U.S. patent application number 13/257564 was filed with the patent office on 2012-02-23 for water-proof structure for opening of case of appliance.
This patent application is currently assigned to NOK CORPORATION. Invention is credited to Kota Henmi, Hideto Nameki.
Application Number | 20120043331 13/257564 |
Document ID | / |
Family ID | 45593265 |
Filed Date | 2012-02-23 |
United States Patent
Application |
20120043331 |
Kind Code |
A1 |
Nameki; Hideto ; et
al. |
February 23, 2012 |
WATER-PROOF STRUCTURE FOR OPENING OF CASE OF APPLIANCE
Abstract
In a water-proof structure for an opening of a device case,
which includes a packing installed in a peripheral groove around a
cover and compressed between the inner periphery of the opening and
the groove when the cover is inserted into the opening, the packing
is configured to have a flat contact surface in contact with the
bottom of the groove and have a cross section having a width larger
than the height, and the cross section of the packing also has a
flat bottom or an inner side to fit the groove bottom that is also
flat in a cross section while the outer side has a convex shape so
that the whole cross section has a D-shaped form, in order to
prevent degraded sealing capability or improper installation due to
twist of the packing in the groove.
Inventors: |
Nameki; Hideto; (Kumamoto,
JP) ; Henmi; Kota; (Aso, JP) |
Assignee: |
NOK CORPORATION
Tokyo
JP
|
Family ID: |
45593265 |
Appl. No.: |
13/257564 |
Filed: |
March 9, 2010 |
PCT Filed: |
March 9, 2010 |
PCT NO: |
PCT/JP2010/053825 |
371 Date: |
September 19, 2011 |
Current U.S.
Class: |
220/378 |
Current CPC
Class: |
H04M 1/0202 20130101;
H05K 5/061 20130101; F16J 15/062 20130101; F16J 15/3204 20130101;
H04M 1/18 20130101 |
Class at
Publication: |
220/378 |
International
Class: |
B65D 51/00 20060101
B65D051/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 8, 2009 |
JP |
2009-113544 |
Jun 30, 2009 |
JP |
2009-155369 |
Claims
1. A waterproof structure of an opening and closing portion of a
device case in which a packing is installed to an installation
groove which is peripherally provided in an outer peripheral
surface of a cover, and said packing is compressed between an inner
surface of an opening portion and a bottom surface of said
installation groove by fitting said cover to said opening portion
of the device case, wherein said packing has a flat shape at a
close contact surface with the bottom surface of said installation
groove, and a cross sectional diameter in a width direction of the
packing is made larger than a cross sectional diameter thereof in a
height direction.
2. A waterproof structure of an opening and closing portion of a
device case in which a packing is installed to an installation
groove which is peripherally provided in an outer peripheral
surface of a cover, and said packing is compressed between an inner
surface of an opening portion and a bottom surface of said
installation groove by fitting said cover to said opening portion
of the device case, wherein said packing has a flat cross sectional
shape at a close contact surface with the bottom surface of said
installation groove, that is, an inner peripheral surface in
accordance that said installation groove has a flat cross sectional
shape at its bottom surface, has a circular arc shaped convex
surface at an outer periphery surface at the opposite side, and is
formed to have a D-shaped cross section as a whole.
3. A waterproof structure of an opening and closing portion of a
device case in which a packing is installed to an installation
groove which is peripherally provided in an outer peripheral
surface of a cover, and said packing is compressed between an inner
surface of an opening portion and a bottom surface of said
installation groove by fitting said cover to said opening portion
of the device case, wherein a fitting groove extending in an
extending direction of said installation groove is formed in the
bottom surface of said installation groove, and a fitting
projection capable of fitting to said fitting groove is formed on
said packing.
4. The waterproof structure of an opening and closing portion of a
device case as claimed in claim 3, wherein said packing has a flat
cross sectional shape at a close contact surface with the bottom
surface of said installation groove, that is, an inner peripheral
surface in accordance that said installation groove has a flat
cross sectional shape at its bottom surface, has a circular arc
shaped convex surface at an outer periphery surface at an opposite
side, and is formed to have a D-shaped cross section as a whole,
and said fitting projection is formed on an inner peripheral
surface of said packing formed to have said D-shaped cross
section.
5. The waterproof structure of an opening and closing portion of a
device case as claimed in claim 3, wherein said packing is formed
to have a crucial cross sectional shape while having a fitting
projection at an inner peripheral side fitting to said fitting
groove, a seal projection at an outer peripheral side coming into
close contact with an inner surface of said opening portion, and
seal projections at both sides in a width direction, in accordance
that said installation groove has a flat cross sectional shape at
its bottom surface.
6. A waterproof structure of an opening and closing portion of a
device case in which a packing is installed to an installation
groove which is peripherally provided in an outer peripheral
surface of a cover, and said packing is compressed between an inner
surface of an opening portion and a bottom surface of said
installation groove by fitting said cover to said opening portion
of the device case, wherein said packing has a flat shape at a
close contact surface with the bottom surface of said installation
groove, and a close contact surface with an inner surface of said
opening portion is constructed by a peak portion and inclined
surfaces at both sides thereof.
7. A waterproof structure of an opening and closing portion of a
device case in which a packing is installed to an installation
groove which is peripherally provided in an outer peripheral
surface of a cover, and said packing is compressed between an inner
surface of an opening portion and a bottom surface of said
installation groove by fitting said cover to said opening portion
of the device case, wherein said packing has a flat cross sectional
shape at a close contact surface with the bottom surface of said
installation groove, that is, an inner peripheral surface in
accordance that said installation groove has a flat cross sectional
shape at its bottom surface, has a cross sectional shape provided
with a peak portion and inclined surfaces at both sides thereof at
an outer peripheral surface at the opposite side, and is formed to
have a pentagonal cross sectional shape as a whole.
8. The waterproof structure of an opening and closing portion of a
device case as claimed in claim 6, wherein the inclined surface at
a cover inserting direction side is a relatively gentle slope, and
the inclined surface at the opposite side to the cover inserting
direction is a relatively steep slope, in the inclined surfaces at
both sides of the peak portion of the packing.
