JP2024046974A - Motor-operated valve - Google Patents

Abstract

An object of the present invention is to provide an electrically operated valve capable of suppressing wear on the valve body or valve seat. [Solution] The motor-operated valve 1 comprises a valve stem holder 15 movable in the axial direction relative to a valve body 10 having a valve seat 10d, a valve body portion 21d movable toward and away from the valve seat, a valve stem 21 movable in the axial direction relative to the valve body, a driven member 37 moving in the axial direction together with the valve stem, a spring stopper 36 attached to the valve stem, a spring member 39 biasing the valve stem in a direction in which the valve body portion approaches the valve seat, and a spring receiving portion 38 abutting one end of the spring member, and when the valve stem holder abuts against the driven member, a driving force in a direction in which the valve body portion moves away from the valve seat is transmitted from the valve stem holder via the driven member to the valve stem, and the spring receiving portion is sandwiched between the valve stem holder and the spring member at a first axial position of the valve stem including at least the fully closed position, and is sandwiched between the spring stopper and the spring member at a second axial position of the valve stem including at least the fully open position. [Selected Figure] Figure 1

Description

The present invention relates to a motor-operated valve.

For example, the motor-driven electric valve shown in Patent Document 1 has a valve shaft connected to the rotor of a stepping motor. Due to the action of a screw mechanism consisting of a male thread and a female thread that are screwed together, the valve shaft rotates with the rotor and simultaneously displaces in the axial direction, thereby increasing or decreasing the gap between the valve body and the valve seat, thereby controlling the flow rate.

In such motor-operated valves, a valve-closing spring is disposed between the valve stem holder and the valve stem with the valve body, and the biasing force of the valve-closing spring acts between the valve stem holder and the valve body in both the closed state where the valve body is seated on the valve seat, and the open state where the valve body is separated from the valve seat. Due to the action of this biasing force, the valve body in the open state rotates in conjunction with the rotation of the valve stem.

JP 2011-208716 A

Here, when the valve disc sits on the valve seat, frictional force is generated between the two, and the rotation of the valve disc eventually stops. However, because the frictional force between the valve disc and the valve seat increases according to the axial force pressing the valve disc against the valve seat, the valve disc continues to rotate in contact with the valve seat until a frictional force sufficient to resist the rotational torque of the valve disc is generated, which may cause wear between the valve disc and the valve seat.

The present invention aims to provide an electrically operated valve that can reduce wear on the valve body or valve seat.

The motor-operated valve of the present invention comprises:
A valve body having a valve seat;
a valve stem holder that is movable in an axial direction relative to the valve body;
a valve shaft including a valve body portion that is movable toward and away from the valve seat and that is movable in an axial direction relative to the valve body;
a driven member that moves in an axial direction together with the valve stem;
a spring stopper attached to the valve stem;
a spring member that biases the valve shaft in a direction in which the valve body portion approaches the valve seat;
a spring receiving portion that abuts against one end of the spring member,
When the valve stem holder comes into contact with the driven member, a driving force is transmitted from the valve stem holder to the valve stem via the driven member in a direction in which the valve body portion moves away from the valve seat,
The spring support portion is sandwiched between the valve stem holder and the spring member at a first axial position of the valve stem which includes at least the fully closed position, and is sandwiched between the spring stopper and the spring member at a second axial position of the valve stem which includes at least the fully open position.

The present invention provides an electrically operated valve that can suppress wear on the valve body or valve seat.

FIG. 1 is a vertical cross-sectional view of a motor-operated valve according to an embodiment of the present invention, showing a fully closed state. FIG. 2 is a vertical cross-sectional view of the motor-operated valve according to the embodiment of the present invention, showing an intermediate state between a fully closed state and a fully open state. FIG. 3 is a vertical cross-sectional view of the motor-operated valve according to the embodiment of the present invention, showing an intermediate state between a fully closed state and a fully open state. FIG. 4 is a vertical cross-sectional view of the motor-operated valve according to the embodiment of the present invention, showing a fully open state. FIG. 5 is a graph showing the orifice flow rate on the vertical axis and the number of pulses supplied to the stator on the horizontal axis.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 4 are vertical cross-sectional views of a motor-operated valve 1 according to an embodiment of the present invention. Here, the term "upper" refers to the rotor side of the motor-operated valve 1, and the term "lower" refers to the valve seat side relative to the rotor.

