U.S. patent application number 12/086368 was filed with the patent office on 2010-09-09 for vent member and vent structure.
This patent application is currently assigned to NITTO DENKO CORPORATION. Invention is credited to Satoru Furuyama, Toshiki Yanagi.
Application Number | 20100227544 12/086368 |
Document ID | / |
Family ID | 38162702 |
Filed Date | 2010-09-09 |
United States Patent
Application |
20100227544 |
Kind Code |
A1 |
Furuyama; Satoru ; et
al. |
September 9, 2010 |
Vent Member and Vent Structure
Abstract
A vent structure 100A of the present invention includes a
housing 91 and a vent member 13A attached to an opening portion 91k
of the housing 91. The vent member 13A is provided with a support
body 11 having a through hole 11h to serve as a gas passage between
the interior and the exterior of the housing 91 and a gas permeable
membrane 6 fixed to the support body 11 so as to close the through
hole 11h. Assuming that a thickness direction of the gas permeable
membrane is a height direction, a height H.sub.1 of the support
body 11 from a second opening end face 11q (aligned with an outer
surface 91p of the housing 91) to a first opening end face 11p on
the other side is set to 4 mm or more.
Inventors: |
Furuyama; Satoru; (Osaka,
JP) ; Yanagi; Toshiki; (Osaka, JP) |
Correspondence
Address: |
HAMRE, SCHUMANN, MUELLER & LARSON, P.C.
P.O. BOX 2902
MINNEAPOLIS
MN
55402-0902
US
|
Assignee: |
NITTO DENKO CORPORATION
Ibaraki-shi, Osaka
JP
|
Family ID: |
38162702 |
Appl. No.: |
12/086368 |
Filed: |
October 12, 2006 |
PCT Filed: |
October 12, 2006 |
PCT NO: |
PCT/JP2006/320416 |
371 Date: |
June 11, 2008 |
Current U.S.
Class: |
454/339 |
Current CPC
Class: |
F21S 45/30 20180101;
F21V 31/03 20130101; F24F 2003/1435 20130101; H05K 5/0213
20130101 |
Class at
Publication: |
454/339 |
International
Class: |
F24F 7/00 20060101
F24F007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 14, 2005 |
JP |
2005-361092 |
Claims
1. A vent member to be attached to a housing that needs
ventilation, comprising: a support body having a through hole to
serve as a gas passage between the interior and the exterior of the
housing; and a gas permeable membrane fixed to the support body so
as to close the through hole, wherein: assuming that a thickness
direction of the gas permeable membrane is a height direction, the
support body is formed so that the through hole extends in the
height direction from one opening end face to the other opening end
face, and the height from the one opening end face to the other
opening end face is set to 4 mm or more.
2. The vent member according to claim 1, wherein the gas permeable
membrane is disposed on the one opening end face.
3. The vent member according to claim 1, wherein the support body
includes a cover forming a clearance between the gas permeable
membrane and itself while covering the gas permeable membrane on
the side opposite to the side that is attached to the housing.
4. The vent member according to claim 1, wherein the gas permeable
membrane is disposed in the through hole.
5. The vent member according to claim 4, wherein the height from
the other opening end face to the gas permeable membrane is set to
4 mm or more.
6. The vent member according to claim 4, wherein the gas permeable
membrane is fixed to the support body inside the through hole by
having its own peripheral portion integrated with the resin of
which the support body is composed.
7. The vent member according to claim 6, wherein the peripheral
portion of the gas permeable membrane is embedded into the support
body.
8. The vent member according to claim 7, wherein: the gas permeable
membrane includes a main membrane body including a resin porous
membrane and a gas-permeable reinforcement member attached to the
main membrane body so as to cover at least one of the principal
surfaces of the main membrane body, and a peripheral portion of the
main membrane body and that of the reinforcement member are both
embedded into the support body.
9. The vent member according to claim 8, wherein the reinforcement
member includes a mesh made of metal or resin.
10. The vent member according to claim 1, wherein: the support body
includes a stepped portion formed along an entire circumference
inside the through hole, and a cross-sectional area of the through
hole with respect to a lateral direction perpendicular to the
height direction changes discontinuously at the stepped portion,
and the gas permeable membrane is disposed on the stepped
portion.
11. The vent member according to claim 10, wherein: the gas
permeable membrane includes a main membrane body including a resin
porous membrane and a gas-permeable reinforcement member attached
to the main membrane body so as to cover at least one of the
principal surfaces of the main membrane body, and the gas permeable
membrane is fixed to the support body so that the reinforcement
member is in contact with a seating face of the stepped
portion.
12. The vent member according to claim 10, wherein the
cross-sectional area of the through hole with respect to the
lateral direction decreases discontinuously at the stepped portion
from the side that is to be attached to the housing toward the
opposite side.
13. The vent member according to claim 11, wherein the
reinforcement member includes a mesh.
14. The vent member according to claim 13, wherein the mesh is
composed of a resin having substantially the same composition as
that of the resin of which the support body is composed, and fixed
to the stepped portion of the support body by welding.
15. The vent member according to claim 1, wherein the support body
includes a baffle disposed in the through hole to prevent air or
liquid from traveling straight in the through hole.
16. The vent member according to claim 2, further comprising a
reinforcement member whose peripheral portion is fixed to the
support body so as to sandwich the gas permeable membrane between
the support body and itself.
17. The vent member according to claim 16, wherein the peripheral
portion of the reinforcement member extends outward beyond the
opening end face of the support body on the side on which the gas
permeable membrane is disposed, then turns around to a side surface
of the support body and is fixed to the support body.
18. The vent member according to claim 16, wherein the
reinforcement member includes a mesh made of metal or resin.
19. A vent member to be attached to a housing that needs
ventilation, comprising: a support body having a through hole to
serve as a gas passage between the interior and the exterior of the
housing; and a gas permeable membrane fixed to the support body so
as to close the through hole, wherein the support body includes a
base portion to be connected to the housing, an area of the base
portion defined by an outline of a lateral cross-section
perpendicular to a thickness direction of the gas permeable
membrane increases continuously or stepwise from the side on which
the gas permeable membrane is disposed toward the side that is to
be connected to the housing.
20. The vent member according to claim 19, wherein: the lateral
cross-sectional outline of the base portion is approximately
circular and an outer diameter of the base portion increases
continuously, and the through hole is formed so as to extend in the
thickness direction of the gas permeable membrane from an end face
on the large-diameter side to an opening end face on the
small-diameter side of the base portion.
21. The vent member according to claim 20, wherein the height of
the base portion from the end face on the large-diameter side to
the opening end face on the small-diameter side is set to 4 mm or
more.
