JP6322562B2 - Motorized valve - Google Patents

Description

  The present invention relates to a motor-operated valve having a pilot valve body for moving a main valve body directly.

  Conventionally, as this type of electric valve, a back chamber facing the main valve body from the back side is provided, and one end opening of a pressure release passage penetrating the main valve body is disposed on the back surface of the main valve body as a pilot valve port. A system is known in which the pilot valve port is opened and closed by a pilot valve body to directly move the main valve body (see, for example, Patent Document 1).

JP 2012-154360 A (paragraphs [0025], [0026] and FIG. 1)

  However, in the conventional motor-operated valve structure, the pilot valve port moves together with the main valve body. Therefore, the linear motion stroke required for the pilot valve body that opens and closes the pilot valve port becomes longer, and the drive source increases accordingly. There was a problem.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a motor-operated valve capable of making the drive source smaller than the conventional one.

The invention of claim 1 made to achieve the above object is arranged on the downstream side of the base member (11S) having the bent flow path (16) and the bent portion (16A) of the flow path (16). A main valve port (13), a main valve body (20) addressed to the main valve port (13) from the upstream side, and the base member (11S). A support recess (17) movably fitted to the base member (11S), and a back chamber (18) on the main valve body (20) side and the opposite side are provided in the support recess (17). A partition wall (30) partitioned into a pilot room (36V) and a communication passage (30B) formed in the partition wall (30) and communicating between the back room (18) and the pilot room (36V) ) And the main valve port of the flow path (16) 13) An orifice (50) for taking the internal pressure upstream of the rear chamber (18), a valve body through hole (24) penetrating the main valve body (20) in the linear motion direction, and the partition wall (30) projecting from the valve body through-hole (24) and passing through the fixed cylinder (31) and the fixed cylinder (31), the main valve port ( 13) A cylindrical through hole (33) that communicates the downstream side of the pilot room (36V) with the pilot room (36V), and is accommodated in the pilot room (36V). A pilot valve body (42) for opening and closing the pilot valve port (33A), which is an opening, a drive source (40 V) for driving the pilot valve body (42), and the main valve body (20) on the valve closing side and an elastic member (26) for urging the front When the pilot valve (42) closes the cylindrical through-hole (33), the back room (18) the internal pressure and the elastic force and by the main valve body of the elastic member (26) (20) closing the side of The valve closing force that pushes the main valve port outweighs the valve opening force that pushes the main valve body (20) toward the valve opening side by the internal pressure of the flow path (16) upstream from the main valve port (13). While (13) is closed, when the pilot valve body (42) opens the tube through hole (33) , the valve opening force overcomes the valve closing force and the main valve port (13) is opened. In the valve (10), a fluid having a minute flow rate is formed in the pilot valve body (42) and has a minute flow rate compared with the fluid passing through the orifice (50) in a state where the main valve port (13) is closed. From the room (36V) through the tube through hole (33) A communication passage for allowing the flow to the downstream side of the in-valve port (13) (55A, 55B) electrically operated valve comprising a (10V).

In the motor operated valve (10V) of the present invention, a pilot valve port (33A) that is opened and closed by a pilot valve body (42) in a part of a cylinder through hole (33) that penetrates the fixed cylinder (31 ) of the base member (11S). Compared to the conventional one in which the pilot valve port (33A) is provided in the main valve body (20), the linear motion stroke required for the pilot valve body (42) is shortened, and the drive source (40, 40 V) can be reduced, and the cost of the drive source ( 40 V) can be reduced and the power consumption can be reduced. Further, main valve body (20) which is formed in the valve body through hole (24), the inside of the cylinder through the fixed cylinder of the base member (11S) to be fitted to the valve body through hole (24) (31) since the passage for releasing pressure from the hole (33), etc. (24R) is configured, the pilots valve port (33A) and the pilot valve body (42) on the extension of the linear motion direction of the main valve body (20) The motor-operated valve (10V) can be made to have a slim structure.

Further, according to the present invention, not only as part of the flow path (24R) valve body through hole (24) releases the pressure, the small flow rate of the fluid when the valve is closed the main valve port (13) Main It is also used as a flow path for flowing from the upstream side to the downstream side flow path (16) of the valve port (13), and has two-stage flow characteristics (small flow rate at the valve body through hole (24), and at the main valve port (13). (Large flow rate) can be used effectively.

