JP2006199183A - Expansion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an expansion device capable of preventing breakage of piping of a high pressure part or the like with a simple structure even if an abnormal high pressure is generated. <P>SOLUTION: The flow rate of a refrigerant supplied to an evaporator is controlled by changing an on time of a valve opening control and an off time of a valve closing control with the configuration of a solenoid valve of on/off operation opening/closing a valve hole. Valve closing is performed by an energizing force of a spring 20 so that a valve element integrated with a shaft 21 receives the pressure of the refrigerant introduced from a port 12 in the valve opening direction. When the pressure of the upstream side becomes abnormally high in closing the valve, the abnormal high pressure overcomes the energizing force of the spring 20 to burst open the valve element. Since the pressure of the upstream side is released and reduced at the downstream thereby, the breakage of the piping or the like due to the abnormal high-pressure can be prevented. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an expansion device, and more particularly to an on / off control type expansion device used in a refrigeration cycle of an automotive air conditioner system.

  In a refrigeration cycle of an automotive air conditioner system, a high-temperature and high-pressure refrigerant compressed by an engine-driven compressor is condensed or cooled by a condenser or a gas cooler, and is adiabatically expanded by an expansion device to be a low-temperature and low-pressure refrigerant. Is evaporated by an evaporator, and the evaporated refrigerant is returned to the compressor again. In general, a temperature type expansion valve is used as such an expansion device.

  The temperature type expansion valve has a valve element so that the power element senses the temperature and pressure of the outlet refrigerant of the evaporator, and the evaporation state of the refrigerant at the evaporator outlet due to the sensed refrigerant temperature and pressure becomes a predetermined degree of superheat. Controls the flow rate of the refrigerant supplied to the evaporator.

Moreover, what implement | achieved the function similar to this temperature type expansion valve with the electromagnetic type expansion apparatus is also known (for example, refer patent document 1). According to this expansion device, the pressure sensing member that detects the pressure of the refrigerant is provided on the downstream side (evaporator) side of the valve portion, and the temperature sensing element provided at the outlet of the evaporator electrically detects the temperature of the refrigerant to By controlling, the flow rate of the refrigerant supplied to the evaporator is controlled so that the refrigerant state at the evaporator outlet becomes a predetermined degree of superheat according to the temperature and pressure of the outlet refrigerant of the evaporator.
Japanese Patent Laying-Open No. 2003-4341 (FIG. 2)

  However, such an expansion device has a problem that it is expensive due to its complicated structure. Also, in a refrigeration cycle using, for example, carbon dioxide, which has a very high operating pressure as a refrigerant, the compressor control circuit on the upstream side, a pressure sensor that detects the refrigerant pressure, etc. malfunctions, causing the compressor to malfunction, thereby causing an expansion device When the high pressure part upstream of the pipe becomes abnormally high, there is a possibility that the condenser, the gas cooler, the piping of the high pressure part or the like may be broken.

  The present invention has been made in view of such points, and an object thereof is to provide an expansion device that has a simple structure and can prevent breakage of piping of a high-pressure section even when abnormally high pressure occurs. To do.

  In the present invention, in order to solve the above-described problem, in the expansion device that controls the flow rate of the refrigerant that is supplied to the evaporator by the low-temperature and low-pressure by adiabatic expansion while adiabatic expansion of the high-temperature and high-pressure refrigerant, A valve portion having a valve body for opening and closing the valve hole, and a solenoid having a spring for urging the valve body to a valve closing position when the valve is closed, and the valve body is located upstream of the valve hole when the valve is closed. An expansion device is provided in which the valve is forcibly opened against the biasing force of the spring when the difference between the pressure and the downstream pressure exceeds a predetermined value.

  According to such an expansion device, the operation in the valve closing direction by the on or off operation of the solenoid is performed by the biasing force of the spring, and the difference between the pressure on the upstream side and the pressure on the downstream side of the valve hole has a predetermined value. When the pressure exceeds, the valve body is pushed open against the biasing force of the spring, and the high pressure on the upstream side is relieved to the downstream side to reduce the pressure. As a result, even when the expansion device is in a closed state, even if the upstream side becomes abnormally high pressure, it is automatically relieved to the downstream side, so that the piping or the like is prevented from being destroyed by the abnormal high pressure. Can do.

