Motor-operated valve

Abstract

To provide a motor valve capable of reducing the aggression of detached foreign matters against a valve part when a noise elimination member is detached and of suppressing resulting corrosion while preventing the generation of rust on the noise elimination member.SOLUTION: A motor valve 10 has a small flow amount control region where a main valve port 1B is closed with a main valve element 3 and the opening of a sub valve port 3D provided in the main valve element 3 is controlled by a needle valve 42 of a sub valve element 4 to restrict the flow amount of fluid in a gap between the needle valve 42 and the sub valve port 3D. In the main valve element 3, a communication path 3E which is opened to a main valve chamber 1A and an annular space 3F which annularly continues between the communication path 3E and a sub valve chamber 3B around an axial line L are formed. Between the communication path 3E and the sub valve port 3D, resin noise elimination members 35, 37 are provided for eliminating noise which occurs when the fluid passes therethrough.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, motor-operated valves that control flow rate between a small flow rate control range and a large flow rate range are known as motor-operated valves installed in the refrigeration cycle of air conditioners (see, for example, Patent Documents 1 and 2). Such conventional motor-operated valves include a main valve body and a sub-valve body, and perform small flow rate control by causing refrigerant (fluid) to flow from a communication passage in the sub-valve body into a sub-valve chamber within the main valve body and throttling the refrigerant through a port throttling section, which is the gap between the needle valve of the sub-valve body and the sub-valve port. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2020-106086 [Patent Document 2] Japanese Patent Application Publication No. 2019-128001 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in conventional motor-operated valves such as that described in Patent Document 1, when the refrigerant flowing into the communication passage is in an unstable state due to a mixture of gas and liquid phases, if the refrigerant flows into the port restriction section in an unstable state, the refrigerant passing noise at the port restriction section increases.

[0005] On the other hand, the motor-operated valve described in Patent Document 2 is equipped with a sound-absorbing member that breaks down bubbles in the refrigerant (fluid) flowing through the communication passage (small flow passage) in order to suppress the above-mentioned refrigerant passing noise. However, because the sound-absorbing member is mainly a porous body made from sintered metal or laminated wire or molded wire, there is a problem of corrosion due to the following factors. Causes of corrosion include erosion when the fluid passes through, impurities in the piping, being left in a humid environment or a salt-damaged environment, and metal foreign matter clogging the valve when the sound-absorbing member peels off.

[0006] The object of the present invention is to provide an electric valve in which the main valve port is fully closed by the main valve body and the flow rate of the fluid in a small flow rate control range is controlled by a gap between the sub-valve port provided on this main valve body and the sub-valve body, which can prevent the occurrence of rust in the silencing member and reduce the aggressiveness of foreign matter that peels off the silencing member to the valve part when the silencing member peels off, thereby suppressing corrosion caused by these factors. [Means for solving the problem]

[0007] a needle valve in the sub-valve chamber; a sub-valve element in the sub-valve chamber formed within the main valve element, the needle valve in the sub-valve element controlling the opening of the sub-valve port in the main valve element, and a small flow control range in which the flow rate of fluid is restricted by a gap between the needle valve and the sub-valve port; a connecting passage in the main valve element that opens toward the main valve chamber, and an annular space that is continuous around the axis between the connecting passage and the sub-valve chamber; a sound-absorbing member made of resin that allows the fluid to pass through, the sub-valve port being provided between the connecting passage and the sub-valve port; a sub-valve seat centered on the axis and formed around the sub-valve port; the annular space being formed on the outer periphery of the sub-valve seat and having a groove shape recessed below the top surface of the sub-valve seat;

[0008] According to the present invention, since the sound deadening member is made of resin, rust can be prevented, and the low hardness of the material reduces the attack of foreign matter on the valve portion when the sound deadening member peels off, thereby suppressing corrosion caused by these factors. In addition, since the sound deadening member is made of resin, there is a high degree of freedom in shape and it can be produced in large quantities by resin molding. Furthermore, since resin materials have better vibration damping properties than metals, they are advantageous in terms of resisting the effects of vibration, making it possible to maintain good operability.

