JP7266639B2 - electric valve - Google Patents

Description

The present invention relates to an electrically operated valve used in refrigeration cycle systems and the like.

2. Description of the Related Art Electric valves used in packaged air conditioners, room air conditioners, refrigerators, etc. are conventionally known (for example, Patent Document 1). In this motor operated valve 100, for example, as shown in FIG. 7, when the stepping motor is driven to rotate the rotor 103, the screw feeding action of the female thread 131a and the male thread 121a causes the valve body 114 to move in the direction of the central axis L'. do. As a result, the opening and closing of the valve port 121 is adjusted, and the flow rate of the refrigerant flowing in from the pipe joint 111 and flowing out from the pipe joint 112 is controlled.

JP-A-10-148420

By the way, currently, in the technical field of air conditioners, refrigerators, etc., improvement of energy saving performance is being actively studied, and similar energy saving performance is required for electric valves used in such refrigeration cycle systems. There is a background. Here, the performance required of the motor-operated valve includes improved controllability of minute flow rates in the low opening range immediately after the valve body is separated from the valve seat, and reduction of variation in flow rates.

In particular, for motor-operated valves used in room air conditioners and small commercial air conditioners, it is desirable to reduce the flow rate at the minimum opening to the limit in order to control minute flow rates in the low opening range. ing.

In this regard, in the above-described electrically operated valve 100, as shown in FIG. 8(a), in the valve body 114, between the first taper 114a with a relatively large angle seated on the valve seat 120 and the third taper 114c, Attempts have been made to improve the flow rate control in the low opening range by forming the second taper 114b with an extremely small taper angle (the angle of the inclined surface of the taper with respect to the central axis L').

FIG. 8(b) is a graph showing the flow rate characteristics of the motor operated valve 100 in the low opening range. In FIG. 8B, the horizontal axis of the graph represents the application amount of pulses applied to the stepping motor to move the valve body 114, and the vertical axis of the graph represents the flow rate. The origin of the graph represents the valve closed state at 0 pulse. Here, the polygonal line A in the drawing represents the change in the flow rate when the valve element 114 is used. In addition, in the figure, as a contrast with the polygonal line A, a polygonal line B is shown that represents the change in the flow rate when the valve body 114' in which the second taper 114b is not formed is used as shown in FIG. .

According to FIG. 8(b), along line B, there is a sudden change from the rising flow rate region 201 determined by the first taper 114'a to the flow rate region 203 determined by the third taper 114'c. On the other hand, in the polygonal line A, after the rising flow rate region 201, the second taper 114b with a small angle controls the degree of increase in the flow rate in the flow rate region 202 for a while. Change can be suppressed.

However, in order to improve the controllability of the minute flow rate in the originally low opening range, the value of the maximum flow rate X in the rising flow rate region 201 immediately after the valve body 114 leaves the valve seat 120 must be suppressed. In this regard, in the electric valve 100, even if the second taper 114b is provided, this problem cannot be solved.

Here, as shown in FIG. 10( a ), it is conceivable to seat a taper 214 c that controls the flow rate of the valve element 214 on the valve seat 220 . In this case, as shown in FIG. 10(b), the flow rate in the rising flow rate region 210 can be made extremely small, but the valve element 214 bites into the valve seat 220, making it difficult to open the valve. is disturbed.

Also, as shown in FIG. 11(a), it is conceivable to reduce the rising flow rate by bringing the diameter D1 of the boundary between the first taper 314a and the second taper 314b closer to the inner diameter D2 of the valve seat 320. FIG. However, when the boundary between the first taper 314a and the second taper 314b is seated as shown in the enlarged view of FIG. There is also a possibility that the valve body 314 will bite into the valve seat 320 as described above.

In addition, since a corner R315 is actually formed at such a boundary during machining, when the valve element 314 is seated on the valve seat 320, the corner R315 portion may come into contact with the valve seat 320. . The size and shape of the corner R315 is likely to vary due to the processing of the valve body 314, so if the corner R315 comes into contact with the valve seat 320 when seated, the flow rate characteristics at the start will differ for each motor operated valve. Problems can arise.

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor-operated valve that can accurately control minute flow rates in a low opening range.

