Electric valves and refrigeration circulation system

Abstract

This invention provides an electric valve and a refrigeration cycle system. The electric valve has a two-stage flow control domain. The main valve port of the main valve seat is fully closed by the main valve core, and the refrigerant flow is controlled in the small flow control domain by the throttling section formed between the auxiliary valve port and the needle valve formed by the main valve core. For this electric valve, vibration of the main valve core in the small flow control domain is prevented, and the controllability in the small flow domain is improved. The main valve port (13a) is fully closed by the main valve core (3), and fluid flows through the throttling section (gap) between the needle part (42) of the needle valve (4) and the auxiliary valve port (33a), thus forming a small flow control domain. In the small flow control domain, the conical part (41a) (abutment part) of the needle valve (4) (auxiliary valve core) abuts against the stepped part (3a) (abutment part) of the main valve core (3). By abutting the tapered part (41a) and the stepped part (3a), the needle valve (4) pushes the main valve core (3) to the side of the main valve seat (13).

Description

Technical Field

[0001] This invention relates to electric valves and refrigeration circulation systems used in refrigeration circulation systems, etc. Background Technology

[0002] Conventionally, electric valves installed in the refrigeration cycle of air conditioners are known to control flow in both small and large flow control domains. Such electric valves are used in indoor units (e.g., as dehumidifiers) and are disclosed, for example, in Japanese Patent Application Publication No. 2019-132347 (Patent Document 1).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-132347 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] In the case of this type of electric valve, in a low-flow control region, such as during dehumidification operation, the main valve is configured to keep the main valve port of the main valve seat fully closed by the main valve core, allowing the refrigerant to pass through a throttling section formed between the auxiliary valve port of the main valve core and the needle valve (auxiliary valve core). However, due to pulsations in the refrigerant flow on the primary or secondary side, pressure changes and piping vibrations occur, leading to a problem where the main valve core vibrates, reducing the controllability in the low-flow region.

[0008] The objective of this invention is to prevent vibration of the main valve core in the low-flow-rate control region and improve controllability in the low-flow-rate control region in an electric valve with a two-stage flow control region. The electric valve forms the main valve core in a seated state, and controls the flow of refrigerant in the low-flow-rate control region through a throttling section between the main valve core and the main valve seat, and a throttling section formed between the auxiliary valve port and the needle valve formed on the main valve core.

[0009] Solution for solving the problem

[0010] The electric valve of the present invention is a two-stage electric valve, comprising a main valve core that is close to or far from a main valve seat formed in the main valve chamber of the valve body, and a secondary valve core that is close to or far from a secondary valve seat formed in the secondary valve chamber inside the main valve core, and a secondary valve core that is close to or far from a secondary valve seat formed in the secondary valve chamber inside the main valve core. The electric valve is characterized in that, when the main valve core is seated in the main valve seat, the secondary valve core does not abut against the secondary valve seat, but rather abuts against the main valve core, thereby pushing the main valve core against the main valve seat.

[0011] Furthermore, preferably, the electric valve is characterized in that a through hole is formed on the lower side of the contact portion on the side of the auxiliary valve chamber, connecting the main valve chamber and the auxiliary valve chamber.

[0012] At this point, it is preferable that the electric valve is characterized in that, regarding the abutting portion of the aforementioned auxiliary valve core and the aforementioned main valve core, one is a tapered portion with the axis of the aforementioned auxiliary valve port as the central axis, and the other is a stepped portion with the aforementioned axis as the central axis.

[0013] Furthermore, preferably, the electric valve is characterized in that the abutting portions of the sub-valve core and the main valve core are abutted by a spring provided between the flange portion of the sub-valve core and the stepped portion of the main valve core.

[0014] Furthermore, preferably, the electric valve is characterized by having a communication path that passes through the valve chamber via a hole in the axial direction provided in the flange of the guide member, through a communication hole provided in the guide member within the guide portion, and through the gap between the outer periphery of the secondary valve core and the inner periphery of the main valve core to reach the lower part of the secondary valve chamber.

[0015] Furthermore, preferably, the electric valve is characterized by having a first throttling section formed by the gap between the needle portion of the aforementioned secondary valve core and the aforementioned secondary valve port.

