JP7182283B2 - Power element and expansion valve using the same - Google Patents

Description

The present invention relates to a power element and an expansion valve using the same.

2. Description of the Related Art Conventionally, in a refrigerating cycle used in an air conditioner or the like mounted on an automobile, a temperature-sensitive thermal expansion valve that adjusts the flow rate of refrigerant according to temperature is used. Such a thermal expansion valve employs a power element that drives the valve body with the pressure of the enclosed working gas.

The power element provided in the expansion valve disclosed in Patent Document 1 includes a diaphragm, an upper lid member forming a pressure actuation chamber in which a working gas is sealed between the diaphragm, and a through hole in the center, and the diaphragm a receiving member disposed on the opposite side of the upper lid member with respect to the upper lid member; a stopper member disposed in a fluid inflow chamber formed between the diaphragm and the receiving member and connected to an operating rod that drives the valve body; Prepare. The diaphragm is formed from a thin, flexible metal plate.

If the temperature of the refrigerant flowing into the fluid inflow chamber is low, it takes heat from the working gas in the pressure-actuated chamber and causes contraction. expansion occurs. Since the diaphragm deforms according to the contraction/expansion of the working gas, the valve body can be opened and closed via the stopper member and the operating rod according to the amount of deformation, thereby adjusting the flow rate of the refrigerant passing through the expansion valve. It can be performed.

JP 2019-163896 A

By the way, in a general refrigerating cycle, a strainer is provided in order to trap foreign matter mixed in the refrigerant flowing through the piping. However, minute foreign matter may pass through the strainer and enter the power element. In such a case, there is a possibility that foreign matter may enter between the receiving member and the diaphragm, causing local deformation of the diaphragm. On the other hand, if the strainer has the ability to trap even minute foreign matter, pressure loss in the strainer increases, which may deteriorate the efficiency of refrigerant transport in the refrigeration cycle.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a power element capable of suppressing local deformation of a diaphragm and the like, and an expansion valve using the power element, while securing refrigerant transport efficiency.

In order to achieve the above object, the power element according to the present invention comprises:
a diaphragm;
an upper lid member that abuts on the outer peripheral portion of the diaphragm and forms a pressure actuation chamber between itself and the diaphragm;
a receiving member that abuts against the outer peripheral portion of the diaphragm and forms a coolant inflow chamber between itself and the diaphragm;
a stopper member accommodated in the refrigerant inflow chamber and in contact with the diaphragm;
The diaphragm is characterized by being displaced from a neutral position within a range of positions displaced from the neutral position toward the upper cover member.

The expansion valve according to the invention comprises:
power element and
a refrigerant flow path communicating with the refrigerant inflow chamber; a valve body provided with a valve chamber and a valve seat;
a valve body arranged in the valve chamber;
a coil spring that presses the valve body toward the valve seat;
an operating rod having one end in contact with the valve body,
The power element includes a diaphragm, an upper lid member that abuts on the outer periphery of the diaphragm and forms a pressure-actuated chamber between itself and the diaphragm, and a coolant that flows into the space between the diaphragm and the outer periphery of the diaphragm. a receiving member forming a chamber;
The diaphragm is displaced from a neutral position within a range of positions displaced from the neutral position toward the upper cover member due to a pressure difference between the pressure actuation chamber and the refrigerant inflow chamber of the power element, and the coil spring is attached. It is characterized in that the valve body is driven against force.

ADVANTAGE OF THE INVENTION By this invention, the power element which can suppress the local deformation|transformation of a diaphragm, etc., and an expansion valve using the same can be provided, ensuring the conveyance efficiency of a refrigerant|coolant.

FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve of this embodiment is applied to a refrigerant circulation system. FIG. 2 is an enlarged sectional view of the power element. 3 is a cross-sectional view showing an enlarged portion A of FIG. 2. FIG. FIG. 4 is a schematic cross-sectional view showing an expansion valve in the second embodiment. FIG. 5 is a cross-sectional view of power element 8A in the second embodiment. FIG. 6 is a cross-sectional view showing an enlarged portion B of FIG. 4 in the second embodiment.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

(definition of direction)
In this specification, the direction from the valve body 3 to the operating rod 5 is defined as "upward direction", and the direction from the operating rod 5 to the valve body 3 is defined as "downward direction". Therefore, in this specification, the direction from the valve body 3 toward the operating rod 5 is referred to as the "upward direction" regardless of the orientation of the expansion valve 1 .

(First embodiment)
An outline of an expansion valve 1 including a power element in the first embodiment will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view schematically showing an example in which the expansion valve 1 of this embodiment is applied to a refrigerant circulation system 100. As shown in FIG. In this example, expansion valve 1 is fluidly connected to compressor 101 , condenser 102 and evaporator 104 . Let L be the axis of the expansion valve 1 .

In FIG. 1, an expansion valve 1 includes a valve body 2 having a valve chamber VS, a valve body 3, an urging device 4, an operating rod 5, and a power element 8.

The valve body 2 includes a first flow passage 21 , a second flow passage 22 , an intermediate chamber 221 , and a return flow passage (also referred to as a refrigerant passage) 23 in addition to the valve chamber VS. The first flow path 21 is a supply-side flow path, and refrigerant is supplied to the valve chamber VS through 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 through the valve communication hole 27, the intermediate chamber 221 and the discharge side flow path.

The first flow path 21 and the valve chamber VS are communicated with each other by a connection path 21a having a diameter smaller than that of the first flow path 21 . The valve chamber VS and the intermediate chamber 221 communicate with each other via the valve seat 20 and the valve communication hole 27 .

The actuating rod insertion hole 28 formed above the intermediate chamber 221 has the function of guiding the actuating rod 5, and the annular recess 29 formed above the actuating rod insertion hole 28 has the function of accommodating the ring spring 6. have The ring spring 6 has a plurality of spring pieces contacting the outer periphery of the operating rod 5 to apply a predetermined biasing force.

The valve body 3 is arranged in the valve chamber VS. When the valve body 3 is seated on the valve seat 20 of the valve body 2, the refrigerant flow through the valve passage hole 27 is restricted. This state is called a non-communication state. However, even when the valve body 3 is seated on the valve seat 20, a limited amount of refrigerant may flow. On the other hand, when the valve body 3 is separated from the valve seat 20, the flow of refrigerant passing through the valve hole 27 increases. This state is called a communication state.

The operating rod 5 is inserted through the valve passage hole 27 with a predetermined gap. A lower end of the operating rod 5 is in contact with the upper surface of the valve body 3 . The upper end of the operating rod 5 is fitted into a fitting hole 84c of a stopper member 84, which will be described later.

The operating rod 5 can press the valve body 3 in the valve opening direction against the biasing force of the biasing device 4 . When the operating rod 5 moves downward, the valve body 3 is separated from the valve seat 20 and the expansion valve 1 is opened.

In FIG. 1 , the biasing device 4 has a coil spring 41 formed by spirally winding a wire having a circular cross section, a valve body support 42 , and a spring receiving member 43 .

The valve body support 42 is attached to the upper end of the coil spring 41, and the spherical valve body 3 is welded to the upper surface thereof, and both are integrated.

A spring receiving member 43 that supports the lower end of the coil spring 41 can be screwed into the valve body 2 and has a function of sealing the valve chamber VS and a function of adjusting the biasing force of the coil spring 41. .

(power element)
Next, the power element 8 will be explained. FIG. 2 is an enlarged cross-sectional view of the power element 8, which is exaggerated for easy understanding of the difference from the comparative example shown by the dotted line, and may differ from the actual dimensions. Let O be the axis of the power element 8 . The power element 8 has a plug 81 , an upper lid member 82 , a diaphragm 83 , a receiving member 86 and a stopper member 84 . Also here, the upper lid member 82 side is the upper side, and the receiving member 86 side is the lower side.