  The expansion device of the present invention performs the valve closing operation of the valve body by the on / off operation of the solenoid only by the spring, and when the valve closing state is maintained due to the intentional control of the control circuit or the failure of the control circuit, When the pressure on the side becomes abnormally high, the spring deflects the spring and automatically opens the valve body to open the valve. For example, even if the valve becomes uncontrollable due to a failure and remains closed, With respect to the abnormal high pressure on the side, the pressure can be reduced by reducing the pressure to the downstream side, so that there is an advantage that the high pressure component can be prevented from being destroyed due to an explosion due to the abnormal high pressure.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, taking as an example a case where the present invention is applied to an expansion device used in a refrigeration cycle of an automotive air conditioner system using carbon dioxide as a refrigerant. In the figure, thick solid arrows indicate the flow direction of the refrigerant.

FIG. 1 is a diagram showing a configuration of a refrigeration cycle of an automotive air conditioner system.
A refrigeration cycle using carbon dioxide as a refrigerant includes a compressor 1 that compresses the circulating refrigerant, a gas cooler 2 that cools the high-temperature and high-pressure refrigerant compressed by the compressor 1, and an expansion device that adiabatically expands the cooled refrigerant. 3, an evaporator 4 that evaporates the expanded low-temperature / low-pressure refrigerant, an accumulator 5 that stores excess refrigerant on the outlet side of the evaporator 4 for gas-liquid separation, and a refrigerant and accumulator 5 that exits the gas cooler 2. It is comprised by the internal heat exchanger 6 which performs heat exchange between the refrigerant | coolants which came out from. In this embodiment, the expansion device 3 is attached to the internal heat exchanger 6 and controls the flow rate of the refrigerant that is adiabatically expanded and supplied to the evaporator 4 by an electric current supplied from the outside.

  In principle, the operation of the refrigeration cycle using carbon dioxide as the refrigerant operates in substantially the same manner as the refrigeration cycle using alternative chlorofluorocarbon. In other words, the compressor 1 sucks and compresses the gas-phase refrigerant separated by the accumulator 5 and discharges it as a high-temperature / high-pressure gas-phase or supercritical refrigerant. The refrigerant discharged from the compressor 1 is cooled by the gas cooler 2 and sent to the expansion device 3 via the internal heat exchanger 6. In the expansion device 3, the introduced high-temperature / high-pressure supercritical or liquid-phase refrigerant is adiabatically expanded into a low-temperature / low-pressure gas-liquid two-phase state, and is sent to the evaporator 4. In the evaporator 4, the gas-liquid two-phase refrigerant is evaporated by the air in the passenger compartment. When the gas-liquid two-phase refrigerant evaporates, the latent heat of vaporization is taken from the air in the passenger compartment to cool the air in the passenger compartment. The refrigerant evaporated by the evaporator 4 is sent to the accumulator 5, where it is temporarily stored. Of the refrigerant stored in the accumulator 5, the gas-phase refrigerant is returned to the compressor 1 via the internal heat exchanger 6. The internal heat exchanger 6 further cools the high-temperature refrigerant cooled in the gas cooler 2 by the low-temperature refrigerant sent from the accumulator 5 to the compressor 1, or cools the low-temperature refrigerant sent from the accumulator 5 to the compressor 1 from the gas cooler 2. Further heating is performed by the high-temperature refrigerant that has come out.

FIG. 2 is a central longitudinal sectional view showing the configuration of the expansion device according to the first embodiment.
The expansion device 3 has a valve body 11 at the top of the figure. A port 12 for introducing the high-pressure refrigerant that has exited the internal heat exchanger 6 is provided at the upper center of the body 11, and a port 13 for supplying a flow-controlled refrigerant to the evaporator 4 is formed at the side. ing. In the port 12, a passage that communicates with this and forms a valve hole of the valve portion and a space having an inner diameter larger than the valve hole are formed on the same axis, and the space communicates with the port 13. Opened at the bottom of the figure.

