U.S. patent application number 09/960331 was filed with the patent office on 2002-03-28 for connection structure and valved connection member.
This patent application is currently assigned to TOKAI RUBBER INDUSTRIES, LTD.. Invention is credited to Ito, Tomohide, Miyajima, Atsuo.
Application Number | 20020036015 09/960331 |
Document ID | / |
Family ID | 26600636 |
Filed Date | 2002-03-28 |
United States Patent
Application |
20020036015 |
Kind Code |
A1 |
Miyajima, Atsuo ; et
al. |
March 28, 2002 |
Connection structure and valved connection member
Abstract
A connection member includes a nipple portion formed at one end
and a first end face portion formed at an end part of the nipple
portion. A valve cap includes a small-diameter portion; a
large-diameter portion; a valve seat portion having a valve seal
surface formed on an inner circumferential surface of the valve cap
and located between the small-diameter portion and the
large-diameter portion; and a fitting end portion fitted to the
outer circumferential surface of the end part of the nipple
portion. A valve body includes a bottom portion having an abutment
part to abut the valve seal surface; a cylindrical open end portion
extending from the bottom portion; a second end face portion formed
at the open end portion in such a manner as to face the first end
face portion; a first sliding portion provided on the open end
portion; and a first flow path portion provided in the first
sliding portion. The valve body is accommodated within the
large-diameter portion in an axially slidable condition. A
compression spring is disposed between the first end face portion
and the second end face portion and adapted to bias the valve body
toward the valve seat portion of the valve cap. One end portion of
a flexible tube is fitted to the outer circumferential surface of
the valve cap and the outer circumferential surface of the nipple
portion.
Inventors: |
Miyajima, Atsuo;
(Inuyama-shi, JP) ; Ito, Tomohide; (Kasugai-shi,
JP) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
TOKAI RUBBER INDUSTRIES,
LTD.
Komaki-shi
JP
|
Family ID: |
26600636 |
Appl. No.: |
09/960331 |
Filed: |
September 24, 2001 |
Current U.S.
Class: |
137/543.23 |
Current CPC
Class: |
F16L 33/30 20130101;
F02M 25/0872 20130101; Y10T 137/7939 20150401; F16K 15/026
20130101 |
Class at
Publication: |
137/543.23 |
International
Class: |
F16K 015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2000 |
JP |
2000-290172 |
Aug 3, 2001 |
JP |
2001-237012 |
Claims
What is claimed is:
1. A connection structure comprising a valved connection member and
a flexible tube connected to said valved connection member, said
valved connection member comprising: a cylindrical connection
member comprising a cylindrical nipple portion formed at one end
and allowing an inner circumferential surface of an end portion of
said flexible tube to be fitted thereto; and an annular first end
face portion formed at an end part of the nipple portion in such a
manner as to face toward the one end and to extend radially; a
cylindrical valve cap comprising a small-diameter portion and a
large-diameter portion, an axial bore formed in the small-diameter
portion being smaller in diameter than an axial bore formed in the
large-diameter portion; a valve seat portion having a valve seal
surface formed on an inner circumferential surface of said
cylindrical valve cap and located between the small-diameter
portion and the large-diameter portion; and a fitting end portion
formed at one end of the large-diameter portion away from the
small-diameter portion and fitted to an outer circumferential
surface of the end part of the nipple portion of said connection
member; a cylindrical valve body comprising a bottom portion having
an abutment part to abut the valve seal surface of said valve cap;
a cylindrical open end portion extending from the bottom portion
and opening toward the connection member; an annular second end
face portion formed at the open end portion in such a manner as to
face the first end face portion and to extend radially; a first
sliding portion extending radially outward from the open end
portion in an integral condition; and a first flow path portion
provided in the first sliding portion and allowing flow of fluid;
said valve body being accommodated within the large-diameter
portion of said valve cap in such a manner as to be axially
slidable by virtue of the first sliding portion; and a compression
spring disposed between the first end face portion and the second
end face portion and adapted to bias said valve body toward the
valve seat portion of said valve cap; one end portion of said
flexible tube being fitted to an outer circumferential surface of
said valve cap fitted to the outer circumferential surface of the
end part of the nipple portion of said connection member as well as
being fitted to an outer circumferential surface of the nipple
portion extending away from the outer circumferential surface of
said valve cap.
2. A connection structure according to claim 1, wherein said valve
body further comprises a second sliding portion extending from the
bottom portion away from the open end portion and accommodated
slidably within the small-diameter portion of said valve cap; and a
second flow path portion formed in the second sliding portion and
allowing flow of fluid.
3. A connection structure according to claim 1 or 2, wherein a flow
adjustment bore is axially formed in the bottom portion of said
valve body in such a manner as to extend through the bottom
portion.
4. A connection structure comprising a valved connection member and
a flexible tube connected to said valved connection member, said
valved connection member comprising: a cylindrical connection
member comprising a cylindrical nipple portion formed at one end
and allowing an inner circumferential surface of an end portion of
said flexible tube to be fitted thereto; and an annular first end
face portion formed at an end part of the nipple portion in such a
manner as to face toward the one end and to extend radially; a
cylindrical valve cap comprising a small-diameter portion and a
large-diameter portion, an axial bore formed in the small-diameter
portion being smaller in diameter than an axial bore formed in the
large-diameter portion; a valve seat portion having a valve seal
surface formed on an inner circumferential surface of said
cylindrical valve cap and located between the small-diameter
portion and the large-diameter portion; a first sliding portion
extending radially inward from an inner circumferential surface of
the large-diameter portion in an integral condition and located in
the vicinity of a boundary between the small-diameter portion and
the large-diameter portion; a first flow path portion formed in the
first sliding portion and allowing flow of fluid; and a fitting end
portion formed at one end of the large-diameter portion away from
the small-diameter portion and fitted to an outer circumferential
surface of the end part of the nipple portion of said connection
member; a cylindrical valve body comprising a bottom portion having
an abutment part to abut the valve seal surface of said valve cap;
a cylindrical open end portion extending from the bottom portion
and opening toward the connection member; and an annular second end
face portion formed at the open end portion in such a manner as to
face the first end face portion and to extend radially; said valve
body being accommodated within the large-diameter portion of said
valve cap in such a manner as to be axially slidable by virtue of
the first sliding portion; and a compression spring disposed
between the first end face portion and the second end face portion
and adapted to bias said valve body toward the valve seat portion
of said valve cap; one end portion of said flexible tube being
fitted to an outer circumferential surface of said valve cap fitted
to the outer circumferential surface of the end part of the nipple
portion of said connection member as well as being fitted to an
outer circumferential surface of the nipple portion extending away
from the outer circumferential surface of said valve cap.
