WO2018221059A1

WO2018221059A1 - Throttle device and refrigeration cycle system

Info

Publication number: WO2018221059A1
Application number: PCT/JP2018/016165
Authority: WO
Inventors: 裕正 ▲高▼田; 雄一郎當山; 純一横田; 義久新井
Original assignee: 株式会社鷺宮製作所
Priority date: 2017-06-01
Filing date: 2018-04-19
Publication date: 2018-12-06
Also published as: CN110582678B; CN110582678A; JP6636990B2; JP2018204840A

Abstract

A stopper member (12) is molded to a uniform thickness by press working, e.g., a copper-alloy thin plate material. The stopper member (12) has a through-hole (12H) constituting a part of an internal pressure release mechanism, the through-hole (12H) facing the outer peripheral surface of a guide part (18B). If the pressure in a hollow part (14) of the stopper member (12) rapidly increases to or beyond a prescribed value, the trunk part (middle part) of the stopper member (12) swells, whereby a liquid refrigerant in the hollow part (14) is easily released into the inner peripheral part (10a) of a tube body (10) through the through-hole (12H) in an open state.

Description

Throttle device and refrigeration cycle system

The present invention relates to a throttle device and a refrigeration cycle system.

The differential pressure type throttling device can optimally control the refrigerant pressure between the condenser outlet and the evaporator inlet in order to efficiently operate the compressor according to the outside air temperature, and can change the rotation speed of the compressor. Also in the refrigeration cycle system, the refrigerant pressure is optimally controlled in accordance with the rotational speed of the compressor from the viewpoint of labor saving. Such a throttling device is, for example, joined to a primary side pipe connected to a condenser at one end where refrigerant is introduced, and a secondary side pipe connected to an evaporator at the other end where refrigerant flows out. It is joined to.

For example, as shown in Patent Document 1, a differential pressure type throttle device includes a main body case connected to a primary side pipe and a secondary side pipe, a valve seat portion fixed and integrally formed in the main body case, and The main part includes a guide part, a needle valve inserted into a valve port formed in the valve seat part, and a coil spring that urges the needle valve in a direction approaching the valve port. In the throttling device, in addition, a cylindrical stopper portion surrounding the sliding shaft of the needle valve, the coil spring, and the spring receiver is provided in the guide portion. Thereby, it can prevent that a foreign material adheres to biasing means, such as a coil spring, and the stable operativity is obtained. Further, the vibration of the spring member due to the flow of the refrigerant can be reduced to prevent the generation of abnormal noise.

The stopper part has a stopper chamber (hereinafter also referred to as a hollow part) in which liquid refrigerant may stay inside. The stopper chamber is an inner peripheral portion of the main body case through a pressure equalizing hole (see FIG. 1) provided on the side surface of the stopper portion or a gap (see FIG. 4) between the caulking portion of the stopper portion and the outer peripheral portion of the guide portion. Communicated with. Thereby, when the pressure in the primary chamber of the main body case connected to the primary side pipe is changed, the pressure in the stopper chamber is also changed.

In the refrigeration cycle system, for example, as shown in Patent Document 2, hot gas defrost operation may be performed. When hot gas defrost operation is performed, for example, high-temperature and high-pressure gas refrigerant discharged from the compressor is guided between the evaporator and the condenser.

JP 2017-48986 A JP-A-5-71830

When the stopper part in the throttle device shown in Patent Document 1 has a pressure equalizing hole, foreign matter smaller than the diameter of the pressure equalizing hole enters the stopper chamber through the pressure equalizing hole and adheres to the sliding shaft of the needle valve. As a result, the slidability of the sliding shaft may be impaired. In addition, foreign matter may be caught between the lower end surface (contact portion) of the needle valve and the inner surface of the stopper chamber of the stopper portion facing the needle valve, which may cause a change in the bleed flow rate. As a countermeasure for such a case, it is conceivable to set the diameter of the pressure equalizing hole of the stopper portion as small as possible.

However, in the refrigeration cycle system, when hot gas defrost operation is performed, when the temperature around the expansion device provided between the condenser and the evaporator rises rapidly, the stopper chamber is close to the sealed space There is a possibility that the liquid refrigerant filled in the stopper chamber suddenly expands. In such a case, as described above, by setting the diameter of the pressure equalizing hole of the stopper portion as small as possible, there is a possibility that a malfunction may occur in the throttling device, so setting the diameter of the pressure equalizing hole as small as possible is not possible. It ’s not a good idea.

In view of the above-described problems, the present invention is a throttle device and a refrigeration cycle system, and even when the liquid refrigerant in the stopper chamber (hollow part) of the stopper part suddenly expands due to some cause, It is an object of the present invention to provide a throttling device and a refrigeration cycle system that do not cause problems in the apparatus and can prevent foreign matter from entering the stopper chamber (hollow part).

