CN113108071A

CN113108071A - Electric valve

Info

Publication number: CN113108071A
Application number: CN202110006820.1A
Authority: CN
Inventors: 矢泽将志; 大鹿真一郎; 猪野泰利
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2020-01-10
Filing date: 2021-01-05
Publication date: 2021-07-13
Also published as: JP2021110401A; JP7150345B2

Abstract

Provided is an electrically operated valve which can control a fluid flowing in the same direction at a small flow rate and a fluid flowing in the same direction at a large flow rate and which can easily adjust the position of a valve shaft. In the motor-operated valve, the lift amount of the valve shaft is configured to have a first range in which the flow path cross-sectional area between the flow path adjustment portion and the small-diameter valve port is changed in a state in which the movable valve seat body is seated on the large-diameter valve port, and a second range in which the flow path cross-sectional area between the movable valve seat body and the large-diameter valve port is changed in a state in which the movable valve seat body is locked to the engagement portion, a predetermined gap is formed between the flow path adjustment portion and the small-diameter valve port when the flow path adjustment portion in the first range is located at a lower end position that is most moved toward the small-diameter valve port side, a pipe for fluid supply is connected to the first valve chamber, and a communication hole that communicates the first valve chamber with the second valve.

Description

Electric valve

Technical Field

The present invention relates to an electrically operated valve.

Background

Conventionally, for example, an electrically operated valve has been used as a device which is disposed in a piping system of a fluid and performs opening and closing of a flow path of the fluid and flow rate control. In such an electrically operated valve, the valve body is driven by a drive source such as a stepping motor attached to the valve body in order to accurately control the flow rate.

Patent document 1 discloses the following technique: in an electrically operated valve capable of flowing a small flow rate of fluid in a forward direction and a large flow rate of fluid in a reverse direction, a movable valve seat body functions as a floating type check valve body.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2013-241958

Technical problem to be solved by the invention

Here, the motor-operated valve of patent document 1 has a problem in that it cannot perform fluid control of a small flow rate and fluid control of a large flow rate with respect to a fluid flowing in the same direction in terms of its structure.

In addition, in particular, for fluid control with a small flow rate with high accuracy, positioning of the valve shaft is important, but in the motor-operated valve of patent document 1, the influence of manufacturing errors and assembly errors of parts is large, and there is a problem that it takes time to perform positioning adjustment. In addition, there is a demand for suppressing noise in an electrically operated valve for controlling the flow of a refrigerant in which a liquid and a gas are mixed.

Disclosure of Invention

An object of the present invention is to provide an electrically operated valve that can perform fluid control of a small flow rate and fluid control of a large flow rate with respect to fluid flowing in the same direction and that can easily perform positioning adjustment of a valve shaft.

Means for solving the problems

The motor-operated valve of the invention comprises:

a valve main body provided with a first valve chamber and a large-diameter valve port;

a valve shaft inserted into the first valve chamber, and provided with a flow path adjustment portion, an engagement portion, and a step portion;

a valve shaft driving unit capable of changing a lift amount by displacing the valve shaft in a direction in which the valve shaft is brought into contact with and separated from the large-diameter valve port; and

a movable valve seat body that is disposed so as to be movable in the first valve chamber in a displacement direction of the valve shaft, and that includes a second valve chamber and a small-diameter valve port connected to the second valve chamber,

the electrically operated valve is configured to have, within a variation range of the lift amount of the valve shaft, a first range in which a flow passage cross-sectional area between the flow passage adjustment portion and the small-diameter valve port is varied in a state in which the movable valve seat body is seated on the large-diameter valve port, and a second range in which the flow passage cross-sectional area between the movable valve seat body and the large-diameter valve port is varied in a state in which the movable valve seat body is engaged with the engagement portion,

in the first range, when the flow path adjusting portion is located at a lower end position that is most moved toward the small-diameter valve port, a predetermined clearance is provided between the flow path adjusting portion and the small-diameter valve port,

a pipe for supplying fluid is connected to the first valve chamber,

the communication hole for communicating the first valve chamber and the second valve chamber is provided above an upper end of an inner periphery of the pipe.

Effects of the invention

According to the electrically operated valve of the present invention, it is possible to provide an electrically operated valve which can perform fluid control of a small flow rate and fluid control of a large flow rate with respect to fluid flowing in the same direction and which can easily perform positioning adjustment of a valve shaft.

Drawings

Fig. 1 is a longitudinal sectional view showing an electrically operated valve according to a first embodiment.

Fig. 2 is a diagram showing flow rate measurement of the motor-operated valve according to the present embodiment, in which the horizontal axis shows the number of control pulses applied to rotate the rotor 30, and the vertical axis shows the amount of refrigerant flowing from the supply-side round tube T1 to the discharge-side round tube T2.

Fig. 3 is an enlarged cross-sectional view showing the periphery of the valve chamber of the motor-operated valve shown in fig. 1, and shows a state in which the valve shaft is located at a position corresponding to point a in fig. 2.

Fig. 4 is an enlarged view showing the periphery of the valve portion, and shows a state in which the valve shaft is located at a position corresponding to point a in fig. 2.

Fig. 5 is an enlarged cross-sectional view showing the periphery of the valve chamber of the motor-operated valve shown in fig. 1, and shows a state in which the valve shaft is located at a position corresponding to point B in fig. 2.

Fig. 6 is an enlarged view showing the periphery of the valve portion, and shows a state in which the valve shaft is located at a position corresponding to point B in fig. 2.

Fig. 7 is an enlarged cross-sectional view showing the periphery of the valve chamber of the motor-operated valve shown in fig. 1, and shows a state in which the valve shaft is located at a position corresponding to point C in fig. 2.

Fig. 8 is an enlarged view showing the periphery of the valve portion, and shows a state in which the valve shaft is located at a position corresponding to point C in fig. 2.

Fig. 9 is an enlarged cross-sectional view of the periphery of the valve chamber of the motor-operated valve shown in fig. 1, and shows a state in which the valve shaft is located at a position corresponding to point D in fig. 2.

Fig. 10 is an enlarged cross-sectional view showing the periphery of the valve chamber in the motor-operated valve according to the second embodiment, and shows a state in which the valve shaft is located at a position corresponding to point a' in fig. 2.