5. A connection structure according to claim 4, wherein said valve
body further comprises a second sliding portion extending from the
bottom portion away from the open end portion and accommodated
slidably within the small-diameter portion of said valve cap; and a
second flow path portion formed in the second sliding portion and
allowing flow of fluid.
6. A connection structure according to claim 4 or 5, wherein a flow
adjustment bore is axially formed in the bottom portion of said
valve body in such a manner as to extend through the bottom
portion.
7. A connection structure comprising a valved connection member and
a flexible tube connected to said valved connection member, said
valved connection member comprising: a cylindrical connection
member comprising a cylindrical nipple portion formed at one end
and allowing an inner circumferential surface of an end portion of
said flexible tube to be fitted thereto; and an annular first end
face portion formed at an end part of the nipple portion in such a
manner as to face toward the one end and to extend radially; a
cylindrical valve cap comprising a small-diameter portion and a
large-diameter portion, an axial bore formed in the small-diameter
portion being smaller in diameter than an axial bore formed in the
large-diameter portion; a valve seat portion having a valve seal
surface formed on an inner circumferential surface of said
cylindrical valve cap and located between the small-diameter
portion and the large-diameter portion; and a fitting end portion
formed at one end of the large-diameter portion away from the
small-diameter portion and fitted to an outer circumferential
surface of the end part of the nipple portion of said connection
member; a cylindrical valve body comprising a bottom portion having
an abutment part to abut the valve seal surface of said valve cap;
a cylindrical open end portion extending from the bottom portion
and opening toward the connection member; an annular second end
face portion formed at the open end portion in such a manner as to
face the first end face portion and to extend radially; a sliding
portion extending integrally from the bottom portion away from the
open end portion; and a flow path portion provided in the sliding
portion and allowing flow of fluid; said valve body being
accommodated within said valve cap in such a manner as to be
axially slidable by virtue of the sliding portion; and a
compression spring disposed between the first end face portion and
the second end face portion and adapted to bias said valve body
toward the valve seat portion of said valve cap; one end portion of
said flexible tube being fitted to an outer circumferential surface
of said valve cap fitted to the outer circumferential surface of
the end part of the nipple portion of said connection member as
well as being fitted to an outer circumferential surface of the
nipple portion extending away from the outer circumferential
surface of said valve cap.
8. A connection structure according to claim 7, wherein a flow
adjustment bore is axially formed in the bottom portion of said
valve body in such a manner as to extend through the bottom
portion.
9. A valved connection member to be connected with a flexible tube,
comprising: a cylindrical connection member comprising a
cylindrical nipple portion formed at one end and allowing an inner
circumferential surface of an end portion of the flexible tube to
be fitted thereto; a cylindrical valve cap comprising a
small-diameter portion and a large-diameter portion, a valve seal
surface being formed on an inner circumferential surface of said
cylindrical valve cap and located between the small-diameter
portion and the large-diameter portion, said cylindrical valve cap
being fitted to an end part of the nipple portion of said
connection member with the large-diameter portion facing said
connection member; a valve body comprising a bottom portion having
an abutment part to abut the valve seal surface of said valve cap,
said valve body being accommodated within the large-diameter
portion of said valve cap in such a manner as to be axially
slidable; and a compression spring disposed between the
large-diameter portion of said valve cap and the nipple portion of
said connection member and adapted to bias said valve body toward
the valve seal surface of said valve cap.
10. A valved connection member according to claim 9, wherein said
valve body comprises a sliding portion extending from the bottom
portion away from the large-diameter portion of said valve cap and
accommodated slidably within the small-diameter portion of said
valve body; and a flow path portion provided in the sliding portion
and allowing flow of fluid.
11. A valved connection member according to claim 9 or 10, wherein
a flow adjustment bore is axially formed in the bottom portion of
said valve body in such a manner as to extend through the bottom
portion.
12. A valved connection member to be connected with a flexible
tube, comprising: a cylindrical connection member comprising a
cylindrical nipple portion formed at one end and allowing an inner
circumferential surface of an end portion of said flexible tube to
be fitted thereto; and an annular first end face portion formed at
an end part of the nipple portion in such a manner as to face
toward the one end and to extend radially; a cylindrical valve cap
comprising a small-diameter portion and a large-diameter portion,
an axial bore formed in the small-diameter portion being smaller in
diameter than an axial bore formed in the large-diameter portion; a
valve seat portion having a valve seal surface formed on an inner
circumferential surface of said cylindrical valve cap and located
between the small-diameter portion and the large-diameter portion;
and a fitting end portion formed at one end of the large-diameter
portion away from the small-diameter portion and fitted to an outer
circumferential surface of the end part of the nipple portion of
said connection member; a cylindrical valve body comprising a
bottom portion having an abutment part to abut the valve seal
surface of said valve cap; a cylindrical open end portion extending
from the bottom portion and opening toward the connection member;
an annular second end face portion formed at the open end portion
in such a manner as to face the first end face portion and to
extend radially; a first sliding portion extending radially outward
from the open end portion in an integral condition; and a first
flow path portion provided in the first sliding portion and
allowing flow of fluid; said valve body being accommodated within
the large-diameter portion of said valve cap in such a manner as to
be axially slidable by virtue of the first sliding portion; and a
compression spring disposed between the first end face portion and
the second end face portion and adapted to bias said valve body
toward the valve seat portion of said valve cap.
13. A valved connection member according to claim 12, wherein said
valve body further comprises a second sliding portion extending
from the bottom portion away from the open end portion and
accommodated slidably within the small-diameter portion of said
valve cap; and a second flow path portion formed in the second
sliding portion and allowing flow of fluid.
14. A valved connection member according to claim 12 or 13, wherein
a flow adjustment bore is axially formed in the bottom portion of
said valve body in such a manner as to extend through the bottom
portion.
