JP5684746B2 - Expansion valve - Google Patents

Description

  The present invention relates to an expansion valve that is provided in a heat pump refrigeration cycle and that functions to throttle the refrigerant in the first flow direction of the refrigerant, and that allows a large flow rate to flow by minimizing pressure loss.

  Conventionally, many heat pump refrigeration cycles are provided with an expansion valve on the outdoor heat exchanger side (outdoor unit). In this case, the refrigerant expanded by the expansion valve passes through a long pipe to the indoor heat exchanger. Inflow. For this reason, there is a problem that pressure loss is likely to occur in the expanded refrigerant, and it is difficult to control the flow rate in the expansion valve. This is the same when the expansion valve is provided on the indoor heat exchanger side.

  On the other hand, JP 2009-287913 A (Patent Document 1) discloses that in a heat pump refrigeration cycle, an indoor heat exchanger performs a throttling function including flow control in the cooling mode, and outdoor heat exchange in the heating mode. There has been proposed an expansion valve that can perform a throttle function on the vessel side.

  Further, the expansion valve of Patent Document 1 functions to throttle the refrigerant with respect to the first flow direction of the refrigerant, and to flow a large flow rate by reducing the pressure loss as much as possible with respect to the second flow direction. And a valve seat member (2, 8) as an auxiliary valve, and the valve seat member (2, 8) is configured to slide in the axial direction within the valve housing (1, 7). The second port (12) opened by the valve seat member (2) has substantially the same diameter as the inner diameter of the joint pipe (12a), and the second port of the valve seat ring (721) opened by the valve seat member (8) ( 71) has the same diameter as the inner diameter of the joint pipe (722).

  By the way, the joint pipe (12a, 722) is attached to the valve housing (1, 7) by brazing. The brazing is inserted into the valve housing through the main body 1a in a state where a brazing material is fitted into the joint pipe. Then, the assembled assembly is heated in a fluxless furnace of the brazing apparatus. A brazing technique for heating in a fluxless furnace is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-139169 (Patent Document 2).

JP 2009-287913 A JP 2002-139169 A

  The expansion valve disclosed in Patent Document 1 has the following problems because the inner diameter of the second port and the inner diameter of the joint pipe communicating with the second port are the same diameter (substantially the same diameter). In the brazing process, a brazing material is fitted into the base of the joint pipe on the valve housing side and melts. The molten brazing material flows between the insertion hole of the valve housing and the outer periphery of the joint pipe by a capillary phenomenon.

  The clearance between the insertion hole of the valve housing and the outer periphery of the joint pipe is set according to the volume of the brazing material to be used. However, depending on the atmospheric conditions of the brazing device, it may be difficult to control the flow rate of the melted brazing material. When the brazing material flows out to the sub valve seat through the second port, the sub valve seat and Since the brazing material adheres to the contact surface with the valve and makes the shape non-uniform, there is a risk of valve leakage.

  In the heat pump refrigeration cycle, the sub-valve is moved in the valve housing to perform the function of constricting the refrigerant with respect to the first flow direction of the refrigerant and the pressure with respect to the second flow direction. In an expansion valve designed to allow a large flow rate with minimal loss, ensure that the brazing material does not flow to the sub-valve seat around the second port where the sub-valve sits, and ensure the accuracy of the sub-valve seat It is an object to prevent valve leakage and the like.

