Ventilation components and ventilation structures

Abstract

To provide a ventilation component which is advantageous from the viewpoint of preventing the ventilation component from moving away from a projection of a housing after it is attached to the projection.SOLUTION: A ventilation component 1a comprises an internal member 10, a ventilation film 20 and an external member 30. The internal member 10 includes an elastic material and has an open tube structure. The ventilation film 20 covers one opening 13 of the internal member 10. The external member 30 has a closed tube structure. The internal member 10 is fixed to the external member 30 while forming a first contact part 5c with a portion of an inner peripheral surface of the external member 30. The first contact part 5c is disposed between a center C10 and the one opening 13. An inner diameter of the external member 30 is larger than an outer diameter of the internal member 10 between the first contact 5c and another opening 14. The external member 30 includes a protrusion 31p forming the first contact part 5c. A gap 30g exists around the protrusion 31p.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] This invention relates to ventilation components and ventilation structures. [Background technology]

[0002] Ventilation components may be fixed to the enclosures of automotive electrical components such as lamps, inverters, converters, electronic control units (ECUs), battery packs, radars, and cameras, as well as various electronic devices for home, medical, and office use. For example, ventilation components may be fixed to the enclosure to ensure ventilation inside and outside the enclosure, or to mitigate pressure fluctuations inside the enclosure. In addition to ventilation, ventilation components are required to have various properties depending on the specific use of the enclosure to which they are fixed, such as dustproofness to prevent dust from entering the enclosure, waterproofness to prevent water from entering, oilproofness to prevent oil from entering, and CCT resistance to prevent salt from entering.

[0003] For example, Patent Document 1 describes a ventilation component that can be fixed to a projection of a housing. This ventilation component comprises an internal member, a ventilation membrane, and an external member. The internal member has a projection that protrudes outward from its outer circumference. The external member has a latching portion that latches onto the projection. When viewed in plan along the axes of the internal member and the external member, the outer diameter of the projection is O B , inner diameter I of the latching part H , and the inner diameter O of the part of the external member facing the protruding portion O However, I H <O B <O O The following conditions are met. This ventilation component is described as being advantageous in eliminating problems associated with the deformation of internal components that are deformed by the protrusions of the housing when fixed to the housing protrusions. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2021 / 145383 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The ventilation component described in Patent Document 1 deserves reconsideration from the viewpoint of preventing the ventilation component from moving away from the projection after it has been attached to the projection of the housing.

[0006] Therefore, the present invention provides a ventilation component that is advantageous in that it prevents the ventilation component from moving away from the protrusion after it has been attached to the protrusion of the housing. [Means for solving the problem]

[0007] The present invention A ventilation component, An internal member containing an elastic material and having an open tube structure, A ventilation membrane covering one of the openings of the internal member, It comprises an external member having a closed pipe structure, The internal member is fixed to the external member such that it is inserted into the external member and a portion of the outer circumferential surface of the internal member is elastically deformed to form a first contact portion with a portion of the inner circumferential surface of the external member. The ventilation component is fixed in such a state that a projection protruding cylindrically from the outer surface of the housing toward the edge of a ventilation opening that connects the internal space and the external space of the housing is inserted into the interior of the internal member from the other opening of the internal member, and the inner circumferential surface of the internal member is elastically deformed to form a second contact portion with the outer circumferential surface of the projection. The first contact portion is positioned between the center in the axial direction of the portion of the internal member that overlaps with the external member in the axial direction of the internal member and the one opening. The inner diameter of the external member is greater than the outer diameter of the internal member in the axial direction between the first contact portion and the other opening of the internal member. The internal member and the external member have a projection formed on the inner circumferential surface of the external member or the outer circumferential surface of the internal member that forms the first contact portion. Around the axis of the internal member, a gap exists between the inner surface of the external member and the outer surface of the internal member around the protruding portion. We provide ventilation components.

[0008] Furthermore, the present invention is The casing and An internal member containing an elastic material and having an open tube structure, A ventilation membrane covering one of the openings of the internal member, It comprises an external member having a closed pipe structure, The internal member is fixed to the external member such that it is inserted into the external member and a portion of the outer circumferential surface of the internal member is elastically deformed to form a first contact portion with a portion of the inner circumferential surface of the external member. The housing has a projection on its outer surface that protrudes in a cylindrical shape toward the edge of a ventilation opening that connects the internal space and the external space of the housing, The projection is inserted into the interior of the internal member through the other opening of the internal member, and the inner circumferential surface of the internal member is elastically deformed and fixed in a state in which it forms a second contact portion with the outer circumferential surface of the projection. The first contact portion is positioned between the center in the axial direction of the portion of the internal member that overlaps with the external member in the axial direction of the internal member and the one opening. The inner diameter of the external member is greater than the outer diameter of the internal member in the axial direction between the first contact portion and the other opening of the internal member. The internal member and the external member have a projection formed on the inner circumferential surface of the external member or the outer circumferential surface of the internal member that forms the first contact portion. Around the axis of the internal member, a gap exists between the inner surface of the external member and the outer surface of the internal member around the protruding portion. Provides a ventilated structure. [Effects of the Invention]

[0009] The above-mentioned ventilation component is advantageous in that it prevents the ventilation component from moving away from the protrusion after it has been attached to the protrusion of the housing.

Brief Description of the Drawings

[0010] [Figure 1A] FIG. 1A is a plan view showing an example of a ventilation component according to the present invention. [Figure 1B] FIG. 1B is a side view of the ventilation component shown in FIG. 1A. [Figure 1C] FIG. 1C is a side view when the ventilation component is viewed in the direction shown by arrow C in FIG. 1A. [Figure 2A] FIG. 2A is a cross-sectional view of the ventilation component taken along line A-A in FIG. 1A. [Figure 2B] FIG. 2B is a cross-sectional view of the ventilation component taken along line B-B in FIG. 1A. [Figure 3] FIG. 3 is a cross-sectional view of the ventilation component taken along line III-III in FIG. 2A. [Figure 4] FIG. 4 is a cross-sectional view showing an example of a ventilation structure provided with the ventilation component shown in FIG. 1A. [Figure 5] FIG. 5 is a perspective cross-sectional view schematically showing the forces acting when a ventilation component according to a reference example is attached to a protrusion of a housing. [Figure 6A] FIG. 6A is a cross-sectional view showing another example of a ventilation component according to the present invention. [Figure 6B] FIG. 6B is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 6C] FIG. 6C is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 6D] FIG. 6D is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 6E] FIG. 6E is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 6F] FIG. 6F is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 6G] FIG. 6G is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 7A]Figure 7A is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 7B] Figure 7B is a cross-sectional view of the ventilation component with the VIIB-VIIB line in Figure 7A as the cutting line. [Figure 7C] Figure 7C is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 7D] Figure 7D is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 8A] Figure 8A is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 8B] Figure 8B is a cross-sectional view of the ventilation component with the line VIIIB-VIIIB in Figure 8A as the cutting line. [Figure 8C] Figure 8A is a cross-sectional view showing yet another example of a ventilation component according to the present invention. [Figure 9] Figure 9 is a graph showing the relationship between the average value of the change in the ventilation structure for Example 1 and Comparative Example 1 and the test time. [Figure 10] Figure 10 is a graph showing the relationship between the average value of the change in the ventilation structure in Example 2 and Comparative Example 2 and the test time. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the following embodiments.

