JP2024014977A - Motor valve - Google Patents

Abstract

To suppress generation of noise and vibration of a motor valve by stabilizing the state of a coolant in an auxiliary valve chamber and reducing the acoustic pressure of the coolant passing sound at a port throttle portion between an auxiliary valve port formed on a main valve body and an auxiliary valve body, for a motor valve which controls the flow rate in a small flow-rate control range of the coolant with the port throttle portion.SOLUTION: A guide boss portion 41 inserted into an auxiliary valve chamber 3R is provided for an auxiliary valve body 4. A throttle passage S1 is formed by a clearance between an inner circumference of the auxiliary valve chamber 3R and an outer circumference of the guide boss portion 41. A coolant flowing into a main valve chamber 1R flows to the auxiliary valve chamber 3R through the throttle passage S1 from a communication passage 3b. The coolant in the main valve chamber 1R is stabilized by passing through the throttle passage S1 even when the coolant is a mixture of a gas phase coolant and a liquid phase coolant. The coolant passes through a port throttle portion P from the auxiliary valve chamber 3R.SELECTED DRAWING: Figure 2

Description

The present invention relates to an electric valve used in a refrigeration cycle system or the like.

BACKGROUND ART Conventionally, as an electric valve provided in a refrigeration cycle of an air conditioner, there is an electric valve that controls the flow rate in a small flow rate control area and a large flow rate area. Such an electric valve is disclosed in, for example, Japanese Patent Application Publication No. 2020-106086 (Patent Document 1).

FIG. 9 is an enlarged sectional view of the main parts of this conventional electric valve. This conventional motor-operated valve includes a main valve body a and a sub-valve body b, and allows refrigerant to flow into the sub-valve chamber a1 of the main valve body a from the communication passage b3 of the sub-valve body b, and the needle of the sub-valve body b The refrigerant is throttled in a port throttle section P, which is a gap between the valve b2 and the sub-valve port a2, to perform small flow control.

JP2020-106086A

In the motor-operated valve of Patent Document 1, when the state of the refrigerant is unstable, such as when the liquid phase is mixed into the gas phase of the refrigerant flowing into the communication path b3, the refrigerant flows into the port throttle part P without being stabilized. For this reason, there is a problem in that the sound of refrigerant passing through the port constriction portion P increases.

The present invention completely closes the main valve port with the main valve element, and controls the flow rate in a small flow rate control range of refrigerant using the port constriction section between the auxiliary valve port formed on the main valve element and the auxiliary valve element. The purpose of this invention is to stabilize the state of refrigerant in the auxiliary valve chamber, reduce the sound pressure of the sound of refrigerant passing through the port restrictor, and suppress the generation of noise and vibration in the motor-operated valve.

The motor-operated valve of the present invention includes a main valve body that is provided in a main valve chamber of a valve body and opens and closes a main valve port that opens into the main valve chamber, and a main valve body that is disposed in a sub-valve chamber that is formed in the main valve body. a sub-valve body that moves in the axial direction of a sub-valve port formed in the body to control the opening degree of the sub-valve port, and a communication passage communicating from the main valve chamber to the sub-valve chamber is formed. , the main valve port is closed by the main valve body, and the fluid flowing into the auxiliary valve chamber via the communication passage is directed to a port constriction portion in the gap between the needle valve of the auxiliary valve body and the auxiliary valve port. The motor-operated valve having a small flow rate control region to be throttled is characterized in that a stabilizing structure is provided between the communication passage and the port throttle portion to stabilize the state of the fluid in the sub-valve chamber.

In this case, the electric valve is characterized in that the stabilizing structure is constituted by a throttle passage formed by a clearance between the inner periphery of the auxiliary valve chamber and the outer periphery of the auxiliary valve body inserted into the auxiliary valve chamber. is preferred.