The upper lid member 82 is formed, for example, by pressing a metal plate material. The upper cover member 82 includes an annular outer plate portion 82b, an outer tapered portion 82c that is continuous with the inner periphery of the outer plate portion 82b and extends upward at a shallow angle, and a deep tapered portion 82c that is continuous with the inner periphery of the outer tapered portion 82c. It has an inner tapered portion 82e directed upward and a top portion 82f that is continuous with the inner circumference of the inner tapered portion 82e. An opening 82a is formed in the center of the top portion 82f and can be sealed with a plug 81. As shown in FIG.

The receiving member 86 that faces the upper lid member 82 is formed by pressing a metal plate, for example. The receiving member 86 includes a flange portion 86a having an outer diameter substantially equal to the outer diameter of the outer plate portion 82b of the upper lid member 82, a conical portion 86b connected to the inner periphery of the flange portion 86a and directed downward, and a conical portion 86b. and a hollow cylindrical portion 86d connected to the inner periphery of the inner plate portion 86c. A male thread 86e is formed on the outer circumference of the hollow cylindrical portion 86d.

As shown in FIG. 1, a female thread 2c is formed on the inner circumference of the recessed portion 2a of the valve body 2 to which the hollow cylindrical portion 86d is attached to engage with the male thread 86e.

In FIG. 2, the diaphragm 83 arranged between the upper lid member 82 and the receiving member 86 is made of a thin and flexible metal (for example, SUS) plate material. They have approximately the same outer diameter.

More specifically, the diaphragm 83 has an outer peripheral portion 83 a sandwiched between the upper lid member 82 and the receiving member 86 and a central portion 83 b that contacts the stopper member 84 . The diaphragm 83 is coaxial with the axis O between the outer peripheral portion 83a and the central portion 83b. 83d are provided alternately along the radial direction. In the present embodiment, in the cross section shown in FIG. 2, the upper ring-shaped portion 83c and the lower ring-shaped portion 83d have a periodic shape that draws a substantially sine curve. and the lower annular portion may be independently formed on a flat plate.

FIG. 3 is a cross-sectional view showing an enlarged portion A of FIG. 2 in this embodiment, showing the displacement position of the diaphragm 83 (the solid line is the neutral position) at the time of maximum valve opening. An outer peripheral portion 83a is sandwiched between the outer plate portion 82b of the upper lid member 82 and the flange portion 86a of the receiving member 86 to hold the diaphragm 83. As shown in FIG. The outer peripheral ends of the outer plate portion 82b, the outer peripheral portion 83a, and the flange portion 86a are joined by welding as described later.

The lower ring-shaped portion 83d closest to the outer circumference of the diaphragm 83 is arranged closer to the outer circumference than the upper ring-shaped portion 83c closest to the outer circumference of the diaphragm 83, and a gap is provided between the lower ring-shaped portion 83d and the receiving member 86. is formed.

In FIG. 2, the stopper member 84 includes a cylindrical main body 84a, a disk portion 84b connected to the upper end of the main body 84a and extending in the radial direction, and a blind hole-shaped fitting formed in the center of the lower surface of the main body 84a. and a hole 84c. The disk portion 84b is in contact with the lower surface of the central portion 83b of the diaphragm 83. As shown in FIG.

Next, the procedure for assembling the power element 8 will be described. While arranging the stopper member 84 between the diaphragm 83 and the receiving member 86, the outer plate portion 82b of the upper lid member 82, the outer peripheral portion 83a of the diaphragm 83, and the flange portion 86a of the receiving member 86 are superimposed in this order. While pressing in the direction, the outer circumference is welded by TIG welding, laser welding, plasma welding, or the like to form a welded portion W over the entire circumference, and these are integrated.

Subsequently, after a working gas is introduced from an opening 82a formed in the upper lid member 82 into a space (referred to as a pressure actuation chamber PO) surrounded by the upper lid member 82 and the diaphragm 83, the opening 82a is sealed with a plug 81. Then, the stopper 81 is fixed to the upper cover member 82 by projection welding or the like.

