JP2023174727A - Motor valve and refrigeration cycle system - Google Patents

Abstract

To provide a motor valve having a two-stage flow rate control region for performing flow rate control of refrigerant in a small flow rate control region using a restriction part between a sub valve port and a needle valve formed in a main valve element while setting the main valve element in the state of being seated on a main valve seat, for improving the quietness in the small flow rate control region.SOLUTION: A motor valve includes a main valve element provided in a main valve chest 1R for opening/closing a main valve port 13a opening to the main valve chest 1R, and a sub valve element 4 to be moved in the direction of an axial line L of a sub valve port 3a formed in the main valve element 3 for controlling the opening of the sub valve port 3a, the sub valve element 4 including a needle valve 42 inserted through the sub valve port 3a in the direction of the axial line L. In the main valve element 3, a restriction flow path 3c having a uniform flow path cross section area is provided which is communicated from the main valve chest 1R to a restriction part C between the sub valve port 3a and the needle valve 42 in the direction of intersecting with the axial line L.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electric valve used in a refrigeration cycle system and the like, and a refrigeration cycle system.

BACKGROUND ART Conventionally, as an electric valve provided in a refrigeration cycle of an air conditioner, there is an electric valve that controls the flow rate in a small flow rate control area and a large flow rate control area. Such a motor-operated valve has applications (for example, as a dehumidification valve) that are mounted on an indoor unit, and is disclosed in, for example, Japanese Patent Application Publication No. 2019-132347 (Patent Document 1).

JP 2019-132347 Publication

This type of electric valve performs dehumidification operation in the small flow rate control area, for example, and in this small flow rate control area, the main valve port of the main valve seat is fully closed by the main valve element, and the main valve element is The refrigerant is configured to pass through a constriction between the formed sub-valve port and the needle valve (sub-valve body). However, in the conventional motor-operated valve, when the flow rate is in the small flow control range, fluid flows from the valve chamber (main valve chamber) to the auxiliary valve chamber through the communication hole, and through this auxiliary valve chamber, the fluid flows into the auxiliary valve port and the auxiliary valve chamber. The fluid is configured to flow out from the constriction section between the valve body and the valve body. Therefore, the fluid flowing from the main valve chamber to the throttle section is once expanded when flowing into the sub-valve chamber from the communication hole. Therefore, there is a problem in that the sub-valve body vibrates due to pressure fluctuations of the refrigerant in the sub-valve chamber, resulting in noise.

In the present invention, the main valve body is seated on the main valve seat, and the flow rate of the refrigerant is controlled in a small flow rate control range using a constriction portion formed in the main valve body between the sub-valve port and the needle valve. An object of the present invention is to improve quietness in a small flow rate control area in a motor-operated valve having a flow rate control area of stages.

The motor-operated valve of the present invention includes a valve main body having a main valve chamber, a partition section that partitions a space within the main valve chamber, a rotor shaft having a male threaded section formed on the outer periphery, and a rotor shaft installed in the valve main body and the male threaded section. a guide member having a female threaded portion that is screwed together; a screw feeding mechanism that is inserted in the axial direction into a sub-valve port provided on the rotor shaft and formed in the partitioned portion, and includes the male threaded portion and the female threaded portion; a needle valve that moves in the axial direction to control the opening degree of the auxiliary valve port, the motor-operated valve that throttles the fluid in a throttle section between the auxiliary valve port and the needle valve; The portion includes a throttle flow path having a uniform cross-sectional area from the main valve chamber to the throttle portion between the sub-valve port and the needle valve in a direction intersecting the axis; A needle guide hole coaxially facing the sub-valve port is formed, and the needle valve has a straight portion in the axial direction, and the straight portion is configured to be guided along the axis by the needle guide hole. and a vertical hole connecting the secondary valve port and the needle guide hole in the axial direction, the vertical hole is coaxial and has the same diameter as the secondary valve port, and the throttle flow path is connected to the vertical hole. The outer diameter of the straight portion is smaller than the outer diameter of the male threaded portion.

