CN112483658A

CN112483658A - Electric valve

Info

Publication number: CN112483658A
Application number: CN202010954084.8A
Authority: CN
Inventors: 松本道雄; 佐伯真司; 三浦洋一; 汤浅智宏
Original assignee: TGK Co Ltd
Current assignee: TGK Co Ltd
Priority date: 2019-09-12
Filing date: 2020-09-11
Publication date: 2021-03-12
Anticipated expiration: 2040-09-11
Also published as: JP7266871B2; JP2021042820A; CN112483658B

Abstract

The obstruction of the drive of the motor-operated valve due to foreign matter mixed in the fluid is prevented or suppressed. The electric valve includes: the screw feeder comprises a main body, a shell (302), a motor and a screw feeding mechanism. The body has an inlet port through which fluid is introduced from an upstream side, an outlet port through which the fluid is discharged to a downstream side, and a passage that communicates the inlet port and the outlet port. The housing (302) divides an internal space (R) to which the pressure of the fluid acts and an external space to which the pressure of the fluid does not act. The motor includes a rotor (320) for driving the valve element in the opening/closing direction of the valve portion, and a stator (340) coaxially inserted in the housing (302). The screw feed mechanism is located inside the housing (302) and converts the rotational movement of the rotor (320) into a translational movement. A1 st clearance (Cl2) is formed between a thread of the male screw part (244) and a thread of the female screw part (328) in the screw feeding mechanism, and a minimum value of the 1 st clearance (Cl2) is larger than a maximum value of a clearance (Cl1) communicating the internal space (R) and the passage.

Description

Electric valve

Technical Field

The present disclosure relates to an electrically operated valve, and more particularly, to a flow path structure.

Background

In general, an automotive air conditioner is configured by arranging a compressor, a condenser, an expansion device, an evaporator, and the like in a refrigeration cycle. The expansion device expands the liquid refrigerant condensed by the condenser into a mist-like gas-liquid mixed refrigerant by receiving a flow, and sends the mist-like gas-liquid mixed refrigerant to the evaporator. As the expansion device, an electric expansion valve is used in which a driving unit uses a motor to precisely control the valve opening. Such a motor-driven expansion valve has a mechanism for bringing a valve element supported at the tip end of a shaft into contact with and out of a valve seat provided in a main body. A technique is proposed in which a screw feed mechanism is used to convert the rotational motion of the rotor into the translational motion of the shaft at the time of this contact/disengagement.

Such an electric expansion valve is provided with a housing that is fixed to the main body and that isolates the rotor from the outside air. A refrigerant is introduced into an internal space formed inside the housing and including the rotor and the screw feeding mechanism. Conventionally, a refrigerant into which foreign matter has been mixed flows into an internal space of a housing, and a problem has arisen that driving of a screw feed mechanism is hindered. In order to solve this problem, a technique is known in which a flow path to an internal space is narrowed to remove foreign matter contained in a refrigerant (see, for example, patent document 1).

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2012-127504

Disclosure of Invention

[ problems to be solved by the invention ]

However, small foreign matter that can pass through a narrow flow path connected to the internal space sometimes enters the screw portion of the screw feeding mechanism. In the electric expansion valve, such a minute foreign matter bites into the screw portion, and may hinder the driving of the valve body. Such a problem may occur not only in the electric expansion valve but also in various electric valves.

The present invention has been made in view of the above problems, and an object thereof is to prevent or suppress the driving of the motor-operated valve from being hindered by foreign matter mixed in the fluid.

[ means for solving the problems ]

One aspect of the present invention is an electrically operated valve. The electric valve comprises: a main body provided with an inlet port for introducing a fluid from an upstream side, an outlet port for discharging the fluid to a downstream side, and a passage for communicating the inlet port with the outlet port; a valve element that opens and closes a valve portion provided in the passage; a rotor for driving the valve element in the opening and closing direction of the valve portion; a shaft that is coaxially connected to the rotor and is displaceable integrally with the valve element; a housing which is a cylindrical member fixed to the main body and containing the rotor therein and which divides an internal space in which a pressure of the fluid acts and an external space in which the pressure of the fluid does not act; a motor including a rotor and a stator coaxially inserted into the housing; and a screw feeding mechanism which is positioned inside the housing and converts the rotary motion of the rotor into a translational motion. A1 st clearance is formed between the thread of the male screw portion and the thread of the female screw portion in the screw feeding mechanism. The minimum value of the 1 st gap is larger than the maximum value of the gap communicating the internal space and the passage.