15. A valved connection member to be connected with a flexible
tube, comprising: a cylindrical connection member comprising a
cylindrical nipple portion formed at one end and allowing an inner
circumferential surface of an end portion of the flexible tube to
be fitted thereto; and an annular first end face portion formed at
an end part of the nipple portion in such a manner as to face
toward the one end and to extend radially; a cylindrical valve cap
comprising a small-diameter portion and a large-diameter portion,
an axial bore formed in the small-diameter portion being smaller in
diameter than an axial bore formed in the large-diameter portion; a
valve seat portion having a valve seal surface formed on an inner
circumferential surface of said cylindrical valve cap and located
between the small-diameter portion and the large-diameter portion;
a first sliding portion extending radially inward from an inner
circumferential surface of the large-diameter portion in an
integral condition and located in the vicinity of a boundary
between the small-diameter portion and the large-diameter portion;
a first flow path portion formed in the first sliding portion and
allowing flow of fluid; and a fitting end portion formed at one end
of the large-diameter portion away from the small-diameter portion
and fitted to an outer circumferential surface of the end part of
the nipple portion of said connection member; a cylindrical valve
body comprising a bottom portion having an abutment part to abut
the valve seal surface of said valve cap; a cylindrical open end
portion extending from the bottom portion and opening toward the
connection member; and an annular second end face portion formed at
the open end portion in such a manner as to face the first end face
portion and to extend radially; said valve body being accommodated
within the large-diameter portion of said valve cap in such a
manner as to be axially slidable by virtue of the first sliding
portion; and a compression spring disposed between the first end
face portion and the second end face portion and adapted to bias
said valve body toward the valve seat portion of said valve
cap.
16. A valved connection member according to claim 15, wherein said
valve body further comprises a second sliding portion extending
from the bottom portion away from the open end portion and
accommodated slidably within the small-diameter portion of said
valve cap; and a second flow path portion formed in the second
sliding portion and allowing flow of fluid.
17. A valved connection member according to claim 15 or 16, wherein
a flow adjustment bore is axially formed in the bottom portion of
said valve body in such a manner as to extend through the bottom
portion.
18. A valved connection member to be connected with a flexible
tube, comprising: a cylindrical connection member comprising a
cylindrical nipple portion formed at one end and allowing an inner
circumferential surface of an end portion of said flexible tube to
be fitted thereto; and an annular first end face portion formed at
an end part of the nipple portion in such a manner as to face
toward the one end and to extend radially; a cylindrical valve cap
comprising a small-diameter portion and a large-diameter portion,
an axial bore formed in the small-diameter portion being smaller in
diameter than an axial bore formed in the large-diameter portion; a
valve seat portion having a valve seal surface formed on an inner
circumferential surface of said cylindrical valve cap and located
between the small-diameter portion and the large-diameter portion;
and a fitting end portion formed at one end of the large-diameter
portion away from the small-diameter portion and fitted to an outer
circumferential surface of the end part of the nipple portion of
said connection member; a cylindrical valve body comprising a
bottom portion having an abutment part to abut the valve seal
surface of said valve cap; a cylindrical open end portion extending
from the bottom portion and opening toward the connection member;
an annular second end face portion formed at the open end portion
in such a manner as to face the first end face portion and to
extend radially; a sliding portion extending integrally from the
bottom portion away from the open end portion; and a flow path
portion provided in the sliding portion and allowing flow of fluid;
said valve body being accommodated within said valve cap in such a
manner as to be axially slidable by virtue of the sliding portion;
and a compression spring disposed between the first end face
portion and the second end face portion and adapted to bias said
valve body toward the valve seat portion of said valve cap.
19. A valved connection member according to claim 18, wherein a
flow adjustment bore is axially formed in the bottom portion of
said valve body in such a manner as to extend through the bottom
portion.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a valved connection member
favorably usable in an evaporation piping system of an automobile
fuel tank,etc. and to a connection structure using the valved
connection member.
[0003] 2. Description of the Related Art
[0004] The internal pressure of an automobile fuel tank built up by
evaporated gasoline is controlled through connection of the fuel
tank and a canister located on the engine side by means of piping.
Specifically, a check valve is installed in an evaporation line
connecting the fuel tank and the canister so as to allow flow of
evaporated gasoline from the fuel tank to the engine but not in the
reverse direction.
[0005] Conventionally, the fuel tank and the check valve are
connected by means of a rubber hose, and the check valve and the
canister are also connected by means of a rubber hose. Connections
are each clamped from outside the rubber hose by means of a clamp
member, such as a clip. However, such connection practice involves
an increase in the number of components and very complicated
connection work, resulting in increased cost.
[0006] According to recent tendencies, in order to suppress
permeation of gasoline and to improve connection workability, a
resin tube is used in place of a rubber hose. Resin tubes are used
in the following manner. Resin tubes are connected to corresponding
opposite ends of the check valve, and quick connectors are
connected to the respective free ends of the resin tubes. The quick
connectors are used for connection to the fuel tank and the
canister.
[0007] A conventionally used check valve is configured such that a
valve body is movably disposed within a substantially cylindrical
housing, while being biased toward a valve seat formed at one end
of the housing by means of a valve spring. Accordingly, the
conventional check valve is a separate member from the quick
connector and the rubber hose or resin tube and is press-fitted,
for use, into an end portion of the rubber hose or the resin tube.
Also, assembly of the check valve is complicated in terms of
process and accuracy; for example, welding upper and lower housing
halves is required.
[0008] As mentioned above, since the check valve to be installed
in, for example, an evaporation piping system of an automobile fuel
tank, is a separate member from the quick connector and the rubber
hose or resin tube, the number of components increases and
connection work becomes complicated, resulting in difficulty in
reducing cost.
[0009] In order to meet recent requirements for further reduction
in gasoline permeability, even very small permeation from a
connection between the rubber hose or the resin tube and the check
valve cannot be disregarded. Thus, a reduction in connections
between components is an effective means for suppression permeation
of gasoline.
SUMMARY OF THE INVENTION
[0010] An object of the present invention is to solve the
above-mentioned problems, and to provide a connection member of
simple structure equipped with a check valve allowing a reduction
in the number of components of a piping system, such as an
evaporation piping system, that requires installation of a check
valve, and a reduction in the number of connections, as well as to
provide a connection structure of low gasoline permeability and low
cost favorably usable in, for example, an evaporation piping system
employing a valved connection member.
[0011] To achieve the above object, according to a first aspect of
the present invention, a connection structure comprises a valved
connection member and a flexible tube connected to the valved
connection member. The valved connection member comprises a
cylindrical connection member, a cylindrical valve cap, a
cylindrical valve body, and a compression spring. The cylindrical
connection member comprises a cylindrical nipple portion formed at
one end and allowing the inner circumferential surface of an end
portion of the flexible tube to be fitted thereto; and an annular
first end face portion formed at an end part of the nipple portion
in such a manner as to face toward the one end and to extend
radially. The cylindrical valve cap comprises a small-diameter
portion and a large-diameter portion, an axial bore formed in the
small-diameter portion being smaller in diameter than an axial bore
formed in the large-diameter portion; a valve seat portion having a
valve seal surface formed on the inner circumferential surface of
the cylindrical valve cap and located between the small-diameter
portion and the large-diameter portion; and a fitting end portion
formed at one end of the large-diameter portion away from the
small-diameter portion and fitted to the outer circumferential
surface of the end part of the nipple portion of the connection
member. The cylindrical valve body comprises a bottom portion
having an abutment part to abut the valve seal surface of the valve
cap; a cylindrical open end portion extending from the bottom
portion and opening toward the connection member; an annular second
end face portion formed at the open end portion in such a manner as
to face the first end face portion and to extend radially; a first
sliding portion extending radially outward from the open end
portion in an integral condition; and a first flow path portion
provided in the first sliding portion and allowing flow of fluid.