[0009] In this case, it is preferable that the annular space is located radially inward and above the communication passage, is continuous in an annular shape around the axis, is open upward, and is not open downward. [Effects of the Invention]

[0010] According to the motor-operated valve of the present invention, the sound-absorbing member for suppressing the refrigerant passing noise in the motor-operated valve is made of resin, which prevents rust from occurring. In addition, the low hardness of the material reduces the aggressiveness of foreign matter that peels off the sound-absorbing member toward the valve portion when the sound-absorbing member peels off, thereby suppressing corrosion caused by these factors. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a longitudinal sectional view showing a motor-operated valve according to a first embodiment of the present invention. [Figure 2] FIG. 4 is an enlarged cross-sectional view showing a main part of the motor-operated valve in a small flow rate control range state. [Figure 3] FIG. 10 is a diagram showing the flow of fluid in a small flow rate control range state of the motor-operated valve. [Figure 4] FIG. 4 is an enlarged cross-sectional view showing a first modified example of the motor-operated valve. [Figure 5] FIG. 10 is an enlarged cross-sectional view showing a second modified example of the motor-operated valve. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing a third modified example of the motor-operated valve. [Figure 7] FIG. 10 is an enlarged cross-sectional view showing a fourth modified example of the motor-operated valve. [Figure 8] FIG. 5 is an enlarged cross-sectional view showing a main part of a motor-operated valve according to a second embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view showing a fifth modified example of the motor-operated valve. [Figure 10] FIG. 10 is an enlarged cross-sectional view showing a sixth modified example of the motor-operated valve. [Figure 11] FIG. 10 is an enlarged cross-sectional view showing a seventh modified example of the motor-operated valve. [Figure 12] FIG. 10 is an enlarged cross-sectional view showing an eighth modified example of the motor-operated valve. [Figure 13] FIG. 10 is an enlarged cross-sectional view showing a ninth modified example of the motor-operated valve. DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiments of the motor-operated valve of the present invention will be described with reference to the drawings. Fig. 1 is a longitudinal cross-sectional view showing a motor-operated valve of a first embodiment of the present invention, Fig. 2 is an enlarged cross-sectional view showing the main parts of the motor-operated valve in the small flow rate control range state (sub-valve lower end position), and Fig. 3 is a diagram showing the flow of refrigerant (fluid) in the motor-operated valve in the small flow rate control range state. In the following description, the concepts of "up" and "down" correspond to the up and down in Fig. 1, and these up and down directions are sometimes referred to as the direction of axis L, and the direction perpendicular to axis L is sometimes referred to as the radial direction. In addition, in the second and subsequent embodiments described below, components and parts that are the same as or similar to those in the first embodiment will be given the same reference numerals, and descriptions thereof may be omitted or simplified.

[0013] The motor-operated valve 10 of this embodiment includes a valve housing 1 which is a valve body, a guide member 2, a main valve element 3, a sub-valve element 4, and a drive unit 5.

[0014] The valve housing 1 is formed in a generally cylindrical shape from brass, stainless steel, or the like, and has a main valve chamber 1A therein. A first coupling pipe 11, which is connected to the main valve chamber 1A, is connected to one side of the outer periphery of the valve housing 1, and a second coupling pipe 12 is connected to a cylindrical portion extending downward from the lower end. A main valve seat 13 is formed on the main valve chamber 1A side of the second coupling pipe 12 of the valve housing 1, and the inside of this main valve seat 13 forms a main valve port 1B. The main valve port 1B is a cylindrical hole centered on the axis L, and the second coupling pipe 12 is connected to the main valve chamber 1A via the main valve port 1B. In this embodiment, the main valve seat 1B is formed integrally with the valve housing 1. However, a valve seat member having a main valve port may be provided separately from the valve housing and assembled to the valve housing.

[0015] A guide member 2 is attached to the opening at the upper end of the valve housing 1. The guide member 2 has a fitting portion 21 that fits into the inner circumferential surface of the valve housing 1, a substantially cylindrical guide portion 22 that is located inside the fitting portion 21 and has its center on the axis L, a holder portion 23 that extends from the upper part of the guide portion 22, a stopper portion 24 that is provided above the holder portion 23, and a ring-shaped fixing bracket 25 made of a metal plate that protrudes from the outer periphery of the fitting portion 21. The fitting portion 21, upper guide portion 22, holder portion 23, and stopper portion 24 are configured as a single piece made of resin, and the fixing bracket 25 is formed integrally with the resin fitting portion 21 by insert molding. The fitting portion 21 of the guide member 2 may be press-fitted into the valve housing 1.

