Motorised valve

Abstract

The present application provides an electric valve capable of suppressing noise when fluid passes through a sub valve port at low cost. By arranging a force applying spring (9) at a position covering a communication passage (411A), when fluid passes through the communication passage (411A), the fluid passes through the coil (91) upstream of the communication passage between each other, pressure loss is generated to reduce the speed of the fluid, and the noise when the fluid passes through the sub valve port (42a) can be reduced. At this time, by using the force applying spring (9) to apply force to the main valve core (4) in the closing direction, the action of the main valve core (4) in the axial direction can be stabilized. That is, the force applying spring (9) has the dual functions of reducing noise and stabilizing action, and since no other spring member is arranged for the purpose of stabilizing action, the number of parts can be reduced to achieve low cost.

Description

TECHNICAL FIELD

[0001] The present application relates to an electric valve. BACKGROUND

[0002] In the past, as an electric valve, a flow adjustment valve has been proposed which has a main valve core portion and a sub valve core portion, and is capable of being in a small flow control state or a large flow control state (for example, refer to Patent Literature 1). In the flow adjustment valve described in Patent Literature 1, a sound deadening member is provided to cover a communication hole that communicates the inside and outside of a valve body main portion. The sound deadening member is composed of an elastic body, and is held to the valve body main portion in a restored state, achieving reduction in assembly work hours.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2020-56472 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] However, in a structure in which a sound deadening member is additionally provided as described in Patent Literature 1, it is possible to reduce noise when fluid passes through a sub valve port, but on the other hand, cost is likely to increase due to an increase in the number of parts. That is, it is difficult to suppress noise at low cost.

[0008] An object of the present application is to provide an electric valve that can suppress noise when fluid passes through a sub valve port at low cost.

[0009] MEANS FOR SOLVING THE PROBLEMS

[0010] The electric valve of the present application has a valve body that constitutes a main valve chamber and a main valve port, a main valve core that adjusts an opening area between a main valve seat of the main valve port, and a sub valve core that is provided in a sub valve chamber formed in the main valve core so as to be movable in an axial direction, and adjusts an opening area between a sub valve seat of a sub valve port provided to the main valve core, characterized in that the main valve core has a cylinder portion that is formed with a communication passage that communicates the main valve chamber and the sub valve chamber, and a biasing spring is disposed at a position along an inner peripheral surface or an outer peripheral surface of the cylinder portion, the biasing spring applying a force to the main valve core in a valve closing direction.

[0011] According to the present application described above, by providing the urging spring at a position covering the communication passage, when fluid passes through the communication passage, the fluid passes through the coils (one turn of the spring) of the urging spring on the upstream side or the downstream side of the communication passage. Thus, pressure loss can be generated to reduce the speed of the fluid, and the noise when the fluid passes through the sub valve port can be reduced. At this time, by urging the main valve spool in the valve closing direction by the urging spring, the operation of the main valve spool in the axial direction can be stabilized. That is, the urging spring has both the effects of reducing noise and stabilizing the operation. Therefore, according to the present application, compared with a structure in which a member for reducing noise and a member for stabilizing the operation are provided separately, the number of parts can be reduced to achieve cost reduction.

[0012] At this time, in the electric valve of the present application, preferably, the gap between the outer peripheral surface of the cylinder portion and the inner peripheral surface of the urging spring, or the gap between the inner peripheral surface of the cylinder portion and the outer peripheral surface of the urging spring is equal to or smaller than the effective diameter of the communication passage. According to such a structure, the urging spring can be arranged in close proximity to the communication passage, and the fluid flowing into the communication passage or the fluid flowing out of the communication passage changes the flow direction by the urging spring, so the speed of the fluid easily decreases, and the noise easily decreases. In addition, in the case where the cross section of the communication passage is circular, the effective diameter of the communication passage is the diameter of the circle, and in the case where the shape other than the circle, the diameter of the circle having an area equal to the cross section is the effective diameter.

[0013] In addition, in the electric valve of the present application, preferably, the coil gap of the urging spring when the main valve spool is seated on the main valve seat is smaller than the effective diameter of the communication passage. According to such a structure, the pressure loss easily increases to reduce the speed of the fluid, and the noise more easily decreases. In addition, the so-called coil gap refers to the interval between the adjacent coils in the axial direction.

[0014] In addition, in the electric valve of the present application, preferably, a guide member having a guide hole coaxially provided with the main valve port and guiding the main valve spool is provided, and the cylinder portion is slidably arranged in the guide hole. According to such a structure, the main valve spool urged by the urging spring is slidably guided by the guide hole, so the inclination of the main valve spool can be suppressed, and the valve closing performance can be improved.

