JP2008281280A - Expansion valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the temperature of a high-pressure refrigerant from being transmitted to a power element via a body in an expansion valve where a port for connecting a high-pressure piping is disposed in proximity to the power element. <P>SOLUTION: A gap part 23 is formed between a body 10 and a power element 20, and a refrigerant whose temperature the power element 20 senses is allowed to flow in the gap part 23. Since the body 10 and the power element 20 are spaced apart from each other and the refrigerant is made to flow in the gap part 23 to prevent heat transfer via the stagnant refrigerant, this arrangement keeps the temperature of the high-pressure refrigerant introduced in an inlet port 11 from being transmitted to the power element 20 via the body 10. Thus, the power element 20 can precisely sense the temperature of the refrigerant at the outlet of an evaporator and the flow rate of the refrigerant supplied to the evaporator can be controlled to a proper flow rate. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an expansion valve, and more particularly to an expansion valve that controls the flow rate of refrigerant sent to an evaporator in accordance with the temperature and pressure of the refrigerant at the outlet of the evaporator in a refrigeration cycle of an automotive air conditioner.

  An automotive air conditioner generally includes a compressor driven by a vehicle engine, a condenser that condenses the refrigerant compressed by the compressor, a receiver that separates the condensed refrigerant into gas and liquid, and stores liquid refrigerant. An expansion valve that squeezes and expands the high-temperature and high-pressure liquid refrigerant to form a low-temperature and low-pressure mist refrigerant, and an evaporator that evaporates the mist refrigerant by exchanging heat with the air in the passenger compartment and returns it to the compressor. I have.

  As such an expansion valve, a temperature-type expansion valve is known in which the flow rate of the refrigerant sent to the evaporator is controlled so that the refrigerant that has exited the evaporator has a predetermined degree of superheat (for example, Patent Document 1). reference.). The expansion valve described in Patent Document 1 is a valve portion that squeezes and expands a high-temperature / high-pressure liquid refrigerant to form a low-temperature / low-pressure mist refrigerant, and detects the temperature and pressure of the refrigerant that has exited the evaporator. And a power element for controlling the valve lift of the part. In the power element, the temperature sensing cylinder is tied to the outlet piping of the evaporator, the temperature sensing cylinder senses the refrigerant temperature at the evaporator outlet, and the change in pressure due to the temperature change is partitioned by a diaphragm through the capillary tube. I try to communicate to the room. Further, the power element indirectly senses the pressure of the refrigerant that has exited the evaporator by sensing the pressure of the refrigerant immediately after expansion of the diaphragm. This is based on the fact that the pressure loss due to the refrigerant passing through the evaporator is substantially constant, so that the pressure of the refrigerant exiting the evaporator can be estimated by the pressure of the refrigerant entering the evaporator. The control of the valve lift is to transmit the displacement of the diaphragm due to the change of the pressure of the room partitioned by the diaphragm to the valve unit according to the temperature and pressure of the refrigerant at the evaporator outlet detected as described above. Is going on.

  This type of expansion valve has a simple configuration including a valve portion having two ports to which a high pressure pipe and a low pressure pipe to an evaporator are connected, and a power element to which a temperature sensing cylinder is connected. Since the temperature sensing tube provided at the tip must be attached to the outlet piping of the evaporator, the assembly to the vehicle is complicated. Therefore, if the power element attached to the body of the valve portion can directly sense the temperature of the refrigerant that has exited the evaporator, it is possible to reduce the complexity during assembly.

