U.S. patent application number 11/291337 was filed with the patent office on 2006-06-08 for pressure control valve.
This patent application is currently assigned to Fujikoki Corporation. Invention is credited to Sadatake Ise, Shu Yanagisawa.
Application Number | 20060117774 11/291337 |
Document ID | / |
Family ID | 35788423 |
Filed Date | 2006-06-08 |
United States Patent
Application |
20060117774 |
Kind Code |
A1 |
Ise; Sadatake ; et
al. |
June 8, 2006 |
Pressure control valve
Abstract
A pressure control valve to be integrated into a
steam-compression type refrigerating cycle includes: a
temperature-sensing cylinder for sensing the temperature of
refrigerant on the outlet side of the gas cooler; a
temperature-sensing pressure responding element provided with a
temperature-sensing chamber communicating through a capillary tube
with the temperature-sensing cylinder and designed to drive a valve
body into a closed or open state in response to fluctuations of
inner pressure of the temperature-sensing chamber; and a valve main
body attached to the pressure responding element; wherein the
temperature-sensing cylinder and the temperature-sensing chamber
are filled with CO2 at a predetermined density and also with a
bulking quantity of an inert gas, thereby enabling to adjust the
pressure of refrigerant on the outlet side of the gas cooler in
order to secure a maximum coefficient of performance relative to
the temperature of refrigerant on the outlet side of the gas
cooler.
Inventors: |
Ise; Sadatake; (Tokyo,
JP) ; Yanagisawa; Shu; (Tokyo, JP) |
Correspondence
Address: |
BAKER & BOTTS
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
Fujikoki Corporation
Tokyo
JP
|
Family ID: |
35788423 |
Appl. No.: |
11/291337 |
Filed: |
December 1, 2005 |
Current U.S.
Class: |
62/222 ;
62/527 |
Current CPC
Class: |
F25B 2500/01 20130101;
F25B 2309/06 20130101; F25B 2341/0683 20130101; F25B 41/31
20210101; F25B 2309/061 20130101; F25B 40/00 20130101 |
Class at
Publication: |
062/222 ;
062/527 |
International
Class: |
F25B 41/04 20060101
F25B041/04; F25B 41/06 20060101 F25B041/06 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 1, 2004 |
JP |
2004-348850 |
Dec 1, 2004 |
JP |
2004-348889 |
Claims
1. A pressure control valve which is adapted to be integrated into
a steam-compression refrigerating cycle which comprises: a
compressor for circulating CO2 employed as a refrigerant, a gas
cooler for cooling the refrigerant that has been compressed by the
compressor, an evaporator into which the refrigerant is designed to
be introduced from the gas cooler, and an internal heat exchanger
for performing heat exchange between the refrigerant on the outlet
side of the evaporator and the refrigerant on the outlet side of
the gas cooler; the pressure control valve being constructed to
pass the refrigerant to the evaporator after adjusting, depending
on the temperature of the refrigerant on the outlet side of the gas
cooler, the pressure of the refrigerant that has been introduced
therein via the internal heat exchanger from the gas cooler; said
pressure control valve comprising: a temperature-sensing cylinder
for sensing the temperature of the refrigerant on the outlet side
of the gas cooler; a temperature-sensing pressure responding
element which is provided with a temperature-sensing chamber
communicating through a capillary tube with the temperature-sensing
cylinder and designed to drive a valve body into a closed or open
state in response to fluctuations of inner pressure of the
temperature-sensing chamber; and a valve main body attached to the
pressure responding element; wherein the temperature-sensing
cylinder and the temperature-sensing chamber are filled with CO2 at
a predetermined density and also with a bulking quantity of an
inert gas, thereby enabling to adjust the pressure of refrigerant
on the outlet side of the gas cooler in order to secure a maximum
coefficient of performance relative to the temperature of
refrigerant on the outlet side of the gas cooler.
2. A pressure control valve which is adapted to be disposed in the
vicinity of the gas cooler or in the vicinity of the outlet port of
the gas cooler of a steam-compression refrigerating cycle which
comprises: a compressor for circulating CO2 employed as a
refrigerant, a gas cooler for cooling the refrigerant that has been
compressed by the compressor, an evaporator into which the
refrigerant is designed to be introduced from the gas cooler, and
an internal heat exchanger for performing heat exchange between the
refrigerant on the outlet side of the evaporator and the
refrigerant on the outlet side of the gas cooler; the pressure
control valve being constructed to pass the refrigerant to the
evaporator after adjusting, depending on the temperature of the
refrigerant on the outlet side of the gas cooler, the pressure of
the refrigerant that has been introduced therein via the internal
heat exchanger from the gas cooler; said pressure control valve
comprising: a temperature-sensing pressure responding element which
is provided with a temperature-sensing chamber for sensing the
temperature of refrigerant on the outlet side of the gas cooler and
designed to drive a valve body into a closed or open state in
response to fluctuations of inner pressure of the
temperature-sensing chamber; and a valve main body attached to the
pressure responding element; wherein the temperature-sensing
chamber is filled with CO2 at a predetermined density and also with
a bulking quantity of an inert gas, thereby enabling to adjust the
pressure of refrigerant on the outlet side of the gas cooler in
order to secure a maximum coefficient of performance relative to
the temperature of refrigerant on the outlet side of the gas
cooler.
3. The pressure control valve according to claim 1, wherein the
valve main body is formed of an approximately rectangular
parallelepiped body which is cut out from an extruded rod having a
rectangular cross-section and provided with a refrigerant entrance
port, a mounting portion for the pressure responding element, and a
valve seat portion for removably receiving the valve body.
4. The pressure control valve according to claim 2, wherein the
valve main body is formed of an approximately rectangular
parallelepiped body which is cut out from an extruded rod having a
rectangular cross-section and provided with a refrigerant entrance
port, a mounting portion for the pressure responding element, and a
valve seat portion for removably receiving the valve body.
5. The pressure control valve according to claim 1, wherein the
valve main body is provided with at least one engaging portion
selected from an external thread portion, a flange portion, an
internal thread portion for receiving bolts, and an insertion hole
for attaching the valve main body to a pipe coupler or to the
internal heat exchanger.
6. The pressure control valve according to claim 2, wherein the
valve main body is provided with at least one engaging portion
selected from an external thread portion, a flange portion, an
internal thread portion for receiving bolts, and an insertion hole
for attaching the valve main body to a pipe coupler or to the
internal heat exchanger.
7. The pressure control valve according to claim 1, wherein the
temperature-sensing pressure responding element comprises a
diaphragm; a cap member having an inverted U-shaped cross-section
for partitioning, in cooperation with the diaphragm, the
temperature-sensing chamber; and a cylindrical cap-receiving member
for holding, in cooperation with the cap member, an outer
circumferential portion of the diaphragm to hermetically seal the
pressure responding element, the cylindrical cap-receiving member
comprising a flange portion for enabling the valve body to be
slidably inserted therein; wherein the cap-receiving member is
additionally provided on an outer circumferential wall of the
cylindrical portion thereof with an external thread for attaching
the pressure responding element to the valve main body.
8. The pressure control valve according to claim 2, wherein the
temperature-sensing pressure responding element comprises a
diaphragm; a cap member having an inverted U-shaped cross-section
for partitioning, in cooperation with the diaphragm, the
temperature-sensing chamber; and a cylindrical cap-receiving member
for holding, in cooperation with the cap member, an outer
circumferential portion of the diaphragm to hermetically seal the
pressure responding element, the cylindrical cap-receiving member
comprising a flange portion for enabling the valve body to be
slidably inserted therein; wherein the cap-receiving member is
additionally provided on an outer circumferential wall of the
cylindrical portion thereof with an external thread for attaching
the pressure responding element to the valve main body.
9. The pressure control valve according to claim 1, wherein the
valve main body is further provided therein with a restraining
spring for suppressing the vibration of the valve body.
10. The pressure control valve according to claim 2, wherein the
valve main body is further provided therein with a restraining
spring for suppressing the vibration of the valve body.
11. The pressure control valve according to claim 9, wherein the
restraining spring for vibration is formed of an elastic plate and
comprises a generally annular bottom portion having an inverted
V-shaped cross-section and being press-contacted with the valve
main body by the cap-receiving member, and by a plurality of
tongue-shaped flexible flaps extending upward from an inner
periphery of the annular bottom portion and elastically contacted
with an outer circumferential wall of the valve body.
12. The pressure control valve according to claim 10, wherein the
restraining spring for vibration is formed of an elastic plate and
comprises a generally annular bottom portion having an inverted
V-shaped cross-section and being press-contacted with the valve
main body by the cap-receiving member, and by a plurality of
tongue-shaped flexible flaps extending upward from an inner
periphery of the annular bottom portion and elastically contacted
with an outer circumferential wall of the valve body.
13. The pressure control valve according to claim 7, wherein the
valve body and the diaphragm are disposed coaxially and one end
portion of the valve body is bonded to the diaphragm by projection
welding.
14. The pressure control valve according to claim 8, wherein the
valve body and the diaphragm are disposed coaxially and one end
portion of the valve body is bonded to the diaphragm by projection
welding.
15. The pressure control valve according to claim 7, wherein the
diaphragm comprises a closed-end shortened cylindrical body, and an
outer edge portion and cylindrical portion of the diaphragm are
held between the cap member and the cap-receiving member to
hermetically seal the pressure responding element, wherein the
lower end portion of this laminated portion is welded to each other
throughout the entire periphery thereof.