[0015] In addition, in the electric valve of the present application, preferably, the urging spring is arranged outside the cylinder portion. According to such a structure, compared with a structure in which the urging spring is arranged inside the cylinder portion, the urging spring can be made large in diameter. Thus, the deformation other than the axial direction such as tilting in the urging spring can be suppressed, and the valve closing performance can be improved.

[0016] Further, in the electric valve of the present application, it is preferable that the main valve spool has a flange portion which is expanded in diameter on the main valve seat side, and the urging spring imparts a valve-closing direction force to the flange portion. According to such a structure, by directly applying the urging force to the main valve spool, the acting force can be easily transmitted, and the valve-closing performance can be improved.

[0017] Effects of Invention

[0018] According to the electric valve of the present application, the noise at the time of passage of fluid through the sub valve port can be suppressed at low cost. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a sectional view of an electric valve which is an embodiment of the present application.

[0020] Figure 2 is an enlarged sectional view of a main part of the above electric valve.

[0021] Figure 3 is an enlarged partial sectional view of a main part of the above electric valve.

[0022] Figure 4 is an enlarged sectional view of a main part of an electric valve of a modified example of the present application.

[0023] In the drawings:

[0024] 1 - electric valve; 2 - valve body; 23 - main valve seat; 23a - main valve port; 2R - main valve chamber; 4 - main valve spool; 3 - guide member; 32a - guide hole; 411 - cylindrical portion; 411A - communication passage; 411B - outer peripheral surface; 411C - inner peripheral surface; 42 - inner side cylindrical portion (sub valve seat); 42a - sub valve port; 4R - sub valve chamber; 45 - flange portion; 5 - sub valve spool; 9 - urging spring. DETAILED DESCRIPTION

[0025] An embodiment of the present application will be described with reference to the drawings. The electric valve 1 of the present embodiment is used for a refrigeration cycle system of an air conditioning machine such as a cabinet type air conditioner, a room air conditioner, and the like, as shown in Figure 1 , and is provided with a valve body 2, a guide member 3, a main valve spool 4, a sub valve spool 5, a drive portion 6, a first sound deadening member 7, a second sound deadening member 8, and an urging spring 9. The main valve spool 4 and the sub valve spool 5 are disposed so as to move in a predetermined axial direction, and hereinafter, the axial direction will be referred to as the Z direction, two directions orthogonal to the Z direction will be referred to as the X direction and the Y direction, and the up and down in the Z direction will be referred to as the reference. Further, the direction toward the lower side in the Z direction becomes the valve-closing direction, and the direction toward the upper side becomes the valve-opening direction. Figure 1

[0026] ​The valve body 2 is, for example, a valve housing formed in a substantially cylindrical shape from brass, stainless steel, or the like, and has a main valve chamber 2R on the inner side thereof. The valve body 2 has a first port 21 that is open on one side in the X direction and a second port 22 that is open on the lower side in the Z direction on the side surface thereof. A first joint pipe 11 that extends in the X direction is connected to the first port 21, and a second joint pipe 12 that extends in the Z direction is connected to the second port 22, and the first joint pipe 11 and the second joint pipe 12 communicate with the main valve chamber 2R. The first joint pipe 11 and the second joint pipe 12 can be fixed to the valve body 2, for example, by brazing or the like.

[0027] A cylindrical main valve seat 23 that projects toward the main valve chamber 2R (toward the upper side) with the Z direction as the axis direction is formed on the lower end portion of the valve body 2, and the inner side of the main valve seat 23 becomes a main valve port 23a, which communicates with the second port 22. That is, the second joint pipe 12 is communicated with the main valve chamber 2R via the main valve port 23a. In the present embodiment, the electric valve 1 is used in a manner in which the first port 21 is the primary side and the second port 22 is the secondary side, and the fluid (refrigerant) that flows into the main valve chamber 2R from the first joint pipe 11 flows out from the second joint pipe 12, but the electric valve 1 can also be assembled in a cycle in which the fluid can flow in both directions.

[0028] The guide member 3 is installed to the opening portion of the upper end of the valve body 2, and has a press-in portion 31 that is pressed into the inner peripheral surface of the valve body 2, a substantially cylindrical guide portion 32 that is located on the inner side of the press-in portion 31, a bracket portion 33 that is provided so as to extend to the upper portion of the guide portion 32, a stop portion 34 that is provided above the bracket portion 33, and a ring-shaped flange portion 35 that is located on the outer periphery of the guide portion 32. The press-in portion 31, the guide portion 32, the bracket portion 33, and the stop portion 34 are configured as a one-piece member made of resin. In addition, the flange portion 35 is, for example, a metal plate made of brass, stainless steel, or the like, and is integrally provided with the press-in portion 31 and the bracket portion 33 made of resin by insert molding.