  A solenoid is provided at the lower end of the body 11. This solenoid has a sleeve 15 having a flange portion 14 which is processed in a radially outward direction by processing an upper end portion thereof, and a bottomed sleeve 16, and these opposed ends are hermetically coupled to each other by welding. ing. The lower end portion of the body 11 is fitted into the upper end portion of the sleeve 15. Further, a gasket 17 is disposed on the flange portion 14 of the sleeve 15. The gasket 17 seals the high pressure in the refrigeration cycle and the atmosphere. In this example, the gasket 17 is formed by a ring-shaped thin leaf spring, has a single corrugated portion in the circumferential direction, and has both sides. It is coated with rubber.

  A fixed iron core 18 is fitted into the bottomed sleeve 16, and a movable iron core 19 is disposed between the fixed iron core 18 and the body 11 of the valve portion so as to be movable back and forth in the axial direction. A spring 20 is disposed between the core 18 and the movable iron core 19. A shaft 21 extending through the movable iron core 19 in the axial direction is fixed to the movable iron core 19. The shaft 21 is arranged on the same axis as the valve hole, and the upper end of the figure constitutes a valve body that opens and closes the valve hole of the valve part, and the lower end of the figure is movable in the axial direction by the fixed iron core 18. It is supported.

  A coil assembly that generates magnetism is loosely fitted on the outer periphery of the sleeve 15 and the bottomed sleeve 16 so as to be rotatable about the axis of the sleeve 15 and the bottomed sleeve 16. The coil assembly includes a coil 22, a yoke 23 surrounding the coil 22, and a plate 24 for forming a magnetic closed circuit together with the yoke 23, and a power supply harness 25 connected to the coil 22 is provided. Output to the outside.

  The yoke 23 has a cup-like shape in which the upper end portion in the drawing extends inward in the radial direction and has a hole in the center, and the inward extending portion is a flange of the fixed iron core 18. It is in contact with the portion 14. Further, the yoke 23 has a threaded portion 26 threaded on the outer peripheral surface on the lower side in the drawing, and the outer periphery of the lower end portion in the drawing with respect to the threaded portion 26 is formed in a hexagonal shape.

  Although not shown, a bearing is provided in the space of the body 11 and in the fixed iron core 18 or the bottomed sleeve 16 so that the shaft 21 can move forward and backward along the axis of the valve hole. It is good to comprise so that the shaft 21 may be positioned on the same axis line as the axis line of a valve hole.

  In the expansion device 3 configured as described above, when the solenoid is not energized and the solenoid is not energized, the movable iron core 19 is urged away from the fixed iron core 18 by the spring 20 as shown in the figure. The shaft 21 fixed to the iron core 19 is urged upward in the drawing, and the valve body at the tip closes the valve hole. Accordingly, the expansion device 3 constitutes a normally closed type on / off solenoid valve that maintains a closed state when the power is not supplied.

  Next, when the solenoid is energized and the solenoid is turned on, the movable iron core 19 is attracted to the fixed iron core 18 against the biasing force of the spring 20, so that the shaft 21 moves downward in the figure, Open the valve. As a result, the high-temperature and high-pressure refrigerant introduced from the port 12 is adiabatically expanded when passing through the opened valve portion, becomes a low-temperature and low-pressure refrigerant, and is sent from the port 13 to the evaporator 4. Become.

  The expansion device 3 controls the flow rate of the flowing refrigerant by controlling the solenoid on and off. For example, the expansion device 3 is driven by a pulse current of PWM (pulse width modulation) control, and controls the refrigerant flow rate by adjusting the length of the ON time.

