CN220227844U

CN220227844U - Electric valve

Info

Publication number: CN220227844U
Application number: CN202321609829.2U
Authority: CN
Inventors: 矢泽将志; 菅沼威
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2022-08-24
Filing date: 2023-06-25
Publication date: 2023-12-22
Anticipated expiration: 2033-06-25
Also published as: JP2024030475A

Abstract

Provided is an electrically operated valve which can save energy without increasing the weight and can suppress noise. The electric valve includes: a valve shaft that is driven to rotate by a motor and that moves in an axial direction; a valve body which is provided with a valve seat and a guide member in a valve chamber and which holds the valve shaft rotatably; and a valve element unit connected to the valve shaft, the valve element unit having: a sleeve slidable along an axial direction of the valve body with respect to the hollow cylindrical portion of the guide member; and a seat member coupled to the sleeve and seated on or separated from the valve seat, wherein the seat member abuts against the guide member when the seat member is separated from the valve seat by a maximum distance.

Description

Electric valve

Technical Field

The present utility model relates to an electrically operated valve.

Background

For example, a motor-driven electric valve includes a screw mechanism in which an external screw portion of a valve shaft driven to rotate by a stepping motor is screwed into an internal screw hole provided in a valve body. By this screw mechanism, the valve shaft is displaced in the axial direction while rotating around the axis, and the gap between the valve body and the valve seat is increased or decreased to control the flow rate.

In the electric valve disclosed in patent document 1, a seat member that is capable of relative movement with respect to a hollow cylindrical retainer fixed to a valve body is disposed, and the seat member is coupled to a valve shaft and is attached to a lower end of a sleeve that is capable of sliding with respect to the retainer. The valve shaft is lifted and lowered, and a tapered seat surface formed on the seat member is seated on the valve seat to be in a valve-closed state, or the seat surface is separated from the valve seat to be in a valve-open state.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 2021-110450

Technical problem to be solved by the utility model

According to the electric valve of patent document 1, in the valve-opened state, the refrigerant that has entered the valve chamber from the supply-side round tube flows into the discharge-side round tube through the gap between the seat surface and the valve seat. In this case, since the seat member is supported in a cantilever manner at the lower end of the sleeve and is disposed at a position facing the supply-side round tube, the refrigerant flowing in from the supply-side round tube may directly contact the seat member, and vibration of the seat member may be caused, thereby generating noise. In order to suppress the vibration of the seat member, there is a problem that the rigidity of each portion is increased or the gap between the sleeve and the holder is reduced, but the increase in the rigidity of each portion causes an increase in weight, and when the gap between the sleeve and the holder is reduced, the sliding resistance increases, so that a large force is required to drive the valve shaft, and energy saving cannot be achieved.

Disclosure of Invention

Accordingly, an object of the present utility model is to provide an electrically operated valve that can save energy without increasing the weight and suppress noise.

Technical means for solving the technical problems

The electric valve of the present utility model comprises:

a valve shaft that is driven to rotate by a motor and that moves in an axial direction;

a valve body that includes a valve seat and a guide member in a valve chamber and that rotatably holds the valve shaft; and

a valve core unit connected with the valve shaft,

the valve body unit includes a sleeve slidable along an axial direction of the valve body with respect to a hollow cylinder portion of the guide member, and a seat member coupled to the sleeve and seated on or unseated from the valve seat,

the seat member abuts the guide member when the seat member is separated from the valve seat by a maximum distance.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present utility model, it is possible to provide an electrically operated valve that can save energy without increasing the weight and suppress noise.

Drawings

Fig. 1 is a longitudinal sectional view of an electric valve according to the present embodiment in a closed valve state.

Fig. 2 is a longitudinal sectional view showing the motor-operated valve according to the present embodiment in an intermediate state.

Fig. 3 is a longitudinal sectional view of the motor-operated valve according to the present embodiment in the valve-opened state.

Fig. 4 is an enlarged longitudinal sectional view showing the vicinity of the valve element unit of the expansion valve in the intermediate state.

Symbol description

1. An electric valve;

10. a valve body;

11. a valve seat member;

11e valve seat;

15 guide rods;

15b a hollow cylinder;

15e, a first conical surface;

21. a valve shaft;

30. a rotor;

35. a movable stopper for closing the valve;

36. a movable stopper for opening the valve;

50. a stator;

53. a stator coil;

55. a fixed stopper for closing the valve;

56. a fixed stopper for the valve opening direction;

70. a valve core unit;

71. a sleeve;

71c communicating holes;

72 seat parts;

72c a seat surface;

72g of a second conical surface;

73. a gasket;

74. an upper coil spring;

76. a spring support member;

77. a lower coil spring;

a VC valve chamber;

t1 a first piping;

t2 second piping.