Fig. 11 is a longitudinal sectional view showing an electrically operated valve of the third embodiment.

Fig. 12 is an enlarged cross-sectional view showing the periphery of a valve chamber of the motor-operated valve shown in fig. 11.

Fig. 13 is a longitudinal sectional view showing an electrically operated valve of the fourth embodiment.

Fig. 14 is an enlarged cross-sectional view showing the periphery of a valve chamber of the motor-operated valve shown in fig. 13.

Fig. 15 is a longitudinal sectional view showing an electrically operated valve of the fifth embodiment.

Fig. 16 is an enlarged cross-sectional view showing the periphery of a valve chamber of the motor-operated valve shown in fig. 15.

Fig. 17 is an enlarged cross-sectional view showing the periphery of a valve chamber of the motor-operated valve according to the sixth embodiment.

Description of the symbols

10. 10B, 10C, 10D electric valve

20. 20B, 20C valve body

21 valve chamber

24. 24A, 24C, 24E valve shaft

25 fixed thread part (external thread part)

26 guide bush

27 lower stop body

30 rotor

31 moving screw thread part (internal screw thread part)

32 valve shaft holder

33 push nut

34 compression coil spring

35 return spring

36 support ring

37 upper stop body

40 casing

41 annular plate

50 stator

60. 60C valve seat component

70. 70B, 70C, 70D, 70E moving valve seat body

VS1 first valve chamber

VS2 second valve chamber

VS3 third valve chamber

Detailed Description

Hereinafter, embodiments of the motor-operated valve according to the present invention will be described with reference to the drawings. In the present specification, the direction from the rotor toward the valve seat is defined as downward, and the reverse direction is defined as upward. The electric valve preferably uses the lower side as the direction of gravity.

[ first embodiment ]

Fig. 1 is a longitudinal sectional view showing an electric valve 10 according to a first embodiment. An electrically operated valve 10 for controlling the flow rate of a refrigerant (fluid) in a refrigeration cycle or the like of an automobile or the like includes: the valve includes a valve seat member 60, a valve body 20 to which the valve seat member 60 is attached, a housing 40 attached to the valve body 20 and incorporating a rotor 30 that drives a valve shaft 24, and a stator 50 externally fitted to the housing 40 and driving the rotor 30 to rotate. The axis of the motor-operated valve 10 is denoted by L.

A pair of bobbins 52, a stator coil 53, and a yoke 51 surrounding the pair of bobbins 52 and the stator coil 53 are disposed on the outer periphery of the cylindrical portion of the housing 40, and the outer periphery is covered with a resin mold cover 56 to form the stator 50. In the present embodiment, resin mold cover 56 covers the upper portion including case 40, but may cover only the periphery of yoke 51. The rotor 30 and the stator 50 constitute a stepping motor.

Stator coil 53 is connected to an external power supply circuit (not shown) via substrate CB and connector CN.

The case 40 is formed of a nonmagnetic metal such as stainless steel, and has a bottomed cylindrical shape. The open lower end of the housing 40 is welded to the upper end of the valve main body 20 as described later and fixed.

The substantially cylindrical valve shaft 24 is formed of stainless steel, brass, or the like, and is formed by coaxially and continuously providing a first shaft portion 24a on the upper end side, a second shaft portion 24b having a larger diameter than the first shaft portion 24a, a third shaft portion 24c having a smaller diameter than the second shaft portion 24b, a fourth shaft portion 24d having a smaller diameter than the third shaft portion 24c, and a valve portion 24e on the lower end side. The valve portion 24e as the flow path adjusting portion has a tapered shape with a diameter decreasing toward the distal end side. An upper step portion (step portion) 24f is formed between the second shaft portion 24b and the third shaft portion 24c, and a lower step portion 24g is formed between the third shaft portion 24c and the fourth shaft portion 24 d.

The substantially cylindrical valve shaft holder 32 is disposed in the housing 40 so as to accommodate the upper end side of the valve shaft 24. The upper end of the valve shaft holder 32 and the upper end of the first shaft portion 24a of the valve shaft 24 are joined by a push nut 33 that is press-fitted and fixed.

A return spring 35 composed of a compression coil spring is attached along the outer periphery of the push nut 33. The return spring 35 has a function of coming into contact with the top inner surface of the housing 40 and biasing the same so as to restore the screwing of the fixed screw portion 25 and the moving screw portion 31 when the fixed screw portion 25 of the guide bush 26 and the moving screw portion 31 of the valve shaft holder 32 are unscrewed, which will be described later.

The rotor 30, which is arranged at a clearance relative to the housing 40, is coupled to the valve shaft holder 32 via a bearing ring 36. More specifically, the support ring 36 is formed of a brass metal ring that is fitted when the rotor 30 is molded, and the rotor 30, the support ring 36, and the valve shaft holder 32 are coupled by fitting an upper projection of the valve shaft holder 32 into an inner peripheral hole portion of the support ring 36 and caulking and fixing an outer periphery of the upper projection.

An upper stopper 37 constituting a stopper mechanism is fixed to the outer periphery of the valve shaft holder 32. The upper stopper 37 is made of an annular resin, and a plate-shaped upper stopper piece 37a is provided to protrude downward.

The cylindrical guide bush 26 is disposed between the valve shaft holder 32 and the valve shaft 24. The lower end of the guide bush 26 is press-fitted to the inner periphery of a retainer 220 described later. A lower stopper 27 constituting the other stopper mechanism is fixed to the outer periphery of the guide bush 26. The lower stopper 27 is made of an annular resin, and a plate-shaped lower stopper piece 27a is provided so as to protrude upward, and the lower stopper piece 27a can be engaged with the upper stopper piece 37 a.

The lower stopper 27 is fixed to a spiral groove portion 26a formed on the outer periphery of the guide bush 26 by injection molding, and the upper stopper 37 is fixed to a spiral groove portion 32b formed on the outer periphery of the valve shaft holder 32 by injection molding.

