JP2006292185A - Expansion device and refrigerating cycle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To sense the temperature of the outlet of an external heat exchanger by an expansion device, throttle-expand a refrigerant, and supply it to an evaporator without especially limiting the pipe shape of a refrigerating cycle and the shape of an internal heat exchanger. <P>SOLUTION: This expansion device 3, a temperature sensitive cylinder 9 installed in the outlet of a gas cooler and a body 7 installed at the downstream-side end of the internal heat exchanger 6 are arranged independently, and connected through a tube 10. An internal liquid material expands or contracts based on the temperature of the refrigerant on the upstream side sensed by the temperature sensitive cylinder 9, and is transmitted to a temperature sensitive chamber 28 of the body 7 via the tube 10. A diaphragm 26 is displaced to make a differential pressure regulating valve 17 operate in valve closing/opening directions. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle applied to an air conditioner, and an expansion device constituting the refrigeration cycle.

  The refrigeration cycle of an automotive air conditioner includes a receiver that performs gas-liquid separation of refrigerant condensed by a condenser (external heat exchanger) and a refrigeration cycle that uses a temperature-type expansion valve that expands the separated liquid refrigerant. In addition, a refrigeration cycle using an orifice tube that squeezes and expands the refrigerant condensed by a condenser and an accumulator that performs gas-liquid separation of the refrigerant evaporated by an evaporator is known. Since the orifice tube is composed of a small-diameter tube, it has an advantage that the structure is simple, the manufacturing cost is low, and the degree of freedom in layout is high. However, unlike the temperature expansion valve, the refrigeration cycle using an orifice tube has a refrigerant flow rate control function because it squeezes and expands the refrigerant only with a small-diameter tube, and operates the refrigeration cycle efficiently in all situations. I can't.

On the other hand, for example, it is applied to a refrigeration cycle using CO ₂ as a refrigerant, and the sectional area of the throttle passage of the orifice in which the refrigerant is throttled according to the pressure and temperature of the refrigerant on the outlet side of the gas cooler (external heat exchanger) is variable. There has been proposed an expansion device that can efficiently operate a refrigeration cycle (see, for example, Patent Document 1).

  According to this expansion device, a sealed space in which a predetermined refrigerant is enclosed and partitioned by a diaphragm to detect the pressure and temperature of the refrigerant introduced from the gas cooler is provided on the upstream side of the valve hole, and the valve is displaced by the displacement of the diaphragm. It has a valve structure that opens and closes the hole from the upstream side. Thereby, when the pressure of the introduced refrigerant is lower than the pressure of the sealed space corresponding to the temperature of the refrigerant, the valve hole is closed. Then, when the pressure of the introduced refrigerant becomes higher than the pressure of the sealed space by a predetermined pressure, the valve hole starts to open, and when the differential pressure between the pressure of the introduced refrigerant and the pressure of the sealed space becomes larger than the predetermined pressure, Opening according to the differential pressure. As a result, the refrigerant pressure and temperature at the gas cooler outlet side are controlled along the optimal control line determined from the refrigerant temperature at the gas cooler outlet side and the pressure that maximizes the coefficient of performance, enabling efficient operation of the refrigeration cycle. I have to.

In such a refrigeration cycle, an internal heat exchanger is often provided between the gas cooler and the evaporator (see, for example, Patent Document 2).
Thereby, heat exchange between the refrigerant flowing from the gas cooler toward the evaporator and the refrigerant flowing from the accumulator toward the compressor is performed, and the heat exchange efficiency in the refrigeration cycle is improved.
JP-A-9-264622 (FIG. 4) Japanese Patent Laying-Open No. 2001-201213 (FIG. 1)

However, in the configuration in which an internal heat exchanger is provided as in Patent Document 2, an attempt to configure an expansion device that realizes the function described in Patent Document 1 has the following problems.
That is, the expansion device squeezes and expands the refrigerant led to the evaporator, and therefore must be arranged downstream of the internal heat exchanger. On the other hand, it is necessary to sense the temperature of the gas cooler outlet. Must be located upstream of the heat exchanger. For this reason, when the expansion device is provided in a pipe on the downstream side of the internal heat exchanger, it is necessary to bring this pipe close to the pipe on the upstream side of the internal heat exchanger. Further, when the expansion device is integrally provided at the downstream end portion of the internal heat exchanger for simplifying the structure, the internal heat exchanger itself or its internal refrigerant passage is bent in a U-shape, etc. It is necessary to forcibly arrange the temperature sensing unit upstream of the internal heat exchanger. For this reason, there existed a problem that the shape of the piping of a refrigerating cycle and the shape of an internal heat exchanger would be restrict | limited.

