JP7650332B2 - 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 2017-211034 A (Patent Document 1).

The motor-operated valve of Patent Document 1 includes a main valve body (valve body 32) and a sub-valve body (valve stem 20), and performs low flow control by passing refrigerant from the communication passage (29w) of the sub-valve body through the inside of the sub-valve body to the sub-valve port (valve port 36) of the main valve body. When the main valve body is fully open, most of the fluid (refrigerant) flows into the main valve port (valve port 16), which is the gap between the main valve body and the main valve seat, but some of the fluid flows from the communication passage (29w) of the sub-valve body to the sub-valve port of the main valve body (paragraph [0050] of Patent Document 1).

As an example of this type of motor-operated valve, the one shown in Figure 7 is considered. This motor-operated valve is equipped with a main valve body c that opens and closes the main valve port b in the main valve chamber aR of the valve body a, and a sub-valve body e that controls the opening of the sub-valve port d in the sub-valve chamber cR formed in the main valve body c. This is a two-stage motor-operated valve that has a small flow control region where the main valve body c fully closes the main valve port b and the sub-valve body e controls the opening of the sub-valve port d to throttle the fluid, and a large flow region where the main valve body c fully opens the main valve port b to allow the fluid flowing in from the inlet port g of the first coupling tube f to flow to the main valve port b.

JP 2017-211034 A

In the motor-operated valve of Patent Document 1, when the main valve body is fully open (high flow rate range), part of the fluid flows from the communication passage (29w) of the sub-valve body to the sub-valve port of the main valve body, which causes disturbances in the flow rate and pressure in the valve chamber, making the flow of the fluid unstable and possibly causing noise and vibration. In addition, in the motor-operated valve shown in FIG. 7, when the main valve body c is fully open (high flow rate range), the fluid mainly passes from the main valve chamber aR between the main valve body c and the main valve port b, but there is also a flow that passes from the communication hole h provided in the main valve body c through the sub-valve chamber cR inside the main valve body c and passes between the sub-valve body e and the sub-valve port d. Therefore, the flow that is throttled through this sub-valve port d causes the behavior of the speed and pressure of the fluid flowing through the main valve port b to become unstable, which may cause vibration of the main valve body c and refrigerant passing noise.

The present invention aims to stabilize the flow of fluid through the main valve body and the main valve port during control of the large flow rate range in a two-stage motor-operated valve in which the main valve body fully closes the main valve port, and a throttle section formed on the main valve body between the sub-valve port and the sub-valve body controls the flow rate of the refrigerant in a small flow rate control range, while the main valve body fully opens the main valve port to allow fluid to flow to the main valve port, thereby suppressing noise and vibration from the motor-operated valve itself.

The motor-operated valve of the present invention comprises a main valve element provided in a main valve chamber of a valve body for opening and closing a main valve port opening into the main valve chamber, and a sub-valve element which moves in a sub-valve chamber formed in the main valve element in the axial direction of the sub-valve port formed on the main valve element to control the opening of the sub-valve port, and has a small flow rate control region in which the main valve element closes the main valve port and the sub-valve element controls the opening of the sub-valve port to throttle the fluid, and a large flow rate region in which the main valve element fully opens the main valve port and allows a fluid flowing in from an inlet port opening into the main valve chamber at a side of the main valve element to flow into the main valve port, a communication hole communicating with the auxiliary valve chamber from the inlet port is provided, and the communication holes are arranged in a position such that, when the main valve body is fully open, at least one of the communication holes located on the inlet port side is not directly opposed to the opening of the inlet port, and when the main valve body is fully open, a lower end face of at least one of the communication holes located on the inlet port side is located above an upper end face of the opening of the inlet port, so that the communication hole is located away from the front of the opening of the inlet port, and the valve body is formed in a cylindrical shape with a constant inner diameter from the inlet port to its upper end .

Furthermore, it is preferable that the motor-operated valve be characterized in that, when the main valve body is fully open, the central axis of at least one of the communication holes located on the inlet port side intersects with the central axis of the inlet port when projected onto a plane perpendicular to the axis L of the main 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, an electronic expansion valve provided between the indoor heat exchanger and the outdoor heat exchanger, and a dehumidification valve provided in the indoor heat exchanger, characterized in that the motor-operated valve is used as the dehumidification valve.