The motor operated valve of the present invention is
The rotary motion of the rotor is converted into linear motion by threading the male screw member and the female screw member, and based on this linear motion, the stainless steel valve body accommodated in the valve body is moved in the axial direction. being a valve,
Having a stainless steel valve seat having a seating portion on which the valve body is seated when the valve is closed, and a valve port into which the valve body is inserted;
the valve port has an inner peripheral surface parallel to the central axis of the motor operated valve,
A recessed area recessed from the valve body side is formed on the rotor side of the valve port,
The seating portion is a rotor-side edge of the recessed region that is a boundary between the recessed region and the top surface of the valve seat,
The valve body
a first taper that abuts against the seating portion in the valve closed state;
a second taper located ahead of the first taper and surrounded by the inner peripheral surface in the valve closed state,
the first taper of the valve body abuts against the edge portion in the valve closed state;
In a state in which the first taper is in contact with the seat portion, a space having a width wider than the width of the clearance formed between the valve port and the second taper is formed between the seat portion and the clearance. is formed in
A gap between the inner peripheral surface of the valve port and the second taper is the smallest in the gap between the inner peripheral surface of the valve port and the valve body.

As a result, the function of the first taper is limited to the seating function as much as possible, and the flow rate can be controlled mainly by the second taper, so that a minute flow rate can be accurately controlled in the low opening range.

Further, the motor operated valve of the present invention is
The valve body is provided with a cylindrical rod portion at a position closer to the rotor than the first taper, and the axial length of the cylindrical rod portion is larger than the outer diameter of the cylindrical rod portion. do.
Further, the motor operated valve of the present invention is
The valve body is characterized in that no taper is provided on the side opposite to the second taper from the upper end of the first taper in the central axis direction .

Further, the motor operated valve of the present invention is
A valve chamber is provided inside the valve main body.
Further, the motor operated valve of the present invention is
The valve body is characterized by comprising a first pipe joint that communicates with the valve chamber.

Further, the motor operated valve of the present invention is
A lower end of the inner surface of the first pipe joint is located at a position higher than a position where the first taper and the seating portion abut when the valve is closed.
Further, the motor operated valve of the present invention is
The first pipe joint is characterized by being made of stainless steel or copper.

Further, the motor operated valve of the present invention is
An end portion of the first pipe joint on the valve chamber side protrudes into the valve chamber.
Further, the motor operated valve of the present invention is
the valve seat includes a second pipe joint that communicates with the valve chamber through the valve port;
The second pipe joint is characterized by being made of stainless steel or copper.

Further, the motor operated valve of the present invention is
The valve chest has an inner wall parallel to the central axis of the valve body.
Further, the motor operated valve of the present invention is
wherein the valve chamber has an opening on the rotor side and the inner wall rising from the bottom side of the valve chamber;
The inner wall is parallel to the central axis of the valve body from the bottom side to the opening.
Further, the motor operated valve of the present invention is
The receding region is chamfered to widen toward the rotor.

Further, the motor operated valve of the present invention is
The valve seat is characterized in that it has an inclined surface on the opposite side of the valve port from the seat portion, which widens in a direction away from the seat portion.
Further, the motor operated valve of the present invention is
The inclined surface has an inclination angle of 45° or more with respect to the central axis of the valve body.

Further, the motor operated valve of the present invention is
the valve seat has an inclined surface on a side opposite to the seat portion of the valve port that widens in a direction away from the seat portion;
The inclined surface has an inclination angle with respect to the central axis of the valve body that is larger than the chamfer angle of the receding area.

Further, the motor operated valve of the present invention is
The largest inner diameter of the inclined surface is larger than the outer diameter of the cylindrical rod portion of the valve body.
Further, the motor operated valve of the present invention is
It is characterized by further comprising a screw feeding mechanism comprising a female screw member fixed to the valve main body and a male screw member axially moving integrally with the rotor.

Further, the motor operated valve of the present invention is
The valve body
Further comprising a third taper located ahead of the second taper,
The second taper is formed continuously with the first taper.

Further, the motor operated valve of the present invention is
The taper angle of the tapered surface of the third taper with respect to the central axis of the valve body is smaller than the taper angle of the tapered surface of the first taper with respect to the central axis of the valve body.

According to the invention of the present invention, it is possible to provide an electrically operated valve that can accurately control a minute flow rate in a low opening range.