The expansion valve according to claim 1 includes a valve housing constituting a cylindrical main valve chamber, a first port communicating with the main valve chamber, a second port communicating with an axial end of the main valve chamber, A sub-valve disposed in the main valve chamber so as to be movable in the axial direction of the main valve chamber, and having a valve port between the main valve chamber and the second port, and the axial movement with respect to the sub-valve A valve body that opens and closes the valve port, and when the refrigerant flows from the first port to the second port, the sub valve is connected to the sub port around the second port due to a differential pressure between the first port and the second port. When the second port is closed by being seated on the valve seat and when the refrigerant flowing to the valve port is throttled by the valve body and the refrigerant flows in the opposite direction, the pressure difference between the second port and the first port The auxiliary valve is separated from the second port and the second port is fully opened. In Unishi was expansion valve, an inner diameter of the same diameter of the joint tube communicating with the second port and the second port, the inner seat ring having the same diameter as the joint tube and the second port, the valve housing respect, the valve seat ring and the main valve chamber side attached together attaches said the valve seat ring joint pipe Rutotomoni, said valve housing and該継hand at the periphery of該継Tekuda Gallery is configured to be attached, and the open end of the joint pipe side of the second port was all around the inner peripheral surface at a location adjacent to the joint pipe inner peripheral surface of the second port, said A plurality of grooves for storing the molten brazing material are formed inside the two ports. In the claims and the specification, “the inner diameter is the same diameter” is a concept including the case where the diameter is exactly the same and the case where the diameter is substantially the same (substantially the same diameter).

  According to the expansion valve of the first aspect, the brazing material that has flowed from the joint pipe to the second port in the brazing process at the time of attaching the joint pipe to the valve housing, even when the amount of the brazing material melted out is large. It is possible to prevent the brazing material from accumulating in the pipe-side groove and reaching the sub-valve seat on which the sub-valve is seated, ensuring the accuracy of the sub-valve seat, and preventing valve leakage and the like.

Further, since there are a plurality of grooves, adhesion of the brazing material to the auxiliary valve seat can be reliably prevented.

Further, since the second port is formed by a valve seat ring separate from the valve housing, it is easy to form the groove for storing the brazing material.

It is a longitudinal cross-sectional view of the throttle state of the expansion valve of the embodiment of the present invention. It is a longitudinal cross-sectional view of the fully open state of the expansion valve. It is a figure which shows a part of assembly process of the expansion valve in embodiment of this invention. It is a figure explaining the effect | action of the groove | channel which stores the brazing | wax material of the expansion valve in embodiment of this invention. It is the top view and longitudinal cross-sectional view of a subvalve in embodiment of this invention. It is a figure which shows the heat pump type | mold refrigerating cycle provided with the expansion valve of embodiment of this invention.

Next, an embodiment of the expansion valve of the present invention will be described with reference to the drawings. FIG. 6 is a view showing a heat pump refrigeration cycle provided with the expansion valve of the embodiment. First, the heat pump refrigeration cycle according to the embodiment will be described based on FIG. 6. 6, reference numeral 10 _1, 10 ₂ is the first expansion valve and the second expansion valve embodiments of the present invention, the first expansion valve 10 ₁ is mounted on the outdoor unit 100, a second expansion the valve 10 ₂ is mounted in the indoor unit 200. The expansion valves 10 ₁ and 10 ₂ , the outdoor heat exchanger 20, the indoor heat exchanger 30, the flow path switching valve 40, and the compressor 50 are connected by conduits as shown in the figure, and constitute a heat pump type refrigeration cycle. ing.

The flow path of the refrigeration cycle is switched to two flow paths of “cooling mode” and “heating mode” by the flow path switching valve 40. In the cooling mode, the refrigerant compressed by the compressor 50 flows into the outdoor heat exchanger 20 from the flow path switching valve 40, flows through the pipe line a via the _first expansion valve 101, and the second expansion valve 10. Inflow into ₂ . Then, the refrigerant is expanded by the _second expansion valve 102 and flows into the indoor heat exchanger 30. The refrigerant that has flowed into the indoor heat exchanger 30 flows into the compressor 50 via the flow path switching valve 40. In the heating mode, the refrigerant compressed by the compressor 50 flows into the indoor heat exchanger 30 from the flow path switching valve 40, passes through the second expansion valve 10 ₂ , the pipe line a, and enters the first expansion valve 10 ₁ . Inflow. Then, the refrigerant is expanded by the _first expansion valve 101 and circulated in the order of the outdoor heat exchanger 20, the flow path switching valve 40, and the compressor 50.