A moving screw portion 31 is formed on the inner surface of the valve shaft holder 32, and the moving screw portion 31 is screwed to a fixed screw portion 25 formed on the outer periphery of the guide bush 26. The screw feed mechanism including the moving screw portion 31 and the fixed screw portion 25 and the rotor 30 constitute a valve shaft driving portion that moves the valve shaft 24 forward and backward in the direction of the axis L.

The valve shaft 24 is inserted so as to be movable up and down along the axis L of the valve shaft holder 32, and is biased downward by a compression coil spring 34 that is compressively attached to the inside of the valve shaft holder 32. A pressure equalizing hole 32a is formed in a side surface of the guide bush 26, and the pressure equalizing hole 32a equalizes the pressure in the valve chamber 21 and the housing 40.

The valve main body 20 has: a tubular main body 210 formed of a metal straight pipe having a uniform wall thickness and outer diameter, a retainer 220 press-fitted into the inner periphery of the tubular main body 210 on the upper end side, and a valve seat member 60. The holder 220 as a guide portion has a hollow cylindrical portion 221 and a partition wall 222 formed in the middle of the inner circumference of the hollow cylindrical portion 221. The hollow cylindrical portion 221 has an enlarged diameter portion 223 enlarged in diameter near the upper end. The diameter-enlarged portion 223 is fitted to a thin portion 212 formed at the upper end of the tubular body 210, thereby positioning the tubular body 210 and the holder 220 in the direction of the axis L. The enlarged diameter portion 223 projects at its upper end in a state of being fitted to the tubular body 210, and functions as an engagement guide when engaged with the housing 40 described later.

The guide bush 26 is press-fitted into the inner periphery of the hollow cylindrical portion 221 so that the lower end of the guide bush 26 abuts against the partition wall 222. A circular hole 225 is formed in the center of the partition wall 222.

The valve seat member 60 is fixed to the lower end of the tubular body 210 by brazing. A flange portion 64 is formed at the lower end of the valve seat member 60, the flange portion 64 has an outer diameter larger than the inner diameter of the tubular main body 210, and the positioning of the valve seat member 60 with respect to the tubular main body 210 in the direction of the axis L can be performed by bringing the flange portion 64 into contact with the lower end of the tubular main body 210.

The valve seat member 60 having a hollow cylindrical shape has a thin cylindrical portion 61 whose upper end is reduced in diameter, and a tapered valve seat (large diameter valve port) 62 whose diameter increases upward on the inner peripheral side of the upper end of the thin cylindrical portion 61. A projection 63 projecting annularly is formed in the middle of the inner periphery of the valve seat member 60. The upper end of the discharge side round tube T2 abuts against the lower surface of the projecting portion 63, and is fitted to the inner periphery of the seat member 60 and fixed by brazing. By setting the inner diameter of the thin cylindrical portion 61 to be larger than the inner diameter of the discharge-side circular tube T2, the maximum amount of refrigerant that can pass can be increased.

A circular hole 211 is formed in the outer periphery of the tubular body 210, and a supply side circular tube T1 is inserted into the circular hole 211. The tip end of the supply side round tube T1 having the center line O is positioned in contact with the outer periphery of the thin cylindrical portion 61 of the valve seat member 60, and in this state, the supply side round tube T1 is brazed to the tubular main body 210. A first flow path is formed in the supply side circular tube T1 communicating with the valve chamber 21, and a second flow path is formed in the discharge side circular tube T2 communicating with the valve chamber 21. The center line O of the supply side round tube T1 is orthogonal to the axis L.

In the tubular body 210, a space between the retainer 220 and the valve seat member 60 is defined as a valve chamber 21. The movable valve seat body 70 is disposed in the valve chamber 21 so as to be displaceable in the direction of the axis L. The movement valve seat body 70 has: there are a top cylindrical sleeve 71 and a disc-shaped seat 72 engaged with the lower end of the sleeve 71.

The sleeve 71 includes four lateral holes (also referred to as communication holes) 71a at equal intervals in the circumferential direction at a height position facing the supply side round tube T1, and a circular opening 71c is formed in the center of a ceiling wall (also referred to as a partition wall) 71 b.

Referring to fig. 3 described later, the seat portion 72 is provided with a disc portion 72a and a short cylindrical portion 72b having a smaller diameter than the disc portion 72a continuously, and the lower end of the sleeve 71 is press-fitted into the outer periphery of the short cylindrical portion 72b so as to abut against the upper surface of the disc portion 72 a.

A tapered seat surface 72c whose diameter decreases downward is formed on the outer periphery of the lower surface of the disk portion 72a of the seat portion 72, and the seat surface 72c is capable of seating on the valve seat 62 of the valve seat member 60. Referring to fig. 4 described later, a communication hole 72f is formed in the center of the seat portion 72, and the communication hole 72f is formed by connecting a cylindrical hole (small diameter valve port) 72d on the upper end side and a tapered hole 72e on the lower end side. By providing the tapered hole 72e having a diameter gradually increased next to the cylindrical hole 72d, the sound of refrigerant passing therethrough is reduced, and the stability of the motor-operated valve 10 is improved. Here, the cylindrical hole 72d constitutes a valve port.

The outer diameter of the sleeve 71 is preferably smaller than the minimum inner diameter of the seating surface 72c, so that the volume of the valve chamber 21 can be ensured to be large. Further, by using the cylindrical hole 72d having a relatively small diameter, the inner diameter of the sleeve 71 can be suppressed to be small, and the volume and the opening cross-sectional area of the sleeve 71 can be reduced, or the weight of parts can be reduced.

Referring to fig. 3 described later, the second shaft portion 24b of the valve shaft 24 inserted in the valve chamber 21 is inserted in the circular hole 225 of the holder 220, and the third shaft portion 24c is inserted in the circular opening 71c of the sleeve 71. In the sleeve 71, an annular member 73 as an engaging portion is press-fitted and attached so as to abut against the lower step portion 24g between the third shaft portion 24c and the fourth shaft portion 24 d. The upper end portion (the portion on the lower stepped portion 24g side) of the fourth shaft portion 24d is formed to have a larger diameter than the other fourth shaft portions 24d so that the annular member 73 can be press-fitted.

