KR20120104946A - Expansion valve - Google Patents

Abstract

PURPOSE: An expansion valve is provided to close first and second valves connected to each other at the same time, thereby preventing a refrigerant leakage when closing the valves. CONSTITUTION: An expansion valve comprises a first valve(3a), a second valve(3b), a power element(17). The first valve comprises a first valve body and a first valve sheet. The second valve comprises a second valve body and a second valve sheet. The power element interlocks and controls the first valve body and a lift of the second valve body. The second valve sheet is a movable valve sheet. The movable valve sheet is adjacent to the valve body or separated from the second valve body.

Description

Expansion valve {EXPANSION VALVE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an expansion valve, and in particular, in a refrigeration cycle of an automotive air conditioning system, the refrigerant at the evaporator outlet determines the flow rate of the vapor refrigerant fed into the evaporator while thermally expanding the liquid refrigerant to form a low-temperature / low-pressure steam refrigerant. It relates to an expansion valve that controls to maintain the degree of superheat.

In an automobile air conditioning system, a compressor for compressing a refrigerant, a condenser for condensing the refrigerant, a receiver for separating the gas-liquid mixed refrigerant, an expansion valve for adiabatic expansion of the refrigerant, and an evaporator for evaporating the refrigerant, A refrigeration cycle is configured. As the expansion valve for expanding the refrigerant, a thermal expansion valve is generally used in which the flow rate of the refrigerant supplied to the evaporator is controlled in accordance with the temperature and pressure of the refrigerant at the evaporator outlet.

Since the evaporator which heat-exchanges with the air in a vehicle interior is installed in a vehicle interior, a compact thing is calculated | required. For this reason, the evaporator which laminated | stacked two heat exchangers thinned in the direction which passes air, and let a refrigerant | coolant flow through these heat exchangers in series is generally used.

The evaporator has a narrow heat exchanger, so that the passage through which the refrigerant passes is narrow, and the passage is connected in series by two heat exchangers, and thus the evaporator has a long length. Therefore, the evaporator of the said structure becomes large in the pressure loss in the passage | pass which a refrigerant | coolant passes, and the efficiency of a refrigeration cycle falls by that much.

On the other hand, the evaporator of the structure which supplies a refrigerant | coolant in parallel to each heat exchanger by making two heat exchangers independent is proposed (for example, refer patent document 1, 2). According to this evaporator, the pressure loss when a refrigerant | coolant passes through a heat exchanger falls, the net loss in the whole view of a refrigeration cycle falls, and a cooling power can be improved.

Patent documents 1 and 2 also propose expansion valves for use in such evaporators. According to this expansion valve, there is disclosed a configuration in which two valves are capable of independently adiabatic expansion of the refrigerant, and interlocked control of the two valves in accordance with the temperature and pressure of the refrigerant at the outlet of the evaporator joined with the heat exchanger.

Japanese Patent Application Laid-open No. 2010-38455, Figs. 5 and 6 International Publication No. WO2010 / 131918, FIG. 3

However, all the configurations of the expansion valve disclosed are in principle, and are not specifically shown. When the expansion valve stops the air conditioning system for automobiles, if there is a refrigerant leakage, the expansion valve generates a large amount of flow of refrigerant, and the occupant is heard as an unpleasant noise in the passengers. need. The same applies to an expansion valve having two valves, but it is important here that the two valves are closed at the same time.

This invention is made | formed in view of this point, and an object of this invention is to provide the expansion valve which can valve-close two valves which interlock | operate simultaneously.

In this invention, in order to solve the said subject, the 1st valve which has a 1st valve body and a 1st valve seat, the 2nd valve which has a 2nd valve body, and a 2nd valve seat, the said 1st valve body, and the said An expansion valve having a power element for interlocking control of a lift of a second valve body, wherein the second valve is a movable valve seat which can be adjusted in a direction in which the second valve seat is close to or spaced from the second valve body. There is provided an expansion valve.

