U.S. patent application number 13/637877 was filed with the patent office on 2013-01-17 for diaphragm.
This patent application is currently assigned to ADVICS CO., LTD.. The applicant listed for this patent is Koji Aoba, Kazuma Shigeta, Shuji Takeshita. Invention is credited to Koji Aoba, Kazuma Shigeta, Shuji Takeshita.
Application Number | 20130014639 13/637877 |
Document ID | / |
Family ID | 44712133 |
Filed Date | 2013-01-17 |
United States Patent
Application |
20130014639 |
Kind Code |
A1 |
Takeshita; Shuji ; et
al. |
January 17, 2013 |
DIAPHRAGM
Abstract
Disclosed is a diaphragm having a flexible film portion and an
outer peripheral flange portion integrally provided on the
peripheral edge of the film portion, said outer peripheral flange
portion being provided between and held by a first housing and a
second housing, wherein the film portion is prevented from rising
upward when the diaphragm is attached to the housings. The outer
peripheral flange portion has a first pressed surface which is one
surface of the diaphragm in the thickness direction and which is in
close contact with the first housing, and a three-dimensional shape
composed of a projected portion or a recessed portion, on the first
pressed surface. When the outer peripheral flange portion is
attached to the first housing and the second housing while being
compressed and deformed therebetween, the three-dimensional shape
defines voids in the thickness direction between the outer
peripheral flange portion and the first housing.
Inventors: |
Takeshita; Shuji; (Aso,
JP) ; Shigeta; Kazuma; (Kariya, JP) ; Aoba;
Koji; (Kariya, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Takeshita; Shuji
Shigeta; Kazuma
Aoba; Koji |
Aso
Kariya
Kariya |
|
JP
JP
JP |
|
|
Assignee: |
ADVICS CO., LTD.
Kariya-city, Aichi
JP
NOK CORPORATION
Tokyo
JP
|
Family ID: |
44712133 |
Appl. No.: |
13/637877 |
Filed: |
March 24, 2011 |
PCT Filed: |
March 24, 2011 |
PCT NO: |
PCT/JP2011/057082 |
371 Date: |
September 27, 2012 |
Current U.S.
Class: |
92/96 |
Current CPC
Class: |
F15B 2201/205 20130101;
F16J 3/02 20130101; F15B 1/125 20130101; F15B 2201/3151 20130101;
F15B 2201/3156 20130101; F15B 2201/61 20130101 |
Class at
Publication: |
92/96 |
International
Class: |
F01B 19/02 20060101
F01B019/02 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 29, 2010 |
JP |
2010-074546 |
Claims
1-5. (canceled)
6. A diaphragm comprising a flexible film portion and an outer
peripheral flange portion integrally provided on a peripheral edge
of the film portion, wherein at least a portion of one surface in
the thickness direction of the film portion and at least a portion
of one end surface in the thickness direction of the outer
peripheral flange portion are arranged on the same plane to be a
flat surface, wherein another end surface in the thickness
direction of the outer peripheral flange portion protrudes more in
the thickness direction than another surface in the thickness
direction of the film portion, wherein, when the diaphragm is
attached between a pair of a first housing and a second housing,
the outer peripheral flange portion becomes to be a state
compressed between the first housing and the second housing, and
the film portion becomes to be a state in which one surface of the
film portion in the thickness direction is in contact with the
first housing over the approximately whole surface of the one
surface of the film portion, wherein the one end surface in the
thickness direction of the outer peripheral flange portion includes
a first pressed surface contacting the first housing, and a three
dimensional shape comprising a projected portion or a recessed
portion is provided on the first pressed surface, wherein, when the
outer peripheral flange portion is compressed in the thickness
direction between a pair of the first housing and the second
housing, the three-dimensional shape defines voids in the thickness
direction between the outer peripheral flange portion and the first
housing, wherein the voids in the thickness direction absorbs
compression and deformation of the outer peripheral flange portion,
so that the influence of the compression and deformation hardly
reaches to the film portion, and rising upward of the film portion
from the first housing is prevented.