In fig. 1, an end portion of a cylindrical portion 240 is fixed to an outer periphery of a cylindrical body 210 of a valve body 20 by welding or brazing, and the cylindrical portion 240 is formed into a cylindrical shape by press-forming a stainless steel plate (SUS plate). The cylindrical portion 240 is engaged with a plate spring 241 extending from the stator 50 side, whereby the valve main body 20 is prevented from rotating relative to the stator 50.

(Assembly of valve body)

First, the valve seat member 60 is inserted until the flange portion 64 abuts against the lower end of the tubular body 210, and the discharge side round tube T2 is inserted into the lower end side opening of the valve seat member 60. On the other hand, the supply side round tube T1 is inserted through the round hole 211 of the tubular body 210 until the tip end of the supply side round tube T1 hits the valve seat member 60. Thereafter, the seat member 60, the supply side round pipe T1, and the discharge side round pipe T2 are fixed integrally with the cylindrical body 210 by brazing.

Thereafter, the sleeve 71 is brought close to the valve shaft 24, and the sleeve 71 is inserted into the holder 220 so that the valve shaft 24 penetrates the circular opening 71 c.

Subsequently, the annular member 73 is press-fitted into the fourth shaft portion 24d, and abuts against the lower step portion 24 g. In this state, the short cylindrical portion 72b of the seat portion 72 is press-fitted into the lower end of the sleeve 71. The sleeve assembly constituted by the sleeve 71, the valve shaft 24, the annular member 73, and the short cylindrical portion 72b assembled in this manner is inserted into the tubular body 210 to be regulated. The sleeve 71 is slidable relative to the holder 220. Thereafter, the holder 220 is press-fitted into the cylindrical body 210 in a state where the valve shaft 24 of the sleeve assembly is inserted into the circular hole 225 of the cylindrical body 210. At this time, by reducing a portion of the outer diameter of the holder 220, the load applied during press-fitting can be reduced. The guide bush 26 is pressed into the holder 220, and the lower stopper 27a is mounted. Further, the compression coil spring 34, the valve shaft holder 32, the lower stopper 27, the rotor 30, the push nut 33, and the like are assembled to the valve shaft 24 protruding from the guide bush 26.

Further, in a state where the lower end of the case 40 is fitted to the enlarged diameter portion 223 of the holder 220 protruding from the upper end of the cylindrical body 210, the lower end of the case 40 and the upper end of the cylindrical body 210 which are butted thereto are laser-welded over the entire circumference to form a welded portion W. Thereby, the coaxiality of the housing 40 and the cylindrical body 220 is ensured, and the housing 40, the holder 220, and the cylindrical body 210 are joined at one location. Since the holder 220 is not exposed to the outside, it is advantageous for aging and the like. In addition, the stator 50, which is assembled in advance in another process, is mounted on the outer circumference of the housing 40. The assembly of the motor-operated valve 10 is completed in this manner.

According to the present embodiment, since the sleeve 71 is configured to be guided by the inner periphery of the hollow cylindrical portion 221 of the holder 220, it is not necessary to use the inner periphery of the tubular main body 210 as a guide, and the tubular main body 210 can be formed using an inexpensive pipe or the like. Further, since the outer diameter of the sleeve 71 can be made relatively small by matching the outer diameter of the sleeve 71 with the inner diameter of the hollow cylindrical portion 221, a relatively large valve chamber 21 can be formed between the sleeve 71 and the tubular main body 210, and the performance as the motor-operated valve 10 can be improved.

(operation of electric valve)

Fig. 2 is a diagram showing the flow rate measurement of the motor-operated valve 10 according to the present embodiment, in which the horizontal axis shows the number of control pulses applied to rotate the rotor 30, and the vertical axis shows the amount of refrigerant flowing from the supply-side circular tube T1 to the discharge-side circular tube T2. The control pulse number corresponds to the relative displacement amount (lift amount) of the valve shaft 24. In fig. 2, the range of the number of control pulses from the point a to the point C is set as a control range of a small flow rate (a first range in which the flow path sectional area between the fourth shaft portion 24D and the cylindrical hole 72D is changed in a state where the seat surface 72C of the moving valve seat body 70 is seated on the valve seat 62), and the range from the point C to the point D is set as a control range of a large flow rate (a second range in which the flow path sectional area between the seat surface 72C of the moving valve seat body 70 and the valve seat 62 is changed in a state where the moving valve seat body 70 is locked to the annular member 73).

The operation of the motor-operated valve 10 of the present embodiment will be described. Hereinafter, the flow passage cross-sectional area formed by the gap (first gap) between the valve shaft 24 and the cylindrical hole 72d is S1, and the flow passage cross-sectional area formed by the gap (second gap) between the seat surface 72c and the valve seat 62 is S2.

In fig. 1, when energization to the stator coil 53 of the stator 50 is performed by supplying power from the outside through the connector CN and the base plate CB to excite the stator, a rotational force is generated in the rotor 30 by the generated magnetic force, and therefore the rotor 30 and the valve shaft holder 32 are rotationally driven with respect to the guide bush 26 fixed to the valve main body 20.

Thus, the valve shaft holder 32 is displaced in the direction of the axis L thereof by the screw feed mechanism constituted by the fixed screw portion 25 of the guide bush 26 and the moving screw portion 31 of the valve shaft holder 32. When the valve shaft holder 32 is displaced downward by energizing the stator coil 53, the movable valve base body 70, which is in a state of being locked to the annular member 73 by gravity, is displaced downward together with the valve shaft holder 32. When the valve shaft holder 32 is further displaced downward, the seat surface 72c of the movable valve seat body 70 is seated on the valve seat 62 of the valve seat member 60. When the valve shaft holder 32 is further displaced downward from this state, the ring member 73 is separated from the top wall 71b, and then the upper step portion 24f of the valve shaft 24 abuts against the upper surface of the top wall 71b of the sleeve 71, and the seat surface 72c is pressed against the valve seat 62 by the elastic force of the coil spring 34, thereby blocking the flow of the refrigerant between the seat surface 72c and the valve seat 62.