[0016] Furthermore, preferably, the electric valve is characterized in that a second throttling portion is formed in the main valve seat or the main valve core, and / or in the secondary valve seat or the secondary valve core.

[0017] Furthermore, preferably, the electric valve is characterized in that the second throttling section is formed by a groove or a hole.

[0018] The refrigeration cycle system of the present invention includes a compressor, an indoor heat exchanger, an outdoor heat exchanger, an electronic expansion valve disposed between the indoor heat exchanger and the outdoor heat exchanger, and a dehumidification valve disposed in the indoor heat exchanger. The refrigeration cycle system is characterized in that the electric valve is used as the dehumidification valve.

[0019] The effects of the invention

[0020] According to the electric valve and refrigeration circulation system of the present invention, in the state of low flow control based on the throttling section (gap) between the secondary valve core and the secondary valve port or based on the throttling section between the main valve core and the main valve seat, or between the secondary valve core and the secondary valve seat, the abutting part of the secondary valve core and the main valve core (including a spring spaced between the secondary valve core and the main valve core) abuts, and the secondary valve core pushes the main valve core to the main valve seat. Therefore, even if there is a pressure change of the fluid at the main valve port or piping vibration, the main valve core will not vibrate, and the controllability in the low flow range is improved. Attached Figure Description

[0021] Figure 1 This is a longitudinal sectional view of the low-flow control domain state of the electric valve according to the first embodiment of the present invention.

[0022] Figure 2 This is a longitudinal sectional view of the electric valve in the first embodiment when the main valve core is fully open and the operation is stopped, or when it is in cooling operation.

[0023] Figure 3 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the first embodiment.

[0024] Figure 4 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the second embodiment.

[0025] Figure 5 These are figures illustrating Embodiment 1 and Embodiment 2 of the second throttling section of the second embodiment.

[0026] Figure 6 This is an enlarged view of the needle and auxiliary valve port of the electric valve in the low flow control domain state of the first and second embodiments.

[0027] Figure 7 This is a diagram showing variations of the first and second embodiments.

[0028] Figure 8 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the third embodiment.

[0029] Figure 9 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the fourth embodiment.

[0030] Figure 10 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the fifth embodiment.

[0031] Figure 11 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the sixth embodiment.

[0032] Figure 12 This is a diagram illustrating a refrigeration cycle system according to an embodiment of the present invention.

[0033] In the picture:

[0034] 1—Valve housing, 1R—Main valve chamber, 11—First connector pipe, 12—Second connector pipe, 13—Main valve seat, 13a—Main valve port, 14—Housing, 2—Guide component, 2A—Guide hole, 21—Press-in part, 22—Guide part, 23—Guide part, 24—Retaining part, 24a—Internal thread part, 25—Flange part, 3—Main valve core, 3R—Secondary valve chamber, 3a—Step part (abutment part), 31—Main valve part, 32—Retaining part, 32a—Needle guide hole, 32b—Through hole, 33—Secondary valve seat, 33a—Secondary valve port, 34—Stop, 35—Main valve spring, 4—Needle valve (secondary valve core), 41—Guide boss part, 41a—Conical part (abutment part), 42—Needle part, 43—Washer, 5—Drive part, 5A—Step 51—Rotor shaft, 51a—External threaded part, 52—Magnetic rotor, 53—Stator coil, 54—Spring seat, 55—Disc spring, 5B—Threaded feed mechanism, 5C—Limiting mechanism, L—Axis, 6—Slot, 6′—Slot, 4′—Needle valve (secondary valve core), 41′—Guide boss part, 42—Needle part, 43—Cylindrical part, 44—Conical part (abutment part), 7a—Spring seat, 7—Disc spring, 4″—Needle valve (secondary valve core), 41″—Guide boss part, 42—Needle part, 43″—Connecting rod, 8—Slot, 9—Slot, 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—Electric valve. Detailed Implementation

[0035] Next, with reference to the accompanying drawings, embodiments of the electric valve and refrigeration circulation system of the present invention will be described. Figure 1 This is a longitudinal sectional view of the low-flow control domain state of the electric valve according to the first embodiment. Figure 2 This is a longitudinal sectional view of the electric valve of the first embodiment in its fully open state and when it is stopped or in cooling operation. Figure 3 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the first embodiment. Furthermore, the concept of "upper and lower" in the following description corresponds to... Figure 1 and Figure 2 The electric valve 100 is shown above and below in the drawing. It includes a valve housing 1, a guide component 2, a main valve core 3, a needle valve 4 serving as a "secondary valve core", and a drive unit 5.