[0029] The guide member 3 is assembled to the valve body 2, and the flange portion 35 is fixed to the upper end portion of the valve body 2 by welding or the like. In addition, a cylindrical guide hole 32a that is coaxial with the main valve port 23a and that has the Z direction as the axis direction is formed in the guide portion 32 of the guide member 3, and a through-hole 33a that is coaxial with the guide hole 32a is formed in the center of the bracket portion 33. In addition, an internally threaded portion (threaded hole) 34a that is coaxial with the guide hole 32a and the through-hole 33a is formed in the center of the stop portion 34.

[0030] As Figure 2As shown, the guide member 3 has a reduced diameter portion 36 at the lower end of the guide portion 32, which has an outer diameter that is smaller than other portions, and the urging spring 9 is arranged on the outer side of the reduced diameter portion 36. A step portion 37 is formed between the reduced diameter portion 36 and the portion on the upper side thereof, and the upper end portion of the urging spring 9 abuts against the face in the step portion 37 that faces the lower side (the main valve seat 23 side).

[0031] The main valve spool 4 adjusts the opening area between the main valve seat 23 and the main valve port 23a. The main valve spool 4 is guided in the Z direction by being arranged in the guide hole 32a of the guide portion 32, and is formed as a whole in a cylindrical shape with the Z direction as the axis direction. The main valve spool 4 integrally has an outer side cylindrical portion 41 formed as a bottomed cylindrical shape, an inner side cylindrical portion 42 arranged on the inner side of the outer side cylindrical portion 41, and a main valve portion 43 that approaches or separates with respect to the main valve seat 23.

[0032] The outer side cylindrical portion 41 has a cylindrical portion 411 and a bottom portion 412 provided at the lower end portion of the cylindrical portion 411. The cylindrical portion 411 is a portion that is slidably arranged in the guide hole 32a and guided thereby. The bottom portion 412 extends along the XY plane. The inside of the outer side cylindrical portion 41, which is a bottomed cylindrical shape, becomes the sub valve chamber 4R. The inner peripheral surface of the pressing member 73 described later, which is arranged on the inner side of the cylindrical portion 411, functions as a needle guide hole. The guide boss portion 53 fixed to the valve shaft 51 described later is inserted through this needle guide hole, and the annular retainer 44 is fixed to the upper end of the cylindrical portion 411 by fitting or welding, or the like. In the example shown, there is a shape in which the spring member can be arranged between the upper end portion of the guide hole 32a and the retainer 44, but it can also be a shape that does not become such.

[0033] The inner side cylindrical portion 42 extends from the central portion of the bottom portion 412 toward the side (upper side) opposite the main valve port 23a, and is a sub valve seat portion in which the sub valve spool 5 approaches or separates. The sub valve port 42a, which is a through hole, is formed on the inner side of the inner side cylindrical portion 42. The annular space 421, which is a circular ring shape, is formed on the outer side of the inner side cylindrical portion 42.

[0034] A plurality of (for example, eight) communication passages 411A that communicate the inside and outside of the cylindrical portion 411 are formed in the cylindrical portion 411 of the outer side cylindrical portion 41. The eight communication passages 411A are arranged at equal intervals in the circumferential direction centered on the Z direction, and communicate with the annular space 421. By forming the communication passages 411A in the cylindrical portion 411, the main valve chamber 2R, the sub valve chamber 4R, the sub valve port 42a, and the main valve port 23a are communicated. In the example shown, the communication passages 411A are formed in the lower end portion (i.e., the boundary portion with the bottom portion 412) in the cylindrical portion 411, but "formed in the cylindrical portion" with respect to the communication passages means that at least a portion of the communication passages is formed in the cylindrical portion, and also includes a shape in which the communication passages span portions other than the cylindrical portion.

[0035] Further, at a position in the outer cylindrical portion 41 where the communication passage 411A is formed in the Z direction center, an inclined surface 413 is formed which is continuous with the communication passage 411A and continuous with the lower surface of the annular space 421. That is, as shown in Figure 2 the inclined surface 413 appears in a cross-sectional view passing through the communication passage 411A, but does not appear in a cross-section not passing through the communication passage 411A. The inclined surface 413 is inclined in a manner that it faces upward as it moves from the lower surface of the communication passage 411A toward the inner peripheral side, and is connected with the lower surface of the annular space 421. Thereby, when viewed in the radial direction, the communication passage 411A overlaps with the annular space 421, and the annular space 421 is disposed slightly offset upward.

[0036] The main valve portion 43 is formed in a substantially cylindrical shape in a manner that the cylindrical portion 411 of the outer cylindrical portion 41 is extended downward. The main valve portion 43 is provided in a manner that it seats (comes into contact with) the main valve seat 23 in the fully closed state.