On the other hand, as shown in fig. 3 and 4, in a state where the upper step portion 24f of the valve shaft 24 abuts against the upper surface of the top wall 71b of the sleeve 71, the lower end of the fourth shaft portion 24d (the upper end of the valve portion 24 e) is located within the range of the cylindrical hole 72d of the movable valve seat body 70. Here, the overlapping amount of the fourth shaft portion 24d and the cylindrical hole 72d in the axis L direction is δ. Further, the case where δ is 0mm is also included. In this way, when the fourth shaft portion 24d is located at the lower end position moved most toward the cylindrical hole 72d in the first range, a predetermined gap S3 (excluding 0 mm) is formed between the fourth shaft portion 24d and the cylindrical hole 72 d.

At this time, since the flow passage cross-sectional area S1 formed by the gap S3 between the fourth shaft portion 24d and the cylindrical hole 72d is the smallest, the refrigerant passes through the flow passage cross-sectional area S1. In other words, the gap between the fourth shaft portion 24d and the cylindrical hole 72d is not completely closed, but a minimum flow rate of refrigerant flows therebetween. More specifically, the refrigerant supplied from the supply-side round tube T1 to the valve chamber 21 enters the interior of the sleeve 71 through the transverse hole 71a of the sleeve 71, flows into the interior of the seat member 60 through between the fourth shaft portion 24d and the cylindrical hole 72d, and is discharged through the discharge-side round tube T2.

According to the present embodiment, the position in the axis L direction of the valve portion 24e with respect to the cylindrical hole 72d can be determined by abutting the upper stepped portion 24f of the valve shaft 24 against the upper surface of the ceiling wall 71b of the sleeve 71, and thus the flow rate can be accurately controlled. That is, since the deviation of the actual position of the valve portion 24e with respect to the design position of the valve portion 24e increases with the manufacturing error and the assembly error of each component, for example, in a configuration in which the positioning of the valve portion 24e is performed using a stopper or the like, the number of components involved increases, and there may be a large deviation of the actual position. In contrast, in the present embodiment, only the sleeve 71 is interposed between the seat portion 72 forming the cylindrical hole 72d and the upper stepped portion 24f, so that the cause of the deviation can be eliminated as much as possible, and the positioning of the valve portion 24e with respect to the cylindrical hole 72d can be performed with high accuracy.

In a state where the upper step portion 24f of the valve shaft 24 abuts on the upper surface of the ceiling wall 71b of the sleeve 71, the upper stopper 37 does not abut on the lower stopper 27, and the rotor 30 and the valve shaft holder 32 further rotate and descend together with the valve shaft 24 and the sleeve 71. At this time, the relative downward displacement of the valve shaft holder 32 with respect to the valve shaft 24 is absorbed by compressing the compression coil spring 34.

Thereafter, the rotor 30 further rotates, the valve shaft holder 32 descends, and the upper stopper piece 37a of the upper stopper body 37 abuts against the lower stopper piece 27a of the lower stopper body 27. Due to the abutment of the lower stopper piece 27a and the upper stopper piece 37a, the lowering of the valve shaft holder 32 is forcibly stopped even if the energization to the stator 50 is continued.

Since the stopper mechanism including the upper stopper 37 and the lower stopper 27 is disposed over the entire length of the rotor 30 in the axial direction, the rotor 30 and the valve shaft holder 32 are less greatly inclined and the operation is stable even when the stopper mechanism is operated, and then the operation can be smoothly performed even when the rotor 30 is reversely rotated.

When the stator 50 is energized in the reverse direction, the rotor 30 and the valve shaft holder 32 rotate in the opposite direction to the above direction with respect to the guide bush 26, and the valve shaft holder 32 is displaced upward by the above-described screw feed mechanism. At this time, the refrigerant pressure in the valve chamber 21 is higher than the refrigerant pressure in the discharge side round tube T2, and therefore, the moving valve seat body 70 is biased downward by this pressure difference, and the seat surface 72c of the seat portion 72 is held seated on the valve seat 62 of the valve seat member 60.

Therefore, no gap is formed between the seat surface 72c and the valve seat 62, and the refrigerant passes only between the fourth shaft portion 24d and the cylindrical hole 72 d. Therefore, as shown in fig. 5 and 6, the flow rate does not change because the flow path cross-sectional area S1 is kept at a minimum until the lower end of the fourth shaft portion 24d of the valve shaft 24 reaches the upper end of the cylindrical hole 72 d. At this time, the relationship between the number of control pulses and the flow rate is indicated by a solid line from point a to point B in fig. 2.

When the valve portion 24e of the valve shaft 24 is displaced upward from the upper end of the cylindrical hole 72d from the position shown in fig. 5 and 6, the gap between the tapered valve portion 24e and the cylindrical hole 72d changes, and the flow path cross-sectional area S1 (see fig. 8) increases. That is, the flow rate of the refrigerant passing through the flow path cross-sectional area S1 changes according to the relative displacement amount between the movement valve seat body 70 and the valve shaft 24, and therefore, a small flow rate of fluid control can be performed. At this time, the relationship between the number of control pulses and the flow rate is indicated by a solid line from point B to point C in fig. 2.

Further, when the stator 50 is continuously energized in the reverse direction, as shown in fig. 7 and 8, the annular member 73 abuts against the lower surface of the top wall 71b of the sleeve 71, and thereafter, the movable valve seat body 70 is displaced upward together so as to be lifted by the valve shaft 24. Therefore, as shown in fig. 9, the seat surface 72c of the movable valve seat body 70 is separated from the valve seat 62 of the valve seat member 60, and a relatively large flow path cross-sectional area S2 is formed by a gap between the seat surface 72c and the valve seat 62.

Further, when the reverse direction energization is continued, the flow path cross-sectional area S2 between the seat surface 72c and the valve seat 62 is enlarged according to the displacement amount of the valve shaft 24, and therefore a large flow rate of the refrigerant corresponding to the flow path cross-sectional area S2 flows.

In this state, the refrigerant flows from the supply-side circular tube T1 to the discharge-side circular tube T2 through the flow path having the flow path cross-sectional area S1 plus the flow path cross-sectional area S2, but since no relative displacement occurs between the valve portion 24e and the cylindrical hole 72d, the flow path cross-sectional area S1 (fig. 8) is constant, whereas the flow path cross-sectional area S2 changes in accordance with the amount of displacement of the valve shaft 24. Therefore, the fluid control of a large flow rate can be performed with high accuracy. When the valve shaft 24 is displaced to the maximum position, the flow path cross-sectional area S2 does not further expand, both the flow path cross-sectional area S1 and the flow path cross-sectional area S2 are constant, and the amount of refrigerant flowing from the supply-side round tube T1 to the discharge-side round tube T2 is constant. At this time, the relationship between the number of control pulses and the flow rate is indicated by a solid line from point C to point D in fig. 2.