According to this expansion valve, in the first valve and the second valve to be interlocked controlled, the second valve seat can be adjusted so that the second valve is in the valve closed state when the first valve is in the valve closed state. As a result, the two valves that interlock can be surely closed at the same time.

Since the expansion valve of the above structure can simultaneously close the first valve and the second valve to be interlocked, the refrigerant leakage at the time of closing the valve is eliminated, and therefore, the advantage of being able to reliably prevent the occurrence of the noise due to this is provided. have.

1 shows a refrigeration cycle to which the expansion valve of the present invention is applied.
2 is a longitudinal longitudinal cross-sectional view of the expansion valve according to the first embodiment.
3 is a central longitudinal cross-sectional view of the expansion valve according to the first embodiment as viewed in a direction perpendicular to the plane of FIG. 2.
4 is a central longitudinal sectional view of the expansion valve according to the second embodiment;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a view showing a refrigerating cycle to which the expansion valve of the present invention is applied.

The refrigeration cycle of the automotive air conditioning system is configured by piping the compressor 1, the condenser 2, the expansion valve 3, and the evaporator 4 in an annular shape. The compressor 1 compresses the circulating refrigerant and sends it to the condenser 2. The capacitor | condenser 2 is comprised so that the outside air may be forcibly passed by the cooling fan 5, and the compressor 1 condenses the refrigerant | coolant which became high temperature and high pressure by heat exchange with outside air. At the outlet of the condenser 2, a receiver for storing the condensed refrigerant is provided, so that the liquid refrigerant separated from the gas-liquid is supplied to the expansion valve 3.

The expansion valve 3 is a thermal expansion valve having a first valve 3a and a second valve 3b for thermally expanding the liquid refrigerant. The evaporator 4 is equipped with the 1st heat exchanger 4a and the 2nd heat exchanger 4b which are laminated | stacked and arrange | positioned in the downstream side blower of the fan 6. The first heat exchanger 4a on the side of the fan 6 is supplied with a steam refrigerant that is adiabaticly expanded from the first valve 3a of the expansion valve 3, and the second heat exchanger 4b on the outlet side is the second The adiabatic expanded steam refrigerant is supplied from the valve 3b to evaporate the refrigerant by heat exchange with the air blown by the fan 6. The refrigerant exiting the first heat exchanger 4a and the second heat exchanger 4b is joined and then returned to the compressor 1 through the expansion valve 3. When the refrigerant returned from the evaporator 4 passes through the expansion valve 3, the expansion valve 3 monitors the temperature and pressure of the refrigerant, i.e., the superheat degree of the evaporator outlet refrigerant, and according to the superheat degree, The flow rate control of the 1 valve 3a and the 2nd valve 3b is performed.

In the evaporator 4, the first heat exchanger 4a on the fan 6 side performs heat exchange with higher temperature air, and the second heat exchanger 4b on the jet port side is connected to the first heat exchanger 4a. The heat exchange is performed by the air cooled. For this reason, the flow volume of the refrigerant | coolant supplied from the 1st valve 3a to the 1st heat exchanger 4a is set so that it may become larger than the flow volume of the refrigerant | coolant supplied from the 2nd valve 3b to the 2nd heat exchanger 4b. In this embodiment, the flow rate ratio between the first valve 3a and the second valve 3b is set to 2: 1.

FIG. 2 is a central longitudinal cross-sectional view of the expansion valve according to the first embodiment, and FIG. 3 is a central longitudinal cross-sectional view of the expansion valve according to the first embodiment viewed in a direction perpendicular to the plane of FIG. 2.

The expansion valve according to the first embodiment has a body 11 of a rectangular parallelepiped, and is provided with a high pressure inlet port 12 through which a high-pressure liquid refrigerant is supplied below the drawing on one side (right side in FIG. 3). have. In the center of the side (left side in FIG. 2) adjacent to the side where the high pressure inlet port 12 of the body 11 is provided, the pipe is piped to the first heat exchanger 4a on the fan 6 side of the evaporator 4. The first low pressure outlet port 13 is provided. The body 11 is further provided with a second low pressure outlet port 14 piped to the second heat exchanger 4b on the blower outlet side below the drawing of the first low pressure outlet port 13, and has a first low pressure outlet. Above the figure of the port 13, the return refrigerant inlet port 15 is provided. The body 11 is further provided with a return refrigerant outlet port 16 above the drawing on the side where the high pressure inlet port 12 is provided.