[0037] In the main valve spool 4, the portion including the main valve portion 43 (the portion on the main valve seat 23 side) is expanded in diameter, and a flange portion 45 is formed. The main valve spool 4 has a reduced diameter portion 46 having an outer diameter smaller than that of the flange portion 45 on the upper side of the flange portion 45, and the urging spring 9 is disposed on the outer side of the reduced diameter portion 46. A step portion 47 is formed between the flange portion 45 and the reduced diameter portion 46, and the lower end portion of the urging spring 9 comes into contact with the face in the step portion 47 that faces upward (the side opposite to the main valve seat 23).

[0038] In this way, the urging spring 9 is disposed between the lower surface of the step portion 37 of the guide member 3 fixed to the valve main body 2 and the upper surface of the step portion 47 of the main valve spool 4, and the main valve spool 4 is urged in the valve closing direction by the urging spring 9. That is, the urging spring 9 exerts a force in the valve closing direction on the flange portion 45 in the main valve spool 4. The urging spring 9 is always disposed between the lower surface of the step portion 37 and the upper surface of the step portion 47 in a state of being compressed from the natural state.

[0039] The sub valve spool 5 is a needle valve, and is provided to the lower end portion of the rotor shaft 61 described later, and integrally has a valve shaft 51 connected to the rotor shaft 61 side and a needle portion 52 connected to the lower end of the valve shaft 51. The sub valve spool 5 also has a guide boss portion 53 fixed to the valve shaft 51. The guide boss portion 53 is fixed separately from the valve shaft 51, but the guide boss portion 53 can also be formed integrally with the valve shaft 51. The guide boss portion 53 is slidably inserted into a needle guide hole formed by the pressing member 73.

[0040] The drive unit 6 is provided inside and outside of a housing 24 fixed to the upper end of the valve body 2, and has a stepping motor 6A, a screw feed mechanism 6B that advances and retreats the sub valve element 5 by rotation of the stepping motor 6A, and a stop mechanism 6C that limits the rotation of the stepping motor 6A. The housing 24 is airtightly fixed to the valve body 2 by welding or the like, for example.

[0041] The stepping motor 6A is constituted by a rotor shaft 61, a magnetic rotor 62 rotatably disposed inside the housing 24, a stator coil 63 disposed in opposition to the magnetic rotor 62 on the outer periphery of the housing 24, and a magnetic yoke, an outer member, and the like not shown. The rotor shaft 61 is mounted to the center of the magnetic rotor 62 via a bush, and an external thread portion 61a is formed on the outer periphery of the rotor shaft 61 on the side of the guide member 3. This external thread portion 61a is screwed with the internal thread portion 34a of the guide member 3, whereby the guide member 3 supports the rotor shaft 61 on the axis in the Z direction. Also, the internal thread portion 34a of the guide member 3 and the external thread portion 61a of the rotor shaft 61 constitute the screw feed mechanism 6B.

[0042] The first sound deadening member 7 is integrally formed in a circular ring shape so that the valve shaft 51 and the needle portion 52 can pass therethrough, and is disposed in the flow path from the communication passage 411A to the sub valve port 42a. The first sound deadening member 7 is a filter formed in a three-dimensional mesh shape by randomly bending a linear member. The first sound deadening member 7 is, for example, a mist eliminator. The first sound deadening member 7 formed in a mesh shape functions to subdivide the flow path, and the fluid (refrigerant) passes through the first sound deadening member 7 while being subdivided. That is, when the fluid in a gas-liquid mixed state passes through the first sound deadening member 7, the bubbles are subdivided. At this time, the first sound deadening member 7 has various sizes of passable areas as a member that is a passage through which the fluid can pass, since the linear member is randomly bent. In addition, when the fluid passes through the inside of the first sound deadening member 7 in a predetermined passage direction, the passable area changes depending on the passage direction position. Thus, bubbles of various sizes are subdivided.

[0043] The first silencing member 7 is fixed in the cylindrical portion 411 of the main valve spool 4 by a pair of fixing members 71A, 71B and a pressing member 73. The first silencing member 7 is sandwiched from the Z direction by the pair of fixing members 71A, 71B, and the pressing member 73 is arranged on the upper side of the fixing member 71A. The first silencing member 7, the fixing members 71A, 71B, and the pressing member 73 are sandwiched from the Z direction by the inner cylindrical portion 42 and the retainer 44, and the outer periphery of the fixing members 71A, 71B is in contact with the inner peripheral surface of the cylindrical portion 411, and the first silencing member 7, the fixing members 71A, 71B, and the pressing member 73 are fixed. At this time, the first silencing member 7 is arranged on the upper side in such a manner that the annular space 421 is aligned in the Z direction. A plurality of through holes extending in the Z direction are formed in each of the pair of fixing members 71A, 71B. Thereby, the annular space 421 communicates with the space in which the first silencing member 7 is arranged, and the space in which the first silencing member 7 is arranged communicates with the sub valve chamber 4R. That is, when fluid flows from the annular space 421 into the sub valve chamber 4R, it necessarily passes through the first silencing member 7. The pressing member 73 is formed in a cylindrical shape as a whole, thereby functioning as a pressing portion for pressing the first silencing member 7 as described above, and has a fitting portion 731 in which the inner diameter is reduced (reduced in diameter) at the upper end portion, and is capable of being fitted with the guide boss portion 53 of the sub valve spool 5 in the fitting portion 731. In addition, the pressing member 73 is composed of, for example, a sliding member of PPS resin or the like. Thereby, when the guide boss portion 53 of, for example, metal (stainless steel) slides with respect to the inner peripheral surface of the pressing member 73, and is fitted with the fitting portion 731, the sliding resistance can be suppressed.