The valve body is accommodated within the large-diameter portion of
the valve cap in such a manner as to be axially slidable by virtue
of the first sliding portion. The compression spring is disposed
between the first end face portion and the second end face portion
and adapted to bias the valve body toward the valve seal surface.
One end portion of the flexible tube is fitted to the outer
circumferential surface of the valve cap fitted to the outer
circumferential surface of the end part of the nipple portion of
the connection member and is further fitted to the outer
circumferential surface of the nipple portion extending away from
the outer circumferential surface of the valve cap.
[0012] According to the first aspect of the present invention,
since the valve body is biased toward the valve seat portion by
means of the compression spring, the abutment part of the bottom
portion of the valve body is in close contact with the valve seal
surface of the valve cap. Accordingly, when the upstream fluid
pressure of the connection structure is lower than the downstream
fluid pressure, a flow path including the first flow path portion
is closed to thereby disable flow of fluid. In contrast, when the
upstream fluid pressure becomes higher than the downstream fluid
pressure, the valve body moves toward the connection member against
the compression spring. Thus, the abutment part of the bottom
portion of the valve body moves away from the valve seal surface
and toward the connection member, thereby forming a gap between the
abutment part and the valve seal surface. As a result, the flow
path including the first flow path portion is opened to thereby
permit downstream flow of fluid. In this case, the valve body can
smoothly move within the large-diameter portion in the axial
direction by virtue of the first sliding portion. Also, the first
flow path portion provided in the first sliding portion smoothens
flow of fluid.
[0013] Since the connection structure is configured such that the
valve body is accommodated within the valve cap fitted to the
connection member, the number of components as well as the number
of connections can be reduced. Thus, the cost of the connection
structure can be reduced, and assembly work time can be
shortened.
[0014] Even though the valve cap is merely fitted to the outer
circumferential surface of the end part of the nipple portion of
the connection member, since one end portion of the flexible tube
is fitted to the outer circumferential surface of the valve cap
fitted to the connection member and is further fitted to the outer
circumferential surface of the nipple portion extending away from
the outer circumferential surface of the valve cap, the connection
can exhibit low gasoline permeability. Since no welding is required
for connection of the valve cap and the end part of the nipple
portion of the connection member, the cost of connection can be
reduced.
[0015] In the first aspect of the present invention, instead of the
first sliding portion and the first flow path portion being
provided on the open end portion of the valve body, the first
sliding portion and the first flow path can be provided on the
inner circumferential surface of the large-diameter portion of the
valve cap in the vicinity of the boundary between the
large-diameter and small-diameter portions. When the upstream fluid
pressure of the connection structure becomes higher than the
downstream fluid pressure, so that the valve body moves toward the
connection member against the compression spring, the first sliding
portion provided on the valve cap allows smooth axial movement of
the valve body within the large-diameter portion, and the first
flow path portion provided in the first sliding portion allows
smooth flow of fluid.
[0016] The first aspect of the present invention allows the valve
body to further comprise a second sliding portion extending from
the bottom portion away from the open end portion and accommodated
slidably within the small-diameter portion of the valve cap; and a
second flow path portion formed in the second sliding portion and
allowing flow of fluid. The second sliding portion allows further
smooth axial movement of the valve body, and the second flow path
portion allows smooth flow of fluid at the second sliding
portion.
[0017] In the first aspect of the present invention, instead of the
first sliding portion being provided on the open end portion of the
valve body or on the inner circumferential surface of the
large-diameter portion of the valve cap in the vicinity of the
boundary between the large-diameter and small-diameter portions,
the sliding portion can be provided in such a manner as to extend
from the bottom portion away from the open end portion. When the
upstream fluid pressure of the connection structure becomes higher
than the downstream fluid pressure, so that the valve body moves
toward the connection member against the compression spring, the
sliding portion allows smooth axial movement of the valve body
within the small-diameter and large-diameter portions, and the flow
path portion provided in the sliding portion allows smooth flow of
fluid.
[0018] As described above, the first aspect of the present
invention can provide the connection structure of simple structure
equipped with a valve limiting flow to a single direction (a check
valve) and featuring a small number of components and a small
number of connections with a tube, thereby reducing the cost of a
connection structure to be used in, for example, an evaporation
piping system as well as assembly work time. Furthermore, even
though the valve cap is merely fitted to the outer circumferential
surface of the end part of the nipple portion of the connection
member, since one end portion of the flexible tube is fitted to the
outer circumferential surface of the valve cap fitted to the
connection member and is further fitted to the outer
circumferential surface of the nipple portion extending away from
the outer circumferential surface of the valve cap, the connection
can exhibit low gasoline permeability. Since welding is not
necessarily required for connection of the valve cap and the end
part of the nipple portion of the connection member, low gasoline
permeability can be achieved at low cost.
[0019] According to the first aspect of the present invention, the
connection structure allows a flow adjustment bore to be axially
formed in the bottom portion of the valve body in such a manner as
to extend through the bottom portion. When the upstream fluid
pressure of the connection structure is lower than the downstream
fluid pressure, a flow path including the flow path portion is
closed. However, the flow adjustment bore formed in the bottom
portion of the valve body permits upstream flow of fluid of very
low flow rate. When the upstream fluid pressure of the connection
structure is slightly greater than the downstream fluid pressure
but is not sufficiently great to move the valve body against the
compression spring, the flow path including the flow path portion
is closed, while fluid flows downstream at a very low flow rate
through the flow adjustment bore formed in the bottom portion of
the valve body. When the upstream fluid pressure of the connection
structure becomes sufficiently greater than the downstream fluid
pressure to move the valve body against the compression spring, the
abutment part of the bottom portion of the valve body moves away
from the valve seal surface and toward the connection member,
thereby forming a gap between the abutment part and the valve seal
surface. As a result, the flow path including the flow path portion
is opened to thereby permit downstream flow of fluid of high flow
rate. That is, the flow adjustment bore formed in the bottom
portion of the valve body enables adjustment of the rate of
downstream flow of fluid according to the difference between
upstream and downstream fluid pressures of the connection
structure.