Here, the expansion valves 10 ₁ and 10 ₂ take a fully open state in which the refrigerant flow rate is not controlled and a throttle state in which the refrigerant flow rate is controlled. In the fully open state, the refrigerant flows in from the joint pipe 12 and flows out from the joint pipe 11. To do. In the throttled state, the refrigerant flows in from the joint pipe 11 and flows out from the joint pipe 12. That is, in the cooling mode ₁ first expansion valve 10 is in a state the second expansion valve 10 ₂ is squeezed with the fully open state, and in the heating mode, the second expansion valve 10 ₂ are first in the fully open state expansion valve 10 ₁ is squeezed state. Also, in either mode of cooling mode and heating mode, the first expansion valve 10 ₁ and the second conduit refrigerant flow in a connecting the expansion valve 10 ₂ becomes the large flow rate, the expansion valve before having a stop function Pressure loss can be reduced, and the driving ability is improved.

Next, the expansion valves 10 ₁ and 10 ₂ of the embodiment will be described. 1 is a longitudinal sectional view of the expansion valve of the embodiment in the throttled state, FIG. 2 is a longitudinal sectional view of the expansion valve in a fully opened state, and FIG. 3 is a diagram showing a part of the assembly process of the expansion valve in the embodiment. FIG. 5 is a view for explaining the action of a groove for storing a brazing filler metal of the expansion valve in the embodiment, and FIG. . The subscripts of the reference numerals of the expansion valves 10 ₁ and 10 ₂ distinguish the first expansion valve and the second expansion valve. Omitted.

  As shown in FIGS. 1 and 2, the expansion valve 10 includes a valve housing 1. The valve housing 1 includes a main body 1 a that forms a cylindrical cylinder-shaped main valve chamber 1 </ b> A, and a lower portion from the lower end of the main body 1 a. It has the cylindrical part 1b extended to. A joint pipe 11 is attached to the valve housing 1 on the inner peripheral surface on one side of the main valve chamber 1A, and the end of the joint pipe 11 serves as a first port 11a that opens to the main valve chamber 1A. Further, a stainless steel valve seat ring 3 is press-fitted and attached to the main valve chamber 1A side in the tubular portion 1b, and a joint pipe 12 is attached to the lower end portion of the tubular portion 1b. The inside of the valve seat ring 3 is a second port 3a. A groove 33 for accumulating the molten brazing material is formed at the end of the valve seat ring 3 on the side of the joint pipe 12. In addition, a groove 32 is formed in addition to the groove 33 over the entire circumference of the inner peripheral surface at a location adjacent to the joint pipe 12 on the inner peripheral surface of the second port 3a.

  A sub valve 2 is disposed in the main valve chamber 1A. As shown in FIG. 5, the sub-valve 2 includes a guide member 21 and a valve seat member 22. The guide member 21 includes a disk portion 21a and three guide plates 211, 212, and 213. The valve seat member 22 is fixed to the center of the disk portion 21a, and a valve port 22a is formed at the center of the valve seat member 22.

  A support member 4 is fixed to the upper portion of the valve housing 1 by a fixing bracket 41. A long guide hole 42 is formed in the support member 4 in the direction of the axis L, and a pressure equalizing hole 43 communicating with the guide hole 42 is formed. Further, a pressure equalizing hole 44 is formed in the fixing bracket 41. A cylindrical valve holder 5 is inserted into the guide hole 42 so as to be slidable in the direction of the axis L. Thereby, the valve holder 5 is supported via the support member 4 so as to be movable in the direction of the axis L with respect to the valve housing 1.

  The valve holder 5 is attached coaxially to the main valve chamber 1A, and a stainless steel valve body 51 having a needle-like end is fixed to the lower end portion of the valve holder 5. The valve body 51 moves in the direction of the axis L together with the valve holder 5 to increase or decrease the opening area of the valve port 22a and control the flow rate of the fluid flowing from the first port 11a to the second port 3a to throttle the refrigerant. Fulfill. In addition, the valve body 51 is movable between a fully closed position that is lowered as shown in FIG. 1 and a fully opened position that is raised as shown in FIG.