Such a problem can be said not only for the expansion device that senses the temperature of the gas cooler outlet, but also for the expansion device that senses the temperature of the condenser outlet.
The present invention has been made in view of the above points, and the temperature of the outlet of the external heat exchanger is set without particularly limiting the piping shape of the refrigeration cycle including the internal heat exchanger and the shape of the internal heat exchanger. An object of the present invention is to provide an expansion device that can detect and expand the refrigerant and supply it to an evaporator, and a refrigeration cycle including the expansion device.

  In the present invention, in order to solve the above problem, in an expansion device that squeezes and expands the refrigerant circulating in the refrigeration cycle, the upstream pressure at which the refrigerant is introduced and the downstream pressure at which the expanded refrigerant is derived A differential pressure valve that acts in the valve opening direction as the differential pressure increases, and a liquid material having a thermal expansion coefficient equal to or greater than a preset value is sealed and attached to a pipe disposed on the upstream side, thereby A temperature sensing cylinder that senses the temperature of the refrigerant on the side, a temperature sensing chamber that communicates with the inside of the temperature sensing cylinder via a tube, and is filled with the liquid material therein, and the temperature of the refrigerant on the upstream side And a power element that causes the differential pressure valve to act in a valve closing direction via a flexible member that forms the temperature-sensitive room.

  According to such an expansion device, the liquid material inside expands or contracts based on the temperature of the refrigerant on the upstream side detected by the temperature sensing cylinder and is transmitted to the temperature sensing chamber via the tube, and the flexible member is displaced. Thus, the differential pressure valve is operated in the valve closing or valve opening direction. The temperature sensing chamber for operating the differential pressure valve and the temperature sensing cylinder for sensing temperature are connected to each other via a tube, but can be arranged independently. For this reason, even if this expansion device is provided on the downstream side or downstream end of the internal heat exchanger of the refrigeration cycle, the external heat exchanger is not particularly limited to the piping shape of the refrigeration cycle or the shape of the internal heat exchanger. The refrigerant can be squeezed and expanded by sensing the temperature of the outlet and supplied to the evaporator.

  In particular, since the encapsulating material in the temperature-sensitive greenhouse is a liquid material, the thermal expansion in the temperature-sensitive cylinder can be transmitted to the temperature-sensitive room more quickly than in the case of gas or gas-liquid mixture, and the responsiveness of the operation of the differential pressure valve is improved. Can be better.

  In the present invention, the compressor that compresses the refrigerant, the external heat exchanger that cools the compressed refrigerant, the expansion device that squeezes and expands the cooled refrigerant, the evaporator that evaporates the expanded refrigerant, and the surplus in the refrigeration cycle An accumulator that stores the refrigerant and separates the vapor-phase refrigerant from the evaporated refrigerant and sends the refrigerant to the compressor, and between the refrigerant that flows from the external heat exchanger to the expansion device and the refrigerant that flows from the accumulator to the compressor In the refrigeration cycle including an internal heat exchanger that performs heat exchange at the body, the expansion device includes a body integrally attached to a downstream end portion of the internal heat exchanger, and is provided in the body, and refrigerant is introduced. Acting in the valve opening direction as the differential pressure between the upstream pressure and the downstream pressure from which the expanded refrigerant is derived increases A pressure material and a liquid material having a thermal expansion coefficient equal to or higher than a preset value are enclosed, and attached to a pipe connecting the external heat exchanger and the internal heat exchanger, thereby controlling the temperature of the refrigerant on the upstream side. A temperature sensing cylinder for sensing, a temperature sensing chamber provided in the body, communicating with the inside of the temperature sensing cylinder via a tube, and filled with the liquid material therein, and the temperature of the refrigerant on the upstream side is There is provided a refrigeration cycle comprising a power element that causes the differential pressure valve to act in a valve closing direction through a flexible member that forms the temperature-sensitive room as the size increases.