[0012] As shown in Figures 1A, 1B, 1C, 2A, and 2B, the ventilation component 1a comprises an internal member 10, a ventilation membrane 20, and an external member 30. The internal member 10 contains an elastic material and has an open pipe structure. In other words, the internal member 10 is formed in a tubular shape with openings at both ends. The ventilation membrane 20 covers one of the openings 13 of the internal member 10. The external member 30 has a closed pipe structure. In other words, the external member 30 is formed in a tubular shape with an opening at only one of its ends. The internal member 10 is inserted into the external member 30 and fixed to the external member 30 with a portion of its outer circumferential surface elastically deformed to form a first contact portion 5c with a portion of its inner circumferential surface. The first contact portion 5c is centered C in the axial direction of the internal member 10. 10 It is positioned between and one of the openings 13. Center C 10 This is the axial center of the portion of the internal member 10 that overlaps with the external member 30 in the axial direction of the internal member 10. The inner diameter of the external member 30 is larger than the outer diameter of the internal member 10 between the first contact portion 5c and the other opening 14 in the axial direction of the internal member 10. As shown in Figure 3, the external member 30 has a protrusion 31p that forms the first contact portion 5c. The protrusion 31p is formed on the inner circumferential surface of the external member 30. Around the axis of the internal member 10, a gap 30g exists between the inner circumferential surface of the external member 30 and the outer circumferential surface of the internal member 10 around the protrusion 31p.

[0013] As shown in Figure 4, the ventilation component 1a can be fixed to the projection 2p of the housing 2a such that the projection 2p is inserted into the interior of the internal member 10 from the other opening 14 of the internal member 10, and the inner circumferential surface 12 of the internal member 10 is elastically deformed to form a second contact portion 6c with the outer circumferential surface 2q of the projection 2p. This provides the ventilation structure 3a. The projection 2p protrudes cylindrically from the outer surface of the housing 2a toward the edge 2f of the ventilation opening that connects the internal space 2u and the external space 2v of the housing 2a.

[0014] In the ventilation component 1a, since the internal member 10 is fixed to the external member 30 so as to form the first contact portion 5c, the axis Ax of the internal member 10 is less likely to incline with respect to the axis of the external member 30. When attaching the ventilation component 1a to the projection 2p of the housing 2a, for example, the external member 30 is gripped. If the internal member 10 is not fixed to the external member 30 so as to form the first contact portion 5c, there is a possibility that the axis Ax of the internal member 10 inclines with respect to the axis of the external member 30 and the ventilation component 1a cannot be properly attached to the projection 2p of the housing 2a. In the ventilation component 1a, since the internal member 10 is fixed to the external member 30 so as to form the first contact portion 5c, such a problem is less likely to occur, and it is easy to attach the ventilation component 1a to the projection 2p of the housing 2a in a desired state.

[0015] For example, when the internal member 10 before being fixed to the external member 30 is viewed in plan in a direction parallel to the axis Ax of the internal member 10, the diameter D of the circumcircle circumscribing the portion of the internal member 10 that forms the first contact portion 5c 10 is larger than the diameter D of the incircle inscribed in the portion of the external member 30 that forms the first contact portion 5c. 30 Thereby, in the ventilation component 1a, the first contact portion 5c can be formed in a desired state. The ratio of the diameter D 30 to the diameter D 10 is not limited to a specific value. The ratio D 10 / D 30 is, for example, 1.01 to 1.3, may be 1.05 to 1.2, or may be 1.05 to 1.1.

[0016] ​​​​As described above, in the ventilation component 1a, the inner diameter of the outer member 30 is larger than the outer diameter of the inner member 10 between the first contact portion 5c in the axial direction of the inner member 10 and the other opening 14, and a gap 34 exists. For example, in order to fix the ventilation component 1a to the projection 2p, the projection 2p is inserted into the inside of the inner member 10. The outer diameter of the projection 2p is larger than the inner diameter of the inner member 10. In this case, since the inner member 10 contains an elastic material, the inner member 10 deforms due to the projection 2p so that the inner diameter of the inner member 10 becomes larger. Along with this deformation, the outer diameter of the inner member 10 also tends to increase. If the inner diameter of the outer member 30 is less than or equal to the outer diameter of the inner member 10 between the first contact portion 5c in the axial direction of the inner member 10 and the other opening 14, the inner member 10 will experience a large compressive stress between the projection 2p and the outer member 30. As a result, a large force will be required to insert the projection 2p into the inside of the inner member 10. However, in the ventilation component 1a, the inner diameter of the outer member 30 is larger than the outer diameter of the inner member 10 between the first contact portion 5c in the axial direction of the inner member 10 and the other opening 14. Therefore, when the projection 2p is inserted into the inner member 10, a portion of the deformed inner member 10 is accepted into the gap 34. As a result, the inner member 10 is less likely to experience large compressive stress between the projection 2p and the outer member 30, and the force required to insert the projection 2p into the inner member 10 is reduced.

[0017] The difference ΔD obtained by subtracting the outer diameter of the internal member 10 from the inner diameter of the external member 30 between the first contact portion 5c of the internal member 10 in the axial direction and the other opening 14 is not limited to a specific value. The difference ΔD is, for example, 0.1 mm or more and 1.0 mm or less. This makes it easier to resolve problems associated with deformation of the internal member 10 when fixing the ventilation component 1a to the cylindrical projection 2p of the housing 2a.

[0018] The difference ΔD may be 0.2 mm or more, or 0.3 mm or more. The difference ΔD may be 0.9 mm or less, or 0.8 mm or less.