Further, the sub-valve body includes a guide boss portion inserted into the sub-valve chamber, and the throttle passage is formed by a clearance between the inner periphery of the sub-valve chamber and the outer periphery of the guide boss. Electrically operated valves with the following characteristics are preferred.

Further, the sub-valve body includes a flange portion inserted into the sub-valve chamber, and an enlarged space opening to the communication passage, and includes a clearance between an inner periphery of the sub-valve chamber and an outer periphery of the flange portion. Preferably, the motor-operated valve is characterized in that the stabilizing structure is constituted by a throttle passage and the enlarged space.

Preferably, the electric valve is characterized in that the flange portion is formed with a through hole penetrating in the axial direction from the enlarged space to the port constriction portion side.

Further, the relationship between the opening area [A] of the communication passage, the opening area [B] of the throttle passage, and the opening area [C] of the port throttle part is as follows:
A>B>C
An electrically operated valve characterized by the following is preferable.

Further, the relationship among the opening area [A] of the communication passage, the opening area [B] of the throttle passage, the opening area [C] of the port throttle part, and the opening area [D] of the through hole is ,
A>B+D>C
An electrically operated valve characterized by the following is preferable.

Preferably, the motor-operated valve is characterized in that the communication passage is formed in the main valve body, and a height from the port constriction portion to the communication passage is larger than a radius of the sub-valve chamber.

According to the motor-operated valve of the present invention, even if the refrigerant is a mixture of gas-phase refrigerant and liquid-phase refrigerant, the state of the refrigerant in the sub-valve chamber is stabilized, and the refrigerant is transferred from the sub-valve chamber to the port throttle section (sub-valve chamber). The condition of the refrigerant before passing through the valve port is stabilized. Therefore, the sound pressure of the refrigerant passing through the port constriction section, which is the gap between the needle valve and the auxiliary valve port, is reduced, and the generation of noise and vibration of the electric valve can be suppressed.

FIG. 2 is a longitudinal cross-sectional view of the electric valve according to the first embodiment of the present invention in a small flow rate control region state. FIG. 2 is an enlarged cross-sectional view of a main part of the electric valve of the first embodiment in a small flow rate control region state. FIG. 2 is an enlarged cross-sectional view of the main part of the electric valve of the first embodiment in a large flow range state. FIG. 7 is an enlarged cross-sectional view of a main part of an electric valve according to a second embodiment of the present invention in a small flow rate control region state. FIG. 7 is an enlarged cross-sectional view of the main part of the motor-operated valve according to the second embodiment in a large flow range state. FIG. 7 is an enlarged sectional view of a main part of an electric valve according to a third embodiment of the present invention in a small flow rate control region state. FIG. 7 is an enlarged sectional view of a main part of an electric valve according to a fourth embodiment of the present invention in a small flow rate control region state. FIG. 7 is an enlarged cross-sectional view of a main part of an electric valve according to a fifth embodiment of the present invention in a small flow rate control region state. FIG. 2 is an enlarged cross-sectional view of a main part of a conventional electric valve.

Next, embodiments of the electric valve of the present invention will be described with reference to the drawings. FIG. 1 is a longitudinal cross-sectional view of the electric valve of the first embodiment in the small flow control region state, FIG. 2 is an enlarged cross-sectional view of the main part of the electric valve in the small flow control region state (sub-valve lower end position), and FIG. 3 is the same FIG. 2 is an enlarged cross-sectional view of the main part of the motor-operated valve in a large flow range state (sub-valve upper end position). Note that the concept of "up and down" in the following description corresponds to the up and down in the drawing of FIG. This electric valve 100 includes a valve housing 1 , a guide member 2 , a main valve body 3 , a sub-valve body 4 , and a drive section 5 .