Further, in this case, the guide member includes a press-fitting part that is press-fitted into the inner circumferential surface of the valve body, a cylindrical guide part that is arranged in the axial direction with the press-fitting part and has a smaller diameter than the press-fitting part, and the guide part. and a holder part having an outer diameter equal to or less than the outer diameter of the guide part, and the female thread part is preferably formed at the center of the holder part.

Further, it is preferable that a cylindrical expansion hole is formed, which communicates with the opening of the auxiliary valve port on the side opposite to the side where the vertical hole is located, and has an inner diameter larger than the inner diameter of the auxiliary valve port.

Further, the needle valve includes the straight part and a needle whose base end is continuous with the one end in the axial direction of the straight part and whose diameter is reduced toward the distal end, and the needle has an inner circumferential surface of the sub-valve port. It is preferable that a value twice the length from the base end to the distal end of the outer circumferential surface of the needle forming an acute angle between the needles is larger than the outer diameter of the straight part.

Further, the needle valve includes the straight part and a needle whose base end is continuous with the one end in the axial direction of the straight part and whose diameter is reduced toward the distal end,
It is preferable that the length of the needle in the axial direction from the base end to the tip end is larger than the radius of the straight part.

Further, it is preferable that the needle guide hole intersects the throttle channel along the axis.

Preferably, a plurality of the throttle channels are formed around the axis, and the sum of the cross-sectional areas of the plurality of throttle channels is set to be larger than the cross-sectional area of the sub-valve port.

Further, the refrigeration cycle system of the present invention is a refrigeration cycle system including a compressor, an indoor heat exchanger, an outdoor heat exchanger, and an electronic expansion valve, and the electric valve according to any one of the above It is characterized in that it is used as the electronic expansion valve.

According to the electric valve and refrigeration cycle system of the present invention, in a state of small flow rate control by the throttle part (gap) between the sub-valve body and the sub-valve port, the fluid from the main valve chamber to the throttle part flows through the flow path. Since the refrigerant only passes through a throttle channel with a uniform cross-sectional area, pressure fluctuations in the refrigerant are suppressed and the state of the refrigerant is stabilized, and the needle valve is guided to the vicinity of the sub-valve port by the needle valve guide hole. Vibrations of the sub-valve body can be suppressed, and quietness is improved by providing a muffling member at the opening on the valve chamber side of the throttle channel of the main valve body and/or at the opening of the expansion hole.

FIG. 3 is a longitudinal cross-sectional view of the electric valve according to the embodiment of the present invention in a small flow rate control region state. FIG. 2 is an enlarged vertical cross-sectional view of the main part of the motor-operated valve of the embodiment in a state where the sub-valve body is slightly elevated from the small flow rate control region state shown in FIG. 1; It is an enlarged view showing a modification of the main valve body in the electric valve of the embodiment. 1 is a diagram showing a refrigeration cycle system according to an embodiment of the present invention.

Next, embodiments of the electric valve and refrigeration cycle system of the present invention will be described with reference to the drawings. Fig. 1 is a longitudinal sectional view of the motor-operated valve according to the embodiment in the small flow control region state, and Fig. 2 is an enlarged view of the main part of the motor-operated valve according to the embodiment in the small flow control region state shown in Fig. 1 with the sub-valve body slightly elevated. FIG. Note that the concept of "up and down" in the following description corresponds to the up and down in the drawings of FIGS. 1 and 2. This electric valve 100 includes a valve housing 1 , a guide member 2 , a main valve body 3 , a sub-valve body 4 , and a drive section 5 .