22. A vent member to be attached to a housing that needs
ventilation, comprising: a support body having an interior space to
serve as a gas passage between the interior and the exterior of the
housing and an opening portion through which the interior space
communicates with the exterior of the housing; and a gas permeable
membrane fixed to the support body so as to close the opening
portion, wherein: assuming that a thickness direction of the gas
permeable membrane is a height direction, one of the end faces of
the support body in the height direction serves as a predetermined
bonding surface that is to be bonded to the housing directly or via
another member, and the height from the predetermined fixing
surface to the end face on the other side on which the opening
portion is formed is set to 4 mm or more.
23. The vent member according to claim 22, wherein: the support
body includes a plurality of the opening portions, and a plurality
of the gas permeable membranes are fixed to the support body so as
to close each of these opening portions.
24. A vent structure, comprising: a housing that needs ventilation;
and a vent member, according to claim 1, attached to an opening
portion of the housing.
25. A vent structure, comprising: a housing that needs ventilation;
and a vent member, according to claim 19, attached to an opening
portion of the housing.
26. A vent structure, comprising: a housing that needs ventilation;
and a vent member, according to claim 22, attached to an opening
portion of the housing.
Description
TECHNICAL FIELD
[0001] The present invention relates to a vent member attached to a
housing that accommodates automobile components, electronic
components or the like. The present invention also relates to a
vent structure using the vent member.
BACKGROUND ART
[0002] Housings that accommodate automobile electrical components
such as lamps, sensors and ECUs (electronic control unit) have a
vent member attached thereto to ensure ventilation between the
interior and the exterior of the housing and to prevent foreign
matter from intruding into the housing. One example of such a vent
member is disclosed in JP 2004-47425A and JP 2003-336874A.
[0003] A vent member disclosed in JP2004-47425A is, for example,
provided with a support body 203 on which a gas permeable membrane
202 is disposed and a cover part 204 attached to the support body
203 so as to cover the gas permeable membrane 202, as shown in FIG.
13. The vent member 201 thus configured is fixed to an opening
portion 207 of a housing 206 via an O-ring 205. Gas is allowed to
permeate through the gas permeable membrane 202 so that ventilation
between the interior and the exterior of the housing 206 is
ensured. The cover part 204 prevents the gas permeable membrane 202
from being damaged by an external force, and deteriorated in gas
permeability due to the deposition of dust.
[0004] The vent member shown in FIG. 13 can be attached to the
opening portion of the housing with ease. Furthermore, the
protrusion from an outer surface of the housing is relatively low.
This seems to be preferable because the vent member occupies no
excess space. However, intensive studies made by the inventor have
found that this is not always the case.
[0005] To be more specific, assume that the gas permeable membrane
of the vent member is close to the outer surface of the housing
when the vent member is attached to the opening portion of the
housing. When water droplets or oil droplets adhere to the outer
surface of the housing in such a case, the water droplets or the
like possibly flow toward a surface of the gas permeable membrane
easily along a side surface the support body to which the gas
permeable membrane is fixed. This phenomenon becomes obvious when
the water droplets or oil droplets remain around a boundary between
the vent member and the housing and the atmospheric pressure inside
the housing rapidly drops below the atmospheric pressure outside
the housing.
DISCLOSURE OF INVENTION
[0006] In view of the foregoing, the present invention has an
object to provide a vent member that can prevent water droplets or
the like from flowing toward the gas permeable membrane even when
the droplets adhere to the outer surface of the housing, and
thereby can maintain gas permeability in a reliable manner. The
present invention has another object to provide a vent structure
using this vent member.
[0007] More specifically, the present invention provides a vent
member to be attached to a housing that needs ventilation. The vent
member includes a support body having a through hole to serve as a
gas passage between the interior and the exterior of the housing
and a gas permeable membrane fixed to the support body so as to
close the through hole. Assuming that a thickness direction of the
gas permeable membrane is a height direction, the support body is
formed so that the through hole extends in the height direction
from one opening end face to the other opening end face, and the
height from the one opening end face to the other opening end face
is set to 4 mm or more.
[0008] Another aspect of the present invention also provides a vent
member to be attached to a housing that needs ventilation. The vent
member includes a support body having a through hole to serve as a
gas passage between the interior and the exterior of the housing,
and a gas permeable membrane fixed to the support body so as to
close the through hole. The support body includes a base portion to
be connected to the housing. An area of the base portion defined by
an outline of a lateral cross-section perpendicular to the
thickness direction of the gas permeable membrane increases
continuously or stepwise from the side on which the gas permeable
membrane is disposed toward the side that is to be connected to the
housing.
[0009] Still another aspect of the present invention provides a
vent member to be attached to a housing that needs ventilation. The
vent member includes a support body having an interior space to
serve as a gas passage between the interior and the exterior of the
housing and an opening portion through which the interior space
communicates with the exterior of the housing, and a gas permeable
membrane fixed to the support body so as to close the opening
portion. Assuming that a thickness direction of the gas permeable
membrane is a height direction, one of the end faces of the support
body in the height direction serves as a predetermined fixing
surface that is to be fixed to the housing directly or via another
member, and the height from the predetermined fixing surface to the
end face on the other side on which the opening portion is formed
is set to 4 mm or more.
[0010] Still another aspect of the present invention provides a
vent structure including a housing that needs ventilation and the
above-mentioned vent member attached to an opening portion of the
housing.
[0011] In the vent member (or the vent structure) of the present
invention described above, the height from the outer surface of the
housing to the opening end face on the opposite side sufficiently
is ensured as 4 mm or more. This makes it possible to prevent water
droplets or the like from flowing onto the gas permeable membrane
even when water droplets or the like remain in areas including a
connection point between the vent member and the housing. In other
words, it is possible to obtain a vent member that can maintain gas
permeability in a reliable manner even when water droplets or the
like adhere to the outer surface of the housing.
[0012] In the vent member (or the vent structure) of another aspect
of the present invention, the support body, to which the gas
permeable membrane is fixed, includes the base portion having a
lateral cross-sectional area increasing continuously or stepwise
toward the housing. According to such a structure, it becomes
difficult for water droplets or the like to remain around the
border between the vent member and the housing. As a result, it is
possible to obtain a vent member that can prevent water droplets or
the like from flowing onto the gas permeable membrane even when the
water droplets or the like adhere to the outer surface of the
housing, and thereby can maintain gas permeability in a reliable
manner.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1A is a perspective view of a vent member of a first
embodiment according to the present invention.
[0014] FIG. 1B is a sectional perspective view of the vent member
of FIG. 1A.
[0015] FIG. 2A is a sectional perspective view of a modification of
the vent member of FIG. 1A.