[0016] The guide member 2 is assembled to the valve housing 1 by a fitting portion 21 and is fixed to the upper end of the valve housing 1 by welding via a fixing bracket 25. A cylindrical guide hole 2A is formed in the guide member 2 on the inside of the fitting portion 21 and the guide portion 22, and is coaxial with the axis L. A through hole 2B is formed in the center of the holder portion 23, and is coaxial with the guide hole 2A and guides a rotor shaft 51 (described later) in the forward and backward direction. A female thread portion 2C is formed in the center of the stopper portion 24, and is coaxial with the guide hole 2A and the through hole 2B, and is engaged with a male thread portion 51A (described later) of the rotor shaft 51. The main valve element 3 is disposed within the guide hole 2A, and is guided by the guide hole 2A in the direction of the axis L in the forward and backward direction.

[0017] The main valve element 3 is configured to have a main valve portion 31 that seats on and releases from the main valve seat 13, and a retaining portion 32 that is a side wall of the main valve element 3 and holds the sub-valve element 4. A cylindrical opening 3A is formed inside the main valve portion 31. A cylindrical sub-valve chamber 3B is formed inside the retaining portion 32, and a retaining member 3C that holds a silencing member 37, described below, inside the main valve element 3. A cylindrical sub-valve port 3D is formed between the main valve portion 31 and the retaining portion 32, centered on the axis L, and opens from the sub-valve chamber 3B toward the opening 3A.

[0018] A communication passage 3E is formed on the side surface of the holding portion 32 of the main valve element 3, and opens toward the main valve chamber 1A in a direction intersecting the axis L. As shown in FIG. 3(A), a plurality of (e.g., eight) communication passages 3E are formed radially at rotationally symmetric positions around the axis L. The main valve element 3 has a retainer 33 at the upper end of the holding portion 32. The main valve element 3 also has a main valve spring 34 between the retainer 33 and the upper end of the guide hole 2A of the guide member 2. The main valve element 3 is biased toward the main valve seat 13 (closing direction) by the main valve spring 34. A sound-deadening member 35, which will be described later, is disposed inside the opening 3A of the main valve portion 31. The communication passages 3E are not limited to being formed radially at rotationally symmetric positions, and the number of communication passages 3E may be one or multiple communication passages 3E may be formed at uneven intervals.

[0019] The sub-valve element 4 is integrally provided at the lower end of the rotor shaft 51. The sub-valve element 4 is configured with a guide boss 41 and a needle valve 42. The tip of the needle valve 42 of the sub-valve element 4 is inserted in the axial direction L into the sub-valve port 3D, and a small flow rate of refrigerant is controlled by flowing through the gap between the needle valve 42 and the sub-valve port 3D. An annular washer 43 made of lubricating resin is disposed at the upper end of the guide boss 41, and the guide boss 41 is inserted into the retaining member 3C. The outer peripheral surface of the guide boss 41 is in sliding contact with the inner peripheral surface of the retaining member 3C and is guided therewith. The sub-valve element 4 and the rotor shaft 51 may be formed separately and then assembled together.

[0020] 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 sub-valve element 4 back and forth by the rotation of the stepping motor 5A, and a stopper mechanism 5C that restricts the rotation of the stepping motor 5A.

[0021] The stepping motor 5A is composed of a rotor shaft 51, a magnet rotor 52 rotatably disposed inside the case 14, a stator coil (not shown) disposed opposite the magnet rotor 52 on the outer periphery of the case 14, and other components such as a yoke and exterior members. The rotor shaft 51 is attached to the center of the magnet rotor 52 via a bushing, and a male thread portion 51A is formed on the outer periphery of the upper part of the rotor shaft 51. The male thread portion 51A is threadedly engaged with a female thread portion 2C of the guide member 2. As a result, the guide member 2 supports the rotor shaft 51 on the axis L. The female thread portion 2C of the guide member 2 and the male thread portion 51A of the rotor shaft 51 form a screw feed mechanism 5B.