In order to achieve the above-described object, a throttling device according to the present invention is arranged in a pipe that supplies a refrigerant, and has a tube main body that has open end portions that communicate with the pipe at both ends, and an inner peripheral portion of the tube main body. A valve seat having a valve port, a taper that is arranged to be close to or separate from the valve port of the valve seat, and that controls an opening area of the valve port; A needle member having a guide shaft extending toward the upstream side of the flow; and a needle member having a guide shaft portion extending toward the upstream side of the flow of the refrigerant from the position of the valve seat in the inner peripheral portion of the tube body. A guide portion that is movably disposed, a biasing member that is disposed between the guide portion and one open end of the tube body, and biases the needle member in a direction adjacent to the valve port of the valve seat; Needle member guide shaft and attachment An elastically displaceable stopper member that is provided at the end of the guide portion so as to surround the member and has a hollow portion into which refrigerant enters, and when the pressure in the hollow portion of the stopper member exceeds a predetermined value, the inside of the hollow portion And an internal pressure relief mechanism that relieves pressure toward the inner periphery of the tube body.

The internal pressure relief mechanism is formed from an outer peripheral surface of the guide portion and a through hole formed in the stopper member so as to face the outer peripheral surface of the guide portion, and the pressure in the hollow portion of the stopper member is equal to or greater than a predetermined value. In this case, the periphery of the through hole of the stopper member may be separated from the outer peripheral surface of the guide part, and the through hole may be communicated with the hollow part. Further, the internal pressure relief mechanism includes a communication path that is provided in the guide portion and communicates the hollow portion of the stopper member and the outer peripheral surface of the guide portion, and a tongue shape that opens and closes the opening end of the communication passage that opens to the outer peripheral surface of the guide portion. When the pressure in the hollow portion of the stopper member is equal to or higher than a predetermined value, the tongue-shaped piece may be open at the open end of the communication path. Furthermore, the internal pressure relief mechanism is a stopper member. When the pressure in the hollow portion of the stopper member exceeds a predetermined value, the tongue-shaped piece opens the through-hole. It may be a thing.

The refrigeration cycle system according to the present invention includes an evaporator, a compressor, and a condenser, and the above-described throttle device is provided in a pipe disposed between the outlet of the condenser and the inlet of the evaporator. It is characterized by that.

According to the throttling device and the refrigeration cycle system according to the present invention, when the pressure in the hollow portion of the stopper member is equal to or higher than the predetermined value, the internal pressure relief mechanism directs the internal pressure in the hollow portion toward the inner peripheral portion of the tube body. Even if the liquid refrigerant in the hollow portion of the stopper portion suddenly expands due to some reason, the foreign substance can be prevented from entering the hollow portion without causing any trouble in the throttling device.

FIG. 1 is a cross-sectional view showing a configuration of an example of a diaphragm device according to the present invention. FIG. 2 is a cross-sectional view showing an example of a needle subassembly used in the diaphragm device shown in FIG. FIG. 3 is a diagram schematically showing a configuration of an example of a refrigeration cycle system to which an example of the expansion device according to the present invention is applied. FIG. 4 is a characteristic diagram showing the characteristics of the valve opening used for explaining the operation of the example shown in FIG. FIG. 5 is a cross-sectional view for explaining the operation of an example of a needle subassembly used in the aperture device shown in FIG. FIG. 6A is a cross-sectional view showing another example of the needle subassembly used in the throttling device shown in FIG. 1. 6B is an arrow view seen from the arrow VIB in FIG. 6A. FIG. 7 is a cross-sectional view showing still another example of the needle subassembly used in the throttling device shown in FIG. FIG. 8 is a cross-sectional view showing still another example of the needle subassembly used in the throttling device shown in FIG.

FIG. 1 shows a configuration of an example of a diaphragm device according to the present invention.

For example, as shown in FIG. 3, the throttle device is disposed between the outlet of the condenser 6 and the inlet of the evaporator 2 in the piping of the refrigeration cycle system. The throttle device is joined to the primary side pipe Du1 at one end 10E1 of the tube body 10 to be described later, and joined to the secondary side pipe Du2 at the other end 10E2 of the tube body 10 from which the refrigerant flows out. The primary side pipe Du1 connects the outlet of the condenser 6 and the throttle device, and the secondary side pipe Du2 connects the inlet of the evaporator 2 and the throttle device. The compressor 4 is connected between the outlet of the evaporator 2 and the inlet of the condenser 6 by a pipe Du3 joined to the outlet of the evaporator 2 and a pipe Du4 joined to the inlet of the condenser 6. ing. The compressor 4 is driven and controlled by a control unit (not shown). Thereby, the refrigerant | coolant in a refrigerating-cycle system will be circulated along the arrow shown by FIG. 3, for example.

In FIG. 1, the expansion device includes a tube main body 10 joined to the pipe of the above-described refrigeration cycle system, a guide tube 18 fixed to the inner peripheral portion 10 a of the tube main body 10, and a refrigerant integrally formed with the guide tube 18. One of the valve seat 18V, the needle member 20, the coil spring 16 that urges the needle member 20 in the direction approaching the valve seat 18V, and the coil spring 16 A spring receiving member 22 that supports the end portion and a cylindrical stopper member 12 that receives one end of the needle member 20 are included as main elements.