According to the motor-operated valve and refrigeration cycle system of the present invention, when the main valve body is fully open, the fluid flowing from the inlet port into the main valve chamber is not directly injected into the communication hole, so that the inflow of fluid from the communication hole into the auxiliary valve chamber can be reduced. Therefore, the flow of fluid to the main valve body and the main valve port can be stabilized, and the generation of noise and vibration from the motor-operated valve itself can be suppressed.

FIG. 2 is a vertical cross-sectional view of the motor-operated valve according to the first embodiment of the present invention in a small flow rate control range state. FIG. 2 is a vertical cross-sectional view of the motor-operated valve of the first embodiment in a large flow rate range state. 1A is an enlarged longitudinal cross-sectional view of a main portion of a motor-operated valve of a second embodiment of the present invention in a large flow rate range state, and FIG. 1B is an enlarged transverse cross-sectional view of a main portion projected onto a plane perpendicular to the axis L of the main valve port. FIG. 11 is an enlarged longitudinal sectional view of a main portion of a motor-operated valve according to a third embodiment of the present invention in a large flow rate range state. 13 is an enlarged cross-sectional view of a main portion of a fourth embodiment of the motor-operated valve of the present invention, in which a communication hole and an inlet port in a large flow rate range state are projected onto a plane perpendicular to the axis L of the main valve port. FIG. 1 is a diagram showing a refrigeration cycle system according to an embodiment of the present invention. 1 is a diagram illustrating an example of a two-stage motor-operated valve and its problems. FIG.

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 first embodiment in a small flow rate control range state, and Fig. 2 is a vertical cross-sectional view of the motor-operated valve of the first embodiment in a large flow rate range state. The concepts of "upper and lower" in the following description correspond to the upper and lower in Fig. 1 and Fig. 2. This motor-operated valve 100 includes a valve housing 1, a guide member 2, a main valve element 3, a sub-valve element 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 on its inside. A first coupling tube 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 tube 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 tube 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 tube 12 is connected to the main valve chamber 1R via the main valve port 13a. The inner end of the first coupling tube 11 on the main valve chamber 1R side is the inlet port 11a.

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 circumferential surface of the valve housing 1, a generally cylindrical upper guide portion 22 located above the press-fit portion 21, a holder portion 23 that extends above the upper portion of the upper guide portion 22, a ring-shaped flange portion 24 that is provided on the outer periphery of the press-fit portion 21, and a generally cylindrical lower guide portion 25 that is located below the press-fit portion 21. The press-fit portion 21, the upper guide portion 22, the lower guide portion 25, and the holder portion 23 are configured as an integrated resin product. The flange portion 24 is a metal plate, such as brass or stainless steel, and is formed 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 by welding to the upper end of the valve housing 1 via the flange portion 24. In addition, a cylindrical guide hole 2A coaxial with the axis L is formed inside the press-fit portion 21, upper guide portion 22, and lower guide portion 25 of the guide member 2, and a female threaded portion 23a coaxial with the guide hole 2A and its threaded hole are formed in the center of the holder portion 23. The main valve body 3 is disposed within the guide hole 2A.

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 chamber 3R is formed inside the holding portion 32, with the inner peripheral surface of this sub-valve chamber 3R serving as a sub-valve guide hole 3B. 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 from the sub-valve chamber 3R to the expansion hole 3A side.

In addition, a communication passage 3b is formed on the side surface of the holding portion 32 of the main valve body 3, which communicates from the main valve chamber 1R to the auxiliary valve chamber 3R in a direction intersecting the axis L. In this embodiment, multiple communication passages 3b (for example, four) are formed radially at positions that are rotationally symmetrical around the axis L. The four communication passages 3b are formed in positions that do not directly face the inlet port 11a, which is the opening of the first joint tube 11, in the direction of the axis L. Note that, although four communication passages 3b are shown as an example here, any number of communication passages may be formed as long as they are not directly facing the inlet port 11a.

The main valve element 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, and the main valve element 3 is biased in the direction of the main valve seat 13 (closing direction) by the main valve spring 35. The sub-valve element 4 is integrally formed with the rotor shaft 51 at the lower end of the rotor shaft 51, and the sub-valve element 4 is composed of a guide boss portion 41 and a needle valve 42. The tip of the needle valve 42 of the sub-valve element 4 is inserted into the sub-valve port 3a in the axial direction L, and a small flow rate of refrigerant flows through the gap between the needle valve 42 and the sub-valve port 3a to perform small flow rate control. An annular washer 43 made of lubricating resin is disposed at the upper end of the guide boss portion 41,
The guide boss portion 41 is slidably inserted into the sub-valve guide hole 3B.