[0016] FIG. 2B is a sectional perspective view of another
modification of the vent member shown of FIG. 1A.
[0017] FIG. 3A is a perspective view of a vent member of a second
embodiment.
[0018] FIG. 3B is a sectional perspective view of the vent member
of FIG. 3A.
[0019] FIG. 4A is a sectional perspective view of a vent member of
a third embodiment.
[0020] FIG. 4B is a sectional perspective view of a modification of
the vent member of FIG. 4A.
[0021] FIG. 5A is a perspective view of a vent member of a fourth
embodiment.
[0022] FIG. 5B is a sectional perspective view of the vent member
of FIG. 5A.
[0023] FIG. 5C is a sectional perspective view of the modification
of the vent member of FIG. 5A.
[0024] FIG. 5D is a sectional perspective view of another
modification of the vent member shown in FIG. 5A.
[0025] FIG. 6A is a perspective view of a vent member of a fifth
embodiment.
[0026] FIG. 6B is a sectional perspective view of the vent member
of FIG. 6A.
[0027] FIG. 6C is a view explaining operation of the vent member of
FIG. 6A.
[0028] FIG. 6D is a view explaining operation of a conventional
vent member.
[0029] FIG. 7A is a perspective view of a vent member of a sixth
embodiment.
[0030] FIG. 7B is a sectional perspective view of the vent member
of FIG. 7A.
[0031] FIG. 8A is a perspective view of a modification of the vent
member shown in FIG. 7A.
[0032] FIG. 8B is a sectional perspective view of the vent member
of FIG. 8A.
[0033] FIG. 8C is a perspective view of another modification of the
vent member shown in FIG. 7A.
[0034] FIG. 8D is a sectional perspective view of the vent member
of FIG. 8C.
[0035] FIG. 8E is a sectional perspective view of a further
modification of the vent member shown in FIG. 7A.
[0036] FIG. 9A is a perspective view of a vent member of a seventh
embodiment.
[0037] FIG. 9B is a sectional perspective view of the vent member
of FIG. 9A.
[0038] FIG. 10A is a perspective view of a vent member of an eighth
embodiment.
[0039] FIG. 10B is a sectional perspective view of the vent member
of FIG. 10A.
[0040] FIG. 11 is a perspective view of a vent member of a ninth
embodiment.
[0041] FIG. 12 is a general view of a housing on which a vent
member is attached.
[0042] FIG. 13 is a side view of a conventional vent member.
BEST MODE FOR CARRYING OUT THE INVENTION
First Embodiment
[0043] Hereinafter, embodiments of the present invention will be
described with reference to the attached drawings. FIG. 1A is a
perspective view of a vent member of a first embodiment according
to the present invention, and FIG. 1B is a sectional perspective
view thereof. FIG. 12 is a general view of a housing on which the
vent member of FIG. 1A is attached. As shown in FIG. 12, the vent
member 13A shown in FIGS. 1A and 1B constitutes a vent structure
100A for providing ventilation between the interior and the
exterior of a housing 91 when attached to an opening portion 91k of
the housing 91 of, for example, an automobile electrical component.
The housing is not limited to a box-shaped housing as shown in FIG.
12. Any components or articles having an interior space that needs
ventilation can be a housing to which the vent member of the
present invention is to be attached.
[0044] As shown in FIGS. 1A and 1B, the vent member 13A is provided
with a support body 11 having a through hole 11h to serve as a gas
passage between the interior and the exterior of the housing 91 and
a gas permeable membrane 6 disposed on the support body 11 so as to
close one of the openings of the through hole 11h. The support body
11 is of an approximately circular cylindrical shape. The gas
permeable membrane 6 of a circular shape is disposed on a first
opening end face 11p, which is one of the opening end faces of the
circular cylindrical support body 11. A diameter of the gas
permeable membrane 6 is smaller than an outer diameter of the
support body 11 and larger than an inner diameter of the support
body 11 at the first opening end face 11p. The vent member 13A is
fixed to the opening portion 91k of the housing 91 in such a manner
that the through hole 11h of the support body 11, the gas permeable
membrane 6 and the opening portion 91k of the housing 91 are
arranged concentrically. That is, one of the openings of the
through hole 11 formed in the support body 11 is closed by the gas
permeable membrane 6 while the other opening opens toward the
interior of the housing 91. The gas permeable membrane 6 allows a
gas to permeate therethrough and prevents entry of foreign matter,
such as water droplets and dust. The gas permeability of the gas
permeable membrane 6 maintains the pressure inside of the housing
91 equal to the pressure outside of the housing.
[0045] The support body 11 of the vent member 13A includes a cover
16 forming a clearance between the gas permeable membrane 6 and
itself and covering the gas permeable membrane 6 on the side
opposite to the side that is to be attached to the opening portion
91k of the housing 91. In short, of the first opening end face 11p
and a second opening end face 11q, which are the two opening end
faces of the support body 11, the first opening end face 11p
located on the opposite side of the second opening end face 11q is
covered with the cover 16. The clearance is formed between the
first opening end face 11p and the cover 16, and it communicates
with an opening 16h that opens in a direction parallel to an
in-plane of the gas permeable membrane 6. Such a structure protects
the gas permeable membrane 6 from water droplets and dust and
ensures ventilation between the interior and the exterior of the
housing 91 through the gas permeable membrane 6. It should be noted
that in this embodiment, the cover 16 is manufactured as a separate
part from the support body 11 having the through hole 11h. The
cover 16 is combined with the support body 11 after the gas
permeable membrane 6 is fixed on the first opening end face
11p.
[0046] The support body 11 as described above can be manufactured
by popular molding techniques, such as injection molding,
compression molding, and cutting. From the viewpoint of
moldability, a thermoplastic resin is preferably used as a material
for the support body 11. Specifically, thermoplastic resins such as
PBT (polybutylene terephthalate), PA (nylon) and PET (polyethlene
terephthalate), and thermoplastic elastomers such as EPDM (ethylene
propylene rubber) and silicone rubber can be used. The materials
for the support body 11 may include pigments such as carbon black
and titanium white, reinforcement fillers such as glass particles
and glass fibers, and water repellants. The support body 11 repels
liquid (such as water and oil) more easily when applied with a
liquid-repellent treatment on its surface. Other treatments for
providing desired characteristics such as adhesiveness improvement,
electrical insulation, semiconductivity, conductivity may be
applied on the support body 11.