On the upper end face of the figure of the body 11, the power element 17 which detects the superheat degree of the refrigerant | coolant returned from the evaporator 4 is screwed. In the body 11 directly below the power element 17, a shaft 18, a first valve 3a, a second valve 3b, a compression coil spring 19 and an adjust screw 20 are provided. It is arranged coaxially. These shaft 18, the 1st valve 3a, and the 2nd valve 3b are isolate | separated so that they may move independently, and even if it arrange | positions with slight misalignment of an axial center, it can move smoothly to an axial direction.

The 1st valve 3a has the 1st valve body 21 and the 1st valve seat 22 formed in the body 11, The 1st valve seat 22 has the 1st low pressure outlet port 13 ), The first valve hole 23 is drilled. The 2nd valve 3b has the 2nd valve body 24 and the 2nd valve seat 25 press-fitted into the body 11, The 1st valve hole 23 in this 2nd valve seat 25 is shown. ), The second valve hole 26 having a smaller port diameter is drilled.

The 1st valve body 21 of the 1st valve 3a is arrange | positioned so that connection and separation with respect to the 1st valve seat 22 in the valve chamber 27 which communicate with the high pressure inlet port 12 are possible. Therefore, two guides 28 which slide the inner wall of the valve chamber 27 are integrally formed in each of the first valve seat 22 side and the second valve 3b side of the first valve body 21. Formed.

The guide 28 is provided with a plurality of communication paths 29 for guiding the liquid refrigerant introduced into the valve chamber 27 toward the first valve seat 22 and the second valve 3b. This communication path 29 can be three arc-shaped opening parts arrange | positioned equally on the concentric circle in the guide 28, for example. The guide 28 further changes the length in the axial direction on the first valve seat 22 side and the second valve 3b side, so that the liquid refrigerant flows through the communication path 29 in accordance with the viscosity of the refrigerant. The force to which the 1st valve body 21 is tensioned by the 1st valve seat 22 and the 2nd valve 3b is canceled. In this embodiment, since the distribution ratio of the flow volume which the 1st valve 3a flows, and the flow volume which the 2nd valve 3b flows was 2: 1, the axial direction of the guide 28 by the side of the 1st valve seat 22 is axial direction. The ratio between the length and the axial length of the guide 28 on the second valve 3b side is 1: 2.

In the first valve 3a, the first valve body 21 is also disposed upstream of the first valve seat 22 so that the high-pressure liquid refrigerant causes the first valve body 21 to act on the valve closing side. It is structured. Thereby, although the 1st valve 3a has a proportional relationship with the pressure of the liquid refrigerant of a primary side, and the pressure of the steam refrigerant of a secondary side at the time of valve full opening, when a valve opening degree becomes smaller than either opening degree, It has a high pressure dependence characteristic that the pressure of a secondary side becomes low as the pressure of a secondary side becomes high.

The 2nd valve 3b is arrange | positioned in the coaxial space with the valve chamber 27 which communicates with the 2nd low pressure outlet port 14 from the valve chamber 27 in the body 11. As shown in FIG. The second valve seat 25 is fixed to the body 11 by press fitting, and the second valve body 24 is disposed so as to be connectable to and detachable from the second valve seat 25. The 2nd valve body 24 is integrally formed with the axial extension part 30 extended through the 2nd valve hole 26 of the 2nd valve seat 25 in the direction of the 2nd valve 3b. As for the end surface of the axial extension part 30, the 2nd valve body 24 is always in contact with the 1st valve body 21 by the pressing force by the compression coil spring 19. As shown in FIG.