[0036] The valve body 1 is formed into a generally cylindrical shape, for example, from brass or stainless steel, and has a main valve chamber 1R inside. A first connector pipe 11, which communicates with the main valve chamber 1R, is connected to one side of the outer periphery of the valve body 1, and a second connector pipe 12 is connected to a cylindrical portion extending downward from the lower end. Furthermore, a cylindrical main valve seat 13 is formed on the main valve chamber 1R side of the second connector pipe 12 of the valve body 1. The inner side of the main valve seat 13 is a main valve port 13a, through which the second connector pipe 12 communicates with the main valve chamber 1R. The main valve port 13a is a cylindrical through-hole centered on the axis L. The first connector pipe 11 and the second connector pipe 12 are fixed to the valve body 1 by brazing or the like.

[0037] A guide member 2 is installed at the opening at the upper end of the valve housing 1. The guide member 2 has: a press-in portion 21 pressed into the inner circumferential surface of the valve housing 1; generally cylindrical guide portions 22 and 23, which are smaller in diameter than the press-in portion 21 and located above and below the press-in portion 21; a retaining portion 24 extending to the upper part of the guide portion 22; and an annular flange portion 25 provided on the outer periphery of the press-in portion 21. The press-in portion 21, guide portions 22 and 23, and retaining portion 24 are integrally formed as a resin product. In addition, the flange portion 25 is a metal plate such as brass or stainless steel, and the flange portion 25 is integrally formed with the resin press-in portion 21 by insert molding. Furthermore, the flange portion 25 is provided with a hole (not shown) that communicates the main valve chamber 1R and the housing 14 described later in the direction of the valve shaft axis L.

[0038] The guide member 2 is assembled to the valve housing 1 via the press-in portion 21 and fixed to the upper end of the valve housing 1 by welding via the flange portion 25. Furthermore, in the guide member 2, a cylindrical guide hole 2A coaxial with the axis L is formed inside the press-in portion 21 and the upper and lower guide portions 22 and 23, and an internal thread portion 24a coaxial with the guide hole 2A and its threaded hole are formed at the center of the retaining portion 24. Moreover, the main valve core 3 is disposed inside the lower guide portion 23 and within the guide hole 2A.

[0039] The main valve core 3 includes: a main valve portion 31 that sits and leaves the main valve seat 13; a retaining portion 32 having a cylindrical needle guide hole 32a; a secondary valve seat 33 forming the bottom of the needle guide hole 32a; and a stop 34 provided at the end of the retaining portion 32. Furthermore, a secondary valve chamber 3R, connected to the needle guide hole 32a, is formed below the needle guide hole 32a, and a stepped portion 3a serving as an "abutment portion" is formed at the boundary between the secondary valve chamber 3R and the needle guide hole 32a. A washer 43, which is mounted on the rotor shaft 51 (described later), and a guide boss portion 41 of the needle valve 4, which is integrally formed with the rotor shaft 51, are inserted into the needle guide hole 32a of the retaining portion 32. In addition, the annular stop 34 is fixed to the upper end of the retaining portion 32 by fitting or welding.