  In such a refrigeration cycle, in the expansion device, the liquid material inside expands or contracts based on the temperature of the upstream refrigerant sensed by the temperature sensing cylinder, and is transferred to the temperature sensing greenhouse via the tube. The member is displaced to cause the differential pressure valve to act in the valve closing or valve opening direction. The temperature sensing chamber for operating the differential pressure valve of the expansion device and the temperature sensing cylinder for sensing temperature are connected to each other via a tube, but can be arranged independently. For this reason, in this refrigeration cycle, even if the expansion device is provided on the downstream side or the downstream end of the internal heat exchanger, the shape of the pipe connecting the external heat exchanger, the internal heat exchanger, and the evaporator, and the internal heat exchanger The shape is not particularly limited.

  In particular, since the encapsulating material in the temperature-sensitive greenhouse is a liquid material, the thermal expansion in the temperature-sensitive cylinder due to sensing of the temperature at the outlet of the external heat exchanger can be quickly transmitted to the temperature-sensitive room, and the responsiveness of the operation of the differential pressure valve can be improved. Can be better.

  According to the expansion device of the present invention, the temperature-sensitive greenhouse and the temperature-sensitive cylinder are connected via the tube, but can be arranged independently of each other. For this reason, even if this expansion device is provided on the downstream side or the downstream end of the internal heat exchanger of the refrigeration cycle, the upstream side temperature is not particularly limited without restricting the shape of the piping of the refrigeration cycle or the shape of the internal heat exchanger. The refrigerant can be squeezed and expanded to be supplied to the evaporator.

  Further, according to the refrigeration cycle of the present invention, the temperature-sensitive greenhouse of the expansion device and the temperature-sensitive cylinder are connected via the tube, but can be arranged independently of each other. For this reason, even if this expansion device is provided on the downstream side or downstream end of the internal heat exchanger, the temperature sensing cylinder can be freely arranged, and the piping shape of the refrigeration cycle and the shape of the internal heat exchanger are particularly limited. There is nothing to do.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, the refrigeration cycle of the present invention is applied to an automotive air conditioner, and is configured as a supercritical refrigeration cycle using carbon dioxide (CO ₂ ) as a refrigerant. FIG. 1 is a system configuration diagram showing a refrigeration cycle according to the present embodiment.

  The refrigeration cycle of the present embodiment is driven by an automobile engine and compresses the refrigerant to a supercritical region, and a gas cooler 2 that cools the refrigerant discharged from the compressor 1 (corresponds to an “external heat exchanger”). The expansion device 3 that squeezes and expands the refrigerant delivered from the gas cooler 2, the evaporator 4 that evaporates the refrigerant that has passed through the expansion device 3, and the excess refrigerant in the refrigeration cycle is stored. In addition, the accumulator 5 that separates the gas-phase refrigerant from the refrigerant evaporated by the evaporator 4 and sends the refrigerant to the compressor 1, the refrigerant sent from the gas cooler 2 to the expansion device 3, and the refrigerant sent from the accumulator 5 to the compressor 1, And an internal heat exchanger 6 that performs heat exchange between the two.

  That is, in the internal heat exchanger 6, the refrigerant flowing from the gas cooler 2 toward the evaporator 4 is cooled by the refrigerant flowing from the accumulator 5 toward the compressor 1, while the refrigerant flowing from the accumulator 5 toward the compressor 1 is It is heated by the refrigerant flowing from the gas cooler 2 toward the evaporator 4. This increases the heat exchange rate of the refrigeration cycle.

  The main body 7 of the expansion device 3 is integrally provided at the downstream end position of the internal passage connecting the gas cooler 2 and the evaporator 4 in the internal heat exchanger 6, and the upstream pipe of the internal heat exchanger 6 is provided. 8 is attached with a temperature sensing cylinder 9 constituting the expansion device 3. The main body 7 and the temperature sensitive cylinder 9 are connected by a tube 10.

