JP2013234726A - Electric valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce noise by restraining vibration or the like of a secondary joint pipe, by stabilizing a flow of a refrigerant in a valve port, in an electric valve for controlling a flow rate of the refrigerant by opening-closing the valve port by a needle valve.SOLUTION: A first valve port 11 of an inner diameter D1 and a second valve port 12 of an inner diameter D2 are formed in a cross-sectional circular shape in a valve housing 1. D1<D2<D3 is satisfied to an inner diameter D3 of the secondary joint pipe 22. An inner diameter ratio D2/D1 of the inner diameter D2 of the second valve port 12 and the inner diameter D1 of the first valve port 11 satisfies 1.05≤D2/D1≤1.85. A length ratio L2/L1 of the length L2 of the second port 12 and the length L1 of the first port 11 satisfies 20≤L2/L1≤45. A taper part 13 connecting the first valve port 11 and the second valve port 12 is formed, and the taper angle α3 of the taper part 13 satisfies 90°≤α3≤150°. Pressure is not swiftly restored in the second port 12. The flow of refrigerant is straightened in the second port 12.

Description

  The present invention relates to a needle valve type electric valve that controls the flow rate of refrigerant in an air conditioner or the like, and more particularly to an electric valve having an improved valve port shape with respect to the needle valve.

  Conventionally, in a refrigeration cycle, noise accompanying the passage of fluid, which is generated from a motor-operated valve that controls the flow rate of refrigerant, often becomes a problem. For example, Japanese Patent Application Laid-Open No. 2012-47213 (Patent Document 1) and Japanese Patent Application Laid-Open No. 2010-19406 (Patent Document 2) have been disclosed as motor-operated valves that take such noise countermeasures.

  In the electric valve of Patent Document 1, the valve port is constituted by a first valve port and a second valve port, and an inner diameter D1 of the first valve port, an inner diameter D2 of the second valve port, and an inner diameter D3 of the secondary joint pipe. The relationship is such that D1 <D2 <D3.

  In the motor-driven valve of Patent Document 2, the inner diameter of the narrowest part of the valve port (valve orifice) and the angle of the conical valve port are set.

JP 2008-232290 A JP 2010-19406 A

  The invention of Patent Document 1 also has an effect of reducing noise as compared with the previous structure, but may generate noise in a specific refrigerant state. For example, in Patent Document 1, as shown in FIG. 9, there are a first port a and a second port b having a larger inner diameter than the first port a, and the first port a and the second port b There is a taper c between them, but the inner diameter of the second port b is larger than the inner diameter of the first port a. Although the flow rate of the refrigerant is large in the gap between the first port a and the needle valve d, the flow rate immediately decreases in the second port b, and the flow state becomes a diffusion flow. Also, the pressure recovers rapidly. For this reason, there is a problem that cavitation bursts easily occur, leaving room for improvement. This is the same as in Patent Document 2.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a motor-operated valve with reduced noise by using new conditions for the valve port.

  In the motor-operated valve according to the first aspect, a primary joint pipe communicates with a valve chamber formed in the valve housing, and a secondary joint pipe can communicate with the valve chamber via a valve port, and is arranged coaxially with the valve port. In the motor-operated valve configured to control the flow rate of fluid flowing in from the primary joint pipe and flowing out to the secondary joint by moving the provided needle valve in the axial direction to open and close the valve port, The valve port includes a first valve port having an inner diameter D1 located on the valve chamber side and a second valve port having an inner diameter D2 located on the secondary joint pipe side. The relationship between the inner diameter D2 of the two-valve port and the inner diameter D3 of the secondary joint pipe is D1 <D2 <D3, and the ratio D2 / D1 between the inner diameter D2 of the second valve port and the inner diameter of the first valve port is 1.05 ≦ D2 / D1 ≦ 1.85 Characterized by being configured to.

