U.S. patent application number 11/602847 was filed with the patent office on 2007-03-22 for hole plugs.
Invention is credited to Toshio Iwahara.
Application Number | 20070062962 11/602847 |
Document ID | / |
Family ID | 35428452 |
Filed Date | 2007-03-22 |
United States Patent
Application |
20070062962 |
Kind Code |
A1 |
Iwahara; Toshio |
March 22, 2007 |
Hole plugs
Abstract
A hole plug for closing a through-hole formed in a compartment
wall may include an attaching portion formed from a synthetic resin
and a cover portion integrated with the attaching portion at a
central portion thereof. The attaching portion can be inserted into
the through-hole so as to engage the inner surface of the
compartment wall. The cover portion has a size and shape that can
enclose the through-hole and has a peripheral edge portion that can
closely contact the outer surface of the compartment wall. The
cover portion has a thickened portion that is formed in the
peripheral edge portion thereof or in a vicinity of the peripheral
edge portion and that can maintain a size and configuration of the
peripheral edge portion when an external force is applied to the
cover portion. The cover portion has a thinned portion that is
formed between the thickened portion and the central portion
integrated with the attaching portion and that can undergo elastic
buckling deformation when an external force is applied thereto.
Inventors: |
Iwahara; Toshio;
(Okazaki-shi, JP) |
Correspondence
Address: |
SILBER & FRIDMAN
Suite 207
1037 Route 46 East
Clifton
NJ
07013
US
|
Family ID: |
35428452 |
Appl. No.: |
11/602847 |
Filed: |
November 21, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/JP05/09149 |
May 19, 2005 |
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11602847 |
Nov 21, 2006 |
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Current U.S.
Class: |
220/796 ;
439/798 |
Current CPC
Class: |
B62D 25/24 20130101;
B60R 13/0846 20130101; B60R 13/06 20130101 |
Class at
Publication: |
220/796 ;
439/798 |
International
Class: |
B65D 43/08 20060101
B65D043/08 |
Foreign Application Data
Date |
Code |
Application Number |
May 24, 2004 |
JP |
2004-153438 |
Claims
1. A hole plug for closing a through-hole formed in a compartment
wall, comprising: an attaching portion formed from a synthetic
resin, the attaching portion can be inserted into the through-hole
so as to engage one surface of the compartment wall; and a cover
portion integrated with the attaching portion at a central portion
thereof, the cover portion having a size and shape that can enclose
the through-hole and having a peripheral edge portion that can
closely contact the other surface of the compartment wall, wherein
the cover portion has a configuration maintaining means that is
formed in the peripheral edge portion thereof or in a vicinity of
the peripheral edge portion and that can maintain a size and
configuration of the peripheral edge portion when an external force
is applied to the cover portion, and wherein the cover portion has
an elastic force imparting means that is formed between the
configuration maintaining means and the central portion integrated
with the attaching portion and that can undergo elastic buckling
deformation when the external force is applied thereto, the
peripheral edge portion of the cover portion being capable to
closely contact the other surface of the compartment wall by means
of the elastic force imparting means.
2. The hole plug according to claim 1, wherein the cover portion is
formed of elastomer, and wherein a portion formed with the
configuration maintaining means has a thickness greater than a
portion formed with the elastic force imparting means.
3. A hole plug according to claim 2, wherein the thickened portion
formed of elastomer and formed with the configuration maintaining
means has a double seal structure having a V-shaped cross-sectional
configuration.
Description
[0001] This is a continuation of International Patent Application
PCT/JP2005/009149, filed May 19, 2005, which claims priority of
Japanese Patent Application S.N. 2004-153438, filed May 24,
2004.
FIELD OF THE INVENTION
[0002] The present invention relates to hole plugs. More
specifically, the present invention relates to hole plugs for
sealing through-holes that are formed in various portions of a
structure of a vehicle such as an automobile and which
through-holes are otherwise left open without being used.
BACKGROUND OF THE INVENTION
[0003] A hole plug of this type is inserted into a through-hole,
which is formed in a portion (e.g., a compartment wall) of a
vehicle body or the like at the time of the production thereof and
is otherwise left open without being used, to thereby seal the
through-hole. Therefore, when the hole plug is to be applied to a
through-hole formed in a portion (e.g., an inner panel) of a door
that separates a vehicle interior from a vehicle exterior, the hole
plug has to be designed so as to have a desired sealing performance
such that rainwater, dust or other such material is prevented from
entering the vehicle interior through the through-hole.
[0004] The structure of the hole plug will be described
hereinafter. The hole plug has a cylindrical attaching portion that
is constructed to be fitted into a circular through-hole, and a
dish-shaped cover portion integrally formed at a base portion of
the attaching portion. In such a hole plug, the attaching portion
and the cover portion can be integrally formed from an elastomer
which has a superior elasticity and sealing property. Alternately,
the attaching portion and the cover portion can be separately
formed and then integrated with each other by bonding. In such a
case, the attaching portion and the cover portion can respectively
be formed from a synthetic resin and an elastomer. These examples
of the hole plug will be briefly described below.
