Motor-operated valve and refrigeration cycle system

Abstract

To improve controllability in a small flow rate area by preventing vibration of a main valve element in a small flow rate control area, in a motor-operated valve having two-stage flow rate control areas in which a main valve port of a main valve seat is kept in a fully closed state by a main valve element, and flow rate control in the small flow rate control area, of a refrigerant is performed by a throttle portion between an auxiliary valve port formed on the main valve element and a needle valve.SOLUTION: A main valve port 13a is kept in a fully closed state by a main valve element 3, and a fluid flows in a throttle portion (clearance) between a needle portion 42 of a needle valve 4 and an auxiliary valve port 33a to define a small flow rate control area. In the small flow rate control area, a tapered portion 41a (contact portion) of the needle valve 4 (auxiliary valve element) is brought into contact with a step portion 3a (contact portion) of the main valve element 3. By the contact of the taper portion 41a and the step portion 3a, the main valve element 3 is pressed toward a main valve seat 13 side by the needle valve 4.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a motor-operated valve for use in a refrigeration cycle system and the like, and to a refrigeration cycle system. [Background technology]

[0002] Conventionally, there is a motor-operated valve that controls flow rate in a small flow rate control region and a large flow rate control region as a motor-operated valve provided in the refrigeration cycle of an air conditioner. Such a motor-operated valve has applications (e.g., a dehumidification valve) mounted on an indoor unit, and is disclosed, for example, in JP 2019-132347 A (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-132347 A Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of motor-operated valve, the small flow rate control region is used for, for example, dehumidification operation, and in this small flow rate control region, the main valve port of the main valve seat is fully closed by the main valve body, and the refrigerant passes through a throttle section between the sub-valve port formed on this main valve body and the needle valve (sub-valve body). However, there is a problem that pressure changes and piping vibrations occur due to pulsation of the refrigerant flow on the primary or secondary side, causing the main valve body to vibrate and reducing controllability in the small flow rate region.

[0005] The present invention aims to prevent vibration of the main valve body in the small flow rate control range and improve controllability in the small flow rate range in an electric valve having a two-stage flow rate control range in which the main valve body is seated on the main valve seat and the flow rate of refrigerant in the small flow rate control range is controlled by a throttling section between this main valve body and the main valve seat, and by a throttling section between a sub-valve port formed in the main valve body and a needle valve. [Means for solving the problem]

[0006] The motor-operated valve of the present invention is a two-stage motor-operated valve including a main valve body adjacent to or separated from a main valve seat formed on the periphery of a main valve port provided in a main valve chamber of a valve housing, and a sub-valve body adjacent to or separated from a sub-valve seat formed on the periphery of a sub-valve port provided in a sub-valve chamber inside the main valve body, and the sub-valve body and the main valve body are not directly connected to each other. 、 or , through a coil spring The sub-valve body has a straight portion formed of a cylinder having a center line that coincides with the axis of the valve housing, and an outer diameter of the straight portion is smaller than an inner diameter of the sub-valve port. Shape The main valve body is seated on the main valve seat. In a state where the sub-valve body presses the main valve body in the center line direction at the abutment portion, The straight portion One end side At least a portion of the secondary valve port is located within the secondary valve port. and an edge portion of the inner opening edge portion of the introducing hole closest to the auxiliary valve port is located between one end portion of the straight portion and the other end portion of the straight portion in the center line direction. It is characterized by the fact that

[0007] The motor-operated valve of the present invention is a two-stage motor-operated valve including a main valve body adjacent to or separated from a main valve seat formed on the periphery of a main valve port provided in a main valve chamber of a valve housing, and a sub-valve body adjacent to or separated from a sub-valve seat formed on the periphery of a sub-valve port provided in a sub-valve chamber inside the main valve body, and the sub-valve body and the main valve body are directly connected to each other. 、 or , through a coil spring the sub-valve body has a straight portion formed of a cylinder having a center line that coincides with the axis of the valve housing, the straight portion having an outer diameter smaller than an inner diameter of the sub-valve port, the main valve body closes the main valve port, In a state where the sub-valve body presses the main valve body in the center line direction at the abutment portion, a first throttle portion formed between the straight portion and the auxiliary valve port, the first throttle portion being provided with a small flow rate control region state in which the flow rate is controlled by the first throttle portion; Shape In the small flow rate control region state, At least one end A portion of the valve is located within the secondary valve port. and an edge portion of the inner opening edge portion of the introducing hole closest to the auxiliary valve port is located between one end portion of the straight portion and the other end portion of the straight portion in the center line direction. It is characterized by:

[0009] Also, In the center line direction, Between the abutment portion and the auxiliary valve port To, The straight portion and the introducing hole are located, The through hole and the auxiliary valve port are in communication with each other. It is preferable.