9. The waterproof structure of an opening and closing portion of a
device case as claimed in claim 6, wherein the inclined surface at
a cover inserting direction side is a relatively gentle slope, and
the inclined surface at the opposite side to the cover inserting
direction is a relatively steep slope, in the inclined surfaces at
both sides of the peak portion of the packing, and the peak portion
of said packing is deviated from a center portion in the width
direction of the packing toward the opposite side to the cover
inserting direction.
10. The waterproof structure of an opening and closing portion of a
device case as claimed in claim 7, wherein the inclined surface at
a cover inserting direction side is a relatively gentle slope, and
the inclined surface at the opposite side to the cover inserting
direction is a relatively steep slope, in the inclined surfaces at
both sides of the peak portion of the packing.
11. The waterproof structure of an opening and closing portion of a
device case as claimed in claim 7, wherein the inclined surface at
a cover inserting direction side is a relatively gentle slope, and
the inclined surface at the opposite side to the cover inserting
direction is a relatively steep slope, in the inclined surfaces at
both sides of the peak portion of the packing, and the peak portion
of said packing is deviated from a center portion in the width
direction of the packing toward the opposite side to the cover
inserting direction.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage Application of
International application No. PCT/JP2010/053825 filed on Mar. 9,
2010, and published in Japanese as WO 2010128606 A1 on Nov. 11,
2010. This application claims priority to Japanese Application No.
2009-113544 filed May 8, 2009 and Japanese Application No.
2009-155269 filed Jun. 30, 2009. The disclosures of the above
applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Technical Field
[0003] The present invention relates to a structure for achieving
waterproofness of an opening and closing portion such as a
connector cover portion, a battery cover portion or the like in a
case of a device.
[0004] 2. Description of the Conventional Art
[0005] In a compact electronic device such as a cellular phone, a
digital camera or the like, there is a structure which is provided
with a connector connection portion and a battery insertion portion
for inputting and outputting data and charging, and a cover is
detachably fitted to an opening portion which is provided as the
connector connection portion or the battery insertion portion in
the device case. Further, a gap between the case opening portion
and the cover mentioned above has been conventionally sealed by an
O-ring, thereby achieving waterproofness.
[0006] FIG. 26 shows the conventional waterproof structure
mentioned above, reference numeral 100 denotes a case of a compact
electronic device, reference numeral 101 denotes an opening portion
which is provided in the case 100, and reference numeral 200
denotes a cover which is detachably fitted to the opening portion
101. An installation groove 201 is peripherally provided in an
outer peripheral surface of the cover 200, and an O-ring 202 is
installed to the installation groove 201. The O-ring 202 is a
packing which is made of a rubber-like elastic material having a
circular cross section, and is structured such as to achieve a
waterproof function by being interposed in a compressed state
between an inner surface (an inner peripheral surface) of the
opening portion 101 and a bottom surface of the installation groove
201 of the cover 200 in a state in which the cover 200 is fitted to
the opening portion 101 of the case 100 (refer, for example, to the
following patent documents).
[0007] However, in accordance with the conventional waterproof
structure, in a process of fitting the cover 200 to the opening
portion 101 as shown in FIG. 26(B) from a state in which the
opening portion 101 is opened by detaching the cover 200 as shown
in FIG. 26(A), the O-ring 202 is twisted by friction with the inner
surface of the opening portion 101 and the bottom surface of the
installation groove 201, and there is a risk that a sealing
performance (a waterproof performance) by the O-ring 202 is
deteriorated.
[0008] Further, at a time of winding the O-ring 202 in the
installation groove 201 of the cover 200, torsion tends to be
caused in the O-ring 202, and there is a risk that the sealing
performance (the waterproof performance) is deteriorated by poor
installation.
SUMMARY OF THE INVENTION
[0009] The present invention is made by taking the point mentioned
above into consideration, and a technical problem thereof is to
prevent reduction of a waterproof performance and poor installation
due to torsion of a packing within an installation groove.
MEANS FOR SOLVING THE PROBLEM
[0010] As a means for effectively solving the technical problem
mentioned above, a waterproof structure in accordance with the
first aspect of the present invention is a structure in which a
packing is installed to an installation groove which is
peripherally provided in an outer peripheral surface of a cover,
and the packing is compressed between an inner surface of an
opening portion and a bottom surface of the installation groove by
fitting the cover to the opening portion of a case of a device, the
structure being characterized in that the packing has a flat shape
at a close contact surface with the bottom surface of the
installation groove, and a cross sectional diameter in a width
direction of the packing is made larger than a cross sectional
diameter thereof in a height direction.
[0011] Further, a waterproof structure in accordance with the
second aspect of the present invention is a structure in which a
packing is installed to an installation groove which is
peripherally provided in an outer peripheral surface of a cover,
and the packing is compressed between an inner surface of an
opening portion and a bottom surface of the installation groove by
fitting the cover to the opening portion of a case of a device, the
structure being characterized in that the packing has a flat cross
sectional shape at a close contact surface with the bottom surface
of the installation groove, that is, an inner peripheral surface in
accordance that the installation groove has a flat cross sectional
shape at its bottom surface, has a circular arc shaped convex
surface at an outer periphery surface at the opposite side, and is
formed to have a D-shaped cross section as a whole.
[0012] Further, a waterproof structure in accordance with the third
aspect of the present invention is a structure in which a packing
is installed to an installation groove which is peripherally
provided in an outer peripheral surface of a cover, and the packing
is compressed between an inner surface of an opening portion and a
bottom surface of the installation groove by fitting the cover to
the opening portion of a case of a device, the structure being
characterized in that a fitting groove extending in an extending
direction of the installation groove is formed in the bottom
surface of the installation groove, and a fitting projection
capable of fitting to the fitting groove is formed on the
packing.
[0013] Further, a waterproof structure in accordance with the
fourth aspect of the present invention is the waterproof structure
of an opening and closing portion of a device case as described in
the third aspect mentioned above, the structure being further
characterized in that the packing has a flat cross sectional shape
at a close contact surface with the bottom surface of the
installation groove, that is, an inner peripheral surface in
accordance that the installation groove has a flat cross sectional
shape at its bottom surface, has a circular arc shaped convex
surface at an outer periphery at the opposite side, and is formed
to have a D-shaped cross section as a whole, and the fitting
projection is formed on an inner peripheral surface of the packing
formed to have the D-shaped cross section.