[0019] Figure 5 is a schematic perspective cross-sectional view showing the forces acting when a ventilation component 1x according to a reference example is attached to a projection 2p of the housing 2a. The ventilation component 1x is configured similarly to the ventilation component 1a, except that it does not have a protrusion 31p. When the ventilation component 1x is attached to the projection 2p, the internal member 10 deforms such that its inner diameter increases due to the projection 2p. As a result of this deformation, the outer diameter of the internal member 10 increases, and the portion of the internal member 10 that forms the first contact portion 5c also tends to deform outward in a direction perpendicular to the axis Ax. If the rigidity of the external member 30 is higher than that of the internal member 10, the external member 30 presses against the portion of the internal member 10 that forms the first contact portion 5c, suppressing the outward deformation of the portion of the internal member 10 that forms the first contact portion 5c in a direction perpendicular to the axis Ax. The compressive force exerted by the external member 30 as it tries to press against the portion of the internal member 10 that forms the first contact portion 5c causes a force that tightens the projection 2p. The first contact point 5c is center C 10 If positioned between the projection 2p and one of the openings 13, an upward force is likely to act on the internal member 10 near the tip of the projection 2p, and after being attached to the projection 2p, the ventilation component 1x may move away from the projection 2p.

[0020] On the other hand, with respect to the ventilation component 1a, as shown in Figure 3, the external member 30 has a protrusion 31p that forms the first contact portion 5c, and a gap 30g exists around the protrusion 31p. Therefore, when the ventilation component 1a is attached to the projection 2p, even if the internal member 10 deforms so that its inner diameter increases due to the projection 2p, the deformed portion is accepted by the gap 30g, and the compressive force that the external member 30 exerts on the portion of the internal member 10 that forms the first contact portion 5c is reduced. As a result, it is difficult for the internal member 10 to be pushed up near the tip of the projection 2p, and it is easier to prevent the ventilation component 1a from moving away from the projection 2p after it has been attached to the projection 2p.

[0021] The dimensions of the projection 31p of the internal member 10 around the axis Ax are not limited to a specific value. For example, in a plane perpendicular to the axis Ax of the internal member 10, the pair of straight lines connecting both ends of the projection 31p of the internal member 10 around the axis Ax to the axis Ax form an angle θ of 20° or less. With such a configuration, the compressive force exerted by the external member 30 on the portion of the internal member 10 that forms the first contact portion 5c is reduced, making it easier to prevent the ventilation component 1x from moving away from the projection 2p after being attached to the projection 2p. The angle θ may be 15° or less, or 10° or less. The angle θ is, for example, 5° or more.

[0022] The external member 30 is provided with, for example, a plurality of protrusions 31p. The plurality of protrusions 31p are arranged, for example, at equal intervals around the axis Ax. With such a configuration, in the ventilation component 1a, the axis of the external member 30 is more likely to be parallel to the axis Ax of the internal member 10, and when attaching the ventilation component 1a to the projection 2p of the housing 2a while gripping the external member 30, it is easier to attach the ventilation component 1a to the projection 2p of the housing 2a in the desired state.

[0023] The shape of the protruding portion 31p is not limited to a specific shape. For example, the protruding portion 31p has a rectangular contour in a cross-sectional view where the cutting plane is a plane perpendicular to the axis Ax of the internal member 10. With such a configuration, the external member 30 can be easily manufactured by molding.

[0024] As shown in Figure 2A, the closed pipe structure of the external member 30 has side walls 31 and a bottom wall 32. The side walls 31 extend along the axis Ax. The bottom wall 32 extends in a direction perpendicular to the axis Ax. A corner is formed where the bottom wall 32 and the side walls 31 intersect.

[0025] Typically, the ventilation membrane 20 is covered by a bottom wall 32. The bottom wall 32 is positioned, for example, away from the ventilation membrane 20 in the axial direction of the ventilation component 1a. As a result, a space 36 is formed between the bottom wall 32 and the ventilation membrane 20. Ventilation occurs as gas passes through the space 36.

[0026] As shown in Figures 2A and 2B, the internal member 10 has, for example, a central projection 11. The central projection 11 is formed on the outer circumferential surface of the internal member 10 at a position closer to the other opening 14 than the first contact portion 5c in the axial direction of the internal member 10. The central projection 11 protrudes in a direction perpendicular to the axis Ax of the internal member 10. With this configuration, it is easy to define the boundary between the portion forming the first contact portion 5c and the other portions of the internal member 10.

[0027] As shown in Figures 2A, 2B, and 3, the external member 30 has a protective wall 31n. When the external member 30 is viewed in plan along the axis Ax of the internal member 10, the protective wall 31n extends in a direction parallel to the axis Ax at a position closer to the axis Ax than the outermost end of the external member 30 in a direction perpendicular to the axis Ax. The protective wall 31n protects the first contact portion 5c. With this configuration, the first contact portion 5c is protected by the protective wall 31n, and the first contact portion 5c is more easily maintained in the desired state.

[0028] The protective wall 31n overlaps with the central projection 11 in a direction perpendicular to the axis Ax, for example. With this configuration, the protective wall 31n positions the internal member 10 and the external member 30 in the axial direction. This allows, for example, the distance between the bottom wall 32 of the external member 30 and the ventilation membrane 20 to be adjusted to a desired value. As shown in Figure 2A, for example, the end of the protective wall 31n in the axial direction faces the central projection 11 of the internal member 10.

[0029] The protective wall 31n has, for example, an arc-shaped contour in a plan view. The projection 31p is, for example, integrally formed with the protective wall 31n and is positioned at the center of the protective wall 31n around the axis Ax of the internal member 10.

[0030] The external member 30 includes, for example, a plurality of protective walls 31n corresponding to a plurality of protrusions 31p. The plurality of protective walls 31n are arranged, for example, at equal intervals around the axis Ax.

[0031] As shown in Figure 3, the central projection 11 is formed around the entire circumference of the outer surface of the open pipe structure of the internal member 10. In other words, the central projection 11 is formed in an annular shape. With this configuration, regardless of the arrangement of the internal member 10 around the axis Ax, the boundary between the portion forming the first contact portion 5c and the other portions of the internal member 10 is easily determined.

[0032] As shown in Figures 2A and 2B, the external member 30 has, for example, a latching portion 33. The latching portion 33 is formed on the inner circumferential surface of the external member 30 and latches onto the central projection 11. This prevents the external member 30 from detaching from the internal member 10 in the ventilation component 1a.

[0033] As shown in Figure 2A, the latching portion 33 protrudes toward the axis Ax in a direction perpendicular to the axis Ax, for example. The external member 30 has, for example, a plurality of latching portions 33. The plurality of latching portions 33 are arranged, for example, at predetermined intervals around the axis Ax. The plurality of latching portions 33 are arranged, for example, at equal intervals around the axis Ax. The latching portions 33 may be formed in an annular shape on the inner circumferential surface of the closed pipe structure of the external member 30, for example.