At this time, the working gas enclosed in the pressure actuation chamber PO causes the diaphragm 83 to receive pressure in such a manner as to protrude toward the receiving member 86, so that a lower space (refrigerant inflow chamber) surrounded by the diaphragm 83 and the receiving member 86 is formed. The central portion 83b of the diaphragm 83 contacts the upper surface of the stopper member 84 arranged at the LS. As a result, the disk portion 84b of the stopper member 84 is held between the diaphragm 83 and the inner plate portion 86c of the receiving member 86. As shown in FIG.

In this embodiment, when the diaphragm 83 is displaced toward the receiving member 86 and is stopped by coming into contact with the stopper member 84, the diaphragm 83 is moved to the neutral position (or a position displaced toward the upper lid member 82 from the neutral position). be. "Neutral position" means a position where the diaphragm receives no reaction force from the fulcrum on the upper cover member side or from the fulcrum on the receiving member side.

Here, the "fulcrum on the side of the upper lid member" means a portion where the diaphragm is restrained (not displaced toward the upper lid member) by coming into contact with the upper lid member when the diaphragm is deflected and displaced, and a portion where the diaphragm is displaced toward the upper lid member. Refers to the point on the top cover member that is in contact with the boundary point with the part. In addition, the "fulcrum on the receiving member side" refers to a portion at which the diaphragm is restrained (not displaced toward the receiving member) by contact with the receiving member when the diaphragm is deflected and displaced, and a portion at which the diaphragm is displaced toward the receiving member. Refers to the point on the receiving member that touches the boundary point with the site.

Here, it is preferable that the fulcrum on the receiving member 86 side is closer to the outer circumference of the diaphragm 83 than the fulcrum on the upper lid member 82 side.

When the power element 8 assembled as described above is assembled to the valve body 2, the axis O is aligned with the axis L, and the external thread 86e on the outer periphery of the lower end of the hollow cylindrical portion 86d of the receiving member 86 is inserted into the valve body 2. 2 is screwed into a female thread 2c formed on the inner circumference of the recess 2a. When the male screw 86e of the hollow cylindrical portion 86d is screwed with respect to the female screw 2c, the inner plate portion 86c of the receiving member 86 comes into contact with the upper end surface of the valve body 2. As shown in FIG. Thereby, the power element 8 can be fixed to the valve body 2 .

At this time, a packing PK is interposed between the power element 8 and the valve body 2 to seal the space in the recess 2a connected to the lower space LS, thereby preventing leakage of refrigerant from the recess 2a. In this state, the lower space LS of the power element 8 communicates with the return channel 23 through the communication hole 2b.

(Operation of expansion valve)
An operation example of the expansion valve 1 will be described with reference to FIG. The refrigerant pressurized by the compressor 101 is liquefied by the condenser 102 and sent to the expansion valve 1 . Further, the refrigerant adiabatically expanded by the expansion valve 1 is delivered to the evaporator 104, where it exchanges heat with the air flowing around the evaporator. The refrigerant returning from the evaporator 104 is returned to the compressor 101 side through the expansion valve 1 (more specifically, the return passage 23). At this time, by passing through the evaporator 104 , the fluid pressure in the second flow path 22 becomes higher than the fluid pressure in the return flow path 23 .

The expansion valve 1 is supplied with high-pressure refrigerant from a condenser 102 . More specifically, the high pressure refrigerant from the condenser 102 is supplied to the valve chamber VS through the first flow path 21 .

When the valve body 3 is seated on the valve seat 20 (in a non-communication state), the valve body 3 is delivered from the valve chamber VS to the evaporator 104 through the valve communication hole 27, the intermediate chamber 221 and the second flow path 22. Refrigerant flow is restricted. On the other hand, when the valve body 3 is separated from the valve seat 20 (when in a communicating state), the gas flows from the valve chamber VS to the evaporator 104 through the valve communication hole 27, the intermediate chamber 221 and the second flow path 22. The flow rate of the pumped refrigerant increases. The switching between the closed state and the open state of the expansion valve 1 is performed by the operating rod 5 connected to the power element 8 via the stopper member 84 .