[0014] Further, a waterproof structure in accordance with the fifth
aspect of the present invention is the waterproof structure of an
opening and closing portion of a device case as described in the
third aspect mentioned above, the structure being further
characterized in that the packing is formed to have a crucial cross
sectional shape while having a fitting projection at an inner
peripheral side fitting to the fitting groove, a seal projection at
an outer peripheral side coming into close contact with an inner
surface of the opening portion, and seal projections at both sides
in a width direction, in accordance that the installation groove
has a flat cross sectional shape at its bottom surface.
[0015] Further, a waterproof structure in accordance with the sixth
aspect of the present invention is a structure in which a packing
is installed to an installation groove which is peripherally
provided in an outer peripheral surface of a cover, and the packing
is compressed between an inner surface of an opening portion and a
bottom surface of the installation groove by fitting the cover to
the opening portion of a case of a device, the structure being
characterized in that the packing has a flat shape at a close
contact surface with the bottom surface of the installation groove,
and a close contact surface with an inner surface of the opening
portion is constructed by a peak portion and inclined surfaces at
both sides thereof.
[0016] Further, a waterproof structure in accordance with the
seventh aspect of the present invention is a structure in which a
packing is installed to an installation groove which is
peripherally provided in an outer peripheral surface of a cover,
and the packing is compressed between an inner surface of an
opening portion and a bottom surface of the installation groove by
fitting the cover to the opening portion of a case of a device, the
structure being characterized in that the packing has a flat cross
sectional shape at a close contact surface with the bottom surface
of the installation groove, that is, an inner peripheral surface in
accordance that the installation groove has a flat cross sectional
shape at its bottom surface, has a shape provided with a peak
portion and inclined surfaces at both sides thereof at an outer
peripheral surface at the opposite side, and is formed to have a
pentagonal cross sectional shape as a whole.
[0017] Further, a waterproof structure in accordance with the
eighth aspect of the present invention is the waterproof structure
of an opening and closing portion of a device case as described in
the sixth or seventh aspect mentioned above, the structure being
further characterized in that the inclined surface at a cover
inserting direction side is a relatively gentle slope, and the
inclined surface at the opposite side to the cover inserting
direction is a relatively steep slope, in the inclined surfaces at
both sides of the peak portion of the packing.
[0018] Further, a waterproof structure in accordance with the ninth
aspect of the present invention is the waterproof structure of an
opening and closing portion of a device case as described in the
sixth or seventh aspect mentioned above, the structure being
further characterized in that the inclined surface at a cover
inserting direction side is a relatively gentle slope, and the
inclined surface at the opposite side to the cover inserting
direction is a relatively steep slope, in the inclined surfaces at
both sides of the peak portion of the packing, and the peak portion
of the packing is deviated from a center portion in the width
direction of the packing toward the opposite side to the cover
inserting direction.
[0019] In the waterproof structure in accordance with the first
aspect of the present invention having the structure mentioned
above, since the packing has the flat shape at the close contact
surface with the bottom surface of the installation groove, and the
cross sectional diameter in the width direction is set to be larger
than the cross sectional diameter in the height direction, seating
on the bottom surface of the installation groove is stabilized in
comparison with the conventional O-ring which tends to roll, and
the packing is hardly twisted even by being exposed to a load in
the twisting direction, whereby it is possible to effectively
prevent reduction of a waterproof performance.
[0020] Further, in the waterproof structure in accordance with the
second aspect of the present invention, since the packing has the
flat cross sectional shape at the close contact surface with the
bottom surface of the groove, that is, the inner peripheral surface
in accordance that the installation groove has the flat cross
sectional shape at its bottom surface, has the circular arc shaped
convex surface at the outer periphery surface at the opposite side,
and is formed to have the D-shaped cross section as a whole,
seating on the bottom surface of the installation groove is
stabilized in comparison with the conventional O-ring which tends
to roll, and the packing is hardly twisted even by being exposed to
a load in the twisting direction, whereby it is possible to
effectively prevent reduction of the waterproof performance.
[0021] Further, in the waterproof structure in accordance with the
third, fourth or fifth aspect of the present invention, since the
fitting projection formed on the packing is fitted to the fitting
groove formed in the bottom surface of the installation groove, the
packing is constrained within the installation groove in accordance
with the fitting, and the package is hardly twisted even by being
exposed to a load in the twisting direction, whereby it is possible
to effectively prevent reduction of the waterproof performance. In
accordance with the structure of the fourth aspect, since the inner
peripheral surface of the packing has the flat cross sectional
shape, seating on the bottom surface of the installation groove is
stabilized. In accordance with the structure of the fifth aspect,
since the seal projections protruding to both sides in the width
direction come into close contact with the bottom surface of the
installation groove, seating on the bottom surface of the
installation groove is stabilized. Further, since the width in the
axial direction of the seal projection at the outer peripheral side
coming into close contact with the inner surface of the opening
portion is set to be smaller than the width in the axial direction
of a whole of the packing, compressive reaction force in an
installed state is set to be smaller.
[0022] Further, in the waterproof structure in accordance with the
sixth aspect of the present invention, since the close contact
surface with the bottom surface of the installation groove in the
packing has the flat shape, seating on the bottom surface of the
installation groove is stabilized in comparison with the
conventional O-ring which tends to roll, and the packing is hardly
twisted even by being exposed to a load in the twisting direction,
whereby it is possible to effectively prevent the reduction of the
waterproof performance. Further, since the close contact surface
with the inner surface of the opening portion of the case is
constructed by the peak portion and the inclined surfaces at both
sides thereof, the compressive reaction force becomes smaller in
comparison with the structure in which the close contact surface
with the inner surface of the opening portion is formed into the
circular arc shaped convex surface, in the case that a collapsing
margin is fixed, whereby it is possible to reduce press-fit
resistance at a time of fitting the cover to the opening portion of
the case, and abrasion of the packing. Therefore, it is possible to
prevent poor installation of the packing and torsion of the packing
within the groove on the basis of repeated opening and closing
motions of the cover or the like, it is further possible to reduce
the press-fit resistance at a time of fitting the cover to the
opening portion of the case, and it is possible to suppress
reduction of the waterproof performance due to the abrasion.