[0044] In addition, in the present embodiment, the first silencing member 7 is fixed in the cylindrical portion 411 of the main valve spool 4 using the fixing member 71A and the fixing member 71B, but either one of them can be used alone, and the first silencing member 7 can be fixed using only the pressing member 73 without using the fixing members 71A, 71B.

[0045] The second silencing member 8 is arranged in the flow path from the sub valve port 42a to the main valve port 23a, that is, at a position downstream of the first silencing member 7 in the case where the first port 21 is the primary side. The second silencing member 8 is, like the first silencing member 7, a filter formed in a three-dimensional mesh shape by randomly bending a linear member, and is, for example, a mist eliminator. The first silencing member 7 preferably has a higher density than the second silencing member 8, but is not limited thereto, and the densities of both can be equal, and the second silencing member 8 can have a higher density than the first silencing member 7. Here, the density refers to the mass per unit volume, and the higher the density, the higher the performance of subdividing bubbles.

[0046] The second silencing member 8 is arranged so as to fit into (without a gap) the inside of the cylindrical main valve portion 43, and is thus opposed to the sub valve port 42a in the Z direction. Thus, when fluid that has passed through the sub valve port 42a flows into the main valve port 23a, it must pass through the second silencing member 8. The second silencing member 8 can be fixed by riveting, for example, via a ring-shaped member, to the lower end portion of the main valve portion 43.

[0047] Here, the details of the opening and closing operation of the main valve spool 4 and the sub valve spool 5 in the electric valve 1 will be described. If the magnetic rotor 62 and the rotor shaft 61 are rotated by the drive of the stepping motor 6A, the rotor shaft 61 is moved in the Z direction by the screw feed mechanism 6B of the outer threaded portion 61a of the rotor shaft 61 and the inner threaded portion 34a of the guide member 3. Thus, the sub valve spool 5 is moved in and out in the Z direction to approach or move away from the sub valve port 42a, and the valve opening degree of the sub valve port 42a is controlled (small flow control). In addition, the guide boss portion 53 of the sub valve spool 5 is engaged with the engagement portion 731 of the pressing member 73, and the main valve spool 4 moves together with the sub valve spool 5 to approach or move away from the main valve seat 23 (large flow control). Thus, the flow rate of the refrigerant flowing from the first joint pipe 11 to the second joint pipe 12 is controlled. In this embodiment, in a state in which the sub valve spool 5 is moved in and out in the Z direction to most closely approach the sub valve seat portion having the sub valve port 42a, the sub valve spool 5 does not abut (seat) on the sub valve seat portion, and a gap is formed between the sub valve spool 5 and the sub valve seat portion to allow fluid to pass through the sub valve port 42a, but the sub valve spool 5 can also be configured to seat on the sub valve seat portion.

[0048] An outer threaded guide groove 34b is formed in the outer peripheral surface of the stop portion 34 of the guide member 3, and a slider 64 is provided in the guide groove 34b. The slider 64 abuts on the magnetic rotor 62, and rotates along the guide groove 34b and moves up and down in conjunction with the rotation of the magnetic rotor 62. Furthermore, the slider 64 constitutes a stop mechanism 6C that limits the rotation of the magnetic rotor 62 by abutting on the upper end or the lower end of the guide groove 34b. By this stop mechanism 6C, the lowermost position and the uppermost position of the rotor shaft 61 and the magnetic rotor 62 are limited.

[0049] Next, the relationship between the main valve spool 4 and the urging spring 9 and the operation when fluid flows from the main valve chamber 2R into the sub valve chamber 4R will be described with reference to FIG. 9. Figure 2 3 The relationship between the main valve spool 4 and the urging spring 9 and the operation when fluid flows from the main valve chamber 2R into the sub valve chamber 4R will be described with reference to FIG. 9. First, the urging spring 9 is arranged along the outer peripheral surface 411B of the cylindrical portion 411 and covers the communication passage 411A. That is, the urging spring 9 is arranged outside the cylindrical portion 411. Here, "the urging spring 9 covers the communication passage 411A" means a positional relationship in which the communication passage 411A is hidden when the urging spring 9 is assumed to be cylindrical. The communication passage 411A is located at a position that is higher than the step portion 47. In addition, the urging spring 9 is arranged coaxially with the cylindrical portion 411 in the Z direction.​

[0050] The urging spring 9 is a member in which a wire is bent into a spiral shape, and is composed of a plurality of coils 91. One coil 91 refers to the amount of one turn of the wire. In the urging spring 9, the coils 91 arranged in the Z direction are arranged at a predetermined interval from each other, and the interval is referred to as a coil gap C. The coil gap C refers to the interval between the lower end of the upper coil 91 and the upper end of the lower coil 91 of the two adjacent coils 91.

