JP2019023484A - Motor valve and refrigeration cycle system - Google Patents

Abstract

To reduce noise caused by flow of a fluid in an electric valve which opens or closes a valve port 11 with a needle valve 6 to control a flow rate of the fluid such as a refrigerant.SOLUTION: A valve port 11, a taper part 12, and a straight part 13 are formed at a valve housing 1. The taper part 12 and the straight part 13 form an expansion space 1B. A nozzle part 2 is provided at a valve housing 1 side end part of a secondary joint 31. A cylinder part 22 of the nozzle part 2 protrudes into the expansion space 1B and an accumulation space 1C is formed between the cylinder part 22 and the straight part 13. A fluid is accumulated in the accumulation space 1C to increase a loss coefficient of a pressure of the fluid. The nozzle part 2 may be formed separately from the secondary joint 31.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor-operated valve that controls the flow rate of refrigerant in an air conditioner or the like, and more particularly to a motor-operated valve and a refrigeration cycle system having an improved shape around a valve port.

  Conventionally, in a refrigeration cycle system, noise accompanying the passage of refrigerant, which is generated from an electric valve that controls the flow rate of the refrigerant, often becomes a problem. For example, Japanese Patent Application Laid-Open No. 2012-82896 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2007-107847 (Patent Document 2) have disclosed motor-driven valves that take such noise countermeasures.

  The electric valve of Patent Document 1 causes the refrigerant to flow out into the second valve port having a larger inner diameter than the first valve port, and reduces the flow velocity in the second valve port (enlarged space) before reaching the secondary joint pipe. Noise. Moreover, the electric valve of patent document 2 is changing the shape of a secondary joint pipe (outlet joint pipe), improving the natural frequency, and aiming at noise reduction.

JP 2012-82896 A JP 2007-107847 A

  In the electric valve of Patent Document 1, the flow rate of the refrigerant in the second port, which is an expansion space with respect to the first port, is fast, and there is room for improvement in order to reduce noise. In the electric valve of Patent Document 2, it is extremely difficult to set the natural frequency of the secondary joint pipe corresponding to noise.

  The present invention allows a fluid such as a refrigerant to flow into the valve chamber from the primary joint pipe, allows the fluid to flow into the expansion space from between the needle valve and the valve port, and sets the speed of the fluid flowing out to the secondary joint pipe. It is another object of the present invention to provide a motor-operated valve that is further decelerated to further reduce noise such as fluid passing sound with respect to the fluid flow.

  The motor-operated valve according to claim 1 is a motor-operated valve that enables communication between a valve chamber that communicates with a primary joint pipe and a secondary joint pipe via a valve port whose opening area is increased or decreased by a needle valve, In the electric valve having an expansion space whose diameter is larger than that of the valve port on the secondary joint pipe side of the valve port, the expansion space communicates with the pipe line of the secondary joint pipe, and the expansion space The nozzle part which protrudes inward and forms the retention space in which a fluid retains between the inner walls of this expansion space is provided.

  A motor-driven valve according to a second aspect is the motor-operated valve according to the first aspect, wherein an inner diameter of the nozzle portion is larger than an inner diameter of the valve port.

  The motor-driven valve according to claim 3 is the motor-operated valve according to claim 1 or 2, wherein the expansion space includes a tapered portion having a truncated cone side shape on the valve port side and the secondary joint pipe from the tapered portion. It is formed by the straight part of the cylindrical side surface shape extended to the side.

  The motor-operated valve according to claim 4 is the motor-operated valve according to any one of claims 1 to 3, wherein the nozzle portion is formed integrally with an end portion of the secondary joint pipe. To do.

  The refrigeration cycle system according to claim 5 is a refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the electric valve according to any one of claims 1 to 4 is provided. It is used as the expansion valve.

  According to the electric valve of the first to fourth aspects, when the fluid flowing from the gap between the valve port and the needle valve flows out into the expansion space, the fluid stays in the retention space formed by the nozzle portion in the expansion space. The loss factor of the pressure of the fluid flowing from the nozzle portion to the secondary joint pipe can be increased to suppress the flow velocity, and noise can be reduced.