  A motor-driven valve according to a second aspect is the motor-operated valve according to the first aspect, wherein a ratio L2 / L1 between the length L2 of the second port and the length L1 of the first port is 20 ≦ L2 / L1 ≦ 45. It is configured to be in the range of

  The motor-driven valve according to claim 3 is the motor-operated valve according to claim 1 or 2, wherein a tapered portion that connects the first valve port and the second valve port is formed, and a taper angle α3 of the tapered portion is set. , 90 ° ≦ α3 ≦ 150 °.

  According to the electric valve of claim 1, the ratio D2 / D1 between the inner diameter D2 of the second valve port and the inner diameter of the first valve port is in the range of 1.05 ≦ D2 / D1 ≦ 1.85, Since the inner diameter of the valve port is relatively small, when the refrigerant flowing from the gap between the first valve port and the needle valve flows out to the second valve port, the pressure does not recover rapidly, thereby suppressing cavitation bursting. Noise can be reduced.

  According to the electric valve of claim 2, the ratio L2 / L1 of the length L2 of the second port and the length L1 of the first port is in the range of 20 ≦ L2 / L1 ≦ 45, and the length of the first valve port Since the length of the second valve port is sufficiently long compared to the above, the refrigerant flow is rectified at the second valve port, the refrigerant flow can be stabilized, and noise can be further reduced.

  According to the electric valve of claim 3, the taper angle α3 of the taper portion connecting the first valve port and the second valve port is in the range of 90 ° ≦ α3 ≦ 150 °, and the first valve port and the needle valve Since the refrigerant flowing from the gap flows to the second valve port following the tapered portion, the pressure is not rapidly recovered and noise can be reduced.

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 an actual measurement example of the dimensional ratio between D2 and D1 and the noise reduction value for the motor-operated valve according to the embodiment of the present invention. It is an actual measurement example of the noise reduction value with respect to the dimension ratio of D2 and D1, when changing the taper angle of the taper part about the electric valve of the embodiment of the present invention. It is an actual measurement example of the dimension ratio of L2 and L1 and the noise reduction value for the motor-operated valve of the embodiment of the present invention. It is a figure which shows the noise reduction value with respect to the dimensional ratio of D2 and D1 by making the taper angle into a horizontal axis in the actual measurement example of FIG. It is a figure explaining an example of the problem of the conventional motor operated valve.

  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. 3 is a diagram for explaining the operation of the valve port in the motor-operated valve according to the embodiment. FIG. 4 is a diagram illustrating an example of an air conditioner using the electric valve of the embodiment.

  First, the air conditioner according to the embodiment will be described with reference to FIG. The air conditioner includes the electric valve 10 of the embodiment, the outdoor heat exchanger 20 mounted on the outdoor unit 100, the indoor heat exchanger 30 mounted on the indoor unit 200, the flow path switching valve 40, and the compressor 50. These elements are connected by conduits as shown in the figure to constitute a heat pump type refrigeration cycle.

  The flow path of the refrigeration cycle is switched to the two flow paths of the heating mode and the cooling mode by the flow path switching valve 40, and the refrigerant compressed by the compressor 50 is switched in the heating mode, as indicated by solid arrows. The refrigerant that flows into the indoor heat exchanger 30 from the valve 40 and flows 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.

  The motor-operated valve 10 functions as a 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, and the room is heated. . 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.

  Here, in the heating mode, in the pipe line 60, the refrigerant flowing into the primary joint pipe 21 of the motor operated valve 10 may be liquefied, and the pipe line 60 is filled with the liquid refrigerant. For this reason, vibration is generated by passage of the refrigerant through the motor-operated valve 10, and this vibration is transmitted to the indoor unit 200 side via the pipe line 60, and noise is generated in the indoor unit 200. Therefore, as will be described later, the motor-operated valve 10 improves the valve port so that the refrigerant flows from the primary joint pipe 21 into the motor-operated valve 10 main body and the refrigerant flows out from the secondary joint pipe 22 in the heating mode. The refrigerant passing sound is reduced.