  On the other hand, a block-type expansion valve is known in which the power element directly senses the temperature of the refrigerant that has exited the evaporator (see, for example, Patent Document 2). This expansion valve is formed by a block having a prism-shaped body, and the block has a high-pressure pipe to which a high-temperature / high-pressure refrigerant is supplied, a low-pressure pipe for sending the expanded refrigerant to the evaporator inlet, Evaporated refrigerant is fed from the outlet of the evaporator, and further has four ports to which two low-pressure return pipes that are returned to the inlet of the compressor are connected, and functions as a pipe joint. The power element coupled to one end in the longitudinal direction of the body communicates internally with a low-pressure return passage formed between ports adjacent to the two to which two low-pressure return pipes are connected. It is configured to directly sense the temperature and pressure of the refrigerant flowing through the. The port connecting the high-pressure piping and the low-pressure piping to the evaporator is provided on the opposite side of the power element mounting side across the low-pressure return passage, so that the high temperature of the high pressure refrigerant and the low temperature of the low pressure refrigerant are powered via the body. The structure is difficult to transfer heat to the element.

By the way, since the body structure is simple even for an expansion valve having a valve portion having two ports for high pressure piping and low pressure piping in the body and a power element fixed to the body, the power element There is a demand for an expansion valve that can directly and accurately sense the temperature and pressure of the refrigerant exiting the evaporator.
Japanese Patent Laid-Open No. 10-259968 JP 2001-336862 A

  However, an expansion valve equipped with a valve element having two ports in the body and a power element has a temperature-sensitive error because the high temperature of the high-pressure refrigerant and the low temperature of the low-pressure refrigerant easily transfer to the power element through the body. There was a problem that it was difficult to control the flow rate appropriately.

  The present invention has been made in view of the above points, and an expansion valve that suppresses the temperature of the refrigerant flowing through the valve portion from being transmitted to the power element through the body so as not to cause a temperature-sensitive error. The purpose is to provide.

  In the present invention, in order to solve the above problem, a power element that senses the temperature and pressure of the refrigerant that has exited the evaporator, and a valve that controls the flow rate of the refrigerant that is sent to the evaporator according to the temperature and pressure sensed by the power element. In the expansion valve provided with a portion, there is a gap portion between the mounting end surface of the body of the valve portion to which the power element is mounted and the surface of the housing facing the mounting end surface of the power element. An expansion valve is provided.

  According to such an expansion valve, the gap formed between the body and the power element can substantially block the heat transfer path from the body to the power element. Thus, the temperature of the high-temperature refrigerant introduced into the valve portion and the low-temperature refrigerant derived from the valve portion is blocked by the gap portion and does not transfer heat to the power element. Therefore, it is possible to correctly detect the temperature of the refrigerant and supply an appropriate flow rate of refrigerant to the evaporator.

  The expansion valve according to the present invention is configured to prevent heat transfer from the body to the power element by providing a gap between the body and the power element, so that the power element correctly senses the temperature of the refrigerant from the evaporator. Thus, the flow rate of the refrigerant supplied to the evaporator can be controlled to an appropriate flow rate.

  In addition, since this expansion valve uses the gap portion as a refrigerant passage, a refrigerant flow can be generated there, so heat transfer from the refrigerant to the power element is improved, and the degree of superheat is correctly detected. Thus, the refrigerant flow rate can be controlled appropriately. By enabling this appropriate flow rate control, air with a stable blowing temperature can be supplied into the passenger compartment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
1 is a diagram showing an overview of an expansion valve according to the first embodiment, FIG. 2 is a sectional view taken along the line aa in FIG. 1, and FIG. 3 is a sectional view taken along the line bb in FIG.

  The expansion valve according to the first embodiment has a body 10, an inlet port 11 for introducing a high-pressure refrigerant is laterally provided at one end (upper end in the figure) in the longitudinal direction, and the axial position of the other end Is formed with an outlet port 12 for leading out low-pressure refrigerant. The body 10 has a valve hole 13 in which the inlet port 11 and the outlet port 12 communicate with each other, and a valve body 14 for opening and closing the valve hole 13 is attached to the valve closing direction by a spring 15 on the low pressure side. It is arranged in a state of being urged. The spring 15 is received by an adjusting member 16 that is press-fitted into the outlet port 12 of the body 10, and the load is adjusted by the amount of press-fitting of the adjusting member 16 into the body 10, so that the set value of the expansion valve is adjusted. Has been.