  Here, the control circuit of the expansion device 3, the control circuit of the compressor 1 on the upstream side, the pressure sensor for detecting the refrigerant pressure, etc. fail, and the expansion device 3 remains in the solenoid-off state, and the compressor 1 is variable. A case will be described in which the capacity control cannot be performed and the high-pressure section on the upstream side of the expansion device 3 becomes an abnormally high pressure while remaining in the maximum capacity operation state.

  The valve portion of the expansion device 3 has a structure in which a valve body integral with the shaft 21 is arranged on the downstream side of the valve hole. In the valve closed state, the valve body at one end of the shaft 21 is introduced. The refrigerant pressure is received in the valve opening direction, and the other end receives a pressure substantially equal to the pressure of the port 13 and the urging force of the spring 20 in the valve closing direction. In this state, when the pressure on the upstream side of the expansion device 3 increases and the pressure difference with the pressure on the downstream side exceeds a predetermined value determined by the load of the spring 20, the shaft 21 is moved in the valve opening direction. Since the pushing force is won, the shaft 21 bends the spring 20 and moves in the valve opening direction, and as a result, the expansion device 3 opens.

  That is, when the pressure on the upstream side of the expansion device 3 becomes an abnormally high pressure, the shaft 21 senses that and opens the valve, thereby relieving the high pressure to the downstream side. As a result, the pressure on the upstream side decreases, and it is possible to prevent damage to piping and the like due to abnormally high pressure.

FIG. 3 is a view showing a state in which the expansion device is attached to the internal heat exchanger.
In the refrigeration cycle of an automotive air conditioner system using carbon dioxide as a refrigerant, only the evaporator 4 is installed in the vehicle compartment, and the other components are installed in the engine room. In this configuration example, the expansion device 3 is attached to the internal heat exchanger 6 in the engine room so that the flow noise generated from the expansion device 3 due to the flow of the high-pressure refrigerant is not transmitted to the vehicle interior. Is to be retained.

  The internal heat exchanger 6 has two tubes 31 and 32 having different diameters, and these tubes are arranged concentrically by blocks 33 (only one side is shown in the figure) provided on both sides. The inner tube 31 constitutes a passage through which high-temperature / high-pressure refrigerant from the gas cooler 2 flows, and the outer tube 32 is an annular passage through which the low-temperature / low-pressure refrigerant from the accumulator 5 flows between the inner tube 31. Is configured. The inner tube 31 is also made of a material having good thermal conductivity, and heat exchange is performed between a high-temperature / high-pressure refrigerant flowing inside and a low-temperature / low-pressure refrigerant flowing outside.

  The block 33 of the internal heat exchanger 6 includes a port 34 through which the inner tube 31 is brazed to introduce a high-temperature / high-pressure refrigerant, and a port through which the refrigerant adiabatically expanded by the expansion device 3 to obtain a low-temperature / low-pressure refrigerant. 35, a port 36 for introducing the refrigerant from the accumulator 5, a port 37 for guiding the refrigerant introduced to the port 36 by brazing the outer tube 32 to the passage between the tubes 31, 32, and the expansion device 3 And a mounting hole 38 for attaching the. A threaded portion 39 is engraved inside the mounting hole 38 in the vicinity of the opening end.

  When such an expansion device 3 is attached to the block 33 of the internal heat exchanger 6, the expansion device 3 is inserted into the mounting hole 38 of the block 33 and the coil assembly of the expansion device 3 is turned to attach the screw portion 26 to the mounting hole 38. Then, the coil assembly is screwed using a tool such as a spanner. At this time, the gasket 17 and the sleeve 15 are pressed against the stepped portion inside the mounting hole 38 without being rotated by the frictional force of the gasket 17. At that time, the corrugated portion of the gasket 17 is crushed to bring the flange portion 14 into close contact with the block 33, and the valve portion of the expansion device 3 is sealed from the atmosphere.

  FIG. 4 is a central longitudinal sectional view showing the configuration of the expansion device according to the second embodiment. In FIG. 4, the same or equivalent components as those shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted.