Next, the configuration of the expansion device according to the present embodiment will be described in detail. FIG. 2 is a partial cross-sectional view showing the configuration of the expansion device and its periphery.
A housing part 11 for housing the main body 7 of the expansion device 3 is provided at the downstream end of the internal heat exchanger 6 as described above. An internal passage 12 that leads from the gas cooler 2 to the evaporator 4 is communicated with the housing portion 11 so as to traverse. After the main body 7 is accommodated in the accommodating portion 11, the fixing plate 13 disposed so as to cover the opening of the accommodating portion 11 from the outside is screwed to the body of the internal heat exchanger 6, so that the internal heat Fixed to the exchanger 6. The airtightness between the main body 7 and the accommodating portion 11 is held by O-rings 14 and 15 interposed therebetween. The refrigerant introduced into the main body 7 from the high-pressure passage 16 on the upstream side of the internal passage 12 of the internal heat exchanger 6 is expanded and decompressed by a differential pressure valve 17 provided inside the main body 7, It is led out from the low pressure passage 18 on the downstream side to the evaporator 4 side. The detailed configuration of the main body 7 of the expansion device 3 will be described later.

  The temperature sensing cylinder 9 includes a cylindrical main body 19 with both ends contracted. One end of the tube 10 is press-fitted into one end, and a closed tube 20 with the tip closed is press-fitted into the other end. The main body 19 is attached by welding or the like so that the side wall thereof is in close contact with the side wall of the pipe 8. A material (alcohol such as ethylene glycol in this embodiment) is enclosed. This liquid material is also filled in the after-sensing greenhouse of the expansion device 3 that communicates with the inside of the main body 19 via the tube 10.

FIG. 3 is an enlarged cross-sectional view illustrating the configuration of the main body of the expansion device. In the following description, for convenience, it may be expressed as upper and lower with reference to the illustrated state.
The main body 7 of the expansion device 3 includes a stepped cylindrical body 21, and an inlet port 22 for introducing the refrigerant from the upstream side and a discharge port 23 for leading the refrigerant to the downstream side are provided on the side of the body 21. Is formed. A power element 24 is provided at the upper end opening of the body 21, and the differential pressure valve 17 is disposed inside the body 21.

  The power element 24 includes a cup-shaped lid member 25 having a flange portion at the outer peripheral end, and a diaphragm 26 (“flexible” made of a flexible metal thin plate disposed so as to close the lower opening of the lid member 25. And a ring-shaped fixing member 27 disposed so as to sandwich the outer peripheral portion of the diaphragm 26 with the flange portion of the lid member 25. The joint between the flange portion of the lid member 25 and the fixing member 27 sandwiching the diaphragm 26 is welded all around, and a temperature sensitive chamber 28 is formed inside the lid member 25. After the power element 24 is attached to the upper end opening of the body 21, the opening end thereof is crimped inward so that the power element 24 is fixed so as to be sandwiched between the upper ends of the body 21.

  A circular hole 29 is formed at the center of the upper end surface of the lid member 25, and the other end of the tube 10 is joined thereto. As a result, the temperature sensing chamber 28 communicates with the inside of the temperature sensing tube 9 via the internal passage of the tube 10, and the liquid material described above can go back and forth between the temperature sensing tube 9, the tube 10 and the temperature sensing chamber 28. It is full.

  The differential pressure valve 17 includes a bottomed cylindrical valve body 31 and a stepped columnar valve seat forming member 32. The valve body 31 is configured such that a stepped columnar disk 34 is press-fitted into an upper end opening of a cylindrical main body 33 to form a bottom portion thereof. The disk 34 is joined to the lower end surface of the diaphragm 26 at its upper end surface (that is, the end surface opposite to the main body 33), and the main body 33 extends along a guide hole 35 provided in the central portion of the body 21. It is supported so that it can advance and retreat in the axial direction. The lower end of the main body 33 has a tapered shape in which the inner diameter increases downward, and the tip portion constitutes a valve portion 36 that is attached to and detached from the valve seat forming member 32. Further, an opening 37 is formed in the side of the main body 33 near the lower end of the disk 34, and the internal refrigerant passage and the introduction port 22 are communicated with each other.

