EP4726286A1

EP4726286A1 - Expansion valve

Info

Publication number: EP4726286A1
Application number: EP24819070.4A
Authority: EP
Inventors: Hideyuki Yanagiya; Takashi Mogi
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2023-06-07
Filing date: 2024-05-08
Publication date: 2026-04-15
Also published as: CN121285716A; WO2024252833A1; JP2024175801A

Abstract

Provided is an expansion valve that may ensure a valve closed state as needed by utilizing fluid pressure of a refrigeration cycle.

The expansion valve includes a valve main body including a valve chamber and a valve seat, a power element disposed on the valve main body and including a displacement portion configured displaceably, a valve element disposed in the valve chamber, a first urging device configured to urge the valve element toward the valve seat, an actuation rod disposed at the valve main body and arranged between the displacement portion and the valve element, the actuation rod configured to drive the valve element by receiving displacement of the displacement portion, a syringe member disposed at the valve main body, the syringe member configured to accommodate a portion of the actuation rod movably in an interior thereof, and to constitute a cylinder chamber that is extensible in a movement direction of the valve element between itself and the displacement portion, a movement regulation portion configured to regulate movement of the syringe member toward the valve chamber, and a supplying portion configured to supply a fluid within the valve chamber or a fluid on an upstream side of the valve chamber to the cylinder chamber.

Description

[Technical Field]

The present invention relates to expansion valves.

[Background Art]

An expansion valve equipped with an electromagnetic valve is known as one type of expansion valves. This type of expansion valve is adopted, for example, in a refrigeration cycle in which a plurality of evaporators are connected in parallel, and has a shutoff function for breaking a circuit of the refrigeration cycle in addition to a superheat control function of refrigerant at an outlet side of the evaporator.
Patent Literature 1 discloses an expansion valve having a valve port disposed on a communication passage that connects a valve chamber and a primary-side passage through which high-pressure refrigerant flows in, and further having an electromagnetic valve that opens and closes the valve port disposed thereto.

[Citation List]

[Patent Literature]

[Patent Literature 1] Publication of Japanese Patent No. 3362990

[Summary of Invention]

[Technical Problem]

According to the configuration of Patent Literature 1, by opening the valve port using an electromagnetic valve, the expansion valve may be activated, and by closing the valve port, the expansion valve may be set forcibly to a valve closed state.
However, according to the expansion valve of Patent Literature 1, the electromagnetic valve and the expansion valve are in a state connected in series. That is, the refrigerant having entered a primary-side passage must pass through two locations, which are an orifice of the electromagnetic valve and an orifice of the expansion valve, before flowing out to the exterior of the expansion valve, such that pressure loss is increased.
In consideration of the problems described above, the present invention aims at providing an expansion valve that may ensure a valve closed state as needed by utilizing a fluid pressure of a refrigeration cycle.

[Means to Solve the Problem]

An expansion valve according to the present invention includes

a valve main body including a valve chamber and a valve seat,
a power element disposed on the valve main body and including a displacement portion configured displaceably,
a valve element disposed in the valve chamber,
a first urging device configured to urge the valve element toward the valve seat,
an actuation rod disposed at the valve main body and arranged between the displacement portion and the valve element, the actuation rod configured to drive the valve element by receiving displacement of the displacement portion,
a syringe member disposed at the valve main body, the syringe member configured to accommodate a portion of the actuation rod movably in an interior thereof, and to constitute a cylinder chamber that is extensible in a movement direction of the valve element between itself and the displacement portion,
a movement regulation portion configured to regulate movement of the syringe member toward the valve chamber, and
a supplying portion configured to supply a fluid within the valve chamber or a fluid on an upstream side of the valve chamber to the cylinder chamber.

[Effects of Invention]

The present invention enables to provide an expansion valve capable of ensuring a valve closed state as needed by utilizing the fluid pressure of a refrigeration cycle.

[Brief Description of Drawings]

FIG. 1 is a schematic cross-sectional view of a valve opened state of an expansion valve according to a first embodiment.
FIG. 2 is a vertical cross-sectional view of the expansion valve in a cross section with a phase varied by 90 degrees about an axis L from the state of FIG. 1.
FIG. 3 is a cross-sectional view of a periphery of an electromagnetic valve illustrated in FIG. 2 in enlarged view.
FIG. 4 is a vertical cross-sectional view of a valve closed state of the expansion valve in a cross section similar to FIG. 2.
FIG. 5 is a vertical cross-sectional view of a valve opened state of an expansion valve according to a second embodiment.
FIG. 6 is a vertical cross-sectional view of a valve closed state of the expansion valve according to the second embodiment.
FIG. 7 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a first modified example.
FIG. 8 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a second modified example.
FIG. 9 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a third modified example.
FIG. 10 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a fourth modified example.
FIG. 11 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a fifth modified example.
FIG. 12 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a sixth modified example.

[Description of Embodiments]

(First Embodiment)