[0010] In addition, it is preferable that the sub-valve body is configured to press the main valve body against the main valve seat when a first throttling portion consisting of a radial gap between the straight portion and the sub-valve port is formed.

[0011] It is also preferable that the sub-valve body comprises the abutment portion and a needle portion, and the needle portion comprises the straight portion and a needle that narrows in diameter toward the main valve port side and is connected to the main valve port side of the straight portion.

[0012] It is also preferable that at least one of the contact portions between the sub-valve element and the main valve element is a step portion.

[0013] 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, and is characterized in that the electric valve is used as the dehumidification valve. Effect of the Invention

[0014] According to the electric valve and refrigeration cycle system of the present invention, in a state of small flow rate control by the throttling portion (gap) between the sub-valve element and the sub-valve port, or by the throttling portion between the main valve element and the main valve seat, or between the sub-valve element and the sub-valve seat, the abutment portion between the sub-valve element and the main valve element (including the case where a spring is disposed between the sub-valve element and the main valve element) abuts, and the sub-valve element presses the main valve element against the main valve seat. Therefore, even if a pressure change of the fluid at the main valve port or piping vibration occurs, the main valve element does not vibrate, and controllability in the small flow rate range is improved. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a vertical sectional view of the motor-operated valve according to the first embodiment of the present invention in a small flow rate control range state. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the motor-operated valve of the first embodiment in a fully open state of a main valve body when the valve is stopped or in a cooling operation. [Diagram 3] FIG. 2 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the first embodiment in a small flow rate control range state. [Figure 4] FIG. 11 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the second embodiment in a small flow rate control range state. [Diagram 5] 13A and 13B are diagrams showing Example 1 and Example 2 of a second throttle portion in the second embodiment. [Figure 6] FIG. 4 is an enlarged view of a needle portion and an auxiliary valve port in a small flow rate control range state of the motor-operated valve of the first and second embodiments. [Figure 7] FIG. 13 is a diagram showing a modification of the first and second embodiments. [Figure 8] FIG. 11 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the third embodiment in a small flow rate control range state. [Figure 9] FIG. 11 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the fourth embodiment in a small flow rate control range state. [Figure 10] FIG. 13 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the fifth embodiment in a small flow rate control range state. [Figure 11] FIG. 13 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the sixth embodiment in a small flow rate control range state. [Figure 12] 1 is a diagram showing a refrigeration cycle system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] 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 control range state, Fig. 2 is a vertical cross-sectional view of the motor-operated valve of the first embodiment in a fully open state of the main valve body when the operation is stopped or during cooling operation, and Fig. 3 is an enlarged vertical cross-sectional view of the main part of the motor-operated valve of the first embodiment in a small flow control range state. The concepts of "upper and lower" in the following description correspond to the upper and lower in Figs. 1 and 2. This motor-operated valve 100 includes a valve housing 1, a guide member 2, a main valve body 3, a needle valve 4 as an "auxiliary valve body", and a drive unit 5.

[0017] The valve housing 1 is formed in a substantially cylindrical shape from brass, stainless steel, or the like, and has a main valve chamber 1R inside. A first joint 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 joint pipe 12 is connected to a cylindrical portion extending downward from the lower end. A cylindrical 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, and the second joint pipe 12 is connected to the main valve chamber 1R via the main valve port 13a. The main valve port 13a is a cylindrical through hole (through hole) centered on the axis L. The first joint pipe 11 and the second joint pipe 12 are fixed to the valve housing 1 by brazing or the like.

[0018] 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 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, the guide portions 22, 23, and the 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 flange portion 25 is provided with a hole (not shown) that communicates between the main valve chamber 1R and the inside of the case 14 described later in the direction of the axis L of the valve shaft.