[0005] First, in the former type of hole plug, which is integrally
formed from an elastomer, a forward end portion of the attaching
portion is formed in a truncated umbrella-shape so as to protrude
outwardly. More specifically, it is formed so as to have a diameter
greater than the diameter of the through-hole. Conversely, the
cover portion is formed as a truncated reverse umbrella-shape
opposite to the umbrella-shape of the attaching portion. Therefore,
when the truncated umbrella-shaped forward end portion of the
attaching portion is forced into the through-hole in use, the
portion of the attaching portion is inserted thereinto while being
squeezed and narrowed. The forward end portion of the attaching
portion is outwardly restored or spread after passing through the
through-hole, and engages the inner surface of the panel around the
periphery of the through-hole. Also, depending upon the inserting
operation of the attaching portion, the reverse umbrella-shaped
cover portion is forced onto the outer surface of the panel and is
spread thereon. The spread reverse umbrella-shaped cover portion
exerts an adhesion force on the outer surface of the panel around
the periphery of the through-hole. This is because an elastic force
(a repulsive force) is generated due to the engagement of the
attaching portion and the inner surface of the panel. That is, such
an adhesion force is generated according to the elastic force due
to the mutual action of the umbrella-shaped attaching portion and
the reverse umbrella-shaped cover portion.
[0006] Next, in the latter type of hole plug, a forward end portion
of the attaching portion formed from the synthetic resin has
outwardly projected engagement claws that are formed in the side
surface (the circumferential surface) thereof. The engagement claws
are formed so as to outwardly project beyond the diameter of the
through-hole. Further, because the cover portion has substantially
the same construction as the cover portion of the former type of
hole plug, the description thereof will be omitted. Therefore, when
the hole plug thus constructed is forced into the through-hole, the
engagement claw elastically engages the inner surface of the panel
around the periphery of the through-hole. In this case, the spread
reverse umbrella-shaped cover portion exerts an adhesion force on
the outer surface of the panel around the periphery of the
through-hole due to the elastic force (the repulsive force)
thereof.
[0007] A related technique is taught by Patent Document 1 described
in Japanese Laid-Open Utility Model Publication No. 61-202757.
However, in these conventional devices, when the hole plug is
attached to the panel, often times, the attaching portion cannot be
readily inserted into the through-hole and reliably engage the
panel. Further, in some cases, the hole plug of this type cannot
provide sufficient sealing performance (waterproof property and
dustproof property). Further, when the hole plug is attached, the
diameter of a sealing area of the cover portion may be excessively
increased.
[0008] For example, in the former type of hole plug of the above
described conventional examples (in which the hole plug is
integrally formed of elastomer), the cover portion is formed of
elastomer that has a relatively low rigidity. Therefore, when the
worker inserts the umbrella-shaped portion of the attaching portion
into the through-hole of the panel, the worker cannot have a crisp
actual engagement feeling as to whether the umbrella-shaped portion
is restored in the through-hole (as to whether the portion is
reliably engaged to the panel inner surface). Thus, it is
impossible to crisply feel as to whether the attaching portion has
been completely inserted. As a result, it is necessary to
repeatedly apply an additional force to the attaching portion along
the inserting direction. In some cases, it is necessary to redo the
inserting operation of the attaching portion.
[0009] Also, in the case of the latter type of hole plug, the cover
portion is formed from synthetic resin. Therefore, due to the
rigidity of the synthetic resin, it is possible to have the crisp
actual engagement feeling to some degree when the attaching portion
is inserted into the through-hole. However, in this case, even if
the attaching portion engages the panel inner surface, the
attaching portion does not generate any elastic force (repulsive
force) for bringing the umbrella-shaped cover portion into close
contact with the panel outer surface. As a result, it is necessary,
for example, to provide the umbrella-shaped cover portion with a
double-seal structure or to axially elongate the umbrella-shaped
cover portion so that the umbrella-shaped cover portion may exert
an adhesion force (sealing performance) on the panel outer surface.
However, according to the cover portion thus shaped, when the
attaching portion is inserted into the through-hole, the elastic
force acting on the umbrella-shaped of cover portion (the repulsive
force again an insertion force of the hole plug) increases due to
the structure of the cover portion. Therefore, it is difficult to
insert the attaching portion into the through-hole. In addition, if
the umbrella-shaped cover portion is elongated, an extent of the
cover portion (the diameter of the sealing area of the cover
portion) may be unnecessarily increased when the hole plug is
attached to the panel. Consequently, such a hole plug cannot be
used in a place where there is not a sufficient space for the hole
plug.
[0010] The present invention has been made to solve the above
problems. It is one object of the present invention to provide hole
plugs which can be easily attached with an appropriate crisp actual
engagement feeling without losing the sealing performance thereof
and in which extents of cover portions can be effectively reduced
when the hole plugs are in used.