[0023] Further, in the waterproof structure in accordance with the
seventh aspect of the present invention, since the packing has the
flat cross sectional shape at the close contact surface with the
bottom surface of the installation groove, that is, the inner
peripheral surface in accordance that the installation groove has
the flat cross sectional shape at its bottom surface, seating on
the bottom surface of the installation groove is stabilized in
comparison with the conventional O-ring which tends to roll, and
the packing is hardly twisted even by being exposed to a load in
the twisting direction, whereby it is possible to effectively
prevent the reduction of the waterproof performance. Further, since
the packing has the cross sectional shape provided with the peak
portion and the inclined surfaces at both sides thereof at the
outer peripheral surface at the opposite side to the inner
peripheral surface, and is formed to have the pentagonal cross
sectional shape as a whole, the compressive reaction force becomes
smaller in comparison with the structure in which the close contact
surface with the inner surface of the opening portion is formed
into the circular arc shaped convex surface, in the case that a
collapsing margin is fixed, whereby it is possible to reduce
press-fit resistance at a time of fitting the cover to the opening
portion of the case, and abrasion of the packing. Therefore, it is
possible to prevent poor installation of the packing and torsion of
the packing within the groove on the basis of repeated opening and
closing motions of the cover or the like, it is further possible to
reduce the press-fit resistance at a time of fitting the cover to
the opening portion of the case, and it is possible to suppress
reduction of the waterproof performance due to the abrasion.
[0024] Further, in the waterproof structure in accordance with the
eighth or ninth aspect of the present invention, friction
resistance of the packing with the inner surface of the opening
portion of the case becomes smaller in a cover inserting direction
and larger in the opposite direction thereto. Further, since
surface pressure of the packing with respect to the inner surface
of the opening portion of the case more rapidly rises at the
opposite side to the cover inserting direction than the peak
portion, resistance against intruding pressure of water from the
external is increased. Accordingly, the cover can be fitted easier
to the opening portion of the case, the cover can be firmly fitted
so as to hardly fall away from the opening portion of the case, and
it is possible to further improve the waterproof performance.
BRIEF DESCRIPTION OF DRAWINGS
[0025] FIG. 1 is a perspective view showing a first embodiment of a
waterproof structure of an opening and closing portion of a device
case in accordance with the present invention;
[0026] FIG. 2 shows a state in which a packing is installed to a
groove in the first embodiment, in which FIG. 2(A) is a front view
and FIG. 2(B) is a side view in which a part of the packing is
cut;
[0027] FIG. 3 shows an example of the packing in accordance with
the first embodiment, in which FIG. 3(A) is a front view and FIG.
3(B) is a cross sectional view along a line B-B in FIG. 3(A);
[0028] FIG. 4 is a cross sectional view showing a part of the
packing in FIG. 3 in an enlarged manner;
[0029] FIG. 5 is a cross sectional view showing in an enlarged
manner a state in which a cover is fitted to an opening portion of
a case, in the first embodiment;
[0030] FIG. 6 is an explanatory view showing a process of fitting
the cover to the opening portion of the case, in the first
embodiment;
[0031] FIG. 7 is a cross sectional view of a substantial part
showing a second embodiment of the waterproof structure of the
opening and closing portion of the device case in accordance with
the present invention;
[0032] FIG. 8 shows a state in which a packing is installed to a
groove in the second embodiment, in which FIG. 8(A) is a front view
and FIG. 8(B) is a side view in which a part of the packing is
cut;
[0033] FIG. 9 shows the packing in accordance with the second
embodiment, in which FIG. 9(A) is a front view and FIG. 9(B) is a
cross sectional view along a line B-B' in FIG. 9(A);
[0034] FIG. 10 is a perspective view showing a state in which the
packing is installed to a packing installation groove, in the
second embodiment;
[0035] FIG. 11 is a cross sectional view of a substantial part
showing a third embodiment of the waterproof structure of the
opening and closing portion of the device case in accordance with
the present invention;
[0036] FIG. 12 is a cross sectional view showing shapes of a cover
and a packing in the third embodiment;
[0037] FIG. 13 is a perspective view showing a state in which the
packing is installed to a packing installation groove in the third
embodiment;
[0038] FIG. 14 is a perspective view showing a fourth embodiment of
the waterproof structure of the opening and closing portion of the
device case in accordance with the present invention;
[0039] FIG. 15 is a cross sectional perspective view showing a
state in which a packing is installed to a groove in the fourth
embodiment;
[0040] FIG. 16 shows an example of a cover to which the packing is
installed, in the fourth embodiment, in which FIG. 16(A) is a plan
view, FIG. 16(B) is a back view, and FIG. 16(C) is a side view;
[0041] FIG. 17 shows the other example of the cover to which the
packing is installed, in the fourth embodiment, in which FIG. 17(A)
is a plan view, FIG. 17(B) is a back view, and FIG. 17(C) is a side
view;
[0042] FIG. 18 is a cross sectional view showing a concrete example
of the packing in accordance with the fourth embodiment;
[0043] FIG. 19 is an explanatory view showing a process of fitting
the cover to an opening portion of a case in the fourth
embodiment;
[0044] FIG. 20 is a cross sectional perspective view showing a
state in which a packing is installed to a groove, in a fifth
embodiment of the waterproof structure of the opening and closing
portion of the device case in accordance with the present
invention;
[0045] FIG. 21 is a cross sectional view showing an example of the
packing in accordance with the fifth embodiment;
[0046] FIG. 22 is an explanatory view showing a process of fitting
a cover to an opening portion of a case, in the fifth
embodiment.
[0047] FIG. 23 is an explanatory view showing surface pressure
distribution of the packing in the fifth embodiment;
[0048] FIG. 24 is a cross sectional perspective view showing a
state in which a packing is installed to a groove, in a sixth
embodiment of the waterproof structure of the opening and closing
portion of the device case in accordance with the present
invention;
[0049] FIG. 25 is a cross sectional view showing an example of the
packing in accordance with the sixth embodiment; and
[0050] FIG. 26 is an explanatory view showing a process of fitting
a cover to an opening portion of a case in a waterproof structure
of an opening and closing portion of a device case in accordance
with a conventional art.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] A description will be given below of preferable embodiments
of a waterproof structure of an opening and closing portion of a
device in accordance with the present invention with reference to
the accompanying drawings.
