JP2013164125A - Expansion valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the weight of a sub-valve and enhance the accuracy of a valve port, in an expansion valve which performs a function of throttling a refrigerant in a first flow direction of the refrigerant by moving the sub-valve in a valve housing, and releases the refrigerant to flow in a second flow direction.SOLUTION: A sub-valve 2 includes: a guide member 21 formed by press working; and a valve seat member 22 formed by cutting work. When a main valve chamber 1A is under high pressure, the sub-valve 2 is seated in a sub-valve seat 31 of a valve seat ring 3. When the main valve chamber 1A is in low pressure, the sub-valve 2 is separated from the sub-valve seat 31 of the valve seat ring 3. The sub-valve 2 is lightened by forming the guide member 21 in press working and the accuracy of a valve port 22a is enhanced by forming the valve seat member 22 by cutting.

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, a throttle function including flow rate control is performed on the indoor heat exchanger side in the cooling mode, and outdoor heat exchange is performed in the heating mode. There has been proposed an expansion valve that can perform a throttle function on the vessel side.

JP 2009-287913 A

  The expansion valve of Patent Document 1 functions to throttle the refrigerant with respect to the first flow direction of the refrigerant, and to reduce the pressure loss with respect to the second flow direction as much as possible to flow a large flow rate. A valve seat member (2, 8) is provided as a valve, and the valve seat member (2, 8) is slid in the axial direction within the valve housing (1, 7).

  However, in the expansion valve of Patent Document 1, the valve seat member (2) is a thick member, and the valve seat member (2) itself becomes heavy and operates when it is separated from the second port (12). There is a problem that it is difficult. On the other hand, since the valve seat member (8) is formed by pressing, the valve seat member (8) is light in weight and easily operates when separated from the second port (72). However, since this valve seat member (8) is also formed by pressing the valve port (81a), it is difficult to obtain accuracy in the diameter and shape of the valve port (81a). There is a problem that valve leakage is likely to occur.

  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. It is an object of the present invention to reduce the weight of a subvalve and to increase the accuracy of the valve port of the subvalve in an expansion valve in which a loss can be minimized and a large flow rate can flow.

  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 seated around the second port due to a differential pressure between the first port and the second port. When the second port is closed, the refrigerant flowing to the valve port is throttled by the valve body, and when the refrigerant flows in the reverse direction, the sub-valve is controlled by the differential pressure between the second port and the first port. Keep away from the second port and fully open the second port In the expansion valve, the sub-valve is a guide member that is slidably contacted with the inner peripheral surface of the valve housing and is formed by pressing a metal plate, and has the valve port and is arranged at the center of the guide member The valve seat member is a valve seat member formed by cutting a metal material.

  An expansion valve according to a second aspect is the expansion valve according to the first aspect, wherein the guide member includes a disk portion perpendicular to the axis of the main valve chamber and a fitting formed at the center of the disk portion. The valve seat member has a disc-shaped flange portion and an annular annular boss portion formed on the upper portion of the flange portion. And the annular boss portion of the valve seat member is inserted into the fitting hole of the guide member, and the flange portion and the The disk part is closely bonded, and spot welding is applied to the joint part between the end part of the disk part and the end part of the flange part, and the guide member and the valve seat member are fixed to each other. It is characterized by that.

  An expansion valve according to a third aspect is the expansion valve according to the second aspect, wherein burrs are formed on the side edges of the guide plate parallel to the axial direction by pressing, and the spot welding is performed. A sag surface is formed by pressing at the edge of the disk portion opposite to the flange portion.

  According to the expansion valve of the first aspect, in the auxiliary valve, the guide member is formed by pressing a metal disc, so that the auxiliary valve itself can be reduced in weight, and the valve seat member is formed by cutting. Therefore, the valve port can be formed with high accuracy, and a highly reliable expansion valve can be obtained by preventing valve leakage.

  According to the expansion valve of the second aspect, in addition to the effect of the first aspect, in the auxiliary valve, the guide member and the valve seat member can be firmly coupled by caulking and spot welding.

  According to the expansion valve of the third aspect, in addition to the effect of the second aspect, since there is no burr of press working at the contact portion of the side edge of the guide plate that makes line contact with the inner peripheral surface of the valve housing, the auxiliary valve is easy Stable operation can be obtained. In addition, the sag surface of the disk part is on the opposite side of the flange part, that is, in the state before spot welding, the burrs of the press work in the disk part are on the flange part side so that this burr comes outside the flange part. In this case, this burr is melted during spot welding. Thereby, since a disk part and a flange part closely_contact | adhere without gap, spot welding can be performed more reliably.

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 the top view and longitudinal cross-sectional view of a subvalve in embodiment of this invention. It is a perspective view before the assembly of the guide member and valve seat member of the sub valve in the embodiment of the present invention. It is a perspective view of the assembly state of the subvalve in the embodiment of the present invention. It is a figure which shows the other example of the 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. 7 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. 7, 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 respectively 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 throttled state in which the refrigerant flow rate is controlled. 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 plan view of the auxiliary valve in the embodiment (FIG. FIG. 3 is a perspective view of the auxiliary valve guide member and the valve seat member before assembly, and FIG. 5 is an assembled perspective view of the auxiliary valve. 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 attached to the main valve chamber 1A side in the tubular portion 1b, and a joint pipe 12 is attached to a lower end portion of the tubular portion 1b. The inside of the valve seat ring 3 is a second port 3a.