  According to the electric valve of the second aspect, since the inner diameter of the nozzle portion is larger than the inner diameter of the valve port, it is possible to ensure the flow rate flowing through the secondary joint pipe when the valve port is fully opened.

  According to the motor-driven valve of the third aspect, since the enlarged space is formed by the tapered portion and the straight portion, the staying space can be secured by the tapered portion.

  According to the electric valve of the fourth aspect, since the nozzle portion is formed integrally with the end portion of the secondary joint pipe, the electric valve can be easily assembled and the number of parts can be reduced.

  According to the refrigeration cycle system of claim 5, the same effects as in claims 1 to 4 can be obtained.

It is a longitudinal cross-sectional view of the motor operated valve of embodiment of this invention. It is a principal part expansion longitudinal cross-sectional view of the valve port vicinity in the motor operated valve of embodiment of this invention. It is a figure explaining the effect | action of the valve port in the motor operated valve of embodiment of this invention. It is a figure which shows an example of the air conditioner using the motor operated valve of embodiment of this invention. It is a figure which shows the 1st modification thru | or 3rd modification of embodiment of this invention.

  Next, an embodiment of the motor-operated valve of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal sectional view of a motor-operated valve according to the embodiment, FIG. 2 is an enlarged longitudinal sectional view of a main part in the vicinity of the valve port in the motor-operated valve according to the embodiment, and FIG. FIG. 4 is a diagram illustrating an example of an air conditioner using the electric valve of the embodiment. Note that the concept of “upper and lower” in the following description corresponds to the upper and lower sides in the drawing of FIG.

  First, the air conditioner according to the embodiment will be described with reference to FIG. The air conditioner includes an electric valve 10 as an expansion valve, an outdoor heat exchanger 20 mounted on the outdoor unit 100, an indoor heat exchanger 30 mounted on the indoor unit 200, a flow path switching valve 40, and a compressor. Each of these elements is connected by a conduit as shown in the figure to constitute a heat pump type refrigeration cycle system. This refrigeration cycle system is an example of a refrigeration cycle system to which the electric valve of the present invention is applied, and the electric valve of the present invention is also applied to other systems such as a throttle device on the indoor unit side such as a multi air conditioner for buildings. be able to.

  The flow path of the refrigeration cycle system is switched to the two flow paths of the heating mode and the cooling mode by the flow path switching valve 40, and in the heating mode, as indicated by the solid line arrow, the refrigerant as the fluid compressed by the compressor 50 Flows into the indoor heat exchanger 30 from the flow path switching valve 40, and the refrigerant flowing out of the indoor heat exchanger 30 flows into the motor-operated valve 10 through the pipe line 60. Then, the refrigerant is expanded by the electric valve 10 and circulated in the order of the outdoor heat exchanger 20, the flow path switching valve 40, and the compressor 50. 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 and the refrigerant flowing out of the outdoor heat exchanger 20 flows through the motor operated valve 10 as indicated by the dashed arrows. It is expanded, flows through the pipe line 60 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 example shown in FIG. 4, the refrigerant is configured to flow from the primary joint pipe 31 to the secondary joint pipe 32 in the heating valve in the heating mode. The refrigerant may flow from the secondary joint pipe 32 to the primary joint pipe 31.

  The motor-operated valve 10 functions as an expansion valve (throttle device) that controls the flow rate of the refrigerant. In the heating mode, the outdoor heat exchanger 20 functions as an evaporator, the indoor heat exchanger 30 functions as a condenser, Heating is done. In the cooling mode, the outdoor heat exchanger 20 functions as a condenser, the indoor heat exchanger 30 functions as an evaporator, and the room is cooled.

  Next, based on FIG.1 and FIG.2, the motor operated valve 10 of embodiment is demonstrated. The electric valve 10 has a valve housing 1 formed by cutting a metal member such as stainless steel or brass, and the valve housing 1 is formed with a valve chamber 1A. Further, the valve housing 1 is formed with a valve port 11 that opens to the valve chamber 1 </ b> A, a tapered portion 12, and a straight portion 13. The valve port 11, the tapered portion 12 and the straight portion 13 have an axis X as the central axis, the valve port 11 has a thin cylindrical shape, the tapered portion 12 has a truncated cone side shape, and the straight portion 13 has a cylindrical shape.