[0020] According to a second aspect of the present invention, a
valved connection member to be connected with a flexible tube
comprises a cylindrical connection member, a cylindrical valve cap,
a valve body, and a compression spring. The cylindrical connection
member comprises a cylindrical nipple portion formed at one end and
allowing the inner circumferential surface of an end portion of the
flexible tube to be fitted thereto. The cylindrical valve cap
comprises a small-diameter portion and a large-diameter portion. A
valve seal surface is formed on the inner circumferential surface
of the cylindrical valve cap and located between the small-diameter
portion and the large-diameter portion. The cylindrical valve cap
is fitted to an end part of the nipple portion of the connection
member with the large-diameter portion facing the connection
member. The valve body comprises a bottom portion having an
abutment part to abut the valve seal surface of the valve cap. The
valve body is accommodated within the large-diameter portion of the
valve cap in such a manner as to be axially slidable. The
compression spring is disposed between the large-diameter portion
of the valve cap and the nipple portion of the connection member
and adapted to bias the valve body toward the valve seal surface of
the valve cap.
[0021] The valved connection member according to the second aspect
of the present invention can form a connection structure through
fitting of one end portion of the flexible tube to the outer
circumferential surface of the valve cap fitted to the outer
circumferential surface of the end part of the nipple portion of
the connection member as well as to the outer circumferential
surface of the nipple portion extending away from the outer
circumferential surface of the valve cap. When the upstream fluid
pressure of the connection structure is lower than the downstream
fluid pressure, the abutment part of the bottom portion of the
valve body is in contact with the valve seal surface of the valve
cap to thereby close a flow path, thereby disabling flow of fluid.
In contrast, when the upstream fluid pressure becomes higher than
the downstream fluid pressure, the valve body moves toward the
connection member against the compression spring. Thus, the
abutment part of the bottom portion of the valve body moves away
from the valve seal surface and toward the connection member,
thereby opening the flow path, thereby permitting downstream flow
of fluid.
[0022] Since the valved connection member is configured such that
the valve body is accommodated within the valve cap fitted to the
connection member, the number of components required to form a
connection structure as well as the number of connections can be
reduced. Thus, the cost of the connection structure can be reduced,
and assembly work time can be shortened.
[0023] The valved connection member is configured such that the
valve cap is merely fitted to the outer circumferential surface of
the end part of the nipple portion of the connection member.
However, since one end portion of the flexible tube is fitted to
the outer circumferential surface of the valve cap fitted to the
connection member and is further fitted to the outer
circumferential surface of the nipple portion extending away from
the outer circumferential surface of the valve cap, the connection
can exhibit low gasoline permeability. Since welding is not
necessarily required for connection of the valve cap and the end
part of the nipple portion of the connection member, the cost of
the valved connection member can be reduced.
[0024] According to the second aspect of the present invention, a
valved connection member comprises a cylindrical connection member,
a cylindrical valve cap, a cylindrical valve body, and a
compression spring. The cylindrical connection member comprises a
cylindrical nipple portion formed at one end and allowing the inner
circumferential surface of an end portion of the flexible tube to
be fitted thereto; and an annular first end face portion formed at
an end part of the nipple portion in such a manner as to face
toward the one end and to extend radially. The cylindrical valve
cap comprises a small-diameter portion and a large-diameter
portion, an axial bore formed in the small-diameter portion being
smaller in diameter than an axial bore formed in the large-diameter
portion; a valve seat portion having a valve seal surface formed on
the inner circumferential surface of the cylindrical valve cap and
located between the small-diameter portion and the large-diameter
portion; and a fitting end portion formed at one end of the
large-diameter portion away from the small-diameter portion and
fitted to the outer circumferential surface of the end part of the
nipple portion of the connection member. The cylindrical valve body
comprises a bottom portion having an abutment part to abut the
valve seal surface of the valve cap; a cylindrical open end portion
extending from the bottom portion and opening toward the connection
member; an annular second end face portion formed at the open end
portion in such a manner as to face the first end face portion and
to extend radially; a first sliding portion extending radially
outward from the open end portion in an integral condition; and a
first flow path portion provided in the first sliding portion and
allowing flow of fluid. The valve body is accommodated within the
large-diameter portion of the valve cap in such a manner as to be
axially slidable by virtue of the first sliding portion. The
compression spring is disposed between the first end face portion
and the second end face portion and adapted to bias the valve body
toward the valve seat portion of the valve cap.
[0025] The valved connection member can form a connection structure
through fitting of one end portion of the flexible tube to the
outer circumferential surface of the valve cap fitted to the outer
circumferential surface of the end part of the nipple portion of
the connection member as well as to the outer circumferential
surface of the nipple portion extending away from the outer
circumferential surface of the valve cap. When the upstream fluid
pressure of the connection structure becomes higher than the
downstream fluid pressure, the valve body can axially move toward
the connection member within the large-diameter portion of the
valve cap in a smooth manner effected by the first sliding portion,
and the first flow path portion provided in the first sliding
portion permits smooth flow of fluid.
[0026] In the valved connection member according to the second
aspect of the present invention, instead of the first sliding
portion being provided on the open end portion of the valve body,
the first sliding portion can be provided on the inner
circumferential surface of the large-diameter portion of the valve
cap in the vicinity of the boundary between the large-diameter and
small-diameter portions. When the valve body moves toward the
connection member against the compression spring, the first sliding
portion provided on the valve cap allows smooth axial movement of
the valve body within the large-diameter portion, and the first
flow path portion provided in the first sliding portion allows
smooth flow of fluid.
[0027] The second aspect of the present invention allows the valve
body to further comprise a second sliding portion extending from
the bottom portion away from the open end portion and accommodated
slidably within the small-diameter portion of the valve cap; and a
second flow path portion formed in the second sliding portion and
allowing flow of fluid. The second sliding portion allows further
smooth axial movement of the valve body, and the second flow path
portion allows smooth flow of fluid at the second sliding
portion.
[0028] In the second aspect of the present invention, instead of
the first sliding portion being provided on the open end portion of
the valve body or on the inner circumferential surface of the
large-diameter portion of the valve cap in the vicinity of the
boundary between the large-diameter and small-diameter portions,
the sliding portion can be provided in such a manner as to extend
from the bottom portion away from the open end portion. When the
upstream fluid pressure of the connection structure becomes higher
than the downstream fluid pressure, so that the valve body moves
toward the connection member against the compression spring, the
sliding portion allows smooth axial movement of the valve body
within the small-diameter and large-diameter portions of the valve
cap, and the flow path portion provided in the sliding portion
allows smooth flow of fluid.