The valve housing 1 is made of, for example, brass or stainless steel and has a substantially cylindrical shape, and has a main valve chamber 1R inside thereof. A first joint pipe 11 that communicates with the main valve chamber 1R is connected to one side of the outer periphery of the valve housing 1, and a second joint pipe 12 is connected to a cylindrical portion extending downward from the lower end. Further, a main valve seat 13 is formed on the main valve chamber 1R side of the second joint pipe 12 of the valve housing 1, and the inside of this main valve seat 13 is a main valve port 13a. The main valve port 13a is a cylindrical through hole centered on the axis L, and the second joint pipe 12 is communicated with the main valve chamber 1R via the main valve port 13a. Note that the first joint pipe 11 and the second joint pipe 12 are fixed to the valve housing 1 by brazing or the like.

A guide member 2 is attached to an opening at the upper end of the valve housing 1 . The guide member 2 includes a press-fit part 21 that is press-fitted into the inner peripheral surface of the valve housing 1, approximately cylindrical guide parts 22 and 23 that have a smaller diameter than the press-fit part 21 and are located above and below the press-fit part 21, and an upper guide. It has a holder part 24 extending above the part 22 and a ring-shaped flange part 25 provided on the outer periphery of the press-fitting part 21 . The press-fitting part 21, the guide parts 22, 23, and the holder part 24 are constructed as an integral part made of resin. Further, the flange portion 25 is, for example, a metal plate made of brass, stainless steel, or the like, and is integrally provided with the resin press-fit portion 21 by insert molding.

The guide member 2 is assembled to the valve housing 1 through a press-fitting portion 21 and is fixed to the upper end portion of the valve housing 1 via a flange portion 25 by welding. Further, in the guide member 2, a cylindrical guide hole 2A coaxial with the axis L is formed inside the press-fitting part 21 and the upper and lower guide parts 22, 23, and a guide hole 2A is formed in the center of the holder part 24. A female threaded portion 24a coaxial with the threaded portion 24a and its threaded hole are formed. The main valve body 3 is disposed inside the guide hole 2A inside the lower guide portion 23.

The main valve body 3 includes a main valve part 31 that seats and leaves the main valve seat 13, and a holding part 32 that holds the sub valve body 4. A cylindrical expansion hole 3A is formed inside the main valve part 31, and a cylindrical sub-valve guide hole 3B is formed inside the holding part 32. Between the main valve part 31 and the holding part 32, a cylindrical sub-valve port 3a is formed that opens toward the expansion hole 3A side with the axis L as the center, and is located along the axis L on the sub-valve guide hole 3B side. A cylindrical needle guide hole 3b coaxial with the needle guide hole 3b is formed.

In addition, at the connecting portion between the main valve portion 31 and the holding portion 32 of the main valve body 3, a throttle portion C between the sub valve port 3a and a needle valve 42, which will be described later, is located in a direction intersecting the axis L from the main valve chamber 1R. A throttle channel 3c is formed that communicates with the flow path (FIG. 2). The throttle flow path 3c has a cylindrical shape such that the cross-sectional area of the flow path is uniform from the main valve chamber 1R side to the sub-valve port 3a side. In this embodiment, a plurality (for example, four) of the throttle channels 3c are formed radially at positions that are rotationally symmetrical about the axis L. The total cross-sectional area of the four throttle channels 3c is set to be larger than the cross-sectional area of the sub-valve port 3a. Note that the "flow path cross-sectional area" is a cross-sectional area in a plane perpendicular to the direction in which the fluid flows. In addition, here, an example is shown in which there are four throttle channels 3c, but if the total cross-sectional area of the throttle channels 3c is set larger than the flow channel area of the sub-valve port 3a, two throttle channels 3c can be used. It is also possible to have multiple copies of the above.

The main valve body 3 has a retainer 34 at the upper end of the holding part 32, and a main valve spring 35 between the retainer 34 and the upper end of the guide hole 2A of the guide member 2. 35 urges the main valve body 3 in the direction of the main valve seat 13 (closed direction).