In the second valve 3b, the second valve body 24 is disposed downstream of the second valve seat 25 so that the high-pressure liquid refrigerant causes the second valve body 24 to act on the valve opening side. It is structured. Therefore, this expansion valve sets the high pressure dependence characteristic which acts in a valve closing direction by the balance of the port diameter of the 1st valve hole 23 and the port diameter of the 2nd valve hole 26. As shown in FIG.

The compression coil spring 19 is accommodated by the adjust screw 20 screwed to the body 11. The load of the compression coil spring 19 is adjusted by adjusting the screw insertion amount of the adjust screw 20. This adjustment corresponds to the setting of the superheat degree which this expansion valve is trying to control. The screw mounting portion of the adjust screw 20 to the body 11 is hermetically sealed by the O-ring 31.

The power element 17 is screwed to the mounting hole formed in the upper surface of the figure of the body 11. As shown in FIG. The mounting hole of the power element 17 is in communication with the refrigerant return passage 32 formed between the return refrigerant inlet port 15 and the return refrigerant outlet port 16, so that the refrigerant passing through the refrigerant return passage 32 can be transferred. It can be introduced into the power element 17.

The power element 17 is formed by sandwiching the diaphragm 33 between the upper housing 34 and the lower housing 35 and welding their outer peripheries together. The sealed space surrounded by the diaphragm 33 and the upper housing 34 is filled with gas having characteristics similar to that of the refrigerant, and constitutes a temperature-sensitive chamber. In the lower housing 35, a disk 36 for transmitting the displacement of the diaphragm 33 to the first valve 3a and the second valve 3b is disposed. The disc 36 fits with the upper end of the shaft 18 held by the holder 37 and is centered by the shaft 18 in the lower housing 35.

The upper part of the holder 37 is installed in the mounting hole of the power element 17, and the upper part is provided with a compression coil spring 38 so as to impart a lateral load to the shaft 18 as shown in FIG. . Since the shaft 18 is restricted in axial movement by applying a lateral load, the first valve body 21 vibrates in the axial direction even if the liquid refrigerant introduced into the high pressure inlet port 12 causes a pressure fluctuation. It is suppressed to generate. The holder 37 also penetrates through the refrigerant return passage 32, and the lower end thereof is poured into the shaft 18 between the first low pressure outlet port 13 and the refrigerant return passage 32. The O-ring 39 that has been pressed is pressed. The O-ring 39 prevents the refrigerant from leaking from the first low pressure outlet port 13 to the refrigerant return passage 32 without going to the first heat exchanger 4a of the evaporator 4.

The power element 17 is covered with a cap 40 and is insulated from the surroundings so as not to be affected by the temperature of the environment in which the expansion valve is installed. A ring-shaped throttle passage member 41 is fitted into the first low pressure outlet port 13. The throttle passage member 41 has a through hole having a predetermined opening area in the center thereof, and reduces the flow rate of the refrigerant flowing out of the first low pressure outlet port 13, thereby suppressing the generation of bubbles and expanding the expansion valve. The noise passing through the refrigerant is reduced.

According to the expansion valve of the above structure, when the compressor 1 is in the stop or the minimum displacement operation, the pressure in the refrigerant return passage 32 is high, and the diaphragm 33 is detected in the power element 17 which senses this pressure. It is displaced to the temperature-sensitive chamber side. Thereby, since the 1st valve body 21 and the 2nd valve body 24 are pressurized in the valve closing direction by the compression coil spring 19, the 1st valve 3a and the 2nd valve 3b are a valve | bulb It is in a closed state.