(Configuration of motor-operated valve)
The motor-operated valve 1 comprises a cylindrical valve body 10 with a bottom that is open at the top, a cylindrical can 45 with a top attached to the top of the valve body 10, a valve stem holder 15 fixed to the inside of the valve body 10, a valve stem 21 disposed inside the valve stem holder 15, a rotor 30 connected and fixed to the valve stem holder 15 so as to be integrally rotatable, and a stator (not shown) fitted onto the outer periphery of the can 45 to rotate the rotor 30. Here, the rotor 30 and the stator form a stepping motor. The axis of the motor-operated valve 1 is designated as L.

The valve body 10 is formed by connecting a hollow cylindrical portion 10a and a bottom wall portion 10b. A through hole 10c is formed in the center of the bottom wall portion 10b. The through hole 10c is composed of a first tapered portion 10d formed on the upper end side and decreasing in diameter as it approaches downward, a second tapered portion 10e connected to the lower end of the first tapered portion 10d and increasing in diameter as it approaches downward, and a cylindrical hole 10f connected to the lower end of the second tapered portion 10e. One or more V-shaped grooves 10h are formed in the first tapered portion 10d in the radial direction. The first tapered portion 10d forms the valve seat.

A circular groove 10g is formed around the through hole 10c on the underside of the bottom wall portion 10b, and the end of the vertical pipe T1 is inserted into the circular groove 10g and connected by brazing or the like.

A stepped opening 10i is formed in the hollow cylindrical portion 10a of the valve body 10, and a horizontal pipe T2 is inserted into the stepped opening 10i so that its end abuts against the inner step, and is connected by brazing or the like. The axis of the stepped opening 10i is O. The axis O is perpendicular to the axis L.

A flange member 18 is fixed by brazing to the outer periphery of the hollow cylindrical portion 10a of the valve body 10 near the upper end, and the lower end of the can 45 is welded to the outer periphery of the flange member 18, thereby integrating the valve body 10 and the can 45 in a sealed state. The inside of the hollow cylindrical portion 10a forms the valve chamber VC.

The rotor 30, which is placed inside the can 45, is magnetized and molded into a hollow cylinder by mixing magnetic metal powder and resin, and the connection ring 31 is coaxially fixed by insert molding so that it protrudes radially inward from its inner circumference. The inner circumference of the connection ring 31 is fixed to the outer circumference of the valve stem holder 15.

The valve stem holder 15 is made up of a holder cylindrical portion 15a and an upper wall 15b connected together, with a thin crimped cylindrical portion 15c protruding upward from the upper surface of the upper wall 15b. With the inner periphery of the connection ring 31 fitted into the outer periphery of the crimped cylindrical portion 15c, the upper end of the crimped cylindrical portion 15c is plastically deformed radially outward to crimp it, thereby connecting the connection ring 31 to the valve stem holder 15.

The upper wall 15b of the valve stem holder 15 has a circular recess 15d with a circular recess on the upper surface, and a central opening 15e formed in the center of the circular recess 15d and penetrating the upper wall 15b. The holder cylindrical portion 15a also has a female thread portion 15f on its inner circumference near its lower end.

A cylindrical upper stopper member 34 is joined to the outer peripheral surface of the holder cylindrical portion 15a by insert molding, and its lower end is positioned below the lower end of the holder cylindrical portion 15a. One point on the lower surface of the upper stopper member 34 protrudes downward in the circumferential direction, thereby forming the upper stopper portion 34a.