The valve housing 1 is made of, for example, brass or stainless steel and has a substantially cylindrical shape, and has a main valve chamber 1R inside thereof. A first joint pipe 11 that communicates with the main valve chamber 1R is connected to one side of the outer periphery of the valve housing 1, and a second joint pipe 12 is connected to a cylindrical portion extending downward from the lower end. Further, a main valve seat 13 is formed on the main valve chamber 1R side of the second joint pipe 12 of the valve housing 1, and the inside of this main valve seat 13 is a main valve port 13a. The main valve port 13a is a cylindrical hole centered on the axis L, and the second joint pipe 12 is communicated with the main valve chamber 1R via the main valve port 13a. In this embodiment, the main valve seat 13 is integrally formed with the valve housing 1, but a valve seat member having a main valve port is provided separately from the valve housing, and the valve seat member is attached to the valve housing. It may also be assembled into a form.

A guide member 2 is attached to an opening at the upper end of the valve housing 1 . The guide member 2 includes a fitting part 21 that fits into the inner circumferential surface of the valve housing 1, a substantially cylindrical guide part 22 located above the fitting part 21, and a guide part 22 extending above the guide part 22. A ring-shaped fixture 24 made of a metal plate is provided on the fitting part 21 and protrudes from the outer periphery of the fitting part 21. The fitting part 21, the upper guide part 22, and the holder part 23 are constructed as an integral part made of resin, and the fixing fitting 24 is integrally provided with the fitting part 21 made of resin by insert molding. Note that the fitting portion 21 of the guide member 2 may be press-fitted into the valve housing 1.

The guide member 2 is assembled to the valve housing 1 through a fitting portion 21 and is fixed to the upper end of the valve housing 1 via a fixing fitting 24 by welding. Further, in the guide member 2, a cylindrical guide hole 2A coaxial with the axis L is formed inside the fitting part 21 and the guide part 22, and a cylindrical guide hole 2A coaxial with the guide hole 2A is formed in the center of the holder part 23. A female threaded portion 23a and its screw hole are formed. A main valve body 3 is disposed within the guide hole 2A.

The main valve body 3 includes a main valve part 31 that seats and leaves the main valve seat 13, and a holding part 32 that is a side wall of the main valve body 3 and holds the sub valve body 4. A cylindrical opening 3A is formed inside the main valve part 31, and a cylindrical sub-valve chamber 3R is formed inside the holding part 32, and the inner peripheral surface of the sub-valve chamber 3R is used as a sub-valve guide This is hole 3B. A cylindrical sub-valve port 3a is formed between the main valve part 31 and the holding part 32 and opens from the sub-valve chamber 3R toward the opening 3A with the axis L as the center.

A communication passage 3b communicating from the main valve chamber 1R to the sub-valve chamber 3R in a direction intersecting the axis L is formed on the side surface of the holding portion 32 of the main valve body 3. In this embodiment, a plurality of communicating passages 3b (for example, four) are formed radially at positions that are rotationally symmetrical about the axis L. Further, the main valve body 3 has a retainer 34 at the upper end of the holding part 32, and a main valve spring 35 between the retainer 34 and the upper end of the guide hole 2A of the guide member 2. The main valve body 3 is biased toward the main valve seat 13 (in the closing direction) by the valve spring 35 . Note that a muffling member 36 is disposed inside the opening 3A of the main valve portion 31. Note that the communication passages 3b are not limited to a form in which a plurality of communication passages 3b are formed radially at rotationally symmetrical positions, and the number of communication passages 3b may be one, or a plurality of communication passages 3b may be formed at irregular intervals.

The sub-valve body 4 is provided at the lower end of the rotor shaft 51. Further, the sub-valve body 4 is integrally formed with the rotor shaft. This sub-valve body 4 is composed of a guide boss portion 41 and a needle valve 42. Further, the needle valve 42 of the sub-valve body 4 has its tip inserted into the sub-valve port 3a in the direction of the axis L, and a port constriction portion P, which is a gap between the needle valve 42 and the sub-valve port 3a, is inserted into the sub-valve port 3a in the direction of the axis L. Small flow rate control is performed by flowing a small flow rate of refrigerant. An annular washer 43 made of lubricating resin is disposed at the upper end of the guide boss 41, and the guide boss 41 is inserted into the sub-valve guide hole 3B. The clearance between the outer circumferential surface of the guide boss portion 41 and the inner circumferential surface of the sub-valve guide hole 3B constitutes a throttle passage S1 as a "stabilizing structure." Note that the sub-valve body 4 and the rotor shaft 51 may be formed separately and assembled together.