When the compressor 1 starts to compress the refrigerant, the pressure in the refrigerant return passage 32 is lowered so that the diaphragm 33 of the power element 17 is displaced toward the first valve 3a and the second valve 3b. Thus, a high pressure refrigerant is introduced into the high pressure inlet port 12. Sooner or later, the first valve 3a and the second valve 3b are valve-opened by the power element 17, and the liquid refrigerant condensed in the condenser 2 is introduced into the high pressure inlet port 12. The liquid refrigerant introduced into the valve chamber 27 is adiabaticly expanded by the first valve 3a to become a low-temperature / low-pressure steam refrigerant, and the first heat exchanger of the evaporator 4 is discharged from the first low-pressure outlet port 13. Sent to 4a). The liquid refrigerant in the valve chamber 27 is further adiabaticly expanded by the second valve 3b to become a low temperature / low pressure steam refrigerant, and the second heat exchanger 4b of the evaporator 4 from the second low pressure outlet port 14. Is sent).

In the evaporator 4, the vapor refrigerant introduced into the first heat exchanger 4a and the second heat exchanger 4b is evaporated by heat exchange with the air blown by the fan 6, then joined and returned. Return to the refrigerant inlet port 15. The air which has passed through the evaporator 4 is dehumidified and cooled, and after it is suitably temperature-controlled, it is blown in into a compartment.

The refrigerant introduced into the return refrigerant inlet port 15 passes through the refrigerant return passage 32 and is returned to the compressor 1 from the return refrigerant outlet port 16. When the coolant from the evaporator 4 passes through the coolant return passage 32, the superheat degree of the coolant is sensed by the power element 17, and the first valve 3a and the second valve according to the superheat degree thereof. The valve lift of 3b is controlled. As a result, the flow rate of the refrigerant is controlled at the first valve 3a and the second valve 3b, respectively, to the first heat exchanger 4a and the second heat exchanger 4b of the evaporator 4 at a predetermined distribution ratio. Supplied. Since the 1st valve 3a and the 2nd valve 3b are controlled by the superheat of the refrigerant | coolant of the exit of the evaporator 4, this expansion valve transfers the flow volume of the vapor refrigerant | coolant which is supplied to the evaporator 4, and the refrigerant | coolant of the evaporator exit. Is controlled to maintain the superheat degree set by the compression coil spring 19.

4 is a central longitudinal sectional view of the expansion valve according to the second embodiment. In addition, in FIG. 4, the same code | symbol is attached | subjected about the component same as or equivalent to the component shown in FIG. 2, and the detailed description is abbreviate | omitted.

The expansion valve according to the second embodiment includes the shaft 18, the first valve 3a, the compression coil spring 19, and the adjust screw in the body 11 directly below the power element 17. 20 is arranged coaxially. The second valve 3b is arranged to valve lift in a direction perpendicular to the axial direction of the shaft 18, and the inner wall of the refrigerant passage 42 formed to cross the shaft 18 from the second low pressure outlet port 14. Is mounted on the screw. The shaft 18 has a tapered surface 43 having a truncated cone shape in the middle thereof, and the second valve 3b is in constant contact with the tapered surface 43. The O-ring 39 formed in the shaft 18 prevents the high pressure refrigerant introduced into the high pressure inlet port 12 from leaking into the refrigerant return passage 32 through the clearance of the shaft 18 and the body 11. It is preventing.

The 1st valve 3a has the ball-shaped 1st valve body 21, This 1st valve body 21 is arrange | positioned between the valve body support part 44 and the adjust screw 20 which accommodate this. It is pressurized in the valve closing direction by the compressed coil spring 19. Thereby, the 1st valve body 21 is in contact with the front-end | tip of the shaft 18 extended through the 1st valve hole 23 of the 1st valve seat 22. As shown in FIG. Since the 1st valve body 21 has a ball shape, Preferably, in order to improve assembly mountability, it is good to join to the front-end | tip of the shaft 18 by spot welding. The valve chamber 27 in which the first valve body 21 is housed communicates with the first low pressure outlet port 13, and the throttle passage member 41 is fitted in the middle thereof.