[0034] As shown in Figure 2B, the latching portion 33 has, for example, an inclined surface 33s. The distance between the inclined surface 33s and the outer circumferential surface of the internal member 10 at a specific position in the axial direction is greater than the distance between the inclined surface 33s and the outer circumferential surface of the internal member 10 at a position closer to the central projection 11 than the specific position in the axial direction. With this configuration, the frictional force between the central projection 11 and the latching portion 33 tends to be small when attaching the internal member 10 inside the external member 30. For this reason, it is easier to attach the internal member 10 inside the external member 30.

[0035] As shown in Figure 2A, the end face of the central projection 11 in the direction perpendicular to the axis Ax has, for example, a tapered surface 11t and a columnar surface 11p. The columnar surface 11p is formed closer to the other opening 14 than the tapered surface 11t. The diameter of the tapered surface 11t decreases toward the one opening 13. The ratio (Lt / Lz) of the length Lt of the portion forming the tapered surface 11t to the total length Lz of the central projection 11 in the axial direction is, for example, 0.2 to 0.8. For example, the internal member 10 is attached inside the external member 30 by moving the internal member 10 and the external member 30 relatively so that the distance between the external member 30 and the internal member 10 decreases in the axial direction. At this time, the portion of the external member 30 near the latching portion 33 deforms outward in the direction perpendicular to the axis Ax. When Lt / Lz is within the above range, the amount of deformation around the latching portion 33 does not change abruptly when the internal member 10 is installed inside the external member 30. Therefore, it is easier to install the internal member 10 inside the external member 30. In addition, the length of the columnar surface 11p in the axial direction tends to be shorter, so the period during which the amount of deformation around the latching portion 33 is at its maximum when the internal member 10 is installed inside the external member 30 is shortened.

[0036] As shown in Figures 1C and 2A, the ventilation component 1a has, for example, a ventilation hole 35. The ventilation hole 35 overlaps, for example, at least a portion of the first contact portion 5c in the axial direction of the internal member 10. With this configuration, ventilation can be performed by the ventilation hole 35 even if the ventilation passage formed between the outer circumferential surface of the internal member 10 and the inner circumferential surface of the external member 30 is not wide between the first contact portion 5c in the axial direction of the internal member 10 and the other opening 14.

[0037] The ventilation holes 35 are formed, for example, by penetrating the side wall 31. In other words, the ventilation holes 35 connect the inner circumferential surface of the side wall 31 with the outer circumferential surface of the side wall 31. The ventilation holes 35 are formed, for example, in a position closer to the bottom wall 32 than to the protruding portion 11 in the axial direction.

[0038] The ventilation holes 35 may be formed, for example, through the bottom wall 32. In other words, the ventilation holes 35 may be formed to connect the inner circumferential surface of the bottom wall 32 with the outer circumferential surface of the bottom wall 32. The ventilation holes 35 may be formed, for example, through the side wall 31 and the bottom wall 32. In other words, the ventilation holes 35 may be formed to connect the inner circumferential surface of the side wall 31 with the outer circumferential surface of the bottom wall 32, or to connect the inner circumferential surface of the bottom wall 32 with the outer circumferential surface of the side wall 31. The ventilation holes 35 may be formed as through holes or as slits.

[0039] As shown in Figure 1C, the ventilation hole 35 is formed such that, for example, at least one of the internal member 10 and the ventilation membrane 20 cannot be seen from the ventilation hole 35. In other words, the ventilation hole 35 is formed such that, when looking inside the external member 30 from outside the external member 30 through the ventilation hole 35, at least one of the internal member 10 and the ventilation membrane 20 cannot be seen. In this case, for example, the inside of the external member 30 is observed in a direction perpendicular to the opening in the ventilation hole 35 that is in contact with the outer circumferential surface of the external member 30. With this configuration, even if foreign matter passes through the ventilation hole 35 from outside the external member 30, it is easier to prevent damage to at least one of the internal member 10 and the ventilation membrane 20 by such foreign matter.

[0040] As shown in Figures 1B and 3, the side wall 31 has, for example, an outer side wall 31g and a protective wall 31n. The outer side wall 31g includes, for example, a portion 31b of the external member 30 facing the central projection 11 and a plurality of ribs 31r. The plurality of ribs 31r are arranged at predetermined intervals around axis Ax between portion 31b and the bottom wall 32 in the axial direction. Typically, the plurality of ribs 31r are arranged at equal intervals around axis Ax. The protective wall 31n is located closer to axis Ax than the outer side wall 31g in a direction perpendicular to axis Ax. The protective wall 31n is formed between portion 31b and the bottom wall 32 in the axial direction.

[0041] Multiple ribs 31r and multiple protective walls 31n are arranged alternately, for example, around the axis Ax. As a result, as shown in Figure 1A, recesses are formed in the external member 30 at predetermined intervals around the axis Ax. For example, the ends of the ribs 31r overlap with the ends of the protective walls 31n around the axis Ax. As a result, ventilation holes 35 are formed by the gaps between the ends of the ribs 31r and the ends of the protective walls 31n around the axis Ax. With this configuration, the internal member 10 and the ventilation membrane 20 can be properly protected by the side walls 31, and it is easy to form wide ventilation holes 35.

[0042] The elastic material included in the internal component 10 is not limited to a specific elastic material. The elastic material is, for example, an elastomer (elastic resin). The elastomer may also be rubber. Examples of elastomers include nitrile rubber (NBR), ethylene-propylene rubber (EPDM), silicone rubber, fluororubber, acrylic rubber, hydrogenated rubber, or various thermoplastic elastomers.

[0043] The material of the external member 30 is not limited to a specific material. The material of the external member 30 is, for example, a resin. The resin is, for example, a thermoplastic resin or the elastomer described above. Thermoplastic resins include, for example, polyamide (PA) such as nylon, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), polycarbonate (PC), polypropylene (PP), or polyphenylene ether (PPE). The material of the external member 30 may be the same type of material as the elastic material contained in the internal member 10, or it may be a different type of material.

[0044] The resin contained in the internal member 10 and the external member 30 may contain pigments such as carbon black and titanium white; reinforcing fillers such as glass particles and glass fibers; and additives such as water repellents.