A case 14 is airtightly fixed to the upper end of the valve housing 1 by welding or the like, and a drive section 5 is configured inside and outside the case 14. The drive unit 5 includes a stepping motor 5A, a screw feeding mechanism 5B that advances and retreats the sub-valve body 4 by rotation of the stepping motor 5A, and a stopper mechanism 5C that restricts the rotation of the stepping motor 5A.

The stepping motor 5A includes a rotor shaft 51, a magnet rotor 52 rotatably disposed inside a case 14, a stator coil 53 disposed opposite to the magnet rotor 52 on the outer periphery of the case 14, and other components shown in the figure. It is made up of a yoke, exterior members, etc. The rotor shaft 51 is attached to the center of the magnet rotor 52 via a bush, and a male threaded portion 51a is formed on the outer periphery of the rotor shaft 51 on the guide member 2 side. The male threaded portion 51a is screwed into the female threaded portion 23a of the guide member 2, so that the guide member 2 supports the rotor shaft 51 on the axis L. The female threaded portion 23a of the guide member 2 and the male threaded portion 51a of the rotor shaft 51 constitute a screw feeding mechanism 5B. A cylindrical portion 14a that holds the rotation stopper mechanism 5C is provided on the inner ceiling of the case 14, and a guide member 54 that guides the upper end of the rotor shaft 51 is disposed within the cylindrical portion 14a.

With the above configuration, when the stepping motor 5A is driven, the magnet rotor 52 and the rotor shaft 51 rotate, and the rotor shaft 51 is moved along with the magnet rotor 52 in the direction of the axis L by the screw feeding mechanism 5B of the male threaded portion 51a and the female threaded portion 23a. Move to. Then, the sub-valve body 4 moves forward and backward in the direction of the axis L, and the needle valve 42 of the sub-valve body 4 approaches or separates from the sub-valve port 3a. Further, when the sub-valve body 4 rises, the washer 43 engages with the retainer 34 of the main valve body 3 (sub-valve upper end position), the main valve body 3 moves together with the sub-valve body 4, and the main valve body 3 The main valve portion 31 is removed from the main valve seat 13. As a result, the main valve port 13a becomes fully open and enters a large flow range state (note that even immediately after the main valve body 3 leaves the main valve seat 13, the main valve port 13a remains fully open and enters a large flow range state. (The state is the same as that shown in FIG. 3, which will be described later). Note that the magnet rotor 52 is formed with a protrusion 52a, and as the magnet rotor 52 rotates, the protrusion 52a operates the rotation stopper mechanism 5C, and the lowermost position of the rotor shaft 51 (and the magnet rotor 52) and The top position is restricted.

In the small flow rate control region state shown in FIG. The opening area of the port constriction portion P is controlled, and a small flow rate is controlled. At this time, the refrigerant that has flowed into the main valve chamber 1R from the first joint pipe 11 flows from the communication passage 3b to the sub-valve chamber 3R through the throttle passage S1. In this way, the refrigerant flows into the sub-valve chamber 3R via the throttle passage S1, so even if the refrigerant in the main valve chamber 1R is a mixture of gas-phase refrigerant and liquid-phase refrigerant, This refrigerant is stabilized by passing through the throttle passage S1, and the state of the refrigerant before passing through the port throttle section P from the sub-valve chamber 3R is stabilized. Therefore, the sound pressure of the refrigerant passing sound at the port constriction portion P is reduced, and the generation of noise and vibration of the electric valve 100 can be suppressed.