16. The pressure control valve according to claim 8, wherein the
diaphragm comprises a closed-end shortened cylindrical body, and an
outer edge portion and cylindrical portion of the diaphragm are
held between the cap member and the cap-receiving member to
hermetically seal the pressure responding element, wherein the
lower end portion of this laminated portion is welded to each other
throughout the entire periphery thereof.
17. The pressure control valve according to claim 7, wherein the
cap-receiving member comprises a cylindrical portion having an
external thread portion, and a flange portion which can be
manufactured by press-working a plate.
18. The pressure control valve according to claim 8, wherein the
cap-receiving member comprises a cylindrical portion having an
external thread portion, and a flange portion which can be
manufactured by press-working a plate.
19. The pressure control valve according to claim 2, wherein the
temperature-sensing chamber comprises, on an outer circumference
thereof, with temperature-sensing fins, or with a
temperature-sensing fin-attached cylindrical or cap body.
20. The pressure control valve according to claim 1, wherein the
valve body is partitioned into an axis portion and an enlarged
portion.
21. The pressure control valve according to claim 2, wherein the
valve body is partitioned into an axis portion and an enlarged
portion.
22. The pressure control valve according to claim 1, wherein the
valve seat of the valve main body comprises a plurality of bleed
notches.
23. The pressure control valve according to claim 2, wherein the
valve seat of the valve main body comprises a plurality of bleed
notches.
24. A pressure control valve which is adapted to be integrated into
a steam-compression refrigerating cycle which comprises: a
compressor for circulating CO2 employed as a refrigerant, a gas
cooler for cooling the refrigerant that has been compressed by the
compressor, an evaporator into which the refrigerant is designed to
be introduced from the gas cooler, and an internal heat exchanger
for performing heat exchange between the refrigerant on the outlet
side of the evaporator and the refrigerant on the outlet side of
the gas cooler; the pressure control valve being constructed to
pass the refrigerant to the evaporator after adjusting, depending
on the temperature of the refrigerant on the outlet side of the gas
cooler, the pressure of the refrigerant that has been introduced
therein via the internal heat exchanger from the gas cooler; said
pressure control valve comprising: a temperature-sensing inlet port
for introducing therein the refrigerant from the gas cooler; a
temperature-sensing outlet port for sending the refrigerant to the
internal heat exchanger; a temperature-sensing introduction chamber
interposed between the temperature-sensing inlet port and the
temperature-sensing outlet port; a temperature-sensing pressure
responding element comprising a temperature-sensing chamber for
sensing the temperature of the refrigerant that has been introduced
into the temperature-sensing introduction chamber, the
temperature-sensing pressure responding element being further
capable of driving a valve body into a closed or open state in
response to fluctuations of inner pressure of the
temperature-sensing chamber; and a valve main body to which the
temperature-sensing pressure responding element can be attached;
wherein the temperature-sensing chamber is filled with CO2 at a
predetermined density and also with a bulking quantity of an inert
gas, thereby enabling to adjust the pressure of refrigerant on the
outlet side of the gas cooler in order to secure a maximum
coefficient of performance relative to the temperature of
refrigerant on the outlet side of the gas cooler.
25. The pressure control valve according to claim 24, wherein the
valve main body comprises a solid body which is cut out from an
extruded rod having a plus-shape or rectangular cross-section and
provided with the temperature-sensing inlet port, the
temperature-sensing outlet port, the temperature-sensing
introduction chamber, the pressure-adjusting inlet port, the
pressure-adjusting outlet port, a mounting portion for the pressure
responding element, and a valve seat portion for removably
receiving the valve body.
26. The pressure control valve according to claim 25, wherein a
guide hole for enabling the valve body to be slidably inserted
therein is provided over the valve seat of the valve main body,
wherein the temperature-sensing inlet port, temperature-sensing
outlet port and temperature-sensing introduction chamber are
disposed over the guide hole, and the pressure-adjusting inlet
port, pressure-adjusting outlet port and a valve chamber are
disposed below the guide hole.
27. The pressure control valve according to claim 24, wherein the
valve main body is provided with at least one engaging portion
selected from an external thread portion, a flange portion, an
internal thread portion for receiving bolts, and an insertion hole
for attaching the valve main body to the gas cooler, to a pipe
coupler for connection with the evaporator, or to the internal heat
exchanger.
28. The pressure control valve according to claim 24, wherein the
temperature-sensing pressure responding element comprises a
diaphragm; a cap member having an inverted U-shaped cross-section
for partitioning, in cooperation with the diaphragm, the
temperature-sensing chamber; and a cylindrical cap-receiving member
for holding, in cooperation with the cap member, an outer
circumferential portion of the diaphragm to hermetically seal the
pressure responding element, the cylindrical cap-receiving member
comprising a flange portion for enabling the valve body to be
inserted therein through the inner periphery thereof; wherein the
cap-receiving member is additionally provided on an outer
circumferential wall of the cylindrical portion thereof with an
external thread for attaching the pressure responding element to
the valve main body.
29. The pressure control valve according to claim 28, wherein the
valve body and the diaphragm are disposed coaxially and one end
portion of the valve body is bonded to the diaphragm by projection
welding.
30. The pressure control valve according to claim 13, wherein the
valve body comprises a columnar valve rod, and a valve body portion
formed at a lower end portion of the valve rod, wherein the valve
rod comprises a shaft portion, and an enlarged portion which is
formed integral with or fixedly secured to an upper portion of the
shaft portion, the diaphragm being coupled to an upper surface of
the enlarged portion.
31. The pressure control valve according to claim 29, wherein the
valve body comprises a columnar valve rod, and a valve body portion
formed at a lower end portion of the valve rod, wherein the valve
rod comprises a shaft portion, and an enlarged portion which is
formed integral with or fixedly secured to an upper portion of the
shaft portion, the diaphragm being coupled to an upper surface of
the enlarged portion.
32. The pressure control valve according to claim 28, wherein the
temperature-sensing introduction chamber is formed between the
valve rod and the cylindrical portion of the cap-receiving
member.
33. The pressure control valve according to claim 28, wherein the
valve body is provided with a longitudinal hole having an open top,
and the diaphragm is provided with a through-hole for enabling the
temperature-sensing chamber to the longitudinal hole, thereby
constituting one extended temperature-sensing chamber comprising
the temperature-sensing chamber and the longitudinal hole.
34. The pressure control valve according to claim 28, wherein the
diaphragm is formed of a closed-end shortened cylindrical body, and
the outer edge portion and cylindrical portion of the diaphragm are
held between the cap member and the cap-receiving member to
hermetically seal the pressure responding element, wherein the
lower end portion of the laminated portion is welded to each other
throughout the entire periphery thereof.
35. The pressure control valve according to claim 25, wherein the
valve body is provided, along the whole length of the
circumferential wall thereof, with a trench for interrupting heat
transmission between the temperature-sensing inlet port and the
temperature-sensing outlet port, and between the pressure-adjusting
inlet port and the pressure-adjusting outlet port.
36. The pressure control valve according to claim 25, wherein the
valve seat of the valve main body comprises a plurality of bleed
notches.
37. The pressure control valve according to claim 30, wherein the
valve rod of the valve body comprises a plurality of annular
trenches.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a pressure control valve
which is adapted to be integrated into a steam-compression type
refrigerating cycle where CO2 is employed as a refrigerant (CO2
cycle) for adjusting the pressure of refrigerant on the gas cooler
(radiator) outlet side in conformity with the temperature of
refrigerant. In particular, the present invention relates to a
pressure control valve which is suitable for use in a
steam-compression type refrigerating cycle to be employed in a car
air conditioner provided with an internal heat exchanger for
performing heat exchange between the refrigerant on the outlet side
of an evaporator and the refrigerant on the outlet side of the gas
cooler.
BACKGROUND INFORMATION
[0002] FIG. 21 shows one example of the steam-compression type
refrigerating cycle into which a pressure control valve of this
kind is integrated. The refrigerating cycle 100 shown herein is
constituted by: a compressor 101 for circulating CO2 employed as a
refrigerant; a gas cooler (radiator) 102 for cooling the
refrigerant that has been compressed by the compressor 101; an
evaporator 104 into which the refrigerant is designed to be
introduced from the gas cooler 102; an internal heat exchanger 103
for performing heat exchange between the refrigerant on the outlet
side of the evaporator 104 and the refrigerant on the outlet side
of the gas cooler 102; an accumulator (gas-liquid separator) 105
for dividing the refrigerant from the evaporator 104 into a gas
phase refrigerant and a liquid phase refrigerant and for
introducing the gas phase refrigerant into the intake side of the
compressor 101 through the heat exchanger 103 while accumulating
surplus refrigerant; and a pressure control valve 110 for passing
the refrigerant to the evaporator 104 after adjusting, depending on
the temperature of the refrigerant on the outlet side of the gas
cooler 102, the pressure of the refrigerant that has been
introduced via the internal heat exchanger 103 into the pressure
control valve 110 from the gas cooler 102.