In this way, the amount of refrigerant passing in the same direction can be adjusted by displacing the valve shaft 24 in the axial direction by the amount of rotation of the rotor 30. Since the amount of rotation of the rotor 30 is limited by the number of input pulses to the pulse motor, the refrigerant throughput can be accurately adjusted for both a small flow rate and a large flow rate.

[ second embodiment ]

Fig. 10 is an enlarged cross-sectional view showing the periphery of a valve chamber in the motor-operated valve according to the second embodiment. In the present embodiment, the valve portion and the valve port of the valve shaft have different shapes from those of the first embodiment. The valve shaft 24A is not formed with a structure corresponding to the upper step portion 24 f. Otherwise, the same components as those of the first embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

The valve portion 24Ae of the valve shaft 24A has a double-tapered shape as shown in fig. 10, and more specifically, the valve portion 24Ae has a first valve portion 24Ae1 adjacent to the fourth shaft portion 24Ad and a second valve portion 24Ae2 adjacent to the first valve portion 24Ae 1. Here, in a cross section obtained by cutting the valve shaft 24A on a plane passing through the axis L, an angle sandwiched by outer straight lines on both sides of the first valve portion 24Ae1 facing each other around the axis L is defined as a taper angle θ 1, and an angle sandwiched by outer straight lines on both sides of the second valve portion 24Ae2 facing each other around the axis L is defined as a taper angle θ 2. In the present embodiment, the taper angle θ 1 is larger than the taper angle θ 2.

The communication hole 72Af of the seat portion 72A serving as the valve port includes a small tapered portion 72Ag, a cylindrical hole 72Ad adjacent to the small tapered portion 72Ag, and a tapered hole 72Ae adjacent to the cylindrical hole 72 Ad.

According to the present embodiment, when the valve shaft 24A is displaced downward by energization of the stator coil 53 (see fig. 1), as shown in fig. 10, the first valve portion 24Ae1 is seated on the small tapered portion 72Ag, and therefore, the gap between the valve portion 24Ae and the communication hole 72Af disappears, and the refrigerant does not pass therebetween. Referring to fig. 3, as long as the seat surface 72c of the seat portion 72A is seated on the seat 62 of the seat member 60, the refrigerant does not pass therebetween, and therefore the flow of the refrigerant from the supply-side round tube T1 to the discharge-side round tube T2 is shut off.

On the other hand, when the valve shaft 24A is displaced upward by the reverse current, a gap is formed between the valve portion 24Ae and the communication hole 72Af according to the displacement amount, and therefore a small flow rate of the refrigerant corresponding to the flow path cross-sectional area flows. At this time, the relationship between the number of control pulses and the flow rate is represented by a broken line from point a' to point B and a solid line from point B to point C in fig. 2.

Further, when the reverse direction current is continued, referring to fig. 9, the annular member 73 abuts against the lower surface of the top wall 71b of the sleeve 71, and the movable valve seat body 70 is lifted by the valve shaft 24A, so that a gap is generated between the seat surface 72c of the movable valve seat body 70 and the valve seat 62 of the valve seat member 60. Thereafter, since the gap between the seat surface 72c and the valve seat 62 changes according to the displacement amount of the valve shaft 24A, a large flow rate of the refrigerant corresponding to the flow path cross-sectional area thereof flows. At this time, the relationship between the number of control pulses and the flow rate is represented by a solid line from point C to point D in fig. 2, as in the first embodiment.

Although not shown in fig. 10, a groove (notch) may be formed in the small tapered portion 72Ag of the motor-operated valve in a direction along the flow direction. Thus, in a state where the first valve portion 24Ae1 is seated on the small tapered portion 72Ag, a predetermined minute flow rate can be ensured. In addition, the grooves (notches) are preferably formed in plural.

[ third embodiment ]

Fig. 11 is a longitudinal sectional view showing a motor-operated valve 10B according to a third embodiment. Fig. 12 is an enlarged cross-sectional view showing the periphery of a valve chamber in the motor-operated valve 10B of fig. 11. In the present embodiment, the shape of the sleeve 71B for moving the valve seat body 70B is different from that of the first embodiment, but the seat portion 72 is the same as that of the first embodiment. The same components as those of the first embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

More specifically, the lateral hole (communication hole) 71Ba of the sleeve 71B is moved upward from the lateral hole of the first embodiment, and is disposed near the lower end of the holder 220. In the present embodiment, the inner peripheral lower end of the horizontal hole 71Ba is preferably located above the inner peripheral upper end of the supply-side circular tube (fluid supply pipe) T1, but the inner peripheral upper end of the horizontal hole 71Ba may be located slightly below the inner peripheral upper end of the supply-side circular tube T1.

Specifically, as shown in fig. 12, the inner peripheral lower end 71B1 of the horizontal hole 71Ba of the present embodiment is located above (in the antigravity direction in fig. 12) an extension line a extending from the inner peripheral upper end of the supply-side round tube T1, the extension line a being orthogonal to the axis L and being parallel to the center line O.

A space between the tubular body 210 and the sleeve 71B is defined as a first valve chamber VS1, and a space below the partition wall 71Bb in the sleeve 71B is defined as a second valve chamber VS 2. The cross hole 71Ba communicates the first valve chamber VS1 with the second valve chamber VS 2.

According to the present embodiment, when the valve shaft holder 32 is displaced downward by energization of the stator coil 53, the movable valve base body 70, which is in a state of being locked to the annular member 73 by gravity, is displaced downward together with the valve shaft holder 32. When the valve shaft holder 32 is further displaced downward, the seat surface 72c of the movable valve seat body 70 is seated on the valve seat 62 of the valve seat member 60. When the valve shaft holder 32 is further displaced downward from this state, the annular member 73 is separated from the top wall 71Bb, and then the upper stepped portion 24f of the valve shaft 24 abuts against the upper surface of the top wall 71Bb of the sleeve 71, and the seat surface 72c is pressed against the valve seat 62 by the elastic force of the coil spring 34, thereby blocking the flow of the refrigerant between the seat surface 72c and the valve seat 62.