[0029] According to the second aspect of the present invention,
there can be provided a valved connection member capable of forming
at low cost a connection structure that exhibits low gasoline
permeability suited for application to, for example, an evaporation
piping system.
[0030] According to the second aspect of the present invention, the
valved connection member allows a flow adjustment bore to be
axially formed in the bottom portion of the valve body in such a
manner as to extend through the bottom portion. The flow adjustment
bore allows flow of fluid of a certain flow rate, which corresponds
to the bore size. When the upstream fluid pressure of the
connection structure becomes sufficiently greater than the
downstream fluid pressure to move the valve body against the
compression spring, a flow path including the flow path portion is
opened to thereby permit downstream flow of fluid of high flow
rate. That is, the flow adjustment bore enables adjustment of the
rate of downstream flow of fluid according to the difference
between upstream and downstream fluid pressures of the connection
structure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a schematic sectional view showing a valved
connection member according to a first embodiment of the present
invention;
[0032] FIG. 2 is a schematic side view of a valve body for use in
the valved connection member;
[0033] FIG. 3 is a schematic sectional view showing a state of the
valved connection member in which a flow path is opened;
[0034] FIG. 4 is a schematic sectional view showing an embodiment
of a connection structure using the valved connection member;
[0035] FIG. 5 is a schematic sectional view showing another
embodiment of a connection structure using the valved connection
member;
[0036] FIG. 6 is a schematic sectional view showing a modified
valved connection member of the first embodiment;
[0037] FIG. 7 is a sectional view taken along line VII-VII of FIG.
6;
[0038] FIG. 8 is a schematic sectional view showing a valved
connection member according to a second embodiment of the present
invention;
[0039] FIG. 9 is a schematic sectional view showing a state of the
valved connection member of the second embodiment in which a flow
path is opened;
[0040] FIG. 10 is a sectional view taken along line X-X of FIG.
9;
[0041] FIG. 11 is a schematic sectional view showing a valved
connection member according to a third embodiment of the present
invention;
[0042] FIG. 12 is a sectional view taken along line XII-XII of FIG.
11; and
[0043] FIG. 13 is a schematic sectional view showing a valved
connection member according to a fourth embodiment of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] A valved connection member of the preferred embodiment of
the present invention has a nipple portion at one end for
connection with a flexible tube, such as a resin tube. A valve that
limits flow to a single direction is disposed at an end of the
nipple portion. The valve is a check valve (a so-called one-way
valve) and opens a flow path to thereby allow flow from one end
thereof to the other end thereof, according to the pressure
difference between the opposite ends thereof, whereas flow in the
opposite direction is disabled.
[0045] The valved connection member of this embodiment allows
press-fitting of a flexible tube, such as a resin tube or a rubber
tube, or any other tube or hose, to the nipple portion provided at
one end of a connection member. The other end of the connection
member is generally connected to a mating member by use of, for
example, a known quick connector. However, the form of the
connection member is not limited thereto. For example, a pipe of
mating equipment may serves as the connection member such that an
end of the pipe is formed into the nipple portion.
[0046] Embodiments of the present invention will next be described
with reference to the drawings. FIG. 1 shows a valved connection
member according to a first embodiment of the present invention. A
cylindrical connection member 10 of the valved connection member
has a nipple portion 11 for connection with a flexible tube. A
plurality of circumferential protrusions 11a are formed on the
outer circumferential surface of the nipple portion 11. A valve 20,
which is a check valve, is provided at an end of the nipple portion
11. The valve 20 includes a valve cap 21, a valve body 23, and a
compression spring 26.
[0047] The cylindrical valve cap 21 includes a small-diameter
portion 21a having an axial bore formed therein, a large-diameter
portion 21b having an axial bore formed therein, and a fitting end
portion 21c. An upstream portion of the cylindrical valve cap 21 is
formed into the small-diameter portion 21a, whereas a downstream
portion is formed into the fitting end portion 21c (hereinafter the
terms "upstream" and "downstream" are used in relation to the
direction of flow in the valve 20). The axial bore of the
small-diameter portion 21a is smaller in diameter than that of the
large-diameter portion 21b. The fitting end portion 21c is fitted
onto an end part of the nipple portion 11 of the connection member
10 in such a manner as to abut a flange portion 12 provided on the
outer circumferential surface of the nipple portion 11 upstream of
the circumferential protrusions 11a, thereby being positioned. The
valve cap 21 has a valve seal surface 22 formed on an inner surface
of a valve seat portion located between the small-diameter portion
21a and the large-diameter portion 21b. The compression spring 26
biases the valve body 23 upstream such that the outer surface of
the valve body 23 is in close contact with the valve seal surface
22.
[0048] As shown in FIGS. 1 and 2, the valve body 23 is curved at a
certain curvature such that the diameter thereof increases toward
the downstream side, and includes a bottom portion 23a, which
closes the upstream end of the valve body 23. An abutment part 23b
is provided on the outer surface of the bottom portion 23a and
adapted to abut the valve seal surface 22. The valve body 23
further includes a cylindrical open end portion 23c, which opens
downstream. A plurality of second end face portions 24 each
extending radially are provided on the end face of the open end
portion 23c in such a manner as to be equally spaced along the
circumferential direction.
[0049] A plurality of first sliding portions 25a are integrally
provided on the outer circumferential surface of the open end
portion 23c along the end of the open end portion 23c in such a
condition as to project radially outward and adapted to slide on
the inner circumferential surface of the large-diameter portion 21b
of the valve cap 21. Accordingly, as shown in FIG. 1, first flow
path portion 25b is formed between the outer circumferential
surface of the open end portion 23c of the valve body 23 and the
first sliding portions 25a projecting radially outward from the
outer circumferential surface of the open end portion 23c. A
plurality of second sliding portions 25c are provided on the
upstream side of the bottom portion 23a in such a condition as to
project axially and to be equally spaced along the circumferential
direction, and are adapted to slide on the inner circumferential
surface of the small-diameter portion 21a of the valve cap 21. Gaps
between the second sliding portions 25c serve as a second flow path
portion 25d and allow flow of fluid.
[0050] The valve body 23 is accommodated within the large-diameter
portion 21b of the valve cap 21 in an axially movable condition,
while the second sliding portions 25c are inserted in the
small-diameter portion 21a of the valve cap 21. The compression
spring 26 is disposed between the second end face portions 24 of
the valve body 23 and an annular first end face portion 13 formed
on the inner circumferential surface of an end part of the nipple
portion 11 of the connection member 10 in such a manner as to
extend radially from the inner circumferential surface. The
compression spring 26 is adapted to bias the valve body 23
upstream.