[0003] The pressure control valve 110 is provided for effectively
operating the refrigerating cycle 100. In other words, the pressure
control valve 110 is provided for adjusting the pressure of the
refrigerant on the outlet side of the gas cooler 102 so as to
secure a maximum coefficient of performance relative to the
temperature of refrigerant on the outlet side of the gas cooler 102
(For example, under the condition where the temperature of the
refrigerant on the outlet side is 40.degree. C., when the
coefficient of performance can be made maximum if the pressure of
the refrigerant on the outlet side is set to 10 MPa, the pressure
control valve 110 is controlled so that the pressure of the
refrigerant on the outlet side may become 10 MPa). As shown in JP
Laid-open Patent Publication (Kokai) No. 2001-81157 for example,
this pressure control valve 110 is provided with: a
pressure-adjusting inlet port 111 for introducing therein the
refrigerant from the gas cooler 102 through the internal heat
exchanger 103; a pressure-adjusting outlet port 112 for sending the
refrigerant to the evaporator 104 after adjusting the pressure of
the refrigerant depending on the temperature of the refrigerant on
the outlet side of the gas cooler 102; a temperature-sensing inlet
port 113 for introducing therein the refrigerant from the gas
cooler 102; a temperature-sensing outlet port 114 for sending the
refrigerant to the internal heat exchanger 103; a
temperature-sensing introduction chamber (not shown) interposed
between the temperature-sensing inlet port 113 and the
temperature-sensing outlet port 114; a temperature-sensing pressure
responding element (not shown) including a temperature-sensing
chamber for sensing the temperature of the refrigerant that has
been introduced into the temperature-sensing introduction chamber,
the temperature-sensing pressure responding element being further
capable of driving a valve body into a closed or open state in
response to fluctuations of inner pressure of the
temperature-sensing chamber; a valve main body (the entire control
valve shown herein) having the temperature-sensing pressure
responding element accommodated therein; and a spring member (not
shown) disposed inside the valve main body and urging the valve
body to move in the direction to reduce the opening degree of valve
(valve-closing direction); wherein the opening degree of valve (the
lifting quantity of the valve body) is determined by a balance
between the valve-opening force originating from a pressure
difference between the inside and outside of the
temperature-sensing chamber and the valve-closing force by the
spring member.
SUMMARY OF THE INVENTION
[0004] Even in the case of the pressure control valve mentioned
above, there is an increasing demand to reduce the manufacturing
cost, so that there are strong demands to simplify the structure
thereof, to decrease the number of parts, and to reduce the working
and assembling cost.
[0005] The present invention has been made in response to the
demands mentioned above and, therefore, an object of the present
invention to provide a pressure control valve which is capable of
appropriately adjusting the pressure of the refrigerant on the
outlet side of the gas cooler in conformity with the temperature of
the refrigerant on this outlet side, and also capable of
effectively realizing the simplification of the structure thereof,
the reduction of the number of parts, and the reduction of the
working and assembling cost.
[0006] With a view to attaining the aforementioned object, there is
provided, according to one aspect of the present invention, a
pressure control valve which is adapted to be integrated into a
steam-compression type refrigerating cycle which is constituted
fundamentally by: a compressor for circulating CO2 employed as a
refrigerant, a gas cooler for cooling the refrigerant that has been
compressed by the compressor, an evaporator into which the
refrigerant is designed to be introduced from the gas cooler, and
an internal heat exchanger for performing heat exchange between the
refrigerant on the outlet side of the evaporator and the
refrigerant on the outlet side of the gas cooler; the pressure
control valve being constructed to pass the refrigerant to the
evaporator after adjusting, depending on the temperature of the
refrigerant on the outlet side of the gas cooler, the pressure of
the refrigerant that has been introduced therein via the internal
heat exchanger from the gas cooler.
[0007] This pressure control valve includes a temperature-sensing
cylinder for sensing the temperature of the refrigerant on the
outlet side of the gas cooler, a temperature-sensing pressure
responding element which is provided with a temperature-sensing
chamber communicating through a capillary tube with the
temperature-sensing cylinder and designed to drive a valve body
into a closed or open state in response to fluctuations of inner
pressure of the temperature-sensing chamber, and a valve main body
attached integrally to the pressure responding element, wherein the
temperature-sensing cylinder and the temperature-sensing chamber
are filled with CO2 at a predetermined density and also with a
bulking quantity of an inert gas, thereby enabling to adjust the
pressure of refrigerant on the outlet side of the gas cooler in
order to secure a maximum coefficient of performance relative to
the temperature of refrigerant on the outlet side of the gas
cooler.
[0008] According to a second aspect of the present invention, there
is provided a pressure control valve which is adapted to be
disposed in the vicinity of the gas cooler or in the vicinity of
the outlet port of the gas cooler of a steam-compression type
refrigerating cycle which is constituted fundamentally by: a
compressor for circulating CO2 employed as a refrigerant, a gas
cooler for cooling the refrigerant that has been compressed by the
compressor, an evaporator into which the refrigerant is designed to
be introduced from the gas cooler, and an internal heat exchanger
for performing heat exchange between the refrigerant on the outlet
side of the evaporator and the refrigerant on the outlet side of
the gas cooler; the pressure control valve being constructed to
pass the refrigerant to the evaporator after adjusting, depending
on the temperature of the refrigerant on the outlet side of the gas
cooler, the pressure of the refrigerant that has been introduced
therein via the internal heat exchanger from the gas cooler.
[0009] This pressure control valve includes a temperature-sensing
pressure responding element which is provided with a
temperature-sensing chamber for sensing the temperature of
refrigerant on the outlet side of the gas cooler and designed to
drive a valve body into a closed or open state in response to
fluctuations of inner pressure of the temperature-sensing chamber,
and a valve main body attached integrally to the pressure
responding element, wherein the temperature-sensing chamber is
filled with CO2 at a predetermined density and also with a bulking
quantity of an inert gas, thereby enabling to adjust the pressure
of refrigerant on the outlet side of the gas cooler in order to
secure a maximum coefficient of performance relative to the
temperature of refrigerant on the outlet side of the gas
cooler.
[0010] Preferably, the valve main body is formed of an
approximately rectangular parallelepiped body which is cut out from
an extruded rod having a rectangular cross-section and provided
with a refrigerant entrance port, a mounting portion for the
pressure responding element, and a valve seat portion for removably
receiving the valve body.
[0011] In a preferable embodiment, the valve main body is provided
with at least one engaging portion selected from an external thread
portion, a flange portion, an internal thread portion for receiving
bolts, and an insertion hole for mounting the valve main body on
the gas cooler or on the internal heat exchanger.
[0012] Preferably, the temperature-sensing pressure responding
element is constituted by a diaphragm; a cap member having an
inverted U-shaped cross-section for partitioning, in cooperation
with the diaphragm, the temperature-sensing chamber; and a
cylindrical cap-receiving member for holding, in cooperation with
the cap member, an outer circumferential portion of the diaphragm
to hermetically seal the pressure responding element, the
cylindrical cap-receiving member including a flange portion for
enabling the valve body to be slidably inserted therein; wherein
the cap-receiving member is additionally provided on an outer
circumferential wall of the cylindrical portion thereof with an
external thread for attaching the pressure responding element to
the valve main body.
[0013] In a further preferable embodiment, the valve main body is
further provided therein with a restraining spring for suppressing
the vibration of the valve body. In this case, the restraining
spring for vibration is preferably formed of an elastic plate and
constituted by a generally annular bottom portion having an
inverted V-shaped cross-section and being press-contacted with the
valve main body by means of the cap-receiving member, and by a
plurality of tongue-shaped flexible flaps extending upward from an
inner periphery of the annular bottom portion and elastically
contacted with the outer circumferential wall of the valve
body.
[0014] In a further preferable embodiment, the valve body and the
diaphragm are disposed coaxially and one end portion of the valve
body is bonded to the diaphragm by means of projection welding.
[0015] In a still further preferable embodiment, the diaphragm is
formed of a closed-end shortened cylindrical body, and the outer
edge portion and cylindrical portion of the diaphragm are held
between the cap member and the cap-receiving member to hermetically
seal the pressure responding element, wherein the lower end portion
of this laminated portion is welded to each other throughout the
entire periphery thereof.
[0016] Preferably, the cap-receiving member is formed of two parts,
i.e. a cylindrical portion having an external thread portion, and a
flange portion which can be manufactured by press-working a
plate.
[0017] In the pressure control valve according to the second aspect
of the present invention, the temperature-sensing chamber is
provided, on the outer circumference thereof, with
temperature-sensing fins, or with a temperature-sensing
fin-attached cylindrical or cap body.
[0018] Further, in another preferable embodiment, the valve body is
partitioned into an axis portion and an enlarged portion, and the
valve seat of the valve main body is provided with a plurality of
bleed notches.
[0019] According to a third aspect of the present invention, there
is provided a pressure control valve which is adapted to be
integrated into a steam-compression type refrigerating cycle which
is constituted fundamentally by: a compressor for circulating CO2
employed as a refrigerant, a gas cooler for cooling the refrigerant
that has been compressed by the compressor, an evaporator into
which the refrigerant is designed to be introduced from the gas
cooler, and an internal heat exchanger for performing heat exchange
between the refrigerant on the outlet side of the evaporator and
the refrigerant on the outlet side of the gas cooler; the pressure
control valve being constructed to pass the refrigerant to the
evaporator after adjusting, depending on the temperature of the
refrigerant on the outlet side of the gas cooler, the pressure of
the refrigerant that has been introduced therein via the internal
heat exchanger from the gas cooler.