Here, in the conventional electric valve shown in FIG. 9, since the height [H1] from the upper edge position of the sub-valve port a2 to the bottom of the communication passage b3 is small, the refrigerant from the communication passage b3 to the port throttle part P is small. The flow distance is short. On the other hand, in this embodiment, as shown in FIG. 2, the height [H3] from the upper edge position of the auxiliary valve port 3a to the bottom of the communication passage 3b is the height [H1] in the conventional electric valve. ], that is, this height [H3] is larger than the radius of the inner diameter of the sub-valve chamber 3a (the inner diameter of the guide hole 3B). In this way, since the height [H3] from the upper edge position of the sub-valve port 3a to the bottom of the communication passage 3b is sufficiently long, the effect of stabilizing the refrigerant is enhanced. Note that FIG. 2 shows the lower end position of the sub-valve body 4 in the small flow rate control region state of the electric valve 100, and in this state, the height [H2] from the sub-valve port 3a to the lower end of the throttle passage S1 is , is lower than the height [H3] from the upper edge position of the sub-valve port 3a to the bottom of the communication passage 3b. In addition, in the large flow range state shown in FIG. 3, the height [H4] from the upper edge position of the auxiliary valve port 3a at the upper end position of the auxiliary valve body 4 to the lower end of the throttle passage S1 is also at the upper edge position of the auxiliary valve port 3a. It is lower than the height [H3] from to the bottom of the communication path 3b. Thereby, the throttle passage S1 can be ensured at all times.

Furthermore, the relationship between the opening area [A] of the communication passage 3b, the opening area [B] of the throttle passage S1, and the opening area [C] of the port throttle part P is as follows:
A>B>C
It becomes. This increases the effect of stabilizing the refrigerant state. In addition, in the case of a configuration in which a plurality of communicating passages 3b are provided, the opening area is the sum of the opening areas of the plurality of communicating passages 3b. In addition, in this embodiment, the opening area of the port restrictor P has the above relationship with the opening area C at the inner diameter of the auxiliary valve port 3a where the needle valve 42 is not inserted into the auxiliary valve port 3a. However, when the needle valve 42 is inserted into the sub-valve port 3a, and the opening area of the gap between the sub-valve port 3a and the needle valve 42 is set to C, the above relationship is established. May be set.

FIG. 4 is an enlarged cross-sectional view of a main part of an electric valve according to a second embodiment of the present invention in a small flow control region state, and FIG. 5 is an enlarged cross-sectional view of a main part of an electric valve according to a second embodiment of the present invention in a large flow control region state. In the following second to fifth embodiments, other parts other than the main parts shown are the same as those in FIG. 1 of the first embodiment. Further, in each of the following embodiments, the same members and elements as in the first embodiment are denoted by the same reference numerals, and detailed explanations thereof will be omitted. The second embodiment differs from the first embodiment in the configuration of the sub-valve body 4'.