[0011] The hole plug of the present invention is constructed as
follows. First, according to a first invention, a hole plug for
closing a through-hole formed in a compartment wall includes an
attaching portion formed from a synthetic resin, and a cover
portion integrated with the attaching portion at a central portion
thereof. The attaching portion can be inserted into the
through-hole so as to engage one surface of the compartment wall.
The cover portion has a size and shape that can enclose the
through-hole, and has a peripheral edge portion that can closely
contact the other surface of the compartment wall. The cover
portion has a configuration maintaining means that is formed in the
peripheral edge portion thereof or in a vicinity of the peripheral
edge portion and that can maintain a size and configuration of the
peripheral edge portion when an external force is applied to the
cover portion. The cover portion has an elastic force imparting
means that is formed between the configuration maintaining means
and the central portion integrated with the attaching portion and
can undergo elastic buckling deformation when the external force is
applied thereto. The peripheral edge portion of the cover portion
is capable of closely contacting the other surface of the
compartment wall by means of the elastic force imparting means.
[0012] The configuration maintaining means may be formed such that
a sliding frictional force can be produced between the peripheral
edge portion of the cover portion and the other side surface of the
compartment wall so as to restrict the movement of the cover
portion relative to the compartment wall. Also, the configuration
maintaining means may be formed by appropriately selecting the
shape and the material of the peripheral edge portion or the
portion in the vicinity of the peripheral edge portion such that
the portion may have an increased deformation resistance against a
compression force (an increased hoop stress).
[0013] According to the first embodiment of the invention, when the
compression force is applied to the attaching portion for inserting
the attaching portion into the through-hole, the peripheral edge
portion of the cover portion closely contacts the other surface of
the compartment wall. At this time, the size and configuration of
the peripheral edge portion or the portion in the vicinity of the
peripheral edge portion are maintained by means of the
configuration maintaining means if an external force is applied to
the cover portion. Thus, the portion formed with the configuration
maintaining means is securely positioned so as to closely contact
the other surface. As a result, such a portion is not expanded by
the external force. Conversely, the portion between the
configuration maintaining means and the central portion integrated
with the attaching portion is bent inwardly with respect to the
portion formed with the configuration maintaining means when the
external force is applied thereto. The bending is a result of the
elastic force imparting means while undergoing elastic buckling.
Due to the elastic force caused by this bending, the peripheral
edge portion of the cover portion may closely contact the other
surface of the compartment wall.
[0014] Next, according to a second embodiment of the invention, in
the above-described first invention, the cover portion is formed of
elastomer, and a portion formed with the configuration maintaining
means has a thickness greater than a portion formed with the
elastic force imparting means.
[0015] According to the second embodiment of the invention, the
cover portion is integrally formed of elastomer as a unit. Further,
the portion formed with the configuration maintaining means is
thickened. Therefore, such a portion can increase the deformation
resistance (an increased hoop stress), more so than a portion
formed with the elastic force imparting means. Therefore, the
external force can be easily concentrated to the portion formed
with the elastic force imparting means.
[0016] Next, according to a third embodiment of the invention, in
the above-described second invention, the thickened portion formed
of elastomer and formed with the configuration maintaining means
has a double seal structure having a V-shaped cross-sectional
configuration.
[0017] According to the third embodiment of the invention, the
portion formed with the configuration maintaining means of the
cover portion has the V-shaped configuration in cross section.
Therefore, it is possible to reliably keep a sealing posture with
respect to the other surface (contact surface) of the compartment
wall. Accordingly, the elastic force can stably contact the other
surface. Further, the double seal structure may increase sealing
performance of the cover portion.
[0018] The present invention may provide the following effects.
First, according to the first embodiment of the invention, when the
hole plug is inserted into the through-hole, the peripheral edge
portion of the cover portion is not widened (i.e., is not outwardly
expanded). Therefore, the diameter of a sealing area of the cover
portion can be reduced. Further, as the hole plug is inserted into
the through-hole, the cover portion is deformed while undergoing
elastic buckling. Thus, the force required for inserting the hole
plug may be reduced. Also, due to the change in the elastic force
caused by the elastic buckling, an appropriate crisp actual
engagement feeling can be obtained. As a result, the attaching
operation of the hole plug can be facilitated.
[0019] Next, according to the second embodiment of the invention,
the cover portion can be formed by the integral molding of
elastomer. Therefore, the second invention may have increased
sealing performance in addition to the effect of the first
invention.
[0020] Next, according to the third embodiment of the invention,
due to the elastic repulsive force generated in the cover portion,
the peripheral edge portion of the cover portion may stably contact
the other surface of the compartment wall. Therefore, the sealing
performance can be stabilized.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective view of a hole plug according to a
first embodiment of the present invention.
[0022] FIG. 2 is a cross-sectional view of the hole plug, which
illustrates a condition before the hole plug is inserted into a
through-hole formed in a compartment panel.
[0023] FIG. 3 is a cross-sectional view of the hole plug, which
illustrates a condition after the hole plug is inserted into the
through-hole formed in the compartment panel.