  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, and a cylindrical cylinder-shaped valve chamber 1 </ b> A is formed in the valve housing 1. Further, the valve housing 1 is formed with a first valve port 11 and a second valve port 12 having a circular cross-section with the axis X as the center. A tapered portion 13 is formed between the first valve port 11 and the second valve port 12. Further, a primary joint pipe 21 communicating with the valve chamber 1A from the side surface side is attached to the valve housing 1, and a secondary joint pipe 22 is attached to one end portion in the axis X direction of the valve chamber 1A. The valve chamber 1 </ b> A and the secondary joint pipe 22 can be connected to each other via the first valve port 11 and the second valve port 12.

  A support member 3 is attached to the upper portion of the valve housing 1. A long guide hole 3a is formed in the support member 3 in the direction of the axis X, and a cylindrical valve holder 4 is slidably fitted in the guide hole 3a in the direction of the axis X. The valve holder 4 is attached coaxially with the valve chamber 1A, and a valve body 5 having a needle valve 5a at the end is fixed to the lower end portion of the valve holder 4. A spring receiver 41 is provided in the valve holder 4 so as to be movable in the direction of the axis X, and a compression coil spring 42 is attached between the spring receiver 41 and the valve body 5 with a predetermined load applied. ing.

  A case 61 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 61, a magnet rotor 62 having an outer peripheral portion magnetized in multiple poles is rotatably provided, and a rotor shaft 63 is fixed to the magnet rotor 62. The upper end portion of the rotor shaft 63 is rotatably fitted in a cylindrical guide 64 suspended from the ceiling portion of the case 61. A stator coil 65 is disposed on the outer periphery of the case 61. When a pulse signal is given to the stator coil 65, the magnet rotor 62 is rotated according to the number of pulses. The rotation of the magnet rotor 62 causes the rotor shaft 63 integrated with the magnet rotor 62 to rotate. A rotation stopper mechanism 66 for the magnet rotor 62 is provided on the outer periphery of the guide 64.

  The upper end portion of the valve holder 4 is engaged with the lower end portion of the rotor shaft 63 of the stepping motor 6, and the valve holder 4 is supported in a state of being rotatably suspended by the rotor shaft 63. The rotor shaft 63 is formed with a male screw portion 63 a, and the male screw portion 63 a is screwed into a female screw portion 3 b formed on the support member 3.

  With the above configuration, the rotor shaft 63 moves in the axis X direction as the magnet rotor 62 rotates. The valve body 5 moves in the direction of the axis X together with the valve holder 4 by the movement of the rotor shaft 63 in the direction of the axis X accompanying this rotation. And the valve body 5 increases / decreases the opening area of the 1st valve port 11 in the part of the needle valve 5a, and controls the flow volume of the fluid which flows into the secondary joint pipe 22 from the primary joint pipe 21.

  The first valve port 11 and the second valve port 12 have a cylindrical shape, and as shown in FIG. 2, the inner diameter D1 of the first valve port 11 is a dimension that matches the outer periphery of the needle valve 5a. The inner diameter D2 of the second valve port 12 is slightly larger than the inner diameter D1 of the first valve port 11 and smaller than the inner diameter D3 of the secondary joint pipe 22. The length L1 of the first valve port 11 is smaller than the inner diameter D1, and the length L2 of the second valve port 12 is sufficiently larger than the length L1 of the first valve port 11. The inner surface of the taper portion 13 has a truncated cone shape whose inner diameter increases from the first valve port 11 to the second valve port 12, and the taper angle α3, which is the opening angle of the taper portion 13, and the needle valve 5a. The angle α2 and the angle α1 formed by the needle valve 5a and the tapered portion 13 are set as appropriate. Although these dimensions and angle conditions are illustrated, they will be described later.

  As shown in FIG. 3, the refrigerant passing through the gap between the needle valve 5 a and the first valve port 11 flows to the secondary joint pipe 22 through the second valve port 12. At this time, the refrigerant flowing through the gap between the needle valve 5 a and the first port 11 flows along the inner wall of the second port 12 following the tapered portion 13. The inner diameter D2 of the second port 12 is only slightly larger than the inner diameter D1 of the first port 11, and the pressure is not rapidly recovered while flowing from the first port 11 to the second port 12. Further, since the length L2 of the second port 12 is sufficiently long, the flow of the refrigerant is rectified at the second port 12. Therefore, the burst of cavitation can be suppressed, the flow of the refrigerant can be stabilized, and the vibration of the secondary joint pipe 22 can be suppressed to reduce noise.