The guide bush 33 is made up of a reduced diameter cylindrical portion 33a arranged inside the holder cylindrical portion 15a and an expanded diameter cylindrical portion 33b with a larger diameter than the reduced diameter cylindrical portion 33a. A male threaded portion 33c that engages with the female threaded portion 15f of the valve shaft holder 15 is formed on the outer periphery of the reduced diameter cylindrical portion 33a. The outer periphery of the reduced diameter cylindrical portion 33a above the male threaded portion 33c fits relatively slidably against the inner periphery of the holder cylindrical portion 15a.

The enlarged diameter cylindrical portion 33b is attached to the valve body 10 by press-fitting its outer periphery into the inner periphery of the hollow cylindrical portion 10a. A communication hole 33d that connects the inside and outside of the guide bush 33 is formed near the boundary between the reduced diameter cylindrical portion 33a and the enlarged diameter cylindrical portion 33b.

A circular lower stopper member 35 is joined by insert molding to the outer peripheral surface of the enlarged diameter cylindrical portion 33b near the upper end. One circumferential point on the upper surface of the lower stopper member 35 protrudes upward, forming the lower stopper portion 35a.

The cylindrical valve shaft 21 is made up of a small diameter shaft portion 21a, a large diameter shaft portion 21b that is larger than the small diameter shaft portion 21a, a medium diameter shaft portion 21c that is larger in diameter than the small diameter shaft portion 21a but smaller in diameter than the large diameter shaft portion 21b, and a valve body portion 21d.

A spring stopper 36, which is a cylindrical member, is attached (fixed) by press-fitting or welding to a predetermined position on the outer periphery of the small diameter shaft portion 21a. The spring stopper 36 is inserted into the central opening 15e of the valve shaft holder 15 so as to be movable relative to the central opening 15e.

A hollow cylindrical push nut (driven member) 37 is attached by press fitting to the top of the spring stopper 36. The push nut 37 has a first inner peripheral surface 37a and a second inner peripheral surface 37b that is larger in diameter than the first inner peripheral surface 37a, and the outer peripheral surface of the spring stopper 36 is fitted into the second inner peripheral surface 37b. In other words, the push nut 37 is fixed directly to the valve shaft 21 or indirectly via the spring stopper 36, and they move together in the axial direction. The lower end of the push nut 37 can enter the circular recess 15d of the valve shaft holder 15. The push nut 37 and the spring stopper 36 may be integrated.

In addition, the spring stopper 36 does not need to be fixed to the valve shaft 21 as long as the axial length is specified, and may be attached so as to be movable relative to the valve shaft 21 in the axial direction, for example, with a clearance fit dimensional relationship. In that case, however, the push nut 37 must be fixed (fixed) to a predetermined position by, for example, press fitting, welding, or melting to the valve shaft 21. In this case, the spring stopper 36 is movable relative to the push nut 37 in the axial direction at a first axial position of the valve shaft 21 including at least the fully closed position described below. In addition, at a second axial position of the valve shaft 21 including at least the fully open position, the upper end of the spring stopper 36 abuts against the step between the first inner circumferential surface 37a and the second inner circumferential surface 37b of the push nut 37, and is fixed in the axial direction to the valve shaft 21. Furthermore, if the spring stopper 36 is not fixed to the valve shaft 21, the washer 38 and the spring stopper 36, which will be described later, can be integrated and made movable relative to the valve shaft 21.

A return spring 40 is fitted around the push nut 37. When the rotor 30 rotates in one direction and the female threaded portion 15f and the male threaded portion 33c become unscrewed, the return spring 40 urges the valve stem holder 15 downward against the can 45, thereby urging the female threaded portion 15f and the male threaded portion 33c to re-screw when the rotor 30 rotates in the other direction.