[0040] Furthermore, a main valve spring 35 is provided between the upper end of the stopper 34 and the guide hole 2A. Through this main valve spring 35, the main valve core 3 is forced towards the main valve seat 13 (closing direction). A cylindrical secondary valve port 33a centered on the axis L is formed at the center of the secondary valve seat 33. In addition, a through hole 32b is formed on the side of the holding part 32, which is lower than the stepped part 3a, to conduct between the secondary valve chamber 3R and the main valve chamber 1R. When the needle valve 4, which is the secondary valve core, sets the secondary valve port 33a to the open state, the main valve chamber 1R, the secondary valve chamber 3R, the secondary valve port 33a, and the main valve port 13a are connected. Furthermore, the interior of the main valve chamber 1R and the housing 14 are connected by a hole (not shown) provided on the flange 25 and communicating in the direction of the valve shaft axis L. The interior of the housing 14 and the interior of the guide member 2 are connected by a communicating hole provided on the upper part of the guide member 2. The upper part of the main valve core 3 and the space directly above the step portion 3a of the main valve core 3 are connected by the gap between the outer periphery of the washer 43 and 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 core 3, thereby connecting the main valve chamber 1R and the auxiliary valve chamber 3R.

[0041] The needle valve 4, serving as a "secondary valve core," is integrally formed with the rotor shaft 51 at its lower end. The needle valve 4 consists of a guide boss 41 and a needle portion 42. The guide boss 41 has a tapered portion 41a, a truncated cone shape whose diameter gradually decreases towards the needle portion 42, which serves as an "abutment portion." This tapered portion 41a abuts against the stepped portion 3a (abutment portion) of the main valve core 3. The needle portion 42 is connected to the end of the tapered portion 41a. Furthermore, an annular washer 43 made of lubricating resin is disposed at 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.

[0042] A housing 14 is airtightly fixed to the upper end of the valve housing 1 by welding or the like, and a drive unit 5 is formed inside and outside the housing 14. The drive unit 5 includes: a stepper motor 5A; a threaded feed mechanism 5B that moves the needle valve 4 forward and backward by rotating the stepper motor 5A; and a limiting mechanism 5C that restricts the rotation of the stepper motor 5A.

[0043] The stepper motor 5A includes: a rotor shaft 51; a magnetic rotor 52 rotatably disposed inside a housing 14; a stator coil 53 disposed opposite to the magnetic rotor 52 on the outer periphery of the housing 14; and other components not shown, such as a magnetic yoke and external fittings. The rotor shaft 51 is mounted to the center of the magnetic rotor 52 via a bushing, and an external thread 51a is formed on the outer periphery of the rotor shaft 51 on the guide member 2 side. This external thread 51a is threaded into the internal thread 24a of the guide member 2, thereby supporting the rotor shaft 51 on the axis L by the guide member 2. Furthermore, the internal thread 24a of the guide member 2 and the external thread 51a of the rotor shaft 51 constitute a threaded feed mechanism 5B. In addition, a disc spring 55 is provided in the inner top portion of the housing 14 and in the cylindrical portion 14a that holds the rotation limiting mechanism 5C, via a spring seat 54 that abuts against the upper end of the rotor shaft 51. The disc spring 55 exerts a downward force on the rotor shaft 51, thereby preventing backlash in the threaded feed mechanism 5B.

[0044] According to the above structure, when the stepper motor 5A is driven, the magnetic rotor 52 and rotor shaft 51 rotate. Through the threaded feed mechanism 5B between the external thread 51a of the rotor shaft 51 and the internal thread 24a of the guide member 2, the rotor shaft 51 and the magnetic rotor 52 move together along the axis L. Then, the needle valve 4 moves forward and backward along the axis L, approaching or moving away from the auxiliary valve port 33a. In addition, when the needle valve 4 rises, the washer 43 engages with the stop 34 of the main valve core 3, and the main valve core 3 moves together with the needle valve 4 and disengages from the main valve seat 13. Furthermore, a protrusion 52a is formed on the magnetic rotor 52. As the magnetic rotor 52 rotates, the protrusion 52a causes the rotation limiting mechanism 5C to operate, restricting the lowermost and uppermost positions of the rotor shaft 51 (and the magnetic rotor 52).

[0045] Figure 1 In the low-flow control range, with the main valve core 3 seated in the main valve seat 13, the main valve port 13a is closed, and the opening of the auxiliary valve port 33a is controlled by the needle valve 4 to achieve low-flow control. Additionally, in situations such as when the compressor in a refrigeration cycle system stops and the fluid (refrigerant) stops, when the needle valve 4 and the main valve core 3 are in the upward position, such as... Figure 2 As shown, the main valve port 13a is fully open. Thus, during cooling operation, a large flow of fluid (refrigerant) flows from the first connector pipe 11 to the second connector pipe 12, or during heating operation, a large flow of fluid (refrigerant) flows from the second connector pipe 12 to the first connector pipe 11.