[0020] This pressure control valve includes a temperature-sensing
inlet port for introducing therein the refrigerant from the gas
cooler; a temperature-sensing outlet port for sending the
refrigerant to the internal heat exchanger; a temperature-sensing
introduction chamber interposed between the temperature-sensing
inlet port and the temperature-sensing outlet port; a
temperature-sensing pressure responding element including a
temperature-sensing chamber for sensing the temperature of the
refrigerant that has been introduced into the temperature-sensing
introduction chamber, the temperature-sensing pressure responding
element being further capable of driving a valve body into a closed
or open state in response to fluctuations of inner pressure of the
temperature-sensing chamber; and a valve main body to which the
temperature-sensing pressure responding element can be integrally
attached; wherein the temperature-sensing chamber is filled with
CO2 at a predetermined density and also with a bulking quantity of
an inert gas, thereby enabling to adjust the pressure of
refrigerant on the outlet side of the gas cooler in order to secure
a maximum coefficient of performance relative to the temperature of
refrigerant on the outlet side of the gas cooler.
[0021] Preferably, the valve main body is formed of a solid body
which is cut out from an extruded rod having a +-shaped or
rectangular cross-section and provided with the aforementioned
temperature-sensing inlet port, the aforementioned
temperature-sensing outlet port, the aforementioned
temperature-sensing introduction chamber, the aforementioned
pressure-adjusting inlet port, the aforementioned
pressure-adjusting outlet port, a mounting portion for the pressure
responding element, and a valve seat portion for removably
receiving the valve body.
[0022] In a further preferable embodiment, a guide hole for
enabling the valve body to be slidably inserted therein is provided
over the valve seat of the valve main body, wherein the
aforementioned temperature-sensing inlet port, temperature-sensing
outlet port and temperature-sensing introduction chamber are
disposed over the guide hole, and the aforementioned
pressure-adjusting inlet port, pressure-adjusting outlet port and a
valve chamber are disposed below the guide hole.
[0023] In a preferable embodiment, the valve main body is provided
with at least one engaging portion selected from an external thread
portion, a flange portion, an internal thread portion for receiving
bolts, and an insertion hole for attaching the valve main body to
the gas cooler, to a pipe coupler for connection with the
evaporator, or to the internal heat exchanger.
[0024] Preferably, the temperature-sensing pressure responding
element is constituted by a diaphragm; a cap member having an
inverted U-shaped cross-section for partitioning, in cooperation
with the diaphragm, the temperature-sensing chamber; and a
cylindrical cap-receiving member for holding, in cooperation with
the cap member, an outer circumferential portion of the diaphragm
to hermetically seal the pressure responding element, the
cylindrical cap-receiving member including a flange portion for
enabling the valve body to be inserted therein through the inner
periphery thereof; wherein the cap-receiving member is additionally
provided on an outer circumferential wall of the cylindrical
portion thereof with an external thread for attaching the pressure
responding element to the valve main body.
[0025] In a further preferable embodiment, the valve body and the
diaphragm are disposed coaxially and one end portion of the valve
body is bonded to the diaphragm by means of projection welding.
[0026] In a still further preferable embodiment, the valve body is
consisted of a columnar valve rod, and a valve body portion formed
at a lower end portion of the valve rod, wherein the valve rod is
composed of a shaft portion, and an enlarged portion which is
formed integral with or fixedly secured to an upper portion of the
shaft portion. The aforementioned diaphragm is coupled to an upper
surface of the enlarged portion.
[0027] In another preferable embodiment, the temperature-sensing
introduction chamber is formed between the valve rod and the
cylindrical portion of the cap-receiving member.
[0028] In a further preferable embodiment, the valve body is
provided with a longitudinal hole having an open top, and the
diaphragm is provided with a through-hole for enabling the
temperature-sensing chamber to the longitudinal hole, thereby
constituting one extended temperature-sensing chamber consisting of
the temperature-sensing chamber and the longitudinal hole.
[0029] In a still further preferable embodiment, the diaphragm is
formed of a closed-end shortened cylindrical body, and the outer
edge portion and cylindrical portion of the diaphragm are held
between the cap member and the cap-receiving member to hermetically
seal the pressure responding element, wherein the lower end portion
of this laminated portion is welded to each other throughout the
entire periphery thereof.
[0030] In a still further preferable embodiment, the valve body is
provided, along the whole length of the circumferential wall
thereof, with a trench for interrupting heat transmission between
the temperature-sensing inlet port and the temperature-sensing
outlet port, and between the pressure-adjusting inlet port and the
pressure-adjusting outlet port. The valve seat of the valve main
body is provided with a plurality of bleed notches, and the valve
rod of the valve body is provided with a plurality of annular
trenches.
[0031] The pressure control valve according to the present
invention is featured in that the sensing of the temperature of the
refrigerant on the outlet side of gas cooler is performed not
through the introduction of the refrigerant into the valve main
body as conventionally executed, but through the provision of a
temperature-sensing cylinder or through the positioning of the
pressure control valve itself at the gas cooler (or in the vicinity
of the outlet port thereof); that the temperature-sensing pressure
responding element is not integrated into the valve main body but
is externally attached to the valve main body by means of screwing,
etc.; and that since the temperature-sensing cylinder and the
temperature-sensing chamber are filled with CO2 at a predetermined
density and also with a bulking quantity of an inert gas, thereby
enabling to adjust the pressure of refrigerant on the outlet side
of the gas cooler so as to secure a maximum coefficient of
performance relative to the temperature of refrigerant on the
outlet side of the gas cooler, thereby making it possible to adjust
the opening degree of valve by making use of only the
temperature-sensing pressure responding element without
necessitating the employment of a spring member, it is no longer
necessary to arrange a temperature-sensing inlet port, a
temperature-sensing outlet port, or a spring member. As a result,
the pressure of refrigerant on the outlet side of gas cooler can be
appropriately adjusted in conformity with the temperature of the
refrigerant on the outlet side of gas cooler, thus effectively
realizing the simplification of the structure thereof, the
reduction of the number of parts, and the reduction of the working
and assembling cost.
[0032] Further, according to the pressure control valve of the
present invention, since it is possible to adjust the opening
degree of valve by making use of only the temperature-sensing
pressure responding element, it is possible to simplify the
structure of pressure control valve and to reduce the number of
parts as compared with the conventional pressure control valve
where the opening degree of valve (the lifting quantity of the
valve body) is determined by a balance between the valve-opening
force originating from a pressure difference between the inside and
outside of the temperature-sensing chamber and the valve-closing
force by the spring member. Further, the pressure control valve of
the present invention is also featured in that the
temperature-sensing pressure responding element is not integrated
into the valve main body but is externally attached to the valve
main body by means of screwing, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a longitudinal sectional view illustrating a first
embodiment of the pressure control valve according to the present
invention;
[0034] FIG. 2 is a flow chart illustrating one example of a
steam-compression type refrigerating cycle where the pressure
control valve according to the first embodiment is installed;
[0035] FIG. 3 is an enlarged cross-sectional view illustrating a
coupled state between a diaphragm and a valve body;
[0036] FIGS. 4(A) to 4(C) are enlarged cross-sectional views each
illustrating an example of the restraining spring for
vibration;
[0037] FIG. 5 is a longitudinal sectional view illustrating a
second embodiment of the pressure control valve according to the
present invention;
[0038] FIG. 6 is a longitudinal sectional view illustrating a third
embodiment of the pressure control valve according to the present
invention;
[0039] FIG. 7 is a plan view illustrating a fourth embodiment of
the pressure control valve according to the present invention;
[0040] FIG. 8 is a right side view illustrating a fourth embodiment
of the pressure control valve according to the present
invention;
[0041] FIG. 9 is a flow chart illustrating one example of a
steam-compression type refrigerating cycle where the pressure
control valve according to the fourth embodiment is installed;
[0042] FIGS. 10(A) and 10(B) are partially cut views each
illustrating a technique of enhancing the temperature sensitivity
of temperature-sensing chamber;
[0043] FIG. 11 is a longitudinal sectional view illustrating a
fifth embodiment of the pressure control valve according to the
present invention;
[0044] FIG. 12 is a plan view of the pressure control valve shown
in FIG. 11;
[0045] FIG. 13 is a left side view of the pressure control valve
shown in FIG. 11;
[0046] FIG. 14 is a flow chart illustrating one example of a
steam-compression type refrigerating cycle where the pressure
control valve according to the fifth embodiment is installed;
[0047] FIG. 15 is an enlarged cross-sectional view illustrating a
coupled state between a diaphragm and a valve body;
[0048] FIG. 16 is a longitudinal sectional view illustrating a
sixth embodiment of the pressure control valve according to the
present invention;
[0049] FIG. 17 is a plan view of the pressure control valve shown
in FIG. 16;
[0050] FIG. 18 is a longitudinal sectional view illustrating a
seventh embodiment of the pressure control valve according to the
present invention;
[0051] FIG. 19 is a longitudinal sectional view illustrating an
eighth embodiment of the pressure control valve according to the
present invention;
[0052] FIG. 20 is a left side view of the pressure control valve
shown in FIG. 19; and
[0053] FIG. 21 is a flow chart illustrating one example of a
steam-compression type refrigerating cycle where the pressure
control valve of the prior art is installed.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS
[0054] Next, various embodiments of the pressure control valve
according to the present invention will be explained in detail with
reference to the drawings.