Detailed Description

Hereinafter, embodiments of the present utility model will be described with reference to the drawings.

Fig. 1 is a longitudinal sectional view of an electric valve according to the present embodiment in a closed valve state. Fig. 2 is a longitudinal sectional view showing the electric valve according to the present embodiment in an intermediate state between a valve-closed state and a valve-open state. Fig. 3 is a longitudinal sectional view of the motor-operated valve according to the present embodiment in the valve-opened state. Here, the upper side refers to the rotor side in the electric valve 1, and the lower side refers to the valve seat side with respect to the rotor.

(Structure of electric valve)

The electric valve 1 includes: a valve body 10 having a bottomed cylindrical shape and an upper end opening; a top cylindrical case 45, a lower end portion of the case 45 being sealingly joined to an upper end surface of the valve main body 10 by welding or the like; a guide rod (guide member) 15, the guide rod 15 being fixed to the inside of the valve main body 10; a valve shaft 21, the valve shaft 21 being disposed inside the guide rod 15; a rotor 30, the rotor 30 being integrally rotatably coupled to the valve shaft 21; and a stator 50, wherein the stator 50 is externally embedded on the outer circumference of the housing 45 to drive the rotor 30 to rotate. Here, the rotor 30 and the stator 50 constitute a stepping motor. The axis of the motor-operated valve 1 is L.

The valve body 10 is formed by connecting a hollow cylindrical portion 10a and a bottom wall portion 10 b. The hollow cylindrical portion 10a and the bottom wall portion 10b have substantially the same wall thickness.

A circular opening 10d is formed in the center of the bottom wall portion 10b, and the valve seat member 11 is fixed to the opening 10d by brazing or the like. The valve seat member 11 is formed by connecting a hollow reduced diameter cylindrical portion 11a and an expanded diameter cylindrical portion 11b in the direction of the axis L, and the reduced diameter cylindrical portion 11a has a wall thickness smaller than that of the expanded diameter cylindrical portion 11 b. The reduced diameter cylindrical portion 11a is fitted into the opening 10d. An end portion of the first pipe T1 is inserted into an annular recess 11c formed at a lower end of the expanded diameter cylindrical portion 11b, and is connected by brazing or the like.

An orifice 11d is formed in the centers of the diameter-reduced cylindrical portion 11a and the diameter-enlarged cylindrical portion 11b, and a valve seat 11e is formed at the upper end of the orifice 11d (the inner periphery of the upper end of the diameter-reduced cylindrical portion 11 a). The inner diameter of the orifice 11d is reduced at the lower end side of the valve seat 11e side. In the present embodiment, the guide rod 15 and the valve seat member 11 are fixed to and part of the valve body 10.

An inlet opening 10e is formed in the hollow cylindrical portion 10a of the valve body 10, and an end portion of the second pipe T2 is inserted into the inlet opening 10e and connected by brazing or the like. The axis of the inlet opening 10e is set to O.

The lower end of the housing 45 abuts against the upper end of the valve body 10 and is joined by welding, thereby integrating the valve body 10 and the housing 45 in a sealed state. Further, a flange-like disk 18 is disposed inside the lower end of the housing 45 at the upper end of the valve body 10. Preferably, the flange-like disc 18 is welded simultaneously when the valve body 10 is welded to the housing 45. The flange-like disk 18 is provided with a plurality of through holes, so that the refrigerant (fluid) can flow out and in between the inside of the valve body 10 and the inside of the case 45.

In fig. 1, a yoke 51, a bobbin 52, and a stator coil 53 are arranged outside a case 45 to form a stator 50, and the outer periphery of the stator 50 is covered with a resin molding cover 58. In the present embodiment, the resin mold cover 58 covers the entire stator 50 including the upper portion of the housing 45, but may cover only the periphery of the yoke 51. The rotor 30 and the stator 50 constitute a stepping motor.

The stator coil 53 is connected to an external power supply circuit (not shown) via the board CB, the connector CN, and the wiring HN. The substrate CB and the connector CN are covered with another resin cover 57. By energizing the stator coil 53, the rotor 30 disposed in the housing 45 can be rotated about the axis L. The resin cover 57 is filled with a molding resin.