The 1st valve 3a also has the 1st valve body 21 arrange | positioned downstream of the 1st valve seat 22, and acts on the valve opening side by the high pressure liquid refrigerant, and seals the shaft 18, The O-ring 39 is subjected to a high pressure through the clearance of the shaft 18 and the body 11, and has a structure in which the shaft 18 acts in the valve closing direction. Therefore, this expansion valve sets the high pressure dependence characteristic which acts in a valve closing direction by the balance of the port diameter of the 1st valve hole 23, and the seal diameter of the O-ring 39. As shown in FIG.

The second valve 3b supports a screw engaging portion 25a in which the second valve seat 25 is screwed to the inner wall of the refrigerant passage 42 and a valve rod 24a of the second valve body 24. The groove | channel which has the valve rod support part 25b, and the valve rod support part 25b is connected to the 2nd valve hole 26 in the support hole which supports the valve rod 24a is formed. The spring support is fitted to the valve rod 24a, and the compression coil spring 45 is arrange | positioned between the spring support and the screw engaging part 25a of the 2nd valve seat 25, and the 2nd valve body While pressing 24 in the valve closing direction, the tip of the valve rod 24a is always in contact with the tapered surface 43 of the shaft 18. Thereby, the 2nd valve seat 25 becomes a movable valve seat which can be adjusted in the direction which is adjacent or spaced apart from the 2nd valve body 24 which the valve rod 24a contacts the taper surface 43, and is have. For this reason, by adjusting the screw insertion amount of the 2nd valve seat 25, it becomes possible to match the valve closing timing of the 1st valve 3a with the valve closing timing of the 2nd valve 3b. The downstream side of the second valve 3b communicates with the second low pressure outlet port 14, and the throttle passage member 46 is fitted in the middle thereof. Like the throttle passage member 41 of the first valve 3a, the throttle passage member 46 suppresses the generation of bubbles by reducing the flow rate of the refrigerant flowing out of the second low pressure outlet port 14, thereby expanding. The refrigerant passage sound of the valve is reduced.

According to the expansion valve of the above structure, when the 1st valve 3a is in the valve closed state, the valve 18 of the 2nd valve body 24 seated on the 2nd valve seat 25 ( 24a) stops at the position which exactly contacts the taper surface 43. As shown in FIG.

When the power element 17 drives in the direction to lift the 1st valve body 21 of the 1st valve 3a, the taper surface 43 of the shaft 18 will move to the direction of the 1st valve 3a. . As a result, the lift direction of the first valve body 21 is converted to the direction perpendicular to the tapered surface 43, and the second valve body 24 is lifted in conjunction with the lift of the first valve body 21. . Therefore, since the operation | movement of this expansion valve is the same as the above-mentioned operation | movement of the expansion valve which concerns on 1st Embodiment, description of operation is abbreviate | omitted.

Also in the expansion valve according to the second embodiment, similarly to the expansion valve according to the first embodiment, the refrigerant at the evaporator outlet is fed into the evaporator 4 so as to maintain the superheat degree set by the compression coil spring 19. Is controlling the flow rate of the steam refrigerant. Moreover, since the timing of valve closing of the 1st valve 3a and the 2nd valve 3b which cooperate is simultaneous, and there is no refrigerant leakage at the time of valve closing, generation of the flow noise by refrigerant leakage can be prevented completely.

1: Compressor
2: condenser
3: expansion valve
3a: first valve
3b: second valve
4: evaporator
4a: first heat exchanger
4b: second heat exchanger
5: cooling fan
6: fan
11: body
12: high pressure inlet port
13: first low pressure outlet port
14: second low pressure outlet port
15: return refrigerant inlet port
16: return refrigerant outlet port
17: power element
18: shaft
19: compression coil spring
20: adjust screw
21: first valve body
22: first valve seat
23: first valve hole
24: second valve body
24a: valve rod
25: second valve seat
26: second valve hole
27: valve chamber
28: guide
29: communication path
30: axial extension
31: O ring
32: refrigerant return passage
33: diaphragm
34: upper housing
35: lower housing
36: disk
37: holder
38: compression coil spring
39: O ring
40: cap
41: throttle passage member
42: refrigerant passage
43: tapered surface
44: valve body support
45: compression coil spring
46: throttle passage member