First Embodiment
[0052] First of all, in a perspective view of FIG. 1, reference
numeral 1 denotes a case of a compact electronic device, and
reference numeral 2 denotes a cover which is detachably fitted to
an opening portion 11 provided in the case 1.
[0053] The opening portion 11 provided in the case 1 is structured
such that an opening shape is formed as a square shape having round
corners. In other words, an inner peripheral surface thereof has
flat surface portions and curved surface portions alternately in a
peripheral direction.
[0054] The cover 2 is formed in a tabular shape as a whole, and has
an insertion portion 21 which can be inserted to the opening
portion 11 of the case 1, and a collar portion 22 which is formed
so as to protrude out of an outer end portion of the insertion
portion 21 and is opposed to an outer surface 1a of the case 1, as
shown in FIG. 5.
[0055] An outer peripheral surface 21a of the insertion portion 21
of the cover 2 is formed in its projection shape in an inserting
direction, to have an approximately similar shape to the opening
shape of the opening portion 11 of the case 1, that is, a square
shape having round corners as shown in FIG. 2, has flat surface
portions and curved surface portions alternately in a peripheral
direction, and is a little smaller than the opening portion 11.
Further, an installation groove (also called simply as "groove",
and also called as "packing installation groove") 23 is
peripherally provided in an outer peripheral surface 21a of the
insertion portion 21, and the installation groove 23 is formed to
have an approximately C-shaped cross section, that is, is
constructed by a flat surface shaped bottom surface 23a which is in
parallel to the outer peripheral surface 21a of the insertion
portion 21, and a pair of inner surfaces 23b which vertically rise
from both sides thereof.
[0056] A packing 3 made of a rubber-like elastic material (a rubber
material or a synthetic resin material having a rubber-like
elasticity) is installed to the installation groove 23 mentioned
above. The packing 3 is molded in an annular shape as shown in FIG.
3(A), and a cross section thereof has a D-shape as shown in FIG.
3(B). In more detail, in a cross sectional shape shown in FIG. 4
and FIG. 5, an inner peripheral surface 3a coming into close
contact with a bottom surface 23a of the installation groove 23 has
a flat shape, and an outer peripheral surface 3b which protrudes to
an outer side of the installation groove 23 so as to be brought
into pressure contact with an inner surface of the opening portion
11 of the case 1 in an appropriate deformed state is formed into a
circular arc shaped convex surface. In this case, the inner
peripheral surface 3a of the packing 3 corresponds to the close
contact surface described in the first aspect.
[0057] Further, as shown in FIG. 4, a cross sectional diameter L1
in a width direction of the packing 3 is larger than a cross
sectional diameter L2 in a height direction, that is, a relation of
L2/L1<1 is established. In this case, L2 is larger than a depth
of the installation groove 23.
[0058] In the structure mentioned above, the cover 2 is structured
such that the insertion portion 21 thereof is press fitted to the
opening portion 11 of the case 1 via the packing 3, and the packing
3 is held in a state of being appropriately compressed between the
bottom surface 23a of the installation groove 23 and the inner
peripheral surface 11a of the opening portion 11, thereby closing
the opening portion 11 in a sealed state so as to achieve
waterproofness.
[0059] Further, in accordance with the present invention, since the
inner peripheral surface 3a brought into close contact with the
bottom surface 23a of the installation groove 23 is flat and the
relation of L2/L1<1 is established, in the packing 3, resistance
at a time when force in a rolling (twisting) direction acts is
large. Accordingly, the packing 3 is not twisted on the basis of
friction with the inner peripheral surface 11a of the opening
portion 11 and the bottom surface 23a of the installation groove
23, in a process of fitting the cover 2 to the opening portion 11
as shown in FIG. 6(B) from a state in which the opening portion 11
is open as shown in FIG. 6(A), and an excellent sealing performance
(a waterproof performance) by the packing 3 is secured.
[0060] Further, since the packing 3 is molded in an annular shape
as shown in FIG. 3, the conventional O-ring tends to be twisted at
a time of being fitted onto the insertion portion 21 of the
noncircular cover 2 having the flat portions and the curved surface
portions alternately in the peripheral direction as shown in FIG. 1
and FIG. 2 so as to be wound in the groove 23. However, in
accordance with the present invention, since the packing 3 has the
cross sectional shape as shown in FIG. 4 so as to be hardly
twisted, it is possible to effectively prevent the sealing
performance (the waterproof performance) from being deteriorated by
poor installation.
Second Embodiment
[0061] Next, FIG. 7 to FIG. 10 show a second embodiment in
accordance with the present invention.
[0062] In FIG. 7 among them, reference numeral 1 denotes a case of
a compact electronic device such as a cellular phone or the like,
and reference numeral 2 denotes a cover which is detachably fitted
to an opening portion 11 which is provided as a connector insertion
portion or the like in the case 1. The opening portion 11 of the
case 1 has a square shape having round corners in its opening
shape, that is, an inner peripheral surface 11a thereof has flat
surface portions and curved surface portions alternately in a
peripheral direction. The cover 2 is formed in a tabular shape as a
whole, and has an insertion portion 21 which can be inserted to the
opening portion 11 of the case 1, and a collar portion 22 which is
formed so as to protrude out of an outer end portion of the
insertion portion 21 and is opposed to an outer surface 12 of the
case 1.
[0063] An outer peripheral surface 21a of the insertion portion 21
of the cover 2 has, in its projection shape with respect to an
inserting direction, an approximately similar shape to the opening
shape of the opening portion 11 of the case 1, that is, a square
shape having round corners as shown in FIG. 8, has flat surface
portions and curved surface portions alternately in a peripheral
direction, and is a little smaller than the opening portion 11.
Further, an installation groove 23 is peripherally provided in an
outer peripheral surface 21a of the insertion portion 21 of the
cover 2, and a packing 3 is installed to the installation groove
23.