The sub-valve body 4' in the second embodiment includes a guide boss portion 41' similar to the first embodiment that is inserted into the sub-valve chamber 3R, and a side from the guide boss portion 41' to the sub-valve port 3a. The flange portion 43' is formed at a position spaced apart from the flange portion 43'. Furthermore, an enlarged space 4a' is provided between the guide boss part 41' and the flange part 43'. The flange portion 43' is disc-shaped, and a throttle passage S2 is formed by the clearance between its outer peripheral surface and the inner peripheral surface of the sub-valve guide hole 3B. Further, the enlarged space 4a' opens to the communication path 3b. The throttle passage S2 and the enlarged space 4a' constitute a "stabilizing structure". The refrigerant that has flowed into the main valve chamber 1R from the first joint pipe 11 flows out from the communication passage 3b into the enlarged space 4a', and further flows into the auxiliary valve chamber 3R through the throttle passage S2. In this way, since the refrigerant flows into the sub-valve chamber 3R via the expanded space 4a' and the throttle passage S2, the ratio of the liquid phase changes due to fluctuations in the ratio of the gas phase to the liquid phase in the refrigerant in the main valve chamber 1R. Even if the refrigerant increases, the gas phase and liquid phase in the refrigerant are equalized within the expanded space 4a', so that the refrigerant before passing from the auxiliary valve chamber 3R to the port throttle part S (auxiliary valve port) condition becomes more stable. Therefore, the sound pressure of the refrigerant passing sound at the port constriction portion P is reduced, and the generation of noise and vibration of the electric valve 100 can be suppressed. Further, since the flow velocity of the fluid flowing into the enlarged space 4a' is reduced, it is also possible to suppress the generation of noise and vibration caused by the disappearance of bubbles generated when colliding with the wall surface. In addition, in the large flow range state shown in FIG. 5, the height from the upper edge position of the auxiliary valve port 3a at the upper end position of the auxiliary valve body 4' to the lower end of the throttle passage S2 is also from the upper edge position of the auxiliary valve port 3a to the communicating path. It is lower than the height to the bottom of 3b. Thereby, the throttle passage S2 can be ensured at all times.

Furthermore, the relationship between the opening area [A] of the communication passage 3b, the opening area [B] of the throttle passage S2, and the opening area [C] of the port throttle part P is as follows:
A>B>C
It becomes. This increases the effect of stabilizing the refrigerant state. Note that the opening area A and the opening area C can be set in the same manner as in the first embodiment.

FIG. 6 is an enlarged sectional view of the main part of the electric valve according to the third embodiment in a small flow rate control region state. In this third embodiment, an enlarged space 3c is formed on the side of the auxiliary valve chamber 3R of the communication passage 3b. This third embodiment is also the same as the second embodiment, and the refrigerant flows out from the communication passage 3b into the expanded space 3c and further flows into the sub-valve chamber 3R through the throttle passage S1, so that the refrigerant flows inside the main valve chamber 1R. Even if the ratio of the liquid phase increases due to fluctuations in the ratio of the gas phase and liquid phase in the refrigerant, the gas and liquid phases in the refrigerant are equalized within the expanded space 3c. The state of the refrigerant before passing from the chamber 3R to the port constriction portion P (auxiliary valve port) becomes more stable. Therefore, the sound pressure of the refrigerant passing sound at the port constriction portion P is reduced, and the generation of noise and vibration of the electric valve 100 can be suppressed. Further, since the flow velocity of the fluid flowing out into the expanded space 3c is reduced, it is also possible to suppress the generation of noise and vibration caused by the disappearance of bubbles generated when colliding with the wall surface.

FIG. 7 is an enlarged cross-sectional view of the main part of the electric valve according to the fourth embodiment in a small flow rate control region state. In the fourth embodiment, an enlarged space 44'' is provided in the guide boss portion 41'' of the sub-valve body 4'' at a portion facing the communication path 3b. 41'' is formed by a hole bored from the outer peripheral surface toward the axis L. The inner diameter of this hole is made sufficiently larger than the inner diameter of the communication passage 3b. In other words, this enlarged space 44'' is completely It is not something that is set up around the area. In this fourth embodiment, as in the second embodiment, the refrigerant flows out from the communication passage 3b into the enlarged space 44'' and further flows into the sub-valve chamber 3R through the throttle passage S1, so that the refrigerant flows inside the main valve chamber 1R. Even if the ratio of the liquid phase increases due to fluctuations in the ratio of the gas and liquid phases in the refrigerant, the gas and liquid phases in the refrigerant are equalized within the expanded space 44'', so The state of the refrigerant before passing from the valve chamber 3R to the port throttle part P (auxiliary valve port) becomes more stable. Therefore, the sound pressure of the refrigerant passing sound at the port constriction portion P is reduced, and the generation of noise and vibration of the electric valve 100 can be suppressed. Furthermore, since the flow velocity of the fluid flowing out into the enlarged space 44'' is reduced, it is also possible to suppress the generation of noise and vibration caused by the disappearance of bubbles generated when colliding with the wall surface.