[0024] FIG. 4 is a perspective view of a hole plug according to a
second embodiment of the present invention.
[0025] FIG. 5 is a cross-sectional view of the hole plug, which
illustrates an attached condition.
[0026] FIG. 6 is an enlarged cross-sectional view of the hole plug,
which illustrates waterproof function of the hole plug.
[0027] FIG. 7 is a front view of a hole plug according to a third
embodiment of the present invention.
[0028] FIG. 8 is a plan view of FIG. 7.
[0029] FIG. 9 is a right-hand side view of FIG. 7.
[0030] FIG. 10 is a cross-sectional view taken along line A-A of
FIG. 7.
[0031] FIG. 11 is a cross-sectional view taken along line B-B of
FIG. 7.
[0032] FIG. 12 is a cross-sectional view of the hole plug that is
in use.
DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
[0033] Detailed representative embodiments of the present invention
are described with reference to the drawings. FIGS. 1 to 3 show a
hole plug 10 according to a first embodiment of the present
invention. FIG. 1 is a perspective view of the hole plug 10. FIG. 2
is a cross-sectional view of the hole plug 10, which illustrates a
condition before the hole plug 10 is inserted into a through-hole
41 formed in a compartment wall or panel 40. FIG. 3 is a
cross-sectional view of the hole plug 10, which illustrates a
condition after the hole plug 10 is inserted into the through-hole
41 formed in the compartment panel 40. Further, in FIGS. 2 and 3,
references I and O respectively indicate inner and outer sides of
the compartment panel 40.
[0034] It is noted that an example of the compartment panel 40 is a
door panel of a vehicle. Also, the through-hole 41 corresponds to
one of the through-holes that are formed in the compartment panel
40 at the time of the production thereof and the through-hole is
otherwise left open without being used. The hole plug 10 is
intended to be inserted into the through-hole 41 so as to seal the
through-hole 41.
[0035] As best shown in FIG. 1, the hole plug 10 is composed of an
attaching portion 30 formed from a synthetic resin as a bottomed
cylindrical member, and a cover portion 20 integrated with a base
30b of the attaching portion 30 and having a
truncated-umbrella-shape.
[0036] More specifically, as best shown in FIGS. 1 and 2, the
bottomed cylindrically-shaped attaching portion 30 is opened at an
upper or forward end 30a. The base 30b of the attaching portion 30
is closed and is integrated with the cover portion 20. Further, a
cylindrical body portion 31 of the attaching portion 30 is
circumferentially formed with outwardly projecting engagement claws
32 adjacent to the forward end 30a. Further, the engagement claws
32 are formed by forming cutout portions or slots in the
cylindrical body portion 31. More specifically, the engagement
claws 32 are formed so as to protrude beyond the diameter of the
through-hole 41 of the compartment panel 40.
[0037] Thus, when the attaching portion 30 of the hole plug 10 is
forced through the through-hole 41 from the forward end 30a (so as
to be inserted thereinto toward the inner side I of the compartment
panel 40), the attaching portion 30 is elastically narrowed as a
result of the engagement claws 32 abutting a circumferential wall
surface 42 of the through-hole 41 of the compartment panel 40.
Then, as best shown in FIG. 3, when the attaching portion 30 is
further inserted so that the engagement claws 32 pass through the
through-hole 41 and completely reach the inner side I, the
engagement claws 32 are elastically restored or expanded so as to
engage an inner surface 43 of the panel 40. Thus, the attaching
portion 30 is coupled to the through-hole 41 so as be in an
engagement condition (a locking condition) in which it is prevented
from being detached therefrom. It is noted that the inner surface
43 corresponds to one surface in the claimed invention.
[0038] Next, the cover portion 20 is formed from an elastomer which
may be a material having a superior elasticity and sealing
property. As best shown in FIGS. 1 and 2, the cover portion 20 has
a truncated umbrella-shaped peripheral edge portion 21 that
radially extends from a central portion 22 of the cover portion 20.
The cover portion 20 has a size and configuration that can enclose
the through-hole 41. Further, the central portion 22 is integrally
bonded to the base 30b of the attaching portion 30.
[0039] More specifically, the peripheral edge portion 21 of the
cover portion 20 includes a thickened portion 21a which has a
thickness greater than the thickness of an umbrella-shaped side
portion 23. It is noted that the thickened portion 21a corresponds
to a configuration maintaining means of the claimed invention.
Because the peripheral edge portion 21 of the cover portion 20 is
thicker than the side portion 23, when the attaching portion 30 is
inserted into the through-hole 41 (so that a compressive force, or
an external force, is exerted on the cover portion 20), the hoop
stress acting on the peripheral edge portion 21 (thickened portion
21a) is increased. Therefore, even if the cover portion 20 is
applied with the external force, the configuration of the
peripheral edge portion 21 is maintained.