According to this aspect, the size of the foreign matter introduced into the internal space is smaller than the gap. Further, by making the 1 st gap larger than the gap, biting of the screw portion by foreign matter introduced into the 1 st gap is prevented or suppressed. Therefore, it is possible to prevent or suppress the drive of the valve element from being hindered in the motor-operated valve.

[ Effect of the invention ]

According to the present invention, it is possible to prevent or suppress the foreign matter mixed in the fluid from obstructing the driving of the motor-operated valve.

Drawings

Fig. 1 is a sectional view showing a structure of an electric valve unit.

Fig. 2 is a cross-sectional view showing an opened state of the motor-operated valve.

Fig. 3 is an enlarged cross-sectional view of portion a in fig. 1.

Fig. 4 is an enlarged cross-sectional view of a portion B in fig. 1.

Fig. 5 is an enlarged cross-sectional view of portion C in fig. 1.

Fig. 6 is an enlarged cross-sectional view of the X portion in fig. 1.

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following description, for convenience, the positional relationship of the respective structures may be expressed with reference to the illustrated state. In the following embodiments and modifications thereof, the same reference numerals are given to substantially the same components, and descriptions thereof are omitted as appropriate.

[ embodiment ]

Fig. 1 is a sectional view showing the structure of an electric valve unit U according to the embodiment. The motor-operated valve unit U includes a motor-operated valve 1 and a pipe main body 2. The motor-operated valve 1 is applied to a refrigeration cycle of an automobile air conditioner not shown. The refrigeration cycle includes a compressor for compressing a refrigerant to be circulated, a condenser for condensing the compressed refrigerant, an expansion valve for throttling and expanding the condensed refrigerant and sending the refrigerant in a mist form, an evaporator for evaporating the refrigerant in the mist form and cooling air in a vehicle compartment by latent heat of evaporation thereof, and the like. The motor-operated valve 1 functions as an expansion valve of the refrigeration cycle.

The motor-operated valve 1 is assembled to the motor unit 300 of the valve main body 200. The valve body 200 has a body 220 that houses the valve portion 202. The main body 220 functions as a "valve body". The main body 220 is formed by coaxially assembling a cylindrical 1 st main body 240 and a cylindrical 2 nd main body 260.

The 1 st body 240 is disposed on the upper half of the piping body 2. A 2 nd body 260 is disposed on a lower half of the 1 st body 240. The 2 nd body 260 is located inside the pipe body 2. The 2 nd main body 260 accommodates a valve portion 202 therein. A guide member 242 (guide portion) stands on the center of the upper portion of the 1 st body 240. The guide member 242 is a machined product made of a metal material, and a male screw portion 244 is formed on an outer peripheral surface of an axial center portion of the guide member 242. The lower end of the guide member 242 is formed to have a large diameter, and the large diameter portion 245 is coaxially fixed to the upper center of the 1 st body 240. A shaft 246 extending from the rotor 320 of the motor unit 300 is inserted into the 1 st body 240. The lower end portion of the shaft 246 also serves as the valve body 204 constituting the valve portion 202. The guide member 242 supports the shaft 246 slidably in the axial direction by its inner peripheral surface, and supports the rotary shaft 326 (guided portion) of the rotor 320 rotatably slidably by its outer peripheral surface.

An inlet port 222 is provided at one side of the pipe main body 2, and an outlet port 224 is provided at the other side. The inlet port 222 introduces fluid and the outlet port 224 discharges fluid. The inlet port 222 and the outlet port 224 communicate through an internal passage formed in the 2 nd body 260.

The 2 nd body 260 has an inlet port 262 at a side portion thereof and an outlet port 264 at a bottom portion thereof. The inlet port 262 communicates with the inlet port 222, and the outlet port 264 communicates with the outlet port 224. The inlet port 262 and the outlet port 264 communicate via a valve chamber 266. The 2 nd body 260 has a valve hole 208 formed therein, and a valve seat 210 is formed at an upper end edge of the valve hole. The opening degree of the valve portion 202 is adjusted by the contact/separation of the valve element 204 with/from the valve seat 210.