[0055] FIG. 1 shows a longitudinal sectional view illustrating a
first embodiment of the pressure control valve according to the
present invention. The pressure control valve 1A according to the
first embodiment shown herein is adapted to be integrated into a
steam-compression type refrigerating cycle 100A which is
fundamentally constructed in the same manner as shown in FIG. 11
mentioned above, wherein the refrigerant to be introduced into the
pressure control valve 1A from a gas cooler 102 through an internal
heat exchanger 103 is enabled to enter into an evaporator 104 after
being adjusted in pressure depending on the temperature of
refrigerant on the outlet side of the gas cooler 102 as shown in
FIG. 2. Additionally, in the refrigerating cycle 100A shown in FIG.
2, the portions or members constructed or functioning in the same
manner as those of the refrigerating cycle 100 shown in FIG. 11
will be identified by the same reference numerals, thereby omitting
the explanations thereof.
[0056] The pressure control valve 1A is provided for effectively
operating the refrigerating cycle 100A. In other words, the
pressure control valve 1A is provided for adjusting the pressure of
the refrigerant on the outlet side of the gas cooler 102 so as to
secure a maximum coefficient of performance relative to the
temperature of refrigerant on the outlet side of the gas cooler
102. This pressure control valve 1A is constituted by a valve main
body 10A, a valve body 15 consisting of a valve rod 15A and a valve
body portion 15B having a truncated cone-like configuration and
formed at a lower end portion of the valve rod 15A, a
temperature-sensing pressure responding element 20, and a
temperature-sensing cylinder 30 made of a metal excellent in heat
conductivity for sensing the temperature of refrigerant on the
outlet side of the gas cooler 102, the opposite ends of the
cylinder 30 being tapered into a cone-like configuration.
[0057] The valve main body 10A is provided with a
pressure-adjusting inlet port (coupler) 11 which is opened in a
sidewall of the valve main body 10A and communicates with an inlet
passageway 11a for introducing a refrigerant therein from the gas
cooler 102 through the internal heat exchanger 103; a
pressure-adjusting outlet port (coupler) 12 which is opened
opposite to the aforementioned inlet port 11 and communicates with
an outlet passageway 12a for discharging the refrigerant therefrom
to the evaporator 104 after adjusting the pressure of refrigerator
in conformity with the temperature of refrigerant on the outlet
side of the gas cooler 102; a valve seat 13 mounted on an upper end
portion of the outlet passageway 12a and having a truncated
cone-like configuration for removably receiving the valve body 15
(the valve body portion 15B thereof); a valve chamber 14 defined
over this valve seat 13; and an internal thread portion 10b for
attaching the temperature-sensing pressure responding element 20 to
the valve main body 10A. Additionally, the valve seat 13 is
provided with a small bleed notch (not shown), so that the opening
degree of the pressure control valve corresponds to a quantity of
lift from the valve seat 13 of valve body 15 (the valve body
portion 15B thereof). Since the valve seat 13 is formed through
notch-forming using a press, the working of the outlet passageway
12a would become easier and, at the same time, it is possible to
obtain a self-cleaning effect during the operation of the control
valve.
[0058] The temperature-sensing pressure responding element 20 is
constituted by a closed-end short cylindrical diaphragm 21; a cap
member 22 having an inverted U-shaped cross-section for
partitioning, in cooperation with the diaphragm 21, the
temperature-sensing chamber (diaphragm chamber) 25; and a
cylindrical cap-receiving member 23 for holding, in cooperation
with the cap member 22, an outer circumferential portion of the
diaphragm 21 (an outer circumferential edge portion and a
cylindrical portion) to hermetically seal the pressure responding
element 20. The cylindrical cap-receiving member 23 includes a
flange portion 23a for enabling the valve body 15 to be slidably
inserted therein. A lower end portion of the superimposed portion
(sandwiched portion) of the cap member 22, cap-receiving member 23
(the flange portion 23a thereof) and the diaphragm 21 are bonded to
each other by means of welding (a welded portion Ka). At a lower
portion of the cap-receiving member 23, there is provided a thin
constricted portion 23c for defining the valve chamber 24, and this
thin constricted portion 23c is provided with a through-hole 23e
constituting an inlet passageway 11a.
[0059] A diametrally enlarged portion 15a is formed on the top of
the valve rod 15A of valve body 15 and is enabled to move up and
down in a recessed portion 23d formed at an upper central portion
of the cap-receiving member 23. On a central portion of the upper
surface of the diametrally enlarged portion 15a, there are formed
an annular ridge 16 having a trapezoidal cross-section as shown in
FIG. 3 and a pair of annular trenches 16a and 16b located on the
opposite sides of the annular ridge 16. The diaphragm 21 is bonded
to this annular ridge 16 by means of projection welding (a welded
portion Kb), thus positioning the diaphragm 21 coaxial with the
valve body 15 (a common axial line Ox).
[0060] The cap-receiving member 23 is provided, on an outer
circumferential wall of the cylindrical portion thereof, with an
external thread portion 23b which is adapted to be engaged with the
internal thread portion 10b for attaching the pressure responding
element to the valve main body 10A. The unit consisting of the
valve body 15 and the temperature-sensing pressure responding
element 20 which are integrally bonded as described above is
mounted on the valve main body 10A in such a manner that, under the
condition where a restraining spring 18 for vibration (to be
discussed hereinafter) is disposed in the vicinity of a lower end
portion of the valve rod 15A, the external thread portion 23b is
engaged with the internal thread portion 10b of valve main body 10A
and, at the same time, the unit is rotated entirely, thus mounting
the unit on the valve main body 10A. Additionally, a gasket 26 is
interposed between the lower surface of the cap-receiving member 23
and the upper surface of the valve main body 10A.
[0061] Meanwhile, the restraining spring 18 for suppressing the
vibration of the valve body 15 is disposed at the bottom of the
valve chamber 14 of valve main body 10A. As shown in FIGS. 4(A) and
4(b), this restraining spring 18 for vibration is formed of an
elastic plate and constituted by a generally annular (having a
plurality (eight in this embodiment) of teeth 18a externally
extending and spaced apart from each other at equal angular
intervals) bottom portion 18A having an inverted V-shaped
configuration which is designed to be flattened as it is pressed
onto the valve main body 10A by the thin constricted portion 23c on
the occasion of mounting (through screwing) the cap-receiving
member 23 on the valve main body 10A, and a plurality (four in this
embodiment) of tongue-shaped flexible flaps 18B spaced apart from
each other at equal angular intervals (symmetrical in every
directions). Additionally, a distal end portion of each of the
tongue-shaped flexible flaps 18B is bent toward the outer
circumferential wall of the valve body 15 so as to facilitate
mounting thereof on the valve rod 15A. Further, the restraining
spring 18 for vibration shown in FIGS. 4(A) and 4(b) is configured
so as to enable the inner circumferential portion and outer
circumferential portion of the bottom portion 18A to contact with
the valve main body 10A from the beginning. However, it is also
possible to employ restraining spring 18' for vibration which is
designed such that only the outer circumferential portion of the
bottom portion 18A is permitted to contact with the valve main body
10A at first without the inner circumferential portion thereof
being permitted to contact with the valve main body 10A at first as
shown in FIG. 4(C).
[0062] In this embodiment, in order to detect the temperature of
refrigerant on the outlet side of gas cooler 102, the
temperature-sensing cylinder 30 is disposed in contact with an
upstream end portion (in the vicinity of the outlet port 102b of
gas cooler 102) of a conduit defining a channel 122 between the gas
cooler 102 and the internal heat exchanger 103 as shown in FIG. 2
and fixed to this upstream end portion by means of a suitable
fastener. Further, the temperature-sensing cylinder 30 communicates
via a capillary tube 32 with the temperature-sensing chamber 25.
One end of the capillary tube 32 is hermetically connected with the
temperature-sensing cylinder 30 and the other end thereof is
hermetically connected with the temperature-sensing chamber 25. The
temperature-sensing cylinder 30 and the temperature-sensing chamber
25 are charged, through a short capillary tube 34 connected with
the other end of the temperature-sensing cylinder 30, with CO2 at a
predetermined density and also with a bulking quantity of an inert
gas, thereby enabling to adjust the pressure of refrigerant on the
outlet side of the gas cooler 102 in order to secure a maximum
coefficient of performance relative to the temperature of
refrigerant on the outlet side of the gas cooler 102 (For example,
under the condition where the temperature of the refrigerant on the
outlet side is 40.degree. C., when the coefficient of performance
can be made maximum if the pressure of the refrigerant on the
outlet side is set to 10 MPa, it is controlled so that the pressure
of the refrigerant on the outlet side may become 10 MPa). Under
this condition, the distal end of the capillary tube 34 is
sealed.
[0063] In this structure as described above, the temperature
(fluctuation thereof) of refrigerant on the outlet side of the gas
cooler 102 is detected by the temperature-sensing cylinder 30 and
the temperature (fluctuation thereof) thus detected is transmitted
via the capillary tube 32 to the temperature-sensing chamber 25,
thereby rendering the inner pressure (fluctuation thereof) of the
temperature-sensing chamber 25 to conform with the temperature
(fluctuation thereof) of refrigerant on the outlet side of the gas
cooler 102. As a result, the diaphragm 21 is actuated in response
to the inner pressure (fluctuation thereof) of the
temperature-sensing chamber 25, thereby driving the valve body 15
in an opening or closing direction to adjust the opening degree of
valve, thus adjusting the pressure of refrigerant on the outlet
side of the gas cooler 102 so as to secure a maximum coefficient of
performance relative to the temperature of refrigerant on the
outlet side of the gas cooler 102.