  A sub valve 2 is disposed in the main valve chamber 1A. As shown in FIG. 3, the auxiliary 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 FIGS. Moreover, the part of the edge part of the disc part 21a other than the guide plates 211, 212, and 213 is 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-shaped broken line in FIG. 3A) 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, as shown in the enlarged sectional view surrounded by a two-dot chain line circle in FIG. 4, a sag surface and a burr at the time of pressing are formed at the end of the disk portion 21a. Since pressing is performed from the direction, the sagging surface can be on the side opposite to the flange portion 222 of the valve seat member 22 and the burr can be on the flange portion 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, and 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, and 213 are the inner peripheral surface 1a1 (FIG. A) is slidable in line contact with respect to the reference) and is slidable 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.

  Furthermore, 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. Becomes sagging. 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.

  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 a ring-shaped brazing material is fitted into the joint pipe 12 with respect to the tubular portion 1b. In this state, the joint pipe 12 is inserted. The joint pipe 11 is also inserted into the main body 1a with a similar brazing material fitted therein. And the joint pipes 11 and 12 are brazed with respect to the valve housing 1 by heating the assembled assembly 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 amount of the molten brazing material flowing, and when the brazing material flows out to the secondary valve seat through the second port of the valve seat ring, Since the brazing material adheres to the contact surface between the valve seat ring and the sub-valve and makes the shape non-uniform, there is a risk of valve leakage. However, the valve seat ring 3 of this embodiment has a groove 32 formed on the inner periphery of the second port 3a on the side of the joint pipe 12. Accordingly, the brazing material that has flowed out from the periphery of the joint pipe 12 toward the valve seat ring 3 is accumulated in the groove 32 and does not reach the valve seat 31.

  In the above embodiment, the auxiliary valve 2 has been described with respect to the case where the guide plates 211, 212, and 213 have a flat plate shape. However, as shown in FIG. 6 (A), the curved guide plate 711 that is curved inward. A secondary valve 2 ′ having 712 and 713 may be used. In FIG. 6, the same or corresponding elements as those in the embodiment (FIG. 3) are denoted by the same reference numerals, and the description thereof is omitted. The guide plates 711, 712, and 713 are curved in the direction opposite to the inner peripheral surface 1a1 of the valve housing 1. In this way, it is sufficient if there are gaps between the inner peripheral surface 1a1 of the main body 1a and the guide plates 711, 712, 713. Also in this case, the burr | flash by press work is formed inside.

  In the above embodiment, the sub-valve 2 and 2 ′ have been described with respect to the case where there are three guide plates. However, as shown in FIG. 6 (B), four guide plates 811, 812, 813 and 814 are used. The number of guide plates may be three or four. As the number of guide plates increases, the gap between the main body 1a and the inner peripheral surface 1a1 becomes narrower, and dust is generated. There is also a high possibility of biting, and there is also a problem of interference with the joint pipe 11. These four guide plates are also in the opposite direction to the inner peripheral surface 1a1 of the valve housing 1 as shown in FIG. In this case as well, the burr formed by pressing is formed inside.

DESCRIPTION OF SYMBOLS 1 Valve housing 1A Main valve chamber 1a Main-body part 1a1 Inner peripheral surface 1b Tubular part 11 Joint pipe 11a 1st port 12 Joint pipe 2 Subvalve 21 Guide member 22 Valve seat member 21a Disk part 21b Fitting hole 211,212,213 Guide plate 22a Valve port 22a
221 Sub valve portion 222 Flange portion 223 Annular boss portion 3 Valve seat ring 3a Second port 31 Sub valve seat 5 Valve holder 51 Valve body 6 Stepping motor L shaft

Claims (3)

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 around the second port by the pressure difference between the first port and the second port to close the second port. In addition, when the refrigerant flowing to the valve port is throttled by the valve body and the refrigerant flows in the reverse direction, the second 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 port is fully open,
A guide member that is slidably in contact with the inner peripheral surface of the valve housing, the sub-valve being formed by pressing a metal plate, and a valve seat that has the valve port and is arranged at the center of the guide member An expansion valve characterized by comprising a member and a valve seat member formed by cutting a metal material. The guide member includes a disk portion that intersects the axis of the main valve chamber at a right angle, a fitting hole formed in the center of the disk portion, and a plurality of guide plates provided upright around the disk portion. And
The valve seat member has a disk-shaped flange portion and an annular annular boss portion formed on the upper portion of the flange portion,
An annular boss portion of the valve seat member is inserted into a fitting hole of the guide member, and the flange portion and the disc portion are in close contact with each other by caulking the end portion of the annular boss portion so as to spread outward. And spot welding is applied to the joint portion between the end portion of the disk portion and the end portion of the flange portion, and the guide member and the valve seat member are fixed to each other. The expansion valve according to claim 1.   A burr formed by pressing at a side edge parallel to the axial direction of the guide plate is formed on the inner side, and the edge opposite to the flange portion of the disk portion at the spot-welded portion is formed by pressing. The expansion valve according to claim 2, wherein a sag surface is provided.

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