An E-ring 212 is fitted in a lower portion of the shaft 246 inside the valve chamber 266. A spring support 214 is provided above the E-ring 212. A spring receiver 248 is also provided below the guide member 242, and a spring 216 that biases the valve body 204 in the valve closing direction of the valve portion 202 is inserted between the 2

spring receivers

214 and 248 coaxially with the valve body 204. In the present embodiment, the lower end portion of the shaft 246 also serves as the valve body 204, and therefore the spring 216 also biases the shaft 246 in the valve closing direction.

Next, the structure of the motor unit 300 is explained.

The motor unit 300 is configured as a three-phase stepping motor including a rotor 320 and a stator 340. The motor unit 300 includes a bottomed cylindrical case 302, and a rotor 320 and a stator 340 are disposed inside and outside the case 302.

The stator 340 includes a laminated core 342 and a bobbin 344. The laminated core 342 is formed by laminating plate-like cores in the axial direction. A coil 346 is wound around the bobbin 344. The coil 346 and the bobbin 344 around which the coil 346 is wound are collectively referred to as a "coil unit 345". The coil unit 345 is assembled to the laminated core 342.

The stator 340 is integrally provided with the housing 400 by molding. A lid 440 is snap-fitted to the upper end opening of the housing 400. Printed wiring board 420 is disposed in space S surrounded by case 400 and lid 440. The coil 346 is connected to the printed wiring board 420. The housing 400 is provided with a terminal cover 402 for protecting a terminal 422 for supplying power from an external power source to the printed wiring board 420.

The rotor 320 includes a cylindrical rotor core 322 and a magnet 324 provided along the outer periphery of the rotor core 322. The rotor core 322 is assembled to the rotating shaft 326. The magnet 324 is magnetized in its circumferential direction to be multipolar.

The rotary shaft 326 is a machined product made of a metal material. The rotating shaft 326 is formed by integrally molding a metal material into a bottomed cylindrical shape. The rotary shaft 326 is externally fitted with its open end facing downward to the guide member 242. A female screw portion 328 is formed on the inner peripheral surface of the rotary shaft 326 and engages with the male screw portion 244 of the guide member 242. The rotational motion of the rotor 320 is converted into a translational motion in the axial direction by a screw feed mechanism formed by these screw portions. The engagement portion between the female screw 328 and the male screw 244 of the screw feeding mechanism is referred to as a "screwing portion".

As described above, the spring 216 biases the valve body 204 and the shaft 246 in the valve closing direction. When the valve is opened, the upper surface of the thread of the male screw portion 244 abuts against the lower surface of the thread of the female screw portion 328 by the biasing force of the spring 216 in the valve closing direction of the shaft 246. Therefore, the rattling in the thrust direction generated between the male screw portion 244 and the female screw portion 328 can be suppressed.

The upper portion of the shaft 246 is reduced in diameter, and the reduced diameter portion penetrates the bottom of the rotating shaft 326. An annular stopper 330 is fixed to the tip of the reduced diameter portion. On the other hand, a back spring 332 that biases the shaft 246 downward (in the valve closing direction) is interposed between the base end of the reduced diameter portion and the bottom of the rotating shaft 326. With such a configuration, when the valve portion 202 is opened, the shaft 246 and the rotor 320 are displaced integrally so that the stopper 330 is locked to the bottom of the rotary shaft 326. On the other hand, when the valve portion 202 is closed, the back spring 332 is compressed by the reaction force received by the valve element 204 from the valve seat 210. The valve body 204 can be pressed against the valve seat 210 by the elastic reaction force of the back spring 332 at this time, and the seating performance (valve closing performance) of the valve body 204 can be improved.

Annular seal members

206 and 201 are interposed between the 2 nd body 260 and the pipe body 2 and between the 1 st body 240 and the pipe body 2, respectively. With this configuration, the fluid is prevented from leaking through the gap between the pipe main body 2 and the 2 nd main body 260 and the gap between the 1 st main body 240 and the pipe main body 2. Further, an annular seal member 203 is interposed between the 1 st body 240 and the housing 400. With this configuration, outside air (moisture, etc.) is prevented from entering through the gap between the 1 st body 240 and the casing 400.