  The valve body 14 is formed integrally with a shaft 17 supported by the body 10 so as to be able to advance and retract in the opening and closing direction. The shaft 17 has a diameter-reduced portion located in the upstream space of the valve hole 13 communicating with the inlet port 11, and forms a refrigerant flow path for supplying liquid refrigerant to the valve hole 13 around the shaft 17. . In addition, the upper end portion of the shaft 17 is reduced in diameter by two steps from the portion supported by the body 10 of the shaft 17, and the reduced diameter portion on the lower side of the drawing has a high pressure introduced into the inlet port 11. An O-ring 18 is provided around the refrigerant so that the refrigerant does not leak outside through the clearance between the body 10 and the shaft 17. A ring-shaped collar member 19 is fixed to the reduced diameter portion at the tip of the shaft 17 by press fitting, and the outer diameter of the collar member 19 is substantially equal to the inner diameter of the valve hole 13. As a result, the high pressure introduced into the inlet port 11 is canceled approximately equally in the direction in which the valve body 14 is opened and the direction in which the collar member 19 is closed. As a result, the introduced high pressure varies. However, the flow rate control is not affected by high pressure fluctuations.

  The upper end of the body 10 in the figure is a mounting end surface to which the power element 20 is mounted. A cylindrical portion 21 and a stopper 22 project from the mounting end surface. The cylindrical portion 21 is disposed coaxially with the valve hole 13 and is formed integrally with the body 10, and a screw is threaded on the outer periphery thereof. The stopper 22 is abutted when the power element 20 is screwed to the cylindrical portion 21 and is attached to the body 10 at a predetermined distance from the attachment end surface of the body 10. 20 to form a gap 23. As shown in FIG. 3, for example, a coolant passage 23 a for allowing the coolant to flow in a direction parallel to the axis of the inlet port 11 is formed in the gap portion 23 between the stopper 22 and the cylindrical portion 21. It has a chip shape.

  The power element 20 includes a thick metal upper housing 24 and a lower housing 25, a diaphragm 26 made of a flexible thin metal plate arranged so as to partition a space surrounded by these, and a center disk 27. Yes. The outer periphery of the upper housing 24, the diaphragm 26, and the lower housing 25 are joined by welding, and the space surrounded by the upper housing 24 and the diaphragm 26 constitutes a temperature-sensitive room where refrigerant gas or the like is contained. Filled. The center disk 27 has an upper surface in contact with the lower surface of the diaphragm 26, and a lower surface in contact with the end surface of the collar member 19, so that the displacement of the diaphragm 26 is transmitted to the valve body 14. The central opening of the lower housing 25 has a cylindrical shape extending in the direction of the diaphragm 26, and the inner wall surface of the lower housing 25 is threadedly engaged with the cylindrical portion 21 protruding from the mounting end surface of the body 10. The screw is threaded. The lower housing 25 is also provided with a vent hole 28 so that the refrigerant around the power element 20 is introduced into the space on the lower surface side of the diaphragm 26.

  The body 10 has a protruding member 29 that protrudes in all directions from the side surface. The projecting member 29 is intended to facilitate positioning when the expansion valve is attached in the vicinity of the evaporator.

  In the expansion valve having the above configuration, first, when the automobile air conditioner is stopped, the gas enclosed in the temperature-sensitive room of the power element 20 is condensed and has a low pressure, so that it is shown in FIG. In addition, the diaphragm 26 is displaced inward (upward in the drawing), and the displacement is transmitted to the valve body 14 through the shaft 17, and the expansion valve is in a fully closed state.