[0064] The installation groove 23 is constructed by a bottom
surface 23a which has a flat cross sectional shape and is in
parallel to the outer peripheral surface 21 a of the insertion
portion 21 of the cover 2, and a pair of inner surfaces 23b which
approximately vertically rise from both sides thereof, and a
fitting groove 24 which extends in an extending direction of the
installation groove 23 and has a C-shaped cross sectional shape is
formed at an intermediate position in a width direction of the
bottom surface 23a.
[0065] The packing 3 is molded in an annular shape as shown in FIG.
9(A) by a rubber-like elastic material (a rubber material or a
synthetic resin material having a rubber-like elasticity), and is
constructed by a main body portion 31 which has a D-shaped cross
section, and a fitting projection 32 which is formed on an inner
peripheral surface 31 a thereof, as shown in FIG. 9(B) and FIG.
10.
[0066] In detail, the main body portion 31 of the packing 3 is
retained within the installation groove 23, the inner peripheral
surface 31a brought into close contact with the bottom surface 23a
of the installation groove 23 has a flat cross sectional shape, an
outer peripheral surface 31b protruding out to an outer side of the
installation groove 23 so as to be brought into pressure contact
with the inner peripheral surface 11a of the opening portion 11 of
the case 1 in an appropriate deformed state is formed into a convex
surface having a circular arc shaped cross section, and slight gaps
are provided with respect to the inner surfaces 23b of the
installation groove 23 so that a filling rate of the main body
portion 31 within the installation groove 23 does not become 100%
or more even in a state of being compressed between the bottom
surface 23a of the installation groove 23 and the inner peripheral
surface 11a of the opening portion 11. Further, the fitting
projection 32 is structured such as to be brought into close
contact with and fitted to a fitting groove 24 formed in the bottom
surface 23a of the installation groove 23.
[0067] In the waterproof structure in accordance with the second
embodiment structured as mentioned above, as shown in FIG. 7, the
insertion portion 21 of the cover 2 is press fitted into the
opening portion 11 of the case 1 via the packing 3 and the main
body portion 31 of the packing 3 is held in a state of being
appropriately compressed between the bottom surface 23a of the
installation groove 23 and the fitting groove 24, and the inner
peripheral surface 11a of the opening portion 11, whereby the cover
2 closes the opening portion 11 in a sealed state so as to achieve
waterproofness.
[0068] Further, since the packing 3 is bound by the fitting
projection 32 being brought into close contact with and fitted to
the fitting groove 24 formed in the bottom surface 23a of the
installation groove 23, resistance at a time when force F in a
rolling (twisting) direction shown in FIG. 10 acts is large.
Therefore, the packing 3 (the main body portion 31) is not twisted
by friction with the inner peripheral surface 11a of the opening
portion 11 and the bottom surface 23a of the installation groove 23
in a process of fitting the cover 2 to the opening portion 11, and
an excellent sealing performance (a waterproof performance) is
secured.
[0069] Further, if the fitting projection 32 is pushed into the
fitting groove 24 of the bottom surface 23a of the installation
groove 23 while pressing the main body portion 31 lightly, at a
time of fitting the packing 3 onto the insertion portion 21 of the
noncircular cover 2 so as to wind it in the installation groove 23,
the fitting projection 32 is fitted into the fitting groove 24
sequentially. Accordingly, torsion of the packing 3 (the main body
portion 31) is not caused, and it is possible to effectively
prevent the sealing performance (the waterproof performance) from
being deteriorated by poor installation.
Third Embodiment
[0070] Next, FIG. 11 to FIG. 13 show a third embodiment in
accordance with the present invention. In this third embodiment, a
difference from the previously described second embodiment is cross
sectional shapes of the fitting groove 24 and the packing 3.
[0071] In more detail, the fitting groove 24 formed at an
intermediate position in a width direction of the bottom surface
23a of the installation groove 23 has an approximately U-shaped
cross section, as shown in FIG. 12 and FIG. 13.
[0072] Further, the packing 3 has an inner peripheral side fitting
projection 32 which has a convex surface having a circular arc
shaped cross section corresponding to the fitting groove 24, an
outer peripheral side seal projection 33 having a cross sectional
shape which is 180 degree symmetrical with the fitting projection
32, and seal projections 34 and 35 at both sides in a width
direction having cross sectional shapes which are 90 degree
symmetrical with the fitting projection 32 in 90 degree different
directions from the fitting projection 32 and the seal projection
33 respectively, in a cross section shown in FIG. 11 and FIG. 12,
that is, the packing 3 has an approximately crucial cross sectional
shape.
[0073] Further, the fitting projection 32 of the packing 3 is
brought into close contact with and fitted to a fitting groove 24
formed in the bottom surface 23a of the installation groove 23, and
the seal projection 33 at the outer peripheral side protrudes to
the outer side of the installation groove 23 so as to be brought
into pressure contact with the inner peripheral surface 11a of the
opening portion 11 of the case 1 in an appropriate deformed state.
Further, the seal projections 34 and 35 at both sides in the width
direction are brought into close contact with the inner surfaces
23b and 23b of the installation groove 23 at their top ends as well
as being retained within the installation groove 23, and their
inner peripheral portions are brought into close contact with the
bottom surface 23a of the installation groove 23. Since they have a
convex surface having a circular arc shaped cross section, slight
gaps are formed with respect to the bottom surface 23a and the
inner surfaces 23b of the installation groove 23, and a filling
rate of the packing 3 within the installation groove 23 does not
become 100% or more.
[0074] In the waterproof structure in accordance with the third
embodiment constructed as mentioned above, as shown in FIG. 11, the
cover 2 is structured such that the insertion portion 21 is press
fitted into the opening portion 11 of the case 1 via the packing 3
and the packing 3 is held in a state of being appropriately
compressed between the bottom surface 23a of the installation
groove 23 and the fitting groove 24, and the inner peripheral
surface 11a of the opening portion 11, thereby closing the opening
portion 11 in a sealed state so as to achieve waterproofness.