[0040] Further, the thickened portion 21a of the peripheral edge
portion 21 is formed with a seal portion 21b having a V-shaped
cross-sectional configuration. More specifically, as best shown in
FIGS. 2 and 3, when the external force is applied in order to
insert the attaching portion 30 into the through-hole 41, the seal
portion 21b comes into contact with an outer surface 44 of the
compartment panel 40, thereby exerting an adhesion force thereto.
More specifically, the V-shaped contact portion generates a
sustaining force so as to keep a desired sealing posture of the
cover portion 20 when the external force is exerted thereto.
Further, a double-sealing structure is formed so that the sealing
performance can be increased. This is because the contact portion
of the seal portion 21b has a V-shaped cross section so that the
sealing performance can be effectively performed. It is noted that
the outer side surface 44 corresponds to the other surface in the
claimed invention.
[0041] Conversely, the side portion 23 of the cover portion 20 is
formed with a thinned portion 23a that has a thickness thinner than
the thickness of the peripheral edge portion 21. In other words,
when the above-mentioned external force is exerted on the cover
portion 20, the thinned portion 23a can more easily deform than the
thickened portion 21a of the peripheral edge portion 21. Therefore,
this external force is concentrated on the side portion 23 rather
than the peripheral edge portion 21 such that the side portion 23
can be greatly deformed. It is noted that the thinned portion 23a
corresponds to an elastic force imparting means in the claimed
invention.
[0042] Next, a function of the attaching portion 30 and the cover
portion 20 during an attaching operation of the hole plug 10 will
be specifically described with reference to FIGS. 2 and 3.
[0043] First, as best shown in FIG. 2, when an external force in
order to insert the attaching portion 30 into the through-hole 41
is applied, the peripheral edge portion 21 of the cover portion 20
closely contacts the outer side surface 44 of the compartment panel
40. More specifically, the seal portion 21b formed in the
peripheral edge portion 21 and having a V-shaped cross section
closely contacts the outer side surface 44, thereby forming a
double seal. At this time, if the external force is further applied
to the cover portion 20, the size and configuration of the
peripheral edge portion 21 can be maintained due to the thickened
portion 21a. Therefore, the peripheral edge portion 21 can be
securely seated or positioned at the location where the peripheral
edge portion 21 originally contacts the outer surface 44 of the
compartment panel 40. Thus, the cover portion 20 can be prevented
from expanding along the outer surface 44.
[0044] Consequently, this external force is concentrated on the
side portion 23 of the cover portion 20. More specifically, as best
shown in FIG. 3, the side portion 23 is thinner and longer than the
peripheral edge portion 21. Therefore, when the external force is
applied to the positioned peripheral edge portion 21 from an offset
position, the side portion 23 receives a large bending force. As a
result, the side portion 23 is bent inwardly while undergoing local
elastic buckling. Thus, due to this elastic buckling, the force
required for inserting the hole plug 10 is reduced.
[0045] Further, at this time, the side portion 23 is applied with
an elastic force (a restoring force) corresponding to the elastic
deformation due to the bending thereof. This elastic force acts
such that the peripheral edge portion 21 of the cover portion 20 is
brought into close contact with the outer side surface 44 of the
compartment panel 40. Further, due to this elastic force, the seal
portion 21b, having a V-shaped cross-sectional configuration and
formed on the cover portion 20, provides a resisting force against
a force that causes the peripheral edge portion 21 to move along
the outer surface 44.
[0046] Then, when the engagement claw 32 passes through the
through-hole 41 and is elastically expanded the attaching portion
30 engages the inner surface 43 so as to exert an engagement force
that acts against the above-mentioned elastic force. Thus, the
peripheral edge portion 21 of the cover portion 20 is held in a
condition in which it closely contacts the outer surface 44 of the
compartment panel 40.
[0047] Subsequently, a method of using the hole plug 10 of this
embodiment will be described with reference to FIGS. 2 and 3.
First, the attaching portion 30 of the hole plug 10 is forced into
the through-hole 41 from the forward end 30a so as to be inserted
toward the inner side I. As a result, as best shown in FIG. 2, the
peripheral edge portion 21 of the cover portion 20 is brought into
close contact with the outer surface 44 of the compartment panel
40. Thereafter, when the attaching portion 30 is further pressed
toward the inner side I, the peripheral edge portion 21 of the
cover portion 20 is securely positioned on the outer surface 44
without being expanded along the outer surface 44, and the side
portion 23 is bent inwardly while undergoing elastic buckling. That
is, the elastic force (the repulsive force) acting on the cover
portion 20 is reduced. At this time, a worker attaching the hole
plug 10 can feel this change in the elastic force (the repulsive
force) as a desired crisp actual engagement feeling. Therefore,
when the attaching portion 30 is inserted until it engages the
inner surface 43 of the compartment panel 40, the hole plug 10 is
fitted into the through-hole 41 so that the inner side I is brought
into a sealing condition.
[0048] When the hole plug 10 of this embodiment is inserted into
the through-hole 41, the peripheral edge portion 21 of the cover
portion 20 is maintained at a desired position, so that the
diameter of a sealing area of the cover portion 20 can be reduced.