The guide rod 15 disposed inside the rotor 30 is formed by connecting a solid cylindrical body 15a and a hollow cylindrical portion 15 b. The body 15a is formed with a female screw hole 15c penetrating the center thereof in the direction of the axis L. A flange-like disk 18 is fixed to the outer periphery of the hollow cylindrical portion 15b, and the guide rod 15 is fixed to the valve body 10 by welding the flange-like disk 18 to the upper end of the valve body 10 as described above. The hollow cylindrical portion 15b is formed with pressure equalizing holes 15d penetrating the inner and outer circumferences thereof. The lower end of the hollow tube portion 15b is located below (on the valve seat side) at least the inner peripheral upper end of the second pipe T2, preferably below the center of the second pipe T2. A first tapered surface 15e having a tapered shape that reduces in diameter as going upward is formed on the inner periphery of the lower end of the hollow cylindrical portion 15 b.

In order to set the control origin positions of the rotor 30 and the valve shaft 21, a valve closing direction fixing stopper 55 having a rectangular cross section is provided on the upper surface of the main body 15a of the guide rod 15 so as to protrude upward, and a valve opening direction fixing stopper 56 having a rectangular cross section is provided on the lower surface of the main body 15a of the guide rod 15 so as to protrude downward. Here, the control origin position of the rotor 30 and the valve shaft 21 is a position at which the movable stopper 35 for the valve closing direction abuts against and is locked by the fixed stopper 55 for the valve closing direction, and the rotor 30 and the valve shaft 21 reach the lowermost position.

The valve shaft 21 is formed by coaxially connecting a first cylindrical portion 21a, which is externally fitted with an annular coupling body 32 attached to the rotor 30, a male screw portion 21b, which is screwed into the female screw hole 15c of the guide rod 15, a flange-like portion 21c, which is formed below the male screw portion 21b, a second cylindrical portion 21d, which is provided so as to be continuous below the flange-like portion 21c, a third cylindrical portion 21e, which is smaller in diameter than the second cylindrical portion 21d, a fourth cylindrical portion 21f, which is smaller in diameter than the third cylindrical portion 21e, and a tapered portion 21g, which is smaller in diameter as it goes downward.

An upper end portion of the male screw portion 21b of the valve shaft 21 is screwed to the valve closing direction movable stopper 35 and engaged with the lower surface of the upper wall of the rotor 30. A stopper portion 35a having a rectangular cross section is formed on the lower surface of the movable stopper 35 for closing the valve.

The lower end of the male screw portion 21b of the valve shaft 21 is screwed into the movable stopper 36 for the valve opening direction and is locked to the upper surface of the flange-like portion 21 c. A stopper portion 36a having a rectangular cross section is formed on the upper surface of the movable stopper 36 for the valve opening direction.

The space in the valve body 10 is defined as a valve chamber VC. The valve body unit 70 is disposed in the valve chamber VC so as to be displaceable along the axis L. The valve body unit 70 connected to the valve shaft 21 includes a sleeve 71 inserted into the hollow cylindrical portion 15b of the guide rod 15, and a disk-shaped seat member 72 joined to the lower end of the sleeve 71.

Fig. 4 is an enlarged longitudinal sectional view showing the vicinity of the spool unit 70 of the expansion valve, and shows an intermediate state. In fig. 4, the sleeve 71 is formed by connecting a cylindrical side wall 71a and a partition wall 71b formed radially inward in the center of the side wall 71 a. Near the lower end of the side wall 71a, four communication holes 71c are formed at equal intervals in the circumferential direction, and a circular opening 71d is formed in the center of the partition wall 71 b.

The seat member 72 is formed by connecting a disk portion 72a and a short cylindrical portion 72b having a smaller diameter than the disk portion 72 a. A tapered seat surface 72c, which reduces in diameter as it goes downward, is formed on the outer periphery of the lower surface of the disk portion 72a, and is capable of being seated on the valve seat 11e of the valve seat member 11. A tapered second tapered surface 72g, which tapers upward, is formed on the outer periphery of the upper surface of the disk portion 72 a. The taper angles (the angles of the taper surfaces in the section through the axis L) of the first taper surface 15e and the second taper surface 72g are almost equal.

The lower end of the sleeve 71 abuts against the upper surface of the disk portion 72a, and the inner periphery of the lower end side of the sleeve 71 is press-fitted into the short cylindrical portion 72b to be fixed. However, the seat member 72 and the sleeve 71 may be fixed by welding or the like.