[0051] In the present embodiment, the communication passage 411A is circular in cross section. The coil gap C of the urging spring 9 when the main valve spool 4 is seated on the main valve seat 23 is smaller than the inner diameter (diameter) D of the communication passage 411A. If the main valve spool 4 is unseated from the main valve seat 23, the urging spring 9 is compressed, and the coil gap C becomes smaller, so the coil gap C is always smaller than the inner diameter D regardless of the position of the main valve spool 4. In addition, the communication passage 411A is not limited to being circular in cross section. In the case where the cross-sectional shape of the communication passage 411A is other than circular, the coil gap C of the urging spring 9 when the main valve spool 4 is seated on the main valve seat 23 only needs to be smaller than the effective diameter of the communication passage 411A. The effective diameter of the communication passage 411A refers to the diameter of a circle having an area equal to the cross section of the communication passage 411A. For example, in the case where the cross section of the communication passage 411A is square, the diameter of a circle having an area equal to the square becomes the effective diameter. In addition, the gap between the outer peripheral surface 411B of the cylindrical portion 411 and the inner peripheral surface of the urging spring 9 is equal to or smaller than the inner diameter D (i.e., the effective diameter) of the communication passage 411A.

[0052] Since the urging spring 9 is provided at a position along the outer peripheral surface 411B of the cylindrical portion 411 and covering the communication passage 411A, when fluid flows from the main valve chamber 2R to the sub valve chamber 4R through the communication passage 411A, the fluid passes between the adjacent coils 91. In this way, when the fluid passes between the coils 91, the flow passage cross-sectional area becomes smaller, so the flow velocity temporarily increases. After the fluid passes between the coils 91, the flow passage cross-sectional area becomes larger again, so the flow velocity decreases. In this way, the fluid passes through a flow passage in which the flow passage cross-sectional area temporarily becomes small, so pressure loss occurs. Therefore, the flow velocity of the fluid after passing between the coils 91 is lower than before. The smaller the coil gap C, the greater the pressure loss, and the flow velocity at the end is likely to decrease. Furthermore, the more the coils 91 overlap the communication passage 411A (from the direction along the XY plane, the communication passage 411A is blocked by the coils 91), the greater the pressure loss.

[0053] As described above, by providing the urging spring 9, the fluid is decelerated and flows into the sub valve chamber 4R. When the fluid passes between the sub valve port 42a and the sub valve spool 5, the fluid acts on the sub valve spool 5, so the sub valve spool 5 vibrates. The excitation force of the vibration at this time corresponds to the flow velocity of the fluid. Therefore, by decelerating the fluid, the vibration of the sub valve spool 5 is suppressed, and the passing sound of the fluid is reduced.

[0054] In the electric valve 1 at the time of small flow control, the sound deadening members 7, 8 function as described below. First, fluid flows into the main valve chamber 2R from the first port 21. This fluid sometimes contains bubbles and becomes a gas-liquid mixed state, and hereinafter, description will be made in a manner that bubbles are contained. The fluid that has flowed into the main valve chamber 2R passes through the coils 91 of the biasing spring 9 and the communication passage 411A to flow into the fluid in the sub valve chamber 4R. At this time, the fluid that has passed through the communication passage 411A circulates in the annular space 421 and then reaches the sub valve chamber 4R by passing through the through hole of the fixed member 71B, the first sound deadening member 7, and the through hole of the fixed member 71A. When the fluid flows toward the annular space 421 through the communication passage 411A, the direction of flow becomes a direction along the XY plane. On the other hand, when the fluid flows from the annular space 421 toward the first sound deadening member 7, the direction of flow is along the Z direction. That is, the direction of flow is bent by substantially a right angle, and the flow rate of the fluid that passes through the coils 91 of the biasing spring 9 is further reduced.

[0055] As described above, the fluid passes through the first sound deadening member 7, and the bubbles are subdivided. Further, the fluid passes through the second sound deadening member 8 toward the main valve port 23a after the flow is throttled by the sub valve port 42a. At this time, it is preferable that the density of the second sound deadening member 8 be lower than that of the first sound deadening member 7, and according to such a structure, the fluid is less likely to be trapped in the second sound deadening member 8.

