JP7581461B2 - Motor-operated valve and refrigeration cycle system - Google Patents

Description

The present invention relates to an electrically operated valve for use in a refrigeration cycle system and a refrigeration cycle system.

Conventionally, motorized valves that control flow rate in a small flow rate control range and a large flow rate control range are used in the refrigeration cycle of air conditioners. Such motorized valves are used in indoor units (e.g., dehumidification valves), and are disclosed, for example, in JP 2019-132347 A (Patent Document 1).

JP 2019-132347 A

In this type of motor-operated valve, the small flow control range is used for dehumidification, for example. In this small flow control range, the main valve port of the main valve seat is fully closed by the main valve body, and the refrigerant passes through a throttling section between the sub-valve port formed on the main valve body and the needle valve (sub-valve body). However, in the above-mentioned conventional motor-operated valve, in the small flow control range, the fluid flows from the valve chamber (main valve chamber) through the introduction hole into the sub-valve chamber, and the fluid flows out from the throttling section between the sub-valve port and the sub-valve body through the sub-valve chamber. Therefore, the fluid flowing from the main valve chamber to the throttling section is expanded once when it flows from the introduction hole into the sub-valve chamber. This causes a problem that the sub-valve body vibrates due to pressure fluctuations of the refrigerant in the sub-valve chamber, generating noise.

The objective of the present invention is to improve quietness in the small flow control range of an electric valve having a two-stage flow control range in which the main valve body is seated on the main valve seat and the flow rate of the refrigerant is controlled in the small flow control range by a throttling section between the auxiliary valve port and the needle valve formed on the main valve body.

The motor-operated valve of the present invention comprises a valve body having a main valve chamber, a partition section which partitions a space within the main valve chamber, a rotor shaft having a male thread formed on its outer periphery, a guide member which is installed on the valve body and has a female thread section into which the male thread section screws, and a needle valve which is axially inserted into an auxiliary valve port which is provided on the rotor shaft and formed in the partition section and which moves in the axial direction by a screw feed mechanism constituted by the male thread section and the female thread section to control the opening degree of the auxiliary valve port, and in this motor-operated valve which throttles a fluid at a throttle section between the auxiliary valve port and the needle valve, the partition section has a groove extending from the main valve chamber to the groove which intersects with the axis. a throttle flow passage having a uniform flow passage cross-sectional area in a direction extending from the auxiliary valve port to the throttle section between the auxiliary valve port and the needle valve, and a needle guide hole coaxial with the auxiliary valve port and facing the auxiliary valve port, the needle valve has a straight portion in the axial direction and is configured so that the straight portion is guided on the axis by the needle guide hole, and is provided with a vertical hole connecting the auxiliary valve port and the needle guide hole in the axial direction, the vertical hole being coaxial with and having the same diameter as the auxiliary valve port, the throttle flow passage being directly connected to the vertical hole, and the inner diameter of the vertical hole being smaller than the outer diameter of the male threaded portion.
In addition, it is preferable that the vertical hole is coaxial with and has the same diameter as the auxiliary valve port and the needle guide hole.

In addition, in this case, the guide member preferably has a press-fit portion that is press-fitted into the inner peripheral surface of the valve body, a cylindrical guide portion aligned with the press-fit portion in the axial direction and having a smaller diameter than the press-fit portion, and a holder portion that is extended from the guide portion and has an outer diameter equal to or smaller than the guide portion, and the female thread portion is preferably formed in the center of the holder portion.

In addition, it is preferable that a cylindrical expansion hole is formed which communicates with an opening on the opposite side to the side where the vertical hole is located of the auxiliary valve port and has an inner diameter larger than the inner diameter of the auxiliary valve port, and that the expansion hole is formed further toward the lower end of the valve body than the main valve chamber when the main valve port of the main valve chamber is closed .