[0046] like Figure 3As shown, the needle portion 42 includes: a straight portion 42a formed by a cylinder centered on axis L; and a needle 42b with a reduced diameter towards the front end. Furthermore, the outer diameter of the straight portion 42a is smaller than the inner diameter of the secondary valve port 33a, forming a first throttling portion (gap) between the straight portion 42a and the secondary valve port 33a. Moreover, by allowing a certain flow rate of refrigerant to flow through this first throttling portion, small flow rate control is achieved. In this small flow rate control state, the guide member of the needle valve 4 abuts against the stepped portion 3a of the main valve core 3 with the tapered portion 41a of the boss portion 41. At this time, the needle valve 4 presses the main valve core 3 towards the main valve seat 13 by the force of the disc spring 55 used for backlash prevention. Therefore, even if a pressure change occurs between the main valve chamber 1R and the main valve port 13a, the main valve core 3 will not vibrate, improving controllability in the small flow rate range.

[0047] Figure 4 This is an enlarged longitudinal sectional view of the main part of the low-flow control domain state of the electric valve in the second embodiment. Figure 5 These are figures illustrating Embodiments 1 and 2 of the second throttling section of the second embodiment. Figure 6 This is an enlarged view of the needle and auxiliary valve port of the electric valve in the low flow control range state of the first and second embodiments. Figure 7 This diagram illustrates variations of the electric valve according to the first and second embodiments. In the following embodiments and variations, the overall structure of the electric valve is similar to... Figure 1 and Figure 2 same.

[0048] Figure 4 In the second embodiment of the electric valve, similarly to the first embodiment, a first throttling section is formed between the straight portion 42a of the needle portion 42 and the secondary valve port 33a. Furthermore, in the state of low flow control, the conical portion 41a of the needle valve 4 abuts against and presses against the stepped portion 3a of the main valve core 3, preventing the main valve core 3 from vibrating and improving controllability in the low flow range. In addition, in the second embodiment, a second throttling section P is formed between the main valve core 3 and the main valve seat 13.

[0049] Figure 5 In Embodiment 1 (A), a groove 6 serving as a "second throttling section P" is formed at the opening edge of the main valve port 13a of the main valve seat 13. The groove 6, through the first throttling section between the auxiliary valve port 33a and the straight portion 42a of the needle portion 42, performs small-flow control, allowing refrigerant to flow from the main valve chamber 1R to the main valve port 13a via the groove 6. Consequently, the pressure difference before and after the throttling section between the auxiliary valve port 33a and the needle portion 42 is reduced, thereby decreasing the refrigerant flow noise at the throttling section.

[0050] Figure 5In Embodiment 2 (B), a groove 6' serving as a "second throttling section P" is formed in the main valve section 31 of the main valve 3. Furthermore, similar to Embodiment 1, when the groove 6' performs small-flow control through the first throttling section of the needle section 42 and the auxiliary valve port 33a, it also facilitates the flow of refrigerant from the main valve chamber 1R to the main valve port 13a. Consequently, the pressure difference before and after the throttling section of the needle section 42 and the auxiliary valve port 33a is reduced, thereby decreasing the refrigerant flow noise at the throttling section.

[0051] In addition, such as Figure 6 As shown, the needle portion 42 includes: a straight portion 42a formed by a thin cylinder with the axis L as its center line; and a needle 42b with a reduced diameter towards the front end. Furthermore, the outer diameter of the straight portion 42a is smaller than the inner diameter of the secondary valve port 33a, and a first throttling portion (gap) is formed between the straight portion 42a and the secondary valve port 33a. A certain flow rate of refrigerant flows through this first throttling portion for low-flow control. Additionally, during this low-flow control, the pressure of the refrigerant flowing into the throttling portion between the straight portion 42a and the secondary valve port 33a is dispersed around the axis L by the groove 6 (second throttling portion) formed on the secondary valve chamber 3R side of the secondary valve port 33a. This reduces the pressure difference before and after the first throttling portion formed by the secondary valve seat 33 and the needle portion 42, thereby reducing the refrigerant noise at the first throttling portion.