The sub-valve body 4 is formed integrally with the rotor shaft 51 at the lower end of the rotor shaft 51, and the sub-valve body 4 includes a guide boss portion 41 and a needle valve 42. Further, as shown in FIG. 2, the needle valve 42 of the sub-valve body 4 is inserted into the sub-valve port 3a in the direction of the axis L, and the needle valve 42 is formed from a cylinder whose center line is the axis L. The needle 42b is composed of a straight portion 42a and a needle 42b whose diameter is reduced toward the tip end. Further, the outer diameter of the straight portion 42a is slightly smaller than the inner diameter of the sub-valve port 3a, and there is a restriction between the straight portion 42a and the sub-valve port 3a or between the needle 42b and the sub-valve port 3a. A portion C (the portion surrounded by a dashed-dotted line) is formed. A small flow rate control is performed by causing a small flow rate of the refrigerant to flow through this constricted portion C. An annular washer 43 made of lubricating resin is disposed at the upper end of the guide boss 41, and the washer 43 and the guide boss 41 are slidably inserted into the sub-valve guide hole 3B. ing.

Further, the straight portion 42a of the needle valve 42 is slidably guided by the inner periphery of the needle guide hole 3b that intersects with the throttle channel 3c along the axis L near directly above the sub-valve port 3a.

A case 14 is airtightly fixed to the upper end of the valve housing 1 by welding or the like, and a drive section 5 is configured inside and outside the case 14. The drive unit 5 includes a stepping motor 5A, a screw feeding mechanism 5B that advances and retreats the sub-valve body 4 by rotation of the stepping motor 5A, and a stopper mechanism 5C that restricts the rotation of the stepping motor 5A.

The stepping motor 5A includes a rotor shaft 51, a magnet rotor 52 rotatably disposed inside a case 14, a stator coil 53 disposed opposite to the magnet rotor 52 on the outer periphery of the case 14, and other components shown in the figure. It is made up of a yoke, exterior members, etc. The rotor shaft 51 is attached to the center of the magnet rotor 52 via a bush, and a male threaded portion 51a is formed on the outer periphery of the rotor shaft 51 on the guide member 2 side. The male threaded portion 51a is screwed into the female threaded portion 24a of the guide member 2, so that the guide member 2 supports the rotor shaft 51 on the axis L. The female threaded portion 24a of the guide member 2 and the male threaded portion 51a of the rotor shaft 51 constitute a screw feeding mechanism 5B. A cylindrical portion 14a that holds the rotation stopper mechanism 5C is provided on the inner ceiling of the case 14, and a guide member 52 that guides the upper end of the rotor shaft 51 is disposed within the cylindrical portion 14a.

With the above configuration, when the stepping motor 5A is driven, the magnet rotor 52 and the rotor shaft 51 rotate, and the screw feeding mechanism 5B of the male threaded portion 51a of the rotor shaft 51 and the female threaded portion 24a of the guide member 2 causes the magnet rotor 52 to rotate. At the same time, the rotor shaft 51 moves in the direction of the axis L. Then, the sub-valve body 4 moves forward and backward in the direction of the axis L, and the needle valve 42 approaches or separates from the sub-valve port 3a. Further, when the needle valve 42 rises, the washer 43 engages with the retainer 34 of the main valve body 3, and the main valve body 3 moves together with the sub valve body 4 and leaves the main valve seat 13. Note that the magnet rotor 52 is formed with a protrusion 52a, and as the magnet rotor 52 rotates, the protrusion 52a operates the rotation stopper mechanism 5C, and the lowermost position of the rotor shaft 51 (and the magnet rotor 52) and The top position is restricted.

In the small flow rate control region state of FIG. 1, the main valve port 13a is closed with the main valve body 3 seated on the main valve seat 13, and the opening degree of the sub valve port 3a is controlled by the needle valve 42 of the sub valve body 4. controlled, and small flow control is performed. At this time, the refrigerant in the main valve chamber 1R flows through the throttle channel 3c to the throttle section C, but this refrigerant flows to the throttle section C at a stable pressure due to the uniform cross-sectional area of the throttle channel 3c. . Then, this refrigerant is expanded when flowing out from the constriction portion C to the expansion hole 3A. That is, since the flow of the refrigerant is stable from the main valve chamber 1R until it passes through the throttle part C, vibrations and the like in the electric valve can be prevented.