The needle valve further comprises the straight portion and a needle whose base end is connected to one axial end of the straight portion and whose diameter is reduced toward the tip end, and it is preferable that twice the length from the base end to the tip end on the outer peripheral surface of the needle, which forms an acute angle with the inner peripheral surface of the auxiliary valve port, is greater than the outer diameter of the straight portion.

The needle valve further includes the straight portion and a needle having a base end portion connected to one end portion of the straight portion in the axial direction and a diameter reduced toward a tip end portion,
It is preferable that the length of the needle in the axial direction from the base end to the tip end be greater than the radius of the straight portion.

It is also preferable that the needle guide hole intersects with the throttle flow passage along the axis.

It is also preferable that a plurality of the throttle passages are formed around the axis, and the sum of the flow passage cross-sectional areas of the plurality of throttle passages is set to be larger than the flow passage cross-sectional area of the auxiliary valve port.

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 is characterized in that any of the motor-operated valves described above is used as the electronic expansion valve.

According to the motor-operated valve and refrigeration cycle system of the present invention, in a state of small flow rate control by the throttling section (gap) between the sub-valve body and the sub-valve port, the fluid from the main valve chamber to the throttling section passes only through a throttling passage with a uniform flow cross-sectional area, suppressing refrigerant pressure fluctuations and stabilizing the state of the refrigerant, and the needle valve is guided to the immediate vicinity of the sub-valve port by the needle valve guide hole, thereby suppressing vibration of the sub-valve body, and furthermore, noise reduction is improved by providing a sound-absorbing member at the opening on the valve chamber side of the throttling passage of the main valve body and/or the opening of the expansion hole.

FIG. 2 is a vertical cross-sectional view of the motor-operated valve according to the embodiment of the present invention in a small flow rate control range state. 2 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve according to the embodiment in a state in which the sub-valve body is slightly raised from the small flow rate control region state of FIG. 1 . FIG. FIG. 4 is an enlarged view showing a modified example of the main valve body in the motor-operated valve of the embodiment. 1 is a diagram showing a refrigeration cycle system according to an embodiment of the present invention.

Next, an embodiment of the motor-operated valve and refrigeration cycle system of the present invention will be described with reference to the drawings. Fig. 1 is a vertical cross-sectional view of the motor-operated valve of the embodiment in a small flow control range state, and Fig. 2 is an enlarged vertical cross-sectional view of the main parts of the motor-operated valve of the embodiment in a state where the sub-valve body is slightly raised from the small flow control range state of Fig. 1. The concepts of "up and down" in the following description correspond to up and down in Figs. 1 and 2. This motor-operated valve 100 comprises a valve housing 1, a guide member 2, a main valve body 3, a sub-valve body 4, and a drive unit 5.

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

A guide member 2 is attached to the opening at the upper end of the valve housing 1. The guide member 2 has a press-fit portion 21 that is press-fitted into the inner peripheral surface of the valve housing 1, approximately cylindrical guide portions 22, 23 that are smaller in diameter than the press-fit portion 21 and are located above and below the press-fit portion 21, a holder portion 24 that extends from the upper portion of the upper guide portion 22, and a ring-shaped flange portion 25 that is provided on the outer periphery of the press-fit portion 21. The press-fit portion 21, guide portions 22, 23, and holder portion 24 are configured as an integrated resin product. The flange portion 25 is a metal plate, such as brass or stainless steel, and is provided integrally with the resin press-fit portion 21 by insert molding.

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

The main valve body 3 is composed of a main valve portion 31 that seats and unseats on the main valve seat 13, and a holding portion 32 that holds the sub-valve body 4. A cylindrical expansion hole 3A is formed inside the main valve portion 31, and a cylindrical sub-valve guide hole 3B is formed inside the holding portion 32. A cylindrical sub-valve port 3a is formed between the main valve portion 31 and the holding portion 32, centered on the axis L and opening toward the expansion hole 3A, and a cylindrical needle guide hole 3b is formed coaxially with the axis L on the sub-valve guide hole 3B side.