[0052] Figure 7 In this modified example, a groove 4a serving as a "second throttling section" is formed in the needle portion 42. The groove 4a extends from the root portion 42c of the guide boss portion 44 of the needle portion 42 to approximately the middle of the straight portion 42a. Furthermore, multiple grooves 4a are formed (six in this example), and these grooves 4a are formed at equally spaced (every 60°) positions relative to the axis L, exhibiting rotational symmetry. Further, the area of ​​the horizontal cross-section of the groove 4a decreases towards the secondary valve port 33a in the direction of the axis L. In this modified example, the groove 4a is formed only to approximately the middle of the straight portion 42a; therefore, the opening area of ​​the throttling section of the straight portion 42a and the secondary valve port 33a is constant, similar to the previous embodiment, enabling the flow rate to be kept constant during low-flow control.

[0053] Furthermore, in this modified example, when the flow rate is controlled at low flow rate, the pressure of the refrigerant flowing into the throttling section 42a and the secondary valve port 33a is also dispersed around the axis L by the groove 4a formed on the needle section 42. The pressure difference before and after the throttling section formed by the secondary valve seat 33 and the needle section 42 is reduced, which can reduce the refrigerant flow noise at the throttling section.

[0054] Figure 8This is an enlarged longitudinal sectional view of the main part of the electric valve in the low-flow control range state according to the third embodiment. The difference between this third embodiment and the first embodiment lies in the construction of the needle valve 4′, which serves as the "secondary valve core". The needle valve 4′ of this third embodiment includes: a thin guide boss portion 41′ integrally formed with the rotor shaft 51; a needle portion 42, the same as in the first embodiment; a cylindrical portion 43; and a tapered portion 44, which is a frustum-shaped "abutment portion" with a diameter that gradually decreases toward the needle portion 42. Moreover, the ends of the needle portion 42 and the tapered portion 44 are connected, and the tapered portion 44 can abut against the step 3a of the main valve core 3. In addition, a disc spring 7 is provided between the guide boss portion 41′ and the step portion 3a of the main valve core 3 via a ring-shaped spring seat 7a made of lubricating resin.

[0055] Based on the above structure, similarly to the first embodiment, a certain flow rate of refrigerant flows through the first throttling section between the straight portion 42a of the needle valve 42 and the auxiliary valve port 33a, achieving low-flow control. Under this low-flow control state, the conical portion 44 of the needle valve 4' abuts against the stepped portion 3a of the main valve core 3. Furthermore, at this time, the needle valve 4' presses the main valve core 3 towards the main valve seat 13 by the force of the coil spring 7. Therefore, even if a pressure change occurs between the main valve chamber 1R and the main valve port 13a, the main valve core 3 will not vibrate, improving controllability in the low-flow range.

[0056] Figure 9 This is an enlarged longitudinal sectional view of the main part of the electric valve in the low flow control range state according to the fourth embodiment. This fourth embodiment eliminates the tapered portion 44 of the third embodiment. The needle valve 4″ of this fourth embodiment includes: a thin guide boss portion 41″ (flange portion) integrally formed with the rotor shaft 51; a needle portion 42 serving as a "secondary valve core" as in the same embodiment; and a long, frustoconical connecting rod 43″, with the needle portion 42 connected to the end of the connecting rod 43″. Furthermore, similar to the third embodiment, a disc spring 7 is provided between the guide boss portion 41″ and the stepped portion 3a of the main valve core 3 via an annular spring seat 7a made of lubricating resin. Moreover, the lower end of the disc spring 7 forms an "abutment portion" that abuts against the stepped portion 3a.

[0057] Based on the above structure, similarly to the first embodiment, a certain amount of refrigerant flows through the first throttling section between the straight portion 42a of the needle 42 and the auxiliary valve port 33a, achieving low-flow control. Under this low-flow control state, the needle valve 4″ presses the main valve core 3 towards the main valve seat 13 by the force of the disc spring 6. Thus, even if a pressure change occurs between the main valve chamber 1R and the main valve port 13a, the main valve core 3 will not vibrate, improving the controllability in the low-flow range.