A through hole 72f is formed in the center of the seat member 72, the through hole being formed by connecting an upper end side cylindrical hole 72d and a lower end side tapered hole 72 e. By providing the tapered hole 72e that gradually expands in diameter while being connected to the cylindrical hole 72d, the sound of the refrigerant passing therethrough is reduced, and the motor-operated valve 1 is silenced. Here, the cylindrical hole 72d constitutes a valve port.

In the present embodiment, the outer diameter of the sleeve 71 is equal to or slightly smaller than the inner diameter of the hollow cylinder 15 b. On the other hand, the outer diameter of the disc portion 72a of the seat member 72 is larger than the inner diameter of the hollow cylindrical portion 15 b. Thus, when the seat member 72 is raised relative to the hollow cylindrical portion 15b, the first tapered surface 15e abuts against the second tapered surface 72g.

A spring holder member 76 is attached to the fourth cylindrical portion 21f of the valve shaft 21. The bottomed cylindrical spring holder member 76 is formed by connecting a peripheral wall 76a and a bottom wall 76 b. A center hole 76c is formed in the center of the bottom wall 76b, the fourth cylindrical portion 21f is fitted by press fitting, and the valve shaft 21 is lifted and lowered integrally with the spring holder member 76. A lower coil spring 77 is disposed inside the peripheral wall 76a, that is, on the bottom wall 76b and the partition wall 71 b. The lower coil spring 77 is a first spring member that biases the sleeve 71 toward the valve opening side with respect to the valve shaft 21.

An annular washer 73 is disposed below the flange-like portion 21c of the valve shaft 21, and an upper coil spring 74 is disposed inside the side wall 71a and supported by the washer 73 and the partition wall 71 b. The washer 73 is made of a material having high sliding properties, and functions to suppress rotation of the valve body unit 70 by making it difficult for torque to be transmitted to the upper coil spring 74 when the valve shaft 21 rotates. The upper coil spring 74 is a second spring member that biases the sleeve 71 toward the valve closing side with respect to the valve shaft 21.

The third cylindrical portion 21e of the valve shaft 21 is slidably inserted through the circular opening 71d of the sleeve 71.

(action of electric valve)

Next, the operation of the opening/closing valve of the electric valve will be specifically described.

First, it is assumed that the refrigerant (fluid) enters the valve chamber VC from the second pipe T2, and the electrically operated valve 1 is in the valve-closed state shown in fig. 1. In the closed valve state, the elastic force of the upper coil spring 74 compressed between the flange portion 21c and the partition wall 71b is transmitted to the seat member 72 via the sleeve 71, and the seat surface 72c is seated on the valve seat 11e. On the other hand, the upper end of the lower coil spring 77 supported by the spring holder member 76 is separated from the lower surface of the partition wall 71b, and is in a state of no elastic deformation.

At this time, the seat member 72 and a part of the sleeve 71 protrude downward from the lower end of the hollow cylindrical portion 15b of the guide rod 15 (exposed state). In a state where a part of the sleeve 71 protrudes, the communication hole 71c is also exposed from the lower end of the hollow cylindrical portion 15 b. Thereby, the inner space of the sleeve 71 communicates with the valve chamber VC, and the inner space of the sleeve 71 also communicates with the inner space of the hollow cylinder 15b via the gap between the sleeve 71 and the hollow cylinder 15b, and the like. The tapered portion 21g of the valve shaft 21 is inserted into the cylindrical hole 72d of the seat member 72 to close the cylindrical hole 72d, thereby restricting the flow of the refrigerant from the valve chamber VC toward the first pipe T1 side.

In the present embodiment, even if there is a gap between the cylindrical hole 72d and the tapered portion 21g at the lowest movement position of the valve shaft 21, a minute flow rate is ensured (this structure is referred to as a non-valve-closing structure), but it is needless to say that the tapered portion 21g may be seated on the seat member 72 so that the valve can be completely closed (this structure is referred to as a valve-closing structure).

When pulse power is supplied from an external power supply circuit to the stator 50 in this valve-closed state, the rotor 30 and the valve shaft 21 are driven to rotate in one direction, and the valve shaft 21 is rotated and raised while passing through a screw feed mechanism constituted by the female screw hole 15c and the male screw portion 21 b. However, since the elastic force of the upper coil spring 74 continues to be transmitted to the seat member 72 until the valve shaft 21 rises to a predetermined distance, the seat surface 72c is kept seated on the valve seat 11e, and the refrigerant flowing toward the orifice 11d is continuously blocked.