In addition, at the connection between the main valve portion 31 and the holding portion 32 of the main valve body 3, a throttle passage 3c is formed that communicates from the main valve chamber 1R to a throttle portion C (FIG. 2) between the sub-valve port 3a and the needle valve 42 described later in a direction intersecting the axis L. This throttle passage 3c has a cylindrical shape such that the flow passage cross-sectional area is uniform from the main valve chamber 1R side to the sub-valve port 3a side. In this embodiment, multiple throttle passages 3c (for example, four) are formed radially at positions that are rotationally symmetrical around the axis L. The total flow passage cross-sectional area of the four throttle passages 3c is set to be larger than the flow passage cross-sectional area of the sub-valve port 3a. Note that the "flow passage cross-sectional area" is the cross-sectional area of a plane perpendicular to the direction in which the fluid flows. Note that, although four throttle passages 3c are illustrated here, two or more throttle passages may be used as long as the sum of the flow passage cross-sectional areas of the throttle passages 3c is set to be larger than the flow passage area of the sub-valve port 3a.

The main valve body 3 has a retainer 34 at the upper end of the holding portion 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. The main valve spring 35 biases the main valve body 3 toward the main valve seat 13 (closing 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 is composed of a guide boss portion 41 and a needle valve 42. 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 axial direction L, and the needle valve 42 is composed of a straight portion 42a made of a cylinder with the axial line L as the center line, and a needle 42b whose diameter is reduced toward the tip side. The outer diameter of the straight portion 42a is slightly smaller than the inner diameter of the sub-valve port 3a, and a throttle portion C (a portion surrounded by a dashed line circle) is formed between the straight portion 42a and the sub-valve port 3a, or between the needle 42b and the sub-valve port 3a. A small flow rate of refrigerant flows through this throttle portion C, thereby performing small flow rate control. In addition, an annular washer 43 made of lubricating resin is disposed on the upper end of the guide boss 41, and the washer 43 and the guide boss 41 are slidably inserted into the auxiliary valve guide hole 3B.

Furthermore, the straight portion 42a of the needle valve 42 is slidably guided on the inner circumference of the needle guide hole 3b, which intersects with the throttle passage 3c along the axis L near directly above the auxiliary valve port 3a.

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

The stepping motor 5A is composed of a rotor shaft 51, a magnet rotor 52 rotatably arranged inside the case 14, a stator coil 53 arranged opposite the magnet rotor 52 on the outer periphery of the case 14, and other yokes and exterior members (not shown). The rotor shaft 51 is attached to the center of the magnet rotor 52 via a bush, and a male screw portion 51a is formed on the outer periphery of the rotor shaft 51 on the guide member 2 side. This male screw portion 51a is screwed into the female screw portion 24a of the guide member 2, so that the guide member 2 supports the rotor shaft 51 on the axis L. The female screw portion 24a of the guide member 2 and the male screw portion 51a of the rotor shaft 51 form the screw feed mechanism 5B. In addition, 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 arranged inside this 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 rotor shaft 51 moves in the axial direction L together with the magnet rotor 52 due to the screw feed mechanism 5B between the male thread 51a of the rotor shaft 51 and the female thread 24a of the guide member 2. Then, the sub-valve body 4 moves forward and backward in the axial direction L, and the needle valve 42 approaches or moves away from the sub-valve port 3a. 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. In addition, a protrusion 52a is formed on the magnet rotor 52, and as the magnet rotor 52 rotates, the protrusion 52a activates the rotation stopper mechanism 5C, restricting the lowest end position and the highest end position of the rotor shaft 51 (and the magnet rotor 52).