  The valve holder 5 is engaged with the rotor shaft 61 of the stepping motor 6. That is, a flange portion 61 a is integrally formed at the lower end portion of the rotor shaft 61, and the flange portion 61 a sandwiches the washer 52 together with the upper end portion of the valve holder 5, and the lower end portion of the rotor shaft 61 is the upper end portion of the valve holder 5. It is rotatably engaged. By this engagement, the valve holder 5 is supported in a state of being rotatably suspended by the rotor shaft 61. A spring receiver 53 is provided in the valve holder 5 so as to be movable in the direction of the axis L, and a compression coil spring 54 is attached between the spring receiver 53 and the valve body 51 with a predetermined load applied. ing. As a result, the spring receiver 53 is biased upward and is in contact with and engaged with the lower end portion of the rotor shaft 61.

  The rotor shaft 61 is formed with a male screw portion 61 b, and the male screw portion 61 b is screwed into a female screw portion 4 a formed on the support member 4. As a result, the rotor shaft 61 moves in the direction of the axis L along with the rotation.

  A case 62 of the stepping motor 6 is airtightly fixed to the upper end of the valve housing 1 by welding or the like. In the case 62, a magnet rotor 63 whose outer periphery is magnetized in multiple poles is rotatably provided, and a rotor shaft 61 is fixed to the magnet rotor 63. A rotation stopper mechanism 64 that restricts the rotation of the magnet rotor 63 is provided on the ceiling of the case 62.

  A stator coil 65 is disposed on the outer periphery of the case 62, and the stepping motor 6 rotates the magnet rotor 63 according to the number of pulses when a pulse signal is given to the stator coil 65. Then, the rotor shaft 61 integral with the magnet rotor 63 is rotated by the rotation of the magnet rotor 63, and the valve body 51 is moved in the axis L direction together with the valve holder 5 by the movement of the rotor shaft 61 in the axis L direction accompanying the rotation.

  With the above configuration, the expansion valve 10 of the embodiment operates as follows. FIG. 1 shows a state in which high-pressure refrigerant is introduced from the joint pipe 11 (first port 11a) side, the refrigerant flow rate is controlled, and the expanded refrigerant flows out from the joint pipe 12 (second port 3a of the valve seat ring 3). Is shown. In this case, since the inside of the first port 11a and the main valve chamber 1A is high pressure and the second port 3a side is low pressure, the sub valve 2 is connected to the sub valve seat 31 around the second port 3a due to the differential pressure of the refrigerant pressure. Sit down and close the second port 3a. Then, by controlling the position of the valve body 51 in the axis L direction by the stepping motor 6, the flow rate of the refrigerant flowing from the main valve chamber 1A through the valve body 51 and the valve port 22a is controlled.

  On the other hand, the compressor 50 is stopped and the flow path switching valve 40 is switched. At this time, it is controlled by the stepping motor 6, the valve body 51 is moved in the direction (upward) away from the sub-valve 2, and the compressor 50 is driven again. Accordingly, when the high pressure refrigerant flows in from the joint pipe 12 (second port 3a) side and the refrigerant flows out from the joint pipe 11 (first port 11a), the second port 3a is at a high pressure and the main valve chamber 1A. And the 1st port 11a side becomes a low voltage | pressure. Then, the sub valve 2 is separated from the sub valve seat 31 by the differential pressure of the refrigerant pressure, and the state shown in FIG. That is, the second port 3a is fully opened. As a result, the refrigerant is released and circulated to the first port 11a via the second port 3a and the main valve chamber 1A.

  Next, details of the auxiliary valve 2 will be described. As shown in FIG. 4, the guide member 21 of the auxiliary valve 2 is formed by pressing a stainless steel plate, and includes a disk portion 21a that intersects the axis L of the main valve chamber 1A at a right angle, and the periphery of the disk portion 21a. Three guide plates 211, 212, and 213 provided upright at three locations are integrally formed. Each guide plate 211, 212, 213 has a flat plate shape (flat), and is erected in an L shape in a direction parallel to the axis L with respect to the disk portion 21a. A substantially circular fitting hole 21b is formed at the center of the disk portion 21a.