In FIG. 1, inside the power element 8, a pressure actuation chamber PO and a lower space LS, which are partitioned by a diaphragm 83, are provided. Therefore, when the working gas in the pressure working chamber PO is liquefied, the diaphragm 83 and the stopper member 84 rise, so that the working rod 5 moves upward according to the biasing force of the coil spring 41 . On the other hand, when the liquefied working gas is vaporized, the diaphragm 83 and the stopper member 84 are pressed downward, so that the working rod 5 moves downward. Thus, the expansion valve 1 is switched between the open state and the closed state.

Furthermore, the lower space LS of the power element 8 communicates with the return channel 23 . Therefore, the volume of the working gas in the pressure working chamber PO changes according to the temperature and pressure of the refrigerant flowing through the return passage 23, and the working 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 toward the evaporator 104 is automatically adjusted according to the temperature and pressure of the refrigerant returning from the evaporator 104 to the expansion valve 1. adjusted.

(Comparative example)
Next, the effect of this embodiment will be described with reference to a comparative example. In FIG. 2, for ease of understanding, a stopper member 84A (indicated by a dotted line) according to the comparative example is shown superimposed on the stopper member 84 of the present embodiment. A stopper member 84A according to the comparative example differs from the stopper member 84 of the present embodiment only in the thickness of the disk portion. More specifically, the thickness t _A of the disk portion 84Ab of the stopper member 84A is smaller than the thickness t of the disk portion 84b of the stopper member 84 (t<t _A ). The power element 8A of the comparative example has the same shape as the power element 8 of the present embodiment except for the shape of the stopper member 84A.

In the power element 8A of the comparative example, when the working gas in the pressure working chamber PO expands and the diaphragm 83 is displaced toward the receiving member 86 and is stopped by coming into contact with the stopper member 84 (that is, when the maximum valve opening 2), the disk portion 84Ab is sandwiched between the diaphragm 83 and the inner plate portion 86c of the receiving member 86 as indicated by the dotted line in FIG. At this time, since the thickness _tA of the disk portion 84Ab is relatively thin, the diaphragm 83 is at a position displaced from the neutral position toward the receiving member 86 side. Therefore, as indicated by the dotted line in FIG. 3, the diaphragm 83 is displaced toward the receiving member 86 and receives a reaction force from the fulcrum P1 on the receiving member 86 side. In other words, the diaphragm 83 is displaced around the fulcrum P1 on the receiving member 86 side from the neutral position, thereby increasing or decreasing the gap between the diaphragm 83 and the receiving member 86 .

Here, foreign matter DS such as metal powder mixed in the refrigerant may enter the lower space LS through the return flow path 23 during operation of the refrigerant circulation system 100 . In such a case, as shown in FIG. 3, the foreign matter DS enters the gap between the diaphragm 83 and the receiving member 86, and when the diaphragm 83 is displaced toward the receiving member 86, the foreign matter DS is caught between the receiving member 86 and the diaphragm 83. may occur. Since the diaphragm 83 is made of a very thin metal plate, if a relatively hard foreign object DS is caught in the diaphragm 83, stress concentration will occur, causing local deformation and the like, and depending on the situation, the operating characteristics of the power element 8 will be deteriorated. There is a risk of

On the other hand, according to this embodiment, when the diaphragm 83 is displaced toward the receiving member 86 and is stopped by coming into contact with the disk portion 84b of the stopper member 84, the diaphragm 83 is moved as shown by the solid line in FIG. is in the neutral position (or a position displaced from the neutral position toward the upper lid member 82). In other words, the diaphragm 83 is displaced with the fulcrum P2 on the side of the upper lid member 82 as a base point only within a range from the neutral position to the side of the upper lid member 82 between the maximum valve opening and the valve closing. In other words, since the diaphragm 83 is not displaced from the neutral position toward the receiving member 86, even if the foreign matter DS enters the gap between the diaphragm 83 and the receiving member 86, the gap does not become smaller, so that the foreign matter does not get caught. does not occur, and no local deformation of the diaphragm 83 occurs. As a result, a normal strainer (not shown) can be used in the refrigerant circulation system 100, and the efficiency of conveying the refrigerant is not lowered.