[0047] On the other hand, the gas permeable membrane 6 is not
particularly limited in terms of structure and material as long as
it is a membrane that allows gas permeation while preventing liquid
permeation. This embodiment describes the gas permeable membrane 6
formed by laminating a reinforcing layer on a resin porous
membrane. More specifically, this embodiment describes the gas
permeable membrane 6 with three layers (for example, TEMISH.TM.
available from Nitto Denko Corp.) formed by laminating a resin
porous membrane on top and bottom of a reinforcing layer. With the
reinforcing layer, the gas permeable membrane 6 is allowed to have
a higher strength.
[0048] As a material for the resin porous membrane, a fluororesin
porous body and a polyolefin porous body that can be manufactured
by a known drawing method or extracting method can be used.
Examples of the fluororesin include PTFE (polytetrafluoroethylene),
polychlorotrifluoroethylene,
tetrafluoroethylene-hexafluoropropylene copolymer, and
tetrafluoroethylene-ethylene copolymer. Examples of the monomer of
which the polyolefin is composed include ethylene, propylene and
4-methylpentene-1,1 butene. It is possible to use a polyolefin
obtained by polymerizing these monomers independently or
copolymerizing them. A nanofiber film porous body or the like using
polyacrylonitrile, nylon and polylactate also can be used. In
particular, a PTFE porous body is preferably used because it can
ensure gas permeability even with a small area and prevent foreign
matter from intruding into the housing in a highly effective
manner.
[0049] The liquid-repellent treatment may be applied to the resin
porous membrane that forms the gas permeable membrane 6 in
accordance with the application of the housing. The
liquid-repellent treatment can be carried out by applying the resin
porous membrane with a substance having small surface tension,
drying the substance and then curing the substance. A
liquid-repellent agent used for the liquid-repellent treatment is
not particularly limited as long as it can form a coating having a
surface tension lower than that of the resin porous membrane. For
example, a liquid-repellent agent containing polymers having
perfluoroalkyl groups is suitable. The liquid-repellent agent may
be applied by impregnation, spraying or the like. From the
viewpoint of ensuring sufficient waterproofness, the average pore
diameter of the resin porous membrane is preferably 0.01 .mu.m or
more and not more than 10 .mu.m.
[0050] It is preferable that the material of the reinforcing layer
forming the gas permeable membrane 6 excels more in gas
permeability than the resin porous membrane. Specifically, a
fabric, a nonwoven fabric, a mesh, a net, a sponge, a form, a
porous body (Sunmap available from Nitto Denko Corp., for example)
or the like can be used. These are made of resin or metal. Examples
of the methods for bonding the resin porous membrane to the
reinforcing layer include adhesive lamination, heat lamination,
heat welding, laser welding, ultrasonic welding, and the use of an
adhesive agent.
[0051] The thickness of the gas permeable membrane 6 is set in the
range of, for example, 1 .mu.m to 5 mm, taking into account its
strength and the ease of fixing to the support body 11. The gas
permeability of the gas permeable membrane 6 is preferably in a
rage of 0.1 to 300 sec/100 cm.sup.3 in terms of Gurley value.
Although the gas permeable membrane 6 is fixed to the support body
11 by heat welding in this embodiment, the gas permeable membrane 6
may be fixed to the support body 11 by other methods such as
ultrasonic welding and the use of an adhesive agent.
[0052] Descriptions made herein regarding the support body and the
gas permeable membrane apply to other embodiments to be described
later.
[0053] A thickness direction of the gas permeable membrane 6 is
assumed as a height direction in the descriptions hereinafter
including other embodiments. It is also assumed that the surface of
the gas permeable membrane 6 facing to the side of the housing 91
is an under surface while the surface on the opposite side is an
upper surface.
[0054] As shown in FIGS. 1A and 1B, an outer surface 91p of the
housing 91 surrounding the vent member 13A is a flat surface
approximately parallel to a principal surface of the gas permeable
membrane 6 in this embodiment. As shown in FIG. 1B, the second
opening end face 11q on the opposite side of the first opening end
face 11p to which the gas 6 is fixed is a bonding surface that is
directly bonded to the opening portion 91k of the housing 91. The
through hole 11h is formed so as to extend almost linearly in the
height direction from the second opening end face 11q to the first
opening end face 11p.
[0055] In the support body 11, a height H.sub.1 from the second
opening end face 11q to the gas permeable membrane 6, in other
words, a height H.sub.i from the outer surface 91p of the housing
91 surrounding the vent member 13A to the gas permeable membrane 6,
is set to 4 mm or more. When thus configured, it is possible to
prevent the water droplets or the like adhering to the outer
surface 91p of the housing 91 from flowing onto the gas permeable
membrane 6 in a highly effective manner. The height H.sub.1 of 4 mm
or more makes it difficult for the water droplets or the like
adhering to the housing 91 to reach the gas permeable membrane 6
under normal conditions. The height H.sub.1 is set preferably to 6
mm or more, further preferably to 10 mm or more, in order to
prevent the water droplets or the like from contacting the gas
permeable membrane 6 in a more reliable manner. It is desirable,
however, that the height H.sub.1 is 30 mm or less in order to avoid
an excessive protrusion of the vent member 13A from the outer
surface 91p of the housing 91. These dimensions apply to other
embodiments to be described later.
[0056] A method such as heat welding, ultrasonic welding, laser
welding, the use of an adhesive tape, the use of an adhesive agent
can be adopted for fixing the vent member 13A to the opening
portion 91k of the housing 91. In the vent member 13A shown in
FIGS. 1A and 1B, the height H.sub.1 of the support body 11 from the
outer surface 91p of the housing 91 to the under surface of the gas
permeable membrane 6 is set to be smaller than the outer diameter
of the support body 11 in a cross section perpendicular to the
height direction. This makes it possible to obtain a sufficient
stability when the vent member 13A is fixed to the opening portion
91k of the housing 91, and thereby reduce the possibility that the
vent member 13A falls off the housing 91 when an impact is applied
thereto by foreign matter or the like.
[0057] Ribs 14, 14 protruding outward in a radial direction may be
provided at plural points in a circumferential direction on the
side of the second opening end face 11q, like a vent member 13B
shown in FIG. 2A. The ribs 14, 14 are bonded to the outer surface
91p of the housing 91. According to a vent structure 100B in which
the vent member 13B is attached to the opening portion 91k of the
housing 91, the bonding strength between the vent member 13B and
the housing 91 can be increased with ease. The ribs 14, 14
configured in this manner can be adopted in any embodiments to be
described later.