7. The diaphragm according to claim 6, wherein the
three-dimensional shape is an annular projection provided on a
center portion in the diameter direction of the first pressed
surface, wherein, when the outer peripheral flange portion is
attached to the first housing and the second housing while being
compressed and deformed therebetween, the three-dimensional shape
defines voids in the diameter direction on the more outer side than
the annular projection on the first pressed surface.
8. The diaphragm according to claim 6, wherein, when the outer
peripheral flange portion is attached between the first housing and
the second housing, the outer peripheral flange portion is set to
have an outer diameter size enabling to define voids in the
diameter direction between the outer peripheral surface of the
outer peripheral flange portion and at least one of the first
housing and the second housing, in the diameter direction of the
diaphragm.
9. The diaphragm according to claim 6, wherein the outer peripheral
flange portion includes a second pressed surface and a
three-dimensional shape, wherein the second pressed surface is
another surface in the thickness direction of the diaphragm and is
pressed by the second housing, wherein the three-dimensional shape
includes a projected portion or a recessed portion on the second
pressed surface.
10. A diaphragm supporting structure sandwiching a diaphragm by a
first housing and a second housing, wherein the diaphragm
supporting structure includes the diaphragm according to claim 6 as
the diaphragm.
11. The diaphragm according to claim 7, wherein, when the outer
peripheral flange portion is attached between the first housing and
the second housing, the outer peripheral flange portion is set to
have an outer diameter size enabling to define voids in the
diameter direction between the outer peripheral surface of the
outer peripheral flange portion and at least one of the first
housing and the second housing, in the diameter direction of the
diaphragm.
12. The diaphragm according to claim 8, wherein the outer
peripheral flange portion includes a second pressed surface and a
three-dimensional shape, wherein the second pressed surface is
another surface in the thickness direction of the diaphragm and is
pressed by the second housing, wherein the three-dimensional shape
includes a projected portion or a recessed portion on the second
pressed surface.
13. A diaphragm supporting structure sandwiching a diaphragm by a
first housing and a second housing, wherein the diaphragm
supporting structure includes the diaphragm according to claim 9 as
the diaphragm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage Application of
International Application No. PCT/JP2011/057082, filed on Mar. 24,
2011 and published in Japanese as WO 2011/122424-A1 on Oct. 6,
2011. This application claims the benefit of Japanese Application
No. 2010-074546, filed on Mar. 29, 2010. The entire disclosures of
the above applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a diaphragm, and more
particularly, the diaphragm suitably used for an accumulator of a
fluid pressure control apparatus for a vehicle, or the like.
[0004] 2. Description of the Conventional Art
[0005] From conventional, as illustrated in FIG. 5, a diaphragm 1
made of a rubber-like elastic body, and including a flexible film
portion 2 and an outer peripheral flange portion 3 integrally
provided on the peripheral edge of the film portion 2, has been
known. The diaphragm 1 is used in, for example, the accumulator of
the fluid pressure control apparatus for a vehicle, or the like,
and is attached to a pressure room 32 in a housing 31. The film
portion 2 is flexibly deformed by operation of pressure, and
changes a volume of the pressure room 32 and open/close a vent hole
33.
[0006] In the above outlines of the diaphragm, recently, as
illustrated in FIG. 6(A), a diaphragm having a type, in which one
surface 2a in the thickness direction of the film portion 2 and one
end surface 3a in the thickness direction of the outer peripheral
flange portion 3 are arranged on the same plane, has been
developed. As illustrated in FIG. 6(B), the diaphragm 1 is attached
by which the outer peripheral flange portion 3 is sandwiched
between a pair of an upper housing 31A and a lower housing 31B. At
this time, the film portion 2 becomes, as an initial moving
attitude, a state in which one surface 2a of the film portion 2 is
in contact with a plane portion 35 of the housing 31A in the lower
side in FIG. 6(B), where the vent hole 33 is provided.
