Expansion valve

Abstract

To provide an expansion valve which arbitrarily secure a valve-closing state by using the fluid pressure of a refrigeration cycle.SOLUTION: An expansion valve comprises: a valve main body having a valve chamber and a valve seat; a power element arranged at the valve main body, and having a displaceable displacement part; a valve body arranged in the valve chamber; a first energization device for energizing the valve body toward the valve seat; a working rod provided in the valve body, arranged between the displacement part and the valve body, and driving the valve body by receiving a displacement of the displacement part; a syringe member for constituting a cylinder chamber which is provided in the valve main body, movably accommodates a part of the working rod therein, and is telescopic in a moving direction of the valve body between the displacement part and itself; a movement regulation part for regulating the movement of the syringe member to the valve chamber side; and a supply part for supplying fluid in the valve chamber, or fluid on the upstream side of the valve chamber into the cylinder chamber.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an expansion valve. [Background technology]

[0002] As one type of expansion valve, an expansion valve equipped with a solenoid valve is known. This type of expansion valve is applied to, for example, a refrigeration cycle having a plurality of evaporators connected in parallel, and has a function of controlling the degree of superheat of the refrigerant on the outlet side of the evaporators as well as a function of shutting off the circuit in the refrigeration cycle.

[0003] Patent Document 1 discloses an expansion valve having a valve port provided in a communication passage connecting a primary passage into which high-pressure refrigerant flows and a valve chest, and having a solenoid valve attached for opening and closing the valve port. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3362990 Summary of the Invention [Problem to be solved by the invention]

[0005] According to the configuration of Patent Document 1, the expansion valve can be operated by opening the valve port using the solenoid valve, and the expansion valve can be forcibly closed by closing the valve port.

[0006] However, in the expansion valve of Patent Document 1, the solenoid valve and the expansion valve are connected in series, which means that the refrigerant that enters the primary passage must pass through two orifices, the solenoid valve orifice and the expansion valve orifice, before flowing out of the expansion valve, which leads to an increase in pressure loss.

[0007] The present invention has been made in consideration of the above problems, and has an object to provide an expansion valve that can arbitrarily maintain a closed state by utilizing the fluid pressure of a refrigeration cycle. [Means for solving the problem]

[0008] The solenoid valve of the present invention comprises: a valve body having a valve chamber and a valve seat; a power element provided in the valve body and having a displaceable displacement portion; a valve body disposed in the valve chamber; a first biasing device that biases the valve body toward the valve seat; an actuating rod that is provided in the valve body, disposed between the displacement portion and the valve body, and drives the valve body in response to displacement of the displacement portion; a syringe member provided in the valve body, movably housing a portion of the actuation rod therein, and defining a cylinder chamber between the syringe member and the displacement portion that is expandable and contractable in the movement direction of the valve body; a movement restriction portion that restricts movement of the syringe member toward the valve chamber; a supply unit that supplies the fluid in the valve chamber or the fluid upstream of the valve chamber to the cylinder chamber. It is characterized by: Effect of the Invention

[0009] According to the present invention, it is possible to provide an expansion valve that can maintain a closed state at will by utilizing the fluid pressure of a refrigeration cycle. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an open state of an expansion valve in a first embodiment. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the expansion valve in a cross section shifted in phase by 90 degrees around the axis L from FIG. [Diagram 3] 3 is an enlarged cross-sectional view showing the solenoid valve shown in FIG. 2 and its periphery. [Figure 4]FIG. 4 is a vertical cross-sectional view similar to that of FIG. 2, showing the expansion valve in a closed state. [Diagram 5] FIG. 5 is a vertical cross-sectional view showing an open state of an expansion valve in the second embodiment. [Figure 6] FIG. 6 is a vertical cross-sectional view showing the expansion valve in the closed state according to the second embodiment. [Figure 7] FIG. 7 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a first modified example. [Figure 8] FIG. 8 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a second modified example. [Figure 9] FIG. 9 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a third modified example. [Figure 10] FIG. 10 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a fourth modified example. [Figure 11] FIG. 11 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a fifth modified example. [Figure 12] FIG. 12 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve according to a sixth modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] (First embodiment) The structure of an expansion valve 1 according to a first embodiment will be described below with reference to FIG. Fig. 1 is a schematic cross-sectional view of an expansion valve 1 in an open state in this embodiment, and shows a refrigeration cycle 100 to which this is connected. Fig. 2 is a longitudinal cross-sectional view of the expansion valve 1 in a cross section shifted in phase by 90 degrees around the axis L from Fig. 1, showing the open state. Fig. 3 is a cross-sectional view showing an enlarged view of the periphery of the solenoid valve EV shown in Fig. 2. Fig. 4 is a longitudinal cross-sectional view of the expansion valve 1 in a cross section similar to Fig. 2, showing the closed state. In addition, "upstream of the valve chamber" refers to the side closer to the condenser than the valve chamber, and "downstream of the valve chamber" refers to the side closer to the evaporator than the valve chamber.

[0012] The expansion valve 1 includes a valve body 2 having a valve chamber VS, a valve element 3, a biasing device (also referred to as a first biasing device) 4, an actuating rod 5, a syringe member 6, and a power element 8. The axis of the expansion valve 1 is designated as L. Here, along the axis L, the power element 8 side is the upper side, and the biasing device 4 side is the lower side.

[0013] The valve body 2 includes a valve chamber VS, as well as a first flow path 21, a second flow path 22, and a return flow path (low pressure flow path) 23. The first flow path 21 is a supply side flow path, and a refrigerant (also referred to as fluid) is supplied to the valve chamber VS via the supply side flow path. The second flow path 22 is a discharge side flow path, and the fluid in the valve chamber VS is discharged to the outside of the expansion valve via the working rod insertion hole 27, the intermediate passage 22a, and the discharge side flow path. The first flow path 21 and the valve chamber VS are in communication via a small diameter passage 21a.

[0014] The spherical valve element 3 is disposed in the valve chamber VS. When the valve element 3 is seated on the annular valve seat 20 of the valve body 2, the valve chamber VS is not in communication with the second flow passage 22. On the other hand, when the valve element 3 is separated from the valve seat 20, the valve chamber VS is in communication with the second flow passage 22.

[0015] The actuating rod 5 is inserted into the actuating rod insertion hole 27 of the valve body 2 with a gap therebetween, and is guided by the central hole 28 and held so as to be displaceable in the direction of the axis L. The lower end of the actuating rod 5 contacts the upper surface of the valve body 3, and the upper end of the actuating rod 5 abuts against the lower surface of the stopper member 84 of the power element 8.

[0016] The actuating rod 5 can press the valve element 3 in the valve opening direction against the biasing force of the biasing device 4. When the actuating rod 5 moves toward the valve element, the valve element 3 moves away from the valve seat 20, and the expansion valve 1 is in the open state.

[0017] The syringe member 6 arranged around the actuation rod 5 is provided in the valve body 2, movably accommodates a part of the actuation rod 5 therein, and forms a cylinder chamber between the stopper member 84 and the syringe member 6 that can expand and contract in the moving direction of the valve body 3. The syringe member 6 is composed of a disk base (also simply called a base) 61 on the upper end side and a shaft (also called a syringe member shaft) 62 on the lower end side that are coaxially connected, and has a through hole 63 that penetrates from the upper end side to the lower end. The through hole 63 has a first hole 63a on the upper end side and a second hole 63b on the lower end side. The second hole 63b has an inner diameter smaller than that of the first hole 63a, and is slidably fitted to the outer periphery of the actuation rod 5.

[0018] The disk base 61 is housed in a cylindrical recess 84a of a stopper member 84 (described later) of the power element 8. A first circumferential groove 61a is formed on the outer periphery of the disk base 61, and a first O-ring OR1 is disposed therein to provide a seal between the cylindrical recess 84a and the disk base 61.

[0019] A second circumferential groove 62a is formed on the outer periphery of the shaft portion 62 near the lower end thereof, and a second O-ring OR2 is disposed inside the second circumferential groove 62a to provide a seal between the enlarged diameter hole (first hole) 26 of the valve body 2 and the shaft portion 62. The shaft portion 62 is slidably fitted into the enlarged diameter hole 26.

[0020] A thin-diameter portion 62b is formed on the outer periphery of the lower end of the shaft portion 62 below the second circumferential groove 62a, and the outer diameter of the thin-diameter portion 62b is smaller than the outer diameter of the shaft portion 62 other than the thin-diameter portion 62b. A connection hole 62d is formed in the thin-diameter portion 62b, penetrating between its inner periphery and outer periphery. Since the expanded diameter hole 26 has a substantially uniform inner diameter, there is a gap between the outer periphery of the reduced diameter portion 64 and the inner periphery of the expanded diameter hole 26.

[0021] Between the enlarged diameter hole 26 and the central hole 28 of the valve body 2, a medium diameter hole 29 having a diameter smaller than the enlarged diameter hole 26 and larger than the central hole 28 is formed. A third O-ring OR3, through which the actuating rod 5 passes, is disposed in the medium diameter hole 29 to provide a seal between the actuating rod 5 and the medium diameter hole 29.

[0022] Here, the space between the enlarged diameter hole 26 and the medium diameter hole 29, which are sealed by the second O-ring OR2 and the third O-ring OR3, is defined as a pressure equalizing chamber (also called a pressure equalizing space) EC. A communication hole 2d is formed in the valve body 2, extending downward from the enlarged diameter hole 26 facing the pressure equalizing chamber EC at an angle with respect to the axis L (see FIG. 2).

[0023] The syringe member 6 extends along the axis L from the power element 8, via the communicating passage 2b, the return flow path 23, and the enlarged diameter hole 26 formed in the valve body 2, to the step 26a between the enlarged diameter hole 26 and the medium diameter hole 29.

[0024] Next, the power element 8 will be described. The power element 8 is attached to an opening 2a provided at the top of the valve body 2. The opening 2a communicates with a return flow passage 23 through which the refrigerant from the evaporator passes via a communication passage 2b.