[0022] A male-threaded guide groove 24A is formed on the outer peripheral surface of the stopper portion 24 of the guide member 2. A slider 53 is provided in the guide groove 24A. The slider 53 abuts against the magnet rotor 52 and rotates and moves up and down along the guide groove 24A as the magnet rotor 52 rotates. The slider 53 abuts against the upper or lower end of the guide groove 24A, thereby constituting a stopper mechanism 5C that restricts the rotation of the magnet rotor 52. The stopper mechanism 5C restricts the lowermost and uppermost positions of the rotor shaft 51 and magnet rotor 52.

[0023] With the above configuration, when the stepping motor 5A is driven, the magnet rotor 52 and rotor shaft 51 rotate, and the rotor shaft 51 moves together with the magnet rotor 52 in the direction of the axis L due to the screw feed mechanism 5B between the male thread portion 51A and the female thread portion 2C. Then, the sub-valve element 4 moves back and forth in the direction of the axis L, and the needle valve 42 of the sub-valve element 4 approaches or moves away from the sub-valve port 3D. Furthermore, when the sub-valve element 4 rises, the washer 43 engages with the retainer 33 of the main valve element 3 (sub-valve upper end position), and the main valve element 3 moves together with the sub-valve element 4, causing the main valve portion 31 of the main valve element 3 to unseat from the main valve seat 13. As a result, the main valve port 1B is fully opened, entering a large flow rate range state.

[0024] As shown in FIGS. 2 and 3 , a sub-valve seat 36 is formed around the sub-valve port 3D of the main valve element 3, with its axis L at its center. The sub-valve seat 36 is cylindrical and extends upward from the opening 3A. A groove-shaped annular space 3F is formed around the outer periphery of the sub-valve seat 36, recessed below the upper surface of the sub-valve seat 36. The annular space 3F is located radially inward and above the communicating passages 3E, is continuous around the axis L, and opens upward. As shown in FIG. 3A , the annular space 3F has an annular flow passage cross-sectional area. The annular space 3F has a flow passage cross-sectional area greater than the combined flow passage cross-sectional area of the eight communicating passages 3E. To ensure the deceleration of the fluid in the annular space 3F, as described below, the height of the annular space 3F is preferably equal to or greater than the radius of the communicating passages 3E. A sound-deadening member 37 is provided above the annular space 3F, and the upper opening of the annular space 3F is covered by the sound-deadening member 37.

[0025] Generally, sound-absorbing members are mainly made of porous materials such as sintered metal, laminated wire, or molded wire. However, when sound-absorbing members are made of metal materials, the following problems are of concern. These problems include erosion when fluid passes through, corrosion caused by impurities inside the piping, corrosion of the sound-absorbing member when the motor-operated valve is left alone in a humid or salt-damaged environment, and the possibility that hard metal foreign matter will become lodged in the valve when the sound-absorbing member peels off, causing clogging.

[0026] Therefore, in the motor-operated valve 10 of this embodiment, the silencing members 35, 37 are formed from a mesh-like or porous resin material. Resin materials with excellent chemical resistance, such as polytetrafluoroethylene resin (PTFE resin: Poly Tetra Fluoro Ethylene), polyphenylene sulfide resin (PPS resin: Poly Phenylene Sulfide Resin), polyethylene resin (PE resin: Poly Ethylene (USA), Poly Ethene (UK)), and polypropylene resin (PP resin: Poly Propylene), are preferred. Sintered resin (porous), multilayer nonwoven fabric, membrane, or other configurations are also desirable. Furthermore, in the motor-operated valve 10 of this embodiment, the silencing member 35 is formed in a cylindrical shape overall, and the silencing member 37 is formed in a ring shape overall.

[0027] The retaining member 3C is formed in a generally cylindrical shape and includes a fitting portion 38A at its upper end that protrudes radially outward and fits into the inner circumferential surface of the main valve element 3, a cylindrical guide portion 38B that extends along the inner circumferential surface of the main valve element 3 and guides the sub-valve element 4 in the direction of the axis L, a bottom portion 38C that extends radially inward from the lower end of the guide portion 38B, and a cylindrical extension portion 38D that extends downward from the radially inner side of the bottom portion 38C. The retaining member 3C is fixed by fitting the fitting portion 38A into the inner circumferential surface of the main valve element 3, and the sound absorbing member 37 is held by the bottom portion 38C. A narrow gap is formed between the lower end of the extension portion 38D and the upper surface of the sub-valve seat 36, and this gap defines a throttle passage 3G whose flow path cross-sectional area is smaller than that of the annular space 3F.