  Here, when the automotive air conditioner is activated, the refrigerant is sucked by the compressor, so the pressure of the return low-pressure pipe connected to the inlet of the compressor is reduced, and this is detected by the power element 20 and the diaphragm 26 is displaced outward. The valve body 14 is lifted. On the other hand, the refrigerant compressed by the compressor is condensed by the condenser, and the liquid refrigerant separated by the receiver is supplied to the inlet port 11 of the expansion valve through the high-pressure pipe. In addition, the arrow in a figure has shown the flow direction of the refrigerant | coolant. The high-temperature and high-pressure liquid refrigerant is expanded when passing through the expansion valve, and becomes a low-temperature and low-pressure gas-liquid mixed refrigerant and exits from the outlet port 12. The refrigerant is supplied to the evaporator, evaporated inside, and comes out from the refrigerant outlet. The refrigerant returned from the evaporator passes around the power element 20 and returns to the compressor inlet. At that time, the power element 20 senses the temperature and pressure of the refrigerant passing therethrough.

  In the early stage of starting the air conditioner for automobiles, the temperature of the refrigerant returning from the evaporator is increased due to heat exchange with the hot air in the passenger compartment, and the power element 20 senses the temperature and Pressure increases. As a result, the diaphragm 26 is displaced in the valve opening direction until the center disk 27 in contact with the diaphragm 26 contacts the inner wall of the lower housing 25, and the displacement is transmitted to the valve body 14 via the shaft 17 and expanded. The valve is fully open.

  Eventually, when the temperature of the refrigerant returning from the evaporator decreases, the pressure in the sensation greenhouse decreases, and accordingly, the diaphragm 26 is displaced upward in the figure, and the expansion valve operates in the valve closing direction. Thus, the flow rate of the refrigerant passing through this is controlled. At this time, the expansion valve senses the refrigerant temperature at the evaporator outlet and controls the flow rate of the refrigerant supplied to the evaporator so that the refrigerant maintains a predetermined degree of superheat.

  By the way, in this expansion valve, the body 10 is made of metal formed by, for example, die casting, and the inlet port 11 is disposed at a position close to one end where the power element 20 is mounted. The temperature of the refrigerant introduced into the port 11 is easily transmitted to the power element 20. However, in this expansion valve, the power element 20 and the body 10 are separated from each other to form the refrigerant passage 23a, and the contact area between the power element 20 and the body 10 is brought into contact with the stopper 22 instead of the entire circumference. The thermal resistance is high because

  Therefore, the temperature of the high-temperature / high-pressure refrigerant introduced into the inlet port 11 and the temperature of the low-temperature / low-pressure refrigerant derived from the outlet port 12 are formed in the gap 23 between the power element 20 and the body 10. Since the low-temperature transmission to the power element 20 is suppressed by the refrigerant passage 23a and the stopper 22 having a small contact area, the power element 20 accurately senses the temperature of the refrigerant from the evaporator and sends it to the evaporator. The supplied refrigerant is controlled to have an appropriate flow rate. Further, since the flow of the refrigerant in the refrigerant passage 23a is promoted, heat exchange with the refrigerant returned from the evaporator is promoted, so that heat transfer from the inlet port 11 to the power element 20 is further suppressed, and the power element 20 Furthermore, correct temperature sensing can be performed. As a result, the flow rate of the refrigerant supplied to the evaporator is stabilized, and the unevenness of the blowing temperature of the air that has passed through the evaporator does not increase, so that the blowing temperature can be stabilized.

  4A and 4B are views showing an expansion valve according to the second embodiment, in which FIG. 4A is a partial cross-sectional view showing the main part, and FIG. 4, the same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve according to the second embodiment, the heat insulation effect between the power element 20 and the body 10 is further improved as compared with the expansion valve according to the first embodiment. That is, in this expansion valve, a plurality of vent holes 28 are formed between the central cylindrical portion in which the screw of the lower housing 25 is provided and the outer peripheral welded portion. These vent holes 28 have rectangular openings that are long in the radial direction, and are evenly arranged in the circumferential direction.