The bottom and large diameter portion 245 of the 1 st body 240 divide the interior of the valve body 200 and the interior of the motor unit 300. The pressure of the fluid is introduced into an internal space R formed by the inner surface of the housing 302, the bottom of the 1 st body 240, and the large diameter portion 245 through a flow path described later.

Fig. 2 is a cross-sectional view showing a fully opened state of the motor-operated valve 1.

The electric valve 1 has a stop mechanism that limits the translational movement of the rotation shaft 326. The stopper mechanism is composed of a part of the opening end of the rotating shaft 326, a 1 st protrusion 250, a 2 nd protrusion 252 and a stopper member 500 provided on the outer peripheral surface of the guide member 242.

The rotating shaft 326 has a diameter-enlarged portion 334 with an enlarged inner diameter at a lower portion. The diameter-enlarged portion 334 extends from just below the female screw portion 328 to the lower end of the rotary shaft 326. An opening end of the rotary shaft 326 protrudes downward of the rotor 320, and an annular recess 336 is provided along an outer peripheral surface thereof. The stopper member 500 is fitted in the recess 336.

On the outer peripheral surface of the guide member 242, a 1 st protrusion 250 is provided to protrude slightly below the male screw portion 244. Further below the 1 st projection 250, a 2 nd projection 252 is provided to project therefrom. The 1 st protrusion 250 is provided to protrude outward in the radial direction from the outer circumferential surface of the guide member 242. The height of the 1 st protrusion 250 is set to be lower than the height of the 2 nd protrusion 252. In embodiment 1, the 2 nd protrusion 252 forms an upper end portion of the large diameter portion 245. The 1 st protrusion 250 and the 2 nd protrusion 252 are integrally formed to the guide member 242. The 1 st protrusion 250 defines a top dead center in the translational movement of the rotation shaft 326, and the 2 nd protrusion 252 defines a bottom dead center.

When the screw feeding mechanism is operated by driving of the motor unit 300 and the rotary shaft 326 starts moving upward, the shaft 246 and the rotor 320 are displaced integrally. By this displacement, the spool 204 is disengaged from the valve seat 210. Accordingly, the fluid flowing into the inlet port 222, the inlet port 262, and the valve chamber 266 flows out through the outlet port 264 and the outlet port 224 in this order.

As shown in fig. 1, in the valve-closed state, a part of the opening end of the rotating shaft 326 abuts against the upper end (the 2 nd projection 252 in fig. 2) of the large diameter portion 245. On the other hand, as shown in fig. 2, in the fully open state, a part of the stopper member 500 abuts on the 1 st projection 250. The 2 abutment systems restrict translational movement to the lower side (valve closing direction) and the upper side (valve opening direction) of the rotating shaft 326.

Fig. 3 is an enlarged view of a portion a in fig. 1.

As explained in association with fig. 1, the guide member 242 slidably supports the shaft 246. Thus, a clearance Cl1 exists between the guide member 242 and the shaft 246. A pressure equalizing hole 243 is provided to communicate the inside and outside of the guide member 242. The pressure equalizing hole 243 is provided to open in the radial direction of the guide member 242, and introduces the pressure of the fluid into the internal space R. The fluid is introduced from the valve chamber 266 into the internal space R through the gap Cl1 and the pressure equalizing hole 243.

Fig. 4 is an enlarged view of a portion B in fig. 1.

In order for the screw feeding mechanism to function normally, a clearance called "backlash" needs to be provided between the external screw portion 244 and the internal screw portion 328. A clearance Cl2 (1 st clearance) is formed between the threads of the male screw portion 244 and the female screw portion 328. The fluid flows into the gap Cl2 between the guide member 242 and the rotation shaft 326. As shown in fig. 4, when the valve is closed, a clearance Cl2 is formed between the lower surface of the ridge of the female screw portion 328 and the upper surface of the ridge of the male screw portion 244. When the valve is opened, the clearance Cl2 is formed between the lower surface of the ridge of the male screw portion 244 and the upper surface of the ridge of the female screw portion 328. That is, one side surface of the ridge of the male screw portion 244 abuts one side surface of the ridge of the female screw portion 328. Further, a gap Cl2 is formed between the ridge of the male screw portion 244 and the ridge of the female screw portion 328 between surfaces opposite to the abutting surfaces.