The sectional side view of the valve-open state of the motor operated valve concerning a 1st embodiment of the present invention. Side sectional view of the motorized valve when the pilot valve port is closed Side sectional view of the motorized valve with the pilot valve closed and the main valve closed Side sectional view of the motorized valve at the moment when the pilot valve port is opened Side sectional view of the closed state of the electric valve of the second embodiment Side sectional view of the open state of the motorized valve Side sectional view of the motor operated valve of the third embodiment

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1, the motor-operated valve 10 of this embodiment is configured by assembling a drive source unit 40 to a valve body 11 that houses a main valve body 20.

  The valve body 11 has, for example, a rectangular parallelepiped shape and includes a center hole 12 extending from the center of the upper surface to a position near the lower end, and the inner diameter of the position near the lower end of the center hole 12 is reduced to form the main valve port 13 according to the present invention. ing. In addition, a first horizontal hole 14 drilled from one side surface of the valve body 11 is communicated with a position near the upper side of the main valve port 13 in the center hole 12, and a valve body is connected to a lower end portion of the center hole 12. The 2nd horizontal hole 15 drilled from the other side surface of 11 is connected. A flow path 16 bent in a crank shape is formed from the first and second lateral holes 14 and 15 and a part of the center hole 12. In the present embodiment, the upper bent portion 16A of the two bent portions having a crank shape in the flow channel 16 corresponds to the “bent portion of the flow channel” according to the present invention.

  A drive source base 30 that is a component of the drive source unit 40 is fitted and fixed to the upper end portion of the center hole 12. A base member 11S according to the present invention is constituted by the valve body 11, the drive source base 30, and a cylindrical case 35 of the drive source unit 40 described later.

  An O-ring groove 30A is formed on the outer peripheral surface of the drive source base 30, and the space between the outer peripheral surface of the drive source base 30 and the inner peripheral surface of the center hole 12 is sealed by an O-ring 30L attached thereto. Yes. Further, the lower end surface of the drive source base 30 is located above the portion of the center hole 12 that communicates with the first lateral hole 14, so that the middle portion of the center hole 12 can bend the bent portion 16 </ b> A of the flow path 16. The support recess 17 according to the present invention is opposed to the main valve port 13 with being sandwiched therebetween. The main valve body 20 is fitted in the support recess 17 so as to be linearly movable, and the back chamber 18 according to the present invention is formed between the main valve body 20 and the drive source base 30. A ring-shaped spacer 18 </ b> S for securing the back chamber 18 is fitted and fixed between the main valve body 20 and the drive source base 30 on the upper end side (back side) of the support recess 17. Instead of the spacer 18S, a recess may be provided in the upper end portion of the main valve body 20 to secure the space of the back room 18.

  The outer peripheral surface of the main valve body 20 is a large-diameter portion 20A, a small-diameter portion 20B, and a tapered portion 20C in order from the upper end side, and the large-diameter portion 20A is supported by the support recess 17 so as to be capable of linear movement. Further, a sliding ring groove 20D is formed in the large diameter portion 20A, and, for example, a resin sliding ring 23 is attached thereto. The gap between the large diameter portion 20A of the main valve body 20, the inner peripheral surface of the center hole 12, the sliding ring 23 and the spacer 18S is the orifice 20S according to the present invention.

  The small-diameter portion 20B of the main valve body 20 is stepped smaller than the large-diameter portion 20A, and a tapered portion 20C is formed so that the diameter is gradually reduced from the lower end of the small-diameter portion 20B. Further, the lower end portion of the tapered portion 20 </ b> C is smaller than the inner diameter of the main valve port 13. On the other hand, from the opening edge of the main valve port 13, a valve port protruding wall 13T protrudes toward the main valve body 20, and the inner edge portion of the upper end of the valve port protruding wall 13T is a valve seat 13Z. As shown in FIG. 3, the main valve body 20 has a valve closing position in which the taper portion 20C abuts the valve seat 13Z and closes the main valve port 13, and the taper portion 20C is valved as shown in FIG. It moves away from the seat 13Z and linearly moves between the valve opening position where the rear end portion is in contact with the spacer 18S.

  A valve body through hole 24 according to the present invention is formed at the center of the main valve body 20. In addition, a communication channel 25 that extends in the radial direction of the main valve body 20 and opens on the side surface of the small diameter portion 20 </ b> B communicates with a position near the lower end of the valve body through hole 24. A seal member 20E projects from a position near the upper end of the inner peripheral surface of the valve body through hole 24. Specifically, the main valve body 20 is divided into first and second valve body constituting portions 21 and 22 in the axial direction. Further, a sheet-like seal member 20 </ b> E is sandwiched between the split surfaces of the first and second valve body components 21, 22 and protrudes into the valve body through hole 24.