Further, as the hole plug 10 is inserted into the through-hole 41,
the cover portion 20 is deformed while undergoing elastic buckling.
Therefore, the force required for inserting the hole plug 10 may be
reduced. Also, due to the change in the elastic force caused by the
elastic buckling, an appropriate or actual crisp feeling of
engagement can be obtained. As a result, the attaching operation of
the hole plug 10 can be facilitated.
[0049] Further, the cover portion 20 is integrally formed from the
elastomer and has a thickened peripheral edge portion 21 and a
thinned side portion 23. The above-mentioned effect can be obtained
by simple construction described above. Moreover, due to the seal
portion 21b being formed in the cover portion 20 and having a
V-shaped cross-sectional configuration, the adhesion contact force
can be stably exerted on the outer surface 44 of the compartment
panel 40. As a result, sealing performance can be stably
generated.
[0050] A second detailed representative embodiment of the present
invention is described with reference to FIGS. 4 and 5. FIG. 4 is a
perspective view of a hole plug 110. FIG. 5 is a cross-sectional
view of the hole plug 110, which illustrates a condition after the
hole plug 110 is attached.
[0051] As shown in FIGS. 4 and 5, the body member 130 is formed as
a plate-shaped member. In this embodiment, the hole 132 is formed
as a round hole. An example of the body member 130 is an outer
plate of an automobile. Further, the hole 132 formed in this outer
plate is one of the holes that is intended for use as flow holes
for coating material during coating operations and as operation
holes for mounting components. Such a hole 132 is required when the
automobile is manufactured. However, once the manufacturing
operation of the automobile is completed, the hole 132 provides no
further function at all and thus is unnecessary. Generally, the
hole 132 is closed after it becomes unnecessary. The hole plug 110
is intended to be inserted into the hole 132 so as to close the
hole 132. The hole plug 110 may have a waterproof function in order
to intercept the passage of water between interior and exterior
sides of the body member 130.
[0052] The hole plug 110 is composed of a fitting portion 120 and a
blocking portion 125. As seen in FIG. 5, the blocking portion 125
is attached to an upper end of the fitting portion 120. The fitting
portion 120 and the blocking portion 125 are formed as an integral
unit by the molding of a rigid synthetic resin. The fitting portion
120 is a cylindrical portion that is fitted into the hole 132
formed in the body member 130. As seen in the drawing, a desired
number (e.g., four in this example) of engagement claws 121 are
formed at the lower end of the fitting portion 120. In this
embodiment, the four engagement claws 121 are circumferentially
positioned at 90 degree intervals. However, any number of
engagement claws may be formed so as to be circumferentially
positioned over the entire periphery of the fitting portion 120, if
necessary.
[0053] As shown in FIG. 4, the engagement claws 121 are formed by
forming cutout portions or slots 126 in the fitting portion 120.
Therefore, the engagement claws 121 can be independently radially
flexed. More specifically, the engagement claws 121 are radially
outwardly biased. Therefore, the engagement claws 121 engage the
lower edge of the hole 132 of the body member 130, thereby
preventing upward detachment of the fitting portion 120, as seen in
FIG. 5.
[0054] The blocking portion 125 is the portion for blocking the
hole 132 formed in the body member 130 and is formed as a
disc-shaped member having an area larger than that of the hole 132.
As shown in the drawing, the lower surface of the blocking portion
125 is formed with a central protrusion 140 and a circumferential
seal member 111. Also, the upper end of the fitting portion 120 is
integrally attached to the lower surface of the blocking portion
125 at a middle portion between the protrusion 140 and the seal
member 111. The protrusion 140 is inherently formed when the
blocking portion 125 is formed by the resin molding. The length of
the protrusion 140 is smaller than that of the fitting portion
120.
[0055] The seal member 111 is composed of two annular seal strips
111a and 111b that are continuously formed. The seal strip 111a is
circumferentially outwardly positioned, and the seal strip 111b is
circumferentially inwardly positioned. The seal strips 111a and
111b are integrated at their base portions and are securely
attached to the block portion 125 by an appropriate fixing means
such as adhesion.
[0056] The outwardly positioned seal strip 111a is arranged so as
to be radially outwardly directed and to be downwardly inclined
toward the body member 130, and is positioned so as to have an
appropriate pressing contact with the surface of the body member
130. To the contrary, the inwardly positioned seal strip 111b is
arranged so as to be radially inwardly directed and to be
downwardly inclined toward the body member 130, and is positioned
so as to have an appropriate pressing contact with the surface of
the body member 130. That is, the seal strips 111a and 111b are
arranged so as to be radially oppositely directed.
[0057] The seal strips 111a and 111b constituting the seal member
111 are formed of a material that can provide a sealing function.
For example, they may be formed of a rubber material or a resin
material such as an elastomer.