Between the disk 34 and the body 21, a spring 38 (corresponding to "other urging means") for urging the valve body 31 toward the diaphragm 26, that is, in the valve opening direction is provided.
The valve seat forming member 32 includes a main body 39 guided along the inner wall of the lower opening of the body 21, and is disposed to face the valve body 31 in the axial direction. The upper half of the main body 39 has a slightly smaller outer diameter, and receives the pressure of the high-pressure refrigerant at the tip surface. Moreover, the outer peripheral part of the front end surface has a tapered shape that is inclined toward the valve body 31 as it goes outward, and the valve seat part 40 to which the valve part 36 is attached and detached is formed by the tapered surface. A portion where the valve portion 36 and the valve seat portion 40 are in contact with and separated from each other is exposed to the derivation port 23, and a throttle flow that allows the introduction port 22 and the derivation port 23 to communicate with each other through a gap between the valve portion 36 and the valve seat portion 40. A path is formed.

  A stepped cylindrical spring receiver 41 is fitted into the lower end portion of the body 21. Between the valve seat forming member 32 and the spring receiver 41, a spring 42 (corresponding to “biasing means”) for biasing the valve seat forming member 32 in the valve body 31 side, that is, in the valve opening direction is interposed. ing. Further, the central portion of the spring receiver 41 protrudes toward the valve seat forming member 32, and its tip constitutes a locking surface 43 for locking the valve seat forming member 32. For this reason, even if the valve seat forming member 32 receives a large force in the valve opening direction and moves in the axial direction, the displacement in the valve opening direction is restricted by the locking surface 43. A communication hole 45 is formed in the center of the locking surface to communicate the inside and outside of the pressure space 44 sandwiched between the valve seat forming member 32 and the spring receiver 41. The pressure space 44 communicates with the low-pressure passage 18 through a refrigerant passage formed between the lower portion of the body 21 and the accommodating portion 11 of the internal heat exchanger 6 and a communication hole 45. For this reason, the pressure of the low-pressure refrigerant decompressed by the expansion device 3 is introduced into the lower end surface (the surface opposite to the valve body 31) of the valve seat forming member 32 (see FIG. 2).

Further, sealing grooves 46 and 47 for attaching the above-described O-rings 14 and 15 are respectively provided on the side surfaces near the upper end portion and the center portion of the body 21.
Next, based on FIG.1 and FIG.2, operation | movement of the expansion apparatus 3 is demonstrated.

  The high-temperature and high-pressure gas refrigerant exiting the gas cooler 2 is introduced into the internal heat exchanger 6 through the pipe 8. Then, after the heat is exchanged in the internal heat exchanger 6, the heat is introduced from the high-pressure passage 16 into the introduction port 22 of the expansion device 3.

  At this time, in the expansion device 3, the valve seat forming member 32 is pushed down in the valve opening direction against the urging force of the spring 42 by the pressure of the introduced high-pressure refrigerant, while the valve body 31 is moved in the valve opening direction by the spring 38. Since it is energized, the differential pressure valve 17 is opened. At this time, the valve seat forming member 32 has a valve opening direction force due to a differential pressure (P1-P2) between the pressure P1 of the upstream high-pressure refrigerant and the pressure P2 of the downstream low-pressure refrigerant, and the valve closing direction by the spring 42. It is held at a position where it balances with other forces. Further, the temperature sensing cylinder 9 senses the temperature of the gas refrigerant flowing through the pipe 8, and when the temperature of the gas refrigerant is high, the liquid material inside expands and is displaced to the temperature sensing chamber 28 via the tube 10, The diaphragm 26 is displaced to the valve body 31 side. For this reason, the valve body 31 moves against the biasing force of the spring 38 in the valve closing direction (that is, the valve seat forming member 32 side). On the other hand, when the temperature of the gas refrigerant is low, the liquid material inside contracts, so that the diaphragm 26 is displaced to the side opposite to the valve body 31. For this reason, the valve body 31 is moved in the valve opening direction (that is, the side opposite to the valve seat forming member 32) by the urging force of the spring 38.