[0007] However, in the diaphragm 1 illustrated in FIGS. 6(A) and
6(B), the diaphragm 1 is largely pressed and deformed when the
outer peripheral flange portion 3 is inserted between the pair of
the housings 31A and 31B. Thus, as illustrated in FIG. 6(C), by
receiving the effect of the deformation, one surface 2a of the film
portion 2 may be separated and risen upward from the plane portion
35 of the lower side housing 31. In such a case, it is necessary to
prevent the rising upward of the film portion 2 and ensure an
accurate initial moving attitude.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
[0008] In view of the above problems, the present invention is
directed to provide a diaphragm enabling to prevent generation of
the rising upward phenomenon of the film portion when the diaphragm
is attached to the housing.
Means for Solving the Problems
[0009] For obtaining the above object, the first aspect of the
diaphragm in the present invention is that the diaphragm includes a
flexible film portion and an outer peripheral flange portion
integrally provided on a peripheral edge of the film portion. The
outer peripheral flange portion is provided between and held by a
pair of a first housing and a second housing. The outer peripheral
flange portion includes a first pressed surface and a
three-dimensional shape composed of a projected portion and a
recessed portion. The first pressed portion is one surface of the
diaphragm in the thickness direction and is in close contact with
the first housing. When the outer peripheral flange portion is
attached to the first housing and the second housing while being
compressed and deformed therebetween, the three-dimensional shape
defines voids in the thickness direction between the outer
peripheral flange portion and the first housing.
[0010] The diaphragm according to the present invention includes
the flexible film portion and the outer peripheral flange portion
integrally provided on the peripheral edge of the film portion.
When the outer peripheral flange portion is provided between and
held by a pair of the first housing and the second housing, for
example, the diaphragm is used in an accumulator of the fluid
pressure control apparatus for a vehicle, or the like, the state in
which the film portion is seated in the first housing is set to be
an initial moving attitude. When a pressure difference between the
space between the first housing and the diaphragm and the space
between the diaphragm and the second housing is generated, the
diaphragm operates so as to separate the film portion from the
first housing. According to the first aspect, only making the first
pressed surface to have the three dimensional shape, voids in the
thickness direction can be defined between the outer peripheral
flange portion and the first housing. The voids in the thickness
direction absorbs the deformation by compression from the first
housing and the second housing of the outer peripheral flange
portion, so that the rising upward of the film portion from the
first housing generated by the effect of the deformation can be
prevented, when the diaphragm is attached between the first housing
and the second housing, i.e., in the initial moving attitude where
the pressure difference is not generated.
[0011] Further, the second aspect of the diaphragm in the present
invention is that, in the diaphragm according to the first aspect,
the three-dimension shape is an annular projection provided on a
center portion in the diameter direction of the first pressed
surface. When the outer peripheral flange portion is attached to
the first housing and the second housing while being compressed and
deformed therebetween, the voids in the thickness direction is
defined on the more outer side in the diameter direction than the
annular projection on the first pressed surface.
[0012] According to the second aspect, the voids in the thickness
direction is defined on the more outer side in the diameter
direction than the annular projection on the first pressed surface,
so that a space of the voids in the thickness direction can be
sufficiently secured by the annular projection. Thus, the
deformation by the compression from the first housing and the
second housing of the outer peripheral flange portion can be easily
absorbed.
[0013] Further, the third aspect of the diaphragm in the present
invention is that, in the diaphragm according to the first aspect
or second aspect, when the outer peripheral flange portion is
attached between the first housing and the second housing, the
outer peripheral flange portion is set to have the outer diameter
size which can define the voids in the diameter direction between
the outer peripheral surface of the outer peripheral flange portion
and at least one of the first housing or the second housing, in the
diameter direction of the diaphragm.
[0014] According to the third aspect, the absorption of the
deformation by the compression from the first housing and the
second housing becomes more easily by the voids in the diameter
direction.