  In this expansion valve, the plurality of vent holes 28 are provided in the lower housing 25, so that the refrigerant does not stagnate in the lower housing 25, and heat can be transferred from the body 10 to the power element 20 through the refrigerant therein. Disappear. In addition, in this expansion valve, the flow of the refrigerant as shown by the arrow is generated in the lower housing 25, so that the temperature sensitivity by the power element 20 becomes more accurate and the response to the temperature change can be improved.

  In this embodiment, more effective heat insulation is realized by the combination of the gap portion 23 formed between the power element 20 and the body 10, but the flow of the refrigerant in the lower housing 25 is achieved. Even if it is only made, heat transfer due to stagnation of the refrigerant is eliminated, so that a sufficient heat insulating effect can be obtained.

FIG. 5 is a plan view showing a lower housing of the expansion valve according to the third embodiment.
In the expansion valve according to the third embodiment, the shape of the vent hole 28 provided in the lower housing 25 is changed. That is, the lower housing 25 is formed by pressing a disk in which a central opening and a vent hole 28 are formed. In the present embodiment, the vent hole 28 is a round hole that is easy to process. ing. Note that the number or size of these vent holes 28 is appropriately changed as necessary. Other configurations of the expansion valve are the same as those of the expansion valve according to the second embodiment.

  6A and 6B are views showing an expansion valve according to a fourth embodiment, wherein FIG. 6A is a partial cross-sectional view showing a main part, FIG. 6B is a central cross-sectional view of a center disk, and FIG. It is a bottom view. In FIG. 6, the same components as those shown in FIGS. 1 to 5 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve according to the fourth embodiment, the heat insulation effect between the power element 20 and the body 10 is further improved as compared with the expansion valves according to the first to third embodiments. That is, in this expansion valve, in order to restrict the displacement of the diaphragm 26, the center disk 27 in contact with the diaphragm 26 has a circular plate portion 30 and a cylindrical portion 31 that hangs downward from the outer peripheral edge portion of the drawing. Are formed integrally so that the tip of the cylindrical portion can come into contact with the inner wall surface of the lower housing 25. The cylindrical portion 31 is movable forward and backward in the displacement direction of the diaphragm 26 with a cylindrical portion formed in the center of the lower housing 25 as a guide, so that the contact portion between the collar member 19 and the disc portion 30 is a cylindrical portion. It is dressed in a space closed by the shape portion 31. In this expansion valve, a plurality of slits 32 are provided in the cylindrical portion 31 of the center disk 27, and as shown in FIG. 6 (A), a refrigerant flows at the contact portion between the collar member 19 and the disc portion 30. I try to let them. As a result, the temperature of the refrigerant flowing through the slit 32 is sensed by the temperature sensing portion of the power element 20 by being transmitted to the diaphragm 26 via the center disk 27, via the body 10 and its cylindrical portion 21. The heat transmitted from the inlet port 11 is not transmitted to the diaphragm 26 via the refrigerant in the cylindrical portion 31 of the center disk 27, so that the temperature sensitivity by the power element 20 becomes more accurate, and the temperature Response to changes can be further improved. Other configurations of the expansion valve are the same as those of the expansion valves according to the second and third embodiments.

  In the expansion valve according to the fourth embodiment, a plurality of slits 32 are provided in the cylindrical portion 31 in order to cause the refrigerant to flow in the center disk 27. You may make it open a hole.

  7A and 7B are views showing an expansion valve according to a fifth embodiment, wherein FIG. 7A is a partial cross-sectional view showing the main part, FIG. 7B is a plan view of the center disk, and FIG. 7C is the center of the center disk. Sectional drawing, (D) is a bottom view of the center disk. 7, the same components as those shown in FIGS. 1 to 6 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve according to the fifth embodiment, the heat insulating effect between the power element 20 and the body 10 is further improved as compared with the expansion valve according to the fourth embodiment. That is, in this expansion valve, in order to further reduce the heat transfer from the body 10 to the diaphragm 26, the contact area between the center disk 27 and the diaphragm 26 is reduced, and a refrigerant flow is generated between the center disk 27 and the diaphragm 26. I try to let them. For this reason, as shown in FIG. 7B, the center disk 27 has two grooves 33 formed on the surface of the disk portion 30 on the diaphragm 26 side. In the example shown in the figure, these grooves 33 are formed so as to intersect at right angles through the center of the disk portion 30.