[0028] 2 and 3, when the motor-operated valve 10 is in the small flow rate control range, the main valve element 3 is seated on the main valve seat 13, the main valve port 1B is closed, and the needle valve 42 of the sub-valve element 4 controls the opening of the sub-valve port 3D to control the small flow rate. At this time, the refrigerant that flows into the main valve chamber 1A from the first joint pipe 11 enters the annular space 3F through the communicating passage 3E, as shown in FIGS. 3(A) and 3(B), and after swirling in the annular space 3F, bends upward in the direction of the axis L before passing through the silencer 37. Furthermore, as shown in FIG. 3(C), the refrigerant bends radially inward while passing through the silencer 37, passes through the throttle passage 3G, enters the sub-valve chamber 3B, and is throttled from the sub-valve chamber 3B by the gap between the needle valve 42 and the sub-valve port 3D.

[0029] 4 to 7 are enlarged cross-sectional views showing modified examples 1 to 4 of the motor-operated valve 10 of this embodiment, respectively. Modified examples 1 to 4 differ from the above-described embodiment in the shape of the holding member 3C and the refrigerant flow path.

[0030] 4, the holding member 3C of the first modification shown in FIG. 4 is provided such that the lower end of the extending portion 38D abuts against the upper surface of the sub-valve seat 36, and a throttle passage 3G having a smaller flow path cross-sectional area (total area) than the annular space 3F is formed by a through-hole provided in the middle of the extending portion 38D. In this first modification, as in the case described above, the refrigerant that has passed through the sound deadening member 37 passes through the throttle passage 3G, which is a through-hole, before entering the sub-valve chamber 3B.

[0031] 5, the retaining member 3C of Modified Example 2 is provided so that the lower end of the extension portion 38D abuts against the upper surface of the sub-valve seat 36, and a through-hole provided in the bottom portion 38C forms a throttle passage 3G whose flow path cross-sectional area (total area) is smaller than that of the annular space 3F. In this Modified Example 2, the refrigerant that has passed through the silencer member 37 flows upward, passes through the throttle passage 3G, which is a through-hole, in the direction of the axis L, enters the sub-valve chamber 3B, bends radially inward within the sub-valve chamber 3B, and then flows to the sub-valve port 3D.

[0032] 6 does not include a bottom portion 38C or an extension portion 38D, and the lower end of the guide portion 38B is held in contact with the silencer member 37. The sub-valve chamber 3B is provided with an expanded space 3H whose volume is larger than that of the annular space 3F. In this modified example 3, the refrigerant that passes through the silencer member 37 enters the expanded space 3H, bends radially inward within the expanded space 3H, and then flows into the sub-valve port 3D.

[0033] 7, a holding member 3C of Modified Example 4 is provided with an extension portion 38D whose lower end abuts against the upper surface of the sub-valve seat 36, and a through-hole 38E serving as a second communication passage is provided in the guide portion 38B. In this Modified Example 4, the refrigerant that has passed through the muffler member 37 bends radially outward, flows upward through the gap between the inner circumferential surface of the main valve body 3 and the guide portion 38B, passes radially through the through-hole 38E, and then enters the sub-valve chamber 3B. That is, a curved path 3J that bends radially outward and then further bends toward the axis L is provided between the annular space 3F and the sub-valve chamber 3B. The flow path cross-sectional area of the curved path 3J is smaller than the flow path cross-sectional area of the annular space 3F.

[0034] According to the present embodiment described above, even if the refrigerant in the main valve chamber 1A is in a state where liquid phase refrigerant is mixed with gas phase refrigerant, this refrigerant is decelerated by passing through the annular space 3F, and then passes through the sound-deadening member 37, the throttle passage 3G, the expanded space 3H, and the bent path 3J before entering the sub-valve chamber 3B, where it is stabilized. Therefore, the state of the refrigerant in the sub-valve chamber 3B is stabilized, and the refrigerant passing noise when passing through the gap between the needle valve 42 and the sub-valve port 3D is reduced, making it possible to suppress noise and vibration from the motor-operated valve 10.