[0058] Incidentally, the vent member of the present invention is,
in some cases, available for so-called insert molding. In the
insert molding, the vent member is inserted to a mold for molding
the housing so as to be integrated with the resin of which the
housing will be composed. According to such an insert molding
method, good productivity is achieved because it can omit the step
of attaching the vent member to the housing. However, there may be
a possibility that a rate of occurrence of defective products rises
in exchange for the reduced number of production steps. This is
because when the insert molding is being carried out, a high
atmospheric pressure is applied to the gas permeable membrane of
the vent member, causing the gas permeable membrane to fall off the
support body or to be broken in some cases. In order to deal with
this problem, the improvement below is effective.
[0059] That is, like a vent member 13C included in a vent structure
100C shown in FIG. 2B, a gas permeable membrane 8 can be used that
includes a main membrane body 6 formed of the resin porous membrane
and a gas-permeable reinforcement member 7 attached to the main
membrane body 6 so as to cover at least one of the principal
surfaces of the main membrane body 6. The main membrane body 6 is
reinforced by the reinforcement member 7. When configured in this
manner, it is possible to prevent or suppress occurrence of
failures, such as separation and breakage of the main membrane body
6 during the housing 91 is being molded. The main membrane body 6
is exactly the gas permeable membrane shown in FIGS. 1A and 1B, as
can be understood from the fact that the same reference numeral is
given to each of them.
[0060] The reinforcement member 7 is required to have
characteristics that can ensure the gas permeability of the main
membrane body 6 and excel more at preventing separation and
breakage than the main membrane body 6. Hence, it is preferable
that the reinforcement member 7 includes a mesh made of metal or
resin. It is more preferable that the reinforcement member 7 is
formed of a mesh. It is preferable that the main membrane body 6
and the reinforcement member 7 are bonded by heat welding or the
use of an adhesive agent to be integrated together. It is also
preferable that the reinforcement member 7 is composed of a resin
having substantially the same composition as that of the resin of
which the support body is composed. This allows the support body 11
and the reinforcement member 7 to be bonded together more tightly
by a welding method, such as heat welding, ultrasonic welding and
laser welding. The metal or resin mesh may be formed of woven metal
wires or woven resin wires, a sheet perforated with many holes like
a known punching metal, and a molded body manufactured by a known
molding method using a mold, and further, a grid-like material
having a high rigidity. In the example of FIG. 2B, the
reinforcement member 7 is bonded only to one side of the main
membrane body 6, but it may be disposed on both sides of the main
membrane body 6. The term "substantially the same composition"
referred to herein is not intended to exclude the case where an
inevitable impurity is contained, and the case where a slight
difference exists that has no significant effect on the
characteristics.
[0061] In the vent member described in this and other embodiments,
the support body may be dividable into an upper portion and a lower
portion in the area other than the cover. Furthermore, a vent
member provided with a support body having no cover and the gas
permeable membrane exposed upward may be adopted.
Second Embodiment
[0062] FIG. 3A is a perspective view of a vent member of a second
embodiment, and FIG. 3B is a sectional perspective view thereof. A
vent structure 102 for performing ventilation between the interior
and the exterior of the housing 91 is constituted by attaching a
vent member 23 shown in FIGS. 3A and 3B to the opening portion 91k
of the housing 91.
[0063] The vent member 23 is provided with a support body 21 having
a through hole 21h and 21i to serve as a gas passage between the
interior and exterior of the housing 91 and the gas permeable
membrane 6 fixed to the support body 21 so as to close the through
hole 21h and 21i. A second opening end face 21q serves as a bonding
surface that is directly bonded to the housing 91. The support body
21 includes a cover 26 covering the gas permeable membrane 6. A
clearance between the gas permeable membrane 6 and the cover 26
communicates with an opening 26h that opens in a direction parallel
to the in-plane of the gas permeable membrane 6. The vent member 23
shares these points with the vent member 13 of the first
embodiment.
[0064] On the other hand, a first opening end face 21p located on
the farther side from the housing 91 serves as an end face to which
the cover 26 is fixed. The gas permeable membrane 6 is not disposed
on the first opening end face 21p. In this embodiment, the gas
permeable membrane 6 is disposed in the through hole 21h and 21i.
The through hole 21h and 21i is formed of a first portion 21h that
is outside of the housing 91 and a second portion 21i that is
inside of the housing 91, and divided by the gas permeable membrane
6. When the gas permeable membrane 6 is disposed in the through
hole 21h and 21i in such a manner, a height H.sub.3 of the support
body 21 from the second opening end face 21q (an end face aligned
with the outer surface 91p of the housing 91) to the first opening
end face 21p on the opposite side may be set to 4 mm or more. When
configured in this manner, it is possible to prevent highly
effectively the water droplets or the like adhering to the outer
surface 91p of the housing 91 from flowing over the support body 21
and intruding into the through hole 21h.
[0065] More preferably, a height H.sub.2 of the support body 21
from the second opening end face 21q to the under surface of the
gas permeable membrane 6 is 4 mm or more. When configured in this
manner, it is possible to obtain a sufficient length for the
through hole 21i which is inside of the housing 91. The through
hole 21i with an adequate length is advantageous in that it can
prevent water droplets from immediately adhering to the gas
permeable membrane 6 even when moisture condensation occurs in the
housing 91 because the water droplets slowly flows inside of the
through hole 21i. This is also preferable because the height
H.sub.3 from the outer surface 91p of the housing 91 to the first
opening end face 21p naturally becomes 4 mm or more when the height
H.sub.2 from the outer surface 91p of the housing 91 to the gas
permeable membrane 6 is set to 4 mm or more.
[0066] The support body 21 includes a stepped portion 211 formed
along an entire circumference inside the through hole 21h and 21i.
A cross-sectional area of the through hole 21h and 21i with respect
to a lateral direction perpendicular to the height direction
changes discontinuously at the stepped portion. In other words, the
stepped portion 211 includes the boundary between the first portion
21h and the second portion 21i of the through hole 21h and 21i. The
gas permeable membrane 6 is disposed on this stepped portion 211.
According to this structure, the gas permeable membrane 6 can be
disposed in the through hole 21h and 21i easily and reliably. By
disposing the gas permeable membrane 6 in the through hole 21h and
21i, it is possible to protect the gas permeable membrane 6 from
water droplets and dust that come flying from the lateral
direction. In this embodiment, the diameter of the through hole
21h, which is outside of the housing 91, is set to be larger than
the diameter of the gas permeable membrane 6. The gas permeable
membrane 6 is inserted from the through hole 21h to be fixed to the
stepped portion 211. When configured in this manner, the gas
permeable membrane 6 can be fixed to the stepped portion 211 with
ease.
[0067] A reinforced gas permeable membrane 8 (see FIG. 2B) may be
used instead of the gas permeable membrane 6. In this case, the gas
permeable membrane 8 is fixed to the support body 21 so that the
reinforcement member 7 or the main membrane body 6 is in contact
with a seating face of the stepped portion 211.