[0015] Further, the fourth aspect of the diaphragm in the present
invention is that, in any one of the diaphragm according to the
first aspect or third aspect, the outer peripheral flange portion
includes a second pressed surface, which is another surface in the
thickness direction of the diaphragm and pressed by the second
housing, and a three-dimensional shape composed of a projected
portion or a recessed portion on the second pressed surface.
[0016] According to the fourth aspect, by only making the second
pressed surface to have the three-dimensional shape, the voids in
the thickness direction can be easily defined between the outer
peripheral flange portion and the second housing. Thus, the
deformation by the compression from the first housing and the
second housing can be more easily absorbed by the voids in the
thickness direction.
[0017] Furthermore, the fifth aspect of a supporting structure of
the diaphragm in the present invention is the diaphragm supporting
structure which holds the diaphragm by the first housing and the
second housing, and includes any one of diaphragm according to the
first aspect or fourth aspect as the diaphragm.
[0018] According to the fifth aspect, in the diaphragm supporting
structure, the rising upward of the film portion from the first
housing can be prevented by any one of the diaphragm according to
the first aspect or fourth aspect.
Effect of the Invention
[0019] The present invention has following effects.
[0020] That is, as described above, in the present invention, the
voids in the thickness direction and the voids in the diameter
direction are set around the outer peripheral flange portion and
refuges of the rubber-like elastic body are secured at the time of
deformation of the flange, so that the deformation of the flange
portion can be absorbed in the refuges to prevent the influence of
the deformation to reach the film portion in the inner peripheral
side. Therefore, the phenomenon of the rising upward of the film
portion can be prevented and the accurate initial moving attitude
can be secured.
BRIEF EXPLANATION OF DRAWINGS
[0021] FIG. 1 is a view illustrating a diaphragm according to an
example of the present invention. (A) is a half cross-sectional
view in the state before being attached and (B) is an enlarged view
of the essential part of (A).
[0022] FIG. 2 is a view illustrating the same diaphragm in FIG. 1.
(A) is a half cross-sectional view in the state being attached and
(B) is an enlarged view of the essential part of (A).
[0023] FIG. 3 is a view illustrating a diaphragm according to
another example of the present invention. (A) is a half
cross-sectional view in the state before being attached and (B) is
an enlarged view of the essential part of (A).
[0024] FIG. 4 is a view illustrating the same diaphragm in FIG. 3.
(A) is a half cross-sectional view in the state being attached and
(B) is an enlarged view of the essential part of (A).
[0025] FIG. 5 is a cross-sectional view illustrating the attached
state of a diaphragm according to a conventional example.
[0026] FIG. 6 is the diaphragm according to the comparative
example. (A) is a half cross-sectional view in the state before
being attached, (B) is an enlarged view of the essential part of
(A), and (C) is a half cross-sectional view in the defect
generation state.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0027] Then, the examples of the present invention will be
described, referring to figures.
[0028] As illustrated in FIG. 1 and FIG. 2, a diaphragm 1 according
to the present example is formed in a disk-like shape by a
predetermined rubber-like elastic body. The diaphragm integrally
includes a flexible film portion 2 and an annular outer peripheral
flange portion (outer peripheral attaching portion) 3 provided at a
peripheral edge of the film portion 2. Further, the diaphragm 1
according to the present examples is used for an accumulator of a
fluid pressure control apparatus for vehicles which performs ABS
control, ESC control, or the like. In the diaphragm 1, the outer
peripheral flange portion 3 is sandwiched by a pair of upper and
lower housings 31A and 31B to be attached to a pressure room 32
(refer to FIG. 2) in the housings 31A and 31B. A vent hole 33 is
provided in the lower side housing 31A in FIG. 1 and, at the upper
side housing 31B, fore example, a communication hole 39, which
communicates with a flow path of an operation fluid of the fluid
pressure control apparatus for vehicles, is provided.