[0025] The power element 8 has a plug 81, an upper cover member 82, a diaphragm 83, a stopper member 84 constituting a displacement portion, and a receiving member 86.

[0026] A hole 82 a is formed in the top of the upper cover member 82 , and can be sealed with a plug 81 .

[0027] The diaphragm 83 is made of, for example, a thin plate material on which a plurality of concentric circular projections and recesses are formed.

[0028] The stopper member 84, which is substantially cylindrical with a top, has a disk portion 84b and a circular tube portion 84c coaxially connected to the lower surface of the disk portion 84b, and the inside of the circular tube portion 84c is a cylindrical recess 84a. An annular locking member (also called a locking portion) 85 is attached to the inner peripheral step at the lower end of the circular tube portion 84c. After the disk base portion 61 of the syringe member 6 is inserted into the cylindrical recess 84a, a crimping portion 84d at the lower end of the circular tube portion 84c disposed on the outer periphery of the locking member 85 is crimped radially inward to attach the locking member 85 to the circular tube portion 84c, thereby preventing the disk base portion 61 from coming off the stopper member 84.

[0029] That is, by abutting against the syringe member 6, the locking member 85 prevents the syringe member 6 from moving beyond a predetermined position toward the valve chamber side relative to the stopper member 84. In other words, the locking member 85 prevents the syringe member 6 from slipping out of the stopper member 84. Note that, although an example has been described in which the portion of the stopper member 84 that abuts against the syringe member 6 is formed separately as the locking member 85, the portion of the stopper member 84 that abuts against the syringe member 6 may be formed integrally with the stopper member 84.

[0030] The disk base 61 is displaceable in the axial direction between an upper position where its upper end abuts against the lower surface of the disk portion 84b (abutment position where it abuts against the stopper member 84: FIG. 2) and a lower position where its lower end abuts against the upper surface of the locking member 85. However, in the assembled state of the expansion valve 1, the shaft portion 62 abuts against a step portion (also referred to as a bottom surface of the hole) 26a between the enlarged diameter hole 26 and the medium diameter hole 29 before the disk base 61 abuts against the locking member 85. In other words, the step portion of the medium diameter hole 29 functions as a movement restricting portion that restricts the movement of the syringe member 6 toward the valve chamber VS. Therefore, in the closed valve state, the axial dimension of the syringe member 6 is set so that the lower end of the shaft portion 62 abuts against the step portion 26a between the enlarged diameter hole 26 and the medium diameter hole 29 (the abutting position against the valve body 2: Figure 4), and the disk base 61 is spaced from the underside of the disk portion 84b of the stopper member 84.

[0031] Here, the space between the disk portion 84b and the disk base 61 is defined as a cylinder chamber CS. The cylinder chamber CS communicates only with the through-hole 63. An annular recess 84e is formed in the lower surface of the disk portion 84b so as to face the outer periphery of the upper end of the disk base 61, and the inside of the annular recess 84e forms a part of the cylinder chamber CS.

[0032] The receiving member 86 has a flange portion having an outer diameter substantially the same as that of the upper cover member 82, and a hollow cylindrical portion connected to the lower end of the flange portion, and a male thread 86c is formed on the outer periphery of the hollow cylindrical portion.

[0033] When assembling the power element 8, the outer peripheries of the upper cover member 82, the diaphragm 83, and the flange portion of the receiving member 86 are overlapped with each other while the stopper member 84 is placed inside, and the outer peripheries are circumferentially welded by, for example, TIG welding, laser welding, plasma welding, or the like to form a housing. At this time, the syringe member 6 may be assembled in advance inside the stopper member 84, or the syringe member 6 may be assembled after welding.

[0034] Next, working gas is injected into the space surrounded by the upper cover member 82 and the diaphragm 83 (called the pressure actuated chamber PA) through the hole 82a formed in the upper cover member 82, and then the hole 82a is sealed with a plug 81, and the plug 81 is fixed to the upper cover member 82 using projection welding or the like.

[0035] At this time, the diaphragm 83 is pressurized by the working gas sealed in the pressure actuated chamber PA in such a way that it bulges towards the receiving member 86, and is supported by abutting against the upper surface of the stopper member 84 disposed in the lower space (valve-chamber side chamber) LS surrounded by the diaphragm 83 and the receiving member 86. Note that, since the disk portion 84b of the stopper member 84 is held by the receiving member 86, the stopper member 84 will not come out of the power element 8.

[0036] When assembling the power element 8 to the valve body 2, after inserting the actuating rod 5 into the valve body 2, the syringe member 6 together with the stopper member 84 is inserted into the valve body 2 from its lower end side, and the second hole 63b is fitted onto the actuating rod 5. Furthermore, the male thread 86c of the receiving member 86 is screwed into the female thread of the opening 2a of the valve body 2, and the power element 8 is fixed to the valve body 2 by screwing it in. The gap between the valve body 2 and the power element 8 is sealed by a packing PK. In this state, the lower space LS of the power element 8 communicates with the return flow path 23, i.e., they have the same internal pressure.

[0037] Next, the biasing device 4 will be described. In Fig. 1, the biasing device 4 has a coil spring 41 made of a circular wire wound in a spiral shape, a valve element support 42 attached to the upper end of the coil spring 41 to support the valve element 3, a spring receiving member 43 attached to the valve body 2 while supporting the lower end of the coil spring 41, and a vibration-proof member 44 sandwiched between the valve element support 42 and the coil spring 41. The spring receiving member 43 seals the valve chamber VS of the valve body 2, and has the function of supporting the end of the coil spring 41 that biases the valve element 3 toward the valve seat 20.

[0038] The spherical valve element 3 is welded to the upper surface of the valve element support 42, and the two are integrated together. The vibration-proof member 44 has, for example, a claw portion protruding in the radial direction elastically engaged with the inner periphery of the valve chamber VS, and has the function of suppressing vibration of the valve element 3. Note that the vibration-proof member 44 is described in detail in, for example, JP 2018-025331 A, and therefore a detailed description thereof will be omitted.

[0039] (Solenoid valve structure) Next, the structure of the solenoid valve EV of this embodiment will be described with reference to Figures 2 and 3. The solenoid valve EV is a first valve device and a second valve device, or a drive unit, that can switch between a state in which the inflow path is open and the outflow path is closed, and a state in which the outflow path is open and the inflow path is closed. The inflow path and the solenoid valve EV constitute a supply unit and a discharge unit. The axis of the solenoid valve EV is O. The axis O is perpendicular to the axis L.

[0040] 2, the valve body 2 is formed with a circular large opening 2e that opens outward along the axis O, a middle opening 2f with a smaller diameter than the large opening 2e, and a small opening 2g with a smaller diameter than the middle opening 2f. The bottom of the large opening 2e communicates with the valve chamber VS through an inlet hole 2h. A communication hole 2d opens on the inner circumference at the middle position of the middle opening 2f. Furthermore, the bottom of the small opening 2g communicates with the intermediate passage 22a through an outlet hole (also called a connection path) 2j.

[0041] The inlet hole 2h, the high pressure chamber HS, the intermediate opening 2f, the communicating hole 2d, the enlarged diameter hole 26, the connecting hole 62d, and the through hole 63 form an inflow path, the connecting hole 62d and the through hole 63 form a second hole, the inlet hole 2h forms a first flow path portion, and the communicating hole 2d forms a second flow path portion.

[0042] The through hole 63, the connection hole 62d, the enlarged diameter hole 26, the communication hole 2d, the medium opening 2f, the small opening 2g, and the outlet hole 2j form an outflow path. The small opening 2g and the outlet hole 2j form a branch flow path, the outlet hole 2j forms a third flow path portion, and the high pressure chamber HS, the medium opening 2f, and the small opening 2g form a connecting chamber. The intermediate passage 22a forms a downstream flow path downstream of the valve seat 20.

[0043] 3, a cylindrical valve seat member 112 is disposed in the middle opening 2f, and is fixed to the middle opening 2f by crimping a cylindrical crimping portion 2i formed at the bottom of the large opening (also called a recess) 2e radially inward. As described later, the valve seat member 112 is disposed between the opening of the first flow path portion and the opening of the third flow path portion in the connecting chamber to prevent the flow of the refrigerant from the first flow path portion to the third flow path portion, covers the opening of the second flow path portion, and forms a gap between the opening of the third flow path portion and the valve seat member 112.

[0044] The valve seat member 112 has a through hole (also called a through hole) 112a extending along the axis O, a circumferential groove 112b formed around the entire circumference at a middle position in the direction of the axis O, a radial hole 112c that radially connects the through hole 112a and the circumferential groove 112b, and a recess 112d formed at the end on the small opening 2g side. The circumferential groove 112b communicates with the communication hole 2d. The circumferential groove 112b and the radial hole 112c form a relay path. Here, a part of the high pressure chamber HS, the through hole 112a, the radial hole 112c, and the circumferential groove 112b of the valve seat member 112 form a first communication flow path, and the through hole 112a, the radial hole 112c, the circumferential groove 112b, and the small opening 2g of the valve seat member 112 form a second communication flow path.

[0045] A first annular seal member SL1 is attached by adhesion or the like within the recess 112d of the valve seat member 112, and a second annular seal member SL2 is attached by adhesion or the like to the end opposite the recess 112d. The inner diameters of the first seal member SL1 and the second seal member SL2 are approximately equal to the inner diameter of the through hole 112a. The first seal member SL1 abuts against a step at the boundary between the middle opening 2f and the small opening 2g, and the second seal member SL2 abuts against the inner circumference of the middle opening 2f, thereby providing a seal between the valve seat member 112 and the valve body 2.