An outer peripheral portion of the fixing portion 18A of the guide tube 18 having an outer diameter smaller than the inner diameter of the tube main body 10 is fixed to an intermediate portion that is separated from the one end 10E2 in the inner peripheral portion 10a of the tube main body 10 by a predetermined distance. .

The guide tube 18 is made of a material such as copper, brass, aluminum, or stainless steel by machining. The guide tube 18 includes a fixed portion 18A that is fixed to the inner peripheral portion 10a of the tube body 10 and a guide portion 18B that slidably guides a guide shaft 20P2 of a needle member 20 described later.

The guide tube 18 is fixed by the protrusions formed by the depressions 10CA1 and 10CA2 of the tube main body 10 by caulking process biting into the grooves 18CA1 and 18CA2 on the outer peripheral portion of the fixing portion 18A. The guide tube 18 has a metal stopper member 12 on the outer peripheral portion of the end portion of the guide portion 18B closest to the one end 10E1 of the tube main body 10.

The stopper member 12 is formed with a uniform thickness, for example, by press working with a copper alloy thin plate material. By forming the stopper member 12 by press molding, it is possible to avoid problems due to expansion of the refrigerant at a relatively low cost. The copper alloy thin plate material has, for example, a thickness of 3% to 10% of the inner diameter of the stopper member 12, and preferably a thickness of 0.3 mm to 0.9 mm. By making the thickness of the side surface of the stopper 3 to 10% of the inner diameter of the stopper member 12, the stopper member 12 is easily deformed in the radial direction by the liquid refrigerant expanded, and liquid impact and The stopper member 12 is not deformed by the application of an undesired external force.

As shown in the enlarged view of FIG. 2, one end of the stopper member 12 is guided by a projection formed by the depression 12CA1 of the stopper member 12 by caulking into the groove 18CB1 at the end of the guide portion 18B. It is fixed to. The caulking recesses 12CA1 are formed at a plurality of locations, for example, three locations with a predetermined interval along the circumferential direction of the stopper member 12. The cylindrical stopper member 12 has a closed end at the other end, and is structured to cover the coil spring 16 and the spring receiving member 22. The stopper member 12 extends from the guide portion 18B toward the one end 10E1 side of the tube body 10. In addition, the closed end portion has a flat inner surface. The inner surface of the closed end portion receives the end surface 20P5 of the adjusting screw 20P4. The adjusting screw 20P4 is formed integrally with one end of a guide shaft 20P2 of the needle member 20 described later, and is screwed into the female screw 22A at one end of the spring receiving member 22. A hollow portion 14 into which a liquid refrigerant enters is formed inside the stopper member 12.

A predetermined gap is formed between the inner peripheral surface of the stopper member 12 other than the recess 12CA1 and the outer peripheral surface of the end portion of the guide portion 18B other than the groove 18CB1. Accordingly, the refrigerant supplied from the one end 10E1 side of the tube main body 10 along the arrow shown in FIG. 1 flows into the hollow portion 14 of the stopper member 12 through the gap or the gap between the guide portion 18B and the guide shaft 20P2. The

Further, a through hole 12H constituting a part of the internal pressure relief mechanism is formed facing the outer peripheral surface of the guide portion 18B at a predetermined distance from the recess 12CA1 of the stopper member 12 toward the closed end. Yes. The diameter of the through-hole 12H is set to a dimension that is greater than or equal to the thickness of the stopper member 12, for example. In FIG. 2, the through hole 12 H is closed by bringing the peripheral edge of the through hole 12 H into contact with the outer peripheral surface of the guide portion 18 B. On the other hand, as shown in FIG. 5, when the pressure in the hollow portion 14 suddenly rises above a predetermined value, the peripheral portion of the through-hole 12 H is guided by the swelling of the trunk portion (middle abdomen) of the stopper member 12. Separated from the outer peripheral surface of the portion 18B, a gap is formed between them.

Therefore, the liquid refrigerant in the hollow portion 14 is directed in the direction indicated by the arrow LQ through the open through-hole 12H, that is, toward the substantially radial direction of the trunk portion (middle portion) of the stopper member 12. It will be discharged into the inner periphery 10 a of the main body 10. Moreover, since the through-hole 12H is provided on the side surface of the stopper member 12, the liquid refrigerant that has expanded is passed through the through-hole 12H and flows into the pipe, so that no valve is required. Thereby, an internal pressure relief mechanism is formed by the through hole 12H of the stopper member 12 and the outer peripheral surface of the guide portion 18B. The number of through holes 12H is not limited to such an example, and a plurality of through holes may be formed.

In the guide tube 18, a guide portion 18 B is formed in an upstream portion of a communication hole 18 C described later. A guide shaft 20P2 of the needle member 20 is slidably fitted into the hole 18b of the guide portion 18B.

The valve port 18P and the hole 18b of the valve seat 18V of the fixed portion 18A in the guide tube 18 are formed on a common central axis. At that time, since the guide portion 18B and the fixed portion 18A of the guide tube 18 are integrally formed, the valve port 18P and the hole portion 18b of the valve seat 18V have a common central axis so that the centers thereof coincide with each other. It becomes easy to process on the line with high accuracy.