1 is a cross-sectional view of an electrically operated valve according to an embodiment; FIG. 1 is an enlarged cross-sectional view of a main part of an electrically operated valve according to an embodiment; FIG. 7 is a graph showing flow rate characteristics in a low opening range of the motor-operated valve according to the embodiment; FIG. 11 is an enlarged cross-sectional view of a main part of a modification of the motor-operated valve according to the embodiment; FIG. 11 is an enlarged cross-sectional view of a main part of a modification of the motor-operated valve according to the embodiment; FIG. 11 is an enlarged cross-sectional view of a main part of a modification of the motor-operated valve according to the embodiment; FIG. 10 is a cross-sectional view of a conventional electric valve; FIG. 4 is an enlarged cross-sectional view of a main part of a conventional motor-operated valve, and a graph showing flow rate characteristics in a low opening range. FIG. 4 is an enlarged cross-sectional view of a main part of a virtual electric valve; FIG. 4 is an enlarged cross-sectional view of a main part of a virtual motor-operated valve, and a graph showing flow rate characteristics in a low opening range. FIG. 4 is an enlarged cross-sectional view of a main part of a virtual motor-operated valve, and a graph showing flow rate characteristics in a low opening range.

A motor-operated valve according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an electrically operated valve 2 according to an embodiment. In this specification, the terms "upper" and "lower" are defined in the state shown in FIG. That is, the rotor 4 is positioned above the valve body 17 . Moreover, the "height" in this specification is also defined in the state of FIG. That is, "height" indicates the length in the vertical direction in FIG.

In the electric valve 2, the valve body 30 is integrally connected by welding or the like to the lower opening side of the case 60 which is made of a non-magnetic material and has a cylindrical cup shape.

Here, the valve body 30 is made of metal such as stainless steel and has a valve chamber 11 therein. A first pipe joint 12 made of stainless steel, copper, or the like, which directly communicates with the valve chamber 11 , is fixedly attached to the valve body 30 . Furthermore, a valve seat member 30A in which a valve port 16 having a circular cross section is formed is provided inside the lower portion of the valve body 30. As shown in FIG. A second pipe joint 15 made of stainless steel, copper, or the like, which communicates with the valve chamber 11 via the valve port 16, is fixedly attached to the valve seat member 30A.

A rotatable rotor 4 is accommodated in the inner circumference of the case 60, and a valve shaft 41 is arranged at the axial center portion of the rotor 4 via a bush member (not shown). The valve shaft 41 and the rotor 4 coupled by a bushing member move integrally in the vertical direction while rotating. A male screw 41a is formed on the outer peripheral surface of the valve shaft 41 near the intermediate portion. In this embodiment, the valve shaft 41 functions as a male screw member.

A stator composed of a yoke, a bobbin, a coil, and the like (not shown) is arranged around the outer periphery of the case 60, and the rotor 4 and the stator constitute a stepping motor.

A guide support 52 is fixed to the ceiling surface of the case 60 . The guide support member 52 has a cylindrical portion 53 and an umbrella-shaped portion 54 formed on the upper end side of the cylindrical portion 53, and in this embodiment, the whole is integrally formed by press working. The umbrella-like portion 54 is molded in substantially the same shape as the inside of the top portion of the case 60 .

A cylindrical member 65 that also serves as a guide for the valve shaft 41 is fitted in the cylindrical portion 53 of the guide support 52 . The tubular member 65 is made of a lubricating material such as metal or synthetic resin or a surface-treated member, and holds the valve shaft 41 rotatably.

Below the valve shaft 41 , a valve shaft holder 6 that forms a threaded engagement A with the valve shaft 41 as will be described later and has a function of suppressing inclination of the valve shaft 41 is attached to the valve body 30 . It is relatively non-rotatably fixed.

The valve stem holder 6 is fixed to the valve body 30 by welding or the like, and a through hole 6h is formed inside the valve stem holder 6 . A female thread 6d is formed downward from the upper opening 6g of the valve shaft holder 6 to a predetermined depth. Therefore, in this embodiment, the valve stem holder 6 functions as a female screw member. A male thread 41a formed on the outer periphery of the valve stem 41 and a female thread 6d formed on the inner periphery of the valve stem holder 6 form a threaded engagement A shown in FIG.

A tubular valve guide 18 is arranged below the valve shaft 41 so as to be slidable in the through hole 6 h of the valve shaft holder 6 . The valve guide 18 is bent at a substantially right angle on the side of the ceiling portion 21 by press molding. A through hole 18 a is formed in the ceiling portion 21 . A flange portion 41b is further formed below the valve shaft 41. As shown in FIG.