  A central recess 32 is formed in the center of the driving source base 30 facing the main valve body 20, and a fixed cylinder 31 is extended from the inner part of the central recess 32 and fitted into the valve body through hole 24. ing. Regardless of the linear movement position of the main valve body 20, the fixed cylinder 31 has a length in which the front end surface of the fixed cylinder 31 is disposed between the seal member 20 </ b> E and the communication flow path 25 in the valve body through hole 24. Yes. Further, on the upper surface of the main valve body 20, a spring receiving portion 20 </ b> F is formed by expanding the upper end portion of the valve body through hole 24 in a stepped shape, and the compression coil spring 26 (the book) inserted through the outside of the fixed cylinder 31. (Corresponding to the “elastic member” of the present invention) is stretched between the back surface of the central recess 32 and the step surface of the spring receiving portion 20F to urge the main valve body 20 to the valve closing position. .

  A cylindrical pedestal 34 projects from the center of the upper surface of the drive source base 30. Further, the outer diameter of the upper end portion of the pedestal portion 34 is reduced in a stepped shape, and the lower end portion of the cylindrical case 35 with the upper end bottom and the lower end open is fitted and welded thereto. In addition, a coil 37 is fitted to the outside of the cylindrical case 35, and a plunger 38 is accommodated in the cylindrical case 35 so as to be linearly movable.

  The lower end portion of the plunger 38 is a cylindrical portion 39 that has a diameter reduced to a stepped shape. Then, the compression coil spring 41 is fitted to the outside of the cylindrical portion 39, and is stretched between the step surface on the rear end side of the cylindrical portion 39 and the end surface of the pedestal portion 34, and the plunger 38 is moved from the drive source base 30. It is energizing to the side to separate.

  In the present embodiment, the above-described compression coil spring 41, plunger 38, coil 37, cylindrical case 35, and drive source base 30 constitute a drive source unit 40 that corresponds to the “drive source” of the present invention. The inside of the cylindrical case 35 of the drive source unit 40 is a pilot room 36 according to the present invention, and the back room 18 and the pilot room are driven by the drive source base 30 corresponding to the “partition wall” according to the present invention. 36 is partitioned. A cylinder through hole 33 according to the present invention passes through the drive source base 30 and the fixed cylinder 31. A plurality of communication passages 30B are formed around the tube through-hole 33, and the back room 18 and the pilot room 36 are communicated with each other through the communication passages 30B. The communication passage 30B, the pilot chamber 36, the cylinder through hole 33, and the valve body through hole 24 constitute a pressure release flow path 24R according to the present invention.

  The opening on the pilot chamber 36 side in the tube through-hole 33 forms a pilot valve port 33A according to the present invention, and an inner edge portion of the pilot valve port 33A is a valve seat 33Z. On the other hand, a conical pilot valve body 42 protrudes from the center of the front end surface of the plunger 38. When the coil 37 is energized, the plunger 38 moves to the drive source base 30 side against the compression coil spring 41, the tapered surface of the pilot valve body 42 contacts the valve seat 33Z, and the pilot valve port 33A is closed. The

  This completes the description of the structure of the motor-operated valve 10 of the present embodiment. Next, the function and effect of the motor-operated valve 10 will be described. In the motor-operated valve 10, when the coil 37 is not energized, as shown in FIG. It becomes lower than the internal pressure of the bent portion 16A of the channel 16 on the more upstream side. As a result, the valve opening force that pushes the main valve body 20 toward the valve opening side by the fluid pressure applied to the step surface between the small diameter portion 20B and the large diameter portion 20A and the taper portion 20C of the main valve body 20 is The valve closing force that pushes the main valve element 20 toward the valve closing side is overcome by the internal pressure of 18 and the elastic force of the compression coil spring 26, and the main valve element 20 is held in the valve-opened state away from the valve seat 13 </ b> Z of the main valve port 13. Is done.