[0019] 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 25. In the guide member 2, 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, 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 element 3 is disposed inside the lower guide portion 23 and in the guide hole 2A.

[0020] The main valve body 3 has a main valve portion 31 that is seated on and released from the main valve seat 13, a holding portion 32 having a cylindrical needle guide hole 32a, an auxiliary valve seat 33 that constitutes the bottom of the needle guide hole 32a, and a retainer 34 provided at the end of the holding portion 32. In addition, below the needle guide hole 32a, an auxiliary valve chamber 3R that is connected to the needle guide hole 32a is formed, and a step portion 3a is formed as an "abutment portion" at the boundary between the auxiliary valve chamber 3R and the needle guide hole 32a. A washer 43 attached to a rotor shaft 51 (described later) and a guide boss portion 41 of the needle valve 4 formed integrally with the rotor shaft 51 are inserted into the needle guide hole 32a of the holding portion 32. The ring-shaped retainer 34 is fixed to the upper end of the holding portion 32 by fitting or welding.

[0021] A main valve spring 35 is disposed between the retainer 34 and the upper end of the guide hole 2A, and the main valve element 3 is biased in the direction (closing direction) towards the main valve seat 13. A cylindrical sub-valve port 33a centered on the axis L is formed in the center of the sub-valve seat 33. A through hole 32b that communicates between the sub-valve chamber 3R and the main valve chamber 1R is formed in one location on the side surface of the retaining portion 32 below the step portion 3a, and when the needle valve 4 serving as the sub-valve element opens the sub-valve port 33a, the main valve chamber 1R, the sub-valve chamber 3R, the sub-valve port 33a and the main valve port 13a communicate with each other. Furthermore, the main valve chamber 1R and the interior of the case 14 are connected by a hole (not shown) provided in the flange portion 25 that communicates in the direction of the axis L of the valve shaft, the interior of the case 14 and the interior of the guide member 2 are connected by a communication hole provided in the upper part of the guide member 2, and the upper part of the main valve body 3 and the space directly above the step portion 3a of the main valve body 3 are connected by the outer periphery of the washer 43 and the gap between the outer periphery of the guide boss portion 41 of the needle valve 4 and the inner periphery of the needle guide hole 32a of the main valve body 3, thereby connecting the main valve chamber 1R and the auxiliary valve chamber 3R.

[0022] The needle valve 4 as the "auxiliary valve element" is integrally attached to the lower end of the rotor shaft 51. The needle valve 4 is formed with a guide boss 41 and a needle 42. The guide boss 41 has a tapered portion 41a as a truncated cone-shaped "contact portion" whose diameter gradually decreases toward the needle 42, and the tapered portion 41a is capable of contacting a step 3a (contact portion) of the main valve body 3. The needle 42 is connected to the end of the tapered portion 41a. An annular washer 43 made of a lubricating resin is disposed on the upper end of the guide boss 41. The washer 43 and the guide boss 41 are slidably inserted into the needle guide hole 32a.

[0023] A case 14 is airtightly fixed to the upper end of the valve housing 1 by welding or the like, and a 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 needle valve 4 back and forth by the rotation of the stepping motor 5A, and a stopper mechanism 5C that regulates the rotation of the stepping motor 5A.

[0024] The stepping motor 5A is composed of a rotor shaft 51, a magnet rotor 52 rotatably disposed inside the case 14, a stator coil 53 disposed facing the magnet rotor 52 on the outer periphery of the case 14, and other components such as a yoke 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 thread portion 51a is formed on the outer periphery of the rotor shaft 51 on the guide member 2 side. The male thread portion 51a is screwed into the female thread portion 24a of the guide member 2, so that the guide member 2 supports the rotor shaft 51 on the axis L. The female thread portion 24a of the guide member 2 and the male thread portion 51a of the rotor shaft 51 constitute a screw feed mechanism 5B. In addition, a coil spring 55 is arranged within cylindrical portion 14a, which holds rotation stopper mechanism 5C on the inner ceiling of case 14, via a spring receiver 54 that abuts against the upper end of rotor shaft 51. This coil spring 55 urges rotor shaft 51 downward, thereby preventing backlash in screw feed mechanism 5B.