  By providing the groove 33 on the surface of the disk portion 30, the area of the center disk 27 in contact with the diaphragm 26 is reduced, so that heat transfer from the center disk 27 to the diaphragm 26 is reduced, and the center disk 27 and the diaphragm 26 are not connected. Therefore, the refrigerant temperature can be detected more accurately by the power element 20.

  In the expansion valve according to the fifth embodiment, the groove 33 is formed on the surface of the center disk 27 on the side in contact with the diaphragm 26 to reduce the contact area and to cause the refrigerant to flow in the groove 33. However, heat transfer from the inlet port 11 to the diaphragm 26 is made difficult, but the heat conduction from the inlet port 11 to the diaphragm 26 is further reduced by making the center disk 27 itself a material having low thermal conductivity. be able to.

  FIG. 8 is a partial cross-sectional view showing a main part of an expansion valve according to the sixth embodiment. In FIG. 8, the same components as those shown in FIGS. 1 to 7 are denoted by the same reference numerals, and detailed description thereof is omitted.

  In the expansion valve according to the sixth embodiment, a heat insulating material 47 is disposed in the gap 23 between the power element 20 and the body 10 to suppress heat transfer from the body 10 to the diaphragm 26. The heat insulating material 47 is formed, for example, in such a shape as to be disposed in the refrigerant passage 23a of FIG. Of course, the heat insulating material 47 may be configured to also serve as the stopper 22 of the power element 20 attached to the body 10.

FIG. 9 is a cross-sectional view showing an example of attachment to an evaporator.
The evaporator 40 is configured by laminating a plurality of aluminum plates, and has an inlet pipe 41 for introducing a refrigerant and an outlet pipe 42 for leading the refrigerant to the header portion. The outlet pipe 42 is arranged coaxially so as to surround the inlet pipe 41, and a cylindrical case 43 whose one end is closed is externally mounted and is hermetically coupled by a clamp 44. An expansion valve is mounted in the case 43.

  In the case 43, the outlet port 12 of the expansion valve is fitted to the inlet pipe 41 of the evaporator 40, and the high-pressure pipe 45 inserted through the case 43 is fitted to the inlet port 11. A low-pressure return pipe 46 connected to the inlet of the compressor is connected to the side surface of the case 43 in a direction perpendicular to the paper surface.

  In the above configuration, the high-pressure liquid refrigerant sent through the high-pressure pipe 45 is introduced into the inlet port 11 of the expansion valve, and the refrigerant derived from the outlet port 12 is directly introduced into the evaporator 40 through the inlet pipe 41. . The refrigerant evaporated by the evaporator 40 is introduced into the case 43 from the outlet pipe 42, passes through the case 43, and is guided to the compressor inlet by the low-pressure return pipe 46. The refrigerant introduced from the evaporator 40 into the case 43 passes through the refrigerant passage 23 a formed between the body 10 and the power element 20 as it passes through the case 43 and is sucked into the low pressure return pipe 46. At the same time, it passes through the lower housing 25 of the power element 20 through the vent hole 28. Further, the refrigerant passing through the lower housing 25 flows in the cylindrical portion 31 of the center disk 27 through the slit 32, and flows between the center disk 27 and the diaphragm 26 through the groove 33.