Since the tapered portion 21g of the valve shaft 21 is separated from the cylindrical hole 72d of the seat member 72 by the rising of the valve shaft 21, the refrigerant in the sleeve 71 passes through the gap between the valve shaft 21 and the cylindrical hole 72d, further passes through the through hole 72f and the orifice 11d of the valve seat member 11, and flows out toward the first pipe T1. Thereby, the pressure in the sleeve 71 and the hollow cylinder 15b decreases, and the valve element unit 70 easily rises.

The valve shaft 21 further rises against the elastic force of the upper coil spring 74, and the sleeve 71 and the seat member 72 start to rise from the time when the upper end of the spring holder member 76 abuts against the lower surface of the partition wall 71b of the sleeve 71. Accordingly, the refrigerant in the valve chamber VC flows through the orifice 11d to the first pipe T1 through the gap between the seat surface 72c and the valve seat 11e.

The period from when the valve shaft 21 is raised by the first distance from the valve-closed state to when the valve shaft reaches the second distance, which is not in the completely opened state, is defined as a specific intermediate state. In the specific intermediate state, as shown in fig. 2, the upper end of the lower coil spring 77 supported by the spring holder member 76 is not yet in contact with the lower surface of the partition wall 71b, and the washer 73 placed on the upper end of the upper coil spring 74 is separated from the flange-like portion 21 c. That is, the upper coil spring 74 and the lower coil spring 77 are not elastically deformed. Accordingly, the valve shaft 21 is not subjected to the elastic force of the upper coil spring 74 and is not subjected to the elastic force of the lower coil spring 77, and thus the rotational resistance of the valve shaft 21 is reduced, and the power consumption of the motor can be suppressed. Further, at least one of the upper coil spring 74 and the lower coil spring 77 may be elastically deformed from the valve-closed state to the valve-open state.

When the pulse power supply to the stator 50 is continued and the valve shaft 21 is continued to rotate, the washer 73 placed on the upper end of the upper coil spring 74 is further separated from the flange-like portion 21c, and the upper end of the lower coil spring 77 is still in contact with the lower surface of the partition wall 71b, and the seat member 72 is in the valve-opened state farthest from the valve seat 11e. At this time, as shown in fig. 3, the upper surface of the seat member 72 abuts against the lower surface of the guide rod 15, and more specifically, the second tapered surface 72g is seated on and fixed to the first tapered surface 15e. Therefore, even if the refrigerant flows into the valve chamber VC from the second pipe T2 so as to strongly apply a force in a direction intersecting the axis L to the seat member 72, the vibration of the valve body unit 70 can be suppressed. Therefore, the occurrence of noise can be effectively suppressed without increasing the rigidity of each portion or reducing the gap of the sliding portion, and the electrically operated valve 1 excellent in energy saving effect can be provided.

At this time, since the elastic force of the lower coil spring 77 is transmitted to the seat member 72 via the sleeve 71, the buffer function of relaxing the driving force of the motor is exerted, and the second tapered surface 72g of the seat member 72 rotating with the valve shaft 21 can be restrained from biting into the first tapered surface 15e.

When the pulse power supply is further continued, the valve-opening-direction movable stopper 36 abuts against and is locked to the valve-opening-direction fixed stopper 56, whereby the rotation and the elevation of the rotor 30 and the valve shaft 21 are forcibly stopped.

In contrast, when pulse power having reverse characteristics is supplied from the external power supply circuit to the stator 50 in this valve-open state, the rotor 30 and the valve shaft 21 are driven to rotate in the other direction, and the valve shaft 21 and the valve body unit 70 are lowered while rotating via the screw feed mechanism constituted by the female screw hole 15c and the male screw portion 21b, so that the upper coil spring 74 and the lower coil spring 77 are in a specific intermediate state in which they are not elastically deformed.

When the spring holder member 76 moves downward together with the valve shaft 21 and passes through a certain intermediate state, the sleeve 71 is biased downward by the elastic force of the upper coil spring 74, and then the seat surface 72c of the seat member 72 is seated on the valve seat 11e of the valve seat member 11. When the valve shaft 21 is further displaced downward from this state, the tapered portion 21g of the valve shaft 21 enters the cylindrical hole 72d, and the valve is closed to cover the tapered portion. Thereby, the flow of the refrigerant from the valve chamber VC toward the first pipe T1 side is restricted.