Fig. 5 is an enlarged view of a portion C in fig. 1.

As described in connection with fig. 1, the rotor 320 moves in the axial direction inside the housing 302. To enable this movement, a gap Cl3 (No. 2 gap) is formed between the outer peripheral surface of the magnet 324 and the inner peripheral surface of the housing 302. The fluid introduced into the internal space R flows into the gap Cl 3.

Fig. 6 is an enlarged view of the X portion in fig. 1. In fig. 6, the arrows indicate the direction of fluid flow.

The fluid is introduced from the valve chamber 266 into the internal space R through the clearance Cl1 and the pressure equalizing hole 243. In the internal space R, the fluid also flows into the gaps Cl2, Cl 3. In the present embodiment, the gap Cl2 is set to be larger than the gap Cl1 and smaller than the gap Cl 3. That is, the clearance Cl3 is set to be larger than the clearance Cl 1.

In practice, the shaft 246 and the rotating shaft 326 can be eccentric with respect to the guide member 242. In the present embodiment, when the shaft 246 and the rotary shaft 326 are eccentric, the clearance Cl2 is set to be always larger than the gap Cl1 and smaller than the clearance Cl 3. That is, the clearance Cl3 is always set to be larger than the gap Cl 1.

More specifically, the shaft 246 and the rotating shaft 326 can be biased toward the guide member 242. In the present embodiment, the minimum value of the gap Cl2 is set to be larger than the maximum value of the gap Cl1 and smaller than the minimum value of the gap Cl 3. That is, the minimum value of the clearance Cl3 is set to be larger than the maximum value of the clearance Cl 1. The maximum value of the clearance Cl1 is the size of the clearance Cl1 on the opposite side to the radial direction of the guide member 242 when the shaft 246 is moved to the radial direction side. The minimum value of the clearance Cl2 is the size of the closer-side clearance Cl2 when the rotation shaft 326 is closer to the radial direction side of the guide member 242. The minimum value of the clearance Cl3 is the size of the closer-side clearance Cl3 when the rotation shaft 326 is closer to the radial direction side of the guide member 242.

As long as the minimum value of the clearance Cl2 is larger than the maximum value of the clearance Cl1, the clearance Cl2 is always larger than the clearance Cl1 regardless of the way in which the shaft 246 and the rotating shaft 326 are eccentric with respect to the guide member 242 (including the case in which no eccentricity occurs). Likewise, the gap Cl3 is always greater than the gap Cl1 as long as the minimum value of the gap Cl3 is greater than the maximum value of the gap Cl 1.

The fluid introduced from the gap Cl1 into the internal space R does not contain foreign matter (contaminants) larger than the maximum value of the gap Cl 1. Even if a foreign object smaller than the clearance Cl2 is caught by the clearance Cl2, the male screw portion 244 and the female screw portion 328 are less likely to be locked. By setting the minimum value of the gap Cl2 to be larger than the maximum value of the gap Cl1, it is possible to reduce the possibility that foreign matter is caught in the gap Cl2 and the screw feeding mechanism does not function.

In the present embodiment, the minimum value of the clearance Cl3 is set to be larger than the maximum value of the clearance Cl 1. As with the gap Cl2, foreign matter smaller than the gap Cl3 is less likely to lock the rotor 320 and the housing 302 in the gap Cl 3. By setting the minimum value of the gap Cl3 to be larger than the maximum value of the gap Cl1, it is possible to reduce the possibility that the foreign matter is caught by the gap Cl3 and obstructs the operation of the rotor 320.

As described in connection with fig. 4, in order for the screw feeding mechanism to function normally, it is necessary to provide backlash. However, the backlash may cause a fluctuation in the opening/closing switching of the motor-operated valve 1, which may reduce the accuracy of the motor-operated valve 1.

In this regard, in the motor-operated valve 1 of the present embodiment, the minimum value of the clearance Cl2 (see fig. 6) is set to be larger than the maximum value of the clearance Cl1, and as described in connection with fig. 1, the spring 216 is provided in the motor-operated valve 1. The spring 216 biases the shaft 246 in the valve closing direction. This biasing force can suppress the backlash generated between the male screw portion 244 and the female screw portion 328. Therefore, the accuracy of the motor-operated valve 1 can be prevented or suppressed from being lowered.