A communication hole 18C is formed directly below the valve seat 18V between the valve seat 18V and the guide portion 18B in the fixed portion 18A. The communication hole 18 C that penetrates the guide tube 18 in the radial direction allows the valve port 18 P to communicate between the outer peripheral portion of the guide tube 18 and the inner peripheral portion 10 a of the tube main body 10.

The valve seat 18V in the guide tube 18 has a valve port 18P into which the tapered portion 20P1 in the needle member 20 is inserted at the center of the inside. The valve port 18P has a circular opening that penetrates along the central axis of the valve seat 18V with a predetermined uniform diameter. The valve port 18P is not limited to such an example. For example, the valve port 18P may pierce toward the one end 10E1 along the central axis of the valve seat 18V.

As shown in FIG. 2, a divergent portion 18d having an inner diameter gradually larger toward the downstream side than the diameter of the valve port 18P is provided at the downstream portion of the guide tube 18 from the valve seat 18V. It is formed inside. The divergent portion 18d is continuous with the inner peripheral portion 18e of the cylindrical fixing portion 18A.

As shown in FIG. 2, the needle member 20 is made of a material such as brass or stainless steel by machining, and has a tapered portion 20P1 formed facing the valve seat 18V, and a hole in the guide portion 18B. The guide shaft portion 20P2 slidably fitted to the portion 18b, the overhang portion 20F and the connecting projection piece 20f connected to the base portion of the tapered portion 20P1, and the spring receiving member connection formed at the tip of the guide shaft portion 20P2 The portion 20P3 and the adjustment screw 20P4 are configured as main elements.

The minimum diameter portion of the truncated conical tapered portion 20P1 having a predetermined taper angle is set to be slightly smaller than the diameter of the guide shaft portion 20P2. The tapered portion 20P1 is a base having a diameter larger than the diameter of the valve port 18P when the end surface 20P5 of the adjusting screw 20P4 of the needle member 20 is brought into contact with the inner surface of the closed end of the stopper member 12, that is, a tension described later. A connecting portion with the outlet portion 20F is provided at a position separated from the valve port 18P by a predetermined distance.

The spring receiving member 22 is fixed to the spring receiving member connecting portion 20P3 of the needle member 20 by caulking. The spring receiving member connecting portion 20P3 is formed by, for example, an annular groove. The spring receiving member 22 is fixed by the protrusion formed by the depression 22CA1 of the spring receiving member 22 by caulking process biting into the groove of the spring receiving member connecting portion 20P3. One end of the coil spring 16 is supported by the spring support portion 22F of the spring receiving member 22 facing the above-described guide portion 18B. The spring support portion 22F protruding to the side is integrally formed at a position separated by a predetermined distance in the direction of approaching the guide portion 18B from the above-described depression 22CA1. The other end of the coil spring 16 is supported by the spring receiving portion 18f of the guide portion 18B described above. The end face 18g of the abutting portion connected to the spring receiving portion 18f of the guide portion 18B and the end portion 22G of the cylindrical portion of the spring supporting portion 22F of the spring receiving member 22 are separated from each other by a predetermined distance. A coil spring 16 is wound around the cylindrical portion of the spring support portion 22F of the spring receiving member 22. Accordingly, if the needle member 20 is moved toward the other end 10E2 by a predetermined value or more, the end surface 18g of the contact portion of the guide portion 18B and the end portion 22G of the cylindrical portion of the spring support portion 22F Is in contact, the movement of the needle member 20 is restricted. Therefore, it is avoided that the coil spring 16 is excessively compressed to a predetermined value or more.

The male screw of the adjusting screw 20P4 formed integrally with the spring receiving member connecting portion 20P3 of the needle member 20 is screwed into the hole of the female screw 22A on the inner peripheral portion of the spring receiving member 22. The hole of the female screw 22A extends in a direction away from the recess 22CA1 with respect to the guide portion 18B. The adjusting screw 20P4 adjusts the urging force of the coil spring 16.

In the throttling device, the outer peripheral portion of the tapered portion 20P1 of the needle member 20 has an opening end portion of the valve port 18P due to a differential pressure (difference between the refrigerant inlet pressure on the one end 10E1 side and the refrigerant outlet pressure on the other end 10E2 side). The separation start timing at which the separation starts from the peripheral edge of the coil spring 16 is set based on the biasing force of the coil spring 16. The spring constant of the coil spring 16 is set to a predetermined value.

After the biasing force of the coil spring 16 is adjusted by the adjusting screw 20P4, the protrusion formed by the depression 22CA1 of the spring receiving member 22 by caulking process bites into the groove of the spring receiving member connecting portion 20P3, thereby adjusting the screw 20P4. The position with respect to the spring receiving member 22 is fixed.