Third Embodiment
[0068] A vent member 43A of a third embodiment shown in FIG. 4A is
a modification of the vent member 23 of the second embodiment. A
vent structure 106A is constituted by attaching the vent member 43A
to the opening portion 91k of the housing 91. This embodiment is
common with the embodiments above in that a through hole 41h and
41i is divided into an upper portion and a lower portion by the gas
permeable membrane 6, a support body 41 includes a cover 46, and a
height H.sub.7 from the outer surface 91p of the housing 91 to a
first opening end face 41p is set to 4 mm or more. A difference is
that the gas permeable membrane 6 is integrated with the support
body 41 by insert molding.
[0069] As shown in FIG. 4A, the gas permeable membrane 6 is fixed
to the support body 41 in the through hole 41h and 41i by
integrating a peripheral portion 6k with the resin of which the
support body 41 is composed. In other words, the peripheral portion
6k of the gas permeable membrane 6 is embedded into the support
body 41. When configured in this manner, the gas permeable membrane
6 can be fixed to the support body 41 more tightly. Should the vent
member 43A be exposed to a strong water stream, the gas permeable
membrane 6 will not fall off the support body 41. It is preferable
also in this embodiment that the support body 41 of the vent member
43A has a height H.sub.6 of 4 mm or more from the outer surface 91p
(aligned with a second opening end face 41q) of the housing 91 to
the gas permeable membrane 6.
[0070] In the vent member 43A of this embodiment, the outer
diameter of an opening portion 41L on the side that is bonded to
the housing 91 is larger than the outer diameter of the opening
portion on the opposite side. According to the support body 41 with
the opening portion 41L, the area of the bonding surface 41q is
increased, and thereby the bonding strength between the vent member
43A and the housing 91 is enhanced. It goes without saying that the
opening portion 41L can be adopted to an vent member of other
embodiments.
[0071] Like a vent member 43B included in a vent structure 106B
shown in FIG. 4B, it is also possible to use the gas permeable
membrane 8 including the main membrane body 6 and the reinforcement
member 7. In this case, the peripheral portion of the main membrane
body 6 and that of the reinforcement member 7 are both embedded
into the support body 41. The gas permeable membrane 8 can be fixed
to the support body 41 more tightly with the combination of the
reinforcing effect of the reinforcement member 7 and the effect of
being embedded into the support body 41.
Fourth Embodiment
[0072] FIG. 5A is a perspective view of a vent member of a fourth
embodiment, and FIG. 5B is a sectional perspective view thereof. A
vent member 53A shown in FIG. 5A and FIG. 5B is a modification of
the second embodiment. The gas permeable membrane 6 is disposed in
a through hole 51h and 51i of a support body 51, the support body
51 includes a cover 51a, and a height H.sub.8 from the outer
surface 91p of the housing 91 to a first opening end face 51p is
set to 4 mm or more. These points are common with the vent member
23 and the vent structure 102 shown in FIGS. 3A and 3B. It is also
common in that a second opening end face 51q of the support body 51
serves as a bonding surface to the housing 91, and a vent structure
108A is constituted by attaching the vent member 53A to the opening
portion 91k of the housing 91.
[0073] As shown in FIG. 5B, the support body 51 includes a stepped
portion 511 formed along an entire circumference inside the through
hole 51h and 51i. A cross-sectional area of the through hole 51h
and 51i with respect to a lateral direction perpendicular to the
height direction changes discontinuously at the stepped portion
511. In other words, the stepped portion 511 includes the boundary
between a first portion 51h and a second portion 51i of the through
hole 51h and 51i. The gas permeable membrane 6 is disposed on this
stepped portion 511. It should be noted that in the vent member
53A, of the through hole 51h and 51i of the support body 51, the
through hole 51h exposed to outside of the housing 91 has a smaller
diameter than the through hole 51i that is inside of the housing
91. The gas permeable membrane 6 is inserted into the through hole
51i from the side of the second opening end face 51q connected to
the opening portion 91k of the housing 91, and then disposed on the
stepped portion 511.
[0074] According to the vent member 53A, a cross-sectional area of
the through hole 51h and 51i with respect to a lateral direction
discontinuously becomes smaller at the stepped portion 511 from the
side attached to the housing 91 toward the opposite side.
Therefore, the gas permeable membrane 6 is pressed onto a seating
face of the stepped portion 511 when an air pressure is applied in
a direction from the housing 91 side to the opposite side. Hence,
it is possible to reduce a rate of occurrence of separation and
breakage of the gas permeable membrane 6 during the housing 91 with
the vent member 53A is being manufactured by insert molding.
[0075] More preferably, the gas permeable membrane 8 reinforced
with the reinforcement member 7 is used like a vent member 53B
included in a vent structure 108B shown in FIG. 5C. In this case,
the gas permeable membrane 8 is fixed to the support body 51 so
that the reinforcement member 7 is in contact with the seating face
of the stepped portion 511. According to the vent member 53B, the
main membrane body 6 is pressed onto the reinforcement member 7
when an air pressure is applied in a direction from the side of the
housing 91 to the opposite side. The reinforcement member 7
preferably includes a mesh made of metal or resin, or a porous body
(Sunmap available from NITTO DENKO Corp., for example) and has a
rigidity higher than that of the main membrane body 6. The
reinforcement member 7 thus configured has low possibilities of
breakage and separation from the support body 51 due to an air
pressure applied during the insert molding, and thereby firmly
supports the main membrane body 6 at all times. As described above,
it is preferable that the reinforcement member 7 is composed of a
resin having substantially the same composition as that of the
resin of which the support body 51 is composed.
[0076] It is preferable in this embodiment as well that the support
body 51 of the vent member 53A and 53B has a height H.sub.9 of 4 mm
or more from the outer surface 91p of the housing 91 to the gas
permeable membrane 6.
[0077] Furthermore, in this embodiment, the cover 51a of the
support body 51 is integrally manufactured by injection molding
with a body part in which the through hole 51h and 51i is formed.
It should be noted, however, that there is no change in that a
clearance between the gas permeable membrane 6 and the cover 51a
communicates with an opening 52 that opens in a direction parallel
to the in-plane of the gas permeable membrane 6.
[0078] A vent member 53D shown in FIG. 5D also is suitable. A
support body 51D of the vent member 53D includes baffles 51e and
51f that are disposed in the way of a gas passage running from the
gas permeable membrane 6 to the housing 91 and prevent gas or
liquid from traveling straight with respect to the height direction
in the through hole 51i. By disposing these baffles 51e and 51f in
the through hole 51i, it is possible to prevent water droplets from
flowing directly to the gas permeable membrane 6 even when moisture
condensation occurs in the housing 91. When configured in this
manner, it is possible to ensure the gas permeability of the gas
permeable membrane 6 at all times and eliminate the moisture
condensation in the housing 91 smoothly. These baffles 51e and 51f
can be adopted in any other embodiment.