[0046] The cylindrical valve shaft member 113 has a long shaft portion (also simply referred to as a shaft portion) 113a inserted so as to penetrate the through hole 112a of the valve seat member 112 and the first and second seal members SL1 and SL2, a flange portion (also referred to as a flange portion) 113b having a diameter larger than that of the through hole 112a, and a short shaft portion 113c. Between the outer periphery of the long shaft portion 113a and the inner periphery of the through hole 112a, the first and second seal members SL1 and SL2, there are gaps through which the refrigerant can pass, and the valve shaft member 113 is movable relative to the valve seat member 112 in the direction of the axis O. Specifically, the valve shaft member 113 is movable between a second position in which the first flow path portion and the second flow path portion are connected via the first connecting flow path of the connecting chamber, and both the first flow path portion and the second flow path portion are not connected to the third flow path portion, and a first position in which the second flow path portion and the third flow path portion are connected via the second connecting flow path of the connecting chamber, and both the second flow path portion and the third flow path portion are not connected to the first flow path portion.

[0047] A compression spring (also called a second biasing device) 114 is disposed around the short shaft portion 113c between the bottom of the small opening 2g and the opposing surface of the flange portion 113b, and biases the valve shaft member 113 toward the large opening 2e with respect to the bottom of the small opening 2g. The solenoid valve EV and the compression spring 114 constitute a drive device.

[0048] The solenoid valve EV comprises an annular base 120, a coil 132 for energizing, a yoke 133, a pipe 141 arranged on the inner periphery of the yoke 133 and extending in the direction of axis O, a plunger (displacement member) 135 arranged on the inner periphery of the pipe 141 so as to be able to slide freely in the direction of axis O, an attractor 140 fixedly arranged on the inner periphery of the end of the pipe 141, and a housing 138 arranged to cover these.

[0049] An end of the pipe 141 is fixed to the inner periphery of the base 120 by press-fitting or brazing, and the base 120 is fixed to the valve body 2 by screwing a male thread 121 formed on the outer periphery of the base 120 into a female thread 2k formed on the inner periphery of the large opening 2e of the valve body 2. An O-ring OR4 is disposed between the bottom of the large opening 2e and the base 120 to seal between the base 120 and the valve body 2. This forms a high pressure chamber HS between the base 120 and the large opening 2e. The high pressure chamber HS communicates with the inlet hole 2h and can also communicate with the through hole 112a of the valve seat member 112.

[0050] An internal thread portion 142 is formed on the end face of the suction element 140 opposite to the pipe 141. With the housing 138 interposed therebetween, the suction element 140 and the housing 138 are joined by screwing a mounting bolt 137 into the internal thread portion 142. The housing 138 is fixed to the base 120 via a spacer 139.

[0051] The cylindrical plunger 135 is made of a magnetic material and is formed by connecting an enlarged diameter cylinder portion 135a and a reduced diameter cylinder portion 135b having a diameter larger than the inner diameter of the through hole 112a. A circular recess 135c is formed at the end of the reduced diameter cylinder portion 135b, into which the end of the long shaft portion 113a of the valve shaft member 113 exposed from the valve seat member 112 is loosely fitted (i.e., relatively displaceable in the direction of the axis O). The plunger 135 is biased toward the valve seat member 112 by a compression coil spring 136 compressed between the plunger 135 and the attractor 140. The tip surface of the plunger 135 is formed into a surface that, by abutting against the valve shaft member 113, makes the opening of the through hole 112a and the connection chamber non-communicative.

[0052] (Expansion valve operation) An example of operation when the expansion valve 1 is incorporated in a refrigeration cycle 100 will be described with reference to Fig. 1. A refrigerant pressurized by a compressor 101 in the refrigeration cycle 100 is liquefied by a condenser 102 and sent to the expansion valve 1. The refrigerant adiabatically expanded by the expansion valve 1 is sent to an evaporator 103 of the refrigeration cycle 100 and exchanges heat with air flowing around the evaporator 103. The refrigerant returning from the evaporator 103 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return flow path 23).

[0053] 2, it is assumed that the plunger 135 of the solenoid valve EV is in a first position (described later). In the first position, the pressure of the refrigerant in the cylinder chamber CS becomes substantially equal to the pressure in the intermediate passage 22a (and the return passage 23), as described later. This allows the stopper member 84 to approach the syringe member 6, and therefore the operating rod 5 is driven according to the deformation of the diaphragm 83, and the expansion valve 1 can perform its normal valve opening operation.

[0054] A high-pressure refrigerant is supplied to the expansion valve 1 from a condenser 102. More specifically, the high-pressure refrigerant from the condenser 102 is supplied to the first flow path 21.

[0055] When the valve disc 3 is seated on the valve seat 20, the first flow path 21 upstream of the valve chamber VS and the second flow path 22 downstream of the valve chamber VS are not in communication with each other. On the other hand, when the valve disc 3 is separated from the valve seat 20, the refrigerant supplied to the valve chamber VS is sent to the evaporator through the working rod insertion hole 27 and the second flow path 22. The expansion valve 1 is switched between the closed state (see FIG. 4) and the open state (FIG. 2) by the working rod 5 connected to the power element 8.

[0056] The power element 8 is provided with a pressure actuated chamber PA and a lower space LS separated by a diaphragm 83. Therefore, when the working gas in the pressure actuated chamber PA is liquefied, the working rod 5 moves toward the diaphragm by the biasing force of the biasing device 4, and when the liquefied working gas is vaporized, the driving force (valve opening force) of the power element 8 is transmitted via the stopper member 84, and the working rod 5 moves toward the valve body. In this way, the expansion valve 1 is switched between the open state and the closed state.

[0057] Furthermore, the lower space LS of the power element 8 is connected to the return flow path 23. Therefore, the phase (gas phase, liquid phase, etc.) of the working gas in the pressure actuated chamber PA changes depending on the temperature and pressure of the refrigerant flowing through the return flow path 23, and the actuating rod 5 is driven. In other words, in the expansion valve 1 shown in Fig. 1, the amount of refrigerant supplied from the expansion valve 1 to the evaporator is automatically adjusted depending on the temperature and pressure of the refrigerant returning from the evaporator to the expansion valve 1.

[0058] (Forced closing of expansion valve) Next, a forced valve closing operation of the expansion valve 1 using the solenoid valve EV will be described. In the solenoid valve EV, a position where the plunger 135 abuts against the valve seat member 112 is defined as a first position, and a position where the plunger 135 is separated from the valve seat member 112 is defined as a second position. A high-pressure refrigerant is supplied to the high-pressure chamber HS between the base 120 and the valve body 2 from the valve chamber VS via an inlet hole 2h.

[0059] 4, when electricity is supplied to the coil 132 from an external power supply device, the plunger 135 is urged to move in a direction away from the valve seat member 112 against the urging force of the compression coil spring 136. As a result, the end of the plunger 135 moves away from the second seal 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 seal member SL1, and the plunger 135 of the solenoid valve EV is in the second position.

[0060] In this second position, the pressure of the refrigerant in the high pressure chamber HS is transmitted from the circular through hole 112a of the valve seat member 112, through the radial hole 112c, the circumferential groove 112b, the communicating hole 2d, the pressure equalizing chamber EC, the connecting hole 62d, the gap between the operating rod 5 and the second hole 63b, and the through hole 63 to the cylinder chamber CS.

[0061] The side of the syringe member 6 opposite the cylinder chamber CS across the disk base 61 faces the return flow path (low pressure space) 23 through which a low pressure refrigerant passes. When the cylinder chamber CS becomes high pressure, the cylinder chamber CS tries to expand due to the pressure difference with the pressure of the refrigerant in the return flow path 23. On the other hand, the lower end of the shaft portion 62 of the syringe member 6 is maintained in abutment with the step portion 26a between the enlarged diameter hole 26 and the medium diameter hole 29, so that the cylinder chamber CS becomes high pressure, and the stopper member 84 is relatively pushed upward. As a result, the transmission of the driving force of the stopper member 84 that pushes the actuation rod 5 downward is interrupted, and the valve body 3 is urged upward by the urging force of the urging device 4 and seats on the valve seat 20, and the forced valve closed state is maintained regardless of the pressure difference between the pressure actuated chamber PA and the lower space LS.

[0062] When the pressure inside the cylinder chamber CS increases, an upward force is applied that presses the diaphragm 83 via the stopper member 84, but at the same time, a downward force is applied that presses the disk base 61 downward. This downward force is supported by the locking member 85, which cancels the upward force that urges the stopper member 84 upward, thereby preventing the diaphragm 83 from being deformed.

[0063] 2, when power is not supplied to the coil 132 from an external power supply device, the plunger 135 is urged to move in a direction approaching the valve seat member 112 by the urging force of the compression coil spring 136. As a result, the end of the plunger 135 abuts against the second seal member SL2, and the flange portion 113b of the valve shaft member 113 moves away from the first seal member SL1, so that the plunger 135 of the solenoid valve EV is in the first position.

[0064] At this time, the end of the plunger 135 abuts against the second seal member SL2, preventing the refrigerant in the high pressure chamber HS from passing through the circular through hole 112a and leaking into the intermediate passage 22a, without affecting the operation of the refrigeration cycle 100.

[0065] Immediately after the flange portion 113b of the valve shaft member 113 is separated from the first seal member SL1, the internal pressure of the cylinder chamber CS is higher than the pressure of the refrigerant in the intermediate passage 22a. Therefore, in the first position, the pressure in the intermediate passage 22a is transmitted to the cylinder chamber CS through the outlet hole 2j, the small opening 2g, the through hole 112a, the radial hole 112c, the circumferential groove 112b, the communication hole 2d, the pressure equalizing chamber EC, the connection hole 62d, the gap between the working rod 5 and the second hole 63b, and the through hole 63, and the pressure of the refrigerant in the cylinder chamber CS is rapidly reduced to be approximately equal to the pressure of the intermediate passage 22a (and the return flow path 23). As a result, the force pushing up the stopper member 84 disappears, and the pressing force from the diaphragm 83 can be transmitted to the upper end of the working rod 5, and the forced valve-closed state is released.