  The expansion device 41 according to the second embodiment constitutes a normally closed type on / off solenoid valve, whereas the expansion device 3 according to the first embodiment is a normal open type. It is different in point. For this reason, the expansion device 41 reverses the positions of the fixed iron core 18 and the movable iron core 19 of the solenoid and opens the valve with a larger spring load than the spring 20 between the fixed iron core 18 and the movable iron core 19. A spring 42 is provided. The shaft 21 is loosely fitted through the fixed iron core 18 and the movable iron core 19 in the axial direction, and a stopper 43 is fixed to the end opposite to the side constituting the valve body. . The stopper 43 has an outer diameter larger than the inner diameter of the through hole of the movable iron core 19 into which the shaft 21 is loosely fitted, and is attached in a direction in which the movable iron core 19 is separated from the fixed iron core 18 by the spring 42. When energized, the movable iron core 19 is engaged with a stopper 43 energized in the valve closing direction by the spring 20 so that the shaft 21 can be held in the valve open position.

  Further, when the solenoid is energized, the moving iron core 19 moves from the valve opening position until it is attracted to the fixed iron core 18, and the valve element moves from the valve opening position to the valve closing position for closing the valve hole. It is set larger than the stroke. For this reason, in the process in which the solenoid is energized and the movable iron core 19 is attracted to the fixed iron core 18 against the biasing force of the spring 42 for opening the valve, at first, as the movable iron core 19 moves, The stopper 43 urged in the valve closing direction by the spring 20 moves together in the valve closing direction. On the way, the tip of the shaft 21 comes into contact with the opening end of the valve hole. Then, it is separated from the stopper 43 and is attracted to the fixed iron core 18. For this reason, the shaft 21 is maintained in the valve closing position by the urging force of the spring 20.

  The operation of the expansion device 41 is reverse between the expansion device 3 according to the first embodiment and the opening / closing operation of the valve portion when the solenoid is not energized and when the solenoid is energized. However, if the differential pressure between the pressure on the upstream side and the pressure on the downstream side of the valve section exceeds the specified value when the valve is closed during energization, the valve body is pushed open and abnormal upstream pressure on the upstream side is reduced. It is the same in that it operates to relieve to the side.

  FIG. 5 is a central longitudinal sectional view showing the configuration of the expansion device according to the third embodiment. 5, the same or equivalent components as those shown in FIG. 4 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Compared with the expansion device 41 according to the second embodiment, the expansion device 51 according to the third embodiment is a load of the spring 20 that urges the valve 20 in the valve closing direction against the pressure of the introduced refrigerant. The difference is that the pressure at which the refrigerant can be relieved can be set higher without increasing the value.

  For this reason, the expansion device 51 according to the third embodiment has a cylindrical shaft 52, which is configured to hold the fixed iron core 18 so as to advance and retract in the axial direction. The cylindrical shaft 52 has an outer diameter smaller than the inner diameter of the valve hole, and a valve body 53 having an outer diameter larger than the inner diameter of the valve hole is integrally formed at an end facing the valve hole.

  Thereby, in this expansion device 51, when the solenoid is in a closed state when energized, the refrigerant pressure introduced from the port 12 passes through the center of the cylindrical shaft 52 and the movable iron core 19 is accommodated. It is adapted to be introduced into the bottom sleeve 16. Therefore, the valve body 53 receives the refrigerant pressure introduced from the port 12 in the valve opening direction with a pressure receiving area obtained by subtracting the cross-sectional area of the central hole of the cylindrical shaft 52 from the cross-sectional area of the valve hole. 52, the refrigerant pressure introduced from the port 12 is received in the valve closing direction at a pressure receiving area obtained by subtracting the cross-sectional area of the center hole from the cross-sectional area of the outer diameter at the lower end surface of the figure. Since the outer diameter of the cylindrical shaft 52 is smaller than the inner diameter of the valve hole, the pressure receiving area for receiving the refrigerant pressure introduced from the port 12 in the valve opening direction is larger than the pressure receiving area for receiving in the valve closing direction. Due to the difference, a force that pushes the valve body 53 and the cylindrical shaft 52 downward in the figure, that is, a force in the valve opening direction, is generated by the refrigerant pressure introduced from the port 12. With this configuration, the expansion device 51 can set the pressure receiving area acting in the valve opening direction to be small, so that the set pressure at the time of valve opening due to abnormally high pressure can be set high.