[0051] The operation of the valve 20 will next be described.
[0052] In the normal state, as shown in FIG. 1, the valve body 23
is biased upstream by means of the compression spring 26; thus, the
abutment part 23b of the bottom portion 23a of the valve body 23 is
in close contact with the valve seal surface 22 of the valve cap
21. Accordingly, when the upstream fluid pressure of the valve 20
is lower than the downstream fluid pressure, a flow path including
the first flow path portion 25b is closed, thereby disabling flow
of fluid.
[0053] When the upstream fluid pressure of the valve 20 becomes
higher than the downstream fluid pressure, as shown in FIG. 3, the
valve body 23 is moved downstream against the compression spring
26. Thus, the abutment part 23b of the bottom portion 23a of the
valve body 23 moves away from the valve seal surface 22 and into
the large-diameter portion 21b of the valve cap 21, thereby forming
a gap between the abutment part 23b and the valve seal surface 22.
As a result, the flow path of the valve 20 is opened. Therefore, as
represented by the illustrated arrows, fluid flows from the
upstream side of the valve 20 to the downstream side via the second
flow path portion 25d and the first flow path portion 25b.
[0054] The valve body 23 is provided with the first sliding
portions 25a, which slide on the inner circumferential surface of
the large-diameter portion 21b of the valve cap 21, and preferably
provided with the second sliding portions 25c, which slide on the
inner circumferential surface of the small-diameter portion 21a of
the valve cap 21, thereby readily preventing inclination of the
valve body 23 when the valve body 23 is in process of moving or
resting on the valve seal surface 22. Thus, the valve body 23 moves
smoothly within the valve cap 21 along the axial direction, and
fluid flows smoothly through the first and second flow path
portions 25b and 25d.
[0055] The valve 20 according to the present embodiment is attached
to the end part of the nipple portion 11 of the connection member
10. The valve cap 21 and the nipple portion 11 can be fixedly
engaged through press-fitting or bonding. A resin or rubber tube or
a like tube is connected to the nipple portion 11. Thus, as shown
in FIG. 4, after the valve cap 21, into which, for example, the
valve body 23 and the compression spring 26 are incorporated, is
attached to the nipple portion 11 in a removable condition, a tube
1 is press-fitted to the nipple portion 11. Since the
circumferential protrusions 11a prevent slipping-out of the tube 1,
the valve cap 21 can be reliably held in place without use of
press-fitting or adhesive.
[0056] Since the valve is configured such that the valve body 23 is
accommodated within the valve cap 21 fitted to the connection
member 10, the number of components as well as the number of
connections can be reduced. Thus, the cost of the connection
structure can be reduced, and assembly work time can be shortened.
Furthermore, although the valve cap 21 is merely fitted to the
outer circumferential surface of the end part of the nipple portion
11 of the connection member 10, since one end portion of the tube
is fitted to the outer circumferential surface of the valve cap 21
fitted to the connection member 10 and is further fitted to the
outer circumferential surface of the nipple portion 11 extending
downstream of the outer circumferential surface of the valve cap
21, the connection can exhibit low gasoline permeability. Since
welding is not required for connection of the valve cap 21 and the
end part of the nipple portion 11 of the connection member 10, the
cost of connection can be reduced.
[0057] As shown in FIG. 4, for example, a pipe of equipment 3 can
serve as the nipple portion 11 of the connection member 10.
However, usually, as shown in FIG. 5, the downstream end of the
connection member 11 assumes the form of a connector for connection
with a mating member 2.
[0058] FIG. 5 shows another embodiment of a connection structure
using a valved connection member. The valve 20 is attached to the
nipple portion 11 located at the upstream end of the connection
member 10, and the resin tube 1 is connected to the nipple portion
11 in such a manner as to cover the valve 20. The mating member 2
is connected to the connector portion located at the downstream end
of the connection member 10.
[0059] In FIG. 5, the connector portion of the connection member 10
assumes the form of a known quick connector. The connector portion
comprises a cylindrical housing 30 extending from the nipple
portion 11 to the downstream end of the connection member 10 and an
engagement member 31 which assumes a substantially cylindrical form
having a gradually increasing diameter and which is cut in at least
a single position so as to be elastically deformable. The
engagement member 31 is attached to the housing 30 in the following
manner. The engagement member 31 is inserted into the housing 30
through an end opening thereof while being squeezed, and is then
snap-engaged with a window portion 33 formed in the housing 30.
Notably, seal members 32, such as O-rings, are disposed within the
housing 30 in order to seal the space between the housing 30 and
the mating member 2.
[0060] The mating member 2 is inserted into the housing 30 through
a downstream end opening formed in the engagement member 31. The
upstream end of the engagement member 31 is expanded radially so as
to allow passage of a circumferential protrusion 2a of the mating
member 2 and then narrowed radially so as to be engaged with the
circumferential protrusion 2a, thereby establishing engagement with
the mating member 2. The engagement member 31 includes an operation
arm portion 34 located at the downstream end. When the mating
member 2 is to be removed, a user presses the operation arm portion
34 radially inward so as to squeeze the entire engagement member
31.
[0061] Next will be described a modified valved connection member
of the above-described first embodiment. In contrast to the first
embodiment, in which the first sliding portions 2a are provided on
the open end portion 23c of the valve body 23, as shown in FIGS. 6
and 7, a valved connection member of the modified embodiment
includes a plurality of first sliding portions 21A provided on the
inner circumferential surface of the large-diameter portion 21b in
the vicinity of the boundary between the small-diameter portion 21a
and the large-diameter portion 21b. The first sliding portions 21A
project radially inward from the inner circumferential surface of
the large-diameter portion 21b and are arranged along the
circumferential direction. Gaps between the first sliding portions
21A serve as a first flow path portion 21B. According to the
present modified embodiment, when the upstream fluid pressure of
the connection structure becomes higher than the downstream fluid
pressure, so that the valve body 23 moves downstream against the
compression spring 26, the first sliding portions 21A allow smooth
axial movement of the valve body 23 within the large-diameter
portion 21b, and the first flow path portion 21B provided in the
first sliding portions 21A allows smooth flow of fluid.