The large diameter shaft portion 21b of the valve shaft 21 is fitted to the inner circumference of the guide bush 33 so as to be movable relative to the guide bush 33 in the axial and rotational directions. A valve-closing spring (spring member) 39 is arranged between the outer circumference of the small diameter shaft portion 21a and the inner circumference of the guide bush 33. The lower end of the valve-closing spring 39 abuts against the step between the small diameter shaft portion 21a and the large diameter shaft portion 21b, and the upper end of the valve-closing spring 39 abuts against the lower surface of a washer (spring bearing portion) 38 fitted to the small diameter shaft portion 21a. The washer 38, which is an annular plate material, has an outer diameter smaller than the inner diameter of the holder cylindrical portion 15a and larger than the inner diameter of the reduced diameter cylindrical portion 33a, and is arranged between the upper end of the guide bush 33 and the upper wall 15b of the valve shaft holder 15 so as to be movable relative to the small diameter shaft portion 21a in the axial and rotational directions.

The valve body portion 21d of the valve shaft 21 is composed of a first valve body tapered portion 21e that reduces in diameter as it approaches the bottom and can be seated on the first tapered portion 10d, a second valve body tapered portion 21f that reduces in diameter as it approaches the bottom and has a smaller inclination angle with respect to the axis L than the first valve body tapered portion 21e, and a third valve body tapered portion 21g that reduces in diameter as it approaches the bottom and has a larger inclination angle with respect to the axis L than the second valve body tapered portion 21f.

During assembly, the position adjustment of the valve shaft 21 and the spring stopper 36 is performed by rotating the rotor 30 in the valve closing direction while lowering the valve shaft 21 before assembling the can 45, the return spring 40, and the push nut 37, so that the first valve body tapered portion 21e is seated on the first tapered portion 10d. After that, a predetermined torque is applied in the same direction, and then the rotor 30 is rotated in the opposite direction by a specified amount, so that the lower end of the spring stopper 36 abuts against the upper surface of the washer 38 at that position (the position shown in Figure 2), and the spring stopper 36 is fitted to the valve shaft 21 by press fitting, or is positioned and fixed by a method such as welding. After that, the push nut 37 is positioned and fixed at a predetermined position on the valve shaft 21 by press fitting, and the return spring 40 and the can 45 are attached. However, the method of assembling the spring stopper 36 is not limited to the above. For example, the spring stopper 36 may be attached using a jig or the like so that the lower end of the spring stopper 36 is at a predetermined position from the upper end of the valve shaft 21 alone.

(Operation of motor-operated valve)
Next, the valve opening operation of the motor-operated valve 1 will be specifically described with reference to FIGS.
In this embodiment, the position of the valve stem 21 where the spring stopper 36 does not contact the washer 38 (including at least the fully closed position) is defined as the "first axial position", and the position of the valve stem 21 where the spring stopper 36 contacts the washer 38 (including at least the fully open position) is defined as the "second axial position". Here, the "fully open position" refers to the position where the first valve body tapered portion 21e is the furthest from the first tapered portion 10d, and in the motor-operated valve 1, it is the position (upper end position) where the upward movement (valve opening direction) of the valve stem holder 15 is stopped. On the other hand, the "fully closed position" refers to the position where the first valve body tapered portion 21e is the closest to or most strongly pressed against the first tapered portion 10d in a state of contact, and in the motor-operated valve 1, it is the position (lower end position) where the downward movement (valve closing direction) of the valve stem holder 15 is stopped by the engagement between the upper stopper portion 34a and the lower stopper portion 35a. In the figure, the relative positional relationship between the upper stopper portion 34a and the lower stopper portion 35a is exaggerated and differs from the actual positional relationship.

Figure 5 is a graph showing the orifice flow rate (flow rate of refrigerant passing through the through hole 10c) on the vertical axis and the number of pulses supplied to the stator on the horizontal axis. In Figure 5, p1 corresponds to the fully closed position shown in Figure 1, p2 corresponds to the position shown in Figure 2, p3 corresponds to the position shown in Figure 3, p4 corresponds to a position between Figures 3 and 4, and p5 corresponds to the fully open position shown in Figure 4. Here, the "second axial position" is the range from the fully open position (p5) through positions p4 and p3 to position p2, and the valve opening point is located within the range of the "second axial position". In contrast, the "first axial position" is the range from position p2 (more precisely, slightly closer to the closing side than p2) to the fully closed position (position p1: 0 pulse number).