[0064] As explained above, the pressure control valve 1A according
to this embodiment is featured in that the sensing of the
temperature of the refrigerant on the outlet side of gas cooler 102
is performed not through the introduction of the refrigerant into
the valve main body 10A as conventionally executed, but through the
provision of a temperature-sensing cylinder 30; that the
temperature-sensing pressure responding element 20 is not
integrated into the valve main body 10A but is externally attached
to the valve main body 10A by means of screwing, etc.; and that
since the temperature-sensing cylinder 30 and the
temperature-sensing chamber 25 are filled with CO2 at a
predetermined density and also with a bulking quantity of an inert
gas, thereby enabling to adjust the pressure of refrigerant on the
outlet side of the gas cooler 102 so as to secure a maximum
coefficient of performance relative to the temperature of
refrigerant on the outlet side of the gas cooler 102, thereby
making it possible to adjust the opening degree of valve by making
use of only the temperature-sensing pressure responding element 20
without necessitating the employment of a spring member, it is no
longer necessary to arrange a temperature-sensing inlet port, a
temperature-sensing outlet port, or a spring member. As a result,
the pressure of refrigerant on the outlet side of gas cooler 102
can be appropriately adjusted in conformity with the temperature of
the refrigerant on the outlet side of gas cooler, thus effectively
realizing the simplification of the structure thereof, the
reduction of the number of parts, and the reduction of the working
and assembling cost.
[0065] FIG. 5 shows a longitudinal sectional view illustrating a
second embodiment of the pressure control valve according to the
present invention. The pressure control valve 1B according to the
second embodiment shown herein is fundamentally the same in
construction as that of the pressure control valve 1A of the first
embodiment (the portions or members constructed or functioning in
the same manner as those of the pressure control valve 1A of the
first embodiment will be identified by the same reference numerals,
thereby omitting the explanations thereof). In the pressure control
valve 1B of this embodiment however, a valve main body 10B is
disposed in a valve-mounting portion 130 of the heat exchanger 103,
thereby enabling the pressure control valve 1B to be easily
attached to the internal heat exchanger 103 or to the gas cooler
102 and also making it unnecessary to connect the pressure control
valve 1B with a conduit and the like for forming a channel.
[0066] Namely, the valve main body 10B is formed of a cylindrical
configuration having a closed bottom and a step portion. This valve
main body 10B is also provided, on the outer circumferential wall
thereof, with an external thread portion 19 to be engaged with the
internal thread portion 135 of the valve-mounting portion 130 which
is formed in the internal heat exchanger 103 in advance. Further, a
pair of right and left pressure-adjusting inlet ports 11 are formed
at a lower wall portion of the valve main body 10B, these inlet
ports 11 being directed downward obliquely. Additionally, a
pressure-adjusting outlet port 12 is formed at a central portion of
the bottom of valve main body 10B. An O-ring 41 for sealing an
interface between the valve main body 10B and the valve-mounting
portion 130 is mounted at an upper portion of the valve main body
10B. Furthermore, the valve main body 10B is also provided, at an
outer peripheral portion of the underside of the valve main body
10B, with an annular ridge 42 having a triangular or trapezoidal
cross-section for preventing a refrigerant from flowing through an
interface between the inlet ports 11 and the pressure-adjusting
outlet port 12.
[0067] The pressure control valve 1B thus constructed can be
mounted on the valve-mounting portion 130 by engaging the external
thread portion 19 thereof with the internal thread portion 135 of
the valve-mounting portion 130 and, at the same time, by rotating
it entirely. On this occasion, the annular ridge 42 provided on the
underside of the valve main body 10B is pressed against the bottom
surface of the valve-mounting portion 130 to shield an interface
between the inlet ports 11 and the pressure-adjusting outlet port
12.
[0068] In this embodiment, the refrigerant from the gas cooler 102
is permitted to flow from an inlet channel 136 provided at a lower
portion of the valve-mounting portion 130 after passing through the
internal heat exchanger 103 into the inlet ports 11 through a space
formed between the lower outer wall of the valve main body 10B (a
wall portion outer than the annular ridge 42) and the inner
circumferential wall of the valve-mounting portion 130. Thereafter,
the refrigerant is permitted to enter into the valve chamber 14
and, while being reduced in pressure depending on the opening
degree of valve, discharged from the valve chamber 14 to the
pressure-adjusting outlet port 12. Then, the refrigerant is
delivered, through an outlet channel 137 provided at a lower
portion of the valve-mounting portion 130, to the evaporator
104.
[0069] FIG. 6 shows a longitudinal sectional view illustrating a
third embodiment of the pressure control valve according to the
present invention. The pressure control valve 1C according to the
third embodiment shown herein is fundamentally the same in
construction as that of the pressure control valve 1A of the first
embodiment (the portions or members constructed or functioning in
the same manner as those of the pressure control valve 1A of the
first embodiment will be identified by the same reference numerals,
thereby omitting the explanations thereof).
[0070] While the first embodiment shown in FIG. 1 illustrates an
example wherein the valve main body 10A is constructed such that
the conduit extending from the internal heat exchanger 103 and the
conduit extending to the evaporator 104 are both arranged
horizontally, the valve main body 10C of the third embodiment shown
in FIG. 6 is constructed such that the conduit extending to the
evaporator 104 is disposed perpendicular to the conduit extending
from the internal heat exchanger 103. Therefore, by exchanging the
valve main body 10C of the third embodiment for the valve main body
10A of the first embodiment in assembling the pressure control
valve, it is possible to provide a pressure control valve which is
capable of coping with either the horizontal conduit or the
vertical conduit. In the pressure control valve 1C according to the
third embodiment, the cap-receiving member 23 is formed of two
parts, i.e. a step-attached cylindrical portion 23A having an
external thread portion 23b, and an annular flange portion 23B
formed of plate material and having an inverted U-shaped
cross-section. Further, the valve rod 15A is partitioned into a
shaft portion 15A' and a diametrally enlarged portion 15a having a
T-shaped cross-section. When partitioned in this manner, only the
diametrally enlarged portion 15a can be made of SUS304 and the
shaft portion 15A' may be formed of SUS303, which is advantageous
in terms of working cost.
[0071] Since it is difficult to manufacture the step-attached
cylindrical portion 23A of the cap-receiving member 23 where the
external thread portion 23b by means of press-working, it will be
manufactured by way of cutting work. The annular flange portion 23B
can be manufactured by means of press-working which can be
performed at a relatively low cost. In this case, an upper enlarged
portion 23g of the step-attached cylindrical portion 23A is
press-inserted into a stepped inner circumferential portion of the
annular flange portion 23B to form an assembled body, to which the
valve rod 15A (where the shaft portion and the diametrally enlarged
portion are integrated through press-insertion) which is integrated
with the diaphragm 21, and the cap member 22 are successively
secured in the mentioned order by means of projection welding.
Thereafter, the cap-receiving member 23, the diaphragm 21 and the
cap member 22 are integrally welded along the entire peripheral
portion Ka thereof. The attachment of the temperature-sensing
pressure responding element 20 to the valve main body 10C can be as
follows. Namely, the annular flange portion 23B is fitted in an
annular ridge portion 10f projected on the upper surface of the
valve main body 10C, and, at the same time, the external thread
portion 23b is engaged with the internal thread portion 10b of the
valve main body 10C and the temperature-sensing pressure responding
element 20 is entirely rotated and screwed down, thereby securing
the temperature-sensing pressure responding element 20 to the valve
main body 1C. Additionally, a gasket 46 is interposed between the
upper surface of the annular ridge portion 10f of valve main body
10C and the recessed portion of the annular flange portion 23B.
Since the cap-receiving member 23 is partitioned into two members
and one of which is manufactured by means of press working which
can be performed at a relatively low cost, it is possible to reduce
the manufacturing cost of parts.
[0072] Further, a short shaft portion of the diametrally enlarged
portion 15a having a T-shaped cross-section is integrally secured
to an upper portion of the shaft portion 15A' of valve rod 15A by
means of press-insertion, etc. Since the valve rod 15A is
partitioned into the shaft portion 15A' and the diametrally
enlarged portion 15a as described above, the formation of the
annular ridge portion 16 to be utilized in the bonding thereof to
the diaphragm 21 by means of projection welding can be
facilitated.
[0073] FIG. 7 is a plan view illustrating a fourth embodiment of
the pressure control valve according to the present invention, and
FIG. 8 is a right side view thereof. The pressure control valve 1D
according to the fourth embodiment shown herein is fundamentally
the same in construction as that of the pressure control valve 1A
of the first embodiment, except that the temperature-sensing
cylinder 30 is not provided therein. Therefore, the details on the
internal constituent components should be referred to the
description of the first embodiment.
[0074] As shown in FIG. 9, the pressure control valve 1D according
to the fourth embodiment is adapted to be mounted on the gas cooler
102 of a steam-compression type refrigerating cycle 100B which is
fundamentally constructed in the same manner as shown FIG. 2,
wherein the refrigerant to be introduced into the pressure control
valve 1D from a gas cooler 102 through an internal heat exchanger
103 is enabled to enter into an evaporator 104 after being adjusted
in pressure depending on the temperature of refrigerant on the
outlet side of the gas cooler 102.
[0075] More specifically, the pressure control valve 1D (the
temperature-sensing chamber 25 thereof) is arranged in front of the
gas cooler 102 for example as shown in FIG. 9 so as to directly
detect the temperature of refrigerant on the outlet side of gas
cooler 102.
