than a predetermined pressure, the vent valve 20 opens, and gas inside the housing 2 is discharged to the outside of the housing 2 through a flow path including the flow path 32d, the internal space 40, and the ventilation path 50. The gas flow path formed by the opening of the vent valve 20 does not include the gas permeable membrane 10, allowing a large amount of gas to be discharged from the inside of the housing 2 in a short period of time. A sudden increase in pressure inside the housing may damage the gas permeable membrane, even if a vent valve is provided. However, the ventilating component 1 has a structure that can suppress such a phenomenon. One possible means of preventing damage to the vent membrane or the like is to provide a structure that uses a vent valve to quickly release gas inside the housing to the outside of the housing. To achieve this, it is important to adjust the cross-sectional area of the flow path through which the gas passes and the size of the valve portion of the vent valve that blocks it. In a plan view of the ventilating component 1, the vent valve 20 has an annular shape with a through-hole in the center. Furthermore, the ventilating component 1 has a structure in which the vent membrane 10 is housed so that, in a plan view, the vent membrane 10 is positioned inside the inner circumferential surface that forms the through-hole 25 of the vent valve 20. This ensures that the cross-sectional area of the flow path through which the gas passes and the valve portion of the vent valve 20 are as large as possible within the limited space of the ventilating component 1. As a result, when the pressure inside the housing 2 suddenly increases, the vent valve 20 opens, allowing gas to be quickly released to the outside of the housing 2 through a flow path including the flow path 32d and the internal space 40.

Claims

1. A ventilation part attached to a housing at a ventilation port, A breathable membrane; a ventilation valve including an elastic body that opens and closes by elastic deformation of the elastic body; a structural member supporting the ventilation membrane and the ventilation valve; When the ventilation component is attached to the housing, the ventilation membrane ventilates the inside and outside of the housing, and when the difference between the pressure inside the housing and the pressure outside the housing reaches a predetermined pressure or more, the ventilation valve opens to discharge the gas inside the housing to the outside of the housing, The vent valve has two opposing surfaces, and when one of the two surfaces is viewed in plan, has an annular shape including a first end portion forming an inner periphery and a second end portion forming an outer periphery, the structural member has a support portion that supports the first end portion, and a valve seat portion that contacts the second end portion when the vent valve is closed and is spaced apart from the second end portion when the vent valve is open, the support portion has a first contact portion and a second contact portion that sandwich the first end portion, the first contact portion contacting one of a pair of opposing surfaces at the first end portion and the second contact portion contacting the other of the pair of surfaces, the support portion is in contact with an end surface of the first end portion connecting the pair of surfaces between the first contact portion and the second contact portion, the support portion includes a first member having the first contact portion and a second member having the second contact portion; the first member is fixed to the second member at a position closer to the second contact portion than to the first contact portion, the second member is in contact with the end surface of the first end portion connecting the pair of surfaces of the vent valve; Ventilation parts.

2. the structural member has an engagement portion that is inserted into the ventilation hole of the housing, The ventilation component may further include a sealing member that seals a gap between the structural member and an outer surface of the housing on which the ventilation component is attached in the attached state. The ventilation component according to claim 1 .

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