[0058] Figure 10This is an enlarged longitudinal sectional view of the main part of the electric valve in the low-flow control range state according to the fifth embodiment. The difference between this fifth embodiment and the first embodiment is that a groove 8 is formed in the stepped portion 3a of the main valve core 3, which is opposite to the tapered portion 41a of the needle valve 4. Even in this fifth embodiment, similar to the first embodiment, during low-flow control at the first throttling portion between the straight portion 42a of the needle portion 42 and the auxiliary valve port 33a, the needle valve 4 presses the main valve core 3 against the main valve seat 13, thus preventing vibration of the main valve core 3 and improving controllability in the low-flow range. The groove 8 connects the needle guide hole 32a of the main valve core 3 and the guide hole 2A of the guide member 2 to the auxiliary valve chamber 3R, ensuring that even when the tapered portion 41a abuts against the stepped portion 3a of the main valve core 3, the back pressure on the needle valve 4 is equal to that on the auxiliary valve chamber 3R.

[0059] Figure 11 This is an enlarged longitudinal sectional view of the main part of the low-flow control range state of the electric valve according to the sixth embodiment. The difference between this sixth embodiment and the first embodiment is that a groove 9 is formed in the tapered portion 41a of the needle valve 4. Even in this sixth embodiment, similar to the first embodiment, low-flow control is performed through the first throttling section between the straight portion 42a of the needle portion 42 and the auxiliary valve port 33a. During this low-flow control, the needle valve 4 presses the main valve core 3 against the main valve seat 13, thereby preventing vibration of the main valve core 3 and improving the controllability in the low-flow range. The groove 9 is formed from the outer periphery of the guide boss portion 41 to the root of the straight portion 42a of the needle portion 42. Similar to the embodiments described above, low-flow control is performed by allowing a certain flow rate of refrigerant to flow through the first throttling section between the straight portion 42a of the needle portion 42 and the auxiliary valve port 33a. The groove 9 connects the needle guide hole 32a of the main valve core 3 and the guide hole 2A of the guide component 2 with the auxiliary valve chamber 3R, so that even when the tapered part 41a abuts against the stepped part 3a of the main valve core 3, the back pressure of the needle valve 4 is the same as that of the auxiliary valve chamber 3R.

[0060] Next, based on Figure 12 The refrigeration cycle system of the present invention will be described. The refrigeration cycle system is used, for example, in air conditioners such as household air conditioners. In the above embodiment, the electric valve 100 is located between the first indoor heat exchanger 91 (which operates as a cooler during dehumidification) and the second indoor heat exchanger 92 (which operates as a heater during dehumidification) of the air conditioner, and together with the compressor 95, the four-way valve 96, the outdoor heat exchanger 94, and the electronic expansion valve 93, constitutes a heat pump refrigeration cycle. The first indoor heat exchanger 91, the second indoor heat exchanger 92, and the electric valve 100 are located indoors, while the compressor 95, the four-way valve 96, the outdoor heat exchanger 94, and the electronic expansion valve 93 are located outdoors, thus constituting a cooling and heating device.

[0061] In the implementation of the dehumidification valve, the electric valve 100, during cooling or heating (excluding dehumidification), has its main valve core fully open, and the first indoor heat exchanger 91 and the second indoor heat exchanger 92 form a single indoor heat exchanger. Furthermore, this integrated indoor heat exchanger and outdoor heat exchanger 94 can selectively function as either an "evaporator" or a "condenser." That is, the electric valve 93, which functions as an electronic expansion valve, is located between the evaporator and the condenser.

[0062] Furthermore, the present invention is not limited to the embodiments described above, and includes other structures that can achieve the purpose of the present invention, such as the variations shown below. For example, the electric valve 100 for air conditioners such as household air conditioners is exemplified in the above embodiments, but the electric valve of the present invention is not limited to household air conditioners, but can also be used in industrial air conditioners, and is not limited to air conditioners, but can also be applied to various refrigeration units, etc.