[0025] 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 together with the magnet rotor 52 in the axial direction L 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 needle valve 4 moves forward and backward in the axial direction L, and the needle valve 4 approaches or moves away from the sub-valve port 33a. When the needle valve 4 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 needle valve 4 and leaves the main valve seat 13. 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, and the lowest and highest positions of the rotor shaft 51 (and the magnet rotor 52) are restricted.

[0026] In the small flow rate control range state in 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 4 controls the opening of the sub-valve port 33a to control the small flow rate. For example, when the compressor of the refrigeration cycle system is stopped and the fluid (refrigerant) is stopped, if the needle valve 4 and the main valve element 3 rise, the main valve port 13a is fully opened as shown in Fig. 2. As a result, a large flow rate of the fluid (refrigerant) flows from the first joint pipe 11 to the second joint pipe 12 during cooling operation, and a large flow rate of the fluid (refrigerant) flows from the second joint pipe 12 to the first joint pipe 11 during heating operation.

[0027] As shown in FIG. 3, the needle portion 42 is composed of a straight portion 42a made of a cylinder with the axis L as the center line, and a needle 42b whose diameter tapers toward the tip side. The outer diameter of the straight portion 42a is smaller than the inner diameter of the sub-valve port 33a, and a first throttle portion (gap) is formed between the straight portion 42a and the sub-valve port 33a. A constant flow rate of refrigerant flows through this first throttle portion, thereby performing low flow rate control. In this low flow rate control state, the tapered portion 41a of the guide boss portion 41 of the needle valve 4 contacts the main valve body 3. At this time, the needle valve 4 presses the main valve element 3 toward the main valve seat 13 due to the biasing force of the anti-backlash coil spring 55. Therefore, even if a change in fluid pressure occurs between the main valve chamber 1R and the main valve port 13a, the main valve element 3 does not vibrate, improving controllability in the small flow rate range.

[0028] FIG. 4 is an enlarged longitudinal sectional view of a main portion of the motor-operated valve of the second embodiment in a small flow rate control range state, FIG. 5 is a diagram showing examples 1 and 2 of the second throttling portion in the second embodiment, FIG. 6 is an enlarged view of the needle portion and auxiliary valve port in a small flow rate control range state of the motor-operated valves of the first and second embodiments, and FIG. 7 is a diagram showing a modified example of the motor-operated valves of the first and second embodiments. In each of the following embodiments and modified examples, the overall configuration of the motor-operated valve is the same as in FIGS. 1 and 2.

[0029] 4 is similar to the first embodiment in that a first throttle portion is formed between the straight portion 42a of the needle portion 42 and the sub-valve port 33a, and in the state of small flow rate control, the tapered portion 41a of the needle valve 4 abuts against and presses the stepped portion 3a of the main valve element 3, preventing the main valve element 3 from vibrating and improving controllability in the small flow rate range. In addition, in the second embodiment, a second throttle portion P is formed between the main valve element 3 and the main valve seat 13.

[0030] In the first embodiment of Fig. 5(A), a groove 6 is formed as a "second throttle portion P" on the opening edge of the main valve port 13a in the main valve seat 13. The groove 6 acts to cause the refrigerant to flow from the main valve chamber 1R to the main valve port 13a even when small flow rate control is performed by the first throttle portion between the sub-valve port 33a and the straight portion 42a of the needle portion 42. Therefore, the pressure difference before and after the throttle portion between the sub-valve port 33a and the needle portion 42 is reduced, and the refrigerant passing sound at this throttle portion can be reduced.

[0031] In the second embodiment of Fig. 5(B), a groove 6' is formed as a "second throttle portion P" in the main valve portion 31 of the main valve 3. As in the first embodiment, the groove 6' allows the refrigerant to flow from the main valve chamber 1R to the main valve port 13a even when a small flow rate control is performed by the first throttle portion between the sub-valve port 33a and the straight portion 42a of the needle portion 42. Therefore, the pressure difference between the front and rear of the throttle portion between the sub-valve port 33a and the needle portion 42 is reduced, and the refrigerant passing sound at this throttle portion can be reduced.