[0056] According to the present embodiment described above, by disposing the biasing spring 9 at a position that covers the communication passage 411A, when the fluid passes through the communication passage 411A, the fluid passes through the coils 91 of the biasing spring 9 on the upstream side of the communication passage, pressure loss occurs, and the velocity of the fluid is reduced, and it is possible to reduce the noise when the fluid passes through the sub valve port 42a. At this time, by using the biasing spring 9 to apply a force to the main valve element 4 in the closing direction, it is possible to stabilize the operation of the main valve element 4 in the axial direction. That is, the biasing spring 9 has both the effects of reducing noise and stabilizing the operation, and since there is no other spring member provided for the purpose of stabilizing the operation, it is possible to reduce the number of parts and achieve cost reduction.

[0057] Further, the gap between the outer peripheral surface 411B of the cylindrical portion 411 and the inner peripheral surface of the biasing spring 9 is equal to or less than the inner diameter D of the communication passage 411A, and thus it is possible to dispose the biasing spring 9 in close proximity to the communication passage 411A, and the fluid that has flowed into the communication passage 411A or the fluid that has flowed out of the communication passage changes the direction of flow by the biasing spring 9, and thus the velocity of the fluid is easily reduced, and it is easy to reduce noise.

[0058] Further, the coil gap C of the biasing spring 9 when the main valve element 4 is seated on the main valve seat 23 is smaller than the inner diameter D of the communication passage 411A, and thus it is easy to increase pressure loss and reduce the velocity of the fluid, and it is further easy to reduce noise.

[0059] Further, the main valve spool 4 to which the urging spring 9 applies a force is slidably arranged in the guide hole 32a, and is guided by the guide hole 32a, so that inclination of the main valve spool 4 can be suppressed, and the valve closing performance can be improved.

[0060] Further, by arranging the urging spring 9 outside the cylindrical portion 411, the urging spring 9 can be made large in diameter as compared with a structure in which the urging spring 9 is arranged inside the cylindrical portion 411. Thus, deformation other than the axis direction can be suppressed in the urging spring 9, and the valve closing performance can be improved.

[0061] Further, the urging spring 9 applies a force in the valve closing direction to the flange portion 45 in the main valve spool 4, so that the urging spring 9 can directly apply a force to the main valve spool 4, and the force can be easily transmitted, and the valve closing performance can be improved.

[0062] Further, the present application is not limited to the above-described embodiments, and includes other structures and the like that can achieve the object of the present application, and the following modifications and the like are also included in the present application. For example, in the above-described embodiments, the urging spring 9 is arranged outside the cylindrical portion 411 in a manner of following the outer peripheral surface 411B of the cylindrical portion 411, but the urging spring 9 can be arranged inside the cylindrical portion 411 in a manner of following the inner peripheral surface 411C of the cylindrical portion 411 as in the modification shown in Figure 4

[0063] In the modification shown in Figure 4 , a circular recess 414 is formed in a region outside the inner cylindrical portion 42 in the upper surface of the bottom portion 412, and the lower end portion of the urging spring 9 is arranged in the recess 414. A spring receiving member 100 is provided on the lower side of the guide boss portion 53 of the sub valve spool 5. The spring receiving member 100 is, for example, a gasket having a through hole in the substantially center, and is formed of a sliding member such as a fluororesin. The central portion of the spring receiving member 100 is protruded downward more than the outer peripheral portion, and a step portion 101 is formed between the outer peripheral portion and the central portion, and the upper end portion of the urging spring 9 abuts on the lower surface of the step portion 101. In this modification, the urging spring 9 is arranged between the sub valve spool 5 and the main valve spool 4 in a compressed state from the natural state, and applies a force in the valve closing direction to the main valve spool 4. Further, the urging spring 9 is arranged at a position that covers the communication passage 411A from the inside.

[0064] ​The spring receiving member 100 is formed of a sliding member, whereby the sliding resistance between the spring receiving member 100 and the sub valve element 5 is reduced, and a structure in which the spring receiving member 100 easily rotates with respect to the sub valve element 5 is obtained. Therefore, in the case where the sub valve element 5 rotates with the rotation of the magnetic rotor 62, the rotation force is difficult to be transmitted to the spring receiving member 100, and a force to apply a twist to the biasing spring 9 is not easily applied. In addition, even if at least the upper surface (sliding surface with respect to the sub valve element 5) of the spring receiving member is formed of a sliding member, the same effect can be expected. In addition, in the case where the friction force between the biasing spring and the sub valve element is not easily generated, a structure in which the biasing spring and the sub valve element are directly contacted without providing the divided spring receiving member can be provided.