When the end surface 20P5 of the adjusting screw 20P4 is brought into contact with the flat inner surface of the closed end of the stopper member 12, the taper is formed at a position corresponding to the open end of the valve port 18P on the outer periphery of the taper 20P1 of the needle member 20. The outer peripheral part of 20P1 is arrange | positioned so that a predetermined clearance may be formed with respect to the periphery of the opening end part of the valve port 18P. At that time, a throttle portion is formed between the tapered portion 20P1 of the needle member 20 and the open end portion of the valve port 18P. The throttle portion refers to a portion (narrowest portion) where the intersection of the perpendicular line from the peripheral edge of the valve port 18P to the bus bar of the tapered detail 20P1 and the bus bar of the tapered detail 20P1 is closest to the edge of the valve port 18P. The area of the conical surface drawn by the perpendicular is the opening area of the diaphragm.

When the pressure of the refrigerant in the tube body 10 is equal to or lower than a predetermined value, the end face 20P5 of the adjustment screw 20P4 is stopped at a predetermined pressure corresponding to the difference between the biasing force of the coil spring 16 and the pressure of the refrigerant from the primary side pipe Du1. The member 12 is in contact with the inner surface of the closed end.

The predetermined bleed amount passing through the above-mentioned throttle portion is set by the amount of the predetermined gap formed with respect to the peripheral edge of the opening end of the valve port 18P. Further, since the end face 20P5 of the adjusting screw 20P4 in the spring receiving member 22 of the needle member 20 is in contact with the inner surface of the closed end of the stopper member 12, the secondary side acting on the urging force of the coil spring 16 and the needle member 20 is applied. Undesirable pressure from the needle member 20 prevents the tapered portion 20P1 from biting into the open end of the valve port 18P of the valve seat 18V.

The above-described guide tube 18, the needle member 20 inserted into the valve port 18P and the hole 18b of the guide tube 18, the spring receiving member 22 into which the adjusting screw 20P4 of the needle member 20 is screwed in a predetermined amount, and the spring receiving member 22 And the coil spring 16 disposed between the guide tube 18 and the end of the guide portion 18B of the guide tube 18 form a needle subassembly.

In such a configuration, when the force acting on the needle member 20 due to the refrigerant pressure does not exceed the urging force of the coil spring 16, as described above, when the refrigerant is supplied through the primary side pipe Du1, the refrigerant pressure is The pressure is reduced by passing through the one end 10E1 of the tube main body 10, the inner peripheral portion 10a of the tube main body 10 and the outer peripheral portion of the stopper member 12 through the communication path 18C and the above-described throttle portion, and then the refrigerant is guided to the guide tube. 18 is discharged from the other end 10E2 through the inner peripheral portion 18e of the fixed portion 18A with a predetermined bleed amount.

Furthermore, when the force acting on the needle member 20 due to the pressure of the refrigerant exceeds the urging force of the coil spring 16, the refrigerant flowing through the above-described throttle portion presses the needle member 20 in a direction further away from the peripheral edge of the valve port 18P. It will be. Accordingly, as shown in FIG. 4, when the differential pressure P is the value P1, the differential pressure P increases from the differential pressure P1 from the state where the valve opening (opening area of the throttle portion) VP is the predetermined value V1. As the valve opening degree VP increases, the valve opening VP increases linearly according to the characteristic line La. Further, when the differential pressure P increases to a predetermined value P2, the valve opening VP reaches a predetermined value V2 as the rated valve opening.

Furthermore, the temperature of the expansion device rises due to some cause, for example, due to hot gas defrost operation or the like, and the pressure of the liquid refrigerant in the hollow portion 14 of the stopper member 12 is rapidly increased to a predetermined value or more. As shown in FIG. 5, the body portion (middle abdomen) of the stopper member 12 swells so that the liquid refrigerant in the hollow portion 14 passes through the through-hole 12H that is opened. In the direction indicated by the arrow LQ, that is, in the radial direction of the stopper member 12, the tube body 10 is easily discharged toward the inner peripheral portion 10a. Therefore, there is no possibility that foreign matter will enter the hollow portion 14 from the outside, and there is no problem with the diaphragm device. By providing the stopper member 12 with the through-hole 12H facing the fitting portion of the guide portion 18B, the pressure increase in the stopper member 12 can be suppressed, and foreign substances in the fluid flow into the stopper member 12 during normal operation. There is no fear. Therefore, the operability is not impaired by the foreign matter. After the liquid refrigerant is released due to elastic deformation of the stopper member 12, the stopper member 12 returns to the initial shape state shown in FIG. There is no change.

FIG. 6A shows an enlarged configuration of another example of a needle subassembly used in an example of a diaphragm device according to the present invention. In FIG. 6A, the same components as those in the example shown in FIG. 1 are denoted by the same reference numerals, and redundant description thereof is omitted.

The needle subassembly includes a guide tube 28, a needle member 20 inserted into the valve port 28P and the hole 28b of the guide tube 28, a spring receiving member 22 into which an adjustment screw 20P4 of the needle member 20 is screwed in a predetermined amount, a spring The coil spring 16 is disposed between the receiving member 22 and the end portion of the guide portion 28B of the guide tube 28.

The guide tube 28 is made of a material such as copper, brass, aluminum, or stainless steel by machining. The guide tube 28 includes a fixed portion 28A that is fixed to the inner peripheral portion 10a of the tube main body 10 shown in FIG. 1 and a guide portion 28B that slidably guides the guide shaft 20P2 of the needle member 20. .