  When the coil 37 is energized in this state, as shown in FIG. 2, the plunger 38 moves forward toward the drive source base 30 against the elastic force of the compression coil spring 41, and the pilot valve element 42 closes the pilot valve port 33A. I speak. Then, the fluid pressure upstream of the main valve port 13 is taken into the back chamber 18 through the orifice 20S on the outer periphery of the main valve body 20, and the above-described valve closing force overcomes the valve opening force, as shown in FIG. The main valve body 20 is brought into contact with the valve seat 13Z of the main valve port 13 to be closed. In the state where the main valve port 13 is closed, the fluid in the flow channel 16 upstream from the main valve port 13 through a part of the communication flow channel 25 and the valve body through-hole 24 flows into the downstream flow channel 16. It flows slightly.

  When the energization of the coil 37 is stopped while the main valve port 13 is closed, the pilot valve body 42 is retracted together with the plunger 38 by the elastic force of the compression coil spring 41, and the pilot valve port 33A is opened. Then, the internal pressure in the back chamber 18 is released to the flow path 16 on the downstream side of the main valve port 13, and the valve opening force against the main valve body 20 is again superior to the valve closing force, as shown in FIG. In addition, the main valve body 20 is separated from the valve seat 13Z and the main valve port 13 is opened.

  As described above, in the motor-operated valve 10, the pilot valve body 42 is driven to open and close the pilot valve port 33A, thereby changing the internal pressure of the back chamber 18 on the back side of the main valve body 20, so that the diameter of the pilot valve port 33A is larger. The large main valve port 13 can be opened and closed. In the motor-operated valve 10 according to the present embodiment, the pilot valve port 33A is provided in the base member 11S, so that it is necessary for the pilot valve body 42 as compared with the conventional valve valve 33A provided in the main valve body 20. Linear motion stroke is shortened. As a result, the drive source unit 40 can be reduced in size, and the cost of the drive source unit 40 can be reduced and the power consumption can be reduced.

  In addition, a structure in which the entire pressure release flow path 24R is formed in the base member 11S is conceivable, but in the electric valve 10 of the present embodiment, a part of the pressure release flow path 24R is formed by the valve body through hole 24 of the main valve body 20. The base member 11S is fitted with the fixed cylinder 31 of the base member 11S in the valve body through hole 24, and the pilot valve port 33A at one end of the cylinder through hole 33 in the fixed cylinder 31 is disposed in the base member 11S. The pilot valve port 33A and the pilot valve body 42 can be disposed on the extension of the valve body 20 in the linear motion direction, and the motor-operated valve 10 can have a slim structure. Further, the valve body through-hole 24 is used as a flow path for flowing a small flow rate of fluid when the main valve port 13 is closed, so that effective use is achieved.

[Second Embodiment]
The motor-operated valve 10V of this embodiment is shown in FIGS. 5 and 6, and the motor-operated valve 10 of the above-described embodiment is a so-called normal open type in which the main valve port 13 is opened when not energized. On the other hand, the motor-operated valve 10V of the present embodiment is a so-called normally closed type in which the main valve port 13 is closed when no power is supplied. Specifically, the drive source unit 40V of the electric valve 10V includes a cylindrical yoke 53 fitted to the upper end of the cylindrical case 52, and a coil 57 is provided outside the cylindrical case 52 and the yoke 53. The plunger 54 is accommodated inside the cylindrical case 52 so as to be linearly movable.

  In addition, a pilot chamber 36V is formed in a recessed manner on the upper surface of the drive source base 30, and the lower end portion of the cylindrical case 52 is fitted to a case fitting portion 30N whose inner side surface of the pilot chamber 36V has a stepped diameter. It is fixed. Further, the plunger 54 has a spring accommodating recess 54A formed on the upper surface, and the plunger 54 is urged downward by a compression coil spring 56 accommodated therein. A conical pilot valve body 42 is provided at the tip of the cylindrical portion 55 that protrudes downward from the plunger 54. A first communication channel 55A penetrating in the radial direction is formed at the lower end of the cylindrical portion 55, and a second communication channel 55B extends from the first communication channel 55A to the tip of the pilot valve body 42. The “communication flow path” according to the present invention is constituted by the first and second communication flow paths 55A and 55B.

  The main valve body 20 </ b> V is formed with a cylindrical recess 18 </ b> V that surrounds the valve body through hole 24 and is open to the drive source base 30 side, and the cylindrical recess 18 </ b> V forms a part of the back chamber 18. The cylindrical recess 18V accommodates a compression coil spring 26 that urges the main valve body 20V toward the valve closing side. Further, the main valve body 20V communicates between the outer surface and the cylindrical recess 18V. Thus, the orifice 50 is formed. About another structure, it is the same as that of the motor operated valve 10 of 1st Embodiment.