[0045] The permeable membrane 20 is not limited to a specific permeable membrane as long as it has the desired permeability. The permeable membrane 20 may be a single layer or a multilayer membrane. If the permeable membrane 20 is a multilayer membrane, each layer may be one selected from the group consisting of porous membranes, nonwoven fabrics, cloths, and meshes. The permeable membrane 20 may include a porous membrane and a nonwoven fabric, or it may include at least one of cloths and meshes and a porous membrane, or it may include multiple nonwoven fabrics. The permeable membrane 20 is typically composed of an organic polymer material (resin). The material of the porous membrane is, for example, a fluororesin. As the fluororesin, for example, polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, or tetrafluoroethylene-ethylene copolymer can be used. The material of the porous membrane may be a polyolefin such as a polymer or copolymer of individual monomers such as ethylene, propylene, and 4-methylpentene-1,1-butene. The porous membrane may be a porous membrane of nanofibers such as polyacrylonitrile, nylon, or polylactic acid. The porous membrane can be manufactured by known stretching or extraction methods. The materials for the nonwoven fabric, cloth, and mesh are, for example, polyester such as polyethylene terephthalate, polyolefins such as polyethylene and polypropylene, nylon, aramid, or ethylene vinyl acetate copolymer.

[0046] The breathable membrane 20 preferably includes a PTFE porous membrane. The PTFE porous membrane can ensure breathability even in a small area and effectively prevent the entry of foreign matter. The PTFE porous membrane may be laminated on a breathable support material such as a nonwoven fabric.

[0047] The thickness of the permeable membrane 20 is not limited to a specific thickness. For example, the thickness of the permeable membrane 20 is between 1 μm and 5 mm. The air permeability of the permeable membrane 20 is, for example, 0.1 to 300 seconds / 100 mL when measured in accordance with the air permeability measurement method B (Gurley method) specified in Japanese Industrial Standard JIS L1096.

[0048] The permeable film 20 may be treated with a liquid-repellent coating as needed. The liquid-repellent coating is performed, for example, by forming a liquid-repellent film on the permeable film 20 containing a fluorine-based surface modifier having a perfluoroalkyl group. The formation of the liquid-repellent film is not limited to any particular method. The liquid-repellent film can be formed by coating the porous resin film with a solution or dispersion of a fluorine-based surface modifier having a perfluoroalkyl group using methods such as air spraying, electrostatic spraying, dip coating, spin coating, roll coating, curtain flow coating, or impregnation. Alternatively, the liquid-repellent film may be formed by electrodeposition coating or plasma polymerization.

[0049] At least a portion of the surface of at least one of the internal member 10 and the external member 30 may be treated with a liquid-repellent coating. The liquid-repellent coating can be performed by the method described above, electrodeposition coating, or film formation by plasma polymerization, etc., as a liquid-repellent coating method for the breathable film 20.

[0050] The ventilation membrane 20 is, for example, bonded to the axial end face of the internal member 10. The ventilation membrane 20 may also be welded to this end face. Methods of welding include heat welding, ultrasonic welding, and laser welding. Alternatively, when molding the internal member 10, the ventilation membrane 20 may be placed in a predetermined position inside the mold for molding, and resin may be poured into the mold to perform insert molding, thereby attaching the ventilation membrane 20 to its end face. The ventilation membrane 20 may also be attached to its end face by double-sided tape.

[0051] Using the ventilation component 1a, for example, a ventilation structure 3a as shown in Figure 4 can be provided. The ventilation structure 3 comprises the ventilation component 1a and a housing 2a. The housing 2a has a cylindrical projection 2p on its outer circumferential surface, and the ventilation component 1a is fixed to the projection 2p. Specifically, the ventilation component 1a is inserted into the interior of the internal member 10 from the other opening 14 of the internal member 10, and is fixed to the projection 2p in a specific state in which the inner circumferential surface 12 of the internal member 10 and the outer circumferential surface 2q of the projection 2p are in contact. The inner diameter of the open pipe structure of the internal member 10 is smaller than the outer diameter of the projection 2p. Also, the inner circumferential surface 12 of the internal member 10 is typically formed of an elastic material. Therefore, in a specific state, the portion of the internal member 10 that is in contact with the outer circumferential surface 2q of the projection 2p deforms to match the outer diameter of the projection 2p. This firmly fixes the ventilation component 1a to the projection 2p.

[0052] As shown in Figure 4, with the ventilation structure 3a, as indicated by the dashed arrows, gas passes through the ventilation membrane 20 between the internal space 2u and the external space 2v of the housing 2a, thereby ventilating the space. For example, the space 36 and the ventilation holes 35 are included in the ventilation passages for this ventilation.

[0053] As shown in Figure 4, an annular groove 2m is formed around the projection 2p of the housing 2a. When the ventilation structure 3a is viewed in plan along the axis Ax, the outer diameter of the groove 2m is larger than the outer diameter of the ventilation component 1a. Therefore, when the ventilation component 1a is fixed to the projection 2p, a part of the ventilation component 1a is housed inside the groove 2m. With this configuration, the contact area between the inner circumferential surface 12 of the internal member 10 and the outer circumferential surface 2q of the projection 2p can be increased, making it easier to firmly fix the ventilation component 1a to the projection 2p. In addition, the apparent protruding length of the ventilation component 1a on the outer surface of the housing 2a can be reduced. It is not necessary for the groove 2m to be formed around the projection 2p in the housing 2a.

[0054] The material of the housing 2a is not limited to a specific material. The material of the housing 2a may be, for example, resin, metal, or a composite material thereof. Typically, the elastic modulus of the material forming the protrusion 2p in the housing 2a is higher than the elastic modulus of the elastic material contained in the internal member 20. The housing 2a is, for example, a housing for automotive electronic components such as lamps, inverters, converters, ECUs (Electronic Control Units), battery packs, radar, and cameras. The housing 2a may also be a housing for various electronic devices for home, medical, and office use.

[0055] The ventilation component 1a can be modified from various perspectives. The ventilation component 1a may be changed to the ventilation component 1b shown in Figure 6A, the ventilation component 1c shown in Figure 6B, the ventilation component 1d shown in Figure 6C, the ventilation component 1e shown in Figure 6D, the ventilation component 1f shown in Figure 6E, the ventilation component 1g shown in Figure 6F, or the ventilation component 1h shown in Figure 6G. The ventilation components 1b to 1h are configured similarly to the ventilation component 1a, except for parts that are specifically described. Components of ventilation components 1b to 1h that are identical or corresponding to components of ventilation component 1a are denoted by the same reference numerals, and detailed descriptions are omitted. The description of ventilation component 1a also applies to ventilation components 1b to 1h, to the extent that it does not technically contradict the description.