(Second embodiment)
FIG. 4 is a schematic cross-sectional view showing an expansion valve 1A according to the second embodiment. FIG. 5 is a cross-sectional view of power element 8A in the second embodiment. FIG. 6 is a cross-sectional view showing an enlarged portion B of FIG. 4 in the second embodiment.

The expansion valve 1A shown in FIG. 4 differs from the expansion valve 1 according to the first embodiment in the power element 8A and the upper structure of the valve main body 2A. That is, in this embodiment, the power element 8A and the valve body 2A are not connected by screwing, but are connected by caulking. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and redundant explanations are omitted.

In FIG. 5, the power element 8A has a plug 81, an upper lid member 82, a diaphragm 83, a receiving member 86A and a stopper member 84. Also here, the upper lid member 82 side is the upper side, and the receiving member 86A side is the lower side. Although the stopper member may not be provided, in that case, it is preferable to provide a restraining member for restraining displacement of the diaphragm instead of the stopper member. A portion of the receiving member 86A may be deformed to replace the stopper member.

A power element 8A of the present embodiment differs from the power element 8 of the first embodiment mainly only in the configuration of a receiving member 86A. Other than that, the plug 81, the upper lid member 82, the diaphragm 83, and the stopper member 84 have basically the same configuration except for the shape of the details, so they are denoted by the same reference numerals and will not be described repeatedly.

The receiving member 86A, which is formed by pressing a metal plate material, includes a flange portion 86Aa having an outer diameter substantially equal to the outer diameter of the outer plate portion 82b of the upper lid member 82, and a flange portion 86Aa connected to the inner periphery of the flange portion 86Aa. A downward conical portion 86Ab, an annular intermediate plate portion 86Ac connected to the inner circumference of the conical portion 86Ab, a hollow cylindrical portion 86Ad connected to the inner circumference of the intermediate plate portion 86c, and a hollow cylinder and an annular inner plate portion 86Ae that is continuous with the inner circumference of the portion 86Ad. The inner plate portion 86Ae has a central opening 86Af into which the main body 84a of the stopper member 84 is fitted.

When assembling the power element 8A, while the stopper member 84 is arranged between the diaphragm 83 and the receiving member 86A, the outer plate portion 82b of the upper lid member 82, the outer peripheral portion 83a of the diaphragm 83, and the flange portion of the receiving member 86A are assembled. 86Aa are overlapped in this order and pressed in the axial direction, and the outer periphery thereof is welded by, for example, TIG welding, laser welding, or plasma welding to form a welded portion W over the entire periphery, and these are integrated.

Subsequently, after the working gas is sealed from the opening 82a formed in the upper lid member 82 into the space surrounded by the upper lid member 82 and the diaphragm 83, the opening 82a is sealed with the plug 81, and projection welding or the like is used. to fix the stopper 81 to the upper lid member 82 . As described above, the power element 8A is assembled.

In FIG. 6, a valve body 2A made of metal such as aluminum has a circular tubular portion 2d extending from its upper end. The inner diameter of the circular tube portion 2d is equal to or slightly larger than the outer diameter of the power element 8A.

Before the power element 8A is assembled to the valve main body 2A, the circular tube portion 2d has a cylindrical shape with the axis L (FIG. 4) as the axis, as indicated by the dotted line. When assembling the power element 8A to the valve main body 2A, an annular packing PK is placed on the stepped portion 2e of the valve main body 2A and brought close to the valve main body 2A from the receiving member 86A side, so that the power element 8A is inserted into the circular tube portion 2d. mating. At this time, the packing PK is sandwiched between the intermediate plate portion 86Ac and the stepped portion 2e.