[0066] At this time, since the plunger 135 is in contact with the second seal SL2, the refrigerant is prevented from leaking from the high pressure chamber HS through the through hole 112a to the small opening 2g side, and the internal pressures of the pressure equalizing chamber EC and the cylinder chamber CS are maintained at low pressures, allowing the expansion valve 1 to perform its normal valve opening operation.

[0067] According to this embodiment, by supplying power to the solenoid valve EV, high-pressure refrigerant supplied from the condenser 102 can be introduced into the cylinder chamber CS to push up the stopper member 84, thereby achieving the forced valve-closing function of the expansion valve 1 regardless of the pressure in the pressure actuated chamber PA. At this time, the refrigerant from the condenser 102 is introduced directly into the valve chamber VS without passing through the solenoid valve EV, thereby suppressing pressure loss, etc.

[0068] Furthermore, by interrupting the power supply to the solenoid valve EV, the cylinder chamber CS is connected to the intermediate passage 22a, thereby quickly reducing the internal pressure of the cylinder chamber CS. This quickly eliminates the upward pushing force from the cylinder chamber CS to the stopper member 84, and resumes the transmission of the pushing force from the diaphragm 83 to the actuating rod 5 via the stopper member 84, thereby allowing the expansion valve 1 to perform its original opening operation.

[0069] Since the pressure of the high-pressure refrigerant supplied from the condenser 102 varies depending on conditions, using a high-pressure refrigerant to perform normal valve opening and closing operations may cause the normal valve opening and closing operations to become unstable. In contrast, according to this embodiment, by using a high-pressure refrigerant to perform the forced valve closing operation, there is an advantage in that the normal valve opening and closing operations can be stably performed.

[0070] Furthermore, the syringe member 6 is supported by the valve body 2 via a second O-ring OR2 made of natural or synthetic resin, and the actuation rod 5 is supported by a third O-ring OR3 made of natural or synthetic resin. Therefore, even if vibration occurs in the syringe member 6 or the actuation rod 5, the vibration can be suppressed by the damping function of the second O-ring OR2 and the third O-ring OR3.

[0071] Second embodiment Figure 5 is a schematic cross-sectional view showing the open state of the expansion valve 1A in the second embodiment, and Figure 6 is a longitudinal cross-sectional view showing the closed state of the expansion valve 1A in the second embodiment, each of which diagrammatically shows a refrigeration cycle 100A to which the expansion valve 1A is connected.

[0072] In this embodiment, instead of the solenoid valve of the first embodiment, a branch pipe is added to the refrigeration cycle 100A and an on-off valve is provided. Therefore, in addition to the branch pipe, the configuration of the valve body 2A is different from that of the above-mentioned embodiment, and the syringe member 6A has a hole 6e as a discharge part. Since the other configurations are the same as those of the first embodiment, the same reference numerals are used for the common configurations and the duplicated explanations are omitted.

[0073] In the refrigeration cycle 100A of this embodiment, a branch pipe (an inflow passage connected to an external flow passage upstream of the valve chamber and through which the refrigerant upstream of the valve chamber flows into a cylinder chamber) DP is arranged, branching from the pipe leading from the condenser 102 to the valve chamber VS of the expansion valve 1A and leading to a pipe base 105A of the expansion valve 1A, and an on-off valve (valve device) VL is attached to the branch pipe DP. The on-off valve VL can selectively operate between an open position that opens the branch pipe DP and a closed position that closes it. The on-off valve VL and the on-off valve VL constitute a supply section and a discharge section. The other configurations are the same as those of the refrigeration cycle of the first embodiment.

[0074] The communication hole 2d communicates between the pressure equalizing chamber EC of the valve body 2A and the outer periphery of the end of the large opening 2Ae. A pipe base 105A is attached to the large opening 2Ae. The pipe base 105A is fixed to the valve body 2A by screwing a male thread formed on the outer periphery of the pipe base 105A into a female thread formed on the inner periphery of the large opening 2Ae of the valve body 2A. A packing PK is disposed between the large opening 2Ae and the pipe base 105A to seal the gap between the pipe base 105A and the valve body 2A. As a result, a high pressure chamber HS is formed between the pipe base 105A and the large opening 2Ae.

[0075] The pipe base 105A has a pipe section 105Aa connected to the branch pipe DP via an on-off valve VL. The high pressure chamber HS communicates with the branch pipe DP via the internal flow path of the pipe base 105A and the pipe section 105Aa, and also communicates with the pressure equalizing chamber EC via the communication hole 2d, but does not communicate with the valve chamber VS. The rest of the configuration is the same as that of the expansion valve of the first embodiment.

[0076] The syringe member 6A has a hole 6e that releases the pressure of the cylinder chamber CS downstream of the valve chamber VS. The hole 6e is formed, for example, in the shaft portion 62 of the syringe member 6A. The hole 6e communicates between the through hole 63 and the return flow path 23. The hole 6e is set to a size that enables the valve body 3 to be driven by the actuating rod 5 by exhausting the pressure in the cylinder chamber CS during normal use of the expansion valve 1A except when the valve is forcibly closed, and that allows the valve to be forcibly closed smoothly by maintaining a sufficient pressure in the cylinder chamber CS when the valve is forcibly closed.

[0077] In this embodiment, one hole 6e is formed as an example, but the number of holes 6e is not limited to one and may be multiple. Also, the shape of the hole 6e is, for example, a hole having a circular planar shape, but the shape of the hole 6e is not limited. The hole 6e may be a slit, a long hole having a planar shape that is long in one direction, or the like.

[0078] Next, a forced valve closing operation of the expansion valve 1A using the on-off valve VL will be described. In the on-off valve VL, a position where the branch pipe DP is opened is defined as a second position, and a position where the branch pipe DP is blocked is defined as a first position.

[0079] When the on-off valve VL is in the second position (open position), the high-pressure refrigerant in the branch pipe DP is supplied to the high-pressure chamber HS via the pipe section 105Aa, and the pressure of the refrigerant in the high-pressure chamber HS is transmitted to the cylinder chamber CS via the communicating hole 2d, the pressure equalizing chamber EC, the connection hole 62d, and the through hole 63, making the internal pressure of the cylinder chamber CS high pressure.

[0080] When the cylinder chamber CS becomes high pressure, as described above, in a state where the lower end of the shaft portion 62 of the syringe member 6A abuts against the step portion 26a between the enlarged diameter hole 26 and the medium diameter hole 29 (the abutting position where the disk base portion 61 separates from the disk portion 84b of the stopper member 84 and abuts against the valve body 2A), the stopper member 84 is pushed relatively upward (FIG. 6). As a result, the transmission of the driving force of the stopper member 84 that pushes the actuating rod 5 downward is interrupted, and the valve body 3 is urged upward by the urging force of the urging device 4 and seats on the valve seat 20, and the forced valve closed state is maintained regardless of the pressure difference between the pressure actuated chamber PA and the lower space LS.

[0081] On the other hand, when the on-off valve VL is in the first position (closed position), the high pressure of the refrigerant in the branch pipe DP is no longer transmitted to the high pressure chamber HS, and some of the refrigerant in the cylinder chamber CS gradually flows out from the hole 6e formed in the shaft portion 62 into the return flow path 23. This reduces the internal pressure of the cylinder CS, so that the force pushing up the stopper member 84 disappears and the disk base 61 reaches the abutment position where it abuts against the disk portion 84b of the stopper member 84 (FIG. 5), making it possible to transmit the pressing force from the diaphragm 83 to the upper end of the operating rod 5, and the forced valve-closed state is released.

[0082] According to this embodiment, by operating the opening / closing valve VL to the second position, high-pressure refrigerant supplied from the compressor 101 is introduced into the cylinder chamber CS, thereby interrupting the transmission of driving force from the diaphragm 83 to the operating rod 5, thereby ensuring the forced closing operation of the expansion valve 1.

[0083] In response to this, the on-off valve VL is operated to the first position, thereby reducing the pressure in the cylinder chamber CS, and thereby restarting the transmission of driving force from the diaphragm 83 to the working rod 5, thereby realizing the original on-off valve operation of the expansion valve 1 in accordance with the operation of the power element 8. According to this embodiment, the refrigerant from the condenser 102 is introduced directly into the valve chest VS without passing through the on-off valve VL, thereby suppressing pressure loss and the like.

[0084] Instead of providing an on-off valve VL in the branch pipe DP, a three-way switching valve can be provided in the pipe from the condenser 102, and the three-way switching valve can selectively switch the high-pressure refrigerant from the condenser 102 to either a flow path toward the high-pressure chamber HS via the branch pipe DP or a flow path toward the valve chamber VS.

[0085] In such a case, the three-way valve sends high-pressure refrigerant to the high-pressure chamber HS via the branch pipe DP, thereby increasing the internal pressure of the cylinder chamber CS and achieving forced valve closure operation, and the three-way valve sends high-pressure refrigerant to the valve chamber VS, thereby achieving the operation of a normal expansion valve.

[0086] In this example, the flow path to the high pressure chamber HS and the flow path to the valve chamber VS are switched via a three-way switching valve. In another example, a three-way switching valve may be provided instead of the opening / closing valve VL arranged in the branch pipe DP to selectively switch between the flow path connecting the condenser 102 and the high pressure chamber HS and the flow path connecting the high pressure chamber HS and the inlet side of the evaporator 103. By connecting the high pressure chamber HS and the inlet side of the evaporator 103 via a three-way switching valve, the pressure of the cylinder chamber CS can be quickly reduced. According to this modification, it is not necessary to form a hole 6e in the syringe member 6A. The flow path connecting 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 path 22 or a flow path connecting the high pressure chamber HS and the intermediate passage 22a.

[0087] (First Modification) FIG. 7 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1B according to a first modified example, and shows a state in which the expansion valve 1B is installed in a refrigeration cycle 100A which is shown in schematic form. In the expansion valve 1B of this embodiment, only the shapes of the valve body 2B and the syringe member 6B differ from those of the second embodiment, and the other configurations are the same as those of the second embodiment, so the same symbols are used for the common configurations and duplicate explanations are omitted.