[0075] Further, since the packing 3 is structured such that the
fitting projection 32 at the inner peripheral side is brought into
close contact with and fitted to the fitting groove 24 formed in
the bottom surface 23a of the installation groove 23, and the top
ends of the seal projections 34 and 35 at both sides in the width
direction are brought into close contact with the inner surfaces
23b and 23b of the installation groove 23, resistance at a time
when force F in the rolling (twisting) direction shown in FIG. 13
acts is large, whereby the packing 3 is not twisted on the basis of
friction with the inner peripheral surface 11a of the opening
portion 11 and the bottom surface 23a of the installation groove 23
in a process of fitting the cover 2 to the opening portion 11, and
an excellent sealing performance (waterproof performance) can be
secured.
[0076] Further, if the fitting projection 32 is pressed into the
fitting groove 24 of the bottom surface 23a of the installation
groove 23 while pushing lightly the seal projections 33 to 35 at a
time of fitting the packing 3 onto the insertion portion 21 of the
noncircular cover 2 so as to wind it in the installation groove 23,
the fitting projection 32 is fitted into the fitting groove 24
sequentially. Accordingly, torsion of the packing 3 (the main body
portion 31) is not caused, and it is possible to effectively
prevent the sealing performance (the waterproof performance) from
being deteriorated by poor installation.
[0077] In this case, in the present invention, the fitting
projection 32 may not be necessarily continuous in an endless shape
in the extending direction of the packing 3, but may be
intermittent. In accordance with this, it is not necessary to carry
out the work of fitting the fitting projection 32 to the
installation groove 24 all over the periphery at a time of
installing the packing 3, and it is possible to prevent air from
being included in the fitting groove 24.
Fourth Embodiment
[0078] Next, FIG. 14 to FIG. 19 show a fourth embodiment in
accordance with the present invention. In a perspective view in
FIG. 14 among them, reference numeral 1 denotes a case of a compact
electronic device, and reference numeral 2 denotes a cover which is
detachably fitted to an opening portion 11 for inserting a battery
or connecting a connector, provided in the case 1.
[0079] The opening portion 11 provided in the case 1 is structured
such that an opening shape is, for example, a square shape having
round corners such as an example in FIG. 14, or an elliptic shape
(not shown). In other words, an inner peripheral surface 11a
thereof has flat surface portions and curved surface portions
alternately in a peripheral direction.
[0080] The cover 2 has a tabular shape as a whole, and has an
insertion portion 21 which can be inserted to the opening portion
11 of the case 1, and a collar portion 22 which is formed so as to
protrude out of an outer end portion of the insertion portion 21
and is opposed to an outer surface 1a of the case 1.
[0081] The insertion portion 21 of the cover 2 is formed, in its
projection shape with respect to an inserting direction, in an
approximately similar shape to the opening shape of the opening
portion 11 of the case 1, for example, a square shape having round
corners as an example shown in FIG. 16, an elliptic shape as an
example shown in FIG. 17 and the like, that is, has flat surface
portions and curved surface portions alternately in a peripheral
direction, and is a little smaller than the opening portion 11.
Further, an installation groove 23 is peripherally provided in an
outer peripheral surface 21a of the insertion portion 21 as shown
in FIG. 15 and FIG. 16, and the installation groove 23 has an
approximately C-shaped cross section, that is, is constructed by a
flat shaped bottom surface 23a which is in parallel to the outer
peripheral surface 21a of the insertion portion 21, and a pair of
inner surfaces 23b which vertically rise from both sides
thereof.
[0082] A packing 3 made of a rubber-like elastic material (a rubber
material or a synthetic resin material having a rubber-like
elasticity) is installed to the installation groove 23 of the cover
2.
[0083] The packing 3 is molded in an annular shape so as to have a
pentagonal cross sectional shape. As shown in FIG. 18, a height h
in a radial direction is larger than a depth d of the installation
groove 23, an inner peripheral surface 3a brought into close
contact with a bottom surface of the installation groove 23 has a
flat shape, both side surfaces 3c and 3d rising from both ends in
the width direction thereof have a vertical flat shape with respect
to the inner peripheral surface 3a, and an outer peripheral surface
which protrudes to an outer side of the installation groove 23 so
as to be brought into pressure contact with an inner surface of the
opening portion 11 of the case 1 in an appropriate deformed state
is constructed by a peak portion 3e, and inclined surfaces 3f and
3g which extend toward both the side surfaces 3c and 3d from the
peak portion 3e. The peak portion 3e is positioned at the center in
the width direction of the packing 3, and slopes of the inclined
surfaces 3f and 3g at both sides of the peak portion 3e are equal
to each other. In this case, the inner peripheral surface 3a
corresponds to "close contact surface with the bottom surface of
the installation groove" described in claim the sixth or seventh
aspect.
[0084] In a concrete example shown in FIG. 18, the packing 3 is
structured such that a width w is about 1.1 mm, and a height h is
about 1.0 mm, that is, a relation of h/w<1 is established.
Further, an angle .theta. formed by both the inclined surfaces 3f
and 3g is about 74 degree, the peak portion 3e is chamfered so as
to have a rounded surface in which a radius of curvature is about
0.3 mm, and the corner portions between the inner peripheral
surface 3a and the side surfaces 3c and 3d and the corner portions
between the side surfaces 3c and 3d and the inclined surfaces 3f
and 3g are chamfered respectively so as to have rounded surfaces in
which a radius of curvature is about 0.2 mm.
[0085] In the fourth embodiment structured as mentioned above, the
cover 2 is structured such that the insertion portion 21 is press
fitted to the opening portion 11 of the case 1 via the packing 3
and the packing 3 is held in a state of being appropriately
compressed between the bottom surface 23a of the installation
groove 23 and the inner surface 11a of the opening portion 11,
thereby closing the opening portion 11 in a sealed state so as to
achieve waterproofness.
[0086] Further, in the packing 3, since the inner peripheral
surface 3a brought into close contact with the bottom surface 23a
of the installation groove 23 has the flat shape, resistance at a
time when force in a rolling (twisting) direction acts is large,
and friction resistance with respect to the inner surface 11a of
the opening portion 11 on the basis of compressive reaction force
is small in addition as mentioned below. Accordingly, the packing 3
is not twisted in a process of fitting the cover 2 to the opening
portion 11 as shown in FIG. 19(B) from a state in which the opening
portion 11 is open as shown in FIG. 19(A), whereby an excellent
sealing performance (waterproof performance) by the packing 3 is
secured. Further, since the relation of h/w<1 is established in
the illustrated embodiment, this effectively contributes to the
torsion prevention of the packing 3.