[0056] As shown in Figure 6A, in the ventilation component 1b, multiple protrusions 31p are formed on a single protective wall 31n. For example, a pair of protrusions 31p are formed on both ends of the protective wall 31n around the axis Ax. With this configuration, the axis Ax of the internal member 10 is less likely to tilt with respect to the axis of the external member 30, and the external member 30 is less likely to detach from the internal member 10.

[0057] As shown in Figure 6B, in the ventilation component 1c, the protruding portion 31p has a semicircular contour in a cross-sectional view where the cutting plane is perpendicular to the axis Ax of the internal member 10. With this configuration, the external member 30 can be easily manufactured by molding.

[0058] As shown in Figure 6C, in the ventilation component 1d, the protruding portion 31p has a triangular contour in a cross-sectional view where the cutting plane is perpendicular to the axis Ax of the internal member 10. In this case as well, the external member 30 can be easily manufactured by molding.

[0059] As shown in Figure 6D, in the ventilation component 1e, instead of the protrusion 31p, the internal member 10 has a protrusion 10p that forms the first contact portion 5c. The protrusion 10p is formed on the outer circumferential surface of the internal member 10. With this configuration, it is difficult for the internal member 10 to be pushed up near the tip of the projection 2p, and it is easier to prevent the ventilation component 1x from moving away from the projection 2p after it has been attached to the projection 2p.

[0060] In the ventilation component 1e, the internal member 10 has, for example, a plurality of protrusions 10p. The plurality of protrusions 10p are arranged, for example, at equal intervals around the axis Ax. The ventilation component 1e has a plurality of protective walls 31n. One protrusion 10p is formed for each protective wall 31n.

[0061] The protruding portion 10p has a rectangular contour in a cross-sectional view where the cutting plane is perpendicular to the axis Ax. With this configuration, the internal member 10 can be easily manufactured by molding.

[0062] As shown in Figure 6E, in the ventilation component 1f, multiple protrusions 10p are formed on a single protective wall 31n. For example, around the axis Ax, a pair of protrusions 10p are formed to contact both ends of the protective wall 31n. With this configuration, the axis Ax of the internal member 10 is less likely to tilt with respect to the axis of the external member 30, and the external member 30 is less likely to detach from the internal member 10.

[0063] As shown in Figure 6F, in the ventilation component 1g, the protruding portion 10p has a semicircular contour in a cross-sectional view where the cutting plane is perpendicular to the axis Ax. In this case as well, the internal component 10 can be easily manufactured by molding.

[0064] As shown in Figure 6G, in the ventilation component 1h, the protruding portion 10p has a triangular contour in a cross-sectional view taken with a plane perpendicular to the axis Ax as the cutting plane. In this case as well, the internal component 10 can be easily manufactured by molding.

[0065] The ventilation component 1a may be modified as shown in the ventilation component 1i in Figures 7A and 7B. The ventilation component 1i is configured similarly to the ventilation component 1a, except for parts that are not specifically described. Components of the ventilation component 1i that are the same as or correspond to components of the ventilation component 1a are given the same reference numerals, and detailed descriptions are omitted. Descriptions of the ventilation component 1a also apply to the ventilation component 1i, to the extent that they do not technically contradict each other.

[0066] As shown in Figures 7A and 7B, in the ventilation component 1i, the external member 30 has, for example, four protrusions 31p around the axis Ax of the internal member 10. The four protrusions 31p are arranged at equal intervals around the axis Ax. The four protrusions 31p project toward the axis Ax from the inner circumferential surface of the annular side wall 31. The first contact portion 5c is formed away from one of the openings 13 in the axial direction of the internal member 10. The outer circumferential surface of the internal member 10 that is in contact with one of the openings 13 has a tapered surface. With such a configuration, the structure of the ventilation component 1i tends to be simple.

[0067] Using the ventilation component 1i, for example, a ventilation structure 3b can be provided. In the ventilation structure 3b, the ventilation component 1i is attached to the projection 2p of the housing 2b. The housing 2b is configured in the same way as the housing 2a, except that it does not have a groove 2m. In the ventilation structure 3b, the space between the projections 31p around the axis Ax functions as a ventilation passage.

[0068] The ventilation component 1i may be modified as shown in Figure 7C for ventilation component 1k and Figure 7D for ventilation component 1m. Ventilation components 1k and 1m are configured similarly to ventilation component 1i, except for parts that are not specifically described. Components of ventilation components 1k and 1m that are the same as or correspond to components of ventilation component 1i are given the same reference numerals, and detailed descriptions are omitted. The descriptions of ventilation components 1a and 1i also apply to ventilation components 1k and 1m, to the extent that they do not technically contradict each other.

[0069] As shown in Figure 7C, in the ventilation component 1k, the external member 30 has six protrusions 31p around the axis Ax of the internal member 10. By assembling the ventilation component 1k to the housing 2b, a ventilation structure 3c can be provided. As shown in Figure 7D, in the ventilation component 1m, the external member 30 has eight protrusions 31p around the axis Ax of the internal member 10. By assembling the ventilation component 1m to the housing 2b, a ventilation structure 3d can be provided. The ventilation component 1i may be modified so that the number of protrusions 31p on the external member 30 is an integer of 2 or more other than 4, 6, and 8.

[0070] The ventilation component 1a may be modified as shown in the ventilation component 1n in Figures 8A and 8B. The ventilation component 1n is configured similarly to the ventilation component 1a, except for parts that are not specifically described. Components of the ventilation component 1n that are the same as or correspond to components of the ventilation component 1a are given the same reference numerals, and detailed descriptions are omitted. Descriptions of the ventilation component 1a also apply to the ventilation component 1n, to the extent that they do not technically contradict each other.

[0071] In the ventilation component 1n, the internal member 10 is provided with, for example, four protrusions 10p around the axis Ax of the internal member 10. The four protrusions 10p are arranged at equal intervals around the axis Ax. The four protrusions 10p contact the inner circumferential surface of the annular side wall 31 to form a first contact portion 5c. In the ventilation component 1n, the first contact portion 5c is formed away from one of the openings 13 in the axial direction of the internal member 10. On the outer circumferential surface of the internal member 10, a tapered surface is formed between the first contact portion 5c and one of the openings 13 in the axial direction of the internal member 10. With such a configuration, the structure of the ventilation component 1n tends to be simple.

[0072] Using the ventilation component 1n, for example, a ventilation structure 3e can be provided. In the ventilation structure 3e, the ventilation component 1n is attached to the projection 2p of the housing 2b. In the ventilation structure 3e, the space between the projections 10p around the axis Ax functions as a ventilation passage.