[0035] According to this embodiment, in addition to the above-mentioned sound-deadening effect, because the sound-deadening members 35, 37 are made of resin, rust can be prevented, and the low hardness of the material reduces the attack of foreign matter on the valve portion (between the sub-valve seat 36 of the sub-valve port 3D and the needle valve 42 of the sub-valve body 4) when the sound-deadening members 35, 37 peel off, thereby suppressing corrosion caused by these factors. In addition, because the sound-deadening members 35, 37 are made of resin, there is a high degree of freedom in their shape, and they can be mass-produced by resin molding. Furthermore, resin materials have better vibration-damping properties than metals, so they are advantageous in terms of resistance to the effects of vibration, and good operability can be maintained.

[0036] FIG. 8 is an enlarged cross-sectional view showing essential parts of a motor-operated valve according to a second embodiment of the present invention. This second embodiment differs from the first embodiment in the shape of a retaining member 3C and the position of a sound-absorbing member 37. As shown in FIG. 8, the retaining member 3C includes a fitting portion 38A, a guide portion 38B, a bottom portion 38C, and a cylindrical extension portion 38D extending downward from a middle portion of the bottom portion 38C. The lower end of the extension portion 38D abuts against the upper surface of the sub-valve seat 36, and a through-hole 38E provided at the middle of the extension portion 38D forms a throttle passage whose cross-sectional area (total area) is smaller than that of the annular space 3F. The sound-absorbing member 37 is located radially inward of the extension portion 38D and is held between the bottom portion 38C of the retaining member 3C and the upper surface of the sub-valve seat 36.

[0037] In this motor-operated valve, as shown in Fig. 8, the refrigerant that flows into the main valve chamber 1A enters the annular space 3F from the communication passage 3E, swirls in the annular space 3F, bends upward in the direction of the axis L, bends radially inward, passes through the through hole 38E, and then passes through the silencer member 37. The refrigerant that has passed through the silencer member 37 enters the sub-valve chamber 3B, and is throttled from the sub-valve chamber 3B by the gap between the needle valve 42 and the sub-valve port 3D.

[0038] 9 to 11 are enlarged cross-sectional views showing Modified Examples 5 to 7 of the motor-operated valve 10 of this embodiment, respectively. These Modified Examples 5 to 7 differ from the second embodiment in the configuration of the retaining member 3C and the inclusion of a throttle member 39 that throttles the refrigerant from the annular space 3F. The throttle member 39 is a plate-shaped member provided to cover the upper opening of the annular space 3F, and is formed with through-holes 39A that penetrate vertically at multiple locations in the circumferential direction. That is, the through-holes 39A form throttle passages whose flow path cross-sectional area (total area) is smaller than that of the annular space 3F. These through-holes 39A may be provided in the same number as the communicating passages 3E and at the same positions in the circumferential direction, or may be provided at positions offset from the communicating passages 3E in the circumferential direction. The silencing member 37 is held between the retaining member 3C and the upper surface of the throttle member 39. That is, the throttle member 39 also functions as a first fixing member provided on the annular space 3F side of the silencing member 37, and the through-holes 39A form first through-holes.

[0039] A retaining member 3C of Modification 5 shown in FIG. 9 has a bottom 38C, which abuts against the upper surface of the muffler member 37, and the lower surface of the muffler member 37 abuts against the upper surface of the throttle member 39. That is, the bottom 38C presses the throttle member 39 toward the periphery of the upper opening of the annular space 3F via the muffler member 37. In Modification 5, the refrigerant from the annular space 3F is throttled by the through-hole 39A before entering the muffler member 37, and then bends radially inward within the muffler member 37 before entering the sub-valve chamber 3B. A retaining member 3C of Modification 6 shown in FIG. 10 does not have a bottom 38C, and the lower ends of the guide portions 38B abut against the upper surface of the muffler member 37, and the lower surface of the muffler member 37 abuts against the upper surface of the throttle member 39. That is, the lower ends of the guide portions 38B press the throttle member 39 toward the periphery of the upper opening of the annular space 3F via the muffler member 37. In this sixth modification, the refrigerant from the annular space 3F is throttled by the through-hole 39A before entering the silencer 37, and passes upward through the silencer 37 before entering the sub-valve chamber 3B. In the seventh modification shown in FIG. 11, the height (volume) of the silencer 37 is larger than in the case of FIG. 9, and the refrigerant is decelerated inside the silencer 37.