[0032] As shown in FIG. 6, the needle portion 42 is composed of a straight portion 42a made of a thin cylinder with the axis 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 smaller than the inner diameter of the sub-valve port 33a, and a first throttling portion (gap) is formed between the straight portion 42a and the sub-valve port 33a. A constant flow rate of refrigerant flows through this first throttling portion, thereby performing low flow rate control. During this low flow rate control, the pressure of the refrigerant flowing into the straight portion 42a and the throttling portion of the sub-valve port 33a is dispersed around the axis L by a groove 6 (second throttling portion) formed on the sub-valve chamber 3R side of the sub-valve port 33a, reducing the pressure difference before and after the first throttling portion composed of the sub-valve seat 33 and the needle portion 42, thereby reducing the refrigerant passing sound at the first throttling portion.

[0033] In the modified example of FIG. 7, a groove 4a is formed as a "second throttle portion" in the needle portion 42. The groove 4a is formed from the root portion 42c of the needle portion 42 on the guide boss portion 44 side to the middle of the straight portion 42a. A plurality of grooves 4a (six in this example) are formed, and the grooves 4a are formed at rotationally symmetric positions with respect to the axis L at equal intervals (every 60°) around the axis L. Furthermore, the area of ​​the horizontal cross section of the groove 4a becomes smaller as it approaches the auxiliary valve port 33a in the direction of the axis L. In this modified example, the groove 4a is formed only to the middle of the straight portion 42a, so that the opening area of ​​the throttle portion between the straight portion 42a and the auxiliary valve port 33a is constant as in the embodiment, and the flow rate during small flow rate control can be kept constant.

[0034] Also in this modified example, during low flow control, the pressure of the refrigerant flowing into the straight portion 42a and the throttling portion of the sub-valve port 33a is dispersed around the axis L by the groove 4a formed in the needle portion 42, reducing the pressure difference before and after the throttling portion formed by the sub-valve seat 33 and the needle portion 42, thereby reducing the refrigerant passing noise in this throttling portion.

[0035] FIG. 8 is an enlarged longitudinal sectional view of the main part of the motor-operated valve of the third embodiment in the small flow control region state. The difference between the third embodiment and the first embodiment is the structure of the needle valve 4' as the "sub-valve body". The needle valve 4' of the third embodiment is composed of a thin guide boss portion 41' formed integrally with the rotor shaft 51, a needle portion 42 similar to that of the first embodiment, a cylindrical portion 43, and a tapered portion 44 as a truncated cone-shaped "contact portion" whose diameter gradually decreases toward the needle portion 42 side. The needle portion 42 is connected to the end of the tapered portion 44, and the tapered portion 44 can contact the step portion 3a of the main valve body 3. A coil spring 7 is disposed between the guide boss portion 41' and the step portion 3a of the main valve body 3 via an annular spring receiver 7a made of lubricating resin.

[0036] With the above configuration, similarly to the first embodiment, small flow rate control is performed by a constant flow rate of refrigerant flowing through the first throttle section between the straight section 42a of the needle portion 42 and the sub-valve port 33a, and in this small flow rate control state, the tapered section 44 of the needle valve 4' abuts against the step section 3a of the main valve element 3. Then, at this time, the needle valve 4' presses the main valve element 3 toward the main valve seat 13 due to the biasing force of the coil spring 7. Therefore, even if a pressure change occurs in the fluid between the main valve chamber 1R and the main valve port 13a, the main valve element 3 does not vibrate, and controllability in the small flow rate range is improved.

[0037] FIG. 9 is an enlarged longitudinal sectional view of a main part of the motor-operated valve of the fourth embodiment in the small flow control region state. In this fourth embodiment, the tapered portion 44 of the third embodiment is eliminated. The needle valve 4″ of this fourth embodiment is composed of a thin guide boss portion 41″ (flange portion) formed integrally with the rotor shaft 51, a needle portion 42 as an “auxiliary valve body” similar to the first embodiment, and a long truncated cone-shaped connecting rod 43″, and the needle portion 42 is connected to the end of the connecting rod 43″. As in the third embodiment, a coil spring 7 is disposed between the guide boss portion 41″ and the step portion 3a of the main valve body 3 via a ring-shaped spring receiver 7a made of a lubricating resin. The lower end of the coil spring 7 constitutes an “abutment portion” that abuts against the step portion 3a.