In this state, when the tip of the circular pipe portion 2d is crimped inward using a crimping tool (not shown), the tip of the circular pipe portion 2d is plastically deformed toward the axis L, forming an annular crimped portion 2f. is formed. The outer peripheral upper surface of the outer plate portion 82b of the upper lid member 82 is pressed and fixed by the crimped portion 2f. As a result, the packing PK is compressed in the direction of the axis L between the intermediate plate portion 86Ac and the stepped portion 2e, sealing the space in the recessed portion 2a connected to the lower space LS, thereby preventing refrigerant leakage from the recessed portion 2a. .

The expansion valve 1A shown in FIG. 4 can also be incorporated into the refrigerant circulation system 100 shown in FIG. 1, and exhibits the same function as the expansion valve 1 according to the first embodiment.

Note that the present invention is not limited to the above-described embodiments. Variations of any of the components of the above-described embodiments are possible within the scope of the invention. Also, arbitrary components can be added or omitted in the above-described embodiments. For example, in the present embodiment, the position of the diaphragm at maximum valve opening is defined as the neutral position, but a position displaced toward the upper cover member from the neutral position may be defined as maximum valve opening.

1, 1A: Expansion valves 2, 2A: Valve body 3: Valve body 4: Biasing device 5: Operating rod 6: Ring spring 8, 8A: Power element 20: Valve seat 21: First flow path 22: Second flow Path 221 : Intermediate chamber 23 : Return flow path 27 : Valve passage hole 28 : Operating rod insertion hole 29 : Annular recess 41 : Coil spring 42 : Valve body support 43 : Spring receiving member 81 : Stopper 82 : Top lid member 83 : Diaphragm 84 : Stopper members 86, 86A : Receiving member 100 : Refrigerant circulation system 101 : Compressor 102 : Condenser 104 : Evaporator VS : Valve chamber

Claims (5)

a diaphragm;
an upper lid member that abuts on the outer peripheral portion of the diaphragm and forms a pressure actuation chamber between itself and the diaphragm;
a receiving member that abuts against the outer peripheral portion of the diaphragm and forms a coolant inflow chamber between itself and the diaphragm;
a stopper member accommodated in the refrigerant inflow chamber and in contact with the diaphragm;
A power element, wherein the diaphragm is displaced from a neutral position within a range of positions displaced from the neutral position toward the upper cover member. 2. The diaphragm according to claim 1, wherein said diaphragm is stopped by said receiving member via said stopper member within a range of a position displaced from said neutral position toward said upper cover member from said neutral position. power element. 3. The power element according to claim 1, wherein the fulcrum on the receiving member side is closer to the outer circumference of the diaphragm than the fulcrum on the upper cover member side. power element and
a refrigerant flow path communicating with the refrigerant inflow chamber; a valve body provided with a valve chamber and a valve seat;
a valve body arranged in the valve chamber;
a coil spring that presses the valve body toward the valve seat;
an operating rod having one end in contact with the valve body,
The power element includes a diaphragm, an upper lid member that abuts on the outer periphery of the diaphragm and forms a pressure-actuated chamber between itself and the diaphragm, and a coolant that flows into the space between the diaphragm and the outer periphery of the diaphragm. a receiving member forming a chamber;
The diaphragm is displaced from a neutral position within a range of positions displaced from the neutral position toward the upper cover member due to a pressure difference between the pressure actuation chamber and the refrigerant inflow chamber of the power element, and the coil spring is attached. An expansion valve characterized by driving the valve body against force. The power element is housed in the refrigerant inflow chamber and has a stopper member that contacts the diaphragm,
5. The diaphragm according to claim 4, wherein said diaphragm is stopped by said receiving member via said stopper member within a range of positions displaced from said neutral position toward said upper cover member from said neutral position. expansion valve.

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