The guide tube 28 is fixed by the protrusions formed by the depressions 10CA1 and 10CA2 of the tube main body 10 by caulking process biting into the grooves 28CA1 and 28CA2 on the outer peripheral portion of the fixing portion 28A. The guide tube 28 has a metal stopper member 32 on the outer peripheral portion of the end portion of the guide portion 28B closest to the one end 10E1 of the tube body 10. The cylindrical stopper member 32 is formed, for example, with a uniform thickness by press working with a copper alloy thin plate material. The copper alloy thin plate material has, for example, a thickness of 3% to 10% of the inner diameter of the stopper member 32, preferably a thickness of 0.3 mm to 0.9 mm.

One end of the stopper member 32 is fixed to the guide portion 28B by the protrusion formed by the dent 32CA1 of the stopper member 32 by caulking process biting into the groove 28CB1 at the end portion of the guide portion 28B. The caulking recess 32CA1 is formed at a plurality of locations, for example, 3 locations with a predetermined interval along the circumferential direction of the stopper member 32. The stopper member 32 has a closed end at the other end and is structured to cover the coil spring 16 and the spring receiving member 22.

The stopper member 32 extends from the guide portion 28B toward the one end 10E1 side of the tube body 10. In addition, the closed end portion has a flat inner surface. The inner surface of the closed end portion receives the end surface 20P5 of the adjusting screw 20P4. Inside the stopper member 32, a hollow portion 24 into which a liquid refrigerant enters is formed.

A predetermined gap is formed between the inner peripheral surface of the stopper member 32 other than the recess 32CA1 and the outer peripheral surface of the end portion of the guide portion 28B other than the groove 28CB1. Therefore, the refrigerant supplied from the one end 10E1 side of the tube body 10 flows into the hollow portion 24 of the stopper member 32 through the gap or the gap between the guide portion 28B and the guide shaft 20P2.

Further, at a position separated from the recess 32CA1 in the stopper member 32 by a predetermined distance toward the closed end, as shown in a partially enlarged view in FIG. 6B, a tongue constituting a part of the internal pressure relief mechanism. The shaped piece 32V is formed to be elastically displaceable. The base end portion of the tongue-like piece 32 V is formed integrally with other portions of the stopper member 32. The end portion of the tongue-like piece 32V can be brought close to or separated from the inner peripheral edge of the opening 32a based on its own elastic force. A communication passage 28R is formed in a portion facing the tongue-like piece 32V inside the guide portion 28B. One end of the communication path 28R opens into the hollow portion 24, and the other end of the communication path 28R faces the tongue-like piece 32V and opens on the outer peripheral surface of the guide portion 28B. The opening diameter of the other end of the communication path 28R is set to be smaller than the width W of the end portion of the tongue-like piece 32V, as shown partially enlarged in FIG. 6B.

In FIG. 6A, for example, when the pressure in the hollow portion 24 suddenly rises to a predetermined value or more, the guide portion so that the end portion of the tongue-like piece 32V opens the opening end of the other end of the communication passage 28R. The state separated from the outer peripheral surface of the part 28B is shown. As a result, the liquid refrigerant in the hollow portion 24 is discharged into the inner peripheral portion 10a of the tube body 10 in the direction indicated by the arrow LQ via the communication path 28R, that is, toward the downstream side.

A guide portion 28B is formed in a portion of the guide tube 28 on the upstream side of a later-described communication hole 28C. A guide shaft 20P2 of the needle member 20 is slidably fitted in the hole 28b of the guide portion 28B.

The valve port 28P and the hole 28b of the valve seat 28V of the fixed portion 28A in the guide tube 28 are formed on a common central axis. At this time, since the guide portion 28B and the fixed portion 28A of the guide tube 28 are integrally formed, the valve port 28P and the hole portion 28b of the valve seat 28V have a common central axis so that their centers coincide with each other. It becomes easy to process on the line with high accuracy.

Between the valve seat 28V and the guide portion 28B in the fixed portion 28A, a communication hole 28C is formed immediately below the valve seat 28V. A communication hole 28 C that penetrates the guide tube 28 in the radial direction allows the valve port 28 P to communicate between the outer peripheral portion of the guide tube 28 and the inner peripheral portion 10 a of the tube main body 10.

The valve seat 28 V in the guide tube 28 has a valve port 28 P into which the tapered portion 20 P 1 in the needle member 20 is inserted in the center of the inside. The valve port 28P has a circular opening penetrating along the central axis of the valve seat 28V with a predetermined uniform diameter. The valve port 28P is not limited to such an example. For example, the valve port 28P may penetrate in a divergent shape toward the one end 10E1 along the central axis of the valve seat 28V.

In the downstream portion of the guide tube 28 from the valve seat 28V, a divergent portion 28d whose inner diameter gradually increases toward the downstream side than the diameter of the valve port 28P is formed inside the fixed portion 28A. The divergent portion 28d is continuous with the inner peripheral portion 28e of the cylindrical fixing portion 28A.