As described above, the present embodiment is a valve-closing-free structure, but may be a completely-closed structure (valve-closing structure).

At the point in time when the seat surface 72c of the seat member 72 is seated on the valve seat 11e of the valve seat member 11, the movable stopper 35 for closing direction and the fixed stopper 55 for closing direction do not yet come into contact with each other, and the valve shaft 21 and the rotor 30 further rotate and descend. Since the valve body unit 70 remains stationary even if the valve shaft 21 descends, the upper coil spring 74 is compressed accordingly, and the pressing force between the seat surface 72c and the valve seat 11e increases.

Subsequently, when the rotor 30 further rotates and the valve shaft 21 descends, the stopper portion 35a of the movable stopper 35 for the valve closing direction abuts against the fixed stopper 55 for the valve closing direction. By the abutment of these stoppers, the lowering of the valve shaft 21 is forcibly stopped even if the energization to the stator 50 is continued.

The present specification includes the following disclosure of the utility model.

(utility model A)

An electrically operated valve, comprising:

a valve element unit disposed on the valve shaft so as to be displaceable in an axial direction with respect to the valve shaft,

(utility model B)

The electric valve according to utility model a, wherein the hollow cylindrical portion has a first tapered surface, and the seat member has a second tapered surface that seats on the first tapered surface when the seat member is separated from the valve seat by a maximum distance.

(utility model C)

The electric valve according to the utility model a or B is characterized in that the valve body has a pipe through which fluid flows into the valve body, and in the axial direction of the valve body, the valve seat side end portion of the hollow cylindrical portion is disposed on the valve seat side with respect to an upper end of an inner periphery of an inner end of the pipe.

(utility model D)

The electrically operated valve according to any one of the utility models a to C, wherein the communication hole formed in the sleeve is exposed from the hollow cylinder portion when the seat member is seated on the valve seat.

(utility model E)

The electric valve according to any one of the utility models a to D, characterized in that a first spring member that urges the sleeve toward the valve opening side with respect to the valve axis is attached, and when the seat member abuts against the guide member, the elastic force of the first spring member is transmitted to the seat member.

(utility model F)

The electric valve according to utility model E is characterized in that a second spring member that biases the sleeve with respect to the valve axis toward the valve closing side is attached, and when the seat member is seated on the valve seat, the elastic force of the second spring member is transmitted to the seat member.

(utility model G)

The electrically operated valve according to utility model F is characterized in that the first spring member and the second spring member are not elastically deformed in an intermediate state between the valve-opening state and the valve-closing state.

The electrically operated valve according to any one of the utility models a to G, wherein the motor includes: a rotor fixed to the valve shaft; and a stator capable of driving the rotor to rotate.

Claims

1. An electrically operated valve, comprising:

a valve core unit connected with the valve shaft,

2. The electrically operated valve as set forth in claim 1, wherein,

the hollow cylindrical portion has a first tapered surface, and the seat member has a second tapered surface that seats against the first tapered surface when the seat member is at a maximum distance from the valve seat.

3. The electrically operated valve as set forth in claim 1, wherein,

the valve body includes a pipe through which fluid flows into the valve body, and the valve seat side end of the hollow cylindrical portion is disposed on the valve seat side of the upper end of the inner periphery of the inner end of the pipe in the axial direction of the valve body.

4. The electrically operated valve as set forth in claim 1, wherein,

when the seat member is seated on the valve seat, a communication hole formed in the sleeve is exposed from the hollow cylinder.

5. The electrically operated valve as set forth in claim 1, wherein,

a first spring member is attached to bias the sleeve toward the valve opening side with respect to the valve axis, and when the seat member abuts against the guide member, the elastic force of the first spring member is transmitted to the seat member.

6. The electrically operated valve as set forth in claim 5, wherein,

a second spring member is attached to bias the sleeve toward the valve closing side with respect to the valve axis, and the elastic force of the second spring member is transmitted to the seat member when the seat member is seated on the valve seat.

7. The electrically operated valve as set forth in claim 6, wherein,

in an intermediate state between the valve-open state and the valve-closed state, the first spring member and the second spring member are not elastically deformed.

8. The electrically operated valve as claimed in any one of claims 1 to 7, characterized in that,

the motor has: a rotor fixed to the valve shaft; and a stator capable of driving the rotor to rotate.