  In addition, a primary joint pipe 31 that communicates with the valve chamber 1 </ b> A from the side surface side is attached to the valve housing 1, and a secondary joint pipe 32 is attached to one end of the straight portion 13 in the axis X direction. The tapered portion 12 continues from the lower end of the valve port 11 to the upper end of the straight portion 13, and the straight portion 13 extends to the secondary joint pipe 32 side. The valve chamber 1 </ b> A and the secondary joint pipe 32 can be electrically connected to each other through the valve port 11, the tapered portion 12, and the straight portion 13.

  Further, a valve guide member 33 is attached to the valve housing 1 by press-fitting and caulking so as to be inserted into the valve chamber 1A from above, and a valve guide hole 33a is formed at the center of the valve guide member 33. ing. A rim 1a is formed at the upper end of the valve housing 1 so as to surround the outer periphery of the upper end of the valve guide member 33. The valve housing 1 has a cylindrical case so as to be fitted to the outer periphery of the rim 1a. 34 is assembled. The case 34 is fixed to the valve housing 1 by caulking the rim 1a and brazing the outer periphery of the bottom. Further, the support member 4 is attached to the upper end opening of the case 34 via a fixing bracket 41.

  In the center of the support member 4, a female screw portion 4a coaxial with the axis X of the valve port 11 and a screw hole thereof are formed, and a cylindrical slide hole 4b having a diameter larger than the outer periphery of the screw hole of the female screw portion 4a is formed. Is formed. A cylindrical rod-shaped rotor shaft 72 described later is disposed in the screw hole and the slide hole 4a of the female screw portion 4a. A valve holder 5 is fitted in the slide hole 4b so as to be slidable in the direction of the axis X. The valve holder 5 is connected to the rotor shaft 72 at the upper part and holds the needle valve 6 at the lower part. Yes.

  The valve holder 5 has a boss portion 52 fixed to the lower end of a cylindrical cylindrical portion 51, and includes a spring receiver 53, a compression coil spring 54, a washer 55, and a spacer 56 in the cylindrical portion 51. The needle valve 6 is formed of a metal member such as stainless steel or brass, and has a substantially elliptical needle portion 6a at the lower end, a cylindrical rod-shaped rod portion 6b, and an upper flange portion 6c. The needle valve 6 is inserted into the insertion hole 52 a of the boss portion 52 of the valve holder 5 and attached to the valve holder 5 with the flange portion 6 c abutting against the boss portion 52. The rod portion 6 b of the needle valve 6 is inserted into the valve guide hole 33 a of the valve guide member 33.

  In the valve holder 5, the compression coil spring 54 is attached between the spring receiver 53 and the flange portion 6 c of the needle valve 6 in a state where a predetermined load is applied. The valve holder 5 attaches the spring receiver 53 to the spacer 56. The upper end portion of the spacer 56 is pressed by the upper end portion of the cylindrical portion 51 via the washer 55. The flange portion 72 b of the rotor shaft 72 is engaged between the washer 55 and the spacer 56, and is prevented from coming off by the washer 55. Thus, the needle valve 6 is connected to the rotor shaft 72 via the valve holder 5 and is movable in the direction of the axis X while being guided by the rod portion 6b.

  A sealed case 35 is airtightly fixed to the upper end of the case 34 by welding or the like. In the sealed case 35, there are provided a magnet rotor 71 whose outer peripheral portion is magnetized in multiple poles and the rotor shaft 72 fixed to the center of the magnet rotor 71. The upper end portion of the rotor shaft 72 is rotatably fitted in a cylindrical guide 36 provided on the ceiling portion of the sealed case 35. The rotor shaft 72 has a male screw portion 72 a, and the male screw portion 72 a is screwed into the female screw portion 4 a formed on the support member 4. A stator coil 73 is disposed on the outer periphery of the hermetic case 35, and the magnet rotor 71, the rotor shaft 72, and the stator coil 73 constitute a stepping motor 7. When a pulse signal is applied to the stator coil 73, the magnet rotor 71 is rotated according to the number of pulses, and the rotor shaft 72 is rotated. A rotation stopper mechanism 37 for the magnet rotor 71 is provided on the outer periphery of the guide 36.