The minimum value of the clearance Cl3 is set to be larger than the maximum value of the clearance Cl1, but is preferably as small as possible. That is, the smaller the distance between the stator 340 and the rotor 320, the greater the torque that the stator 340 applies to the rotor 320. The greater the torque, the greater the thrust imparted by the rotor 320. In order to efficiently move the rotor 320 in the axial direction, the distance between the stator 340 and the rotor 320 is preferably as small as possible.

As described above, according to the present embodiment, the minimum value of the clearance Cl2 is set to be larger than the maximum value of the clearance Cl 1. With this configuration, only foreign matter smaller than the maximum value of the gap Cl1 is mixed into the fluid introduced into the gap Cl 2. Therefore, the possibility that the foreign matter is caught by the gap Cl2 to hinder the function of the screw feeding mechanism can be reduced

According to the present embodiment, the maximum value of the clearance Cl3 is set to be larger than the minimum value of the clearance Cl 1. This can reduce the possibility that the foreign matter will be caught by the gap Cl3 and hinder the operation of the rotor 320.

While the preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the specific embodiments, and various modifications can be made within the scope of the technical idea of the present invention.

In the above embodiment, the motor-operated valve in which the valve body is brought into contact with and separated from the valve seat and the valve portion is completely closed in the valve-closed state has been described. In the modification, a valve body may be inserted into and removed from a valve hole, such as a so-called spool valve, and the motor-operated valve may allow a small leakage of fluid in a closed state.

In the above embodiment, the motor-operated valve is configured as an electric expansion valve, but may be configured as an opening/closing valve or a flow rate control valve having no expansion function.

In the above embodiment, a description has been given of a mode in which the male screw portion is provided in the guide member that slidably supports the shaft, and the female screw portion is provided in the rotary shaft of the rotor. In the modification, a female screw portion may be provided on the guide member and a male screw portion may be provided on the rotary shaft of the rotor. That is, the screw feeding mechanism may be constituted by a guide portion that is erected on the main body, slidably supports the shaft, and has a female screw portion on an inner peripheral surface, and a guided portion that constitutes a rotation shaft of the rotor, has a male screw portion on an outer peripheral surface that is screwed into the female screw portion, and is supported so as to be inserted into the guide portion. The screw feeding mechanism may be constituted by a guide portion integral with the main body and a guided portion integral with the rotary shaft and the shaft of the rotor, and one of the guide portion and the guided portion may be inserted into the other. One of the male screw portions may be provided, and the other may be provided with the female screw portion. Either way, the screw feeding mechanism is located in the inner space.

In the above embodiment, the air gap Cl1 and the pressure equalizing hole 243 have been described as the flow path for introducing the fluid from the valve chamber into the internal space. In the modification, a gap for introducing the fluid from the valve chamber into the internal space may be provided in addition to the sliding portion of the shaft. In this case, the clearance Cl2 is sized to be larger than any gap.

In the above embodiment, the mode in which the minimum value of the gap Cl2 is smaller than the minimum value of the gap Cl3 is described. In a modification, the minimum value of the gap Cl2 may be about the same as the minimum value of the gap Cl 3. The minimum value of the gap Cl2 may be set to be larger than the minimum value of the gap Cl 3. In any case, if the minimum value of the clearance Cl2 is larger than the maximum value of the clearance Cl1, the possibility of the function of the screw feed mechanism being hindered can be reduced. Further, if the minimum value of the clearance Cl3 is larger than the maximum value of the clearance Cl1, the possibility of the rotor being hindered can be reduced.

In the above-described embodiment, a spring that is coaxial with the shaft is provided between the shaft and the guide member, and the spring biases the shaft so that the upper surface of the thread of the male screw portion abuts against the lower surface of the thread of the female screw portion. The spring may be a spring that generates a biasing force in a direction in which the lower surface of the ridge of the male screw portion abuts against the upper surface of the ridge of the female screw portion. That is, the spring only needs to generate an urging force in a direction in which the one side surface of the ridge of the external thread portion and the one side surface of the ridge of the internal thread portion are brought into contact with each other. Any arrangement may be used. For example, the shaft may be provided between the inner peripheral surface of the bottom of the housing and the upper end surface of the rotary shaft.