[0040] 12 and 13 are enlarged cross-sectional views showing modifications 8 and 9 of the motor-operated valve 10 of this embodiment, respectively. These modifications 8 and 9 differ from the above-described embodiment in that a fixing member 60 that holds the silencing member 37 is provided; the above-described washer 43 is omitted, and the holding member 3C is fixed within the holding portion 32 of the main valve body 3 by a retainer 33. The fixing member 60 has a first fixing member 61 provided inside the main valve body 3 on the annular space 3F side, and a second fixing member 62 provided on the opposite side of the first fixing member 61 with the silencing member 37 in between. The fixing member 60 holds the silencing member 37 between the first fixing member 61 and the second fixing member 62, sandwiching the silencing member 37 from both sides in the direction of the axis L, and holds the silencing member 37 when the second fixing member 62 is pressed downward in the direction of the axis L by the holding member 3C press-fitted into the main valve body 3.

[0041] The first fixing member 61 has a generally L-shaped cross section and includes a bottom 61A that abuts against the bottom surface of the sound deadening member 37 and covers the upper opening of the annular space 3F, and a wall 61B that faces and abuts against the radially inner side surface of the sound deadening member 37. The bottom 61A of the first fixing member 61 is provided with a plurality of first through holes 61C that communicate with the annular space 3F along the circumferential direction. These first through holes 61C function as throttle passages that throttle the refrigerant from the annular space 3F. The first through holes 61C may be the same in number as the communicating passages 3E and may be provided at the same circumferential positions as the communicating passages 3E, or may be provided at positions offset from the communicating passages 3E in the circumferential direction. At least one of the first fixing member 61 and the second fixing member 62 is an elastic member. In Modifications 8 and 9, the second fixing member 62 is an elastic member that is pressed against the sound deadening member 37 while being elastically deformed and crushed in the axial direction L by being pressed against the holding member 3C.

[0042] The radial width of the second fixed member 62 of Modification 8 shown in Fig. 12 is smaller than the radial width of the silencer member 37, and abuts against the outer peripheral upper surface of the silencer member 37. The inner peripheral upper surface of the silencer member 37 is not covered, and the refrigerant from the annular space 3F is throttled by the first through-hole 61C before entering the silencer member 37, rising inside the silencer member 37 and entering the sub-valve chamber 3B from a position more inner than the second fixed member 62, and bending radially inward within the sub-valve chamber 3B. The second fixed member 62 of Modification 9 shown in Fig. 13 is provided in abutment against substantially the entire upper surface of the silencer member 37, and is provided with a second through-hole 62A that communicates with the sub-valve chamber 3B. Furthermore, the height dimension of the wall portion 61B of the first fixed member 61 is smaller than the height dimension of the sound deadening member 37, the side surface of the sound deadening member 37 above the tip end (upper end) of the wall portion 61B is exposed, and a gap is provided between the upper end of the wall portion 61B and the radially inner end of the second fixed member 62. In this 9th modification, the refrigerant from the annular space 3F is throttled by the first through-hole 61C before entering the sound deadening member 37, passes upward through the sound deadening member 37, and is throttled again by the second through-hole 62A before entering the sub-valve chamber 3B. Furthermore, some of the refrigerant that has passed through the sound deadening member 37 may enter the sub-valve chamber 3B through the gap between the upper end of the wall portion 61B of the first fixed member 61 and the radially inner end of the second fixed member 62.

[0043] According to the above-described eighth and ninth modifications, the sound deadening member 37 is sandwiched and held between the first fixing member 61 and the second fixing member 62 of the fixing member 60, thereby improving the holding strength of the sound deadening member 37. Furthermore, the wall portion 61B of the first fixing member 61 abuts against the radially inner side surface of the sound deadening member 37, thereby improving the holding strength of the sound deadening member 37 in the radial direction. In particular, as in the ninth modification, the refrigerant is dispersed by branching into a flow path that passes upward through the sound deadening member 37 and enters the sub-valve chamber 3B via the second through-hole 62A, and a flow path that passes radially through the wall portion 61B (i.e., via the gap between the upper end of the wall portion 61B and the second fixing member 62) and enters the sub-valve 3B, thereby improving quietness. Furthermore, the first through-hole 61C functions as a throttle passage whose cross-sectional area (total area) is smaller than that of the annular space 3F, thereby stabilizing the state of the refrigerant in the sub-valve chamber 3B. Furthermore, by making at least one of the first fixing member 61 and the second fixing member 62 out of an elastic member, the sound deadening member 37 can be pressed and held in the direction of the axis L, thereby further improving the holding ability of the sound deadening member 37.