[0065] In Figure 4 In the modification example shown in FIG. 9, the outer peripheral surface of the main valve element 4 and the guide member 3 has the same shape as that of the above embodiment, but such a shape can not be adopted. In addition, in the modification example shown in FIG. 9, the muffling member is not provided in the sub valve chamber 4R, but for example, the muffling member can be provided inside the biasing spring 9. In addition, the gap between the inner peripheral surface 411C of the cylindrical portion 411 and the outer peripheral surface of the biasing spring 9 is equal to or smaller than the inner diameter D of the communication passage 411A. Figure 4

[0066] In the above embodiment, the flow rate is reduced by the biasing spring 9 on the upstream side of the communication passage 411A, but in the modification example shown in FIG. 10, the flow rate is reduced by the biasing spring 9 on the downstream side of the communication passage 411A. Thereby, in this modification example, the noise when the fluid passes through the sub valve port 42a can be reduced. Figure 4

[0067] In addition, in the above embodiment, the gap between the outer peripheral surface 411B of the cylindrical portion 411 and the inner peripheral surface of the biasing spring 9 is equal to or smaller than the inner diameter D of the communication passage 411A, and the coil gap C of the biasing spring 9 when the main valve element 4 is seated on the main valve seat 23 is smaller than the inner diameter D of the communication passage 411A, but the relationship of these dimensions is not limited to the above relationship. For example, in the case where the biasing spring and the cylindrical portion are difficult to access, or in the case where the effective diameter of the communication passage is small, the gap between the outer peripheral surface or the inner peripheral surface of the cylindrical portion and the biasing spring can be larger than the effective diameter of the communication passage. In addition, for example, in the case where the effective diameter of the communication passage is small, the coil gap can be equal to or larger than the effective diameter of the communication passage.

[0068] In addition, in the above embodiment, the cylindrical portion 411 is slidably arranged in the guide hole 32a, but the main valve element can be guided by a portion other than the cylindrical portion, or the main valve element can not be guided in the case where the operation of the main valve element is stable.

[0069] ​​In addition, in the above-described embodiment, the urging spring 9 is disposed outside the cylindrical portion 411 to apply a force in the valve-closing direction to the flange portion 45 of the main valve spool 4, but the configuration of the portion of the main valve spool to which the urging spring applies a force is not limited thereto. For example, in the configuration in which the urging spring is disposed outside the cylindrical portion, the end portion of the urging spring can be disposed in a recess formed in the upper surface of the main valve spool, as in the modification of the above-described embodiment. According to such a configuration, the urging spring can be prevented from falling off. Figure 4

[0070] In addition, in the above-described embodiment, the sound-damping members 7 and 8 are provided, but only one of the sound-damping members can be provided, or the sound-damping members can not be provided.

[0071] The above-described embodiments of the present application have been described in detail with reference to the drawings, but the specific configuration is not limited to these embodiments, and design modifications and the like within the scope of the gist of the present application are also included in the present application.​

Claims

1. An electric valve comprising: a valve body that constitutes a main valve chamber and a main valve port; a main valve spool that adjusts an opening area between the main valve port and a main valve seat; and a sub valve spool that is disposed so as to be movable in an axial direction in a sub valve chamber formed in the main valve spool, and adjusts an opening area between a sub valve seat of a sub valve port provided to the main valve spool, the electric valve characterized in that: the main valve spool has a cylinder portion that is formed with a communication passage that communicates the main valve chamber and the sub valve chamber, a biasing spring that biases the main valve spool in a valve closing direction is disposed at a position along an inner peripheral surface or an outer peripheral surface of the cylinder portion and covers the communication passage, if the main valve spool is unseated from the main valve seat, a coil gap of the biasing spring is compressed and becomes smaller, the sub valve spool has a needle portion that adjusts the opening area with the sub valve seat, and when the needle portion is closest to the sub valve seat, the spring that biases the main valve spool in the valve closing direction is only the biasing spring.

2. The electric valve according to claim 1, characterized in that: a gap between the outer peripheral surface of the cylinder portion and an inner peripheral surface of the biasing spring, or a gap between an inner peripheral surface of the cylinder portion and an outer peripheral surface of the biasing spring is smaller than an effective diameter of the communication passage.

3. The electric valve according to claim 1 or 2, characterized in that: a coil gap of the biasing spring when the main valve spool is seated on the main valve seat is smaller than the effective diameter of the communication passage.

4. The electric valve according to claim 1 or 2, characterized in that: a guide member is provided, the guide member has a guide hole that is disposed coaxially with the main valve port and guides the main valve spool, and the cylinder portion is slidably disposed in the guide hole.

5. The electric valve according to claim 1 or 2, characterized in that: the biasing spring is disposed outside the cylinder portion.

6. The electric valve according to claim 5, characterized in that: the main valve spool has a flange portion that expands in diameter on the main valve seat side, and the biasing spring imparts a force in the valve closing direction to the flange portion. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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