First, assume that refrigerant (fluid) is entering the valve chamber VC from the horizontal pipe T2, and that the motor-operated valve 1 is in the fully closed state shown in Figure 1. At this time, there is a gap between the spring stopper 36 and the washer 38, so that the upper surface of the washer 38 is in contact with the lower surface of the upper wall 15b of the valve stem holder 15.

In such a completely closed state, as shown in FIG. 1, the lower end of the push nut 37 is separated from the bottom surface of the circular recess 15d. In addition, the upper end of the valve-closing spring 39 abuts against the lower surface of the washer 38, and its lower end abuts against the step between the small diameter shaft portion 21a and the large diameter shaft portion 21b of the valve shaft 21, so that the valve shaft 21 is urged downward by the urging force of the valve-closing spring 39. As a result, the first valve body tapered portion 21e is pressed toward the first tapered portion 10d with a predetermined surface pressure and seats, restricting the flow of refrigerant from the valve chamber VC through the through hole 10c toward the vertical pipe T1. In this embodiment, since a groove 10h is formed in the first tapered portion 10d, a certain amount of refrigerant flows through the groove 10h even in the completely closed state. However, the groove 10h does not have to be provided.

When pulsed power is supplied from an external power supply circuit to the stator (not shown) from this completely closed valve state, the rotor 30 and the valve shaft 21 are rotated in one direction, and the valve shaft 21 and the valve shaft holder 15 rotate and rise in response via the screw feed mechanism consisting of the female threaded portion 15f and the male threaded portion 33c. However, as shown in FIG. 2, the valve shaft 21 remains biased downward by the biasing force of the valve-closing spring 39, so the first valve body tapered portion 21e continues to seat on the first tapered portion 10d, and the refrigerant passing through the through hole 10c remains restricted.

At this time, the valve shaft 21 receives a rotational torque from the valve shaft holder 15 via the washer 38 and the valve-closing spring 39. However, because the biasing force of the compressed valve-closing spring 39 is relatively strong, the frictional force acting between the first valve body tapered portion 21e and the first tapered portion 10d is high, and the valve shaft 21 does not rotate. However, when the frictional force can no longer resist the rotational torque, the valve shaft 21 rotates, but the amount of wear at that time is small.

When a predetermined number of pulses (for example, 15 pulses) are supplied to the stator from the fully closed state, the lower end of the spring stopper 36 abuts against the upper surface of the washer 38, and as shown in FIG. 3, the washer 38 is separated from the upper wall 15b of the valve stem holder 15. As a result, the upper end of the valve-closing spring 39 is supported by the spring stopper 36 via the washer 38. That is, when the valve stem 21 rises from the first axial position to the second axial position, the spring stopper 36 supports the biasing force of the valve-closing spring 39. As a result, the torque transmission between the valve stem 21 and the valve stem holder 15 is substantially eliminated, so that wear of both can be suppressed even before the first valve body tapered portion 21e is separated from the first tapered portion 10d. In particular, when a groove 10h is formed in the first tapered portion 10d as in this embodiment, the sharp edges of the groove 10h can cause wear on the first valve body tapered portion 21e, which can increase the amount of wear, making the function of the spring stopper 36 effective.

When the lower end of the push nut 37 enters the circular recess 15d and abuts against its bottom surface as the valve stem holder 15 rises, a driving force is transmitted in the valve opening direction via the push nut 37, and the valve stem 21 begins to rise together with the valve stem holder 15. As the valve stem 21 rises, the first valve body tapered portion 21e moves away from the first tapered portion 10d, opening the through hole 10c. As a result, the refrigerant that has entered the valve chamber VC from the horizontal pipe T2 flows through the gap between the first valve body tapered portion 21e and the first tapered portion 10d, and through the through hole 10c, into the first pipe T1.