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 facing 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 54 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, 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 communication passage 3b is located below the lower end of the lower guide portion 25 of the guide member 2, and the refrigerant in the main valve chamber 1R flows through the communication passage 3b to the sub-valve chamber 3R.

In the high flow rate state of FIG. 2, the refrigerant mainly passes from the main valve chamber 1R between the main valve portion 31 of the main valve body 3 and the main valve port 13a, but in the fully open state of this main valve body 3, the communication passage 3b is blocked by the lower guide portion 25 from the inlet port 11a. As a result, the fluid flowing into the main valve chamber 1R from the inlet port 11a is not directly injected into the communication hole 3b, so the inflow of fluid from the communication hole 3b into the auxiliary valve chamber 3R can be reduced. Therefore, the flow of fluid to the main valve body 3 and the main valve port 13a can be stabilized, vibration of the main valve body 3 is suppressed, and the generation of noise and vibration of this motor-operated valve 100 can be suppressed.

Fig. 3 is a diagram showing the motor-operated valve of the second embodiment of the present invention in the large flow rate range state, Fig. 3(A) is an enlarged longitudinal sectional view of the main part, and Fig. 3(B) is an enlarged transverse sectional view of the main part in which the communication hole and the inlet port of Fig. 3(A) are projected onto a plane perpendicular to the axis L of the main valve port. The difference from the first embodiment is that the length of the lower guide 25 of the guide member 2' opposite the inlet port 11a is shortened, while the lower guide 25 on the inlet port 11a side is longer in a predetermined width, and a rotation stopper is provided, not shown, so that the main valve body 3 does not rotate even if it moves up and down. For example, the rotation stopper may be formed by forming a key portion in an axially elongated convex shape on the inner circumference of the guide member 2', which fits into a vertically elongated concave groove formed on the outer circumference of the main valve body 3 to prevent the main valve body 3 from rotating. At the time of initial valve assembly, the position of the rotation stopper of the main valve element 3 may be set so that the communication hole 3b on the inlet port 11a side is blocked by the lower guide part on the inlet port 11a side in the high flow rate range state as shown in Fig. 3(A) and Fig. 3(B). As a result, in the second embodiment, the communication hole 3b on the inlet port 11a side is blocked by the lower guide 25 in the high flow rate range state as in the first embodiment. Therefore, the fluid flowing from the inlet port 11a into the main valve chamber 1R is not directly injected into the communication hole 3b, so that the inflow of the fluid from the communication hole 3b into the sub-valve chamber 3R can be reduced. Therefore, the flow of the fluid to the main valve element 3 and the main valve port 13a can be stabilized, the vibration of the main valve element 3 is suppressed, and the generation of noise and vibration of this motor-operated valve 100 can be suppressed.

In FIG. 3, the axis of the communication hole 3b on the inlet port 11a side is in the same direction (parallel) as the axis of the inlet port 11a as shown in FIG. 3(B), but this is not limited thereto. If the communication hole 3b on the inlet port 11a side is within a predetermined width of the lower guide 25 on the inlet port 11a side, it will be blocked, so the axis of the communication hole 3b on the inlet port 11a side may be in a direction that forms a predetermined angle with the axis of the inlet port (not shown).

Figure 4 is an enlarged cross-sectional view of the main part of the third embodiment of the present invention in the large flow rate range state. The difference from the first embodiment is that there is no guide portion below the press-fit portion 21" of the guide member 2", and in the large flow rate range state as shown in Figure 4, the communication passage 3b moves to a position that does not directly face the inlet port 11a, which is the opening of the first coupling tube 11, in the axial direction L, that is, to a position above and away from the inlet port 11a in the axial direction L. As a result, in the large flow rate range state in this third embodiment, the refrigerant mainly passes from the main valve chamber 1R between the main valve portion 31 of the main valve body 3 and the main valve port 13a, but when the main valve body 3 is fully open, the fluid flowing into the main valve chamber 1R from the inlet port 11a is not directly injected into the communication hole 3b, so that the inflow of the fluid from the communication hole 3b into the auxiliary valve chamber 3R can be reduced. Therefore, the flow of fluid through the main valve body 3 and the main valve port 13a can be stabilized, vibration of the main valve body 3 is suppressed, and the generation of noise and vibration of the motor 100 can be suppressed.