Here, the valve shaft 41 is inserted loosely through the through hole 18a of the valve guide 18 so as to be rotatable with respect to the valve guide 18 and displaceable in the radial direction. It is positioned within the valve guide 18 so as to be rotatable relative to the guide 18 and radially displaceable. Further, the valve shaft 41 is inserted through the through hole 18a, and the upper surface of the collar portion 41b is arranged so as to face the ceiling portion 21 of the valve guide 18. As shown in FIG. It should be noted that the valve stem 41 is prevented from slipping out by the collar portion 41b having a diameter larger than that of the through hole 18a of the valve guide 18. As shown in FIG.

Since the valve shaft 41 and the valve guide 18 are movable relative to each other in the radial direction, the valve shaft holder 6 and the valve shaft 41 are not required to have a very high degree of concentric mounting accuracy. Concentricity with the valve body 17 is obtained.

Between the ceiling portion 21 of the valve guide 18 and the flange portion 41b of the valve shaft 41, a washer (not shown) having a through hole formed in the center thereof is installed. The washer is preferably a metal washer with a highly lubricious surface, a highly lubricating resin washer such as fluororesin, or a highly lubricious resin-coated metal washer.

Further, a compressed valve spring 27 and a spring retainer 35 are housed within the valve guide 18 .

The valve body 17 is made of stainless steel, brass, or the like, and has a cylindrical rod-shaped needle portion 17n, a first taper 17a, a second taper 17b, and a third taper 17c. The central axis of the valve body 17 is arranged so as to overlap the central axis L of the electric valve 2 .

FIG. 2 is an enlarged cross-sectional view of the essential parts that affect the flow rate characteristics of the motor-operated valve 2. As shown in FIG. As shown in FIG. 2, the valve seat member 30A is formed with a valve seat top surface 30A1, a recessed area 99, a valve port 16, an inclined surface 30A2, an edge portion 19a, an upper edge portion 16a, and a lower edge portion 16b. .

The valve seat top surface 30A1 is a flat surface directly in contact with the valve chamber 11 on the upper side (rotor 4 side) of the valve seat member 30A. A retracted region 99 is a portion located between the valve seat top surface 30A1 and the valve port 16 and retracted from the valve body 17 side. In this embodiment, the receding region 99 is formed with a chamfer 19 that is an upwardly widening inclined surface.

The valve port 16 is the part that directly affects the flow rate determination, as will be explained later. The inner peripheral surface of this valve port 16 is arranged so as to be parallel to the central axis L of the motor operated valve 2 .

The inclined surface 30A2 is located below the valve port 16 and is formed so that the inner diameter of the valve seat member 30A increases downward.

The edge portion 19a is a portion forming the upper edge of the chamfer 19, and constitutes the boundary between the valve seat top surface 30A1 and the chamfer 19. As shown in FIG. In the valve closed state, the first taper 17a is seated on the valve seat member 30A using the edge 19a as a seating portion.

The upper edge 16 a serves as the upper edge of the valve port 16 and the lower edge of the chamfer 19 , forming a boundary between the chamfer 19 and the valve port 16 . The lower edge portion 16b forms the lower edge of the valve port 16, and constitutes the boundary between the valve port 16 and the inclined surface 30A2. That is, the valve port 16 is formed between the upper edge 16a and the lower edge 16b.

The taper angle θ2 of the first taper 17a of the valve body 17 (the angle of the tapered surface with respect to the central axis of the valve body 17) corresponds to the inclination angle θ1 of the chamfer 19 (the inclination of the surface of the chamfer 19 with respect to the central axis L of the electric valve 2 angle) (θ1<θ2). Therefore, between the first taper 17a and the chamfer 19, when the first taper 17a is in contact with the edge portion 19a, a space 87 having a width wider than the width of the clearance 66, which will be described later, is formed.

As a result, it is possible to prevent the corner R59 formed at the boundary between the first taper 17a and the second taper 17b from being seated on the valve seat member 30A. It is possible to prevent the flow characteristics of the motor-operated valves 2 from differing at the time of rising under the influence of . Here, the corner R59 is a portion where variations in size, shape, etc. are particularly likely to occur during processing. Further, it is possible to prevent the valve body 17 from biting into the valve port 16 when the second taper 17b is seated on the valve seat member 30A.