  With the above configuration, the motor-operated valve of the embodiment operates as follows. First, in the state of FIG. 1, the magnet rotor 71 and the rotor shaft 72 are rotated by driving the stepping motor 7, and the rotor shaft is rotated by the screw feed mechanism between the male screw portion 72 a of the rotor shaft 72 and the female screw portion 4 a of the support member 4. 72 moves in the direction of the axis X. The needle valve 6 moves in the axis X direction together with the valve holder 5 by the movement in the axis X direction of the rotor shaft 72 accompanying this rotation. The needle valve 6 increases or decreases the opening area of the valve port 11 at the needle portion 6a, and fluid flows from the primary joint pipe 31 to the secondary joint pipe 32 or from the secondary joint pipe 32 to the primary joint pipe 31 ( The flow rate of the refrigerant is controlled.

  At the end of the secondary joint pipe 32 on the valve housing 1 side, a nozzle part 2 comprising a thick connecting pipe part 21 fitted into the valve housing 1 and a cylindrical tube part 22 is formed. The nozzle portion 2 is formed with a communication passage 23 that penetrates the connecting pipe portion 21 and the cylindrical portion 22. Here, the tapered portion 12 and the straight portion 13 on the valve housing 1 side constitute an enlarged space 1B having a diameter larger than that of the valve port 11, and the nozzle portion 2 is connected to the enlarged space 1B by the communication passage 23. The pipe line 32a of the next joint pipe 32 is communicated. The cylindrical portion 22 of the nozzle portion 2 is disposed so as to protrude toward the valve port 11 in the enlarged space 1B (in the straight portion 13), and the outer peripheral surface of the cylindrical portion 22 and the inner wall of the enlarged space 1B (in the straight portion 13). A stay space 1C, which is an annular space, is formed between the inner wall and the inner wall. A part of the fluid flowing out from the valve port 11 is retained in the retention space 1C.

The dimensions of each part in the embodiment are set so as to satisfy the following conditions. As shown in FIG. 2, the inner diameter of the valve port 11 is a dimension matched to the outer periphery of the needle portion 6a. The inner diameter of the communication passage 23 of the nozzle portion 2 is larger than the inner diameter of the valve port 11. For the total length L1 of the valve port 11, the taper portion 12 and the straight portion 13, the length L2 of the needle portion 6a (the length within the valve seat of the needle portion when the valve port 11 is fully closed) is:
(L2) ≦ (L1) / 2
Are in a relationship.
The length L2 of the needle portion 6a and the length L3 of the cylindrical portion 22 are
(L2)>(L3)> (L2) / 5
Are in a relationship.
Further, the radial width W1 of the cylindrical portion 22 and the radial width W2 of the stay space 1C are as follows:
W2> W1
Are in a relationship. These dimensions and angles are not limited to those shown in FIG.

  With the above configuration, as shown in FIG. 3, when the fluid flows from the primary joint pipe 31 into the valve chamber 1 </ b> A and flows to the secondary joint pipe 32 side, the fluid passes through the gap between the needle portion 6 a and the valve port 11. The fluid flows through the tapered portion 12, the straight portion 13, and the communication passage 23 of the nozzle portion 2 to the secondary joint pipe 32. At this time, the gap between the needle portion 6a and the valve port 11 is the narrowest part, where the flow velocity is maximum, but the length of the valve port 11 is as short as possible, and the fluid flowing through this gap The flow follows the tapered portion 12. Since the enlarged space 1 </ b> B composed of the tapered portion 12 and the straight portion 13 is larger than the inner diameter of the valve port 11, the pressure is rapidly recovered at the tapered portion 12. A part of the fluid flows into the stay space 1C, and the fluid stays in the stay space 1C. Therefore, the flow velocity of the fluid flowing through the communication passage 23 of the nozzle unit 2 is reduced, and cavitation and flow can be prevented from coming into contact with the secondary joint pipe 32, and the flow of fluid can be stabilized and noise can be reduced. That is, by forming the staying space 1C by projecting the cylindrical tube portion 22 in the fluid flow path, the fluid pressure loss coefficient can be increased, the flow velocity can be suppressed, and noise can be reduced.