Fifth Embodiment
[0079] A support body 61 of a vent member 63 shown in FIGS. 6A and
6B includes a base portion 611 to be connected to the housing 91.
An area of the base portion 611 defined by an outline of a lateral
cross-section perpendicular to the thickness direction of the gas
permeable membrane 6 increases continuously or stepwise from the
side on which the gas permeable membrane 6 is disposed toward the
side that is to be connected to the housing 91. The base portion
611 of the support body 61 is fixed to the opening portion 91k of
the housing 91. The upper portion (opposite side to the housing)
adjacent to the base portion 611 is a fixed-diameter portion 610
having a fixed outer diameter. A cover 61a covering the gas
permeable membrane 6 is included in the fixed-diameter portion 610.
A clearance between the gas permeable membrane 6 and the cover 61a
communicates with an opening 62 that opens in a direction parallel
to the in-plane of the gas permeable membrane 6. A vent structure
110 is constituted by attaching the vent member 63 to the opening
portion 91k of the housing 91. The base portion 611 of the support
body 61 prevents the water droplets or the like adhering to the
outer surface 91p of the housing 91 from accumulating around the
vent member 63.
[0080] FIG. 6C is a view explaining operation of a vent member of
this embodiment and FIG. 6D is that of a conventional vent member.
First, as shown in FIG. 6C, according to the vent member 63 of this
embodiment having a sloping side surface so as to be wider toward
the housing 91, a water droplet W has to increase its surface area
in order to accumulate between the vent member 63 and the outer
surface 91p of the housing 91, and thus becomes unstable. Thereby
the water droplet W smoothly is removed from the area around the
vent member 63. On the other hand, as shown in FIG. 6D, a
conventional vent member 201 has a side surface rising
perpendicularly. This allows the water droplet W to have a smaller
surface area and become stable when accumulating between the vent
member 201 and the outer surface 91p of the housing 91. As a
result, the water droplet W tends to stay around the vent member
201 and flow onto the gas permeable membrane 6 more easily.
Especially, this becomes obvious with the conventional vent member
201 (FIG. 13) whose height to the gas permeable membrane is
insufficient.
[0081] As shown in FIGS. 6A and 6B, in the vent member 63, the
above-mentioned cross-sectional outline of the base portion is
approximately circular, and a diameter of the base portion
increases continuously. Through hole 61h and 61i is formed so as to
extend in the height direction from an end face 61q on the
larger-diameter side to an opening end face 61p on the
smaller-diameter side of the base portion 611. The gas permeable
membrane 6 is disposed in the through hole 61h and 61i. The base
portion 611 having the circular cross-section even more effectively
prevents water droplets or the like from accumulating around the
vent member 63.
[0082] Furthermore, it is preferable that a height H.sub.10 from
the end face 61q (a second opening end face 61q aligned with the
outer surface 91p of the housing 91) on the large-diameter side to
the opening end face 61p (a first opening end face 61p) on the
small-diameter side is set to 4 mm or more. More preferably, a
height H.sub.11 from the end face 61q on the larger-diameter side
of the base portion 611 to the gas permeable membrane 6 is set to 4
mm or more as in the embodiments above. When configured in this
manner, it is possible to prevent the water droplets or the like
adhering to the outer surface 91p of the housing 91 from flowing
toward the gas permeable membrane 6, and thereby the vent structure
110 with excellent waterproofness can be obtained.
[0083] In the embodiment of FIGS. 6A and 6B, the base portion 611
has an outer diameter increasing continuously toward the side of
the housing 91. However, it is possible to provide a base portion
whose outer diameter increases stepwise. The structure with a
sloping side surface may be applied to other embodiments. For
example, the vent member can be of a very simple structure by
removing the cover 61a and disposing the gas permeable membrane 6
on the opening end face 61p. The reinforced gas permeable membrane
8 (see FIG. 5C) can be suitably adopted instead of the gas
permeable membrane 6.
Sixth Embodiment
[0084] A vent member 73 shown in FIGS. 7A and 7B is provided with a
box-shaped support body 71 and the gas permeable membrane 6 fixed
to the support body 71 so as to close an opening portion 71k of the
box-shaped support body 71. The box-shaped support body 71 has an
interior space SH to serve as a gas passage between the interior
and the exterior of the housing 91 and the opening portion 71k
through which the interior space SH communicates with the exterior
of the support body 71. Assuming that a thickness direction of the
gas permeable membrane 6 is a height direction, one end face 71q of
the support body 71 in the height direction serves as a bonding
surface 71q directly bonded to the housing 91. The vent member 73
is fixed directly to the housing 91 so that the opening portion 91k
of the housing 91 is exposed to the interior space SH of the
support body 71. In the support body 71, a height H.sub.12 from the
bonding surface 71q to an end face 71p in which the opening portion
71k is formed is set to 4 mm or more. When configured in this
manner, it is possible to prevent the water droplets or the like
adhering to the outer surface 91p of the housing 91 from flowing
onto the gas permeable membrane 6.
[0085] In the vent member 73 of this embodiment, the opening
portion 91k of the housing 91 and the gas permeable membrane 6 are
arranged in a staggered positional relationship in an in-plane
direction (lateral direction) perpendicular to the height
direction. To be more specific, a central axis O.sub.1 of the
circular gas permeable membrane 6 and a central axis O.sub.2 of the
opening portion 91k (also circular) of the housing 91 are not
aligned. In a projection view in the height direction, the opening
portion 71k of the support body 71 and the opening portion 91k of
the housing 91 are arranged so as to avoid overlapping each other
in the in-plane. According to such a positional relationship, the
interior space SH of the vent member 73 increases in the in-plane
direction, making even more difficult for the water droplets or the
like to reach the gas permeable membrane 6.
[0086] As shown in FIGS. 8A and 8B, it is possible to adopt a vent
member 78 that includes a support body 76 having plural openings
76k, 76k and plural gas permeable membranes 6, 6 fixed to the
support body 76 so as to close each of these openings 76k, 76k. A
vent structure 115 is constituted by fixing the vent member 78 to
the housing 91 in such an arrangement that the opening portion 91k
of the housing 91 is located almost in the middle between the
opening portions 76k, 76k that are adjacent to each other on the
support body 76. The central axes O.sub.1 and O.sub.3 of the gas
permeable membranes 6, 6 are not aligned with the central axis
O.sub.2 of the opening portion 91k of the housing 91. According to
the vent structure 115, the ventilation level inside the housing 91
is extremely high.