In the above embodiment, the valve body is integrally formed with the shaft. In the modification, the valve body and the shaft may be separate members and may be displaceable integrally. In this case, the valve element and the shaft may also be structurally integrated. Alternatively, the valve element and the shaft may be displaceable integrally and may be displaceable relative to each other. For example, as in the motor-operated valve described in japanese patent application laid-open No. 2016 and 205584, the valve body and the shaft may be displaced integrally when the valve is opened, and may be displaced relative to each other when the valve is closed.

In the above embodiment, the 1 st body 240 and the 2 nd body 260 are exemplified as the body (valve body) of the motor-operated valve, and the motor unit 300 is fixed to the 1 st body 240 and the 2 nd body 260 as the "motor-operated valve". In a modification, the pipe body 2, the 1 st body 240, and the 2 nd body 260 may be main bodies of the motor-operated valves, and the motor unit 300 may be fixed to these 3 main bodies to form the motor-operated valves.

The present invention is not limited to the above-described embodiments and modifications, and can be embodied by modifying the components without departing from the scope of the invention. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. Further, some of the components may be deleted from all the components shown in the above embodiments and modifications.

[ description of reference numerals ]

1 electric valve, 2 piping body, 200 valve body, 202 valve portion, 203 sealing member, 204 valve body, 206 sealing member, 208 valve hole, 210 valve seat, 212E ring, 214 spring bearing, 216 spring, 220 body, 222 inlet port, 224 outlet port, 240 st body, 1 st body, 242 guide member, 243 pressure equalizing hole, 244 external thread portion, 245 large diameter portion, 246 shaft, 248 spring bearing, 250 st protrusion, 252 nd protrusion, 260 nd body, 2 nd body, 262 inlet port, 264 outlet port, 266 valve chamber, 300 motor unit, 302 casing, 320 rotor, 322 rotor core, 324 magnet, 326 rotation shaft, 328 internal thread portion, 330 stopper, 332 back spring, 334 expanding portion, 336 recess, 340 stator, 342 lamination core, 344 bobbin, 345 coil unit, 346 coil, 400 casing, 402 terminal cover portion, 420 printed wiring board, 422 terminal,

cover

440, 500 stopper member, Cl1 gap, cl2 gap, Cl3 gap, R inner space, S space, U electric valve unit.

Claims

1. An electrically operated valve, comprising:

a main body provided with an inlet port for introducing a fluid from an upstream side, an outlet port for discharging the fluid to a downstream side, and a passage for communicating the inlet port with the outlet port,

a valve element that opens and closes a valve portion provided in the passage,

a rotor for driving the valve element in an opening/closing direction of the valve portion,

a shaft coaxially connected to the rotor and displaceable integrally with the valve body,

a housing which is a cylindrical member fixed to the main body and containing the rotor therein and which divides an internal space in which a pressure of the fluid acts and an external space in which the pressure of the fluid does not act,

a motor including the rotor and a stator coaxially externally inserted to the housing, an

A screw feeding mechanism which is located inside the housing and converts the rotational motion of the rotor into a translational motion;

a 1 st clearance is formed between the thread ridge of the male screw portion and the thread ridge of the female screw portion in the screw feeding mechanism,

the 1 st gap has a minimum value larger than a maximum value of a gap that communicates the internal space with the passage.

2. Electrically operated valve according to claim 1,

the screw feeding mechanism includes:

a guide portion erected on the body, slidably supporting the shaft, and provided with the male screw portion on an outer peripheral surface, an

And a guided portion that constitutes a rotation shaft of the rotor, has the female screw portion, which is screwed to the male screw portion, on an inner circumferential surface thereof, and is supported so as to be externally inserted into the guide portion.

3. Electrically operated valve according to claim 1,

the spring is also provided for urging the one side surface of the thread of the male screw portion and the one side surface of the thread of the female screw portion in a direction of abutting against each other.

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

and a 2 nd gap is arranged between the outer peripheral surface of the rotor and the inner peripheral surface of the shell, and the minimum value of the 2 nd gap is larger than the maximum value of the gap.