[0088] In the valve body 2B of the second embodiment, instead of a medium diameter hole that accommodates an O-ring, a pressure equalizing hole 29B that forms a pressure equalizing chamber EC is formed between the enlarged diameter hole 26 and the central hole 28 so as to be connected to the communication hole 2d. A clearance is formed between the central hole 28 and the actuating rod 5. Even when high pressure is supplied to forcibly close the valve, high-pressure fluid flows out through the clearance as described below, but this clearance is an amount that can maintain the pressure in the cylinder chamber CS at a pressure that can forcibly close the valve. Other than that, the configuration of the valve body 2B is the same as that of the second embodiment, so repeated explanations will be omitted.

[0089] Syringe member 6B has a different shape of shaft portion 62B, but disk base 61 is the same as in the second embodiment. Shaft portion 62B has only a through hole 63B with a uniform inner diameter, and does not have a circumferential groove on the outer periphery for accommodating an O-ring, or a hole communicating between the inside and the outside. The lower end of shaft portion 62B abuts against step portion 26a between enlarged diameter hole 26 and pressure equalizing hole 29B. The rest of the configuration of syringe member 6B is the same as in the above-mentioned embodiment.

[0090] In this modification, when the on-off valve VL is in the second position (open position), the high-pressure refrigerant in the branch pipe DP is supplied to the high-pressure chamber HS via the pipe section 105Aa, and the pressure of the refrigerant in the high-pressure chamber HS is transmitted to the cylinder chamber CS via the communication hole 2d, the pressure equalizing chamber EC, and the through hole 63B, making the internal pressure of the cylinder chamber CS high. As a result, the transmission of the driving force of the stopper member 84 that presses the actuating rod 5 downward is interrupted, so that the valve body 3 is urged upward by the urging force of the urging device 4 and seats on the valve seat 20, and the forced valve-closed state is maintained regardless of the pressure difference between the pressure actuating chamber PA and the lower space LS.

[0091] On the other hand, when the on-off valve VL is in the first position (closed position), the high pressure of the refrigerant in the branch pipe DP is not transmitted to the high pressure chamber HS, and some of the refrigerant in the cylinder chamber CS flows into the intermediate passage 22a through the through hole 63B, the gap between the central hole 28, and the actuating rod 5. This reduces the internal pressure of the cylinder CS, so that the force pushing up the stopper member 84 disappears and the pressing force from the diaphragm 83 can be transmitted to the upper end of the actuating rod 5, and the forced valve closed state is released.

[0092] According to this modified example, since the O-ring can be omitted, assembly is improved and costs can be reduced.

[0093] (Second Modification) FIG. 8 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1C according to a second modified example, and shows a state in which the expansion valve 1C is installed in a refrigeration cycle 100A shown in schematic form. In the expansion valve 1C of this modified example, only the shapes of the valve body 2C and the syringe member 6C differ from those of the second embodiment; the other configurations are the same as those of the second embodiment, so the same symbols are used for the common configurations and duplicate explanations are omitted.

[0094] In the valve body 2C, the inner diameter of the communication passage 2Cb is smaller than the inner diameter of the opening 2Ca (a hole in which the syringe member 6C is movably disposed) compared to the second embodiment, and therefore a step portion 2Cm (a bottom surface of the internal space of the opening 2Ca) is formed between the opening 2Ca and the communication passage 2Cb. Other than that, the configuration of the valve body 2C is the same as that of the second embodiment, so a duplicated description will be omitted.

[0095] The syringe member 6C is formed by coaxially connecting a disk base portion (also simply referred to as a base portion) 61C at the upper end side and a shaft portion (also referred to as a syringe member shaft portion) 62C at the lower end side, and has a through hole 63C penetrating from the upper end side to the lower end. The through hole 63C has a first hole 63Ca at the upper end side and a second hole 63Cb at the lower end side. The disk base portion 61C has a shape in which the diameter is smaller at the lower end than at the upper end, and this small diameter portion is called an intermediate portion 64C. The intermediate portion 64c and the step portion 2Cm at the other end of the shaft portion 62C, or the disk base portion 61C and the surface of the valve body 2C facing the disk base portion 61C constitute a movement restricting portion. The second hole 63Cb has an inner diameter smaller than that of the first hole 63Ca, and is slidably fitted to the outer periphery 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 that allows high-pressure fluid to flow from the pressure equalizing chamber EC to the cylinder chamber CS via the clearance.

[0096] The disk base 61C is housed in a cylindrical recess 84a of a hollow stopper member 84 of the power element 8. A first circumferential groove 61Ca is formed on the outer periphery of the disk base 61C, and a first O-ring OR1 is disposed therein to provide a seal between the cylindrical recess 84a and the disk base 61C.

[0097] The intermediate portion 64C adjacent to the disk base portion 61C passes through the annular locking member 85, and its lower end is capable of abutting against the step portion 2Cm of the opening 2Ca.

[0098] A second circumferential groove 62Ca is formed on the outer periphery of the shaft portion 62C near the lower end thereof, and a second O-ring OR2 is disposed inside the second circumferential groove 62Ca to provide a seal between the enlarged diameter hole 26 of the valve body 2C and the shaft portion 62C. The shaft portion 62C is slidably fitted into the enlarged diameter hole 26.

[0099] A small diameter portion 62Cb is formed at the lower end of the shaft portion 62C below the second circumferential groove 62Ca, and faces the third O-ring OR3 housed in the medium diameter hole 29. The space between the small diameter portion 62Cb and the enlarged diameter hole 26 forms a pressure equalizing chamber EC. It is preferable that the lower end of the small diameter portion 62Cb does not contact the third O-ring OR3 when the lower end of the intermediate portion 64C of the syringe member 6C abuts against the step portion 2Cm of the opening 2Ca. In addition, a hole 6e is formed to communicate the inside and outside of the shaft portion 62C.

[0100] In this modification, when the on-off valve VL is in the second position (open position), as shown in Fig. 8, the high-pressure refrigerant in the branch pipe DP is supplied to the high-pressure chamber HS through the pipe portion 105Aa, and the pressure of the refrigerant in the high-pressure chamber HS is transmitted to the cylinder chamber CS through the communication hole 2d, the pressure equalizing chamber EC, the gap between the second hole 63Cb and the actuating rod 5, and the through hole 63C. When the lower end of the middle portion 64C of the syringe member 6C is in contact with the step portion 2Cm of the opening 2Ca, the internal pressure of the cylinder chamber CS is made high, and the transmission of the driving force of the stopper member 84 that pushes the actuating rod 5 downward is interrupted, so that the valve body 3 is urged upward by the urging force of the urging device 4 and seats on the valve seat 20, and the forced valve closed state is maintained regardless of the pressure difference between the pressure actuating chamber PA and the lower space LS.

[0101] On the other hand, when the on-off valve VL is in the first position (closed position), the high pressure of the refrigerant in the branch pipe DP is no longer transmitted to the high pressure chamber HS, and some of the refrigerant in the cylinder chamber CS gradually flows out from the hole 6e formed in the shaft portion 62C into the return flow path 23. This reduces the internal pressure of the cylinder CS, so the force pushing up the stopper member 84 disappears and the pressing force from the diaphragm 83 can be transmitted to the upper end of the working rod 5, and the forced valve closed state is released.

[0102] Here, in the second embodiment, in order to realize a forced valve closing operation, the axial dimension of the syringe member 6 is set so that the disk base 61 is spaced from the lower surface of the disk portion 84b of the stopper member 84 with the lower end of the shaft portion 62 abutting against the step portion 26a between the enlarged diameter hole 26 and the medium diameter hole 29. For this reason, it becomes necessary to manage the overall length of the syringe member 6, which is relatively long, and the dimension from the upper end of the valve body 2C to the step portion 26a between the enlarged diameter hole 26 and the medium diameter hole 29, which is time-consuming.

[0103] In contrast, according to this modified example, in order to achieve forced valve closing operation, it is sufficient to control the dimensions of the intermediate portion 64C, which is relatively close to the upper end of the syringe member 6C, and from the valve body 2C to the step portion 2Cm of the opening 2Ca, thereby improving ease of manufacture.

[0104] (Third Modification) FIG. 9 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1D according to a third modified example, and shows a state in which the expansion valve 1D is installed in a refrigeration cycle 100A which is shown in schematic form. In the expansion valve 1D of this modified example, the shapes of the power element 8D and the syringe member 6D are different from those of the second modified example, and the other configurations, including the valve body 2A, are the same as those of the second embodiment, so that the same symbols are used for the common configurations and redundant explanations are omitted.

[0105] The power element 8D differs from the second embodiment only in the shapes of the stopper member 84D and the receiving member 86D, and the plug 81, the top cover member 82, and the diaphragm 83 are the same as those of the second embodiment, so the same symbols are used for the common configurations and duplicate explanations are omitted.

[0106] The receiving member 86D has an annular first flange portion 86Da whose outer periphery is welded to the upper cover member 82, a first cylindrical portion 86Db connected to the inner edge of the first flange portion 86Da and extending downward, an annular second flange portion 86Dc connected to the lower end of the first cylindrical portion 86Db and facing radially inward, and a second cylindrical portion 86Dd connected to the inner edge of the second flange portion 86Dc and extending downward. A male thread 86De that screws into a female thread formed on the inner periphery of the opening 2a is formed on the outer periphery of the second cylindrical portion 86Dd.

[0107] The syringe member 6D is formed by coaxially connecting a disk base portion (also simply referred to as a base portion) 61D at the upper end side and a shaft portion (also referred to as a syringe member shaft portion) 62D at the lower end side, and has a through hole 63D penetrating from the upper end side to the lower end. In the present embodiment, as an example, the disk base portion 61D is formed in a shape in which the lower portion has a smaller diameter than the upper portion. The portion formed with the smaller diameter is referred to as an intermediate portion 64D. In this modification, the disk base portion 61D and the second flange portion 86Dc abutting against the intermediate portion 64D constituting a part of the disk base portion 61D constitute a movement restricting portion that restricts the movement of the syringe member 6D toward the valve chamber VS. The through hole 63D has a first hole 63Da at the upper end side and a second hole 63Db at the lower end side. The second hole 63Db has an inner diameter smaller than that of the first hole 63Da, and is slidably fitted to the outer periphery 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 that allows the high-pressure fluid to flow from the pressure equalizing chamber EC to the cylinder chamber CS via the clearance.