In such a configuration, the temperature of the expansion device rises due to some cause, for example, due to hot gas defrost operation or the like, and the pressure in the hollow portion 24 of the stopper member 32 is rapidly increased to a predetermined value or more. Even then, as shown in FIG. 6A, the end of the tongue-like piece 32V of the stopper member 32 is caused by the pressure in the hollow portion 24 so as to open the open end of the other end of the communication path 28R. When the liquid refrigerant in the hollow portion 24 is separated, the liquid refrigerant in the hollow portion 24 is directed in the direction indicated by the arrow LQ through the open communication path 28R, that is, in the inner peripheral portion 10a of the tube body 10 on the downstream side. Will be released easily. Therefore, there is no risk that foreign matter normally enters the hollow portion 24 from the outside, and no trouble is caused in the expansion device.

FIG. 7 shows an enlarged configuration of still another example of the needle subassembly used in the example of the diaphragm device according to the present invention. In FIG. 7, the same components as those in the example shown in FIG. 1 are denoted by the same reference numerals, and redundant description thereof is omitted.

The needle subassembly includes a guide tube 18, a needle member 20 inserted into the valve port 18P and the hole 18b of the guide tube 18, a spring receiving member 22 into which an adjustment screw 20P4 of the needle member 20 is screwed in a predetermined amount, a spring The coil spring 16 is disposed between the receiving member 22 and the end portion of the guide portion 18B of the guide tube 18.

In the example shown in FIG. 1, the through hole 12 H constituting a part of the internal pressure relief mechanism is a guide portion of the guide tube 18 at a position separated from the recess 12 CA 1 in the stopper member 12 by a predetermined distance toward the closed end portion. In the example shown in FIG. 7, instead, the through hole 42 H constituting a part of the internal pressure relief mechanism is formed on the outer peripheral surface of the guide portion 18 B of the guide tube 18. The tongue-shaped piece 36 that opens and closes the through hole 42 H is joined to the outer peripheral portion of the stopper member 42.

The stopper member 42 is formed of, for example, a copper alloy thin plate material with a uniform thickness by press working. The copper alloy thin plate material has, for example, a thickness of 3% to 10% of the inner diameter of the stopper member 12, and preferably a thickness of 0.3 mm to 0.9 mm.

The one end of the stopper member 42 is fixed to the guide portion 18B by the protrusion formed by the recess 42CA1 of the stopper member 42 by caulking process biting into the groove 18CB1 at the end portion of the guide portion 18B. The caulking recess 42CA1 is formed at a plurality of locations, for example, 3 locations with a predetermined interval along the circumferential direction of the stopper member 42. The cylindrical stopper member 42 has a closed end at the other end, and has a structure that covers the coil spring 16 and the spring receiving member 22.

The stopper member 42 extends toward the one end 10E1 side of the tube body 10 from the guide portion 18B. In addition, the closed end portion has a flat inner surface. The inner surface of the closed end portion receives the end surface 20P5 of the adjusting screw 20P4. Inside the stopper member 42, a hollow portion 24 into which a liquid refrigerant enters is formed.

A predetermined gap is formed between the inner peripheral surface of the stopper member 42 other than the recess 42CA1 and the outer peripheral surface of the end portion of the guide portion 18B other than the groove 18CB1. Accordingly, the refrigerant supplied from the one end 10E1 side of the tube main body 10 flows into the hollow portion 24 of the stopper member 42 through the gap.

Further, a circular through hole 42H constituting a part of the internal pressure relief mechanism is formed at a position spaced apart from the recess 42CA1 in the stopper member 42 by a predetermined distance toward the closed end. The through hole 42 H communicates with the hollow portion 24. The diameter of the through hole 42H is set, for example, to a dimension equal to or larger than the thickness of the stopper member 42. A tongue-like piece 36 that opens and closes the through hole 42H is joined to the periphery of the through hole 42H. The base end portion of the tongue-like piece 36 is joined to a position in the stopper member 42 close to the recess 42CA1. The distal end portion of the tongue-like piece 36 is elastically displaceable, and is separated from the through hole 42H by the first position where the through hole 42H is closed by contacting the outer peripheral surface of the stopper portion 42 and the pressure in the hollow portion 24. The second position where the through hole 42H is opened is taken. In FIG. 7, the second position of the end portion of the tongue-like piece 36 is shown. Thereby, the liquid refrigerant in the hollow portion 24 is discharged into the inner peripheral portion 10a of the tube body 10 in the direction indicated by the arrow LQ, that is, toward the upstream side, through the open through hole 42H. It will be.

In such a configuration, the temperature of the expansion device rises due to some cause, for example, due to hot gas defrost operation or the like, and the pressure in the hollow portion 24 of the stopper member 42 is rapidly increased to a predetermined value or more. Even then, as shown in FIG. 7, the end of the tongue-like piece 36 of the stopper member 42 is separated due to the pressure in the hollow portion 24 so as to open the through hole 42H. When this occurs, the liquid refrigerant in the hollow portion 24 is easily discharged into the inner peripheral portion 10a of the tube main body 10 through the through hole 42H in the direction indicated by the arrow LQ, that is, toward the upstream side. . Therefore, there is no risk that foreign matter normally enters the hollow portion 24 from the outside, and no trouble is caused in the expansion device.