In the low flow control range state of FIG. 1, the main valve element 3 is seated on the main valve seat 13 and the main valve port 13a is closed, and the needle valve 42 of the sub-valve element 4 controls the opening of the sub-valve port 3a to control the low flow rate. At this time, the refrigerant in the main valve chamber 1R flows through the throttle passage 3c to the throttle section C, and this refrigerant flows to the throttle section C at a stable pressure due to the uniform flow cross-sectional area of the throttle passage 3c. This refrigerant is then expanded when it flows out of the throttle section C into the expansion hole 3A. In other words, the flow of the refrigerant is stable from the main valve chamber 1R until it passes through the throttle section C, so vibrations in the motor-operated valve can be prevented.

In addition, since the multiple throttle channels 3c are arranged in rotationally symmetrical positions around the axis L, the refrigerant passing through the throttle channels 3c is prevented from applying a large biased force to the needle valve 42 in a direction intersecting the axis L. Furthermore, since the straight portion 42a of the needle valve 42 is guided by the needle guide hole 3b immediately above the sub-valve port 3a, vibration of the sub-valve body 4 due to the flow of refrigerant is further suppressed.

The needle 42b of the needle valve 42 advances and retreats relative to the sub-valve port 3a, but the flow path cross-sectional area of the throttle section C, which is the gap between the outer periphery of the needle 42b and the sub-valve port 3a, is always smaller than the total flow path cross-sectional area of the multiple throttle channels 3c. This allows the sub-valve body 4 to perform low flow control with high precision without being affected by the throttle channels 3c.

Figure 3 is an enlarged longitudinal cross-sectional view of the main part of the motor-operated valve in the small flow control region, showing a modified example of the motor-operated valve of the embodiment. In this modified example, the overall configuration of the motor-operated valve other than its characteristic parts is the same as in Figures 1 and 2. In this modified example, in the main valve body 3', the main valve section 31 and the holding section 32 are constructed as separate parts, a sound-absorbing member 36 is disposed at the opening of the expansion hole 3A of the main valve section 31, and a sound-absorbing member 37 is disposed at the opening of the main valve chamber 1R side of the throttle flow passage 3c at the connecting section between the holding section 32 and the main valve section 31. These sound-absorbing members 36, 37 absorb the sound of the refrigerant passing through, further enhancing the silencing effect. Note that only one of the sound-absorbing members 36, 37 may be used.

Figure 4 shows a refrigeration cycle system according to an embodiment of the present invention, and the refrigeration cycle system according to the embodiment will be described based on this figure. The refrigeration cycle system is used, for example, in an air conditioner such as a home air conditioner. The motor-operated valve 100 according to the embodiment is provided between the first indoor heat exchanger 91 (operating as a cooler during dehumidification) and the second indoor heat exchanger 92 (operating as a heater during dehumidification) of the air conditioner, and constitutes a heat pump type refrigeration cycle together with the compressor 95, the four-way valve 96, the outdoor heat exchanger 94, and the electronic expansion valve 93. The first indoor heat exchanger 91, the second indoor heat exchanger 92, and the motor-operated valve 100 are installed indoors, and the compressor 95, the four-way valve 96, the outdoor heat exchanger 94, and the electronic expansion valve 93 are installed outdoors to constitute a heating and cooling device.

In the embodiment of the motor-operated valve 100 as a dehumidification valve, during cooling or heating other than dehumidification, the main valve body is fully open, and the first indoor heat exchanger 91 and the second indoor heat exchanger 92 are made into a single indoor heat exchanger. The combined indoor heat exchanger and outdoor heat exchanger 94 function alternatively as an "evaporator" and a "condenser". In other words, the motor-operated valve 93 as an electronic expansion valve is provided between the evaporator and the condenser.

The present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and the following modifications are also included in the present invention. For example, the above-described embodiment illustrates an electric valve 100 used in an air conditioner such as a home air conditioner, but the electric valve of the present invention is not limited to home air conditioners, but may also be used in commercial air conditioners, and is not limited to air conditioners, but can also be applied to various types of refrigeration machines, etc.