Claims (10)

Power for interlocking control of a first valve having a first valve body and a first valve seat, a second valve having a second valve body and a second valve seat, and a lift of the first valve body and the second valve body. An expansion valve with elements,
And said second valve is a movable valve seat which can be adjusted in a direction in which said second valve seat is close to or spaced from said second valve body. A spring for urging said power element, said first valve, said second valve and said first valve body and said second valve body in the direction of said power element is disposed coaxially. A high pressure inlet port for introducing a high pressure liquid refrigerant is communicated between the first valve and the second valve, and a first low pressure outlet port for inducing a low pressure vapor refrigerant downstream of the first valve is in communication with the second valve. A second low pressure outlet port is connected to the downstream side of the valve to lead out the low pressure vapor refrigerant, the second valve seat is press-fitted into the body constituting the first valve seat, and the press-fit amount of the second valve seat is And adjust the valve to close the first valve and the second valve at the same time. The said 1st valve body is arrange | positioned so that an advance and retraction is possible in the axial direction in the valve chamber in which the high pressure liquid refrigerant is introduce | transduced, The front end of the shaft which transmits the driving force of the said power element to the said 1st valve is The expansion valve of Claim 1 which is contacted through the 1st valve hole of a 1st valve seat, and the axial extension part of the said 2nd valve body is contacted through the 2nd valve hole of the said 2nd valve seat. The said 1st valve body is formed with the guide which slides the inner wall of the said valve chamber integrally in the said 1st valve seat side, and the said 2nd valve seat side, Each liquid guide | substrate is formed in each guide, An expansion valve, characterized in that a communication path leading to the first valve hole and the second valve hole is formed. The said 1st valve body is a ratio of the length of the axial direction of the said guide on the said 1st valve seat side, and the length of the axial direction of the said guide on the said 2nd valve seat side, The flow volume of a said 2nd valve And an expansion valve which is equal to the ratio of the flow rate of the first valve. 2. The valve closing direction according to claim 1, wherein the high pressure liquid refrigerant acts in the valve closing direction by a balance between the port diameter of the first valve acting on the valve closing side and the high pressure liquid refrigerant acting on the valve opening side. An expansion valve, characterized in that the high-pressure dependent characteristic is set. 2. The shaft of claim 1, wherein a shaft for transmitting the driving force of the power element to the first valve, a first spring for urging the first valve and the first valve body in the direction of the shaft are disposed coaxially, The second valve is disposed in a direction perpendicular to the axial direction of the shaft, and the second rod is brought into contact with the tapered surface of the truncated cone shape formed in the middle of the shaft by the pressing force of the second spring. A high pressure inlet port for interlocking the lift of the valve body with the lift of the first valve body and introducing a high pressure liquid refrigerant between the first valve and the second valve communicates with the low pressure downstream of the first valve. A first low pressure outlet port for communicating steam refrigerant of the second communication port, and a second low pressure outlet port for leading steam refrigerant of the low pressure communication state downstream of the second valve; The seat is screwed into the body constituting the first valve seat, and the screw insertion amount of the second valve seat is adjusted so that the first valve and the second valve are closed at the same time. valve. The expansion valve according to claim 7, wherein the first valve body is in contact with or joined to the tip of the shaft extending through the first valve hole of the first valve seat. 8. The liquid refrigerant according to claim 7, wherein a high pressure liquid refrigerant is poured into the port diameter of the first valve acting as the valve opening side and the shaft at a position supported by the body so that the high pressure liquid refrigerant moves the shaft to the valve closing side. An expansion valve, characterized in that the high-pressure dependent characteristic acting in the valve closing direction is set by the balance of the seal diameter of the acting zero ring. The throttle passage member of Claim 1 provided with the throttle path member which is installed in the downstream of at least one of the said 1st valve and the said 2nd valve, and suppresses generation | occurrence | production of a bubble in the refrigerant which passed the said 1st valve and the said 2nd valve, There is, expansion valve.

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