A configuration of an expansion valve 1 according to a first embodiment will be described below with reference to FIG. 1.
FIG. 1 is a schematic cross-sectional view of the expansion valve 1 according to the present embodiment in a valve opened state, and schematically illustrates a refrigeration cycle 100 to which the expansion valve is connected. FIG. 2 is a vertical cross-sectional view of the expansion valve 1 in a cross-section with a phase varied by 90 degrees about an axis L from FIG. 1, illustrating a valve opened state. FIG. 3 is a cross-sectional view of a periphery of an electromagnetic valve EV illustrated in FIG. 2 in enlarged view. FIG. 4 is a vertical cross-sectional view of the expansion valve 1 in a similar cross-section as FIG. 2, illustrating a valve closed state. Upstream of a valve chamber refers to a side closer to a condenser than the valve chamber, and downstream of the valve chamber refers to a side closer to an evaporator than the valve chamber.
The expansion valve 1 includes a valve main body 2 equipped with a valve chamber VS, a valve element 3, an urging device, also referred to as a first urging device, 4, an actuation rod 5, a syringe member 6, and a power element 8. An axis of the expansion valve 1 is referred to as L. Along the axis L, the power element 8 side is referred to as upward, and in contrast, the urging device 4 side is referred to as downward.
The valve main body 2 includes, in addition to the valve chamber VS, a first flow passage 21, a second flow passage 22, and a return flow passage, i.e., low-pressure flow passage 23. The first flow passage 21 is a feed-side flow passage, and refrigerant, also referred to as fluid, is supplied to the valve chamber VS via the feed-side flow passage. The second flow passage 22 is a discharge-side flow passage, and the fluid in the valve chamber VS flows through an actuation rod insertion hole 27, an intermediate passage 22a, and a discharge-side flow passage to be discharged to the exterior of the expansion valve. The first flow passage 21 and the valve chamber VS are communicated via a small-diameter passage 21a.
The valve element 3 having a spherical shape is arranged in the valve chamber VS. In a state where the valve element 3 is seated on a valve seat 20 having an annular shape in the valve main body 2, the valve chamber VS and the second flow passage 22 are in a non-communicated state. Meanwhile, in a state where the valve element 3 is distanced from the valve seat 20, the valve chamber VS and the second flow passage 22 are in a communicated state.
The actuation rod 5 is passed through the actuation rod insertion hole 27 of the valve main body 2 with a gap therebetween, and the actuation rod 5 is guided by a center hole 28 and held displaceably in the axis L direction. A lower end of the actuation rod 5 is in contact with an upper surface of the valve element 3, and an upper end of the actuation rod 5 is abutted against a lower surface of a stopper member 84 of the power element 8.
The actuation rod 5 may press the valve element 3 toward a valve opening direction against an urging force applied from the urging device 4. When the actuation rod 5 moves to the valve element side, the valve element 3 is distanced from the valve seat 20, and the expansion valve 1 will be in an opened state.
The syringe member 6 arranged in a circumference of the actuation rod 5 is disposed in the valve main body 2, accommodating a portion of the actuation rod 5 movably in the interior thereof, and constituting a cylinder chamber which is extensible in a movement direction of the valve element 3 between itself and the stopper member 84. The syringe member 6 is formed by coaxially consecutively connecting a disk-shaped base portion, also simply referred to as base portion, 61 disposed on an upper end side, and a lower end-side shaft portion, also referred to as a syringe member shaft portion, 62, and includes a through hole 63 formed to pass through from the upper end side to the lower end. The through hole 63 includes a first hole 63a on the upper end side, and a second hole 63b on the lower end side. The second hole 63b has a smaller inner diameter than the first hole 63a, and fit slidably to an outer circumference of the actuation rod 5.
The disk-shaped base portion 61 is accommodated in a tubular recess portion 84a of a stopper member 84 described below of the power element 8. A first circumferential groove 61a is formed on an outer circumference of the disk-shaped base portion 61, and in an interior thereof is disposed a first O-ring OR1, which provides a seal between the tubular recess portion 84a and the disk-shaped base portion 61.
On an outer circumference in a vicinity of a lower end of the shaft portion 62 is formed a second circumferential groove 62a, and inside the groove is disposed a second O-ring OR2, providing a seal between a diameter expansion hole, i.e., first hole, 26 of the valve main body 2 and the shaft portion 62. The shaft portion 62 fits slidably in the diameter expansion hole 26.
A narrow diameter portion 62b is formed on an outer circumference at a lower end of the shaft portion 62 below the narrow diameter portion 62b, and an outer diameter of the narrow diameter portion 62b is set smaller than an outer diameter of the shaft portion 62 excluding the narrow diameter portion 62b. A connection hole 62d passing through the inner circumference and the outer circumference is formed at the narrow diameter portion 62b. Since the diameter expansion hole 26 has an approximately uniform inner diameter, a gap is formed between an outer circumference of a diameter reduction portion 64 and an inner circumference of the diameter expansion hole 26.
A medium diameter hole 29 that has a smaller diameter than the diameter expansion hole 26 and a larger diameter than the center hole 28 is formed between the diameter expansion hole 26 and the center hole 28 of the valve main body 2. A third O-ring OR3 through which the actuation rod 5 is passed is disposed within the medium diameter hole 29, providing a seal between the actuation rod 5 and the medium diameter hole 29.
A space between the diameter expansion hole 26 and the medium diameter hole 29 sealed by the second O-ring OR2 and the third O-ring OR3 is referred to as a pressure equalizing chamber, also called pressure equalizing space, EC. A communication hole 2d that extends in an inclined manner with respect to the axis L downward from the diameter expansion hole 26 facing the pressure equalizing chamber EC is formed on the valve main body 2 (refer to FIG. 2).
The syringe member 6 extends from the power element 8 to a stepped portion 26a between the diameter expansion hole 26 and the medium diameter hole 29 along the axis L via a communication passage 2b, a return flow passage 23, and the diameter expansion hole 26 formed on the valve main body 2.
Next, the power element 8 will be described. The power element 8 is attached to an opening portion 2a formed at a top portion of the valve main body 2. The opening portion 2a communicates via the communication passage 2b with the return flow passage 23 through which refrigerant from an evaporator flows.
The power element 8 includes a plug 81, an upper lid member 82, a diaphragm 83, the stopper member 84 constituting a displacement portion, and a receiving member 86.
A hole 82a is formed at a top portion of the upper lid member 82, which may be sealed by the plug 81.
The diaphragm 83 may be formed of a thin plate member on which a plurality of concentric circles are embossed, for example.
The stopper member 84 having an approximately cylindrical shape with a top includes a disk portion 84b, and a circular tube portion 84c coaxially consecutively connected to the lower surface of the disk portion 84b, and wherein the inner side of the circular tube portion 84c constitutes the tubular recess portion 84a. A locking member, also referred to as locking portion, 85 having an annular shape is attached to the inner circumference stepped portion at a lower end of the circular tube portion 84c. By caulking a caulking portion 84d at a lower end of the circular tube portion 84c arranged at an outer circumference of the locking member 85 to a radially inward direction after inserting the disk-shaped base portion 61 of the syringe member 6 to the tubular recess portion 84a, the locking member 85 is attached to the circular tube portion 84c, and thereby, the disk-shaped base portion 61 is retained on the stopper member 84.
That is, by abutting against the syringe member 6, the locking member 85 prevents the syringe member 6 from moving toward the valve chamber side beyond a predetermined position with respect to the stopper member 84. In other words, the locking member 85 prevents the syringe member 6 from falling from the stopper member 84. Further, regarding the stopper member 84, an example has been illustrated in which the portion abutting against the syringe member 6 is formed as an independent member as the locking member 85, but in the stopper member 84, the portion abutting against the syringe member 6 may be formed integrally with the stopper member 84.
The disk-shaped base portion 61 is displaceable in the axial direction between an upper position where its upper end is abutted against a lower surface of the disk portion 84b, i.e., abutted position abutted against the stopper member 84 (FIG. 2), and a lower position where its lower end is abutted against an upper surface of the locking member 85. However, in an assembled state of the expansion valve 1, the shaft portion 62 abuts against a stepped portion, also referred to as a bottom surface of hole, 26a between the diameter expansion hole 26 and the medium diameter hole 29 before the disk-shaped base portion 61 abuts against the locking member 85. That is, the stepped portion of the medium diameter hole 29 functions as a movement regulation portion that regulates movement of the syringe member 6 toward the valve chamber VS side. Therefore, in the valve closed state, an axial dimension of the syringe member 6 is set such that, in a state where a lower end of the shaft portion 62 is abutted against the stepped portion 26a between the diameter expansion hole 26 and the medium diameter hole 29, i.e., abutment position abutted against the valve main body 2 (FIG. 4), the disk-shaped base portion 61 is distanced from the lower surface of the disk portion 84b of the stopper member 84.
A space between the disk portion 84b and the disk-shaped base portion 61 is referred to as a cylinder chamber CS. The cylinder chamber CS only communicates with the through hole 63. An annular shaped recess portion 84e that is recessed in an annular shape facing the outer circumference of the upper end of the disk-shaped base portion 61 is formed on a lower surface of the disk portion 84b, and the inside of the annular shaped recess portion 84e constitutes a portion of the cylinder chamber CS.
The receiving member 86 includes a flange portion having an approximately similar outer diameter as an outer diameter of the upper lid member 82, and a hollow cylindrical portion connected consecutively to the lower end of the flange portion, with a male screw 86c formed on an outer circumference of the hollow cylindrical portion.
When assembling the power element 8, at first, respective outer circumference portions of flange portions of the upper lid member 82, the diaphragm 83, and the receiving member 86 are superposed, with the stopper member 84 interposed therebetween, and in that state, the outer circumference portions are circumferentially welded by TIG welding, laser welding, plasma welding, etc. to integrate the same and form a housing. In this state, the syringe member 6 may be assembled in advance within the stopper member 84, or the syringe member 6 may be assembled after welding.
Next, working gas is filled in a space surrounded by the upper lid member 82 and the diaphragm 83, referred to as a pressure working chamber PA, through the hole 82a formed on the upper lid member 82, the hole 82a is sealed by the plug 81, and thereafter, the plug 81 is fixed to the upper lid member 82 through projection welding and the like.
In this state, the diaphragm 83 receives pressure so as to project toward the receiving member 86 by the working gas sealed in the pressure working chamber PA, such that the diaphragm 83 is abutted against and supported by the upper surface of the stopper member 84 disposed in a lower space, i.e., valve chamber-side chamber, LS surrounded by the diaphragm 83 and the receiving member 86. Since the disk portion 84b of the stopper member 84 is held by the receiving member 86, the stopper member 84 will not fall out of the power element 8.
When assembling the power element 8 to the valve main body 2, after inserting the actuation rod 5 into the valve main body 2, the syringe member 6 together with the stopper member 84 is inserted into the valve main body 2 from the lower end side, and the second hole 63b is fit to the actuation rod 5. Further, by having the male screw 86c of the receiving member 86 screwed onto a female screw on the opening portion 2a of the valve main body 2 to be engaged thereon, the power element 8 is fixed to the valve main body 2. A packing PK seals the space between the valve main body 2 and the power element 8. In this state, the lower space LS of the power element 8 communicates with the return flow passage 23, that is, they are set to have a same internal pressure.
Next, the urging device 4 will be described. In FIG. 1, the urging device 4 includes a coil spring 41 in which a circular wire material is wound helically, a valve element support 42 attached to an upper end of the coil spring 41 and supporting the valve element 3, a spring receiving member 43 attached to the valve main body 2 while supporting a lower end of the coil spring 41, and a vibration isolation member 44 nipped between the valve element support 42 and the coil spring 41. The spring receiving member 43 functions not only to seal the valve chamber VS of the valve main body 2 but also to support the end portion of the coil spring 41 urging the valve element 3 toward the valve seat 20.
The valve element 3 having a spherical shape is welded to the upper surface of the valve element support 42, and the two members are thereby integrated. The vibration isolation member 44 has a hook portion that protrudes in the radial direction being elastically fit to an inner circumference of the valve chamber VS, for example, to suppress the vibration of the valve element 3. The vibration isolation member 44 is described in detail, for example in Japanese Patent Application Laid-Open Publication No. 2018-025331 , such that detailed descriptions thereof are omitted.

(Configuration of Electromagnetic Valve)

Next, a configuration of the electromagnetic valve EV according to the present embodiment will be described with reference to FIGs. 2 and 3. The electromagnetic valve EV is a first valve device and second valve device, or a driving portion, capable of switching between a state in which an inflow passage is opened and an outflow passage is closed and a state in which the outflow passage is opened and the inflow passage is closed. The inflow passage and the electromagnetic valve EV constitute a supplying portion and a discharging portion. An axis of the electromagnetic valve EV is referred to as O. The axis O is orthogonal to the axis L.
In FIG. 2, the valve main body 2 includes, along the axis O, a large opening 2e having a circular shape that is opened toward the exterior, a medium opening 2f having a smaller diameter than the large opening 2e, and a small opening 2g having a smaller diameter than the medium opening 2f formed thereto. A bottom portion of the large opening 2e and the valve chamber VS are communicated through an inlet hole 2h. Further, the communication hole 2d is opened on an inner circumference of an intermediate position of the medium opening 2f. Further, the bottom portion of the small opening 2g and the intermediate passage 22a are communicated through an outlet hole, also referred to as a connection passage, 2j.
The inlet hole 2h, the high pressure chamber HS, the medium opening 2f, the communication hole 2d, the diameter expansion hole 26, the connection hole 62d, and the through hole 63 constitute an inflow passage, the connection hole 62d and the through hole 63 constitute a second hole, the inlet hole 2h constitutes a first flow passage portion, and the communication hole 2d constitutes a second flow passage portion.
The through hole 63, the connection hole 62d, the diameter expansion hole 26, the communication hole 2d, the medium opening 2f, the small opening 2g, and an outlet hole 2j constitute the outflow passage. Further, the small opening 2g and the outlet hole 2j constitute a branched passage, the outlet hole 2j constitutes a third flow passage portion, and the high pressure chamber HS, the medium opening 2f, and the small opening 2g constitute a connecting chamber. The intermediate passage 22a constitutes a downstream passage on a downstream side of the valve seat 20.
In FIG. 3, a valve seat member 112 having a cylindrical shape is positioned in the medium opening 2f, and is fixed to the medium opening 2f by having a caulking portion 2i having a cylindrical shape formed at the bottom portion of a large opening, also referred to as a recess portion, 2e caulked inward in the radial direction. As described below, the valve seat member 112 is disposed between the opening of the first flow passage portion and the opening of the third flow passage portion within the connecting chamber to prevent the flow of refrigerant from the first flow passage portion to the third flow passage portion, to cover the opening of the second flow passage portion, and to form a gap between itself and the opening of the third flow passage portion.
The valve seat member 112 includes a round through hole, also referred to as a through hole, 112a extending along the axis O, a circumferential groove 112b formed across an entire circumference of an outer circumference of an intermediate position in the axis O direction, a radial direction hole 112c that communicates the round through hole 112a and the circumferential groove 112b in the radial direction, and a recess portion 112d formed at an end portion on the small opening 2g side. The circumferential groove 112b is communicated with the communicating passage 2d. The circumferential groove 112b and the radial direction hole 112c constitute a relay passage. A portion of the high pressure chamber HS, the round through hole 112a of the valve seat member 112, the radial direction hole 112c, and the circumferential groove 112b constitute a first communicating flow passage, and the round through hole 112a of the valve seat member 112, the radial direction hole 112c, the circumferential groove 112b, and the small opening 2g constitute a second communicating flow passage.
A first sealing member SL1 having an annular shape is attached by bonding etc. to the inner side of the recess portion 112d of the valve seat member 112, and a second sealing member SL2 having an annular shape is attached by bonding etc. to the end portion on the other side from the recess portion 112d. The inner diameters of the first sealing member SL1 and the second sealing member SL2 are approximately equal to the inner diameter of the round through hole 112a. The first sealing member SL1 abuts against a stepped portion at a boundary between the medium opening 2f and the small opening 2g, and the second sealing member SL2 abuts against an inner circumference of the medium opening 2f, by providing a seal between the valve seat member 112 and the valve main body 2.
A valve shaft member 113 having a column shape includes a long shaft portion, also simply referred to as a shaft portion, 113a that is inserted to pass through the round through hole 112a of the valve seat member 112 and the first sealing member SL1 and the second sealing member SL2, a flange portion, also referred to as a collar portion, 113b having a larger diameter than the round through hole 112a, and a short shaft portion 113c. A gap through which refrigerant may pass is formed between the outer circumference of the long shaft portion 113a and the inner circumference of the round through hole 112a, the first sealing member SL1 and the second sealing member SL2, and the valve shaft member 113 is relatively movable in the axis O direction with respect to the valve seat member 112. Specifically, the valve shaft member 113 is movable between a second position in which both the first flow passage portion and the second flow passage portion are communicated via the first communicating flow passage of the connecting chamber, and both the first flow passage portion and second flow passage portion are not communicated with the third flow passage portion, and a first position, in which the second flow passage portion and the third flow passage portion are communicated, and both the second flow passage portion and third flow passage portion are not communicated with the first flow passage portion.
In the circumference of the short shaft portion 113c, a compression spring, also referred to as a second urging device, 114 is arranged between a bottom portion of the small opening 2g and an opposing surface of the flange portion 113b, and the valve shaft member 113 is urged toward the large opening 2e with respect to the bottom portion of the small opening 2g. The electromagnetic valve EV and the compression spring 114 constitute a drive device.
The electromagnetic valve EV includes a base portion 120 having an annular shape, a coil 132 for energization and excitation, a yoke 133, a pipe 141 arranged on an inner circumference side of the yoke 133 and extending in the axis O direction, a plunger, i.e., displacement member, 135 arranged slidably in the axis O direction on the inner circumference side of the pipe 141, an attraction element 140 arranged and fixed to an inner circumference at an end portion of the pipe 141, and a housing 138 disposed to cover the above elements.
The end portion of the pipe 141 is fixed by press-fitting or brazing to the inner circumference of the base portion 120, and by screw-engaging a male screw 121 formed on an outer circumference of the base portion 120 to a female screw 2k formed on an inner circumference of the large opening 2e of the valve main body 2, the base portion 120 is fixed to the valve main body 2. An O-ring OR4 is arranged between the bottom portion of the large opening 2e and the base portion 120, providing a seal between the base portion 120 and the valve main body 2. Thereby, the high pressure chamber HS is formed between the base portion 120 and the large opening 2e. The high pressure chamber HS may communicate with the inlet hole 2h, and may communicate with the round through hole 112a of the valve seat member 112.
A female screw portion 142 is formed on an end surface of the attraction element 140 opposite from the pipe 141. By screw-engaging an attachment bolt 137 to the female screw portion 142 with the housing 138 interposed therebetween, the attraction element 140 and the housing 138 are joined. The housing 138 is fixed to the base portion 120 via a spacer 139.
The plunger 135 having a column shape is formed of a magnetic material, and it is formed by consecutively connecting a diameter expansion cylinder portion 135a, and a diameter reduction cylinder portion 135b having a larger diameter than the inner diameter of the round through hole 112a. A circular recess portion 135c is formed at an end portion of the diameter reduction cylinder portion 135b, to which an end portion of the long shaft portion 113a of the valve shaft member 113 exposed through the valve seat member 112 is loosely fit, that is, fit in a manner relatively displaceable in the axis O direction. The plunger 135 is urged toward the valve seat member 112 side by a compression coil spring 136 that is arranged in a compressed manner between the plunger 135 and the attraction element 140. A tip surface of the plunger 135 is formed at a surface that causes the opening of the round through hole 112a and the connecting chamber to be non-communicated by abutting against the valve shaft member 113.