[0108] The disk base 61D is housed in a cylindrical recess 84Da of a stopper member 84D of the power element 8D. A first circumferential groove 61Da is formed on the outer periphery of the disk base 61D, and a first O-ring OR1 is disposed therein to provide a seal between the cylindrical recess 84Da and the disk base 61D.

[0109] The intermediate portion 64D adjacent to the disk base portion 61D passes through an annular locking member 85, and its lower end is capable of abutting against the upper surface of a second flange portion 86Dc of a receiving member 86D of the power element 8D.

[0110] A second circumferential groove 62Da is formed on the outer periphery of the shaft portion 62D near the lower end thereof, and a second O-ring OR2 is disposed inside the second circumferential groove 62Da to provide a seal between the enlarged diameter hole 26 of the valve body 2A and the shaft portion 62D. The shaft portion 62D is slidably fitted into the enlarged diameter hole 26.

[0111] A small diameter portion 62Db is formed at the lower end of the shaft portion 62D below the second circumferential groove 62Da, and faces the third O-ring OR3 housed in the medium diameter hole 29. The area between the small diameter portion 62Db and the enlarged diameter hole 26 forms a pressure equalizing chamber EC. It is preferable that, when the lower end of the intermediate portion 64D of the syringe member 6D abuts against the upper surface of the second flange portion 86Dc of the receiving member 86D, the lower end of the small diameter portion 62Cb does not abut against the third O-ring OR3, and the valve chamber side end face of the disk base 61D is located closer to the valve chamber side than the valve chamber side end face of the stopper member 84D. Also, a hole 6e is formed to communicate between the inside and outside of the shaft portion 62D.

[0112] The stopper member 84D has a disk portion 84Db and a circular tube portion 84Dc that is connected to the outer periphery of the disk portion 84Db and extends downward. The inside of the circular tube portion 84c is a cylindrical recess 84a. An annular locking member 85 is attached to the inner peripheral step at the lower end of the circular tube portion 84Dc. After the disk base portion 61D of the syringe member 6D is inserted into the cylindrical recess 84Da, the locking member 85 is attached to the circular tube portion 84Dc by crimping the crimping portion 84Dd at the lower end of the circular tube portion 84Dc disposed on the outer periphery of the locking member 85 radially inward, thereby preventing the disk base portion 61D from coming off the stopper member 84D. The disk base portion 61D has a dimension that faces (butts against) the second flange portion 86Dc in the moving direction of the shaft portion 62D.

[0113] In this modification, when the on-off valve VL is in the second position (open position), as shown in Fig. 9, the high-pressure refrigerant in the branch pipe DP is supplied to the high-pressure chamber HS through the pipe portion 105Aa, and the pressure of the refrigerant in the high-pressure chamber HS is transmitted to the cylinder chamber CS through the communication hole 2d, the pressure equalizing chamber EC, the gap between the second hole 63Db and the actuating rod 5, and the through hole 63D. When the lower end of the middle portion 64D of the syringe member 6D is in abutment with the upper surface of the second flange portion 86Dc of the receiving member 86D (butting position), the internal pressure of the cylinder chamber CS is made high pressure, and the transmission of the driving force of the stopper member 84D that pushes the actuating rod 5 downward is interrupted, so that the valve body 3 is urged upward by the urging force of the urging device 4 and seats on the valve seat 20, and the forced valve closed state is maintained regardless of the pressure difference between the pressure actuating chamber PA and the lower space LS.

[0114] On the other hand, when the on-off valve VL is in the first position (closed position), the high pressure of the refrigerant in the branch pipe DP is no longer transmitted to the high pressure chamber HS, and some of the refrigerant in the cylinder chamber CS gradually flows out from the hole 6e formed in the shaft portion 62D into the return flow path 23. This reduces the internal pressure of the cylinder CS, eliminating the force pushing up the stopper member 84D and enabling the pressing force from the diaphragm 83 to be transmitted to the upper end of the working rod 5, releasing the forced valve-closed state.

[0115] According to this modification, the middle portion 64D of the syringe member 6D can be abutted against the receiving member 86, which can be formed inexpensively by press molding, thereby reducing the amount of machining on the valve body side and achieving cost reduction.

[0116] (Fourth Modification) FIG. 10 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1E according to a fourth modified example, and shows a state in which the expansion valve 1E is installed in a refrigeration cycle 100A which is shown in schematic form. In the expansion valve 1E of this modification, the shapes of the valve body 2E, the power element 8E, and the syringe member 6E are different from those of the second embodiment, and other configurations are the same as those of the second embodiment, so that the same reference numerals are used for the common configurations and redundant explanations are omitted. In the other embodiments and modifications, the syringe member is disposed inside the stopper member, but in this modification, the stopper member 84E is disposed inside the syringe member 6E.

[0117] In the valve body 2E of the second embodiment, the inner diameter of the communication passage 2Eb is smaller than the inner diameter of the opening 2Ea, and therefore a step portion 2Em is formed between the opening 2Ea and the communication passage 2Eb. Other than that, the configuration of the valve body 2E is the same as that of the second embodiment, so a duplicated description will be omitted.

[0118] The power element 8E differs from the second embodiment only in the shape of the stopper member 84E. The plug 81, the top cover member 82, the diaphragm 83, and the receiving member 86 are the same as those in the second embodiment, so the same symbols are used for the common configurations and duplicate explanations are omitted.

[0119] The cylindrical stopper member 84E has an expanded diameter cylindrical portion 84Ea and a small diameter cylindrical portion 84Eb having a smaller diameter than the expanded diameter cylindrical portion 84Ea. A circumferential groove 84Ed is formed on the outer periphery of the expanded diameter cylindrical portion 84Ea, and a first O-ring OR1 is disposed inside the circumferential groove 84Ed.

[0120] The syringe member 6E is formed by coaxially connecting a circular pipe base (also simply referred to as a base) 61E at the upper end side and a shaft portion (also referred to as a syringe member shaft portion) 62E at the lower end side via an annular intermediate portion 64E. In this modification, the peripheral surface of the opening 2Eb that abuts against the intermediate portion 64E that constitutes a part of the circular pipe base 61E constitutes a movement restricting portion that restricts the movement of the syringe member 6E toward the valve chamber VS. The shaft portion 62E has a through hole 63E that penetrates from the upper end side to the lower end. The through hole 63E has a first hole 63Ea at the upper end side and a second hole 63Eb at the lower end side. The second hole 63Eb has an inner diameter smaller than that of the first hole 63Ea and is slidably fitted to the outer periphery 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 that allows high-pressure fluid to flow from the pressure equalizing chamber EC to the cylinder chamber CS through it.

[0121] An enlarged diameter columnar portion 84Ea of a stopper member 84E is slidably fitted onto the inner periphery of the circular pipe base 61E, and a first O-ring OR1 provides a seal between the stopper member 84E and the circular pipe base 61E.

[0122] An annular locking member 85 is attached to the inner circumferential step at the upper end of the circular pipe base 61E. After inserting the enlarged diameter columnar portion 84Ea of the stopper member 84E into the circular pipe base 61E, the crimped portion 61Ea at the upper end of the circular pipe base 61E disposed on the outer periphery of the locking member 85 is crimped radially inward, thereby attaching the locking member 85 to the syringe member 6E, thereby preventing the stopper member 84E from coming off from the syringe member 6E.

[0123] A second circumferential groove 62Ea is formed on the outer periphery of the shaft portion 62E near the lower end thereof, and a second O-ring OR2 is disposed inside the second circumferential groove 62Ea to provide a seal between the enlarged diameter hole 26 of the valve body 2E and the shaft portion 62E. The shaft portion 62E is slidably fitted into the enlarged diameter hole 26.

[0124] A small diameter portion 62Eb is formed at the lower end of the shaft portion 62E below the second circumferential groove 62Ea, and faces the third O-ring OR3 housed in the medium diameter hole 29. The space between the small diameter portion 62Eb and the enlarged diameter hole 26 forms a pressure equalizing chamber EC. It is preferable that the lower end of the small diameter portion 62Eb does not contact the third O-ring OR3 when the lower surface of the middle portion 64E of the syringe member 6E abuts against the step between the opening 2a and the communication passage 2b. In addition, a hole 6e is formed to communicate between the inside and outside of the shaft portion 62E.

[0125] In this modification, when the on-off valve VL is in the second position (open position), as shown in Fig. 10, the high-pressure refrigerant in the branch pipe DP is supplied to the high-pressure chamber HS through the pipe portion 105Aa, and the pressure of the refrigerant in the high-pressure chamber HS is transmitted to the cylinder chamber CS through the communication hole 2d, the pressure equalizing chamber EC, the gap between the second hole 63Eb and the actuating rod 5, and the through hole 63E. When the lower surface of the middle portion 64E of the syringe member 6E is in contact with the step portion 2Em between the opening 2Ea and the communication passage 2Eb, the internal pressure of the cylinder chamber CS is made high, and the transmission of the driving force of the stopper member 84E that presses the actuating rod 5 downward is interrupted, so that the valve body 3 is urged upward by the urging force of the urging device 4 and seats on the valve seat 20, and the forced valve closed state is maintained regardless of the pressure difference between the pressure actuating chamber PA and the lower space LS.

[0126] On the other hand, when the on-off valve VL is in the first position (closed position), the high pressure of the refrigerant in the branch pipe DP is no longer transmitted to the high pressure chamber HS, and some of the refrigerant in the cylinder chamber CS gradually flows out from the hole 6e formed in the shaft portion 62E into the return flow path 23. This reduces the internal pressure of the cylinder CS, so the force pushing up the stopper member 84E disappears, and the pressing force from the diaphragm 83 can be transmitted to the upper end of the working rod 5, and the forced valve closed state is released.