At this time, the lift amount of the valve stem 21 is determined according to the pulse power supply to the stator, so the flow rate of the refrigerant can be controlled. By continuing the pulse power supply, the valve stem 21 finally reaches a fully open state as shown in FIG. 4. In the second axial position, the valve stem 21 is not supported axially by the valve stem holder 15, so there is a risk that the valve stem 21 may wobble in the axial direction. Therefore, in order to suppress the wobbling of the valve stem 21, the lower end of the push nut 37 may be extended downward and engaged with the side wall of the circular recess 15d of the valve stem holder 15 even in the second axial position, providing a sliding resistance between them.

On the other hand, when a pulse current with reverse characteristics is supplied to the stator from an external power supply circuit from this fully open state, the rotor 30 and the valve shaft 21 are driven to rotate in the other direction, and the valve shaft 21 rotates and descends together with the valve shaft holder 15 via the screw feed mechanism described above.

Even if the valve stem holder 15 descends, while the washer 38 is supported by the spring stopper 36 (when in the second axial position), almost no rotational torque is transmitted from the valve stem holder 15 to the valve stem 21. Therefore, even if the first valve body tapered portion 21e and the first tapered portion 10d are in contact with each other, wear on both can be suppressed.

When the valve stem holder 15 descends a specified amount, the first valve body tapered portion 21e seats on the first tapered portion 10d. This restricts the flow of refrigerant from the valve chamber VC toward the vertical pipe T1.

At this point, the upper stopper portion 34a has not yet come into contact with the lower stopper portion 35a, and the rotation and descent of the rotor 30 and the valve shaft 21 is not stopped, and pulse power supply continues until the valve-closing spring 39 is compressed by a predetermined amount. As a result, the first valve body tapered portion 21e is restrained from rotating while remaining seated on the first tapered portion 10d, while the rotor 30, valve shaft holder 15, etc. continue to rotate and descend.

At this time, the valve stem holder 15 descends relative to the seated valve stem 21, causing the valve-closing spring 39 to contract and be compressed, thereby absorbing the downward force of the valve stem holder 15. After that, when the amount of compression of the valve-closing spring 39 reaches a predetermined amount, the upper stopper portion 34a abuts and engages the lower stopper portion 35a, the rotor 30 reaches its lowest position, and the descent of the rotor 30 and valve stem holder 15 is forcibly stopped even if pulse power supply to the stator continues.

In this way, even after the first valve body tapered portion 21e is seated on the first tapered portion 10d and the through hole 10c is closed, the rotor 30 and the valve stem holder 15 continue to rotate downward until the control origin position is reached where the upper stopper portion 34a abuts and engages with the lower stopper portion 35a, compressing the valve-closing spring 39. Therefore, the first valve body tapered portion 21e is strongly pressed against the first tapered portion 10d by the biasing force of the valve-closing spring 39, reliably preventing refrigerant leakage, etc.

The specific configuration of the motor-operated valve is not limited to the above-mentioned embodiments, and the present invention naturally includes design changes that do not deviate from the spirit of the present invention.

This specification includes the disclosure of the following inventions.
(First aspect)
A valve body having a valve seat;
a valve stem holder that is movable in an axial direction relative to the valve body;
a valve shaft including a valve body portion that is movable toward and away from the valve seat and that is movable in an axial direction relative to the valve body;
a driven member that moves in an axial direction together with the valve stem;
a spring stopper attached to the valve stem;
a spring member that biases the valve shaft in a direction in which the valve body portion approaches the valve seat;
a spring receiving portion that abuts against one end of the spring member,
When the valve stem holder comes into contact with the driven member, a driving force is transmitted from the valve stem holder to the valve stem via the driven member in a direction in which the valve body portion moves away from the valve seat,
the spring receiving portion is sandwiched between the valve stem holder and the spring member at a first axial position of the valve stem including at least a fully closed position, and is sandwiched between the spring stopper and the spring member at a second axial position of the valve stem including at least a fully open position.
A motor-operated valve.