[0063] Furthermore, in the above embodiment, an example was described where a tapered portion as an abutment is formed on the needle valve side, and a stepped portion as an abutment is formed on the main valve core side. However, it is also possible to form a cylindrical stepped portion on the needle valve side and a mortar-shaped tapered portion opposite to the cylindrical stepped portion on the main valve core side. Additionally, in the above embodiment, the second throttling portion formed on the main valve core, main valve seat, stepped portion, or needle valve is described as a groove structure. However, the second throttling portion is not limited to a groove; it can also be a second throttling portion implemented through a hole or the like.

[0064] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. Other embodiments have also been described in detail, but the specific structure is not limited to these embodiments. Any design changes that do not depart from the spirit of the present invention are considered part of the present invention.

Claims

1. An electric valve, which is a two-stage electric valve, comprising a main valve core that is close to or far from a main valve seat formed in a main valve chamber of a valve housing, and a secondary valve core that is close to or far from a secondary valve seat formed in a secondary valve chamber inside the main valve core, the secondary valve core being close to or far from a secondary valve seat formed in a secondary valve chamber inside the main valve core; a drive unit for driving the main valve core and the secondary valve core; and a rotor shaft for transmitting the drive of the drive unit. The electric valve described above is characterized in that, The aforementioned rotor shaft integrally incorporates the aforementioned secondary valve core. The aforementioned secondary valve core includes a washer and a first abutment portion. The main valve core has a second abutting portion that abuts against the first abutting portion on the secondary valve core side and a stop that engages with the washer on the secondary valve core. The rotor shaft is configured to allow the secondary valve core to separate from the secondary valve seat, and to engage the gasket with the stop, thereby lifting the main valve core from the main valve seat. The aforementioned auxiliary valve core and the aforementioned main valve core are abutted together in a manner that allows their abutting portions to separate or contact each other. The configuration is such that, with the main valve core seated in the main valve seat, the main valve port is closed. The main valve core is provided with a through hole connecting the main valve chamber and the auxiliary valve chamber. The opening degree of the aforementioned secondary valve port is controlled by the needle valve provided in the aforementioned secondary valve core. A first throttling section is formed between the needle portion of the aforementioned secondary valve core and the aforementioned secondary valve port. Small flow rate control is achieved by allowing a certain flow rate of refrigerant to flow in the first throttling section. Under this low flow control state, The needle portion never comes into contact with the secondary valve seat. Instead, when the first contact portion on the secondary valve core side comes into contact with the second contact portion on the main valve core side, the through hole is located between the first contact portion and the first throttling portion on the secondary valve core side relative to the axial direction of the main valve core. Furthermore, the secondary valve core can push the main valve core to the main valve seat.

2. The electric valve according to claim 1, characterized in that, A through hole connecting the main valve chamber and the secondary valve chamber is formed on the side of the secondary valve chamber that is lower than the abutting part.

3. The electric valve according to claim 1, characterized in that, Regarding the aforementioned contact portions of the auxiliary valve core and the main valve core, one is a tapered portion with the axis of the auxiliary valve port as the center axis, and the other is a stepped portion with the axis as the center axis.

4. The electric valve according to any one of claims 1 to 3, characterized in that, The following connecting path is formed: the main valve chamber passes through the axial hole provided in the flange of the guide member, passes through the connecting hole provided in the guide part of the guide member, passes through the flow path connecting the guide part and the interior of the main valve core, passes through the gap between the outer periphery of the secondary valve core and the inner periphery of the main valve core, and reaches the lower part of the secondary valve chamber.

5. The electric valve according to claim 1, characterized in that, A second throttling portion is formed in the main valve seat or the main valve core, and / or in the auxiliary valve seat or the auxiliary valve core.

6. The electric valve according to claim 5, characterized in that, The aforementioned second throttling section is composed of a groove or a hole.

7. A refrigeration cycle system comprising a compressor, an indoor heat exchanger, an outdoor heat exchanger, an electronic expansion valve disposed between the indoor heat exchanger and the outdoor heat exchanger, and a dehumidification valve disposed in the indoor heat exchanger. The above-mentioned refrigeration cycle system is characterized in that, The electric valve according to any one of claims 1 to 6 is used as the above-mentioned dehumidification valve.

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