[0127] (Fifth Modification) FIG. 11 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1F according to a fifth modified example, and shows a state in which the expansion valve 1F is installed in a refrigeration cycle 100A which is shown in schematic form. In the expansion valve 1F of this modified example, the shapes of the valve body 2F and the syringe member 6F are different from those of the second embodiment, but the other configurations are similar to those of the second embodiment, so the same symbols are used for the common configurations and duplicate explanations are omitted.

[0128] This modification is a modification of the second embodiment in that it uses a dedicated flow passage and an on-off valve for exhausting the pressure in the cylinder chamber CS.

[0129] In the valve body 2F, a discharge passage EX that communicates the pressure equalizing chamber EC with the outside is formed, and the outer end of this discharge passage EX is connected to the inlet side of the evaporator 103 via a second on-off valve (second valve device) VL2 and a pipe (also called an external flow path portion) HT. In this modification, the discharge passage EX is included in the outflow path. The other configurations are the same as those of the embodiment shown in FIG. 5 except that the syringe member 6F does not have a hole 6e, so that repeated explanations will be omitted.

[0130] In the expansion valve 1F, by opening the on-off valve VL while closing the second on-off valve VL2, high-pressure refrigerant is introduced into the pressure equalizing chamber EC, thereby realizing a forced valve closing operation. On the other hand, by opening the second on-off valve VL2 while closing the on-off valve VL, refrigerant flows from the pressure equalizing chamber EC through the exhaust passage EX and the pipe HT to the evaporator 103, thereby realizing a normal operation of the expansion valve 1F.

[0131] According to this modification, the refrigerant can be quickly caused to flow out from the pressure equalizing chamber EC through the discharge passage EX and the pipe HT, and the expansion valve 1F can be smoothly shifted from the forced valve closing operation to the normal operation.

[0132] (Sixth Modification) FIG. 12 is a vertical cross-sectional view similar to FIG. 6 of an expansion valve 1G in a refrigeration cycle 100G according to a sixth modified example. The expansion valve 1G of this modified example differs from the second embodiment in that it is provided with a second pipe HT2 connecting the piping section 105Aa to the inlet side of the evaporator 103, and a second opening / closing valve VL2 for opening and closing the second pipe HT2.Other than that, the configuration is the same as in the second embodiment, so the same symbols are used for the common configurations and redundant explanations are omitted.

[0133] In this modification, by opening the on-off valve VL while closing the second on-off valve VL2, high-pressure refrigerant is introduced into the pressure-equalizing chamber EC via the high-pressure chamber HS, thereby achieving a forced valve closing operation. On the other hand, by opening the second on-off valve VL2 while closing the on-off valve VL, refrigerant flows from the pressure-equalizing chamber EC through the high-pressure chamber HS and the second pipe HT2 to the evaporator 103.

[0134] In the first embodiment, the second embodiment, and each modified example, an example has been described in which the locking member 85 that restricts the movement of the syringe members 6, 6A, 6B, 6C, 6D, 6E, 6F relative to the stopper members 84, 84D, 84E is provided on the stopper members 84, 84D, 84E. In another example, the locking member 85 may be provided on the syringe members 6, 6A, 6B, 6C, 6D, 6E, 6F. As an example of a configuration in which the locking member 85 is provided on the syringe members 6, 6A, 6B, 6C, 6D, 6E, 6F, the locking member 85 may be provided on the outer periphery of the syringe members 6, 6A, 6B, 6C, 6D, 6E, 6F, and the stopper members 84, 84D, 84E may be provided with a protrusion that abuts against the locking member 85. When this protrusion comes into contact with the locking member 85, the syringe members 6, 6A, 6B, 6C, 6D, 6E, and 6F are prevented from moving further relative to the stopper members 84, 84D, and 84E.

[0135] The locking member 85 is not limited to being provided separately from the syringe members 6, 6A, 6B, 6C, 6D, 6E, and 6F and fixed to the syringe members. In another example, the locking member 85 may be formed integrally with the syringe members 6, 6A, 6B, 6C, 6D, 6E, and 6F. The term "integral" here means that the stopper member and the locking member are formed as one member. That is, a part of the syringe members 6, 6A, 6B, 6C, 6D, 6E, and 6F may constitute the locking member 85. The same applies to a configuration in which the locking member 85 is provided on the stopper members 84, 84D, and 84E, and the locking member 85 may be formed integrally with the stopper members 84, 84D, and 84E.

[0136] This specification includes the disclosure of the following inventions. (First aspect) a valve body having a valve chamber and a valve seat; a power element provided in the valve body and having a displaceable displacement portion; a valve body disposed in the valve chamber; a first biasing device that biases the valve body toward the valve seat; an actuating rod that is provided in the valve body, disposed between the displacement portion and the valve body, and drives the valve body in response to displacement of the displacement portion; a syringe member provided in the valve body, movably housing a portion of the actuation rod therein, and defining a cylinder chamber between the syringe member and the displacement portion that is expandable and contractable in the movement direction of the valve body; a movement restriction portion that restricts movement of the syringe member toward the valve chamber; a supply unit that supplies the fluid in the valve chamber or the fluid upstream of the valve chamber to the cylinder chamber. An expansion valve characterized by:

[0137] (Second aspect) 10. The expansion valve according to claim 1, further comprising a discharge portion that discharges pressure in the cylinder chamber downstream of the valve chamber.

[0138] (Third aspect) The supply unit includes: an inflow passage formed in the valve body for allowing the fluid in the valve chamber or a fluid upstream of the valve chamber to flow into the cylinder chamber; a first valve device provided in the inlet passage and configured to control the inflow of the fluid into the cylinder chamber; Equipped with the discharge portion includes an outlet passage through which the fluid in the cylinder chamber flows downstream of the valve chamber, the outflow passage includes a part of the inflow passage and a branch passage branching from the part to communicate the part with a downstream side of the valve chamber, The first valve device also serves as a second valve device and is configured to be switchable 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. An expansion valve according to a second aspect,

[0139] (Fourth aspect) The inlet passage is a first hole formed in the valve body and into which a portion of the syringe member on the valve chamber side is disposed; a second hole formed in the syringe member and communicating with the first hole and the cylinder chamber; a first flow passage portion formed in the valve body and communicating with the valve chamber or with an upstream side of the valve chamber; a second flow passage portion formed in the valve body and communicating with the first hole; a connection chamber formed in the valve body and connected to the first flow path portion and the second flow path portion; Equipped with The outflow path is the second flow path portion, the connection chamber, and a third flow path portion that communicates a downstream side of the valve chamber with the connection chamber, The connecting chamber is a first communication flow path that communicates the first flow path portion and the second flow path portion; a second communication flow path that communicates the second flow path portion and the third flow path portion; Equipped with the first valve device includes a valve shaft member disposed in the connection chamber, and a drive device that drives the valve shaft member, the valve shaft member is formed to be movable between a second position in which the first flow path portion and the second flow path portion are communicated with each other via the first communication flow path of the connection chamber, and both the first flow path portion and the second flow path portion are not communicated with the third flow path portion, and a first position in which the second flow path portion and the third flow path portion are communicated with each other via the second communication flow path of the connection chamber, and both the second flow path portion and the third flow path portion are not communicated with the first flow path portion. An expansion valve according to a third aspect,

[0140] (Fifth aspect) The drive device is a drive unit provided in the valve body, the drive unit having a plunger and configured to move the valve shaft member from one of the first position and the second position to the other by the plunger; a second biasing device provided in the connection chamber and biasing the valve shaft member from the other side toward the one side; An expansion valve according to a fourth aspect, comprising:

[0141] (Sixth aspect) a valve seat member disposed in the connecting chamber between an opening of the first flow path portion and an opening of the third flow path portion to prevent a fluid from flowing from the first flow path portion to the third flow path portion, covering the opening of the second flow path portion, and having a gap between the opening of the third flow path portion and a valve seat member; the valve seat member has a through hole penetrating in a moving direction of the plunger, and a relay path relaying the through hole and the opening of the second flow path portion, The valve shaft member includes a shaft portion that is disposed within the through hole, is formed to be movable in the axial direction of the through hole, and forms a flow path between the shaft portion and an inner surface of the through hole, and a flange portion that is provided on the shaft portion, is disposed in the gap, and abuts against the valve seat member to disconnect an opening of the through hole from the connection chamber. Equipped with a tip end surface of the plunger is formed into a surface that, when it comes into contact with the valve shaft member, causes an opening of the through hole and the connection chamber to be disconnected from each other; An expansion valve according to a fifth aspect,

[0142] (Seventh aspect) a periphery of the opening of the through hole on an end surface of the valve seat member facing the third flow path portion is formed by a first seal member, a periphery of the opening of the through hole on the end surface of the valve seat member on the drive portion side is formed by a second seal member; An expansion valve according to a sixth aspect,

[0143] (Eighth aspect) The supply unit includes: an inflow passage provided in the valve body and connected to an external flow passage portion upstream of the valve chamber outside the valve body, for allowing the fluid upstream of the valve chamber to flow into the cylinder chamber; a valve device provided in the inflow passage or the external flow passage portion and configured to control the inflow of the fluid into the cylinder chamber via the inflow passage; The expansion valve according to any one of the first to seventh aspects, comprising:

[0144] (Ninth aspect) The discharge section is an outflow passage provided in the valve body and connected to an external flow passage portion downstream of the valve chamber outside the valve body, for allowing the fluid in the cylinder chamber to flow downstream of the valve chamber via the external flow passage portion; a valve device provided in the outflow passage or the external flow passage portion, the valve device controlling the outflow of the fluid in the cylinder chamber to a downstream side of the valve chamber via the outflow passage; The expansion valve according to any one of the second to eighth aspects, comprising:

[0145] (Tenth Aspect) the valve body has a low-pressure flow passage through which a fluid having a pressure lower than that in the valve chamber flows, The power element is a housing fixed to the valve body; a diaphragm provided in the housing and dividing the inside of the housing into a pressure actuated chamber and a valve chamber side chamber communicating with the low pressure flow path; a stopper member disposed in the valve-chamber side chamber and serving as the displacement portion; a locking portion provided on one of the stopper member and the syringe member; Equipped with The syringe member is disposed inside the stopper member, or the stopper member is disposed inside the syringe member, An expansion valve of a first aspect, characterized in that the engaging portion abuts against the other of the stopper member and the syringe member, thereby preventing the syringe member from slipping out of the stopper member or the stopper member from slipping out of the syringe member.