It is a figure which shows the general view of the expansion valve which concerns on 1st Embodiment. FIG. 2 is a cross-sectional view taken along the line aa in FIG. 1. FIG. 3 is a cross-sectional view taken along line bb in FIG. 2. It is a figure which shows the expansion valve which concerns on 2nd Embodiment, Comprising: (A) is a fragmentary sectional view which shows the principal part, (B) is a top view of a lower housing. It is a top view which shows the lower housing of the expansion valve which concerns on 3rd Embodiment. It is a figure which shows the expansion valve which concerns on 4th Embodiment, Comprising: (A) is a fragmentary sectional view which shows the principal part, (B) is a center sectional view of a center disk, (C) is a bottom view of a center disk. is there. It is a figure which shows the expansion valve which concerns on 5th Embodiment, Comprising: (A) is a fragmentary sectional view which shows the principal part, (B) is a top view of a center disk, (C) is a center sectional view of a center disk, (D) is a bottom view of the center disk. It is a fragmentary sectional view showing an important section of an expansion valve concerning a 6th embodiment. It is sectional drawing which shows the example of mounting | wearing to an evaporator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Body 11 Inlet port 12 Outlet port 13 Valve hole 14 Valve body 15 Spring 16 Adjustment member 17 Shaft 18 O-ring 19 Collar member 20 Power element 21 Cylindrical part 22 Stopper 23 Gap part 23a Refrigerant passage 24 Upper housing 25 Lower housing 26 Diaphragm 27 Center disk 28 Ventilation hole 29 Protruding member 30 Disk part 31 Cylindrical part 32 Slit 33 Groove 40 Evaporator 41 Inlet pipe 42 Outlet pipe 43 Case 44 Clamp 45 High pressure pipe 46 Low pressure return pipe 47 Thermal insulation

Claims (8)

An expansion valve comprising: a power element that senses the temperature and pressure of the refrigerant that has exited the evaporator; and a valve unit that controls the flow rate of the refrigerant sent to the evaporator according to the temperature and pressure sensed by the power element.
An expansion valve having a gap portion between a mounting end surface of a body of the valve portion to which the power element is mounted and a surface of a housing facing the mounting end surface of the power element.   A stopper projecting from the mounting end face, and when the power element is in contact with the stopper, the stopper is mounted on the body in a state of being separated from the mounting end face; The expansion valve according to claim 1, wherein the expansion valve is configured.   The expansion valve according to claim 1, wherein a heat insulating material is disposed in the gap portion.   2. The expansion according to claim 1, wherein the housing on the side facing the mounting end surface is formed with a plurality of through holes communicating with the inside so that a refrigerant can flow in the housing. valve.   The power element has a disk that is disposed in contact with the diaphragm in the housing and transmits the displacement of the diaphragm to the valve body of the valve portion via a shaft, and the disk is attached to the diaphragm. A disk part that abuts and a cylindrical part that extends from the outer peripheral edge of the disk part toward the valve part are integrally formed, and a plurality of slits or holes are formed in the cylindrical part. The expansion valve according to claim 4, wherein a refrigerant can flow inside.   The power element has a disk that is disposed in contact with the diaphragm in the housing and transmits the displacement of the diaphragm to the valve body of the valve portion via a shaft, and the disk includes the diaphragm. 5. The expansion valve according to claim 4, wherein a groove extending in a diametrical direction is formed in a surface to be abutted so that a refrigerant can flow between the diaphragm and the diaphragm.   The power element has a disk that is disposed in contact with the diaphragm in the housing and transmits the displacement of the diaphragm to the valve body of the valve portion through a shaft, and the disk has a thermal conductivity. 5. The expansion valve according to claim 4, wherein the expansion valve is made of a low material. An expansion valve comprising: a power element that senses the temperature and pressure of the refrigerant that has exited the evaporator; and a valve unit that controls the flow rate of the refrigerant sent to the evaporator according to the temperature and pressure sensed by the power element.
The power element is characterized in that a plurality of through-holes communicating with the inside are formed in a housing on the body side of the valve portion to which the power element is mounted, so that a refrigerant can flow in the housing. Expansion valve.

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