[0073] The ventilation component 1n may be modified as shown in Figure 8C, as shown in the ventilation component 1o. The ventilation component 1o is configured similarly to the ventilation component 1n, except for the parts that are not specifically described. Components of the ventilation component 1o that are the same as or correspond to components of the ventilation component 1n are given the same reference numerals, and detailed descriptions are omitted. The descriptions of the ventilation components 1a and 1n also apply to the ventilation component 1o, to the extent that they do not technically contradict each other.

[0074] As shown in Figure 8C, in the ventilation component 1o, the internal member 10 has eight protrusions 10p around the axis Ax of the internal member 10. By assembling the ventilation component 1o to the housing 2b, a ventilation structure 3f can be provided. In the ventilation component 1n, the number of protrusions 31p on the external member 30 may be changed to an integer of 2 or more other than 4 and 8. [Examples]

[0075] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples.

[0076] <Example 1> A ventilation component according to Embodiment 1, having the same configuration as ventilation component 1a, was manufactured. The axial dimension of the ventilation component according to Embodiment 1 was approximately 7 mm. The length of the internal member in the axial direction of the ventilation component according to Embodiment 1 was 5 mm. The inner diameter of the internal member of the ventilation component was 7.4 mm. The outer diameter D of the part of the internal member that forms the contact area between the internal member and the external member. 10 It was 9.2 mm. The diameter D of the inscribed circle that is inscribed within the portion of the external member that forms the contact area. 30 The diameter was 9 mm. The external member of the ventilation component according to Example 1 had four protrusions that formed contact points, and in a plane perpendicular to the axis Ax of the internal member, a pair of straight lines connecting both ends of the protrusions around the axis Ax of the internal member to the axis Ax formed an angle θ of 11° or less. The ventilation component was attached to a housing A having a cylindrical projection with a height of 3.7 mm, such that the projection was completely covered by the ventilation component. In this attachment, the projection was inserted into the interior of the internal member. The outer diameter of the projection in housing A was 8 mm, and the outer circumferential surface of the tip of the projection was formed to have a radius of curvature of 0.5 mm. In this way, the ventilation structure according to Example 1 was obtained.

[0077] <Example 2> A ventilation component according to Example 1 was attached to a housing B having a cylindrical projection with a height of 3.7 mm, such that the projection was completely covered by the ventilation component. In this attachment, the projection was inserted into the interior of the internal member. The outer diameter of the projection in housing B was 8.4 mm, and the outer circumferential surface of the tip of the projection was formed to have a radius of curvature of 0.5 mm. In this way, the ventilation structure according to Example 2 was obtained.

[0078] <Comparative Example 1> A ventilation component according to Comparative Example 1 was manufactured in the same manner as in Example 1, except that the external component did not have four protrusions. The outer diameter D of the portion of the internal component that forms the contact area between the internal component and the external component. 10 It was 10.6 mm. The diameter D of the inscribed circle that is inscribed within the portion of the external member that forms the contact area. 30The diameter was 10 mm. Except for using the ventilation component according to Comparative Example 1, the ventilation component according to Comparative Example 1 was attached to housing A in the same manner as in Example 1, and a ventilation structure according to Comparative Example 1 was obtained.

[0079] <Comparative Example 2> Except for using the ventilation component according to Comparative Example 1, the ventilation component according to Comparative Example 1 was attached to housing B in the same manner as in Example 2, thereby obtaining the ventilation structure according to Comparative Example 2.

[0080] (Thermal shock test) Twelve ventilation structures were prepared for each of the following: the ventilation structure according to Example 1, the ventilation structure according to Example 2, the ventilation structure according to Comparative Example 1, and the ventilation structure according to Comparative Example 2. Thermal shock tests were conducted on each ventilation structure by varying the ambient temperature within the range of -40°C to 125°C. In the thermal shock test, the ambient temperature of the ventilation structure was adjusted so that one temperature change cycle occurred over one hour. In one temperature change cycle, the ambient temperature of the ventilation structure changed from 125°C to -40°C and then returned to 125°C. In the thermal shock test, 300 temperature changes were generated over 300 hours. At predetermined timings during the thermal shock test, the distance from the base of the protrusion to the top of the ventilation component was measured, and the amount of change in each ventilation structure was determined by subtracting the distance from the base of the protrusion to the top of the ventilation component before the start of the thermal shock test from the measured value, and the average amount of change for the 12 ventilation structures was calculated. Figure 9 shows the relationship between the average amount of change and the test time for the ventilation structures according to Example 1 and Comparative Example 1. Figure 10 shows the relationship between the average value of the change in the ventilation structure for Example 2 and Comparative Example 2 and the test time.

[0081] As shown in Figures 9 and 10, the average value of the change was smaller in the ventilation structures of Examples 1 and 2, which used the ventilation component of Example 1, compared to the ventilation structures of Comparative Examples 1 and 2, which used the ventilation component of Comparative Example 1. It is understood that the ventilation component of Example 1 is less likely to move away from the protrusion of the housing after being attached, compared to the ventilation component of Comparative Example 1.

[0082] The first aspect of the present invention is, A ventilation component, An internal member containing an elastic material and having an open tube structure, A ventilation membrane covering one of the openings of the internal member, It comprises an external member having a closed pipe structure, The internal member is fixed to the external member such that it is inserted into the external member and a portion of the outer circumferential surface of the internal member is elastically deformed to form a first contact portion with a portion of the inner circumferential surface of the external member. The ventilation component is fixed in such a state that a projection protruding cylindrically from the outer surface of the housing toward the edge of a ventilation opening that connects the internal space and the external space of the housing is inserted into the interior of the internal member from the other opening of the internal member, and the inner circumferential surface of the internal member is elastically deformed to form a second contact portion with the outer circumferential surface of the projection. The first contact portion is positioned between the center in the axial direction of the portion of the internal member that overlaps with the external member in the axial direction of the internal member and the one opening. The inner diameter of the external member is greater than the outer diameter of the internal member in the axial direction between the first contact portion and the other opening of the internal member. The internal member and the external member have a projection formed on the inner circumferential surface of the external member or the outer circumferential surface of the internal member that forms the first contact portion. Around the axis of the internal member, a gap exists between the inner surface of the external member and the outer surface of the internal member around the protruding portion. We provide ventilation components.

[0083] A second aspect of the present invention is, in the first aspect, The present invention provides a ventilation component in which, in a plane perpendicular to the axis of the internal member, a pair of straight lines connecting both ends of the protrusions around the axis of the internal member to the axis form an angle of 20° or less.

[0084] A third aspect of the present invention is that, in the first or second aspect, The aforementioned protrusion is formed on the inner circumferential surface of the external member. We provide ventilation components.