(Operation of Expansion Valve)

An operation example of a state in which the expansion valve 1 is assembled in the refrigeration cycle 100 will be described with reference to FIG. 1. The refrigerant pressurized by a compressor 101 in the refrigeration cycle 100 is liquefied in a condenser 102 and sent to the expansion valve 1. The refrigerant subjected to adiabatic expansion in the expansion valve 1 is delivered to an evaporator 103 in the refrigeration cycle 100, where heat exchange is performed with air flowing around the evaporator 103. The refrigerant returning from the evaporator 103 is passed through the expansion valve 1, more specifically, the return flow passage 23, and returned to the compressor 101 side.
Now, as illustrated in FIG. 2, the plunger 135 of the electromagnetic valve EV is assumed to be at a first position described later. In the first position, as described later, the pressure of refrigerant of the cylinder chamber CS is approximately equal to a pressure of the intermediate passage 22a and also the return flow passage 23. Thereby, the stopper member 84 may approach the syringe member 6, and thereby, the actuation rod 5 may be driven according to the deformation of the diaphragm 83, and the expansion valve 1 may perform its proper valve opening operation.
A high pressure refrigerant is supplied to the expansion valve 1 from the condenser 102. More specifically, the high pressure refrigerant from the condenser 102 is supplied to the first flow passage 21.
In a state where the valve element 3 is seated on the valve seat 20, the first flow passage 21 on the upstream side of the valve chamber VS and the second flow passage 22 on the downstream side of the valve chamber VS are in a non-communicated state. Meanwhile, in a state where the valve element 3 is distanced from the valve seat 20, the refrigerant supplied to the valve chamber VS is passed through the actuation rod insertion hole 27 and the second flow passage 22 and sent to the evaporator. The switching between the closed state (refer to FIG. 4) and the opened state (FIG. 2) of the expansion valve 1 is performed by the actuation rod 5 connected to the power element 8.
The pressure working chamber PA and the lower space LS partitioned by the diaphragm 83 are disposed in the inner side of the power element 8. Therefore, when the working gas within the pressure working chamber PA is liquefied, the actuation rod 5 moves to the diaphragm side by the urging force of the urging device 4, and when the liquefied working gas is vaporized, the driving force, i.e., valve opening force, of the power element 8 is transmitted via the stopper member 84, and the actuation rod 5 moves toward the valve element side. Thereby, switching between the opened state and the closed state of the expansion valve 1 is performed.
Further, the lower space LS of the power element 8 is communicated with the return flow passage 23. Therefore, the phase of the working gas within the pressure working chamber PA is varied, such as between a vapor phase and a liquid phase, according to the temperature and pressure of refrigerant flowing through the return flow passage 23, and the actuation rod 5 is driven. In other words, according to the expansion valve 1 illustrated in FIG. 1, the amount of refrigerant supplied from the expansion valve 1 toward the evaporator is adjusted automatically according to the temperature and pressure of the refrigerant returning from the evaporator to the expansion valve 1.

(Forcible Valve Closing Operation of Expansion Valve)

Next, a forcible valve closing operation of the expansion valve 1 using the electromagnetic valve EV will be described. In the electromagnetic valve EV, a position at which the plunger 135 abuts against the valve seat member 112 is referred to as a first position, and a position at which the plunger 135 is distanced from the valve seat member 112 is referred to as a second position. A high pressure refrigerant is supplied from the valve chamber VS via the inlet hole 2h to the high pressure chamber HS between the base portion 120 and the valve main body 2.
When power is fed to the coil 132 from an external feeding device, as illustrated in FIG. 4, the plunger 135 is urged and moved to a direction separating from the valve seat member 112 against the urging force of the compression coil spring 136. Thereby, the end portion of the plunger 135 separates from the second sealing member SL2, and the urging force of the compression spring 114 causes the flange portion 113b of the valve shaft member 113 to abut against the first sealing member SL1, by which the plunger 135 of the electromagnetic valve EV is set to the second position.
In the second position, the pressure of the refrigerant in the high pressure chamber HS is transmitted from the round through hole 112a of the valve seat member 112 via the radial direction hole 112c, the circumferential groove 112b, the communication hole 2d, the pressure equalizing chamber EC, the connection hole 62d, the gap between the actuation rod 5 and the second hole 63b, and the through hole 63 to the cylinder chamber CS.
The side of the syringe member 6 opposite from the cylinder chamber CS interposing the disk-shaped base portion 61 faces the return flow passage, i.e., low pressure space, 23 through which a low pressure refrigerant passes. When the cylinder chamber CS is set to high pressure, the cylinder chamber CS attempts to expand according to the pressure difference with the pressure of the refrigerant in the return flow passage 23. Meanwhile, the lower end of the shaft portion 62 of the syringe member 6 is maintained in a state abutted against the stepped portion 26a between the diameter expansion hole 26 and the medium diameter hole 29, such that when the cylinder chamber CS is set to high pressure, the stopper member 84 is moved relatively upward. Thereby, the transmission of driving force of the stopper member 84 pressing the actuation rod 5 downward is interrupted, such that the valve element 3 is urged upward by the urging force of the urging device 4 to be seated on the valve seat 20, and a forcible valve closed state is maintained regardless of the pressure difference between the pressure working chamber PA and the lower space LS.
Since the pressure in the cylinder chamber CS is high, an upward force by which the diaphragm 83 is pressed is applied via the stopper member 84, but at the same time, a downward force pressing the disk-shaped base portion 61 downward is also applied. This downward force is supported by the locking member 85, and thereby, the upward force urging the stopper member 84 upward is cancelled, such that an influence such as the diaphragm 83 being deformed may be prevented.
Meanwhile, if power is not fed to the coil 132 from an external feeding device, as illustrated in FIG. 2, the plunger 135 is urged and moved toward the valve seat member 112 by the urging force of the compression coil spring 136. Thereby, the end portion of the plunger 135 abuts against the second sealing member SL2, and the flange portion 113b of the valve shaft member 113 separates from the first sealing member SL1, such that the plunger 135 of the electromagnetic valve EV is set to the first position.
In this state, since the end portion of the plunger 135 abuts against the second sealing member SL2, the refrigerant in the high pressure chamber HS is suppressed from passing through the round through hole 112a and leaking to the intermediate passage 22a, such that the operation of the refrigeration cycle 100 will not be affected.
Immediately after the flange portion 113b of the valve shaft member 113 has been separated from the first sealing member SL1, the internal pressure of the cylinder chamber CS is higher than the pressure of the refrigerant within the intermediate passage 22a. Therefore, at the first position, the pressure within the intermediate passage 22a is transmitted via the outlet hole 2j, the small opening 2g, the round through hole 112a, the radial direction hole 112c, the circumferential groove 112b, the communication hole 2d, the pressure equalizing chamber EC, the connection hole 62d, the gap between the actuation rod 5 and the second hole 63b, and the through hole 63 to the cylinder chamber CS, and the pressure of refrigerant within the cylinder chamber CS drops speedily so as to be approximately equal to the pressure within the intermediate passage 22a and the return flow passage 23. Thereby, force that pushes up the stopper member 84 is eliminated, such that pressing force from the diaphragm 83 may be transmitted to the upper end of the actuation rod 5, and the forcible valve closed state is cancelled.
In this state, the plunger 135 is abutted against the second seal SL2, such that the refrigerant is suppressed from leaking from the high pressure chamber HS through the round through hole 112a to the small opening 2g side, and the internal pressure of the pressure equalizing chamber EC and the cylinder chamber CS is maintained at low pressure. Therefore, a normal valve opening operation of the expansion valve 1 may be executed.
According to the present embodiment, by feeding power to the electromagnetic valve EV, the high pressure refrigerant supplied from the condenser 102 may be introduced to the cylinder chamber CS and the stopper member 84 may be pushed up, and thereby, a forcible valve closing function of the expansion valve 1 may be realized regardless of the pressure within the pressure working chamber PA. In this state, the refrigerant from the condenser 102 may be introduced directly into the valve chamber VS without passing through the electromagnetic valve EV, such that pressure losses may be suppressed.
Moreover, by interrupting the feeding of power to the electromagnetic valve EV, the cylinder chamber CS and the intermediate passage 22a may be communicated, by which the internal pressure within the cylinder chamber CS may be reduced speedily, such that the force pushing up the stopper member 84 from the cylinder chamber CS may be eliminated speedily, and the transmission of pressing force from the diaphragm 83 via the stopper member 84 to the actuation rod 5 may be resumed, such that the proper valve opening operation of the expansion valve 1 may be performed.
The pressure of high pressure refrigerant supplied from the condenser 102 varies according to condition, such that when high pressure refrigerant is used to execute a normal valve opening and closing operation, the normal valve opening and closing operation may become unstable. In contrast, according to the present embodiment, the high pressure refrigerant is used to execute a forcible valve closing operation, such that it is advantageous in that the normal valve opening and closing operation may be executed stably.
Moreover, with respect to the valve main body 2, the syringe member 6 is supported via the second O-ring OR2 which is formed either of natural resin or synthetic resin, and the actuation rod 5 is supported via the third O-ring OR3 which is formed either of natural resin or synthetic resin. Therefore, even if vibration occurs to the syringe member 6 or the actuation rod 5, the vibration may be suppressed by the damping function of the second O-ring OR2 and the third O-ring OR3.