The inclination angle θ1 is preferably 10° or more and 75° or less, and the taper angle θ2 is preferably 12.5° or more and 77.5° or less.

The corner R59 is positioned within a range where the chamfer 19 is formed in the axial direction when the valve is closed. Specifically, it is formed at a position within the range of the height H1 of the chamfer 19 in FIG.

Also, the taper angle of the second taper 17b is much smaller than the taper angle of the first taper 17a, and the outer diameter of the second taper 17b is formed to slightly decrease downward. The taper angle of the second taper 17b is preferably 1.5° or more and 10° or less with respect to the central axis L of the electric valve 2 .

Here, as described above, the third taper 17c is further formed below the second taper 17b. In the electric valve 2 according to this embodiment, the flow rate is mainly controlled by the second taper 17b and the third taper 17c formed below the first taper 17a seated on the valve seat member 30A.

Also, the height H2 of the second taper 17b is formed to be higher than the height H1 of the chamfer 19 (H1<H2). Therefore, in the motor operated valve 2 according to the present embodiment, the flow rate can be controlled in a wide range corresponding to the height H2 of the second taper 17b.

Also, the taper angle of the third taper 17c is much smaller than the taper angle θ2 of the first taper 17a, but larger than the taper angle of the second taper 17b. Here, the outer diameter of the third taper 17c is tapered so as to decrease downward.

Here, FIG. 3 is a graph showing the relationship between the amount of applied pulse and the change in flow rate. In FIG. 3, the horizontal axis of the graph represents the applied amount of pulses applied to the stepping motor to move the valve body 17, and the vertical axis of the graph represents the flow rate. The origin of the graph represents the valve closed state at 0 pulse. A broken line C in the drawing represents the change in flow rate when the valve element 17 is used. In addition, in the figure, as a contrast with the polygonal line C, a polygonal line B is shown that represents the change in the flow rate when the valve body 114' in which the second taper 17b is not formed is used as shown in FIG. .

As shown in FIG. 3, when pulses are applied to the stepping motor of the motor-operated valve 2, first, the amount of pulse applied to the motor-operated valve 2 reaches the valve opening point, and the valve body 17 begins to rise. The 1 taper 17a is separated from the upper edge 19a of the chamfer 19 which is the seating portion. Here, the flow rate is determined by the minimum width of the gap created between the valve port 16 and the valve body 17 . Therefore, the flow rate at the time of rising immediately after the first taper 17a separates from the edge 19a is determined by the gap between the first taper 17a and the edge 19a, which is the minimum width at the beginning. The flow rate in this flow rate region 61 rises sharply, albeit temporarily.

As the valve body 17 rises further, the clearance 66 between the second taper 17b and the valve port 16 becomes narrower than the gap between the first taper 17a and the rim 19a, and the clearance 66 becomes closer to the valve body 17 and the valve port. 16 is the minimum width of the gap. Therefore, the width of the clearance 66 determines the flow rate region 62 in the low opening region until the second taper 17 b passes through the valve port 16 . Here, since the flow rate in the flow rate region 62 is adjusted by the second taper 17b having an extremely small taper angle, the degree of increase is suppressed and rises gently as the second taper 17b rises and the clearance 66 widens.

In addition, since the height H2 of the second taper 17b is formed to be higher than the height H1 of the chamfer 19 (H1<H2), a rapid increase in the flow rate region 61 at the time of rising is reliably suppressed. can do. Moreover, the width of the clearance 66 is preferably 1 μm or more and 30 μm or less.

According to the electric valve 2 according to this embodiment, the function of the first taper 17a is limited to the seating function as much as possible, and the second taper 17b is mainly used to control the flow rate. It is possible to accurately control the flow rate. Further, by setting the taper angle θ2 of the first taper 17a to be larger than the inclination angle θ1 of the chamfer 19 (θ1<θ2), the boundary between the first taper 17a and the second taper 17b is the valve port 16. Since it is possible to avoid seating on the valve body 17 , it is possible to prevent the flow characteristics at the time of rising from being affected by variations in processing for each valve body 17 and different for each motor operated valve 2 .