  That is, the valve opening degree of the differential pressure valve 17 (that is, the cross-sectional area of the throttle channel) is controlled to a magnitude based on the differential pressure before and after the refrigerant temperature at the outlet of the gas cooler 2, and opens as the differential pressure increases. As the refrigerant temperature at the outlet of the gas cooler 2 increases, it acts in the valve closing direction. Thereby, the expansion device 3 can control the high pressure so that the efficiency becomes maximum with respect to the refrigerant temperature at the outlet of the gas cooler 2. At this time, the refrigerant expanded and contracted by the expansion device 3 is introduced into the evaporator 4 through a predetermined pipe.

  As described above, in the expansion device 3 of the present embodiment, the temperature sensing tube 9 installed at the outlet of the gas cooler 2 and the main body 7 installed at the downstream end of the internal heat exchanger 6 are mutually connected. They are arranged independently and connected by a tube 10. Then, the liquid material inside expands or contracts based on the temperature of the upstream refrigerant detected by the temperature sensing cylinder 9 and is transmitted to the temperature sensing chamber 28 of the main body 7 through the tube 10, and the diaphragm 26 is displaced. The pressure valve 17 is operated in the valve closing or valve opening direction.

  For this reason, according to the expansion device 3, even if the main body 7 is provided at the downstream end of the internal heat exchanger 6 by adjusting the length and arrangement of the tube 10, the piping shape of the refrigeration cycle and the internal heat exchange Without particularly limiting the shape of the internal passage of the vessel 6, the temperature of the outlet of the gas cooler 2 can be sensed to expand the refrigerant and supply it to the evaporator 4.

  In particular, since the encapsulating material of the temperature sensitive chamber 28 and the temperature sensing tube 9 is a liquid material connected inside, the shrinkage rate due to pressure is smaller than that of gas or gas-liquid mixed material, and it has excellent thermal expansion or contraction transferability. ing. For this reason, the temperature change detected by the temperature sensing cylinder 9 can be quickly transmitted to the temperature sensing chamber 28, and the responsiveness of the operation of the differential pressure valve 17 can be improved.

  In this embodiment, alcohol is used as the liquid material sealed in the temperature sensing tube 9, but other liquid materials can be used as long as the thermal expansion can be appropriately and quickly transmitted to the temperature sensitive chamber 28. You can also.

  In the present embodiment, the metal diaphragm 26 is used as the flexible member, but a diaphragm made of a material other than metal can also be used. In addition, other flexible members such as bellows can be used instead of the diaphragm.

  Moreover, in this Embodiment, although the structure which provided the main body 7 of the expansion apparatus 3 integrally in the downstream end part of the internal heat exchanger 6 was shown, the main body 7 is the downstream of the internal heat exchanger 6, ie, You may make it provide in the middle of piping which connects the internal heat exchanger 6 and the evaporator 4. FIG.

  Furthermore, in the present embodiment, an example in which the present invention is applied to a supercritical refrigeration cycle using carbon dioxide as a refrigerant has been described. However, the present invention can also be applied to a refrigeration cycle using a refrigerant other than carbon dioxide. In that case, a condenser may be used instead of the gas cooler 2 as an external heat exchanger.

It is a system configuration figure showing the refrigerating cycle concerning an embodiment. It is a fragmentary sectional view showing the structure of an expansion | swelling apparatus and its periphery. It is an expanded sectional view showing composition of a main part of an expansion device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Gas cooler 3 Expansion apparatus 4 Evaporator 5 Accumulator 6 Internal heat exchanger 7 Main body 8 Piping 9 Temperature sensing cylinder 10 Tube 11 Accommodating part 16 High pressure passage 17 Differential pressure valve 18 Low pressure passage 21 Body 22 Introduction port 23 Derivation port 24 Power element 26 Diaphragm 28 Sensitive greenhouse 31 Valve body 32 Valve seat forming member 33 Main body 36 Valve portion 40 Valve seat portion 45 Communication hole

Claims (9)