(Second Embodiment)

FIG. 5 is a schematic cross-sectional view of a valve opened state of an expansion valve 1A according to a second embodiment, and FIG. 6 is a vertical cross-sectional view of a valve closed state of the expansion valve 1A according to the second embodiment, wherein both figures schematically illustrate a refrigeration cycle 100A to which the expansion valve 1A is connected.
In the present embodiment, an opening/closing valve is disposed by additionally providing a branch pipe to the refrigeration cycle 100A instead of the electromagnetic valve according to the first embodiment. Therefore, the configuration of a valve main body 2A differs in addition to the branch pipe from the embodiment described above, and a syringe member 6A is equipped with a hole 6e serving as a discharging portion. The other configurations are similar to the first embodiment, such that common components are denoted with the same reference numbers, and descriptions thereof are omitted.
In the refrigeration cycle 100A of the present embodiment, a branch pipe, i.e., an inflow passage that is connected to an external flow passage portion upstream of the valve chamber for introducing the refrigerant upstream of the valve chamber into the cylinder chamber, DP that is branched from a pipe extending from the condenser 102 toward the valve chamber VS of the expansion valve 1A and leading to a piping base portion 105A of the expansion valve 1A is disposed, and to the branch pipe DP is attached an opening and closing valve, i.e., valve device, VL. The opening and closing valve VL may be operated selectively to an open position for opening the branch pipe DP and a closed position for closing the same. The inflow passage and the opening and closing valve VL constitute the supplying portion and the discharging portion. The other configurations are similar to the refrigeration cycle of the first embodiment.
The communicating hole 2d communicates the pressure equalizing chamber EC of the valve main body 2A and an outer circumference of an end portion of a large opening 2Ae. The piping base portion 105A is attached to the large opening 2Ae. By engaging a male screw formed on an outer circumference of the piping base portion 105A to a female screw formed on an inner circumference of the large opening 2Ae of the valve main body 2A, the piping base portion 105A may be fixed to the valve main body 2A. The packing PK is disposed between the large opening 2Ae and the piping base portion 105A, providing a seal between the piping base portion 105A and the valve main body 2A. Thereby, the high pressure chamber HS is formed between the piping base portion 105A and the large opening 2Ae.
The piping base portion 105A includes a piping portion 105Aa connected to the branch pipe DP via the opening and closing valve VL. The high pressure chamber HS communicates with the branch pipe DP via an internal flow passage of the piping base portion 105A and the piping portion 105Aa, and communicates with the pressure equalizing chamber EC via the communication hole 2d, but is not communicated with the valve chamber VS. The other configurations are similar to the expansion valve of the first embodiment.
The syringe member 6A includes the hole 6e that allows the pressure within the cylinder chamber CS to escape to a downstream side of the valve chamber VS. The hole 6e is formed on the shaft portion 62 of the piston member 6A, for example. The hole 6e communicates the through hole 63 and the return flow passage 23. The hole 6e has a size such that, during normal use of the expansion valve 1A other than when performing the forcible valve closing operation, the hole 6e discharges pressure of the cylinder chamber CS to allow the actuation rod 5 to drive the valve element 3, and when performing the forcible valve closing operation, pressure in the cylinder chamber CS may be maintained to a sufficient level such that the forcible valve closing operation may be performed speedily.
According to the present embodiment, one hole is illustrated as the hole 6e, but the number of the hole 6e is not limited to one, and there may be multiple holes. Further, the shape of the hole 6e may be a hole with a circular planar shape, but the shape of the hole 6e is not limited thereto. The hole 6e may be a slit, or a long hole having a planar shape that is long in one direction.
Next, a forcible valve closing operation of the expansion valve 1A using the opening and closing valve VL will be described. In the opening and closing valve VL, a position opening the branch pipe DP is referred to as a first position, and a position closing the branch pipe DP is referred to as a second position.
When the opening and closing valve VL takes the second position, i.e., open position, the high pressure refrigerant in the branch pipe DP is supplied via the piping portion 105Aa to the high pressure chamber HS, and the pressure of the refrigerant in the high pressure chamber HS is transmitted via the communication hole 2d, the pressure equalizing chamber EC, the connection hole 62d, and the through hole 63 to the cylinder chamber CS, setting the internal pressure of the cylinder chamber CS to high pressure.
When the cylinder chamber CS is set to high pressure, as described above, the cylinder chamber CS is set to high pressure in a state where the lower end of the shaft portion 62 of the syringe member 6A is abutted against the stepped portion 26a between the diameter expansion hole 26 and the medium diameter hole 29, i.e., at an abutment position where the disk-shaped base portion 61 is separated from the disk portion 84b of the stopper member 84 and abuts against the valve main body 2A, the stopper member 84 is pushed relatively upward (FIG. 6). Thereby. the transmission of driving force of the stopper member 84 that presses the actuation rod 5 downward is interrupted, such that the valve element 3 is urged upward by the urging force of the urging device 4 and seated on the valve seat 20, such that a forcible valve closed state is maintained regardless of the pressure difference between the pressure working chamber PA and the lower space LS.
Meanwhile, in a state where the opening and closing valve VL is switched to the first position, i.e., closed position, the high pressure refrigerant in the branch pipe DP will not be transmitted to the high pressure chamber HS, and a portion of the refrigerant in the cylinder chamber CS gradually flows into the return flow passage 23 through the hole 6e formed on the shaft portion 62. Thereby, the internal pressure of the cylinder chamber CS drops, such that the force that pushes up the stopper member 84 is eliminated, and the disk-shaped base portion 61 will take the abutted position where it is abutted against the disk portion 84b of the stopper member 84 (FIG. 5), allowing the pressing force from the diaphragm 83 to be transmitted to the upper end of the actuation rod 5, such that the forcible valve closed state is cancelled.
According to the present embodiment, by operating the opening and closing valve VL to the second position, the high pressure refrigerant supplied from the compressor 101 is introduced to the cylinder chamber CS, by which the transmission of driving force from the diaphragm 83 to the actuation rod 5 is interrupted, and the forcible valve closing operation of the expansion valve 1 may be ensured.
In contrast, by operating the opening and closing valve VL to the first position, the pressure of the cylinder chamber CS may be lowered, by which the transmission of driving force from the diaphragm 83 to the actuation rod 5 may be resumed, and a proper opening and closing valve operation of the expansion valve 1 according to the operation of the power element 8 may be realized. According to the present embodiment, the refrigerant from the condenser 102 will not pass through the opening and closing valve VL, and is directly introduced into the valve chamber VS, such that pressure losses may be suppressed.
Instead of disposing the opening and closing valve VL in the branch pipe DP, a three-way selector valve may be disposed in midway of the piping from the condenser 102, and through the three-way selector valve, the high pressure refrigerant from the condenser 102 may be sent out via the branch pipe DP selectively to a flow passage leading to the high pressure chamber HS and to a flow passage leading to the valve chamber VS.
According to this case, by sending the high pressure refrigerant to the high pressure chamber HS via the branch pipe DP using the three-way selector valve, the internal pressure of the cylinder chamber CS may be set to high pressure, such that the forcible valve closing operation may be realized, and by sending the high pressure refrigerant to the valve chamber VS via the three-way selector valve, a proper expansion valve operation may be realized.
According to this example, the flow path to the high pressure chamber HS and the flow path to the valve chamber VS are switched via the three-way selector valve, but alternatively according to another example, by disposing a three-way selector valve instead of the opening and closing valve VL disposed on the branch pipe DP, a flow path connecting the condenser 102 and the high pressure chamber HS and a flow path connecting the high pressure chamber HS and an inlet side of the evaporator 103 may be switched selectively. By connecting the high pressure chamber HS and the inlet side of the evaporator 103 via the three-way selector valve, the pressure of the cylinder chamber CS may be lowered speedily. According to the modified example, there is no need to form the hole 6e on the syringe member 6A. The flow path that connects the high pressure chamber HS and the inlet side of the evaporator 103 may be, for example, a flow path connecting the high pressure chamber HS and the second flow passage 22 or a flow path connecting the high pressure chamber HS and the intermediate passage 22a.