  The motor-operated valve 10 in the embodiment is applied to a refrigeration cycle in which the refrigerant pressure has the following conditions. The pressure in the primary joint pipe 21 is 2.8 to 3.4 (MPa: megapascal), and the pressure in the secondary joint pipe 22 is 1.2 to 1.8 (MPa). And with respect to such conditions, the dimensions of each part of the first port 11, the second port 12, the taper part 13, and the secondary joint 22 are set so as to satisfy the following conditions. Such noise reduction effect can be obtained.

The inner diameter D1 of the first port 11 is
1mm ≦ D1 ≦ 4.5mm,
The dimension ratio D2 / D1 between the inner diameter D2 of the second port 12 and the inner diameter D1 of the first port 11 is:
1.05 ≦ D2 / D1 ≦ 1.85 (1)
Range.

The length L1 of the first port 11 is
L1 <0.5mm
The ratio L2 / L1 between the length L2 of the second port 12 and the length L1 of the first port 11 is:
20 ≦ L2 / L1 ≦ 45 (2)
Range.

The taper angle α3 of the taper portion 13 is
90 ° ≦ α3 ≦ 150 ° (3)
Range.

The angle α2 of the needle valve 5a is
4 ° ≦ α2 ≦ 50 °
Range.

The angle α1 formed between the needle valve 5a and the tapered portion 13 is
46 ° ≦ α1 ≦ 100 °
Range.

  FIG. 5 is an actual measurement example of the dimension ratio between D2 and D1 and the noise reduction value for the motor-operated valve of the embodiment, and has a structure in which D2 / D1 = 1 (a structure in which there is no step between the first port 11 and the second port 12). The noise reduction value with respect to is shown. The operating conditions are a pressure in the primary joint pipe 11 of 2.8 to 3.4 (MPa) and a pressure in the secondary joint pipe 22 of 1.2 to 1.8 (MPa). The flow of the refrigerant is in the direction from the primary joint pipe 11 to the secondary joint pipe 12. The inner diameter D3 of the secondary joint pipe 22 is 6.4 mm. The length L1 of the first port 11 is L1 = 0.35 mm within the range of 0.2 mm <L1 <0.5 mm, and L2 / L1 = 30. D2 / D1 = 1, D2 / D1 = 1.02, D2 / D1 = 1.05, D2 / D1 = 1.3, D2 / D1 = 1 with respect to the inner diameter D1 = 1.9 mm of the first port 11 .6, D2 / D1 = 1.85, D2 / D1 = 1.9, and D2 / D1 = 2, the noise reduction values when D2 is changed are shown. As can be seen from this figure, the noise is low particularly in a range satisfying the conditional expression (1) (1.05 ≦ D2 / D1 ≦ 1.85).

  FIG. 6 is an actual measurement example of the noise reduction value with respect to the dimensional ratio of D2 and D1 when the taper angle α3 of the taper portion 13 of the motor-operated valve of the embodiment is changed, and a structure in which α3 = 180 ° (first) The noise reduction value for a structure in which there is no taper between the port 11 and the second port 12 is shown. The operating conditions are a pressure in the primary joint pipe 11 of 2.8 to 3.4 (MPa) and a pressure in the secondary joint pipe 22 of 1.2 to 1.8 (MPa). The flow of the refrigerant is in the direction from the primary joint pipe 11 to the secondary joint pipe 12. The inner diameter D3 of the secondary joint pipe 22 is 6.4 mm. The length L1 of the first port 11 is L1 = 0.35 mm within the range of 0.2 mm <L1 <0.5 mm, and L2 / L1 = 30. For each of α3 = 90 °, α3 = 105 °, α3 = 120 °, α3 = 150 °, and α3 = 180 °, D2 / D1 = 1.02 with respect to the inner diameter D1 = 1.9 mm of the first port 11. D2 / D1 = 1.05, D2 / D1 = 1.3, D2 / D1 = 1.85, and D2 / D1 = 1.9, the noise reduction values when D2 is changed are shown. As can be seen from this figure, as in FIG. 5, the noise is reduced particularly in a range satisfying conditional expression (1) (1.05 ≦ D2 / D1 ≦ 1.85).