[0087] An end face 76q, which is on the opposite side of an end
face 76p on which the gas permeable membranes 6 and 6 are disposed,
serves as a bonding surface that is in contact with the outer
surface 91p of the housing 91. The height H.sub.12 from the outer
surface 91p of the housing 91 to the end face 76p in which opening
portions 76k, 76k are formed is 4 mm or more as in the embodiments
described so far. This prevents the water droplets or the like
adhering to the outer surface 91p of the housing 91 from flowing
onto the gas permeable membranes 6, 6.
[0088] The gas permeable membranes 6, 6 closing the opening
portions 76k, 76k may be disposed from the side of the interior
space SH of the box-shaped support body 76 like a vent member 78A
and a vent structure 115A shown in FIGS. 8C and 8D. In a vent
structure 115B shown in FIG. 8E, a vent member 78B with a cover 76a
covering the gas permeable membranes 6, 6 is adopted. The vent
member 78B is provided with the cover 76a forming a clearance
between itself and the gas permeable membranes 6, 6 while covering
the gas permeable membranes 6, 6 on the side opposite to the side
that is attached to the housing 91. The cover 76a can protect the
gas permeable membranes 6, 6 from a strong water stream and dust in
a reliable manner. Since the cover 76a opens in a direction
parallel to the in-plane of the gas permeable membrane 6, there is
no fear that the gas permeability of the gas permeable membrane 6
will be decreased.
Seventh Embodiment
[0089] A vent structure 117 shown in FIGS. 9A and 9B adopts a vent
member 83 including upper faces of different heights. To be more
specific, a support body 81 of the vent member 83 is formed of a
tubular portion 81a on which the gas permeable membrane 6 is
disposed and a box-shaped portion 81b having the interior space SH
that communicates with the tubular portion 81a. The tubular portion
81a has a through hole 81h to serve as a gas passage. The gas
permeable membrane 6 is disposed on an opening end face 81p of the
tubular portion 81a, and closes the through hole 81h from the side
opposite to the side adjacent to the box-shaped portion 81b. A
height H.sub.13 from the outer surface 91p of the housing 91 to the
gas permeable membrane is 4 mm or more as in the embodiments above.
Furthermore, the tubular portion 81a and the box-shaped portion 81b
jointly form a stepped shape. This configuration makes it difficult
for the water drops or the like adhering to the outer surface 91p
of the housing 91 to flow toward the gas permeable membrane 6. When
the space allowed for placing the vent structure 117 is partially
insufficient, the vent member 83 having different heights at
different points like this embodiment may be adopted. In short, the
tubular portion 81a with the gas permeable membrane 6 is located in
an area where a sufficient space can be taken while the box-shaped
portion 81b with a reduced height is located in an area where there
is no sufficient space.
Eighth Embodiment
[0090] Major features of a vent member 153 shown in FIGS. 10A and
10B are common with those of the vent member 53B shown in FIG. 5C,
although the shape is different. That is, a support body 151 of the
vent member 153 is provided with a through hole 151h to serve as a
gas passage having a noncircular (rectangular in this embodiment)
cross section. The support body 151 includes a stepped portion 512
on which a gas permeable membrane 8 is disposed and a cover 151a
that prevents the through hole 151h from directly being exposed
upward. The through hole 151h communicates with an opening 152 that
opens in a lateral direction. The stepped portion 512 of the
support body 151 is provided with a countersink 512g for fitting
the gas permeable membrane 8 (specifically the portion of the
reinforcement member 7), and thereby the gas permeable membrane 8
easily can be located with respect to the support body 151.
According to the vent member 153 of this embodiment, material waste
can be minimized by adopting the rectangular gas permeable membrane
8.
[0091] The support body 151 of the vent member 153 includes a rib
154 for ultrasonic welding. Friction generated by a ultrasonic wave
is concentrated on the rib 154 and melt it quickly for bonding the
vent member 153 to the housing. Thereby the time needed for the
bonding process can be shortened. The rib 154 may be provided to
the support bodies of other embodiments.
Ninth Embodiment
[0092] A problem such as separation and breakage of the gas
permeable membrane during the insert molding also can be prevented
by a vent member 163 included in a vent structure 160 shown in FIG.
11. The vent member 163 is provided with the gas permeable membrane
6, a circular cylindrical support body 161 on one of whose opening
end faces the gas permeable membrane 6 is disposed, and a
reinforcement member 9 with a peripheral portion 9s fixed to the
support body 161 so as to sandwich the gas permeable membrane 6
between the support body 161 and itself. The peripheral portion 9s
of the reinforcement member 9 extends outward beyond the opening
end face of the support body 161 on the side on which the gas
permeable membrane 6 is disposed. The peripheral portion 9s turns
around to a side surface of the support body 161 and is fixed to
the support body 161. When configured in this manner, it is
possible to prevent the gas permeable membrane 6 from breaking and
separating from the support body 161 even if a high air pressure is
applied thereto from the housing 91 side.
[0093] Like the reinforcement member 7 described in the embodiments
above, the reinforcement member 9 preferably includes a porous body
or a mesh, and more preferably, the reinforcement member 9 consists
of a mesh made of metal or resin. Furthermore, it is preferable
that the reinforcement member 9 has flexibility so that the
peripheral portion 9s can fit along the side surface of the support
body 161 with ease, and accordingly the reinforcement member 9 can
be fixed to the support body 161 in a reliable manner. For example,
a mesh made of resin is suitable as the reinforcement member 9
because it has excellent flexibility and strength. The
reinforcement member 9 may or may not be bonded directly to the gas
permeable membrane 6. In other words, the reinforcement member 9
simply may be placed on the gas permeable membrane 6. The method of
fixing the peripheral portion 9s of the reinforcement member 9 to
the support body 161 is not particularly limited. A method such as
welding, the use of an adhesive agent, an adhesive tape or the like
can be adopted.
[0094] It should be noted that some of the embodiments described
above may be used in combination without departing from the
technical scope of the present invention.
INDUSTRIAL APPLICABILITY
[0095] A vent member of the present invention is suitable for
housings of autoparts, such as lamps, motors, sensors, switches,
ECUs, and gearboxes. Especially, the vent member of the present
invention exhibits remarkable effect when it is attached to a
housing that easily causes moisture condensation inside, directly
is exposed to a rainstorm, or receives water streams during car
washing. The vent member of the present invention also can be
suitably attached to housings of electric appliances, such as
mobile communication devices, cameras, electric shavers, and
electric toothbrushes, besides autoparts.
* * * * *