FIG. 8 is an enlarged sectional view of a main part of the electric valve of the fifth embodiment in a small flow rate control region state. In this fifth embodiment, a through hole 45' is formed in the flange portion 43' of the sub-valve body 4' similar to the second embodiment, penetrating in the axis L direction from the enlarged space 4a to the port constriction portion P side. It is. In this fifth embodiment, the refrigerant flows out from the communication path 3b into the expanded space 4a. The refrigerant then flows into the sub-valve chamber 3R through the throttle passage S2 and the through hole 45'. Therefore, even if the ratio of the liquid phase increases due to a change in the ratio of the gas phase to the liquid phase in the refrigerant in the main valve chamber 1R, the gas phase and liquid phase in the refrigerant in the expanded space 4a will change. Since the refrigerant is equalized, the state of the refrigerant before passing from the sub-valve chamber 3R to the port throttle part P becomes more stable. Therefore, the sound pressure of the refrigerant passing sound at the port constriction portion P is reduced, and the generation of noise and vibration of the electric valve 100 can be suppressed. Further, since the flow velocity of the fluid flowing into the expanded space 4a is reduced, it is also possible to suppress the generation of noise and vibration caused by the disappearance of bubbles generated when colliding with the wall surface.

Also, the relationship between the opening area [A] of the communication passage 3b, the opening area [B] of the throttle passage S2, the opening area [C] of the port throttle part, and the opening area [D] of the through hole 45' is ,
A>B+D>C
It becomes. This increases the effect of stabilizing the refrigerant state. Note that the opening area A and the opening area C can be set in the same manner as in the first embodiment.

Note that in the third, fourth, and fifth embodiments, illustrations of the respective large flow range states are omitted, but the point that the throttle passage can always be ensured even in the large flow range state is that the first embodiment , is similar to the second embodiment.

Further, in the embodiment of the present invention, the main valve body is provided with a communication passage, but instead of providing a communication passage in the main valve body, for example, a D cut is provided in the guide boss portion, and the inside of the main valve body is provided with a D cut. A communication path can also be formed by the peripheral surface (auxiliary valve guide hole 3B) and the D cut.

The embodiments of the present invention have been described above in detail with reference to the drawings, and other embodiments have also been described in detail, but the specific configuration is not limited to these embodiments. Even if there are changes in the design within the scope of the invention, they are included in the present invention.

1 Valve housing 1R Main valve chamber 11 First joint pipe 12 Second joint pipe 13 Main valve seat 13a Main valve port L Axis 2 Guide member 2A Guide hole 22 Guide portion 23 Holder portion 23a Female thread portion 3 Main valve body 31 Main valve portion 32 Holding section 3a Sub-valve port 3b Communication path 3B Sub-valve guide hole 3R Sub-valve chamber 4 Sub-valve body 41 Guide boss section 42 Needle valve 5 Drive section 5A Stepping motor 5B Screw feed mechanism 5C Stopper mechanism 51 Rotor shaft 51a Male thread section 52 Magnet rotor 53 Stator coil 4' Sub-valve body 41' Guide boss section 43' Flange section 4a' Expanded space 4'' Sub-valve body 41'' Guide boss section 44'' Expanded space 3c Expanded space 100 Motor-operated valve