  FIG. 7 is an actual measurement example of the dimensional ratio between L2 and L1 and the noise reduction value for the motor-operated valve of the embodiment, and shows the noise reduction value for the structure where D2 / D1 = 1. The operating conditions are a pressure in the primary joint pipe 11 of 2.8 to 3.4 (MPa) and a pressure in the secondary joint pipe 22 of 1.2 to 1.8 (MPa). The flow of the refrigerant is in the direction from the primary joint pipe 11 to the secondary joint pipe 12. The inner diameter D1 of the first port 11 is 1.9 mm, and the inner diameter D3 of the secondary joint pipe 22 is 6.4 mm. The length L1 of the first port 11 is L1 = 0.35 mm in the range of 0.2 mm <L1 <0.5 mm, whereas L2 / L1 = 13, L2 / L1 = 15, L2 / L1 = 20, L2 / L1 = 25, L2 / L1 = 30, L2 / L1 = 40, L2 / L1 = 45, L2 / L1 = 50, L2 / L1 = 60, and the noise reduction value when changing L2 Show. As can be seen from this figure, the noise is low particularly in a range satisfying the conditional expression (2) (20 ≦ L2 / L1 ≦ 45).

  FIG. 8 is a diagram showing noise reduction values when the embodiment of FIG. 6 is D2 / D1 = 1.05, D2 / D1 = 1.3, and D2 / D1 = 1.85 with the taper angle α3 as the horizontal axis. is there. In particular, noise is low in a range (90 ° ≦ α3 ≦ 100 °) that satisfies the conditional expression (3).

  In the embodiment, an example in which the first port, the second port, and the tapered portion are formed in the valve housing has been described. However, as in Patent Document 1, a separate valve seat member is provided in the valve housing. You may make it form a 1st port, a 2nd port, and a taper part in a member.

DESCRIPTION OF SYMBOLS 1 Valve housing 1A Valve chamber 11 1st valve port 12 2nd valve port 13 Tapered part 21 Primary joint pipe 22 Secondary joint pipe 3 Support member 3a Guide hole 3b Female thread part 4 Valve holder 41 Spring receiver 42 Compression coil spring 5a Needle valve 5 Valve body 6 Stepping motor 61 Case 62 Magnet rotor 63 Rotor shaft 63a Male thread portion 64 Guide 65 Stator coil 66 Rotation stopper mechanism X Axis

Claims (3)

A primary joint pipe communicates with a valve chamber formed in the valve housing, and a secondary joint pipe can communicate with the valve chamber via a valve port. A needle valve disposed coaxially with the valve port is connected in an axial direction. In the motor operated valve that controls the flow rate of the fluid that flows in from the primary joint pipe and flows out to the secondary joint by opening and closing the valve port.
The valve port is constituted by a first valve port having an inner diameter D1 located on the valve chamber side and a second valve port having an inner diameter D2 located on the secondary joint pipe side,
The relationship between the inner diameter D1 of the first valve port, the inner diameter D2 of the second valve port, and the inner diameter D3 of the secondary joint pipe is D1 <D2 <D3, and the inner diameter D2 of the second valve port and the first valve A motor-operated valve configured such that a ratio D2 / D1 of an inner diameter of a port is in a range of 1.05 ≦ D2 / D1 ≦ 1.85.   The electric motor according to claim 1, wherein a ratio L2 / L1 of the length L2 of the second port and the length L1 of the first port is in a range of 20 ≦ L2 / L1 ≦ 45. valve.   A taper portion that connects the first valve port and the second valve port is formed, and a taper angle α3 of the taper portion is configured to be in a range of 90 ° ≦ α3 ≦ 150 °. Item 3. The electric valve according to item 1 or 2.

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