On the other hand, in a state where the upper step portion 24f of the valve shaft 24 abuts against the upper surface of the ceiling wall 71Bb of the sleeve 71B, a gap is generated between the fourth shaft portion 24d and the cylindrical hole 72d, and therefore the refrigerant passes through at a flow rate corresponding to the gap.

On the other hand, when the valve shaft 24 is displaced upward by the reverse current, a gap is formed between the fourth shaft 24d and the cylindrical hole 72d in accordance with the displacement amount, and therefore a small flow rate of the refrigerant corresponding to the flow path cross-sectional area flows.

However, when the refrigerant (mixed refrigerant) in which liquid and gas are mixed is supplied from the supply-side round tube T1 to the first valve chamber VS1, when the mixed refrigerant passes through the small-diameter valve port having the smallest flow path cross-sectional area, there is a case where noise is generated by the alternating passage of liquid and gas.

According to the present embodiment, when the mixed refrigerant is supplied from the supply side round tube T1 to the first valve chamber VS1, the liquid having a relatively high specific gravity stays on the seat portion 72 side, but the gas (gas) having a relatively low specific gravity moves to the upper portion side of the sleeve 71B, and the gas moves to the second valve chamber VS2 through the transverse hole 71Ba and stays above the second valve chamber VS 2. Therefore, the refrigerant passing through the small-diameter valve port from the second valve chamber VS2 is only gas, and noise can be suppressed from being generated when the refrigerant passes through.

[ fourth embodiment ]

Fig. 13 is a longitudinal sectional view showing a motor-operated valve 10C according to a fourth embodiment. Fig. 14 is an enlarged cross-sectional view showing the periphery of a valve chamber in the motor-operated valve 10C of fig. 13. In the present embodiment, the valve main body 20C, the valve shaft 24C, and the moving valve seat body 70C are different from those of the first embodiment. The seat portion 72 has the same configuration as that of the first embodiment, but is different from the supply side circular tube T1 in the relative positional relationship. The same components as those of the first embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

As shown in fig. 13 and 14, in the holder 220C, a reduced diameter portion 226 is formed on the lower outer periphery of the hollow cylindrical portion 221C. The upper end of the reduced diameter portion 226 is located at substantially the same height as the lower surface of the partition wall 222C. A supply-side circular tube (pipe for supplying fluid) T1 inserted through the circular hole 211 of the tubular main body 210C is positioned with respect to the tubular main body 210C by the tip end thereof abutting against the lower end of the reduced diameter portion 226. In this state, the supply side round tube T1 is brazed to the tubular body 210C.

In fig. 14, the movable valve seat body 70C, which is displaceable in the axial line L direction within the cylindrical body 210C, includes a cylindrical sleeve 71C and a disc-shaped seat portion 72, the sleeve 71C is slidably fitted to the lower end inner periphery of the hollow cylindrical portion 221C, and the seat portion 72 is joined to the lower end of the sleeve 71C. The sleeve 71C has a cylindrical peripheral wall 71Ca and a partition wall 71Cb formed in the middle of the cylindrical peripheral wall 71Ca in the axial direction. A circular opening 71Cc is formed in the center of the partition wall 71 Cb. A groove (notch) 76 is formed around the circular opening 71 Cc. Even in a state where step portion 24Cf of valve shaft 24C abuts partition wall 71Cb, the refrigerant can move through groove (notch) 76.

As shown in fig. 13, the valve shaft 24C is formed by coaxially and continuously providing the first shaft portion 24Ca, the second shaft portion 24Cb, the third shaft portion 24Cc, the fourth shaft portion 24Cd, and the valve portion 24Ce, but the second shaft portion 24Cb is longer than that of the first embodiment.

A space between the tubular body 210C and the sleeve 71C is defined as a first valve chamber VS1, and a space below the partition wall 71Cb in the sleeve 71C is defined as a second valve chamber VS 2.

In the present embodiment, a third valve chamber VS3 is formed between the holder 220C and the sleeve 71C (above the partition wall 71 Cb) fitted to the holder 220C. The first valve chamber VS1 and the third valve chamber VS3 communicate with each other via a through opening (through hole) 227, the through opening 227 is provided in the reduced diameter portion 226 so as to be spaced upward from the supply-side round tube T1, and the third valve chamber VS3 and the second valve chamber VS2 communicate with the gap (including the groove 76) of the circular hole 225C via the valve shaft 24C.

The seat member 60C on which the seat portion 72 is seated differs from the first embodiment only in that the thin cylindrical portion 61C on the upper end side is extended upward. In the present embodiment, the supply-side circular tube T1 is not in contact with the thin-walled cylindrical portion 61C, but is separated upward therefrom. A liquid accumulation space LS, which is a part of the first valve chamber VS1, is formed between the seat member 60C and the inner peripheral lowermost end of the supply side round tube T1 (around the seat portion 72 and the thin-walled cylindrical portion 61C), that is, at the bottom of the valve main body 20B. By extending the thin cylindrical portion 61C upward, the volume of the liquid storage space LS can be increased.

In the present embodiment as well, when the mixed refrigerant is supplied from the supply-side round tube T1 to the first valve chamber VS1, the liquid having a relatively high specific gravity moves toward the seat 72 and stays in the liquid accumulation space LS. On the other hand, the gas having a relatively low specific gravity moves to the upper side of the sleeve 71C, passes between the cylindrical body portion 210C and the reduced diameter portion 226, moves to the third valve chamber VS3 through the through opening 227, and accumulates in the third valve chamber VS 3. Therefore, the refrigerant passing through the small-diameter valve port from the second valve chamber VS2 is only gas, and noise can be suppressed from being generated when the refrigerant passes through.