The motor-operated valve of the present invention includes a valve body including a main valve chamber and a main valve port, a main valve body that opens and closes the main valve port, and a sub-valve body that changes the opening degree of a sub-valve port formed in the main valve body. a valve body , the main valve body is connected to the auxiliary valve body so as to be movable relative to the axial direction, and includes a communication passage whose one opening opens into the main valve chamber; A sub-valve chamber is formed by a flow path from the other opening of the passage to the sub-valve port, and the main valve port is closed by the main valve body, and the sub-valve is opened from the main valve chamber via the communication passage. In an electric motor-operated valve having a small flow rate control region in which fluid flowing into a port is throttled by a port restricting portion in a gap between the needle valve of the sub-valve body and the sub-valve port, there is provided a space between the communication passage and the sub-valve port . , comprising a stabilizing structure for stabilizing the state of fluid in the sub-valve chamber , an enlarged space opening on the side of the communication passage of the sub-valve chamber, communicating the enlarged space with the sub-valve port; A throttle passage whose cross-sectional area when viewed from the direction is smaller than the cross-sectional area when the expansion space is viewed from the axial direction constitutes the stabilizing structure, and a throttle passage is provided between the needle valve of the sub-valve body and the expansion space. , a disc-shaped part extending in a direction intersecting the axial direction is provided, and the disc-shaped part is provided with a through hole penetrating in the axial direction at a position radially outward with respect to the needle valve. It is characterized by the presence of

In this case , the needle valve is characterized in that it includes a cylindrical portion that faces an inner wall of the auxiliary valve port while being inserted into the auxiliary valve port .

Further, the throttle passage is characterized in that it consists of a clearance between an inner periphery of the auxiliary valve chamber and an outer periphery of the auxiliary valve body inserted into the auxiliary valve chamber .

Preferably, the motor-operated valve is characterized in that the throttle passage is formed by a clearance between the inner periphery of the sub-valve chamber and the outer periphery of the disc-shaped portion .

Preferably, the motor-operated valve is characterized in that a height from the port constriction portion to the communication passage is larger than a radius of the auxiliary valve chamber.

Claims (8)

A main valve body that is provided in a main valve chamber of a valve body and opens and closes a main valve port that opens into the main valve chamber, and a sub-valve that is formed in the main valve body in a sub-valve chamber that is formed in the main valve body. a sub-valve body that moves in the axial direction of the port to control the opening degree of the sub-valve port, a communication passage communicating from the main valve chamber to the sub-valve chamber is formed, and the main valve body controls the opening of the sub-valve port. The main valve port is closed, and the fluid flowing into the auxiliary valve chamber via the communication path is throttled by a port throttle portion in the gap between the needle valve of the auxiliary valve body and the auxiliary valve port. In electric valves,
An electrically operated valve comprising a stabilizing structure for stabilizing the state of fluid in the sub-valve chamber between the communication passage and the port constriction section. 2. The stabilizing structure according to claim 1, wherein the stabilizing structure is constituted by a throttle passage formed by a clearance between an inner periphery of the auxiliary valve chamber and an outer periphery of the auxiliary valve body inserted into the valve chamber. Electric valve. The auxiliary valve body is provided with a guide boss portion inserted into the auxiliary valve chamber, and the throttle passage is configured by a clearance between an inner periphery of the auxiliary valve chamber and an outer periphery of the guide boss. The electric valve according to claim 2. The sub-valve body includes a flange portion inserted into the sub-valve chamber, and an enlarged space opening to the communication passage, and a throttle passage formed by a clearance between the inner periphery of the sub-valve chamber and the outer periphery of the flange portion. The electric valve according to claim 1, wherein the stabilizing structure is constituted by the and the enlarged space. 5. The motor-operated valve according to claim 4, wherein the flange portion is formed with a through hole penetrating in the axial direction from the enlarged space to the port throttle portion side. The relationship between the opening area [A] of the communication passage, the opening area [B] of the throttle passage, and the opening area [C] of the port throttle part is:
A>B>C
The motor-operated valve according to any one of claims 2 to 4, characterized in that: The relationship between the opening area [A] of the communication passage, the opening area [B] of the throttle passage, the opening area [C] of the port throttle part, and the opening area [D] of the through hole is:
A>B+D>C
The electric valve according to claim 5, characterized in that: 8. The communication passage is formed in the main valve body, and the height from the port constriction part to the communication passage is larger than the radius of the auxiliary valve chamber. Electric valve described in.

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