(Second embodiment)
The valve stem holder has a hollow cylindrical portion and a wall formed at one end of the hollow cylindrical portion.
10. The motor-operated valve of claim 1,

(Third Form)
The spring bearing portion is made of an annular plate material through which the valve stem is inserted and abuts against the wall at the first axial position.
2. The motor-operated valve according to claim 1,

(Fourth Form)
The spring stopper is fixed to the valve shaft.
The motor-operated valve according to any one of the first to third aspects,

(Fifth Form)
The spring stopper has a specified length and is attached to the valve shaft so as to be movable relative to the valve shaft in an axial direction.
The driven member is fixed to the valve stem.
The motor-operated valve according to any one of the first to third aspects,

(Sixth Form)
the spring stopper is movable in the axial direction relative to the driven member at a first axial position of the valve shaft, and is fixed in the axial direction by abutting against the driven member at a second axial position of the valve shaft.
5. The motor-operated valve of claim 5,

(Seventh Form)
The spring receiving portion is integral with the spring stopper.
The motor-operated valve of the sixth aspect,

(Eighth embodiment)
The valve seat has a groove in a radial direction through which a fluid can pass when the valve body portion is seated.
The motor-operated valve according to any one of the first to seventh aspects,

Reference Signs List 1 Motor-operated valve 10 Valve body 10d First tapered portion 10h Groove 15 Valve stem holder 15a Holder cylindrical portion 15b Upper wall 15d Circular recess 15e Central opening 21 Valve stem 21d Valve body portion 33 Guide bush 36 Spring stopper 37 Push nut 38 Washer 39 Valve-closing spring 30 Rotor VC Valve chamber

Claims (8)

A valve body having a valve seat;
a valve stem holder that is movable in an axial direction relative to the valve body;
a valve shaft including a valve body portion that is movable toward and away from the valve seat and that is movable in an axial direction relative to the valve body;
a driven member that moves in an axial direction together with the valve stem;
a spring stopper attached to the valve stem;
a spring member that biases the valve shaft in a direction in which the valve body portion approaches the valve seat;
a spring receiving portion that abuts against one end of the spring member,
When the valve stem holder comes into contact with the driven member, a driving force is transmitted from the valve stem holder to the valve stem via the driven member in a direction in which the valve body portion moves away from the valve seat,
the spring receiving portion is sandwiched between the valve stem holder and the spring member at a first axial position of the valve stem including at least a fully closed position, and is sandwiched between the spring stopper and the spring member at a second axial position of the valve stem including at least a fully open position.
A motor-operated valve. The valve stem holder has a hollow cylindrical portion and a wall formed at one end of the hollow cylindrical portion.
2. The motor-operated valve according to claim 1 . The spring bearing portion is made of an annular plate material through which the valve stem is inserted and abuts against the wall at the first axial position.
3. The motor-operated valve according to claim 2. The spring stopper is fixed to the valve shaft.
2. The motor-operated valve according to claim 1 . The spring stopper has a specified length and is attached to the valve shaft so as to be movable relative to the valve shaft in an axial direction.
The driven member is fixed to the valve stem.
2. The motor-operated valve according to claim 1 . the spring stopper is movable in the axial direction relative to the driven member at a first axial position of the valve shaft, and is fixed in the axial direction by abutting against the driven member at a second axial position of the valve shaft.
6. The motor-operated valve according to claim 5. The spring receiving portion is integral with the spring stopper.
7. The motor-operated valve according to claim 6. The valve seat has a groove in a radial direction through which a fluid can pass when the valve body portion is seated.
The motor-operated valve according to any one of claims 1 to 7.

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