[0058] Next, the sealing function of the hole plug 110 of this
embodiment constructed as described above will be described with
reference to FIG. 6. FIG. 6 is an enlarged view of the left-hand
side of FIG. 5, which illustrates a cross-sectional view of the
hole plug 110.
[0059] First, with regard to water that enters from the outer side
of the body member 130 toward the inner side (i.e., from the upper
side toward the lower side as seen in the drawing). For water that
enters in a direction indicated shown by the arrows (a) a sealing
function and waterproof function can be performed by means of the
outwardly positioned seal strip 111a of the seal member 111. That
is, when the water enters in the direction shown by the arrows (a),
the water pressure of the water may act on the outer surface of the
seal strip 111a so that the pressing contact force between the seal
strip 1a and the body member 130 can be increased. As a result, the
water entering in the direction shown by the arrows (a) can be
prevented by the seal strip 111a so that the hole plug 110 may
provide a sufficient waterproof function.
[0060] Next, with regard to water that enters from the inner side
of the body member 130 toward the outer side (i.e., from the lower
side toward the upper side as seen in the drawing). For water that
enters in a reverse direction indicated shown by the arrows (b) a
sealing function and waterproof function can be performed by means
of the inwardly positioned seal strip 111b of the seal member 111.
That is, when the water enters in the direction shown by the arrows
(b), the water pressure of the water may act on the outer surface
of the seal strip 111b so that the pressing contact force between
the seal strip 111b and the body member 130 can be increased. As a
result, the water entering in the direction shown by the arrows (b)
can also be prevented by the seal strip 111b so that the hole plug
110 may provide a sufficient waterproof function.
[0061] That is, according to the hole plug 110 of this embodiment,
a waterproof function is provided with respect to water that enters
in both directions indicated by the arrows (a) and (b), i.e., water
that enters from each of the inner and outer sides of the body
member 130.
[0062] In this embodiment, as in the prior art, the engagement
claws 121 of the fitting portion 120 unremovably engage the hole
132. Therefore, a pressing contact force is generated between the
seal strips 111a and 111b and the surface of the body member 130,
thereby producing a sealing function. As a result, more
specifically, the waterproof function of the seal member 111 is a
combination of these two seal functions.
[0063] In this way, according to the hole plug 110 of this
embodiment, which is attached by fitting the hole plug 110 into the
hole 132 formed in the body member 130, the seal member 111 can
prevent water from entering through the hole 132 from both of the
outer and inner sides of the body member 130. Therefore, the seal
member 111 can effectively provide a two-way waterproofing
function.
[0064] Further, the seal member is composed of the two seal
members. One of the seal strips can prevent water from entering
from one side to the other side of the body member 130. Conversely,
the other of the seal strips can reliably prevent water from
entering from the other side to one side of the body member 130. As
a result, the two seal members can effectively provide a waterproof
function that can prevent water from entering from both sides.
[0065] Further, when the hole plug 110 is attached to the body
member 130, it is possible to prevent water intrusion regardless of
whether the hole plug is attached from the exterior or the interior
of the vehicle. Therefore, there is no need to observe the
attaching direction of the hole plug 110. As a result, workability
for attaching the hole plug can be increased.
[0066] A third detailed representative embodiment of the present
invention is described with reference to the drawings. FIG. 7 is a
front view of a hole plug. FIG. 8 is a plan view of FIG. 7. FIG. 9
is a right-hand side view of FIG. 7. FIG. 10 is a cross-sectional
view taken along line A-A of FIG. 7. FIG. 11 is a cross-sectional
view taken along line B-B of FIG. 7.
[0067] As will be apparent from these drawings, the hole plug is
composed of a seal portion 210 and a fitting portion 220. The seal
portion 210 has a circular disc-shaped configuration. The fitting
portion 220 has a cylindrical configuration that corresponds to the
configuration of a through-hole 232 formed in a body member 230
described below.
[0068] The seal member 210 is formed by covering a core member 212
with a covering material 214. The core member 212 is formed from a
rigid synthetic resin such as polypropylene (PP). Conversely, the
covering material 214 is formed from a flexible synthetic resin
such as elastomer resin. That is, the seal portion 210 has a
structure in which the entire surface of the rigid core member 212
is covered with a thin flexible covering material 214 (FIGS. 10 and
11). It should be noted that an edge portion 216, i.e., an outer
peripheral edge of the seal portion 210, is formed from only the
flexible covering material 214.
[0069] The fitting portion 220 is integrally formed with the core
member 212. Therefore, the fitting portion 220 is also formed from
the rigid synthetic resin. The outer side portion of the fitting
portion 220 is integrally formed with engagement claws 222 and 226
that are respectively positioned at four positions, i.e., two
positions on the right and left and two positions on the front and
rear in FIG. 7. As will be apparent from FIGS. 8 and 10, the right
and left engagement claws 222 in FIG. 7 protrude outwardly with a
curvature from the end portion of the fitting portion 220. Thus,
the engagement claws 222 have a desired flexibility. The engagement
claws 222 are respectively formed with outwardly projecting
engagement portions 223. The engagement portions 223 are positioned
near the forward ends of the engagement claws 222 and further
protrude outwardly therefrom. Conversely, as will be apparent from
FIG. 11, the front and rear engagement claws 26 in FIG. 7 are
connected to the fitting portion 220 at the end portions thereof.