In this embodiment, the case where the inner peripheral surface of the valve port 16 is parallel to the central axis L of the motor-operated valve 2 is described as an example, but the inner diameter of the valve port 16 increases downward. It may be formed so as to become (spread). In this case, the upper edge 16a of the valve port 16 always comes close to the second taper 17b or the third taper 17c when the valve body 17 is raised or lowered, so the flow rate control of the flow rate region 62 shown in FIG. is performed by the upper edge 16a. When the valve body 17 rises, the clearance 66 between the upper edge 16a of the valve port 16 and the second taper 17b or the third taper 17c gradually increases, increasing the flow rate.

Further, in the above-described embodiment, the case where the chamfer 19 is formed on the upper side of the valve port 16 as the recessed region 99 is taken as an example, but the recessed region 99 may be a notch. For example, as shown in FIG. 4 , a notch 79 with an L-shaped cross section may be formed on the upper side of the valve port 16 . Here, the notch 79 is formed with an edge portion 79a, a wall portion 79c, a floor portion 79d, and an upper edge portion 16a. The notch 79 forms an annular notch on the upper side of the valve seat member 30A.

The edge portion 79a forms the upper edge of the wall portion 79c and forms a boundary between the valve seat top surface 30A1 and the notch 79. As shown in FIG. In the valve closed state, the first taper 17a is seated using the edge 79a of the notch 79 as a seat. Between the first taper 17a and the chamfer 19, a width wider than the width of the clearance 66 is provided between the first taper 17a and the notch 79 when the first taper 17a is in contact with the edge 79a. A space 87 is configured.

The wall portion 79c is a side wall that defines the outer periphery of the notch 79 and is arranged parallel to the central axis L of the motor-operated valve 2 . Further, the floor portion 79 d is a portion that defines the bottom surface of the notch 79 and is perpendicular to the central axis L of the motor-operated valve 2 . Note that the wall portion 79c does not have to be strictly parallel to the central axis L, and may be slightly inclined. Similarly, the floor 79d does not need to be strictly perpendicular to the central axis L and may be slightly inclined.

The upper edge portion 16 a forms the upper edge of the valve port 16 and forms the edge of the floor portion 79 d on the valve body 17 side, and forms a boundary between the notch 79 and the valve port 16 .

This also prevents the boundary portion between the first taper 17a and the second taper 17b from being seated on the valve port 16, and prevents variations in the flow rate characteristics for each motor-operated valve 2 during startup. In addition, the second taper 17b can accurately control minute flow rates in the low opening range. Further, by forming the height H2 of the second taper 17b to be higher than the height H3 of the notch 79 (H3<H2), the flow rate can be controlled in a wide range corresponding to the height H2 of the second taper 17b. It can be performed.

Further, in the above embodiment, as shown in FIG. 5, a constriction 89 may be provided between the first taper 17a and the second taper 17b. In this case, since the boundary portion between the first taper 17a and the second taper 17b is recessed from the surface of the valve body 17, when the first taper 17a is seated on the valve seat member 30A, the first taper 17a and the valve A space 87 wider than the width of the clearance 66 is formed between the ports 16 . This also prevents the boundary portion between the first taper 17a and the second taper 17b from being seated on the valve port 16, and prevents variations in the flow rate characteristics for each motor-operated valve 2 during startup. In addition, the second taper 17b can accurately control minute flow rates in the low opening range.

In the above-described embodiment, the second taper 17b has an extremely small taper angle that is substantially parallel to the central axis L. However, as shown in FIG. 17b may have a predetermined taper angle α. Even in this case, the upper edge 16a of the valve port 16 always comes close to the second taper 17b or the third taper 17c when the valve body 17 moves up or down. done by When the valve body 17 rises, the clearance 66 between the upper edge 16a of the valve port 16 and the second taper 17b or the third taper 17c gradually increases, increasing the flow rate.

Note that the taper angle α shown in FIG. 6 is preferably an angle between 1° and 30°.

Further, in the above embodiment, the case where the valve body 17 has the third taper 17c has been described as an example, but the valve body 17 does not necessarily have to have the third taper 17c. Moreover, in the above-described embodiment, the valve body 17 may have a further taper in addition to the first taper 17a, the second taper 17b, and the third taper 17c.

Also, the motor-operated valve 2 of the present embodiment is used, for example, as an electronic expansion valve provided between a condenser and an evaporator of a refrigeration cycle system.