[0038] With the above configuration, similarly to the first embodiment, small flow rate control is performed by allowing a constant flow rate of refrigerant to flow through the first throttling portion between the straight portion 42a of the needle portion 42 and the sub-valve port 33a, and in this small flow rate control state, the needle valve 4'' presses the main valve element 3 toward the main valve seat 13 due to the biasing force of the coil spring 6. Therefore, even if a change in fluid pressure occurs between the main valve chamber 1R and the main valve port 13a, the main valve element 3 does not vibrate, and controllability in the small flow rate range is improved.

[0039] 10 is an enlarged longitudinal sectional view of the main part of the motor-operated valve of the fifth embodiment in the small flow control region state. The difference between the fifth embodiment and the first embodiment is that a groove 8 is formed in the step portion 3a of the main valve body 3 facing the tapered portion 41a of the needle valve 4. In the fifth embodiment, the small flow control is performed in the first throttle portion between the straight portion 42a of the needle portion 42 and the sub-valve port 33a, and the needle valve 4 presses the main valve body 3 toward the main valve seat 13 during the small flow control, so that the main valve body 3 does not vibrate and the controllability in the small flow region is improved, as in the first embodiment. The groove 8 connects the needle guide hole 32a of the main valve body 3 and the guide hole 2A of the guide member 2 to the sub-valve chamber 3R, and equalizes the back pressure against the needle valve 4 with the sub-valve chamber 3R even when the tapered portion 41a is in contact with the step portion 3a of the main valve body 3.

[0040] 11 is an enlarged vertical cross-sectional view of a main part of the motor-operated valve of the sixth embodiment in a small flow rate control region state. The difference between the sixth embodiment and the first embodiment is that the groove 9 is formed in the tapered portion 41a of the needle valve 4. In the sixth embodiment, the small flow rate control is performed in the first throttle section between the straight section 42a of the needle section 42 and the sub-valve port 33a, and the needle valve 4 presses the main valve body 3 toward the main valve seat 13 during the small flow rate control, so that the main valve body 3 does not vibrate and the controllability in the small flow rate range is improved, as in the first embodiment. The groove 9 is formed from the outer circumferential side of the guide boss section 41 to the base of the straight section 42a of the needle section 42. As in each of the above embodiments, the small flow rate control is performed by a constant flow rate of refrigerant flowing through the first throttle section between the straight section 42a of the needle section 42 and the sub-valve port 33a. The groove 9 connects the needle guide hole 32a of the main valve body 3 and the guide hole 2A of the guide member 2 to the sub-valve chamber 3R, and equalizes the back pressure on the needle valve 4 with the sub-valve chamber 3R even when the tapered section 41a is in contact with the step section 3a of the main valve body 3.

[0041] Next, the refrigeration cycle system of the present invention will be described with reference to Fig. 12. The refrigeration cycle system is used, for example, in an air conditioner such as a home air conditioner. The motor-operated valve 100 of 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 to constitute a heating and cooling device.

[0042] 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 opened, and the first indoor heat exchanger 91 and the second indoor heat exchanger 92 are combined 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.

[0043] 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 the motor-operated valve 100 used in an air conditioner such as a home air conditioner, but the motor-operated valve of the present invention is not limited to home air conditioners, but may be used in commercial air conditioners, and is not limited to air conditioners, but may also be used in various types of refrigerators, etc.

[0044] In the above embodiment, an example was described in which a tapered portion was formed as the contact portion on the needle valve side and a step portion was formed as the contact portion on the main valve body side, but a cylindrical step portion may be formed on the needle valve side and a cone-shaped tapered portion may be formed on the main valve body side so as to face the cylindrical step portion. In the above embodiment, the second throttle portion formed on the main valve body, the main valve seat, the step portion or the needle valve was described as having a groove configuration, but the second throttle portion is not limited to a groove and may be a second throttle portion formed by a hole or the like.