[0029] As for a detailed structure of the diaphragm 1, the film
portion 2 is formed to be a flat plate having a uniform thickness
over the whole surface (however, the case when a thick portion
described below is provided is excepted). The film portion 2
includes one surface 2a facing to one housing 31A (a first
housing), in which the vent hole 33 is provided, and another
surface 2b in the opposite side. The outer peripheral flange
portion 3 is set to have a larger thickness than the film portion 2
and formed to have a cross-sectional approximately rectangular
shape. One end surface in the thickness direction of the outer
peripheral flange portion is set to be a pressed surface (a first
pressed surface) 3a with respect to the one housing 31A in which
the vent hole 33 is provided, and another end surface is set to be
a pressed surface (a second pressed surface) 31b pressed by the
another housing (a second housing) 31B. The first pressed surface
3a and the one surface 2a of the film portion 2 is arranged on the
same plane to be a flat surface. The second pressed surface 3b
protrudes more in the thickness direction than the another surface
2b of the film portion 2.
[0030] In addition, for preventing the film portion 2 to interfere
with the vent hole 33 (the film portion 2 is bitted into the vent
hole), a thick portion 4 having recessed part 5 is integrally
formed at the plane center of the film portion 2. Corresponding to
the thick portion 4, a recessed portion 34 for inserting the thick
portion 4 is provided around the opening of the vent hole 33 in the
one housing 31A. However, the thick portion 4 and the recessed
portion 34 are not indispensable configurations, so that these
portions can not be provided.
[0031] In the one housing 31A in which the above vent hole 33 is
provided, the plane portion 35, which is in contact with the
approximately whole surface of the one surface 2a of the film
portion 2, is provided. Between a pair of the housings 31A and 31B,
an annular attaching portion 36 (refer to FIG. 2) for attaching the
outer peripheral flange portion 3 of the diaphragm 1 is provided.
With this structure, in the one housing 31A, an annular step
portion 37 is provided to form an outer peripheral wall 36a of the
attaching portion 36 and, in the another housing 31B, an annular
stopper portion 38 having a projection shape is provided to form an
inner peripheral wall 36b of the attaching portion 36.
[0032] A size c of the attaching portion 36 in the thickness
direction (refer to FIG. 2) is set to be smaller than a size d of
the outer peripheral flange portion 3 in the thickness direction in
a free state (c<d) (refer to FIG. 1). In contrast, a size .phi.e
of the attaching portion 36 in the width direction (a diameter
direction) (refer to FIG. 2) is set to be larger than a size .phi.f
of the outer peripheral flange portion 3 in the width direction in
the free state (.phi.e>.phi.f) (refer to FIG. 1). Further, a
distance g between the plane portion 35 of the one housing 31A and
the stopper portion 38 of the another housing 31B (refer to FIG. 2)
is set to be the same as a thickness size h of the film portion 2
(refer to FIG. 1) or a little larger than the thickness size of the
film portion 2 (g.gtoreq.h).
[0033] Assuming these items mentioned above, when the diaphragm 1
is attached between a pair of the housings 31A and 31B, as
illustrated in FIG. 2, the state in which the film portion 2 is in
contact with the plane portion 35 of the one housing 31A by the one
surface 2a thereof becomes an initial moving attitude. When
pressure is applied to the diaphragm in the initial moving
attitude, the film portion 2 is separated from the plane portion 35
of the housing 31A. The outer peripheral flange portion 3 is
compressed and deformed when the diaphragm is attached between the
housings 31A and 31B, as illustrated from FIG. 1 to FIG. 2. Even
when the outer peripheral flange portion 3 is compressed and
deformed, it is an ideal form for the diaphragm to keep the state
in which the film portion 2 is in contact with the plane portion 35
of the housing 31A. However, as described above, depending on the
cross-sectional shape of the diaphragm 1, as illustrated in FIG.
6(C), the film portion 2 can be already separated and risen from
the planet portion 35 of the housing 31A in the initial moving
attitude in which the outer peripheral flange portion 3 is only
attached between the housings 31A and 31B. In such a case, the
countermeasure of this phenomenon is necessary.
[0034] Thus, the present inventors have reached the present
invention and propose the following examples according to the
present invention.