2 Electric valve 4 Rotor 6 Valve shaft holder 6d Female thread 16 Valve port 16a Upper edge 16b Lower edge 17 Valve element 17a First taper 17b Second taper 17c Third taper 19 Chamfer 19a Edge 30A Valve seat member 66 Clearance 79 Notch 79a Edge 79c Wall 79d Floor 89 Constriction 87 Space 99 Retraction area

Claims (19)

An electric motor that converts the rotary motion of the rotor into linear motion by threading the male and female screw members, and axially moves the stainless steel valve body housed in the valve body based on this linear motion. being a valve,
A stainless steel valve seat having a seating portion on which the valve body is seated in a valve closed state and a valve port into which the valve body is inserted,
the valve port has an inner peripheral surface parallel to the central axis of the motor operated valve,
A recessed area recessed from the valve body side is formed on the rotor side of the valve port,
The seating portion is a rotor-side edge of the recessed region that is a boundary between the recessed region and the top surface of the valve seat,
The valve body
a first taper that abuts against the seating portion in the valve closed state;
a second taper located ahead of the first taper and surrounded by the inner peripheral surface in the valve closed state,
the first taper of the valve body abuts against the edge portion in the valve closed state;
In a state in which the first taper is in contact with the seat portion, a space having a width wider than the width of the clearance formed between the valve port and the second taper is formed between the seat portion and the clearance. is formed in
A motor-operated valve, wherein the gap between the inner peripheral surface of the valve port and the second taper is the smallest in the gap between the inner peripheral surface of the valve port and the valve body. The valve body is provided with a cylindrical rod portion at a position closer to the rotor than the first taper, and the axial length of the cylindrical rod portion is larger than the outer diameter of the cylindrical rod portion. The motor operated valve according to claim 1. 3. The motor-operated valve according to claim 1, wherein the valve body has no taper on the side opposite to the second taper from the upper end of the first taper in the central axis direction. . The electrically operated valve according to any one of claims 1 to 3, wherein a valve chamber is provided inside the valve main body. 5. The motor-operated valve according to claim 4, wherein the valve body has a first pipe joint that communicates with the valve chamber. 6. The motor-operated valve according to claim 5, wherein the lower end of the inner surface of the first pipe joint is positioned higher than the position where the first taper and the seating portion abut when the valve is closed. 7. The motor-operated valve according to claim 5, wherein said first pipe joint is made of stainless steel or copper. 8. The motor-operated valve according to claim 5, wherein the end of the first pipe joint on the valve chamber side protrudes into the valve chamber. the valve seat includes a second pipe joint that communicates with the valve chamber through the valve port;
9. The electrically operated valve according to any one of claims 4 to 8, wherein said second pipe joint is made of stainless steel or copper. 10. The electrically operated valve according to any one of claims 4 to 9, wherein the valve chamber has an inner wall parallel to the central axis of the valve body. wherein the valve chamber has an opening on the rotor side and the inner wall rising from the bottom side of the valve chamber;
11. The electrically operated valve according to claim 10, wherein the inner wall is parallel to the central axis of the valve body from the bottom side to the opening. 12. The electrically operated valve according to any one of claims 1 to 11, wherein the receding area is a chamfer that widens toward the rotor. 13. The valve seat according to any one of claims 1 to 12, wherein the valve seat has an inclined surface on the side opposite to the seat portion of the valve port that widens in a direction away from the seat portion. electric valve. 14. The motor-operated valve according to claim 13, wherein the inclined surface has an inclination angle of 45[deg.] or more with respect to the central axis of the valve body. the valve seat has an inclined surface on a side opposite to the seat portion of the valve port that widens in a direction away from the seat portion;
13. The motor-operated valve according to claim 12, wherein the inclined surface has an inclination angle with respect to the central axis of the valve body that is larger than a chamfering angle of the receding area. 16. The motor-operated valve according to any one of claims 13 to 15, wherein the largest inner diameter of the inclined surface is larger than the outer diameter of the cylindrical rod portion of the valve body. 17. The screw feeding mechanism according to any one of claims 1 to 16, further comprising a female screw member fixed to said valve body and a male screw member axially moving integrally with said rotor. The electric valve described in 1. The valve body
Further comprising a third taper located ahead of the second taper,
18. The motor-operated valve according to any one of claims 1 to 17, wherein the second taper is formed continuously with the first taper. The taper angle of the tapered surface of the third taper with respect to the central axis of the valve body is smaller than the taper angle of the tapered surface of the first taper with respect to the central axis of the valve body. electric valve.

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