  When the guide member 21 is pressed, the pressing is performed twice, and the portions of the guide plates 211, 212, and 213 are pressed from the direction of the arrow P1 shown in FIG. Further, the end portions of the disk portion 21a other than the guide plates 211, 212, and 213 are pressed from the direction of the arrow P2 shown in FIG.

  The valve seat member 22 of the sub-valve 2 is formed by cutting stainless steel, and has a frustoconical sub-valve portion 221 at the bottom and a disc-shaped flange portion 222 formed on the outer periphery of the sub-valve portion 221. The annular annular boss portion 223 formed on the upper portion is integrally formed. The annular boss 223 is formed so as to become thinner toward the end.

  With the above configuration, the auxiliary valve 2 is assembled as follows. The annular boss portion 223 of the valve seat member 22 is inserted into the fitting hole 21b of the guide member 21, and the end portion of the annular boss portion 223 is widened to the outer peripheral side with the flange portion 222 abutting against the back surface of the disk portion 21a. Caulking like so. Thereby, the guide member 21 and the valve seat member 22 are combined. Then, spot welding is performed on a joint portion (joint portion indicated by an arc-like broken line in FIG. 5A) between the end portion of the disc portion 21a of the guide member 21 and the end portion of the flange portion 222 of the valve seat member 22.

  When the guide member 21 and the valve seat member 22 are coupled only by caulking, the guide member 21 falls off the valve seat member 22 if the annular boss portion 223 is not caulked. Conversely, if the caulking is too strong, the guide member 21 is deformed and a predetermined clearance from the valve housing cannot be secured. As a result, in the worst case, the secondary valve 2 may be locked in the valve housing 1. Further, when the guide member 21 and the valve seat member 22 are coupled only by spot welding, it is difficult to hold the valve seat member 22 at the center of the guide member 21 due to the clearance between the guide member 21 and the valve seat member 22. It is. Therefore, after the guide member 21 is centered with respect to the valve seat member 22 by caulking the annular boss portion 223 as described above, the guide member 21 and the valve seat member 22 are securely fixed by spot welding. In addition, the valve seat member 22 can be held at the center of the guide member 21.

  In addition, although the sagging surface and the burr | flash at the time of a press are formed in the edge part of the disk part 21a, since it presses from the direction of arrow P2 as mentioned above, the sagging surface is the flange part 222 of the valve seat member 22. The burr can be on the flange 222 side. The disk portion 21a is formed to have a diameter slightly larger than that of the flange portion 222, and the burr portion is melted at the time of spot welding by taking the burr out of the flange portion 222. Thereby, the disk part 21a and the flange part 222 can be closely_contact | adhered without gap, and spot welding can be performed more reliably.

  The guide plates 211, 212, 213 of the auxiliary valve 2 are flat (flat), and the edges of both ends parallel to the axis L of each guide plate 211, 212, 213 are the inner peripheral surface 1a1 of the main body 1a (FIG. 5 ( A) is slidable in line contact with respect to the reference), and can slide in the direction of the axis L in the main valve chamber 1A. Further, since the guide plates 211, 212, and 213 are flat, a gap is formed between the guide plates 211, 212, and 213 and the inner peripheral surface 1a1, and the guide plates 211, 212, and 213 and the inner peripheral surface 1a1 are formed. The sub-valve 2 can be operated in a stable manner without causing dust or the like to bite between them.

  Further, when the guide member 21 of the sub-valve 2 is pressed, the portions of the guide plates 211, 212, and 213 are pressed from the direction of the arrow P1 shown in FIG. The contacting part becomes a sag surface. Therefore, the sliding operation of the auxiliary valve 2 can be made stable.

  In the auxiliary valve 2, since the guide member 21 is a lightweight member formed of a thin plate-like stainless steel plate, for example, the entire auxiliary valve (valve seat member 2) of Patent Document 1 is formed by cutting. In comparison, the weight can be reduced, and when the state shown in FIG. 1 is shifted to the state shown in FIG. 2, the auxiliary valve 2 is easily lifted and a stable operation can be obtained. Further, since the valve seat member 22 is formed by cutting, the valve port 22a can be formed with high accuracy, and a highly reliable expansion valve can be obtained by preventing valve leakage.