  FIG. 5 is a diagram illustrating first to third modifications of the nozzle unit 2. In the following modification, the same elements as those in the embodiment are denoted by the same reference numerals as those in FIGS. In the first modification of FIG. 5A, a cylindrical tube portion 22 'is formed in the connecting tube portion 21, and the end portion of the tube portion 22' is expanded outward. Further, in the second modified example of FIG. 5B, a cylindrical tube portion 22 ″ is formed in the connecting tube portion 21, and an end portion of the tube portion 22 ″ is reduced inward. However, the inner diameter of this reduced diameter portion is larger than the inner diameter of the valve port. In the first modification, the fluid hardly flows into the staying space 1C by the amount that the end portion of the cylindrical portion 22 'is expanded. Conversely, in the second modification example, the end portion of the cylindrical portion 22 "is expanded in diameter. The fluid easily flows in the staying space 1C as much as it is, that is, the amount of fluid to stay in the staying space 1C is adjusted by the shape of the end of the cylindrical portion as in the first and second modifications. can do.

  In the nozzle part 2 of the third modification of FIG. 5C, a cylindrical part 24 having a truncated cone shape is formed in the connecting pipe part 21, and the connecting pipe part 21 and the cylindrical part 24 pass through the nozzle part 2. A frustoconical (tapered) communication path 23 'is formed. However, the inner diameter of the upper surface of the truncated cone shape is larger than the inner diameter of the valve port. In this third modification, the pressure of the fluid flowing in the pipe line 32a of the secondary joint pipe 32 is recovered even in the communication path 23 ', and the flow velocity of the fluid is reduced.

  In the above embodiment and modification, although the case where the nozzle part 2 was formed integrally with the secondary joint pipe 32 was explained, the nozzle part is constituted by a separate member from the secondary joint pipe, and the secondary joint pipe and You may make it attach between valve housings. In the embodiment and the modification, the enlarged space 1B is configured by the tapered portion 12 and the straight portion 13, but the expanded space may be configured by only the tapered portion 12 or only the straight portion 13. Furthermore, the structure which provided the taper part and the straight part in multiple steps may be sufficient.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention.

DESCRIPTION OF SYMBOLS 1 Valve housing 1A Valve chamber 11 Valve port 12 Taper part 13 Straight part 1B Expansion space 1C Retention space 2 Nozzle part 21 Connection pipe part 22 Cylinder part 23 Communication path 22 'Cylinder part 22 "Cylinder part 23' Communication path 24 Cylinder part 31 Primary joint pipe 32 Secondary joint pipe 32a Pipe line 4 Support member 4a Female thread part 4b Slide hole 5 Valve holder 6 Needle valve 6a Needle part 7 Stepping motor 71 Magnet rotor 72 Rotor shaft 72a Male thread part 73 Stator coil X Axis 10 Electric valve 20 Outdoor heat exchanger 30 Indoor heat exchanger 40 Flow path switching valve 50 Compressor 100 Outdoor unit 200 Indoor unit

Claims (5)

An electric valve that enables communication between a valve chamber to which a primary joint pipe is communicated and a secondary joint pipe through a valve port whose opening area is increased or decreased by a needle valve, and the secondary joint pipe of the valve port On the side, in the electric valve having an enlarged space whose diameter is larger than that of the valve port,
A nozzle portion that communicates the expansion space and the pipe line of the secondary joint pipe, and that projects into the expansion space and forms a retention space in which fluid stays between the expansion wall and the inner wall of the expansion space; Features a motorized valve.   The motor operated valve according to claim 1, wherein an inner diameter of the nozzle portion is larger than an inner diameter of the valve port.   The expansion space is formed by a tapered portion having a side surface shape of a truncated cone on the valve port side, and a straight portion having a cylindrical side surface shape extending from the tapered portion toward the secondary joint pipe side. The motor-operated valve according to 1 or 2.   The motor-operated valve according to any one of claims 1 to 3, wherein the nozzle portion is formed integrally with an end portion of the secondary joint pipe. A refrigeration cycle system including a compressor, a condenser, an expansion valve, and an evaporator, wherein the motor-operated valve according to any one of claims 1 to 4 is used as the expansion valve. A refrigeration cycle system characterized by that.

Images