In FIG. 4, the axis of the communication hole 3b and the axis of the inlet port 11a are in the same direction, but they may be in different directions.

Figure 5 is an enlarged cross-sectional view of the main part of the fourth embodiment of the present invention, in which the communication passage 3b and the inlet port 11a in the large flow rate region state are projected onto a plane perpendicular to the axis L. The differences from the third embodiment are that the communication hole 3b on the inlet port 11a side is located within the inner diameter of the opening of the inlet port 11a in the direction of the axis L, that the axis of the communication hole 3b is not the same direction (parallel) as the axis of the inlet port 11a but intersects as shown in Figure 5, and further, although not shown, a rotation stopper is provided so that the main valve body 3 does not rotate even if it moves up and down. The rotation stopper is the same as in the second embodiment, and the angle between the axis of the communication hole 3b and the axis of the inlet port 11a does not change even if the main valve body 3 moves in the L axis direction. As a result, even if the communication hole 3b is located within the range of the inner diameter of the opening of the inlet port 11a in the axial direction L, as shown in FIG. 5, the fluid flowing into the main valve chamber 1R from the inlet port 11a is not directly injected into the communication hole 3b, so the inflow of fluid from the communication hole 3b into the sub-valve chamber 3R can be reduced. Therefore, the flow of fluid to the main valve body 3 and the main valve port 13a can be stabilized, vibration of the main valve body 3 is suppressed, and the generation of noise and vibration of this motor-operated valve 100 can be suppressed.

In the fourth embodiment, the angle α between the central axis of the communication hole 3b on the inlet port 11a side in FIG. 5 and the central axis of the inlet port 11a is preferably 45° or more and 90° or less.

FIG. 6 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 described with reference to the same 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 a first indoor heat exchanger 91 (operating as a cooler during dehumidification) and a 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 a compressor 95, a four-way valve 96, an outdoor heat exchanger 94, and an 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, forming 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 11a Inlet port 12 Second joint pipe 13 Main valve seat 13a Main valve port L Axis 2, 2', 2" Guide member 2A Guide hole 22 Upper guide portion 25 Lower guide portion 23 Holder portion 23a Female thread portion 3 Main valve body 31 Main valve portion 32 Holding portion 3a Sub-valve port 3b Communication hole 3A Sub-valve chamber 4 Sub-valve body 41 Guide boss portion 42 Needle valve 5 Drive portion 5A Stepping motor 5B Screw feed mechanism 5C Stopper mechanism 51 Rotor shaft 51a Male thread portion 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 (3)

a main valve element provided in a main valve chamber of a valve body for opening and closing a main valve port opening into the main valve chamber, and a sub-valve element moving in an axial direction of a sub-valve port formed on the main valve element within a sub-valve chamber formed on the main valve element to control an opening degree of the sub-valve port, the two-stage motor-operated valve having a small flow rate control region in which the main valve element closes the main valve port and the sub-valve element controls the opening degree of the sub-valve port to throttle a fluid, and a large flow rate region in which the main valve element fully opens the main valve port and allows a fluid flowing in from an inlet port opening into the main valve chamber at a side of the main valve element to flow into the main valve port,
The main valve body is provided with a communication hole that communicates from the main valve chamber to the sub-valve chamber,
the communication holes are provided at a position where at least one of the communication holes located on the inlet port side does not directly face an opening of the inlet port when the main valve body is fully open,
when the main valve body is fully open, a lower end surface of at least one of the communication holes located on the inlet port side is located above an upper end surface of the opening of the inlet port, so that the communication hole is located away from the front of the opening of the inlet port ,
The valve body is formed in a cylindrical shape having a constant inner diameter from the inlet port to the upper end . The motor-operated valve according to claim 1, characterized in that, when the main valve body is fully open, the central axis of at least one of the communication holes located on the inlet port side intersects with the central axis of the inlet port when projected onto a plane perpendicular to the axis L of the main valve port. A refrigeration cycle system including a compressor, an indoor heat exchanger, an outdoor heat exchanger, an electronic expansion valve provided between the indoor heat exchanger and the outdoor heat exchanger, and a dehumidification valve provided in the indoor heat exchanger, characterized in that the motor-operated valve according to claim 1 or 2 is used as the dehumidification valve.

Images