[0076] Further, the temperature-sensing chamber 25 of the
temperature-sensing pressure responding element 20 is charged,
through a short capillary tube 39 secured to the
temperature-sensing chamber 25, with CO2 at a predetermined density
and also with a bulking quantity of an inert gas, thereby enabling
to adjust the pressure of refrigerant on the outlet side of the gas
cooler 102 in order to secure a maximum coefficient of performance
relative to the temperature of refrigerant on the outlet side of
the gas cooler 102 (For example, under the condition where the
temperature of the refrigerant on the outlet side is 40.degree. C.,
when the coefficient of performance can be made maximum if the
pressure of the refrigerant on the outlet side is set to 10 MPa, it
is controlled so that the pressure of the refrigerant on the outlet
side may become 10 MPa). Under this condition, the distal end of
the capillary tube 39 is sealed.
[0077] In this structure as described above, the temperature of
refrigerant on the outlet side of the gas cooler 102 is detected by
the temperature-sensing chamber 25, thereby rendering the inner
pressure of the temperature-sensing chamber 25 to conform with the
temperature of refrigerant on the outlet side of the gas cooler
102. As a result, the diaphragm 21 is actuated in response to the
fluctuation of inner pressure of the temperature-sensing chamber
25, thereby driving the valve body 15 in an opening or closing
direction to adjust the opening degree of valve, thus adjusting the
pressure of refrigerant on the outlet side of the gas cooler 102 so
as to secure a maximum coefficient of performance relative to the
temperature of refrigerant on the outlet side of the gas cooler
102.
[0078] As explained above, the pressure control valve 1D according
to this embodiment is featured in that the sensing of the
temperature of the refrigerant on the outlet side of gas cooler 102
is performed not through the introduction of the refrigerant into
the valve main body 10A as conventionally executed, but through the
positioning of the pressure control valve 1D itself in front of the
gas cooler 102; that the temperature-sensing pressure responding
element 20 is not integrated into the valve main body 10D but is
externally attached to the valve main body 10D by means of
screwing, etc. as in the case of the first embodiment; and that
since the temperature-sensing chamber 25 is filled with CO2 at a
predetermined density and also with a bulking quantity of an inert
gas, thereby enabling to adjust the pressure of refrigerant on the
outlet side of the gas cooler 102 so as to secure a maximum
coefficient of performance relative to the temperature of
refrigerant on the outlet side of the gas cooler 102, thereby
making it possible to adjust the opening degree of valve by making
use of only the temperature-sensing pressure responding element 20
without necessitating the employment of a spring member, it is no
longer necessary to arrange a temperature-sensing inlet port, a
temperature-sensing outlet port, or a spring member. As a result,
the pressure of refrigerant on the outlet side of gas cooler 102
can be appropriately adjusted in conformity with the temperature of
the refrigerant on the outlet side of gas cooler, thus effectively
realizing the simplification of the structure thereof, the
reduction of the number of parts, and the reduction of the working
and assembling cost.
[0079] Additionally, in the cases of the pressure control valves
1A, 1C and 1D according to the aforementioned first, third and
fourth embodiments, the valve main bodies 10A, 10C and 10D are
respectively formed of an approximately rectangular parallelepiped
body which is cut out from an extruded aluminum rod having a
rectangular cross-section and provided with a refrigerant inlet
port 11, with a refrigerant outlet port 12, with a mounting portion
(internal thread portion 10b) for the pressure responding element,
with internal thread portions 51 and 52 to be used for attaching
the pressure control valves 1A, 1C and 1D to a conduit member or
the internal heat exchanger 103, and with a valve seat portion. As
a result, it is possible to further simplify the structure the
pressure control valve, to reduce the number of parts, and save the
working and assembling cost.
[0080] Furthermore, in order to enhance the temperature sensitivity
of the temperature-sensing chamber 25, it is preferable to provide
the temperature-sensing chamber 25 with a plurality of
temperature-sensing fins or to attach a cylindrical body or
cap-like body having temperature-sensing fins to the outer
circumferential wall of the temperature-sensing chamber 25.
[0081] FIGS. 11, 12 and 13 are a cross-sectional view, a plan view
and a left side view of the pressure control valve, respectively,
all illustrating a fifth embodiment of the present invention. As
shown in FIG. 14, the pressure control valve 1E according to the
fifth embodiment shown herein is adapted to be integrated into a
steam-compression type refrigerating cycle 100C which is
fundamentally constructed in the same manner as shown FIG. 21
mentioned above, wherein the refrigerant to be introduced into the
pressure control valve 1E from a gas cooler 102 through an internal
heat exchanger 103 is enabled to enter into an evaporator 104 after
being adjusted in pressure depending on the temperature of
refrigerant on the outlet side of the gas cooler 102. Additionally,
in the refrigerating cycle 100C shown in FIG. 14, the portions or
members constructed or functioning in the same manner as those of
the refrigerating cycle 100 shown FIG. 21 will be identified by the
same reference numerals, thereby omitting the explanations
thereof.
[0082] The pressure control valve 1E is provided for effectively
operating the refrigerating cycle 100C. In other words, the
pressure control valve 1E is provided for adjusting the pressure of
the refrigerant on the outlet side of the gas cooler 102 so as to
secure a maximum coefficient of performance relative to the
temperature of refrigerant on the outlet side of the gas cooler
102. This pressure control valve 1E is constituted by a valve main
body 10A, a valve body 15 consisting of a valve rod 15A and a valve
body portion 15B having a truncated cone-like configuration and
formed at a lower end portion of the valve rod 15A, and a
temperature-sensing pressure responding element 20.
[0083] The valve main body 10E is formed of a solid body which is
cut out from an extruded aluminum rod having a +-shaped
cross-section (see FIG. 13) and provided with the following
constituent components which are formed through cutting work.
Namely, this valve main body 10E is provided, at a lower portion
thereof, with a pressure-adjusting inlet port (coupler) 11 which is
opened in a right sidewall of the valve main body 10E and
communicates with an inlet passageway 11a for introducing a
refrigerant therein from the gas cooler 102 through the internal
heat exchanger 103, a valve chamber 14 into which a refrigerant is
introduced from the pressure-adjusting inlet port 11, a valve seat
13 defining the bottom of the valve chamber 14 and having a
truncated cone-like configuration for removably receiving the valve
body 15 (the valve body portion 15B thereof), and a
pressure-adjusting outlet port (coupler) 12 which is opened in a
left sidewall of the valve main body 10E and communicates with an
outlet passageway 12a for delivering the refrigerant from the valve
chamber 14 to the evaporator 104. Additionally, the valve seat 13
is provided with a small bleed notch (not shown), so that the
opening degree of the pressure control valve 1E corresponds to a
quantity of lift from the valve seat 13 of valve body 15 (the valve
body portion 15B thereof). Since the valve seat 13 is formed
through notch-forming using a press, the working of the outlet
passageway 12a would become easier and, at the same time, it is
possible to obtain a self-cleaning effect during the operation of
the control valve.
[0084] A guide hole 18a communicating with the valve chamber 14 is
formed at a central portion of the valve main body 10E, thus
enabling the valve rod 15A (an intermediate diametrally enlarged
portion 15c thereof) to be slidably inserted into the guide hole
18a. Above this guide hole 18a, i.e. at an upper portion of the
valve main body 10E, there are formed a temperature-sensing inlet
port 61 which is opened on the left side of the valve main body 10E
for introducing a refrigerant therein from the gas cooler 102, and
a temperature-sensing outlet port 62 which is opened on the right
side of the valve main body 10E for delivering the refrigerant to
the internal heat exchanger 103. A temperature-sensing introduction
chamber 60 is formed between the temperature-sensing inlet port 61
and the temperature-sensing outlet port 62. An internal thread
portion 10b for attaching the temperature-sensing pressure
responding element 20 to the valve main body 10E, as described
hereinafter, is formed on an upper circumferential wall of the
valve main body 10E. Additionally, an O-ring 48 for preventing the
flow of refrigerant between the valve chamber 14 and the
temperature-sensing introduction chamber 60 is mounted on the
intermediate diametrally enlarged portion 15c of valve rod 15.
Further, the temperature-sensing outlet port 62 is offset back and
forth relative to the temperature-sensing inlet port 61.
[0085] The temperature-sensing pressure responding element 20 is
constituted by a closed-end short cylindrical diaphragm 21; a cap
member 22 having an inverted U-shaped cross-section for
partitioning, in cooperation with the diaphragm 21, the
temperature-sensing chamber (diaphragm chamber) 25; and a
cylindrical cap-receiving member 23 for holding, in cooperation
with the cap member 22, an outer circumferential portion of the
diaphragm 21 (an outer circumferential edge portion and a
cylindrical portion) to hermetically seal the pressure responding
element 20, the cylindrical cap-receiving member 23 including a
flange portion 23a for enabling the valve body 15 to be slidably
inserted therein. A lower end portion of the superimposed portion
(sandwiched portion) of the cap member 22, cap-receiving member 23
(the flange portion 23a thereof) and the diaphragm 21 is entirely
bonded to each other by means of welding (a welded portion Ka).