In addition, since the plurality of throttle channels 3c are provided at rotationally symmetrical positions around the axis L, the refrigerant passing through the throttle channels 3c causes the needle valve 42 to be largely biased in the direction intersecting the axis L. Further, since the straight portion 42a of the needle valve 42 is guided by the needle guide hole 3b in the vicinity directly above the auxiliary valve port 3a, the vibration of the auxiliary valve body 4 due to the flow of refrigerant is suppressed. More restrained.

Note that the needle 42b of the needle valve 42 moves forward and backward with respect to the sub-valve port 3a, and the flow passage cross-sectional area of the constriction portion C, which is the gap between the outer periphery of the needle 42b and the sub-valve port 3a, is also a plurality of apertures. It is always smaller than the total cross-sectional area of the flow paths 3c. Thereby, the low flow rate control by the sub-valve body 4 is performed with high accuracy without being affected by the throttle channel 3c.

FIG. 3 is an enlarged vertical cross-sectional view of the main part in a small flow rate control region state showing a modification of the motor-operated valve of the embodiment. In this modification described below, the overall configuration of the motor-operated valve other than its characteristic parts is shown in FIGS. 1 and 2. It is similar to In this modification, in the main valve body 3', the main valve part 31 and the holding part 32 are configured as separate parts, and a sound deadening member 36 is disposed at the opening of the expansion hole 3A of the main valve part 31, and the holding part 32 and the main valve part 31, a muffling member 37 is disposed at the opening of the throttle channel 3c on the main valve chamber 1R side. These sound deadening members 36 and 37 absorb the sound of the refrigerant passing, further enhancing the quiet effect. Note that only one of the sound deadening members 36 and 37 may be used.

FIG. 4 is a diagram showing a refrigeration cycle system according to an embodiment of the present invention, and the refrigeration cycle system according to the embodiment will be explained based on the diagram. Refrigeration cycle systems are used, for example, in air conditioners such as household air conditioners. The motor-operated valve 100 of the embodiment is provided between the first indoor heat exchanger 91 (operates as a cooler during dehumidification) and the second indoor heat exchanger 92 (operates as a heater during dehumidification) of the air conditioner. The compressor 95, four-way valve 96, outdoor heat exchanger 94, and electronic expansion valve 93 constitute a heat pump refrigeration cycle. The first indoor heat exchanger 91, the second indoor heat exchanger 92, and the electric valve 100 are installed indoors, and the compressor 95, four-way valve 96, outdoor heat exchanger 94, and electronic expansion valve 93 are installed outdoors. They have heating and cooling equipment.

In the electric valve 100 of the embodiment as a dehumidification valve, the main valve body is fully opened during cooling or heating other than during dehumidification, and the first indoor heat exchanger 91 and the second indoor heat exchanger 92 are connected to one indoor heat exchanger. It is considered a heat exchanger. The integrated indoor heat exchanger and outdoor heat exchanger 94 function alternatively as an "evaporator" and a "condenser." That is, the electric valve 93 as an electronic expansion valve is provided between the evaporator and the condenser.

Note that the present invention is not limited to the embodiments described above, and includes other configurations that can achieve the object of the present invention, and the present invention also includes the following modifications. For example, in the above embodiment, the electric valve 100 used in an air conditioner such as a domestic air conditioner is illustrated, but the electric valve of the present invention is not limited to a household air conditioner, but may be used in a commercial air conditioner. It is applicable not only to air conditioners but also to various types of refrigerators.

The embodiments of the present invention have been described above in detail with reference to the drawings, and other embodiments have also been described in detail, but the specific configuration is not limited to these embodiments. Even if there are changes in the design within the scope of the invention, they are included in the present invention.