In other words, the engagement claws 226 are formed by forming
cutout portions or slots in the fitting portion 220. Therefore, the
engagement claws 226 have a desired flexibility. The engagement
claws 226 are also respectively formed with outwardly projecting
engagement portions 227.
[0070] FIG. 12 is a cross-sectional view of the hole plug that is
in use. In this drawing, the through-hole 232 corresponds to one of
the through-holes that are formed in the body member 230 (e.g., a
vehicle body) thereof and is otherwise left open without being
used. The hole plug is intended to be inserted into the
through-hole 232 for waterproofing and dustproofing.
[0071] In order to seal the through-hole 232, the fitting portion
220 of the hole plug is inserted into the through-hole 232 from the
outer surface side of the body member 230. As a result, the
engagement claws 222 and 226 pass through the through-hole 232
while being flexed inwardly so that the respective engagement
portions 223 and 227 engage the peripheral edge of the through-hole
232 on the inner surface of the body member 230.
[0072] The dimension of the fitting portion 220 has a size that
permits it to easily fit into the through-hole 232. Also, the
engagement claws 222 and 226 can easily and independently flex.
Therefore, the fitting portion 220 can be inserted into the
through-hole 232 with a small force. Further, since the engagement
claws 222 and 226 are formed from a rigid synthetic resin, when the
engagement portions 223 and 227 engage the inner surface of the
body member 230 as described above, an actual crisp feeling of
engagement can be obtained. In addition, the hole plug can be
reliably attached to the body member 230 with a sufficient
retaining force.
[0073] Although, the right and left engagement claws 222 and the
front and rear engagement claws 226 in FIG. 7 are different from
each other, such a difference in shape is not essential in
function. Therefore, it is naturally possible to unify the shape of
the engagement claws 222 and 226 to either of the individual
shapes.
[0074] In a condition in which the fitting portion 220 has been
thus fitted into the through-hole 232, the seal portion 210 of the
hole plug is being pressed against the outer surface of the body
member 230 around the through-hole 232. In particular, because the
edge portion 216 of the seal portion 210 is formed from only the
soft covering material 214, the edge portion 216 has good adhesion
with the outer surface of the body member 230. Therefore, the hole
plug may have good waterproof and dustproof performances. Further,
although the edge portion 216 is formed from only the covering
material 214, it is possible to form the edge portion 216 from the
core member 212 and the covering material 214, and to design the
hole plug such that the covering material 214 of the edge portion
216 has a thickness greater than the covering material 214 of the
main portion.
[0075] As shown in FIGS. 10 and 11, the covering material 214 is
only provided to the portion in which waterproof or dustproof
function is required. The hole plug of this embodiment is, for
example, formed by filling a molding die with a flexible synthetic
resin (the covering material 214), and then filling the molding die
with a rigid synthetic resin (the core material 212). In this
forming method, it may be impossible to define the boundary between
the portion of the core member 212 that is covered with the
covering material 214 and the portion thereof that is not covered
with the covering material 214. However, this boundary is not a
very important factor. What is important is that the core member
212 is covered by the covering material 214 at least in the seal
portion 210. Further, the fitting portion 220 and the engagement
claws 222 and 226 may optionally be covered with the covering
material 214.
[0076] Various changes and modifications may be made to the three
embodiments described above. Initially, in the first embodiment,
the thickened portion 21a is formed at the peripheral edge portion
21 of the cover portion 20. However, the thickened portion can be
formed in the vicinity of the peripheral edge portion in
consideration of particular design properties. In this case also,
it is possible to maintain the size and configuration of the
peripheral edge portion.
[0077] Further, the side portion 23 of the cover portion 20 is
formed with the thinned portion 23a as the elastic force imparting
means. However, instead, the side portion of the cover portion may
be partially formed with cutout portions so that concentration of
the external force (stress concentration) can occur. In addition,
it is possible to change the offset position of the thickened
portion that is applied with the external force so that a large
bending stress is exerted on the side portion.
[0078] Further, in the first embodiment, the through-hole 41 has a
circular shape, and the hole plug 10 is shaped so as to correspond
to the shape of the through-hole. However, the through-hole may
have a rectangular or triangular shape. Naturally, in such a case,
the shape of the attaching portion and the cover portion is
modified so as to correspond to the shape of the through-hole.
[0079] Moreover, in the second embodiment, the hole 132 formed in
the body member 130 has a circular shape. However, the hole 132 may
have a rectangular shape. Similarly, the seal members 111a and 111b
of the seal member 111 have a circular shape. Naturally, the seal
members 111a and 111b can be modified so as to correspond to the
shape of the hole 132. Further, it should be noted that the seal
members must be continuously formed regardless of the shape
thereof.
* * * * *