[0035] That is, as illustrated in FIG. 1, in the diaphragm 1
according to the examples, a three-dimensional shape 7 is provided
on a part of the plane of the first pressed surface 3a of the outer
peripheral flange portion 3. As illustrated in FIG. 2, the
three-dimensional shape 7 sets voids in the thickness direction 8
(which are illustrated in FIG. 2) between the outer peripheral
flange portion 3 and the one housing 31A. The voids in the
thickness direction 8 becomes a refuge space at a time of
deformation of the outer peripheral flange portion 3 and prevents
generation of the phenomenon of rising upward of the film portion 2
by the deformation of the outer peripheral flange portion 3, when
the outer peripheral flange portion 3 is attached between the
housings 31A and 31B and compressed and deformed.
[0036] More specifically, the three-dimensional shape 7 is provided
as a projection 9 provided at the center portion in the diameter
direction of the first compressed surface of 3a. By being provided
such the projection 9, the voids in the thickness direction 8 is
set, in the attached state of the diaphragm, on the outer periphery
side of the projection 9 and between the first pressed surface 3a
of the outer peripheral flange portion 3 and the bottom surface 36c
of the housing attaching portion 36. The projection 9 is formed in
a circle shape in a cross section cut by a plane containing a
center axis of the diaphragm illustrated in FIG. 1. In a plane view
viewing from the under side in FIG. 1, the projection 9 is annually
formed on the whole periphery of the first pressed surface 3a.
However, the shape in the plane view is not limited to the circle
shape but can be an arrangement in which a plurality of projections
are arranged on the first pressed surface 3a in the circumferential
direction, if there are no problems in the sealing ability.
[0037] Further, the outer peripheral flange portion 3 is set to
have the outer diameter size enabling to define voids in the
diameter direction 10 (which is illustrated in FIG. 2) between the
outer peripheral surface 3c of the outer peripheral flange portion
3 and the outer peripheral wall 36a of the housing attaching
portion 36, when the outer peripheral flange portion 3 is attached
between the housings 31A and 31B. On a part of the outer peripheral
surface 3c of the outer peripheral flange portion 3, projections
(not illustrated) can be provided and in contact with the outer
peripheral wall 36a of the housing attaching portion 36.
[0038] Further, although the second pressed surface 3b of the outer
peripheral flange portion 3 can be a flat surface, in this example,
a three-dimensional shape 11 in a part on the plane is also
provided on the second pressed surface 3b. More specifically, the
three-dimensional shape 11 is provided as a projection 12 at a
center portion in the diameter direction of the second pressed
surface 3b. By being provided such a projection 12, in the
attaching state, the voids in the thickness direction 13 is set on
the outer peripheral side of the projection 12 and between the
second pressed surface 3b of the outer peripheral flange portion 3
and a bottom surface 36d in the opposite side of the housing
attaching portion 36, as illustrated in FIG. 2. Similar to the
aforementioned projection 9, the projection 12 is formed to have a
circle shape in a cross section cut by a plane containing a center
axis of the diaphragm illustrated in FIG. 1. In a plane view
viewing from the upper and under sides in FIG. 1, the projection 12
is annually formed on the whole periphery of the second pressed
surface 3b. However, the shape of the plane view of the projection
12 is not limited to the circle shape but can be a structure in
which a plurality of projections are arranged in the
circumferential direction, if there are no problems in the sealing
ability.
[0039] According to the diaphragm 1 including the aforementioned
structure, the three-dimensional shape 7 in a part on the plane,
i.e., the projection 9, is provided on the first pressed surface 3a
of the outer peripheral flange portion 3. By this projection 9, the
voids in the thickness direction 8 is defined on the outer
peripheral side of the projection 9 and between the first pressed
surface 3a of the outer peripheral flange portion 3 and the bottom
surface 36c of the housing attaching portion 36. The voids in the
thickness direction 8_has a size enabling to absorb the elastic
deformation of the outer peripheral flange portion 3 by the
compression in the vertical direction illustrated in FIGS. 1 and 2,
when the diaphragm 1 is attached between the first housing 31A and
the second housing 31B. Therefore, even when the outer peripheral
flange portion 3 is compressed and deformed, the influence hardly
reaches to the film portion 2, so that the generation of rising
upward phenomenon of the film portion 2, which is illustrated in
FIG. 6(C), can be prevented. In addition, the voids in the
thickness direction 8 can be provided not only on the outer
peripheral side but also the inner peripheral side.