[0045] The above describes in detail the embodiments of the present invention with reference to the drawings, and also describes in detail other embodiments. However, the specific configuration is not limited to these embodiments, and the present invention also includes design changes and the like that do not deviate from the gist of the present invention. [Explanation of symbols]

[0046] 1 Valve housing 1R main valve chamber 11 First joint pipe 12 Second joint pipe 13 Main valve seat 13a Main valve port 14 cases 2 Guide member 2A Guide hole 21 Press-fit section 22 Guide section 23 Guide section 24 Holder part 24a Female thread 25 Flange 3 Main valve body 3R Sub-valve chamber 3a Stepped part (contact part) 31 Main valve section 32 Holding part 32a Needle guide hole 32b Conduction hole 33 Sub-valve seat 33a Sub-valve port 34 Retainer 35 Main valve spring 4 Needle valve (auxiliary valve body) 41 Guide boss 41a Tapered portion (contact portion) 42 Needle section 43 Washer 5 Drive unit 5A stepper motor 51 Rotor shaft 51a Male thread 52 Magnet rotor 53 Stator coil 54 Spring support 55 Coil spring 5B Screw feed mechanism 5C Stopper mechanism L axis 6 grooves 6′ groove 4′ Needle valve (auxiliary valve body) 41' Guide boss 42 Needle section 43 Cylinder section 44 Tapered section (contact section) 7a Spring holder 7 Coil spring 4" needle valve (sub valve) 41" Guide boss 42 Needle section 43″ connecting rod 8 grooves 9 grooves 91 1st 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

1. A two-stage motor-operated valve comprising a main valve body disposed adjacent to or separated from a main valve seat formed on a periphery of a main valve port provided in a main valve chamber of a valve housing, and a sub-valve body disposed adjacent to or separated from a sub-valve seat formed on a periphery of a sub-valve port provided in a sub-valve chamber inside the main valve body, The sub-valve body and the main valve body each have a contact portion that contacts with each other directly or indirectly via a coil spring, the sub-valve element has a straight portion formed of a cylinder having a center line coincident with the axis of the valve housing, The outer diameter of the straight portion is smaller than the inner diameter of the auxiliary valve port, A through hole is formed to communicate between the main valve chamber and the sub-valve chamber, an auxiliary valve body pressing the main valve body in the center line direction with the abutment portion, wherein at least a portion of one end side of the straight portion is located within the auxiliary valve port, and an edge portion of an inner opening edge portion of the through hole closest to the auxiliary valve port is located between the one end portion of the straight portion and the other end portion of the straight portion in the center line direction.

2. A two-stage motor-operated valve comprising a main valve body disposed adjacent to or separated from a main valve seat formed on a periphery of a main valve port provided in a main valve chamber of a valve housing, and a sub-valve body disposed adjacent to or separated from a sub-valve seat formed on a periphery of a sub-valve port provided in a sub-valve chamber inside the main valve body, The sub-valve body and the main valve body each have a contact portion that contacts with each other directly or indirectly via a coil spring, the sub-valve element has a straight portion formed of a cylinder having a center line coincident with the axis of the valve housing, The outer diameter of the straight portion is smaller than the inner diameter of the auxiliary valve port, a small flow rate control region state in which a flow rate is controlled by a first throttle portion formed between the straight portion and the sub-valve port in a state in which the main valve element closes the main valve port and the sub-valve element presses the main valve element in the center line direction at the abutment portion, A through hole is formed to communicate between the main valve chamber and the sub-valve chamber, an electrically-operated valve characterized in that, in the small flow rate control region state, at least a portion of one end side of the straight portion is located within the auxiliary valve port, and an edge portion of an inner opening edge portion of the through hole closest to the auxiliary valve port is located between one end portion of the straight portion and the other end portion of the straight portion in the center line direction.

3. An electric valve as described in claim 1 or 2, characterized in that the straight portion and the through hole are positioned between the abutment portion and the auxiliary valve port in the center line direction, thereby connecting the through hole and the auxiliary valve port.

4. The motor-operated valve according to any one of claims 1 to 3, characterized in that, in a state in which a first throttling portion consisting of a radial gap between the straight portion and the sub-valve port is formed, the sub-valve body is configured to press the main valve body against the main valve seat.

5. The sub-valve body includes the contact portion and a needle portion, The motor-operated valve according to any one of claims 1 to 4, characterized in that the needle portion comprises the straight portion and a needle that reduces in diameter toward the main valve port side and is connected to the main valve port side of the straight portion.

6. 6. The motor-operated valve according to claim 1, wherein at least one of the contact portions between the sub-valve body and the main valve body is a step portion.

7. 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, wherein the motor-operated valve according to any one of claims 1 to 6 is used as the dehumidification valve.

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