(First Modified Example)

FIG. 7 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1B according to a first modified example, and illustrates a state in which it is disposed within the refrigeration cycle 100A illustrated schematically.
According to the expansion valve 1B of the present embodiment, only the shapes of a valve main body 2B and a syringe member 6B differ from the second embodiment, and the other configurations are similar to the second embodiment, such that common components are denoted with the same reference numbers and descriptions thereof are omitted.
The valve main body 2B forms, instead of the medium diameter hole accommodating the O-ring of the second embodiment, a pressure equalizing hole 29B that forms the pressure equalizing chamber EC is formed between the diameter expansion hole 26 and the center hole 28 in a manner connected to the communication hole 2d. A clearance is formed between the center hole 28 and the actuation rod 5. Even when high pressure is supplied to realize a forcible valve closing, as described below, the high pressure fluid flows out via the clearance, but the clearance is designed to have a size that allows the pressure within the cylinder chamber CS to be maintained to a pressure that may realize forcible valve closing. The other configurations of the valve main body 2B are similar to the second embodiment, such that descriptions thereof are omitted.
The syringe member 6B has a shaft portion 62B with a different shape, and the disk-shaped base portion 61 is similar to the second embodiment. The shaft portion 62B only has a through hole 63B with a uniform inner diameter, and does not include a circumferential groove on an outer circumference for accommodating an O-ring or a hole that communicates the inner and outer sides. The lower end of the shaft portion 62B is abutted against the stepped portion 26a between the diameter expansion hole 26 and the pressure equalizing hole 29B. The other configurations of the syringe member 6B are similar to the embodiments described above.
In the present modified example, when the opening and closing valve VL is set to the second position, i.e., open position, as illustrated in FIG. 7, the high pressure refrigerant within the branch pipe DP is supplied via the piping portion 105Aa to the high pressure chamber HS, and the pressure of the refrigerant in the high pressure chamber HS is transmitted via the communication hole 2d, the pressure equalizing chamber EC, and the through hole 63B to the cylinder chamber CS, by which the internal pressure of the cylinder chamber CS is set to high pressure. Thereby, the transmission of driving force of the stopper member 84 pushing the actuation rod 5 downward is interrupted, such that the valve element 3 is urged upward by the urging force of the urging device 4 to be seated on the valve seat 20, and a forcible valve closed state is maintained regardless of the pressure difference between the pressure working chamber PA and the lower space LS.
Meanwhile, when the opening and closing valve VL is set to the first position, i.e., closed position, the high pressure of the refrigerant within the branch pipe DP will not be transmitted to the high pressure chamber HS, and a portion of the refrigerant within the cylinder chamber CS will flow out through the through hole 63B and the gap between the center hole 28 and the actuation rod 5 into the intermediate passage 22a. Thereby, the internal pressure of the cylinder chamber CS drops, such that the force pushing up the stopper member 84 is eliminated, and the pressing force from the diaphragm 83 may be transmitted to the upper end of the actuation rod 5, such that the forcible valve closed state is cancelled.
According to the present modified example, the O-ring may be omitted, such that the ease of assembly is improved and costs may be cut down.

(Second Modified Example)

FIG. 8 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1C according to a second modified example, and illustrates a state in which the expansion valve 1C is disposed within the refrigeration cycle 100A illustrated schematically.
According to the expansion valve 1C of the present modified example, only the shapes of the valve main body 2C and the syringe member 6C differ from the second embodiment, and the other configurations are the same as the second embodiment, such that the common configurations are denoted with the same reference numbers and descriptions thereof are omitted.
The valve main body 2C has a communication passage 2Cb having an inner diameter that is smaller than an inner diameter of an opening portion, i.e., hole allowing the syringe member 6C to move therein, 2Ca with respect to the second embodiment, and therefore, a stepped portion, i.e., bottom surface of inner space of the opening portion 2Ca, 2Cm is formed between the opening portion 2Ca and the communication passage 2Cb. The other configurations of the valve main body 2C are similar to the second embodiment, such that descriptions thereof are omitted.
The syringe member 6C is formed by coaxially consecutively connecting a disk-shaped base portion, also simply referred to as a base portion, 61C on an upper end side, and a shaft portion, also referred to as a syringe member shaft portion, 62C on a lower end side, and includes a through hole 63C passed through from the upper end side to the lower end. The through hole 63C includes a first hole 63Ca on an upper end side and a second hole 63Cb on a lower end side. The disk-shaped base portion 61C is shaped such that a lower portion has a small diameter with respect to the upper portion, for example, and the portion having the small diameter is referred to as an intermediate portion 64C. The intermediate portion 64c serving as the other end of the shaft portion 62C and the stepped portion 2Cm, or the disk-shaped base portion 61C and the surface of the valve main body 2C facing the disk-shaped base portion 61C constitute the movement regulation portion. The second hole 63Cb has an inner diameter that is smaller than the first hole 63Ca, and fits slidably to the outer circumference of the actuation rod 5. A clearance is formed between the second hole 63Cb and the actuation rod 5. The clearance is set to an amount such that the high pressure fluid may flow therethrough from the pressure equalizing chamber EC to the cylinder chamber CS.
The disk-shaped base portion 61C is accommodated within the tubular recess portion 84a of the stopper member 84 which is hollow within the power element 8. A first circumferential groove 61Ca is formed on the outer circumference of the disk-shaped base portion 61C, and in the interior thereof is arranged the first O-ring OR1, sealing the space between the tubular recess portion 84a and the disk-shaped base portion 61C.
The intermediate portion 64C adjacent to the disk-shaped base portion 61C is passed through the locking member 85 having an annular shape, and the lower end thereof may abut against the stepped portion 2Cm of the opening portion 2Ca.
A second circumferential groove 62Ca is formed on an outer circumference in the vicinity of a lower end of the shaft portion 62C, and in the interior thereof is arranged the second O-ring OR2, sealing the space between the diameter expansion hole 26 of the valve main body 2C and the shaft portion 62C. The shaft portion 62C is slidably fit to the diameter expansion hole 26.
A narrow diameter portion 62Cb is formed at a lower end of the shaft portion 62C below the second circumferential groove 62Ca, facing the third O-ring OR3 accommodated within the medium diameter hole 29. The space between the narrow diameter portion 62Cb and the diameter expansion hole 26 serves as the pressure equalizing chamber EC. It is preferable that the lower end of the narrow diameter portion 62Cb does not come into contact with the third O-ring OR3 in a state where the lower end of the intermediate portion 64C of the syringe member 6C is abutted against the stepped portion 2Cm of the opening portion 2Ca. Further, the hole 6e that communicates the inner side and the outer side of the shaft portion 62C is formed.
In the present modified example, when the opening and closing valve VL is at the second position, i.e., open position, as illustrated in FIG. 8, the high pressure refrigerant within the branch pipe DP is supplied via the piping portion 105Aa to the high pressure chamber HS, and the pressure of the refrigerant within the high pressure chamber HS is transmitted via the communication hole 2d, the pressure equalizing chamber EC, the gap between the second hole 63Cb and the actuation rod 5, and the through hole 63C to the cylinder chamber CS. By setting the internal pressure of the cylinder chamber CS to high pressure in a state where the lower end of the intermediate portion 64C of the syringe member 6C is abutted against the stepped portion 2Cm of the opening portion 2Ca, the transmission of driving force of the stopper member 84 that pushes the actuation rod 5 downward is interrupted, such that the valve element 3 is urged upward by the urging force of the urging device 4 and seated on the valve seat 20, and a forcible valve closed state is maintained regardless of the pressure difference between the pressure working chamber PA and the lower space LS.
Meanwhile, when the opening and closing valve VL is set to the first position, i.e., closed position, the high pressure of the refrigerant within the branch pipe DP will not be transmitted to the high pressure chamber HS, and a portion of the refrigerant within the cylinder chamber CS gradually flows into the return flow passage 23 through the hole 6e formed on the shaft portion 62C. Thereby, the internal pressure of the cylinder chamber CS drops, and the force that pushes up the stopper member 84 is eliminated, such that the pressing force from the diaphragm 83 may be transmitted to the upper end of the actuation rod 5, and the forcible valve closed state is cancelled.
In the second embodiment, in order to realize the forcible valve closing operation, the axial dimension of the syringe member 6 is set such that the disk-shaped base portion 61 is distanced from the lower surface of the disk portion 84b of the stopper member 84 in a state where the lower end of the shaft portion 62 is abutted against the stepped portion 26a between the diameter expansion hole 26 and the medium diameter hole 29. Therefore, it becomes necessary to manage the entire length of the syringe member 6 having a relatively long length and the dimension from the upper end of the valve main body 2C to the stepped portion 26a between the diameter expansion hole 26 and the medium diameter hole 29, which is troublesome.
In contrast, according to the present modified example, in order to realize a forcible valve closing operation, it is merely necessary to manage the dimension of the intermediate portion 64C which is relatively close to the upper end of the syringe member 6C, and the dimension from the valve main body 2C to the stepped portion 2Cm of the opening portion 2Ca, such that the manufacturability is enhanced.

(Third Modified Example)