[0087] Further, in this packing 3, the compressive reaction force
becomes smaller, in comparison with the packing 3 having the
D-shaped cross section, that is, having the convex surface in the
circular arc cross sectional shape at its outer peripheral surface
3b, which is described previously and shown in FIG. 4. This is
because a volume of the outer peripheral portion in the packing 3
in accordance with the present embodiment in which the outer
peripheral surface is constructed by the peak portion 3e and the
inclined surfaces 3f and 3g at both sides thereof is smaller, in
comparison with the packing 3 in which the outer peripheral surface
is formed into the circular arc shaped convex surface, as shown by
a single dot chain line in FIG. 18, in the case that the height h
is fixed, whereby an amount of compression becomes smaller in
comparison with the packing 3 having the D-shaped cross section if
a collapsing margin .delta. is fixed. Accordingly, friction
resistance of the packing 3 with respect to the inner surface 11a
of the opening portion 11 becomes smaller, and it is possible to
reduce press-fit resistance at a time of fitting the cover 2 to the
opening portion 11 as shown in FIG. 19(B) and abrasion of the
packing 3.
[0088] Further, since the inner peripheral surface 3a brought into
close contact with the bottom surface 23a of the installation
groove 23 has the flat shape as mentioned above, the packing 3 is
hardly twisted even in the installing process to the installation
groove 23, whereby it is possible to effectively prevent the
sealing performance (the waterproof performance) from being
deteriorated by poor installation.
Fifth Embodiment
[0089] Next, FIG. 20 to FIG. 23 show a fifth embodiment in
accordance with the present invention.
[0090] In this fifth embodiment, a difference from the fourth
embodiment mentioned above exists in a matter that the peak portion
3e of the packing 3 is deviated from the center in the width
direction toward the opposite side to the cover inserting direction
(a side of the collar portion 22 of the cover), as shown in FIG. 20
and FIG. 21. In other words, a distance L3 in an axial direction
between the peak portion 3e and the side surface 3c at the cover
inserting direction side is larger than a distance L4 in an axial
direction between the peak portion 3e and the side surface 3d at
the opposite side to the cover inserting direction, and a slope
.alpha. of the the inclined surface 3f at the cover inserting
direction side is a relatively gentle slope, and a slope .beta. of
the inclined surface 3g at the opposite side to the cover inserting
direction is a relatively steep slope, that is, a relation of a
.alpha.<.beta. is established in the inclined surfaces 3f and 3g
at both sides of the peak portion 3e. The other portions can be
structured basically the same as the fourth embodiment.
[0091] Therefore, in accordance with this structure mentioned
above, similarly to the fourth embodiment, it is possible to
effectively prevent torsion of the packing 3, and it is possible to
reduce abrasion of the packing 3.
[0092] Further, since the friction resistance of the packing 3 with
respect to the inner surface 11a of the opening portion 11 of the
case 1 becomes smaller in the cover inserting direction on the
basis of the relation of .alpha.<.beta., press-fit resistance at
a time of fitting the cover 2 to the opening portion 11 as shown in
FIG. 22(B) from a state in which the opening portion 11 of the case
1 is open as shown in FIG. 22(A) is further reduced. In addition,
since the friction resistance becomes larger in the opposite
direction to the cover inserting direction, the cover 2 hardly fall
away by accident from the opening portion 11.
[0093] Further, since the peak portion 3e of the packing 3 is
deviated from the center in the width direction toward the opposite
side to the cover inserting direction, surface pressure P with
respect to the inner surface 11a of the opening portion 11 of the
case 1 is distributed so as to rapidly rise at the opposite side to
the cover inserting direction, as shown in FIG. 23. Therefore,
resistance against pressure of intrusion of water or the like from
the external is increased, and it is possible to further enhance
the waterproof performance.
[0094] In this case, since there is a risk that the sealing
performance is lowered and smooth opening and closing of the cover
2 become hard, if an offset amount of the peak portion 3e of the
packing 3 is too large, it is desirable to set a ratio of L3:L4
within a range between 1:1 and 5:1.
Sixth Embodiment
[0095] Next, FIG. 24 and FIG. 25 shows a sixth embodiment in
accordance with the present invention.
[0096] In this sixth embodiment, the peak portion 3e is positioned
at the center in the width direction of the packing 3, a slope
.alpha. of the inclined surface 3f at the cover inserting direction
side is a relatively gentle slope, and a slope .beta. of the
inclined surface 3g at the opposite side to the cover inserting
direction is a relatively steep slope, that is, a relation of
.alpha.<.beta. is established in the inclined surfaces 3f and 3g
at both sides of the peak portion 3e. Therefore, in accordance with
the difference of the slopes .alpha. and .beta., a skirt portion 3h
of the inclined surface 3g at the opposite side to the cover
inserting direction is formed in a concave surface shape. The other
portions can be structured basically the same as the fifth
embodiment.
[0097] Further, in accordance with this structure, similarly to the
fifth embodiment, it is possible to reduce abrasion of the packing
3 as well as effectively preventing torsion of the packing 3.
Further, the same effect as the fifth embodiment can be obtained on
the basis of the relation of .alpha.<.beta.. In other words, the
friction resistance of the packing 3 with respect to the inner
surface 11a of the opening portion 11 of the case 1 becomes smaller
in the cover inserting direction and becomes larger in the opposite
direction to the cover inserting direction. In addition, surface
pressure with respect to the inner surface 11a of the opening
portion 11 of the case is distributed so as to rapidly rise at the
opposite side to the cover inserting direction, and resistance
against pressure of intrusion of water from the external is
increased.
[0098] Further, in accordance with the sixth embodiment, in the
case that the width w, the height h, the collapsing margin .delta.
and the like of the packing 3 shown in FIG. 25 are the same as
those of the packing 3 shown in FIG. 18 and described previously,
an amount of compression (compressive reaction force) becomes
further smaller in comparison with the packing 3 in FIG. 18.
Therefore, it is possible to further reduce press-fit resistance at
a time of fitting the cover 2 to the opening portion 11 and
abrasion of the packing 3.
* * * * *