1 Valve housing 1R Main valve chamber 11 First joint pipe 12 Second joint pipe 13 Main valve seat 13a Main valve port L Axis C Throttle part 2 Guide member 2A Guide hole 24 Holder part 24a Female thread part 3 Main valve body 31 Main valve part 32 Holding section 3a Sub-valve port 3b Needle guide hole 3c Throttle flow path 4 Sub-valve body 41 Guide boss section 42 Needle valve 42a Straight section 42b Needle 5 Drive section 5A Stepping motor 5B Screw feed mechanism 5C Stopper mechanism 51 Rotor shaft 51a Male thread Part 52 Magnet rotor 53 Stator coil 91 First indoor heat exchanger 92 Second indoor heat exchanger 93 Electronic expansion valve 94 Outdoor heat exchanger 95 Compressor 96 Four-way valve 100 Electrically operated valve

Claims (8)

A valve body having a main valve chamber, a partition section that partitions a space within the main valve chamber, a rotor shaft having a male threaded section formed on the outer periphery, and a female threaded section installed in the valve body and into which the male threaded section is screwed. a guide member provided on the rotor shaft, and a screw feeding mechanism configured by inserting the guide member in the axial direction into a sub-valve port provided on the rotor shaft and formed in the partitioning portion and moving in the axial direction. and a needle valve that controls the opening degree of the sub-valve port, and an electrically operated valve that throttles fluid in a constriction portion between the sub-valve port and the needle valve,
The partition section includes a throttle flow path having a uniform cross-sectional area from the main valve chamber to the throttle section between the sub-valve port and the needle valve in a direction intersecting the axis; A needle guide hole is formed coaxially with the port and facing the sub-valve port,
The needle valve has a straight portion in the axial direction,
The straight part is configured to be guided along the axis in the needle guide hole,
a vertical hole connecting the auxiliary valve port and the needle guide hole in the axial direction;
The vertical hole is coaxial and has the same diameter as the sub-valve port,
The throttle channel is directly connected to the vertical hole,
The electric valve, wherein an outer diameter of the straight portion is smaller than an outer diameter of the male threaded portion. The guide member includes a press-fit portion that is press-fit into the inner circumferential surface of the valve body;
a cylindrical guide portion that is arranged in the axial direction of the press-fit portion and has a smaller diameter than the press-fit portion;
a holder portion extending to the guide portion and having a diameter equal to or less than the outer diameter of the guide portion;
The electric valve according to claim 1, wherein the female screw portion is formed at the center of the holder portion. Claim 1, wherein a cylindrical expansion hole is formed which communicates with the opening of the auxiliary valve port on the side opposite to the side where the vertical hole is located and has an inner diameter larger than the inner diameter of the auxiliary valve port. or the electric valve described in 2. The needle valve includes the straight part and a needle whose base end is continuous with the one end in the axial direction of the straight part and whose diameter is reduced toward the distal end,
A value twice the length from the proximal end to the distal end of the outer circumferential surface of the needle that forms an acute angle with the inner circumferential surface of the auxiliary valve port is greater than the outer diameter of the straight portion. The electric valve according to any one of claims 1 to 3, characterized in that: The needle valve includes the straight part and a needle whose base end is continuous with the one end in the axial direction of the straight part and whose diameter is reduced toward the distal end,
The electric valve according to any one of claims 1 to 4, wherein the length of the needle in the axial direction from the base end to the tip end is larger than the radius of the straight part. The electric valve according to any one of claims 1 to 5, wherein the needle guide hole intersects the throttle channel along the axis. A plurality of the throttle channels are formed around the axis,
7. The electric valve according to claim 6, wherein the sum of the cross-sectional areas of the plurality of throttle passages is set to be larger than the cross-sectional area of the sub-valve port. A refrigeration cycle system comprising a compressor, an indoor heat exchanger, an outdoor heat exchanger, and an electronic expansion valve, wherein the electric valve according to any one of claims 1 to 7 A refrigeration cycle system characterized by being used as a valve.

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