  In the motor operated valve 10V of the present embodiment, the pilot valve port 33A is closed by the pilot valve body 42 as shown in FIG. As a result, the internal pressure of the bent portion 16A of the flow path 16 upstream of the main valve port 13 is taken into the back chamber 18 side through the orifice 50, and the valve closing force for the main valve body 20V overcomes the valve opening force. The valve body 20V closes the main valve port 13. In this state, a small amount of fluid in the back chamber 18 passes through the back chamber 18, the communication passage 30 </ b> B, the first and second communication channels 55 </ b> A and 55 </ b> B, the valve body through-hole 24, and the like. It flows to the flow path 16 on the downstream side from the port 13.

  On the other hand, when the coil 57 is energized, as shown in FIG. 6, the pilot valve body 42 moves to the yoke 53 side together with the plunger 54, and the pilot valve port 33A opens. Then, the internal pressure in the back chamber 18 is released to the downstream side of the main valve port 13, the valve opening force with respect to the main valve body 20V overcomes the valve closing force, and the main valve body 20V is separated from the valve seat 13Z. Opens.

  As described above, the motor-operated valve 10V of the present embodiment also changes the internal pressure of the back chamber 18 on the back side of the main valve body 20V by driving the pilot valve body 42 to open and close the pilot valve port 33A. The main valve port 13 having a larger diameter than the valve port 33A can be opened and closed. And in the motor operated valve 10V of this embodiment, while the cylindrical recessed part 18V formed so that the valve body through-hole 24 may be enclosed among main valve bodies 20V comprises a part of back room 18, the main valve body 20V is changed. Since it also serves as a housing portion for the compression coil spring 26 that urges toward the valve closing side, the motor-operated valve 10V becomes compact in the direct acting direction of the main valve body 20V. Further, since the orifice 50 penetrates the cylindrical recess 18V from the outer surface of the main valve body 20V, the pressure can be stably taken into the back chamber 18 through the orifice 50.

[Third Embodiment]
The electric valve 10W of the present embodiment is shown in FIG. 7, and is different from the electric valve 10V of the second embodiment in the configuration of the drive source unit 40W and is a stepping motor. That is, the cylindrical case 35W fixed to the case fitting portion 30N of the drive source base 30 is formed by closing the upper end portion of the thin cylindrical tube 35A with the upper lid member 35B. A ring-shaped field winding unit 46 is fitted to the outside of the cylindrical case 35W, while a rotor 49 is rotatably accommodated inside the cylindrical case 35W. A stepping motor having the unit 46 and the rotor 49 as main parts is configured. The field winding unit 46 can be connected to the controller via a connector.

  Further, in order to rotatably support the rotor 49, the lower end portion of the cylindrical case 35W is bent at a right angle to the inside to form a pedestal portion 35F, which is fixed to the pedestal portion 35F and rises upward. A support sleeve 43 is fixed to the inner side of the cover. On the other hand, the rotor 49 has a structure in which the rod portion 44 is fixed in a penetrating state at the upper center of the cylindrical field portion 45 having an upper end bottom and an open lower end. The upper end portion of the rod portion 44 located in the cylindrical field portion 45 is supported by the upper end portion in the support sleeve 43 so as to be linearly movable and rotatable, and on the lower end portion of the rod portion 44. The formed male screw portion 44 </ b> B is screwed into a female screw portion 43 </ b> N formed at the lower end portion of the support sleeve 43. Further, the cylindrical field part 45 is adjacent to the inner surface of the cylindrical case 35W in a state where the support sleeve 43 is covered from the outside. Then, the rotor 49 moves up and down while being rotationally driven by the magnetic force between the field winding unit 46 and the cylindrical field part 45.

  In addition, a spiral guide 46G in which a wire rod is spirally wound is provided in a portion of the rod portion 44 above the cylindrical field portion 45, and an arm portion 47A of a stopper ring 47 engaged with the spiral guide 46G. Is in contact with a stopper shaft 48 suspended from the upper lid member 35B of the cylindrical case 35W. When the rotor 49 rotates, the stopper ring 47 rotates relative to the spiral guide 46G and moves up and down, and when the rotor ring 49 moves to the upper end portion or the lower end portion of the spiral guide 46G, the rotation becomes impossible. To regulate.