  FIG. 6 is a central longitudinal sectional view showing the configuration of the expansion device according to the fourth embodiment. In FIG. 6, the same or equivalent components as those shown in FIG. 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  Compared with the expansion device 51 according to the third embodiment, the expansion device 61 according to the fourth embodiment introduces the refrigerant to the side where the valve body is located and reverses the flow direction of the refrigerant through the valve portion. It is different in point that we made. For this reason, the expansion device 61 has a port 12 for introducing the refrigerant to the side portion of the body 11 and a port 13 for leading the expanded refrigerant to the front end surface of the body 11. The cylindrical shaft 52 has an outer diameter larger than the inner diameter of the valve hole, and a difference in pressure receiving area generated thereby causes the cylindrical shaft 52 to act in the valve opening direction. Accordingly, in this expansion device 61 as well, as in the expansion device 51, the pressure receiving area acting in the valve opening direction can be reduced, so that the set pressure at the time of valve opening due to abnormally high pressure can be set high.

  FIG. 7 is a view showing a state in which the expansion device according to the fourth embodiment is attached to the internal heat exchanger. In FIG. 7, the same or equivalent components as those shown in FIG. 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the block 33 of the internal heat exchanger 6 to which the expansion device 61 according to the fourth embodiment is attached, the port 34 to which the inner high pressure tube 31 is connected is on the body 11 side of the expansion device 61. A port 35 for connecting a pipe to the evaporator 4 is communicated with a port 13 provided at the tip of the body 11.

  The attachment of the expansion device 61 to the block 33 is also performed in the same manner as the attachment method shown in FIG. 3 by inserting the expansion device 61 into the mounting hole 38 of the block 33 and turning the coil assembly. 26 is screwed into the threaded portion 39 of the mounting hole 38.

It is a figure which shows the structure of the refrigerating cycle of the air-conditioner system for motor vehicles. It is a center longitudinal cross-sectional view which shows the structure of the expansion apparatus which concerns on 1st Embodiment. It is a figure which shows the attachment state of the expansion apparatus to an internal heat exchanger. It is a center longitudinal cross-sectional view which shows the structure of the expansion apparatus which concerns on 2nd Embodiment. It is a center longitudinal cross-sectional view which shows the structure of the expansion apparatus which concerns on 3rd Embodiment. It is a center longitudinal cross-sectional view which shows the structure of the expansion apparatus which concerns on 4th Embodiment. It is a figure which shows the attachment state to the internal heat exchanger of the expansion apparatus which concerns on 4th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Gas cooler 3 Expansion apparatus 4 Evaporator 5 Accumulator 6 Internal heat exchanger 11 Body 12, 13 Port 14 Flange part 15 Sleeve 16 Bottomed sleeve 17 Gasket 18 Fixed iron core 19 Movable iron core 20 Spring 21 Shaft 22 Coil 23 Yoke 24 Plate 25 Harness 26 Screw portion 31, 32 Tube 33 Block 34, 35, 36, 37 Port 38 Mounting hole 39 Screw portion 41 Expansion device 42 Spring 43 Stopper 51 Expansion device 52 Cylindrical shaft 53 Valve body 61 Expansion device

Claims (8)