[0062] Next, a second embodiment of the present invention will be
described with reference to FIGS. 8 to 10. A valved connection
member of the present embodiment is not provided with a sliding
portion on the upstream side of the valve body 23 but is provided
only with a sliding portion on the downstream side of the valve
body 23. A valve cap 51 of a valve 50 of the present embodiment
includes an upstream small-diameter portion 51a and a downstream
large-diameter portion 51b. An end part of the large-diameter
portion 51b is fitted onto an end part of a nipple portion 41 of
the connection member 10 in such a manner as to abut a flange
portion 42 provided on the outer circumferential surface of the
nipple portion 41 upstream of circumferential protrusions 41a,
thereby being positioned. The valve cap 51 has a valve seal surface
52 formed on its inner surface and located between the
small-diameter portion 51a and the large-diameter portion 51b. A
compression spring 56 biases a valve body 53 upstream such that an
abutment part 53b of the outer surface of the valve body 53 is in
close contact with the valve seal surface 52.
[0063] The valve body 53 includes a bottom portion 53a, which
closes the upstream end of the valve body 53. The abutment part 53b
is provided on the outer surface of the bottom portion 53a and
adapted to abut the valve seal surface 52. A plurality of first
sliding portions 55a are formed on the downstream side of the
bottom portion 53a in such a condition as to be equally spaced
along the circumferential direction and to project radially
outward. The downstream side of each of the first sliding portions
55a serves as a second end face portion 54, which extend radially.
Gaps between the first sliding portions 55a serve as a first flow
path portion 55b, through which fluid flows. Also, a plurality of
axially projecting sliding portions 55c are provided on the
downstream side of the bottom portion 53 in such a condition as to
be slidable on the inner circumferential surface of the nipple
portion 41 and equally spaced along the circumferential direction
and extending axially.
[0064] The valve body 53 is accommodated within the large-diameter
portion 51b of the valve cap 51 in an axially slidable condition
and such that the axially projecting sliding portions 55c are
inserted into the nipple portion 41. The compression spring 56 is
disposed between the second end face portions 54 of the valve body
53 and an annular first end face portion 43 formed on the inner
circumferential surface of an end part of the nipple portion 41 in
such a manner as to extend radially from the inner circumferential
surface. The compression spring 56 is adapted to bias the valve
body 53 upstream.
[0065] The valve 50 of the second embodiment also operates in a
manner similar to that of the first embodiment. Specifically, in
the normal state, as shown in FIG. 8, the valve body 53 is biased
upstream by means of the compression spring 56; thus, the abutment
part 53b of the bottom portion 53a of the valve body 53 is in close
contact with the valve seal surface 52 of the valve cap 51.
Accordingly, when the upstream fluid pressure of the valve 50 is
lower than the downstream fluid pressure, a flow path is closed.
When the upstream fluid pressure of the valve 50 becomes higher
than the downstream fluid pressure, as shown in FIG. 9, the valve
body 53 is moved downstream against the compression spring 56.
Thus, the abutment part 53b moves downstream away from the valve
seal surface 52, thereby forming a gap between the abutment part
53b and the valve seal surface 52. As a result, the flow path of
the valve 50 is opened. Therefore, as represented by the
illustrated arrows, fluid flows downstream via the first flow path
portion 55b.
[0066] In the valve body 53 of the second embodiment, the first
sliding portions 55a--which slide on the inner circumferential
surface of the large-diameter portion 51b of the valve cap 51--and
the axially projecting sliding portions 55c which slide on the
inner circumferential surface of the nipple portion 41 of the
connection member 40--readily prevent inclination of the valve body
53 when the valve body 53 is in process of moving axially or
resting on the valve seal surface 52. Thus, the valve body 53 moves
smoothly within the valve cap 51 along the axial direction, and
fluid flows smoothly through the first flow path portion 55b.
[0067] Next, a third embodiment of the present invention will be
described with reference to FIGS. 11 to 12. A valved connection
member of the present embodiment differs from that of the
above-described first embodiment in that a sliding portion is not
provided on the open end portion 23c of the valve body 23 but is
provided only on the upstream side of the bottom portion 23a.
Specifically, a plurality of sliding portions 27 integrally project
in an axial direction from the upstream side of the bottom portion
23a in a circumferentially arranged condition. Gaps between the
sliding portions 27 serve as a flow path portion 27a. When the
upstream fluid pressure of the connection structure becomes higher
than the downstream fluid pressure; thus, the valve body 23 is
moved downstream against the compression spring 26, the sliding
portions 27 allow smooth axial movement of the valve body 23 within
the small-diameter portion 21a and large-diameter portion 21b, and
the flow path portion 27a provided in the sliding portions 27
allows smooth flow of fluid. Thus, the valved connection member of
the third embodiment is simpler in structure than that of the first
embodiment but yields actions and effects similar to those yielded
by the valved connection member of the first embodiment.
[0068] Next, a fourth embodiment of the present invention will be
described with reference to FIG. 13. A valved connection member of
the present embodiment differs from that of the above-described
first embodiment in that a flow adjustment bore 28 is formed in the
bottom portion 23a of the valve body 23 in such a manner as to
extend through the bottom portion 23a.
[0069] According to the present embodiment, when the upstream fluid
pressure of a connection structure is lower than the upstream fluid
pressure, a flow path including the first flow path portion 25b is
closed. However, the flow adjustment bore 28 formed in the bottom
portion 23a permits downstream flow of fluid of very low flow rate.
When the upstream fluid pressure of the connection structure is
slightly greater than the downstream fluid pressure but is not
sufficiently great to move the valve body 23 against the
compression spring 26, the flow path including the first flow path
portion 25b is closed, while fluid flows downstream at a very low
flow rate through the flow adjustment bore 28.
[0070] When the upstream fluid pressure of the connection structure
becomes sufficiently greater than the downstream fluid pressure to
move the valve body 23 against the compression spring 26, the
abutment part 23b of the bottom portion 23a of the valve body 23
moves away from the valve seal surface 22 and downstream of the
large-diameter portion 21b, thereby forming a gap between the
abutment part 23b and the valve seal surface 22. As a result, the
flow path including the first flow path portion 25b is opened to
thereby permit downstream flow of fluid of high flow rate. That is,
according to the present embodiment, the rate of downstream flow of
fluid can be adjusted according to the difference between upstream
and downstream fluid pressures of the connection structure.
Notably, the above-described other embodiments and modified
embodiment may have a similar flow adjustment bore formed in the
bottom portion of the valve body to thereby yield the
above-described effect.
[0071] In the above-described valved connection members of the
present invention, all components but the spring can be made of
synthetic resins. For example, preferably, the connection member
including the nipple portion is made of nylon, and the valve cap
and the valve body are made of polyacetal. The spring is made of
metal, such as stainless steel. A tube to be connected to the
nipple portion of the connection member is not particularly
limited. For example, the tube is a resin or rubber tube.
* * * * *