FIG. 9 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1D according to a third modified example, and illustrates a state in which the expansion valve 1D is disposed within the refrigeration cycle 100A illustrated schematically.
According to the expansion valve 1D of the present modified example, only the shapes of a power element 8D and a syringe member 6D differ from the second modified example, and the other configurations are the same as the second embodiment including the valve main body 2A, such that the common configurations are denoted with the same reference numbers and descriptions thereof are omitted.
The power element 8D only differs in the shapes of a stopper member 84D and a receiving member 86D with respect to the second embodiment, and the plug 81, the upper lid member 82, and the diaphragm 83 are similar to the second embodiment, such that the common configurations are denoted with the same reference numbers and descriptions thereof are omitted.
The receiving member 86D includes a first flange portion 86Da having an annular shape whose outer circumference is welded to the upper lid member 82, a first cylindrical portion 86Db that is connected to an inner edge of the first flange portion 86Da and that extends downward, a second flange portion 86Dc having an annular shape that is connected to a lower end of the first cylindrical portion 86Db and that extends inward in the radial direction, and a second cylindrical portion 86Dd that is connected to an inner edge of the second flange portion 86Dc and that extends downward. A male screw 86De that is screw-engaged to a female screw formed on an inner circumference of the opening portion 2a is formed on an outer circumference of the second cylindrical portion 86Dd.
The syringe member 6D is formed by coaxially consecutively connecting a disk-shaped base portion, also simply referred to as a base portion, 61D on an upper end side, and a shaft portion, also referred to as a syringe member shaft portion, 62D on a lower end side, and includes a through hole 63D formed to pass through from the upper end side to the lower end. As an example, according to the present embodiment, the disk-shaped base portion 61D is formed such that the lower portion has a small diameter compared to the upper portion. The portion formed to have a small diameter is referred to as an intermediate portion 64D. According to the present modified example, the disk-shaped base portion 61D, and the second flange portion 86Dc that abuts against the intermediate portion 64D constituting a portion of the disk-shaped base portion 61D constitute a movement regulation portion that regulates movement of the syringe member 6D toward the valve chamber VS side. The through hole 63D includes a first hole 63Da on an upper end side and a second hole 63Db on a lower end side. The second hole 63Db has a smaller inner diameter than the first hole 63Da, and fits slidably to the outer circumference of the actuation rod 5. A clearance is formed between the second hole 63Db and the actuation rod 5. The clearance is set to an amount such that the high pressure fluid may flow therethrough from the pressure equalizing chamber EC to the cylinder chamber CS.
The disk-shaped base portion 61D is accommodated within a cylindrical recess portion 84Da of the stopper member 84D of the power element 8D. A first circumferential groove 61Da is formed on an outer circumference of the disk-shaped base portion 61D, and in the interior thereof is arranged the first O-ring OR1, sealing the space between the cylindrical recess portion 84Da and the disk-shaped base portion 61D.
The intermediate portion 64D adjacent to the disk-shaped base portion 61D is passed through the locking member 85 having an annular shape, and the lower end thereof may abut against the upper surface of the second flange portion 86Dc of the receiving member 86D of the power element 8D.
A second circumferential groove 62Da is formed on an outer circumference in the vicinity of a lower end of a shaft portion 62D, and in the interior thereof is arranged the second O-ring OR2, sealing the space between the diameter expansion hole 26 of the valve main body 2A and the shaft portion 62D. The shaft portion 62D is slidably fit to the diameter expansion hole 26.
A narrow diameter portion 62Db is formed at a lower end of the shaft portion 62D below the second circumferential groove 62Da, facing the third O-ring OR3 accommodated within the medium diameter hole 29. The space between the narrow diameter portion 62Db and the diameter expansion hole 26 serves as the pressure equalizing chamber EC. It is preferable that the lower end of the narrow diameter portion 62Cb does not come into contact with the third O-ring OR3, and that an end surface on the valve chamber side of the disk-shaped base portion 61D is positioned on the valve chamber side than the end surface of the valve chamber side of the stopper member 84D, in a state where the lower end of the intermediate portion 64D of the syringe member 6D is abutted against the upper surface of the second flange portion 86Dc of the receiving member 86D. Further, the hole 6e that communicates the inner and outer sides of the shaft portion 62D is formed.
The stopper member 84D includes a disk portion 84Db, and a circular tube portion 84Dc connected to an outer circumference edge of the disk portion 84Db and extending downward. An inner side of the circular tube portion 84c constitutes the tubular recess portion 84a. The locking member 85 having an annular shape is attached to the inner circumference stepped portion at a lower end of the circular tube portion 84Dc. After inserting the disk-shaped base portion 61D of the syringe member 6D to the cylindrical recess portion 84Da, by caulking a caulking portion 84Dd at a lower end of the circular tube portion 84Dc arranged at an outer circumference of the locking member 85 to a radially inward direction, the locking member 85 is attached to the circular tube portion 84Dc, and thereby, the disk-shaped base portion 61D is retained on the stopper member 84D. The disk-shaped base portion 61D has a dimension facing, or abutting against, the second flange portion 86Dc in the movement direction of the shaft portion 62D.
In the present modified example, when the opening and closing valve VL is at the second position, i.e., open position, as illustrated in FIG. 9, the high pressure refrigerant within the branch pipe DP is supplied via the piping portion 105Aa to the high pressure chamber HS, and the pressure of the refrigerant in the high pressure chamber HS is transmitted via the communication hole 2d, the pressure equalizing chamber EC, the gap between the second hole 63Db and the actuation rod 5, and the through hole 63D to the cylinder chamber CS. By setting the internal pressure of the cylinder chamber CS to high pressure in a state where the lower end of the intermediate portion 64D of the syringe member 6D is abutted against the upper surface of the second flange portion 86Dv of the receiving member 86D, i.e., abutted position, the transmission of driving force of the stopper member 84D that pushes the actuation rod 5 downward is interrupted, such that the valve element 3 is urged upward by the urging force of the urging device 4 and seated on the valve seat 20, and a forcible valve closed state is maintained regardless of the pressure difference between the pressure working chamber PA and the lower space LS.
Meanwhile, when the opening and closing valve VL is set to the first position, i.e., closed position, the high pressure of the refrigerant within the branch pipe DP will not be transmitted to the high pressure chamber HS, and a portion of the refrigerant within the cylinder chamber CS gradually flows into the return flow passage 23 through the hole 6e formed on the shaft portion 62D. Thereby, the internal pressure of the cylinder chamber CS drops, and the force that pushes up the stopper member 84D is eliminated, the pressing force from the diaphragm 83 may be transmitted to the upper end of the actuation rod 5, and the forcible valve closed state is cancelled.
According to the present modified example, the intermediate portion 64D of the syringe member 6D may be abutted against the receiving member 86 that may be formed inexpensively by press forming, such that the processing to be performed to the valve main body side may be reduced, and costs may be cut down.

(Fourth Modified Example)

FIG. 10 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1E according to a fourth modified example, and illustrates a state in which the expansion valve 1E is disposed within the refrigeration cycle 100A illustrated schematically.
According to the expansion valve 1E of the present modified example, only the shapes of a valve main body 2E, a power element 8E, and a syringe member 6E differ from the second modified example, and the other configurations are similar to the second embodiment, such that the common configurations are denoted with the same reference numbers and descriptions thereof are omitted. According to the other embodiments and modified examples, the syringe member is arranged on the inner side of the stopper member, but according to the present modified example, a stopper member 84E is arranged on the inner side of the syringe member 6E.
The valve main body 2E differs from the second embodiment in that an inner diameter of a communication passage 2Eb is smaller than an inner diameter of an opening portion 2Ea, and therefore, a stepped portion 2Em is formed between the opening portion 2Ea and the communication passage 2Eb. The other configurations of the valve main body 2E are similar to the second embodiment, such that descriptions thereof are omitted.
The power element 8E differs from the second embodiment only in the shape of the stopper member 84E, and the plug 81, the upper lid member 82, the diaphragm 83, and the receiving member 86 are similar to the second embodiment, such that common configurations are denoted with the same reference numbers and detailed descriptions thereof are omitted.
The stopper member 84E having a column shape includes a diameter expansion column portion 84Ea, and a small diameter column portion 84Eb having a smaller diameter than the diameter expansion column portion 84Ea. A circumferential groove 84Ed is formed on an outer circumference of the diameter expansion column portion 84Ea, and in the interior thereof is disposed the first O-ring OR1.
The syringe member 6E is formed by coaxially consecutively connecting a circular tube base portion, also simply referred to as a base portion, 61E on an upper end side, and a shaft portion, also referred to as a syringe member shaft portion, 62E on a lower end side, via an intermediate portion 64E having an annular shape. According to the present modified example, a circumferential surface of an opening portion 2Eb that abuts against the intermediate portion 64E constituting a portion of the circular tube base portion 61E constitutes a movement regulation portion that regulates movement of the syringe member 6E toward the valve chamber VS side. The shaft portion 62E includes a through hole 63E that is formed to pass through from the upper end side to the lower end. The through hole 63E includes a first hole 63Ea on an upper end side, and a second hole 63Eb on a lower end side. The second hole 63Eb has an inner diameter that is smaller than the first hole 63Ea, and fits slidably to the outer circumference of the actuation rod 5. A clearance is formed between the second hole 63Eb and the actuation rod 5. The clearance is set to an amount such that the high pressure fluid may flow therethrough from the pressure equalizing chamber EC to the cylinder chamber CS.
The diameter expansion column portion 84Ea of the stopper member 84E is slidably fit to the inner circumference of the circular tube base portion 61E, and the first O-ring OR1 provides a seal between the stopper member 84E and the circular tube base portion 61E.
The locking member 85 having an annular shape is attached to the inner circumference stepped portion at an upper end of the circular tube base portion 61E. after inserting the diameter expansion column portion 84Ea of the stopper member 84E to the circular tube base portion 61E, by caulking a caulking portion 61Ea at an upper end of the circular tube base portion 61E arranged at an outer circumference of the locking member 85 to a radially inward direction, the locking member 85 is attached to the syringe member 6E, and thereby, the syringe member 6E is retained on the stopper member 84E.
A second circumferential groove 62Ea is formed on an outer circumference in the vicinity of a lower end of the shaft portion 62E, and in the interior thereof is arranged the second O-ring OR2, providing a seal between the diameter expansion hole 26 of the valve main body 2E and the shaft portion 62E. The shaft portion 62E is slidably fit to the diameter expansion hole 26.
A narrow diameter portion 62Eb is formed at a lower end of the shaft portion 62E below the second circumferential groove 62Ea, facing the third O-ring OR3 accommodated within the medium diameter hole 29. The space between the narrow diameter portion 62Eb and the diameter expansion hole 26 serves as the pressure equalizing chamber EC. It is preferable that the lower end of the narrow diameter portion 62Eb does not come into contact with the third O-ring OR3 in a state where the lower surface of the intermediate portion 64E of the syringe member 6E is abutted against the stepped portion between the opening portion 2a and the communication passage 2b. Further, the hole 6e that communicates the inner and outer sides of the shaft portion 62E is formed.
In the present modified example, when the opening and closing valve VL is at the second position, i.e., open position, as illustrated in FIG. 10, the high pressure refrigerant within the branch pipe DP is supplied via the piping portion 105Aa to the high pressure chamber HS, and the pressure of the refrigerant within the high pressure chamber HS is transmitted via the communication hole 2d, the pressure equalizing chamber EC, the gap between the second hole 63Eb and the actuation rod 5, and the through hole 63E to the cylinder chamber CS. By setting the internal pressure of the cylinder chamber CS to high pressure in a state where the lower end of the intermediate portion 64E of the syringe member 6E is abutted against the stepped portion 2Em between the opening portion 2Ea and the communication passage 2Eb, the transmission of driving force of the stopper member 84E that pushes the actuation rod 5 downward is interrupted, such that the valve element 3 is urged upward by the urging force of the urging device 4 and seated on the valve seat 20, and a forcible valve closed state is maintained regardless of the pressure difference between the pressure working chamber PA and the lower space LS.
Meanwhile, when the opening and closing valve VL is set to the first position, i.e., closed position, the high pressure of the refrigerant within the branch pipe DP will not be transmitted to the high pressure chamber HS, and a portion of the refrigerant within the cylinder chamber CS gradually flows into the return flow passage 23 through the hole 6e formed on the shaft portion 62E. Thereby, the internal pressure of the cylinder chamber CS drops and the force that pushes up the stopper member 84E is eliminated, such that the pressing force from the diaphragm 83 may be transmitted to the upper end of the actuation rod 5, and the forcible valve closed state is cancelled.

(Fifth Modified Example)

FIG. 11 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1F according to a fifth modified example, and illustrates a state in which the expansion valve 1F is disposed within the refrigeration cycle 100A illustrated schematically.
According to the expansion valve 1F of the present modified example, only the shapes of a valve main body 2F and a syringe member 6F differ from the second modified example, and the other configurations are similar to the second embodiment, such that the common configurations are denoted with the same reference numbers and descriptions thereof are omitted.
The present modified example is a modified example of the second embodiment, adopting a dedicated flow passage and an opening and closing valve that are used for discharging the pressure within the cylinder chamber CS.
According to the valve main body 2F, a discharge passage EX that communicates the pressure equalizing chamber EC with the exterior is formed, an outer end of the discharge passage EX is connected via a second opening and closing valve, i.e., second valve device, VL2 and a piping, also referred to as an external flow passage portion, HT to an inlet side of the evaporator 103. In the present modified example, the discharge passage EX is included in the outflow passage. The other configurations are similar to the embodiment illustrated in FIG. 5, other than the syringe member 6F not including the hole 6e, such that the same descriptions are omitted.
In the expansion valve 1F, by opening the opening and closing valve VL while closing the second opening and closing valve VL2, the high pressure refrigerant is introduced into the pressure equalizing chamber EC, and thereby, the forcible valve closing operation may be realized. Meanwhile, by opening the second opening and closing valve VL2 while closing the opening and closing valve VL, the refrigerant will flow from the pressure equalizing chamber EC via the discharge passage EX and the piping HT to the evaporator 103, such that a normal operation of the expansion valve 1F may be realized.
According to the present modified example, the refrigerant may be flown speedily from the pressure equalizing chamber EC via the discharge passage EX and the piping HT, such that the expansion valve 1F may be transited smoothly from the forcible valve closing operation to normal operation.