In an expansion device that squeezes and expands the refrigerant circulating in the refrigeration cycle,
A differential pressure valve that acts in the valve opening direction as the differential pressure between the pressure on the upstream side where the refrigerant is introduced and the pressure on the downstream side where the expanded refrigerant is led out increases,
A temperature sensitive cylinder that senses the temperature of the refrigerant on the upstream side by enclosing a liquid material having a thermal expansion coefficient equal to or higher than a preset value and being attached to a pipe disposed on the upstream side;
The temperature sensing cylinder communicates via a tube, and has a temperature sensing chamber filled with the liquid material. The flexibility forms the temperature sensing chamber as the temperature of the upstream refrigerant increases. A power element that causes the differential pressure valve to act in a valve closing direction via a sex member;
An inflating device comprising:   The flexible member is formed of a diaphragm that seals an end opening of the power element, and transmits a force in a valve opening direction due to expansion of the temperature sensitive chamber by contacting the valve body of the differential pressure valve. The expansion device according to claim 1.   The expansion device according to claim 1, wherein the liquid material is alcohol. The power element is disposed at an end, and a body having an introduction port for introducing the refrigerant from the upstream side, and a lead-out port for deriving the refrigerant on the downstream side,
A valve body supported so as to be able to advance and retreat in the body, and one end of which is joined to the flexible member;
A valve seat forming member having a valve seat portion that is disposed opposite to the valve body in the body and opens and closes a throttle flow path that connects and disconnects the valve body to communicate the introduction port and the outlet port;
The expansion device according to claim 1, further comprising: A biasing means for biasing the valve seat forming member toward the valve body;
The valve seat forming member is configured to operate in a valve opening direction against a biasing force of the biasing means when a differential pressure between the introduction port and the outlet port increases. 4. The expansion device according to 4. The valve body has a bottomed cylindrical main body in which a refrigerant passage communicating with the introduction port is formed, and a bottom portion of the main body is joined to the flexible member, while an open end of the main body A valve portion that contacts and separates from the valve seat portion is formed by the portion;
The valve seat forming member has one end face in the axial direction receiving the pressure of the high-pressure refrigerant through the refrigerant passage, and the other end face receiving the pressure of the low-pressure refrigerant through the communication hole formed in the body. Configured
The expansion device according to claim 4.   The expansion device according to claim 5, further comprising another urging unit that urges the valve body in a valve opening direction. The body is
Downstream side of the internal heat exchanger that is disposed between the external heat exchanger and the evaporator in the refrigeration cycle and performs heat exchange between the refrigerant flowing from the external heat exchanger to the evaporator and the refrigerant flowing from the accumulator to the compressor. It is integrally attached to the end, and is configured to introduce the refrigerant flowing from the external heat exchanger to the internal heat exchanger into the introduction port, and to lead out from the lead-out port to the evaporator.
The temperature sensing cylinder is
The expansion device according to claim 4, wherein the expansion device is configured to be attached to the pipe that connects the external heat exchanger and the internal heat exchanger. A compressor that compresses the refrigerant, an external heat exchanger that cools the compressed refrigerant, an expansion device that squeezes and expands the cooled refrigerant, an evaporator that evaporates the expanded refrigerant, and stores excess refrigerant in the refrigeration cycle An accumulator that separates vapor-phase refrigerant from the evaporated refrigerant and sends it to the compressor, and an internal that exchanges heat between the refrigerant that flows from the external heat exchanger to the expansion device and the refrigerant that flows from the accumulator to the compressor In refrigeration cycle with heat exchanger,
The inflator is
A body integrally attached to the downstream end of the internal heat exchanger;
A differential pressure valve provided in the body and acting in a valve opening direction as a differential pressure between an upstream pressure at which the refrigerant is introduced and a downstream pressure at which the expanded refrigerant is led out increases;
A liquid material having a thermal expansion coefficient equal to or higher than a preset value is sealed and attached to a pipe connecting the external heat exchanger and the internal heat exchanger, thereby sensing the temperature of the refrigerant on the upstream side. A warm cylinder,
The temperature sensor is provided in the body, communicates with the inside of the temperature sensing cylinder via a tube, and is filled with the liquid material therein, and the sensitivity increases as the temperature of the refrigerant on the upstream side increases. A power element that operates the differential pressure valve in a valve closing direction via a flexible member forming a greenhouse;
A refrigeration cycle comprising:

Images