[ fifth embodiment ]

Fig. 15 is a longitudinal sectional view showing the motor-operated valve 10D of the fifth embodiment. Fig. 16 is an enlarged cross-sectional view showing the periphery of the valve chamber in the motor-operated valve 10D of fig. 15. In the present embodiment, the shape of the sleeve 71D for moving the valve seat body 70D is different from that of the fourth embodiment, but the seat portion 72 is the same as that of the fourth embodiment. The same components as those of the fourth embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

In the present embodiment, instead of providing the partition wall 71Db with a groove (cutout), the sleeve 71D has one or more vertical holes 77 on the radially outer side of the step portion 24 Cf.

In the present embodiment as well, when the mixed refrigerant is supplied from the supply-side round tube T1 to the first valve chamber VS1, the liquid having a relatively high specific gravity moves toward the seat 72 and stays in the liquid accumulation space LS. On the other hand, the gas having a relatively low specific gravity moves to the upper side of the sleeve 71D, moves to the third valve chamber VS3 through the through opening 227, and accumulates in the third valve chamber VS 3. When the liquid enters the third valve chamber VS3, the liquid moves toward the second valve chamber VS2 through the vertical hole 77. Therefore, the refrigerant passing through the small-diameter valve port from the second valve chamber VS2 is only gas, and noise can be suppressed from being generated when the refrigerant passes through.

[ sixth embodiment ]

Fig. 17 is an enlarged cross-sectional view showing the periphery of a valve chamber of the motor-operated valve according to the sixth embodiment. In the present embodiment, the shapes of the valve shaft 24E and the seat portion 72E of the movable valve seat body 70E are different from those of the third embodiment. However, the sleeve 71 is the same as the third embodiment. The valve shaft 24E is not formed with a structure corresponding to the upper step portion 24 f. The same components as those of the third embodiment are denoted by the same reference numerals, and redundant description thereof is omitted.

The valve portion 24Ee of the valve shaft 24E has a double-tapered shape as shown in fig. 17, and more specifically, the valve portion 24Ee has a first valve portion 24Ee1 adjacent to the fourth shaft portion 24Ed and a second valve portion 24Ee2 adjacent to the first valve portion 24Ee 1. As in the third embodiment, the taper angle of the first valve portion 24Ee1 is larger than the taper angle of the second valve portion 24Ee 2.

The communication hole 72Ef of the seat 72E serving as the valve port includes a small tapered portion 72Eg, a cylindrical hole 72Ed adjacent to the small tapered portion 72Eg, and a tapered hole 72Ee adjacent to the cylindrical hole 72 Ed.

According to the present embodiment, when the valve shaft 24E is displaced downward by applying current to the stator coil 53 (see fig. 1), the first valve portion 24E 1 is seated on the small tapered portion 72Eg, and therefore, the gap between the valve portion 24E and the communication hole 72Ef disappears, and the refrigerant does not pass therebetween. Further, as long as the seat surface 72c of the seat portion 72E is seated on the valve seat 62 of the valve seat member 60, the refrigerant does not pass therebetween, and therefore the flow of the refrigerant from the supply-side round tube T1 to the discharge-side round tube T2 is shut off.

On the other hand, when the valve shaft 24E is displaced upward by the reverse current, a gap is formed between the valve portion 24E and the communication hole 72Ef according to the displacement amount, and therefore a small flow rate of the refrigerant corresponding to the flow path cross-sectional area flows.

Further, when the reverse direction current is continued, referring to fig. 11, the annular member 73 abuts against the lower surface of the top wall 71b of the sleeve 71, and the movable valve seat body 70E is lifted by the valve shaft 24E, so that a gap is generated between the seat surface 72c of the movable valve seat body 70E and the valve seat 62 of the valve seat member 60. Thereafter, since the gap between the seat surface 72c and the valve seat 62 changes according to the displacement amount of the valve shaft 24E, a large flow rate of the refrigerant corresponding to the flow path cross-sectional area thereof flows.

Further, when a groove (notch) (not shown) is formed in the small conical portion 72Eg of the electric valve in the direction along the flow direction, a predetermined minute flow rate flow (flow rate equivalent to the point a in fig. 2) can be formed in a state where the first valve portion 24Ee1 is seated on the small conical portion 72Eg (the range of the control pulse number from 0 to the point a' in fig. 2). In addition, the groove (notch) is preferably formed in plural.

The present invention is not limited to the above-described embodiments. Any components of the above-described embodiments may be modified within the scope of the present invention. In the above-described embodiment, any component can be added or omitted.

Claims

1. An electrically operated valve, comprising:

a pipe for supplying fluid is connected to the first valve chamber,

the communication hole that communicates the first valve chamber with the second valve chamber is provided above an upper end of an inner periphery of the pipe.

2. Electrically operated valve according to claim 1,

when the step of the valve shaft abuts against the movable valve seat body, the flow path adjustment portion is located at the lower end position.

3. Electrically operated valve according to claim 1 or 2,

the flow path adjustment portion is a tapered portion.

4. Electrically operated valve according to any of claims 1 to 3,

the movable valve seat body includes a seat portion that includes the small-diameter valve port and abuts the large-diameter valve port, and a sleeve that is coupled to the seat portion and includes a partition wall, and the valve shaft is inserted into the second valve chamber through an opening formed in the partition wall of the sleeve.

5. Electrically operated valve according to claim 4,

the communication hole is provided in the peripheral wall of the sleeve.

6. Electrically operated valve according to claim 4 or 5,

the step portion is disposed on one side of the valve shaft and the engaging portion is disposed on the other side of the valve shaft with the partition wall interposed therebetween.

7. Electrically operated valve according to any of claims 4 to 6,

the pipe for supplying the fluid is separated upward from the seat portion.

8. Electrically operated valve according to any of claims 1 to 7,

the valve body has: a body formed from tubing; and a guide portion disposed inside the main body and guiding the movable valve seat body, wherein the valve main body has the communication hole in the guide portion.

9. Electrically operated valve according to claim 8,

a third valve chamber is formed between the guide portion and the moving seat body, and the first valve chamber and the third valve chamber communicate with each other via the communication hole.

10. Electrically operated valve according to claim 8 or 9,

a liquid storage space is provided below the fluid supply pipe in the valve main body.

11. Electrically operated valve according to any of claims 8 to 10,

the pipe for supplying the fluid is positioned by abutting against the guide portion.