  As shown in FIG. 3A, the following steps are performed when the expansion valve is assembled. The valve seat ring 3 is press-fitted into the tubular portion 1b of the valve housing 1 from the inside, and the joint pipe 12 is inserted into the tubular portion 1b with the ring-shaped brazing material a fitted into the joint pipe 12. Is done. At this time, the end of the joint pipe 12 is abutted against the valve seat ring 3. The joint pipe 11 is also inserted into the main body 1a with the same brazing material b fitted therein. And the joint pipe | tubes 11 and 12 are brazed with respect to the valve housing 1 by heating the assembly assembled | attached as shown in FIG.3 (B) in the flux furnace of a brazing apparatus.

  Here, depending on the atmospheric conditions of the brazing device, it may be difficult to control the flow rate of the molten brazing material, and the brazing material may flow out to the second port 3 a side of the valve seat ring 3. However, as shown in FIG. 4B, even if the molten brazing material flows out to the second port 3a side, a groove 33 is formed in the inner periphery of the joint pipe 12 side in the second port 3a of the valve seat ring 3. Therefore, the brazing material that has flowed out from the periphery of the joint pipe 12 to the valve seat ring 3 side accumulates in the groove 33 and does not reach the valve seat 31. 4A is an enlarged view of the periphery of the valve seat ring 3, and FIG. 4C is a case where the brazing material further flows out to the second port 3a side from the state of FIG. 4B. The brazing material collects in the groove 32 provided in addition to the groove 33 in the second port 3a. Thus, if a plurality of grooves for storing the molten brazing material are provided, it is possible to more reliably prevent the molten brazing material from reaching the valve seat 31.

In the above embodiment, the case where the second port is formed on the valve seat ring has been described. However, as a reference example, even when the valve seat ring is not provided and the second port is formed directly on the valve housing, A groove may be formed in the second port.

In the embodiment, the case where the two grooves 32 and 33 are formed has been described. However, in the case of the valve seat ring, in any case of the valve housing of the reference example, three or more grooves are formed. It goes without saying.

DESCRIPTION OF SYMBOLS 1 Valve housing 1A Main valve chamber 1a Body part 1b Tubular part 11 Joint pipe 11a 1st port 12 Joint pipe 2 Sub valve 21 Guide member 22 Valve seat member 211,212,213 Guide plate 22a Valve port 22a
221 Sub valve portion 3 Valve seat ring 3a Second port 31 Sub valve seat 32 Groove 33 Groove 5 Valve holder 51 Valve body 6 Stepping motor L shaft

Claims (1)

A valve housing constituting a cylindrical main valve chamber; a first port communicating with the main valve chamber; a second port communicating with an axial end of the main valve chamber; and the main valve chamber within the main valve chamber An auxiliary valve having a valve port between the main valve chamber and the second port, and a valve element that opens and closes the valve port by the axial movement relative to the auxiliary valve; With
When the refrigerant flows from the first port to the second port, the sub-valve is seated on the sub-valve seat around the second port by the differential pressure between the first port and the second port, and the second port is In the closed state, when the refrigerant flowing to the valve port is throttled by the valve body and the refrigerant is allowed to flow in the reverse direction, the sub-valve is separated from the second port by the differential pressure between the second port and the first port. In the expansion valve in which the second port is fully opened,
An inner diameter of the second port and a joint pipe communicating with the second port is the same, and an inner side of a valve seat ring having the same diameter as the joint pipe is the second port, and the valve housing Rutotomoni fitted with seat rings together butted and the the valve seat ring the joint pipe and the main valve chamber side, is configured to be the valve housing and brazed with該継hand at the periphery of該継Tekuda ,
An open end of the second port said joint pipe side there all around the inner peripheral surface at a location adjacent to the joint pipe inner peripheral surface of the second port, to the interior of the second port, An expansion valve characterized by forming a plurality of grooves for storing molten brazing filler metal.

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