The above describes the embodiments of the present invention 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, and the present invention also includes design changes that do not deviate from the gist of 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 section 2 Guide member 2A Guide hole 24 Holder section 24a Female thread section 3 Main valve body 31 Main valve section 32 Holding section 3a Sub-valve port 3b Needle guide hole 3c Throttle flow passage 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 section 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 Motor-operated valve

Claims (9)

an electrically operated valve comprising: a valve body having a main valve chamber; a partition section which partitions a space within the main valve chamber; a rotor shaft having a male thread section formed on its outer periphery; a guide member which is installed on the valve body and has a female thread section which screws into said male thread section; and a needle valve which is axially inserted into an auxiliary valve port which is provided on the rotor shaft and formed in the partition section and which moves in the axial direction by a screw feed mechanism constituted by said male thread section and said female thread section to control the opening of said auxiliary valve port, and which throttles a fluid at a throttle section between said auxiliary valve port and said needle valve,
the partition portion is formed with a throttle flow passage having a uniform flow passage cross-sectional area in a direction intersecting with the axis from the main valve chamber to the throttle portion between the sub-valve port and the needle valve, and a needle guide hole that is coaxial with the sub-valve port and faces the sub-valve port,
The needle valve has a straight portion in the axial direction,
The straight portion is configured to be guided along the axis by the needle guide hole,
a vertical hole that connects the auxiliary valve port and the needle guide hole in the axial direction,
The vertical hole is coaxial with and has the same diameter as the secondary valve port,
The throttle channel is directly connected to the vertical hole,
An electrically operated valve, characterized in that an inner diameter of the vertical hole is smaller than an outer diameter of the male threaded portion. 2. The motor-operated valve according to claim 1, wherein the vertical hole is coaxial with and has the same diameter as the auxiliary valve port and the needle guide hole. The guide member has a press-fit portion that is press-fitted into an inner circumferential surface of the valve body,
a cylindrical guide portion that is aligned with the press-fit portion in the axial direction and has a smaller diameter than the press-fit portion;
a holder portion that is extended from the guide portion and has an outer diameter equal to or smaller than the outer diameter of the guide portion,
3. The motor-operated valve according to claim 1, wherein the female thread is formed at the center of the holder. a cylindrical expansion hole is formed , the expansion hole having an inner diameter larger than an inner diameter of the auxiliary valve port and communicating with an opening on the opposite side to the side where the vertical hole is located of the auxiliary valve port;
4. The motor-operated valve according to claim 1, wherein the expansion hole is formed further to a lower end side of the valve body than the main valve chamber when a main valve port of the main valve chamber is closed . the needle valve includes the straight portion and a needle having a base end portion connected to one end portion in the axial direction of the straight portion and a diameter reduced toward a tip end portion,
The motor-operated valve according to any one of claims 1 to 4, characterized in that twice the length from the base end to the tip end on the outer peripheral surface of the needle, which forms an acute angle with the inner peripheral surface of the auxiliary valve port, is greater than the outer diameter of the straight portion. the needle valve includes the straight portion and a needle having a base end portion connected to one end portion in the axial direction of the straight portion and a diameter reduced toward a tip end portion,
The motor-operated valve according to any one of claims 1 to 5 , characterized in that a length of the needle in the axial direction from the base end to the tip end is larger than a radius of the straight portion. The motor-operated valve according to any one of claims 1 to 6 , wherein the needle guide hole intersects with the throttle passage along the axis. The throttle flow passage is formed in plurality around the axis line,
8. The motor-operated valve according to claim 7 , wherein a sum of the flow passage cross-sectional areas of the plurality of throttle passages is set to be larger than a flow passage cross-sectional area of the sub-valve port. A refrigeration cycle system including a compressor, an indoor heat exchanger, an outdoor heat exchanger, and an electronic expansion valve, wherein the motor-operated valve according to any one of claims 1 to 8 is used as the electronic expansion valve.

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