[0086] The valve rod 15A of the valve body 15 is constituted by a
shaft portion 15a and a diametrally enlarged portion 15b having a
T-shaped cross-section. This diametrally enlarged portion 15b is
disposed in such a manner that the axis thereof is fixedly secured,
through press-insertion or welding, to a vertical hole formed on an
upper end portion of the shaft portion 15a, and the top portion
(disc portion) thereof is inserted, in a floating manner, in a
recessed portion 23d formed at an upper central portion of the
cap-receiving member 23, so that the top portion (disc portion)
thereof is enabled to move up and down in the recessed portion 23d.
On a central portion of the upper surface of the diametrally
enlarged portion 15b, there are formed an annular ridge 16 having a
trapezoidal cross-section as shown in FIG. 15 and a pair of annular
trenches 16a and 16b located on the opposite sides of the annular
ridge 16. To this annular ridge 16, the diaphragm 21 is bonded by
means of projection welding (a welded portion Kb), thus positioning
the diaphragm 21 coaxial with the valve body 15 (a common axial
line Ox).
[0087] Meanwhile, the temperature-sensing chamber 25 of the
temperature-sensing pressure responding element 20 is charged,
through a short capillary tube 39 secured to the
temperature-sensing chamber 25, with CO2 at a predetermined density
and also with a bulking quantity of an inert gas, thereby enabling
to adjust the pressure of refrigerant on the outlet side of the gas
cooler 102 in order to secure a maximum coefficient of performance
relative to the temperature of refrigerant on the outlet side of
the gas cooler 102 (For example, under the condition where the
temperature of the refrigerant on the outlet side is 40.degree. C.,
when the coefficient of performance can be made maximum if the
pressure of the refrigerant on the outlet side is set to 10 MPa, it
is controlled so that the pressure of the refrigerant on the outlet
side may become 10 MPa). Under this condition, the distal end of
the capillary tube 39 is sealed.
[0088] The cap-receiving member 23 is provided, on an outer
circumferential wall of the cylindrical portion thereof, with an
external thread portion 23b which is adapted to be engaged with the
internal thread portion 10b for attaching the pressure responding
element to the valve main body 10E. The unit consisting of the
valve body 15 and the temperature-sensing pressure responding
element 20 which are integrally bonded as described above is
mounted on the valve main body 10A in such a manner that the
external thread portion 23b is engaged with the internal thread
portion 10b of valve main body 10E and, at the same time, the unit
is rotated entirely, thus mounting the unit on the valve main body
10E. Under the condition where the unit is mounted on the valve
main body 10E, the temperature-sensing chamber 60 is formed between
the cap-receiving member 23 and an upper portion of the valve rod
15, thereby enabling the temperature of refrigerant in this
temperature-sensing chamber 60 to be detected by the
temperature-sensing chamber 25.
[0089] Additionally, a gasket 26 is interposed between the
underside of the cap-receiving member 23 and an upper surface of
the valve main body 10E. Further, on the right and left sidewalls
of the valve main body 10E, there are provided tapped holes 51 and
52 and circular holes 53 and 54 for mounting the pressure control
valve 1E on joint pipe couplers for the gas cooler 102 or the
evaporator 104, or on the internal heat exchanger 103.
[0090] In this structure as described above, when the refrigerant
on the outlet side of the gas cooler 102 is delivered from the
temperature-sensing inlet port 61 to the temperature-sensing
chamber 60, the temperature of refrigerant on the outlet side of
the gas cooler 102 is detected by the temperature-sensing chamber
25, thereby rendering the inner pressure of the temperature-sensing
chamber 25 to conform with the temperature of refrigerant on the
outlet side of the gas cooler 102. As a result, the diaphragm 21 is
actuated in response to the fluctuation of inner pressure of the
temperature-sensing chamber 25, thereby driving the valve body 15
in an opening or closing direction to adjust the opening degree of
valve, thus adjusting the pressure of refrigerant on the outlet
side of the gas cooler 102 so as to secure a maximum coefficient of
performance relative to the temperature of refrigerant on the
outlet side of the gas cooler 102.
[0091] As explained above, according to the pressure control valve
1E of this embodiment, since the opening degree of valve is
adjusted by means of only the temperature-sensing pressure
responding element 20, it is possible to simplify the structure of
the pressure control valve and to reduce the number of parts as
compared with the conventional pressure control valve wherein the
opening degree of valve (the lifting quantity of the valve body) is
determined by a balance between the valve-opening force originating
from a pressure difference between the inside and outside of the
temperature-sensing chamber and the valve-closing force by the
spring member. Further, since the temperature-sensing pressure
responding element is not integrated into the valve main body but
is externally attached to the valve main body by means of screwing,
etc., it is possible to effectively realize the simplification of
the structure thereof, the reduction of the number of parts, and
the reduction of the working and assembling cost.
[0092] FIGS. 16 and 17 are a longitudinal cross-sectional view and
a plan view of the pressure control valve, respectively, all
illustrating a sixth embodiment of the present invention. The
pressure control valve 1F according to the sixth embodiment shown
herein is fundamentally the same in construction as that of the
pressure control valve 1E of the fifth embodiment (the portions or
members constructed or functioning in the same manner as those of
the pressure control valve 1E of the fifth embodiment will be
identified by the same reference numerals, thereby omitting the
explanations thereof). In the pressure control valve 1F of this
embodiment however, it is designed such that the pressure control
valve 1F can be easily mounted on the heat exchanger 103 or the gas
cooler 102, and that it is no longer necessary to connect the
pressure control valve 1F with a conduit and the like for forming a
channel. Namely, the valve main body 10F is formed of a cylindrical
configuration having a closed bottom and a step portion. This valve
main body 10F is also provided, on the outer circumferential wall
thereof, with an external thread portion 19 to be engaged with the
internal thread portion 135 of the valve-mounting portion 130 which
is formed in the internal heat exchanger 103 in advance. Further, a
flange 70 hexagonal in plan view is attached to an upper edge
portion of the valve main body 10b. A couple of O-rings 71 and 72
are disposed respectively over and below the pressure-adjusting
inlet port 11 and the pressure-adjusting outlet port 12 which are
provided at a lower portion of the valve main body 10F.
[0093] The pressure control valve 1F thus constructed can be
mounted on the valve-mounting portion 130 by engaging the external
thread portion 19 thereof with the internal thread portion 135 of
the valve-mounting portion 130 and, at the same time, by rotating
it (the flange 70) entirely.
[0094] In this embodiment, the refrigerant for pressure control
which has been delivered from the gas cooler 102 is permitted to
flow from an inlet channel 136 provided at a lower portion of the
valve-mounting portion 130 to the valve chamber 14. Then, while
being reduced in pressure depending on the opening degree of valve,
the refrigerant is discharged from the valve chamber 14 and
delivered, through an outlet channel 137 provided at a lower
portion of the valve-mounting portion 130, to the evaporator
104.
[0095] Further, the refrigerant delivered from the gas cooler 102
is permitted to flow from an inlet channel 141 provided at an upper
portion of the valve-mounting portion 130 into a
temperature-sensing inlet port 61 of the valve main body 10 and, at
the same time, introduced into the temperature-sensing introduction
chamber 60, wherein the temperature of the refrigerant is detected
by the temperature-sensing chamber 25. Thereafter, the refrigerant
is delivered from a temperature-sensing outlet port 62 to the
internal heat exchanger 103 through an outlet channel 142 provided
at an upper portion of the valve-mounting portion 130.
[0096] FIG. 18 is a longitudinal cross-sectional view of the
pressure control valve illustrating a seventh embodiment of the
present invention. The pressure control valve 1G according to the
seventh embodiment shown herein is fundamentally the same in
construction as that of the pressure control valve 1E of the fifth
embodiment (the portions or members constructed or functioning in
the same manner as those of the pressure control valve 1E of the
fifth embodiment will be identified by the same reference numerals,
thereby omitting the explanations thereof). In the pressure control
valve 1G of this embodiment however, it is designed such that the
diametrally enlarged portion 15b is integrally attached to an upper
edge portion of the shaft portion 15a of valve rod 15A and, at the
same time, a vertical hole 19 having an open top is formed in the
shaft portion 15a, that a through-hole 21a interconnecting the
temperature-sensing chamber 25 with the vertical hole 19 is formed
at a central portion of the diaphragm 21, and that an expanded
temperature-sensing chamber is formed by a combination of the
temperature-sensing chamber 25 and the vertical hole 19.
[0097] Since the temperature-sensing chamber is expanded toward the
temperature-sensing introduction chamber 60, it is possible to
enhance the temperature-sensing capability of the
temperature-sensing chamber.
[0098] FIGS. 19 and 20 are a longitudinal cross-sectional view and
a left side view of the pressure control valve, respectively, all
illustrating an eighth embodiment of the present invention. The
pressure control valve 1H according to the eighth embodiment shown
herein is fundamentally the same in construction as that of the
pressure control valve 1E of the fifth embodiment (the portions or
members constructed or functioning in the same manner as those of
the pressure control valve 1E of the fifth embodiment will be
identified by the same reference numerals, thereby omitting the
explanations thereof). In the pressure control valve 1H of this
embodiment however, it is designed such that a large number of
annular trenches 15b are formed on the shaft portion 15a of the
valve rod 15A, thereby enabling the heat of the refrigerant in the
temperature-sensing chamber 60 to be readily detected by the shaft
portion 15a, thus enhancing the temperature-sensing function of the
shaft portion 15a. Further, the pressure control valve 1H is
provided, on the entire circumferential wall thereof, with a trench
64 for shielding the transmission of heat between the
pressure-adjusting inlet port 11 and the pressure-adjusting outlet
port 12.
* * * * *