FIG. 8 shows an enlarged configuration of still another example of the needle subassembly used in the example of the diaphragm device according to the present invention. In FIG. 8, the same components as those in the example shown in FIG. 7 are denoted by the same reference numerals, and the duplicate description thereof is omitted.

The tongue-like piece 36 of the stopper member 42 shown in FIG. 7 discharges the liquid refrigerant in the hollow portion 24 toward the upstream side, but instead, the tongue of the stopper member 42 shown in FIG. The shape piece 38 discharges the liquid refrigerant in the hollow portion 24 toward the downstream side. A tongue-like piece 38 that opens and closes the through hole 42H is joined to the periphery of the through hole 42H. The base end portion of the tongue-like piece 38 is joined to a position adjacent to the through hole 42H separated from the recess 42CA1 in the stopper member 42. The distal end portion of the tongue-like piece 38 is elastically displaceable, and is separated from the through hole 42H by the first position where the through hole 42H is closed by contacting the outer peripheral surface of the stopper portion 42 and the pressure in the hollow portion 24. The second position where the through hole 42H is opened is taken. In FIG. 8, the second position of the end portion of the tongue-like piece 38 is shown. Even in such a configuration, the temperature of the expansion device rises due to some cause, for example, due to hot gas defrost operation or the like, and the pressure in the hollow portion 24 of the stopper member 42 is rapidly increased to a predetermined value or more. Even when the liquid refrigerant in the hollow portion 24 passes through the through-hole 42H opened, the liquid refrigerant in the inner peripheral portion 10a of the tube body 10 is directed in the direction indicated by the arrow LQ, that is, toward the downstream side. Will be released.

Although the above embodiments have been described in detail with reference to the drawings, the specific configuration to which an example of the present invention can be applied is not limited to these embodiments, and departs from the gist of the present invention. Design changes and the like within a range not to be performed (for example, the position and shape of the hole, the shape of each member, etc.) are also included in the present invention. In the description of the present specification, an example of a system using a hot gas defrost system is shown as an example of the cause of the liquid refrigerant body expansion. However, another reason for the liquid refrigerant to expand is that the temperature of the expansion unit (abrupt temperature rise) when used in various other refrigeration cycles such as the normal cooling refrigeration cycle and heat pump cycle. (Not limited to)). Further, the temperature rise of the expansion device portion does not necessarily occur during the refrigeration cycle operation, but may occur during the non-operation.

Claims

A tube main body that is disposed in a pipe for supplying a refrigerant and has open end portions that communicate with the pipe at both ends;
A valve seat disposed on the inner periphery of the tube body and having a valve port;
A tapered portion that is arranged to be close to or away from the valve port of the valve seat and controls the opening area of the valve port, and is connected to the end of the tapered portion and separated from the valve port and upstream of the refrigerant flow. A guide shaft portion extending toward the needle member,
A guide portion disposed on the upstream side of the flow of the refrigerant from the position of the valve seat in the inner peripheral portion of the tube body, and a guide shaft portion of the needle member is slidably disposed;
A biasing member disposed between the guide portion and one open end of the tube main body, and biasing the needle member in a direction approaching the valve port of the valve seat;
An elastically displaceable stopper member provided at an end of the guide portion so as to surround the guide shaft portion of the needle member and the biasing member, and having a hollow portion into which the refrigerant enters;
When the pressure in the hollow portion of the stopper member is equal to or greater than a predetermined value, an internal pressure relief mechanism that releases the internal pressure in the hollow portion toward the inner peripheral portion of the tube body,
A diaphragm device comprising:
The internal pressure relief mechanism is formed from an outer peripheral surface of the guide portion and a through hole formed in the stopper member so as to face the outer peripheral surface of the guide portion,
When the pressure in the hollow portion of the stopper member is equal to or greater than a predetermined value, the periphery of the through hole of the stopper member is separated from the outer peripheral surface of the guide portion, and the through hole communicates with the hollow portion. The aperture device according to claim 1.
The internal pressure relief mechanism includes a communication path that is provided in the guide portion and communicates a hollow portion of the stopper member and an outer peripheral surface of the guide portion, and an opening end in the communication passage that opens to the outer peripheral surface of the guide portion. A tongue-shaped piece that opens and closes,
2. The aperture device according to claim 1, wherein when the pressure in the hollow portion of the stopper member is equal to or greater than a predetermined value, the tongue-shaped piece opens the open end of the communication path.
The internal pressure relief mechanism is formed from a through hole formed in the body portion of the stopper member, and a tongue-shaped piece that opens and closes the through hole,
2. The aperture device according to claim 1, wherein when the pressure in the hollow portion of the stopper member is equal to or higher than a predetermined value, the tongue-shaped piece opens the through hole.
An evaporator, a compressor, and a condenser;
5. A refrigeration cycle system, wherein the expansion device according to claim 1 is provided in a pipe disposed between an outlet of the condenser and an inlet of the evaporator.