[0044] In the present embodiment, the refrigerant is decelerated as it passes through the annular space 3F, is further throttled by the through holes 38E, 39A, and the first through hole 61C, passes through the muffler 37, and then enters the sub-valve chamber 3B, where it is stabilized. Furthermore, as in the ninth modification, the refrigerant that has passed through the muffler 37 is throttled by the second through hole 62A of the second fixed member 62 and the gap between the upper end of the wall portion 61B of the first fixed member 61 and the second fixed member 62, where it enters the sub-valve chamber 3B, where it is stabilized. Therefore, the state of the refrigerant in the sub-valve chamber 3B is stabilized, reducing refrigerant passing noise as it passes through the gap between the needle valve 42 and the sub-valve port 3D, thereby suppressing noise and vibration from the motor-operated valve 10. Moreover, because the mufflers 35, 37 are made of resin as described above, the same effects as those of the first embodiment can be obtained.

[0045] 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. The motor-operated valve of the present invention may be used in air conditioners such as residential air conditioners and commercial air conditioners, and is not limited to air conditioners but can also be applied to various types of refrigerators, etc.

[0046] In the electric valve 10 of the above embodiment, the sub-valve seat 36 and the sub-valve port 3D are formed integrally with the main valve body 3, but this is not limited to this. A valve seat member having a sub-valve port may be provided separately from the main valve body, and the valve seat member may be assembled to the main valve body.

[0047] Furthermore, in the motor-operated valve 10 of the above embodiment, a retaining member 3C is provided inside the main valve body 3, and this retaining member 3C guides the sub-valve body 4 and also retains the silencing member 37. However, this is not limiting, and the guide portion 38B that guides the sub-valve body 4 may be eliminated from the retaining member 3C, and the sub-valve body may be guided by the inner circumferential surface of the main valve body. Furthermore, the retaining member that holds the silencing member 37 may be composed of a washer-shaped member.

[0048] Furthermore, the drive unit 5 of the electric valve 10 in the above embodiment is equipped with a stepping motor 5A, a screw feed mechanism 5B, and a stopper mechanism 5C, but the configuration of each of these parts is not limited to that of the above embodiment, and any type of mechanism can be adopted.

[0049] The embodiments of the present invention have been described in detail above with reference to the drawings, but the specific configurations are 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]

[0050] 1 Valve housing (valve body) 1A Main valve chamber 1B Main valve port 2 Guide member 3 Main valve body 3B Sub-valve chamber 3C holding member 3D Sub-Valve Port 3E communication path 3F circular space 3G Aperture Passage 3H Expanded Space 3J curved road 4 Sub-valve body 37 Sound deadening materials 38E Through hole (throttle passage, second communication passage) 39 Squeezing member (first fixed member) 39A Through hole (throttling passage, first through hole) 42 Needle valve 60 Fixing member 61 First fixing member 61A bottom 61B Wall section 61C First through hole (throttle passage) 62 Second fixing member 62A Second through hole (throttling passage)

Claims

1. a main valve body defining a main valve chamber and a main valve port; a main valve element provided within the main valve chamber for opening and closing the main valve port; and a sub-valve element provided in a sub-valve chamber formed within the main valve element and movable in an axial direction, wherein the main valve element closes the main valve port, and the opening of a sub-valve port provided in the main valve element is controlled by a needle valve of the sub-valve element, thereby providing a small flow rate control range for throttling a flow rate of a fluid in a gap between the needle valve and the sub-valve port, The main valve body is formed with a communication passage that opens toward the main valve chamber, and an annular space that is continuous around the axis between the communication passage and the sub-valve chamber, a resin sound-deadening member that allows the fluid to pass through is provided between the communication passage and the sub-valve port; a sub-valve seat is formed around the sub-valve port and is centered on the axis; The motor-operated valve is characterized in that the annular space is formed on the outer periphery of the sub-valve seat and has a groove shape recessed below an upper surface of the sub-valve seat.

2. 2. The motor-operated valve according to claim 1, wherein the annular space is located radially inward and above the communication passage, is continuous in an annular shape around the axis, and is formed so as to be open upward but not open downward.

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