(Sixth Modified Example)

FIG. 12 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1G in a refrigerant cycle 100G according to a sixth modified example.
According to the expansion valve 1G of the present modified example, only the point that a second piping HT2 that connects the piping portion 105Aa and an inlet side of the evaporator 103 and the second opening and closing valve VL2 that opens and closes the second piping HT2 are provided differs from the second embodiment, and the other configurations are similar to the second embodiment, such that the common configurations are denoted with the same reference numbers and descriptions thereof are omitted.
According to the present modified example, by opening the opening and closing valve VL while closing the second opening and closing valve VL2, the high pressure refrigerant is introduced into the pressure equalizing chamber EC via the high pressure chamber HS, and thereby, the forcible valve closing operation may be realized. Meanwhile, by opening the second opening and closing valve VL2 while closing the opening and closing valve VL, the refrigerant will flow from the pressure equalizing chamber EC via the high pressure chamber HS and the second piping HT2 to the evaporator 103.
According to the first embodiment, the second embodiment, and the respective modified examples, an example in which the locking member 85 that regulates movement of the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F with respect to the stopper member 84, 84D, or 84E is disposed on the stopper member 84, 84D, or 84E has been described. Alternatively, in another example, the locking member 85 may be disposed on the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F. According to one example of a configuration in which the locking member 85 is disposed on the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F, the locking member 85 is disposed on the outer circumference portion of the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F, and a projected portion that abuts against the locking member 85 may be disposed on the stopper member 84, 84D, or 84E. By having the projected portion abut against the locking member 85, the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F is prevented from moving further with respect to the stopper member 84, 84D, or 84E.
The locking member 85 is not limited to one that is provided separately from the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F and fixed threreto. In another example, the locking member 85 may be formed integrally with the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F. What is meant by integrally is that the stopper member and the locking member are formed as one member. That is, a portion of the syringe member 6, 6A, 6B, 6C, 6D, 6E, or 6F may constitute the locking member 85. The same applies to a configuration in which the locking member 85 is disposed on the stopper member 84, 84D, or 84E, in which the locking member 85 may be formed integrally with the stopper member 84, 84D, or 84E.
The present specification includes the following disclosures of the invention.

(First Aspect)

An expansion valve including:

a valve main body including a valve chamber and a valve seat;
a power element disposed on the valve main body and including a displacement portion configured displaceably;
a valve element disposed in the valve chamber;
a first urging device configured to urge the valve element toward the valve seat;
an actuation rod disposed at the valve main body and arranged between the displacement portion and the valve element, the actuation rod configured to drive the valve element by receiving displacement of the displacement portion;
a syringe member disposed at the valve main body, the syringe member configured to accommodate a portion of the actuation rod movably in an interior thereof, and to constitute a cylinder chamber that is extensible in a movement direction of the valve element between itself and the displacement portion;
a movement regulation portion that regulates movement of the syringe member toward the valve chamber; and
a supplying portion configured to supply a fluid within the valve chamber or a fluid on an upstream side of the valve chamber to the cylinder chamber.

(Second Aspect)

The expansion valve according to the first aspect, further including a discharging portion configured to discharge a pressure within the cylinder chamber to a downstream side of the valve chamber.

(Third Aspect)

The expansion valve according to the second aspect,

wherein the supplying portion includes:
- an inflow passage formed at the valve main body and configured to cause the fluid in the valve chamber or the fluid from an upstream side of the valve chamber to flow into the cylinder chamber, and
- a first valve device disposed on the inflow passage and configured to control the flow of the fluid into the cylinder chamber,
wherein the discharging portion includes an outflow passage through which the fluid in the cylinder chamber is flown out to a downstream side of the valve chamber,
wherein the outflow passage includes a portion of the inflow passage, and a branched passage that is branched from the portion of the inflow passage and communicates the portion and a downstream side of the valve chamber, and
wherein the first valve device also serves as a second valve device, the first valve device being configured to be switched between a state in which the inflow passage is opened and the outflow passage is closed and a state in which the outflow passage is opened and the inflow passage is closed.

(Fourth Aspect)

The expansion valve according to the third aspect,

wherein the inflow passage includes:
- a first hole formed on the valve main body and in which a portion of the syringe member on the valve chamber side is disposed,
- a second hole formed on the syringe member and through which the first hole and the cylinder chamber are communicated,
- a first flow passage portion formed at the valve main body and configured to communicate with the valve chamber or with an upstream side of the valve chamber,
- a second flow passage portion formed at the valve main body and configured to communicate with the first hole, and
- a connecting chamber formed at the valve main body and configured to be connected to the first flow passage portion and the second flow passage portion,
wherein the outflow passage includes:
- the second flow passage portion,
- the connecting chamber, and
- a third flow passage portion that communicates a downstream side of the valve chamber and the connecting chamber,
wherein the connecting chamber includes:
- a first communicating flow passage configured to communicate the first flow passage portion and the second flow passage portion, and
- a second communicating flow passage configured to communicate the second flow passage portion and the third flow passage portion,
wherein the first valve device includes a valve shaft member disposed in the connecting chamber, and a drive device configured to drive the valve shaft member, and
wherein the valve shaft member is configured to move between a second position in which the first flow passage portion and the second flow passage portion are communicated via the first communicating flow passage of the connecting chamber such that both the first flow passage portion and the second flow passage portion are not communicated with the third flow passage portion, and a first position in which the second flow passage portion and the third flow passage portion are communicated via the second communicating flow passage of the connecting chamber such that both the second flow passage portion and the third flow passage portion are not communicated with the first flow passage portion.

(Fifth Aspect)

The expansion valve according to the fourth aspect,
wherein the drive device includes:

a driving portion disposed at the valve main body and including a plunger, the driving portion configured to move the valve shaft member by the plunger between a one side and the other side of the first position and the second position, and
a second urging device disposed on the connecting chamber and configured to urge the valve shaft member from the other side toward the one side.

(Sixth Aspect)

The expansion valve according to the fifth aspect, further including

a valve seat member disposed in the connecting chamber between an opening of the first flow passage portion and an opening of the third flow passage portion, the valve seat member configured to prevent a flow of a fluid from the first flow passage portion to the third flow passage portion, configured to cover an opening of the second flow passage portion, and having a gap between itself and the opening of the third flow passage portion,
wherein the valve seat member includes a through hole that is formed to pass through in a movement direction of the plunger, and a relay passage configured to relay the through hole and the opening of the second flow passage portion,
wherein the valve shaft member includes a shaft portion that is arranged in the through hole and configured movably in an axial direction of the through hole, the shaft portion forming a flow passage between itself and an inner surface of the through hole, and a collar portion disposed on the shaft portion and arranged in the gap, the collar portion configured to abut against the valve seat member so as to cause an opening of the through hole not to be communicated with the connecting chamber, and
wherein a tip surface of the plunger is formed on a surface that is configured to abut against the valve shaft member so as to cause the opening of the through hole not to be communicated with the connecting chamber.

(Seventh Aspect)

The expansion valve according to the sixth aspect,

wherein a circumference of the opening of the through hole on an end surface of the valve seat member on the third flow passage portion side is formed by a first sealing member, and
wherein a circumference of the opening of the through hole on an end surface of the valve seat member on the driving portion side is formed by a second sealing member.

(Eighth Aspect)

The expansion valve according to any one of the first to seventh aspects,
wherein the supplying portion includes:

an inflow passage disposed at the valve main body and connected to an external flow passage portion on an upstream side of the valve chamber outside the valve main body, the inflow passage causing the fluid on an upstream side of the valve chamber to flow into the cylinder chamber, and
a valve device disposed on the inflow passage or the external flow passage portion, the valve device configured to control a flow of the fluid flowing into the cylinder chamber via the inflow passage.

(Ninth Aspect)

The expansion valve according to any of the second to eight aspects,
wherein the discharging portion includes:

an outflow passage disposed at the valve main body and connected to an external flow passage portion on a downstream side of the valve chamber outside the valve main body, the outflow passage causing the fluid in the cylinder chamber to flow out via the external flow passage portion to a downstream side of the valve chamber, and
a valve device disposed on the outflow passage or the external flow passage portion, the valve device configured to control outflow of the fluid in the cylinder chamber via the outflow passage to the downstream side of the valve chamber.

(Tenth Aspect)

The expansion valve according to the first aspect,

wherein the valve main body includes a low-pressure flow passage through which a fluid having a lower pressure than a pressure within the valve chamber flows,
wherein the power element includes:
- a housing fixed to the valve main body,
- a diaphragm disposed within the housing and partitioning an inside of the housing into a pressure working chamber and a valve-chamber-side chamber communicated with the low-pressure flow passage,
- a stopper member disposed in the valve-chamber-side chamber and serving as the displacement portion, and
- a locking portion disposed on either one of the stopper member and the syringe member,
wherein the syringe member is disposed on an inner side of the stopper member, or the stopper member is disposed on an inner side of the syringe member, and
wherein the locking portion prevents the syringe member from falling out of the stopper member or the stopper member from falling out of the syringe member by abutting against the other one of the stopper member or the syringe member.

(Eleventh Aspect)

The expansion valve according to any one of the first to tenth aspects,

further including a flange portion in which a lower end of the housing is extended toward an inner side,
wherein the syringe member includes a shaft portion configured to pass through an inner side of the flange portion, and a base portion that is disposed on an end portion of the shaft portion on the power element side, the base portion having a larger dimension than the shaft portion,
wherein the base portion has a dimension facing the flange portion in a movement direction of the shaft portion,
wherein, in a state where a movement of the syringe member with respect to the stopper member is regulated by the locking portion, an end surface of the base portion on the valve chamber side is positioned on the valve chamber side than an end surface of the stopper member on the valve chamber side, and
wherein the flange portion and the base portion constitute the movement regulation portion.