[0146] (Eleventh aspect) The lower end of the housing has an inwardly extending flange portion, The syringe member has a shaft portion that is inserted into the inside of the flange portion, and a base portion that is attached to an end portion of the shaft portion on the power element side and has a dimension larger than that of the shaft portion, the base portion has a dimension to face the flange portion in a moving direction of the shaft portion, when the movement of the syringe member relative to the stopper member is restricted by the engaging portion, the end surface of the base portion on the valve chamber side is located closer to the valve chamber than the end surface of the stopper member on the valve chamber side, The flange portion and the base portion constitute the movement restricting portion. The expansion valve according to any one of the first to tenth aspects, characterized in that

[0147] (Twelfth aspect) The syringe member has a shaft portion and a base portion provided at one end of the shaft portion on the power element side and having a dimension larger than the shaft portion in a direction perpendicular to an axis of the shaft portion, the valve body has a hole in which the syringe member is movably disposed, The other end of the shaft portion and a bottom surface of the internal space of the hole, or the base portion and a surface of the valve body facing the base portion constitute the movement restriction portion. The expansion valve according to any one of the first to tenth aspects, characterized in that

[0148] (Thirteenth aspect) The syringe member has a tubular base and a shaft connected to the base, The displacement portion is slidably fitted to an inner periphery of the base portion, The shaft portion is inserted through an opening of the valve body having a dimension smaller than that of the base portion, The movement restriction portion is configured by the periphery of the opening. The expansion valve according to any one of the first to twelfth aspects, characterized in that [Explanation of symbols]

[0149] 1, 1A, 1B, 1C, 1D, 1E, 1F, 1G: Expansion valve 2, 2A, 2B, 2C, 2E, 2F: Valve body 3: Valve body 4: Actuating device 5: Operating rod 6, 6A, 6B, 6C, 6D, 6E, 6F: Syringe parts 8, 8E: Power Element 20: Valve seat 140: Attractor 135: Plunger 132: Coil EV: Solenoid valve VS: Valve chamber VL: Open / close valve VL2: Second on-off valve CS: Cylinder chamber HS: Hyperbaric chamber

Claims

1. a valve body having a valve chamber and a valve seat; a power element provided in the valve body and having a displaceable displacement portion; a valve body disposed in the valve chamber; a first biasing device that biases the valve body toward the valve seat; an actuating rod that is provided in the valve body, disposed between the displacement portion and the valve body, and drives the valve body in response to displacement of the displacement portion; a syringe member provided in the valve body, movably housing a portion of the actuation rod therein, and defining a cylinder chamber between the syringe member and the displacement portion that is expandable and contractable in the movement direction of the valve body; a movement restriction portion that restricts movement of the syringe member toward the valve chamber; a supply section that supplies a fluid in the valve chamber or a fluid upstream of the valve chamber to the cylinder chamber; Equipped with An expansion valve characterized by:

2. 2. The expansion valve according to claim 1, further comprising a discharge portion that discharges pressure in the cylinder chamber downstream of the valve chamber.

3. The supply unit includes: an inflow passage formed in the valve body for allowing the fluid in the valve chamber or a fluid upstream of the valve chamber to flow into the cylinder chamber; a first valve device provided in the inlet passage and configured to control the inflow of the fluid into the cylinder chamber; Equipped with the discharge portion includes an outflow passage through which the fluid in the cylinder chamber flows downstream of the valve chamber, the outflow passage includes a part of the inflow passage and a branch passage branching from the part to communicate the part with a downstream side of the valve chamber, The first valve device also serves as a second valve device and is configured to be switchable 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.

3. The expansion valve according to claim 2.

4. The inlet passage is a first hole formed in the valve body and into which a portion of the syringe member on the valve chamber side is disposed; a second hole formed in the syringe member and communicating with the first hole and the cylinder chamber; a first flow passage portion formed in the valve body and communicating with the valve chamber or with a portion upstream of the valve chamber; a second flow passage portion formed in the valve body and communicating with the first hole; a connecting chamber formed in the valve body and connected to the first flow path portion and the second flow path portion; Equipped with The outflow path is the second flow path portion, the connection chamber, and a third flow path portion that communicates a downstream side of the valve chamber with the connection chamber, The connecting chamber is a first communication flow path that communicates the first flow path portion and the second flow path portion; a second communication flow path that communicates the second flow path portion and the third flow path portion; Equipped with the first valve device includes a valve shaft member disposed in the connection chamber, and a drive device that drives the valve shaft member, the valve shaft member is formed to be movable between a second position in which the first flow path portion and the second flow path portion are communicated with each other via the first communication flow path of the connection chamber, and both the first flow path portion and the second flow path portion are not communicated with the third flow path portion, and a first position in which the second flow path portion and the third flow path portion are communicated with each other via the second communication flow path of the connection chamber, and both the second flow path portion and the third flow path portion are not communicated with the first flow path portion.

4. The expansion valve according to claim 3.

5. The drive device is a drive unit provided on the valve body, the drive unit having a plunger and configured to move the valve shaft member from one of the first position and the second position to the other by the plunger; a second biasing device provided in the connection chamber and biasing the valve shaft member from the other side toward the one side; The expansion valve according to claim 4, further comprising:

6. a valve seat member disposed in the connecting chamber between an opening of the first flow path portion and an opening of the third flow path portion to prevent a fluid from flowing from the first flow path portion to the third flow path portion, covering the opening of the second flow path portion, and having a gap between the opening of the third flow path portion and the valve seat member; the valve seat member has a through hole penetrating in a moving direction of the plunger, and a relay passage relaying the through hole and the opening of the second flow path portion, The valve shaft member includes a shaft portion that is disposed within the through hole, is formed to be movable in the axial direction of the through hole, and forms a flow path between the shaft portion and an inner surface of the through hole, and a flange portion that is provided on the shaft portion, is disposed in the gap, and abuts against the valve seat member to disconnect an opening of the through hole from the connection chamber. Equipped with a tip end surface of the plunger is formed into a surface that, when it comes into contact with the valve shaft member, causes an opening of the through hole and the connection chamber to be disconnected from each other; 6. The expansion valve according to claim 5.

7. a periphery of the opening of the through hole on an end surface of the valve seat member facing the third flow path portion is formed by a first seal member, a periphery of the opening of the through hole on the end surface of the valve seat member facing the drive portion is formed by a second seal member; 7. The expansion valve according to claim 6.

8. The supply unit includes: an inflow passage provided in the valve body and connected to an external flow passage portion upstream of the valve chamber outside the valve body, for allowing the fluid upstream of the valve chamber to flow into the cylinder chamber; a valve device provided in the inflow passage or the external flow passage portion and configured to control the inflow of the fluid into the cylinder chamber via the inflow passage; The expansion valve according to claim 1 ,

9. The discharge section is an outflow passage provided in the valve body and connected to an external flow passage portion downstream of the valve chamber outside the valve body, for allowing the fluid in the cylinder chamber to flow downstream of the valve chamber via the external flow passage portion; a valve device provided in the outflow passage or the external flow passage portion, the valve device controlling the outflow of the fluid in the cylinder chamber to a downstream side of the valve chamber via the outflow passage; The expansion valve according to claim 2 .

10. the valve body has a low-pressure flow passage through which a fluid having a pressure lower than that in the valve chamber flows, The power element is a housing fixed to the valve body; a diaphragm provided in the housing and dividing the inside of the housing into a pressure actuated chamber and a valve chamber side chamber communicating with the low pressure flow path; a stopper member disposed in the valve-chamber side chamber and serving as the displacement portion; a locking portion provided on one of the stopper member and the syringe member; Equipped with The syringe member is disposed inside the stopper member, or the stopper member is disposed inside the syringe member, the locking portion abuts against the other of the stopper member and the syringe member to prevent the syringe member from slipping out of the stopper member or the stopper member from slipping out of the syringe member; 2. The expansion valve according to claim 1 .

11. The lower end of the housing has an inwardly extending flange portion, The syringe member has a shaft portion that is inserted into the inside of the flange portion, and a base portion that is attached to an end of the shaft portion on the power element side and has a dimension larger than that of the shaft portion, the base portion has a dimension to face the flange portion in a moving direction of the shaft portion, when the movement of the syringe member relative to the stopper member is restricted by the engaging portion, the end surface of the base on the valve chamber side is located closer to the valve chamber than the end surface of the stopper member on the valve chamber side, The flange portion and the base portion constitute the movement restricting portion.

11. The expansion valve according to claim 10.

12. The syringe member has a shaft portion and a base portion provided at one end of the shaft portion on the power element side and having a dimension larger than the shaft portion in a direction perpendicular to an axis of the shaft portion, the valve body has a hole in which the syringe member is movably disposed, The other end of the shaft portion and a bottom surface of the internal space of the hole, or the base and a surface of the valve body facing the base constitute the movement restriction portion.

2. The expansion valve according to claim 1 .

13. The syringe member has a tubular base and a shaft connected to the base, The displacement portion is slidably fitted to an inner periphery of the base portion, The shaft portion is inserted through an opening of the valve body having a smaller dimension than the base portion, The movement restriction portion is configured by the periphery of the opening.

2. The expansion valve according to claim 1 .

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