In an expansion device that controls the flow rate of refrigerant supplied to the evaporator by adiabatic expansion and low-temperature / low-pressure while adiabatic expansion of high-temperature / high-pressure refrigerant,
A valve portion having a valve body for opening and closing the valve hole, and a solenoid having a spring for biasing the valve body to a valve closing position when the valve is closed,
The valve body is forcibly opened against the urging force of the spring when the difference between the pressure on the upstream side and the pressure on the downstream side of the valve hole exceeds a predetermined value when the valve is closed. Inflating device characterized. The valve portion is arranged on the downstream side of the valve hole so as to receive the pressure of the introduced refrigerant in the valve opening direction,
The solenoid has a movable iron core, a spring, and a fixed iron core arranged in this order on the same axis line as the valve hole from the valve portion side, and is fixed to the movable iron core in the axial direction and has one end at the end. The shaft that constitutes the valve body that opens and closes the valve hole, the other end of which is held by the fixed iron core so as to be movable forward and backward in the axial direction, and is fixed to the movable iron core by the spring when not energized The valve body integral with the valve is held in the closed position, and when energized, the movable iron core is attracted to the fixed iron core against the urging force of the spring, so that the valve body is brought into the valve open position. The expansion device according to claim 1, wherein the expansion device is held. The valve portion is arranged on the downstream side of the valve hole so as to receive the pressure of the introduced refrigerant in the valve opening direction,
In the solenoid, a fixed iron core, a valve opening spring, a movable iron core, a stopper, and the spring are arranged in this order on the same axis as the valve hole from the valve portion side, and the fixed iron core and the movable iron It has a shaft that is loosely fitted through the core in the axial direction, one end forms the valve body that opens and closes the valve hole, and the other end has a shaft fixed to the stopper, and is attached in the valve opening direction when not energized. The valve body is held in the valve open position by the spring for opening the valve and the spring biased in the valve closing direction, and the valve body is held in the valve closed position by the spring when energized. The expansion device according to claim 1.   The solenoid moves a stroke in which the movable iron core moves from the valve opening position of the valve body to the fixed iron core when energized, and the valve body moves from the valve opening position to the valve closing position when energized. 4. The expansion device according to claim 3, wherein the expansion device is set to be larger than the moving stroke. The valve portion is arranged on the downstream side of the valve hole so that the pressure of the introduced refrigerant is received in the valve opening direction.
In the solenoid, a fixed iron core, a valve opening spring, a movable iron core, a stopper, and the spring are arranged in this order on the same axis line as the valve hole from the valve portion side, and the fixed iron core is arranged in the axial direction. The valve body that is held through and movable freely and penetrates the movable iron core in the axial direction and has one end constituting the valve body that opens and closes the valve hole, and the other end is fixed to the stopper, It has a cylindrical shaft having an outer diameter smaller than the inner diameter of the valve hole, and the valve element is opened by the valve-opening spring that biases in the valve-opening direction and the spring that biases in the valve-closing direction when not energized. 2. The expansion device according to claim 1, wherein the valve body is held at a valve position and the valve body is held at a valve closing position by the spring when energized.   The solenoid moves a stroke in which the movable iron core moves from the valve opening position of the valve body to the fixed iron core when energized, and the valve body moves from the valve opening position to the valve closing position when energized. 6. The expansion device according to claim 5, wherein the expansion device is set larger than the moving stroke. In the valve portion, the valve body is disposed on the upstream side of the valve hole,
In the solenoid, a fixed iron core, a valve opening spring, a movable iron core, a stopper, and the spring are arranged in this order on the same axis line as the valve hole from the valve portion side, and the fixed iron core is arranged in the axial direction. The valve body that is held through and movable freely and penetrates the movable iron core in the axial direction and has one end constituting the valve body that opens and closes the valve hole, and the other end is fixed to the stopper, It has a cylindrical shaft having an outer diameter larger than the inner diameter of the valve hole, and opens the valve body by the valve-opening spring that biases in the valve-opening direction when not energized and the spring that biases in the valve-closing direction. 2. The expansion device according to claim 1, wherein the valve body is held in a valve position and the valve body is held in a valve closing position by the spring when energized. The solenoid moves a stroke in which the movable iron core moves from the valve opening position of the valve body to the fixed iron core when energized, and the valve body moves from the valve opening position to the valve closing position when energized. 8. The expansion device according to claim 7, wherein the expansion device is set larger than the moving stroke.

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