  Further, the lower end portion of the rod portion 44 is a cylindrical portion 44C having an open lower end. The compression coil spring 51 is accommodated in the cylindrical portion 44C, and the upper end portion of the linear motion shaft 42S is accommodated in the lower portion thereof so as to be linearly movable. ing. Further, a flange 42F provided at the upper end of the linear movement shaft 42S is in contact with the bush 44T fitted and fixed to the lower end of the cylindrical portion 44C from above, and is prevented from coming off in the cylindrical portion 44C. Thereby, the linear motion shaft 42 </ b> S moves up and down together with the rotor 49. The lower end portion of the linear motion shaft 42S is tapered to form a pilot valve body 42, and the tapered surface 42T enters the pilot valve port 33A.

  According to the electric valve 10W of this embodiment, the position of the pilot valve body 42 is controlled by the drive source unit 40W to gradually change the opening degree of the pilot valve port 33A, and the pressure is released when the main valve port 13 is closed. It becomes possible to control the flow rate of the fluid flowing from the upstream side to the downstream side of the main valve port 13 through the flow path 24R. Specifically, an arbitrary flow rate control can be performed within a small flow rate range equal to or smaller than the inner diameter of the orifice 50, and a large flow rate can be obtained by the main valve body 20V opening the main valve port 13 at a flow rate larger than the inner diameter of the orifice 50. Effective use is planned.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, and can be implemented with various modifications other than those described above without departing from the scope of the invention.

10, 10V, 10W Motorized valve 11S Base member 13 Main valve port 16 Flow path 16A Bending portion 17 Supporting concave portion 18 Back chamber 18V Cylindrical concave portion 20 Main valve body 20S, 50 Orifice 20V Main valve body 24 Valve body through hole 24R Pressure release Flow path 26 Compression coil spring (elastic member)
30 Drive source base (partition wall)
30B Communication path 31 Fixed cylinder 33 Tube through hole 33A Pilot valve port 36, 36V Pilot room 37 Coil 40, 40V, 40W Drive source unit (drive source)
41 Compression coil spring 42 Pilot valve body 42T Taper surface 55A, 55B Communication flow path

Claims (1)

A base member (11S) having a bent channel (16) ;
A main valve port (13) disposed on the downstream side of the bent portion (16A) of the flow path (16);
A main valve body (20) addressed to the main valve port (13) from the upstream side;
A support recess (17) provided on the base member (11S) and fitted with the main valve body (20) so as to be linearly movable;
A partition wall (provided in the base member (11S)) that divides the inside of the support recess (17) into a back chamber (18) on the main valve body (20) side and a pilot chamber (36V) on the opposite side. 30),
A communication path (30B) formed in the partition wall (30) and communicating between the back room (18) and the pilot room (36V);
An orifice (50) for taking the internal pressure upstream of the main valve port (13) in the flow path (16) into the back chamber (18);
A valve body through hole (24) penetrating the main valve body (20) in the linear motion direction;
A fixed cylinder (31) protruding from the partition wall (30) and fitted in the valve body through hole (24);
A cylinder through-hole (33) penetrating the fixed cylinder (31) and connecting the pilot chamber (36V) downstream of the main valve port (13) in the flow path (16);
A pilot valve body (42) housed in the pilot chamber (36V) and opening and closing a pilot valve port (33A) which is an opening of the pilot chamber (36V) in the cylindrical through hole (33);
A drive source ( 40V) for driving the pilot valve body (42);
An elastic member (26) for biasing the main valve body (20) toward the valve closing side,
When the pilot valve body (42) closes the cylindrical through hole (33) , the main valve body (20) is closed by the internal pressure of the back chamber (18) and the elastic force of the elastic member (26). The valve closing force that pushes the valve to the side overcomes the valve opening force that pushes the main valve element (20) to the valve opening side by the internal pressure of the flow path (16) upstream from the main valve port (13). When the port (13) is closed, when the pilot valve body (42) opens the tube through hole (33) , the valve opening force overcomes the valve closing force and the main valve port (13) is opened. In the motor-operated valve (10),
A fluid having a minute flow rate from the pilot chamber (36V) is formed in the pilot valve body (42) and has a small flow rate compared to the fluid passing through the orifice (50) with the main valve port (13) closed. A motor-operated valve (10V) provided with a communication flow path (55A, 55B) allowing flow through the tube through hole (33) to the downstream side of the main valve port (13).

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