(Twelfth Aspect)

The expansion valve according to any one of first to tenth aspects,

wherein the syringe member includes a shaft portion, and a base portion disposed on one end of the shaft portion serving as the power element side, the base portion configured to have a larger diameter than the shaft portion in a direction orthogonal to an axis of the shaft portion,
wherein the valve main body includes a hole configured to have the syringe member arranged movably therein, and
wherein the other end of the shaft portion and a bottom surface of an inner space of the hole, or the base portion and a surface of the valve main body facing the base portion, constitute the movement regulation portion.

(Thirteenth Aspect)

The expansion valve according to any one of the first to twelfth aspects,

wherein the syringe member includes a base portion having a tubular shape, and a shaft portion connected to the base portion,
wherein the displacement portion is fit slidably to an inner circumference of the base portion,
wherein the shaft portion is passed through an opening portion of the valve main body having a dimension smaller than the base portion, and
wherein the movement regulation portion is formed by a circumference of the opening portion.

(Fourteenth Aspect)

The expansion valve according to any one of the first to thirteenth aspects,

wherein the valve main body includes a low-pressure flow passage through which fluid of a lower pressure than a pressure within the valve chamber flows,
wherein the power element includes:
- a housing fixed to the valve main body,
- a diaphragm disposed within the housing, the diaphragm partitioning an inside of the housing into a pressure working chamber and a valve chamber-side chamber communicated with the low-pressure flow passage, and
- a stopper member disposed in the valve chamber-side chamber,
wherein the displacement portion is the stopper member, and
wherein the diaphragm deforms according to a pressure difference between the pressure working chamber and the valve chamber-side chamber, and wherein the stopper member is configured displaceably according to the deformation of the diaphragm.

[Reference Signs List]

1, 1A, 1B, 1C, 1D, 1E, 1F, 1G: expansion valve
2, 2A, 2B, 2C, 2E, 2F: valve main body
3: valve element
4: urging device
5: actuation rod
6, 6A, 6B, 6C, 6D, 6E, 6F: syringe member
8, 8E: power element
20: valve seat
140: attraction element
135: plunger
132: coil
EV: electromagnetic valve
VS: valve chamber
VL: opening and closing valve
VL2:second opening and closing valve
CS: cylinder chamber
HS: high pressure chamber

Claims

An expansion valve comprising:
a valve main body including a valve chamber and a valve seat;

a power element disposed on the valve main body and including a displacement portion configured displaceably;

a valve element disposed in the valve chamber;

a first urging device configured to urge the valve element toward the valve seat;

an actuation rod disposed at the valve main body and arranged between the displacement portion and the valve element, the actuation rod configured to drive the valve element by receiving displacement of the displacement portion;

a syringe member disposed at the valve main body, the syringe member configured to accommodate a portion of the actuation rod movably in an interior thereof, and to constitute a cylinder chamber that is extensible in a movement direction of the valve element between itself and the displacement portion;

a movement regulation portion configured to regulate movement of the syringe member toward the valve chamber; and

a supplying portion configured to supply a fluid within the valve chamber or a fluid on an upstream side of the valve chamber to the cylinder chamber.
The expansion valve according to claim 1, further comprising a discharging portion configured to discharge a pressure within the cylinder chamber to a downstream side of the valve chamber.
The expansion valve according to claim 2,
wherein the supplying portion includes:
an inflow passage formed at the valve main body and configured to cause the fluid in the valve chamber or the fluid from an upstream side of the valve chamber to flow into the cylinder chamber, and

a first valve device disposed on the inflow passage and configured to control the flow of the fluid into the cylinder chamber,

wherein the discharging portion includes an outflow passage through which the fluid in the cylinder chamber is flown out to a downstream side of the valve chamber,

wherein the outflow passage includes a portion of the inflow passage, and a branched passage that is branched from the portion of the inflow passage and communicates the portion and a downstream side of the valve chamber, and

wherein the first valve device also serves as a second valve device, the first valve device being configured to be switched between a state in which the inflow passage is opened and the outflow passage is closed and a state in which the outflow passage is opened and the inflow passage is closed.
The expansion valve according to claim 3,
wherein the inflow passage includes:
a first hole formed on the valve main body and in which a portion of the syringe member on the valve chamber side is disposed,

a second hole formed on the syringe member and through which the first hole and the cylinder chamber are communicated,

a first flow passage portion formed at the valve main body and configured to communicate with the valve chamber or with an upstream side of the valve chamber,

a second flow passage portion formed at the valve main body and configured to communicate with the first hole, and

a connecting chamber formed at the valve main body and configured to be connected to the first flow passage portion and the second flow passage portion,

wherein the outflow passage includes:
the second flow passage portion,

the connecting chamber, and

a third flow passage portion that communicates a downstream side of the valve chamber and the connecting chamber,

wherein the connecting chamber includes:
a first communicating flow passage configured to communicate the first flow passage portion and the second flow passage portion, and

a second communicating flow passage configured to communicate the second flow passage portion and the third flow passage portion,

wherein the first valve device includes a valve shaft member disposed in the connecting chamber, and a drive device configured to drive the valve shaft member, and

wherein the valve shaft member is configured to move between a second position in which the first flow passage portion and the second flow passage portion are communicated via the first communicating flow passage of the connecting chamber such that both the first flow passage portion and the second flow passage portion are not communicated with the third flow passage portion, and a first position in which the second flow passage portion and the third flow passage portion are communicated via the second communicating flow passage of the connecting chamber such that both the second flow passage portion and the third flow passage portion are not communicated with the first flow passage portion.
The expansion valve according to claim 4,
wherein the drive device includes:
a driving portion disposed at the valve main body and including a plunger, the driving portion configured to move the valve shaft member by the plunger between a one side and the other side of the first position and the second position, and

a second urging device disposed on the connecting chamber and configured to urge the valve shaft member from the other side toward the one side.
The expansion valve according to claim 5, further comprising
a valve seat member disposed in the connecting chamber between an opening of the first flow passage portion and an opening of the third flow passage portion, the valve seat member configured to prevent a flow of a fluid from the first flow passage portion to the third flow passage portion, configured to cover an opening of the second flow passage portion, and having a gap between itself and the opening of the third flow passage portion,

wherein the valve seat member includes a through hole that is formed to pass through in a movement direction of the plunger, and a relay passage configured to relay the through hole and the opening of the second flow passage portion,

wherein the valve shaft member includes a shaft portion that is arranged in the through hole and configured movably in an axial direction of the through hole, the shaft portion forming a flow passage between itself and an inner surface of the through hole, and a collar portion disposed on the shaft portion and arranged in the gap, the collar portion configured to abut against the valve seat member so as to cause an opening of the through hole not to be communicated with the connecting chamber, and

wherein a tip surface of the plunger is formed on a surface that is configured to abut against the valve shaft member so as to cause the opening of the through hole not to be communicated with the connecting chamber.
The expansion valve according to claim 6,
wherein a circumference of the opening of the through hole on an end surface of the valve seat member on the third flow passage portion side is formed by a first sealing member, and

wherein a circumference of the opening of the through hole on an end surface of the valve seat member on the driving portion side is formed by a second sealing member.
The expansion valve according to claim 1,
wherein the supplying portion includes:
an inflow passage disposed at the valve main body and connected to an external flow passage portion on an upstream side of the valve chamber outside the valve main body, the inflow passage causing the fluid on an upstream side of the valve chamber to flow into the cylinder chamber, and

a valve device disposed on the inflow passage or the external flow passage portion, the valve device configured to control a flow of the fluid flowing into the cylinder chamber via the inflow passage.
The expansion valve according to claim 2,
wherein the discharging portion includes:
an outflow passage disposed at the valve main body and connected to an external flow passage portion on a downstream side of the valve chamber outside the valve main body, the outflow passage causing the fluid in the cylinder chamber to flow out via the external flow passage portion to a downstream side of the valve chamber, and

a valve device disposed on the outflow passage or the external flow passage portion, the valve device configured to control outflow of the fluid in the cylinder chamber via the outflow passage to the downstream side of the valve chamber.
The expansion valve according to claim 1,
wherein the valve main body includes a low-pressure flow passage through which a fluid having a lower pressure than a pressure within the valve chamber flows,

wherein the power element includes:
a housing fixed to the valve main body,

a diaphragm disposed within the housing and partitioning an inside of the housing into a pressure working chamber and a valve-chamber-side chamber communicated with the low-pressure flow passage,

a stopper member disposed in the valve-chamber-side chamber and serving as the displacement portion, and

a locking portion disposed on either one of the stopper member and the syringe member,

wherein the syringe member is disposed on an inner side of the stopper member, or the stopper member is disposed on an inner side of the syringe member, and

wherein the locking portion prevents the syringe member from falling out of the stopper member or the stopper member from falling out of the syringe member by abutting against the other one of the stopper member or the syringe member.
The expansion valve according to claim 10,
further comprising a flange portion in which a lower end of the housing is extended toward an inner side,

wherein the syringe member includes a shaft portion configured to pass through an inner side of the flange portion, and a base portion that is disposed on an end portion of the shaft portion on the power element side, the base portion having a larger dimension than the shaft portion,

wherein the base portion has a dimension facing the flange portion in a movement direction of the shaft portion,

wherein, in a state where a movement of the syringe member with respect to the stopper member is regulated by the locking portion, an end surface of the base portion on the valve chamber side is positioned on the valve chamber side than an end surface of the stopper member on the valve chamber side, and

wherein the flange portion and the base portion constitute the movement regulation portion.
The expansion valve according to claim 1,
wherein the syringe member includes a shaft portion, and a base portion disposed on one end of the shaft portion serving as the power element side, the base portion configured to have a larger diameter than the shaft portion in a direction orthogonal to an axis of the shaft portion,

wherein the valve main body includes a hole configured to have the syringe member arranged movably therein, and

wherein the other end of the shaft portion and a bottom surface of an inner space of the hole, or the base portion and a surface of the valve main body facing the base portion, constitute the movement regulation portion.
The expansion valve according to claim 1,
wherein the syringe member includes a base portion having a tubular shape, and a shaft portion connected to the base portion,

wherein the displacement portion is fit slidably to an inner circumference of the base portion,

wherein the shaft portion is passed through an opening portion of the valve main body having a dimension smaller than the base portion, and

wherein the movement regulation portion is formed by a circumference of the opening portion.
The expansion valve according to claim 1,
wherein the valve main body includes a low-pressure flow passage through which fluid of a lower pressure than a pressure within the valve chamber flows,

wherein the power element includes:
a housing fixed to the valve main body,

a diaphragm disposed within the housing, the diaphragm partitioning an inside of the housing into a pressure working chamber and a valve chamber-side chamber communicated with the low-pressure flow passage, and

a stopper member disposed in the valve chamber-side chamber, wherein the displacement portion is the stopper member, and

wherein the diaphragm deforms according to a pressure difference between the pressure working chamber and the valve chamber-side chamber, and wherein the stopper member is configured displaceably according to the deformation of the diaphragm.