[0040] Further, in the present examples, the voids in the diameter
direction 10 are defined between the outer peripheral surface 3c of
the outer peripheral flange portion 3 and the outer peripheral wall
36a of the housing attaching portion 36 together with
aforementioned voids in the thickness direction 8. The voids in the
diameter direction 10 absorbs a part of the elastic deformation of
the outer peripheral flange portion 3 generated by the vertical
compression illustrated in FIGS. 1 and 2, when the diaphragm 1 is
attached between the first housing 31A and second housing 31B. By
adding the voids in the diameter direction 10 to the voids in the
thickness direction 8, the voids absorbing the elastic deformation
of the outer peripheral flange portion 3 can be more enlarged, and
the generation of the rising upward of the film portion 2 can be
more easily prevented.
[0041] Furthermore, in the present examples, together with the
aforementioned voids, the three-dimensional shape 11, i.e., the
projection 12 is also provided on the second pressed surface 3b of
the outer peripheral flange portion 3, so that the voids in the
thickness direction 13 is defined on the outer peripheral side of
the projection 12 and between the second pressed surface 3b and the
bottom surface 36b of the housing attaching portion 36. The voids
in the thickness direction 13 also absorbs a part of the elastic
deformation of the outer peripheral flange portion 3 by the
compression in the vertical direction illustrated in FIGS. 1 and 2,
when the diaphragm 1 is attached between the first housing 31A and
the second housing 31B. In addition to the voids in the thickness
direction 8 and the voids in the diameter direction 10, the voids
in the thickness direction 13 can enlarge more the voids absorbing
the elastic deformation of the outer peripheral flange portion 3,
so that the generation of rising upward of the film portion 2 can
be more easily prevented. In addition, the voids in the thickness
direction 13 can be defined not only on the outer peripheral side
of the projection 12 but also on the inner peripheral side of the
projection 12.
[0042] Further, as for the projected portion, such as, the
projections 9 and 12 which are the above voids three-dimensional
shapes 7 and 11, there is a case in which a plurality of projected
portions is respectively provided in parallel on the first pressed
surface 3a or the second pressed surface 3b of the outer peripheral
flange portion 3. In this case, the voids in the thickness
direction 8 and 13, which become the refuge of the rubber-like
elastic body, are set between the projections 9 and 12 each
other.
[0043] Further, the three-dimensional shape 7, 11 can be a recessed
portion instead of the projected portions, such as, the projections
9 and 12. In this case, voids 8 and 13, which become the refuge of
the rubber-like elastic body, are set between the outer peripheral
flange portion 3 and the bottom surfaces 36c and 36d of the housing
attaching portion 36, while being in the state that the first
pressed surface 3a or the second pressed surface 3b of the outer
peripheral flange portion 3 are directly in contact with the bottom
surface 36c or 36d of the housing attaching portion 36 and
compressed. There also can be a case in which a plurality of
recessed portions are arrange in parallel. In FIG. 3 and FIG. 4
illustrated as another example, the three-dimensional shape 11 in
the upper side in figures is formed on the second pressed surface
3b by a groove-shaped recessed portion 14, in the upper and lower
three-dimensional shapes 7 and 11.
[0044] In addition, the aforementioned each voids 8, 10, and 13 act
as the refuge of the rubber-like elastic body when the outer
peripheral flange portion 3 is sandwiched between the housings 31A
and 31B, and compressed and deformed. Thus, in the state when the
compression and deformation by attaching is completed (in the state
when the attaching operation is completed), there can be a case
that a part or the whole of the voids disappears (filled by the
rubber-like elastic body and does not exist as a space).
* * * * *