[0085] A fourth aspect of the present invention is that, in the first or second aspect, The aforementioned protrusion is formed on the outer circumferential surface of the internal member. We provide ventilation components.

[0086] The fifth aspect of the present invention is that in any one of the first to fifth aspects, The internal member has a central projection formed on its outer circumferential surface at a position closer to the other opening than the first contact portion in the axial direction of the internal member, and projecting in a direction perpendicular to the axis of the internal member. We provide ventilation components.

[0087] Aspect 6 of this disclosure is as described in Aspect 5, The external member, when viewed in plan along the axis of the internal member, extends in a direction parallel to the axis at a position closer to the axis than the outermost end in the direction perpendicular to the axis, and has a protective wall that protects the first contact portion. The protective wall overlaps the central projection in a direction perpendicular to the axis. We provide ventilation components.

[0088] Aspect 7 of this disclosure is, in Aspect 5 or Aspect 6, The external member has a hooking portion formed on its inner circumferential surface for engaging the central protrusion. We provide ventilation components.

[0089] Aspect 8 of this disclosure is that, in any one of Aspects 1 through 7, The external member has ventilation holes that overlap at least a portion of the first contact portion in the axial direction of the internal member. We provide ventilation components.

[0090] Aspect 9 of this disclosure is: The casing and An internal member containing an elastic material and having an open tube structure, A ventilation membrane covering one of the openings of the internal member, It comprises an external member having a closed pipe structure, The internal member is fixed to the external member such that it is inserted into the external member and a portion of the outer circumferential surface of the internal member is elastically deformed to form a first contact portion with a portion of the inner circumferential surface of the external member. The housing has a projection on its outer surface that protrudes in a cylindrical shape toward the edge of a ventilation opening that connects the internal space and the external space of the housing, The projection is inserted into the interior of the internal member through the other opening of the internal member, and the inner circumferential surface of the internal member is elastically deformed and fixed in a state in which it forms a second contact portion with the outer circumferential surface of the projection. The first contact portion is positioned between the center in the axial direction of the portion of the internal member that overlaps with the external member in the axial direction of the internal member and the one opening. The inner diameter of the external member is greater than the outer diameter of the internal member in the axial direction between the first contact portion and the other opening of the internal member. The internal member and the external member have a projection formed on the inner circumferential surface of the external member or the outer circumferential surface of the internal member that forms the first contact portion. Around the axis of the internal member, a gap exists between the inner surface of the external member and the outer surface of the internal member around the protruding portion. Provides a ventilated structure. [Explanation of symbols]

[0091] 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h Ventilation parts 1i, 1k, 1m, 1n, 1o ventilation parts 2a, 2b enclosure 2p protrusion 5c First contact part 6c Second contact part 10 Internal components 10p protrusion 11 Central protrusion 20. Ventilated membrane 30 External components 30g gap 31p Protrusion 33 Hanging section 35 through hole

Claims

1. A ventilation component, An internal member containing an elastic material and having an open tube structure, A ventilation membrane covering one of the openings of the internal member, It comprises an external member having a closed pipe structure, The internal member is fixed to the external member such that it is inserted into the external member and a portion of the outer circumferential surface of the internal member is elastically deformed to form a first contact portion with a portion of the inner circumferential surface of the external member. The ventilation component is fixed in such a state that a projection protruding cylindrically from the outer surface of the housing toward the edge of a ventilation opening that connects the internal space and the external space of the housing is inserted into the interior of the internal member from the other opening of the internal member, and the inner circumferential surface of the internal member is elastically deformed to form a second contact portion with the outer circumferential surface of the projection. The first contact portion is positioned between the center in the axial direction of the portion of the internal member that overlaps with the external member in the axial direction of the internal member and the one opening. The inner diameter of the external member is greater than the outer diameter of the internal member in the axial direction between the first contact portion and the other opening of the internal member. The internal member and the external member have a projection formed on the inner circumferential surface of the external member or the outer circumferential surface of the internal member that forms the first contact portion. Around the axis of the internal member, a gap exists between the inner surface of the external member and the outer surface of the internal member around the protruding portion. Ventilation components.

2. The ventilation component according to claim 1, wherein, in a plane perpendicular to the axis of the internal component, a pair of straight lines connecting both ends of the protrusion around the axis of the internal component to the axis form an angle of 20° or less.

3. The aforementioned protrusion is formed on the inner circumferential surface of the external member. The ventilation component according to claim 1.

4. The aforementioned protrusion is formed on the outer circumferential surface of the internal member. The ventilation component according to claim 1.

5. The ventilation component according to claim 1, wherein the internal member has a central projection formed on the outer circumferential surface of the internal member at a position closer to the other opening than the first contact portion in the axial direction of the internal member, and projecting in a direction perpendicular to the axis of the internal member.

6. The external member, when viewed in plan along the axis of the internal member, extends in a direction parallel to the axis at a position closer to the axis than the outermost end in the direction perpendicular to the axis, and has a protective wall that protects the first contact portion. The protective wall overlaps the central projection in a direction perpendicular to the axis. The ventilation component according to claim 5.

7. The external member has a hooking portion formed on its inner circumferential surface for engaging the central protrusion. The ventilation component according to claim 5.

8. The external member has ventilation holes that overlap at least a portion of the first contact portion in the axial direction of the internal member. The ventilation component according to claim 1.

9. The casing and An internal member containing an elastic material and having an open tube structure, A ventilation membrane covering one of the openings of the internal member, It comprises an external member having a closed pipe structure, The internal member is fixed to the external member such that it is inserted into the external member and a portion of the outer circumferential surface of the internal member is elastically deformed to form a first contact portion with a portion of the inner circumferential surface of the external member. The housing has a projection on its outer surface that protrudes in a cylindrical shape toward the edge of a ventilation opening that connects the internal space and the external space of the housing, The projection is inserted into the interior of the internal member through the other opening of the internal member, and the inner circumferential surface of the internal member is elastically deformed and fixed in a state in which it forms a second contact portion with the outer circumferential surface of the projection. The first contact portion is positioned between the center in the axial direction of the portion of the internal member that overlaps with the external member in the axial direction of the internal member and the one opening. The inner diameter of the external member is greater than the outer diameter of the internal member in the axial direction between the first contact portion and the other opening of the internal member. The internal member and the external member have a projection formed on the inner circumferential surface of the external member or the outer circumferential surface of the internal member that forms the first contact portion. Around the axis of the internal member, a gap exists between the inner surface of the external member and the outer surface of the internal member around the protruding portion. Ventilated structure.

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