CN112483658B

CN112483658B - Electric valve

Info

Publication number: CN112483658B
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: 2023-12-22
Anticipated expiration: 2040-09-11
Also published as: CN112483658A; JP7266871B2; JP2021042820A

Abstract

Preventing or inhibiting the driving of the electric valve due to foreign matter mixed in the fluid. The electric valve includes: a body, a housing (302), a motor, and a screw feed mechanism. The body has an inlet port for introducing fluid from an upstream side, an outlet port for introducing fluid to a downstream side, and a passage for communicating the inlet port with the outlet port. The housing (302) divides an inner space (R) where the pressure of the fluid acts from an outer space where no pressure acts. 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 externally inserted to the housing (302). The screw feed mechanism is located inside the housing (302) and converts rotational movement of the rotor (320) into translational movement. A1 st clearance (Cl 2) is formed between the thread of the male thread part (244) and the thread of the female thread part (328) in the thread feeding mechanism, and the minimum value of the 1 st clearance (Cl 2) is larger than the maximum value of a clearance (Cl 1) for communicating the inner space (R) and the passage.

Description

Electric valve

Technical Field

The present disclosure relates to electrically operated valves, and more particularly to flow path configurations.

Background

An air conditioner for an automobile is generally configured by disposing 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 vaporous gas-liquid mixed refrigerant by receiving the flow, and sends the vaporous gas-liquid mixed refrigerant to the evaporator. As the expansion device, an electric expansion valve is used in which a motor is used in a driving portion to precisely control the valve opening. Such an electric expansion valve has a mechanism for bringing a valve body supported by the front end of a shaft into contact with and out of contact with a valve seat provided in a main body. A technique of converting a rotational motion of a rotor into a translational motion of a shaft by using a screw feed mechanism at the time of the contact/separation has been proposed.

Such an electric expansion valve is provided with a case fixed to a main body and isolating a rotor from the outside air. A refrigerant is introduced into an internal space formed inside the casing and containing the rotor and the screw feed mechanism. Conventionally, a refrigerant mixed with foreign matters flows into an inner space of a casing, and thus, a problem of preventing driving of a screw feeding mechanism occurs. In order to solve this problem, a technique of narrowing a flow path to an internal space to remove foreign matters contained in a refrigerant is known (for example, refer to patent document 1).

Prior art literature

Patent literature

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

Disclosure of Invention

[ problem to be solved by the invention ]

However, small foreign substances that can pass through a narrow flow path connected to the internal space may enter the screw portion of the screw feed mechanism. In the electric expansion valve, such a minute foreign matter bites into the screw portion, and may prevent the valve element from being driven. Such a problem is not limited to the electric expansion valve, and various electric valves may be similarly generated.

The present invention has been made in view of the above problems, and an object thereof is to prevent or suppress the interference of the driving of an electric valve due to foreign matter mixed in a fluid.

[ solution for solving the technical problem ]

One embodiment of the present invention is an electrically operated valve. The electric valve includes: a main body provided with an inlet port for introducing a fluid from an upstream side, an outlet port for introducing a 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/closing direction of the valve section; a shaft coaxially connected to the rotor and capable of being displaced integrally with the valve element; a housing which is a cylindrical member fixed to the main body and having a rotor therein, and which divides an inner space in which the pressure of the fluid acts and an outer space in which the pressure of the fluid does not act; a motor including a rotor and a stator coaxially externally inserted in the housing; and a screw feed mechanism located inside the housing, converting rotational movement of the rotor into translational movement. A1 st gap is formed between the thread of the male screw portion and the thread of the female screw portion in the screw feed mechanism. The minimum value of the 1 st gap is larger than the maximum value of the gap that communicates the internal space with the passage.

According to this aspect, the size of the foreign matter introduced into the internal space is smaller than the void. Further, by making the 1 st gap larger than the clearance, biting of the screw portion due to foreign matter introduced into the 1 st gap is prevented or suppressed. Therefore, the driving of the valve element in the motor-operated valve can be prevented or suppressed.

[ Effect of the invention ]

According to the present invention, it is possible to prevent or suppress the interference of the driving of the electric valve due to the foreign matter mixed in the fluid.

Drawings

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

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

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

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

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

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

Detailed Description

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, for convenience, the positional relationship of each structure may be expressed with reference to the illustrated state. In the following embodiments and modifications thereof, substantially the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate.

Embodiment(s)

Fig. 1 is a cross-sectional view showing the structure of an electrically operated valve unit U according to the embodiment. The electric valve unit U includes an electric valve 1 and a pipe body 2. The electric valve 1 is applied to a refrigeration cycle of an air conditioner for an automobile, not shown. The refrigeration cycle includes a compressor for compressing a circulating refrigerant, a condenser for condensing the compressed refrigerant, an expansion valve for throttle-expanding the condensed refrigerant and delivering the refrigerant in a mist form, an evaporator for evaporating the mist refrigerant and cooling air in a cabin by latent heat of evaporation thereof, and the like. The motor 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 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 configured 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 in the upper half of the pipe body 2. The 2 nd body 260 is disposed at the lower half of the 1 st body 240. The 2 nd body 260 is located inside the pipe body 2. The valve portion 202 is housed in the 2 nd main body 260. A guide member 242 (guide portion) is provided at the upper center of the 1 st main body 240. The guide member 242 is a machined product made of a metal material, and a male screw portion 244 is formed on the outer peripheral surface of the axial center portion of the guide member 242. The guide member 242 has a large diameter at its lower end portion, and the large diameter portion 245 is coaxially fixed to the upper center of the 1 st main body 240. A shaft 246 extending from the rotor 320 of the motor unit 300 is inserted inside the 1 st main body 240. The lower end portion of the shaft 246 doubles as the valve element 204 constituting the valve portion 202. The guide member 242 supports the shaft 246 in the axial direction by its inner peripheral surface in a slidable manner, and supports the rotary shaft 326 (guided portion) of the rotor 320 by its outer peripheral surface in a rotatable and slidable manner.

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

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

An E-ring 212 is fitted into the valve chamber 266 at the lower portion of the shaft 246. Above the E-ring 212 is a spring support 214. A spring support 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 supports 214, 248 coaxially with the valve body 204. In the present embodiment, the lower end of the shaft 246 also doubles as the valve body 204, so the spring 216 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 cylindrical case 302 having a bottom, a rotor 320 disposed inside the case 302, and a stator 340 disposed outside the case.

The stator 340 includes a laminated core 342 and a bobbin 344. The laminated core 342 is constituted by laminating plate-shaped 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 an upper end opening of the housing 400. The printed wiring board 420 is disposed in a space S surrounded by the case 400 and the cover 440. The coil 346 is connected to the printed wiring board 420. The case 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 an outer periphery of the rotor core 322. Rotor core 322 is assembled to rotary shaft 326. The magnet 324 is magnetized to be multipolar in the circumferential direction thereof.

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

As described above, the spring 216 biases the valve element 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 244 is brought into contact with the lower surface of the thread of the female screw 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 rotary 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 rotary shaft 326. With this 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 rotation 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, fluid is prevented from leaking through the gap between the pipe body 2 and the 2 nd body 260 and the gap between the 1 st body 240 and the pipe body 2. Further, an annular seal member 203 is interposed between the 1 st main body 240 and the housing 400. With this configuration, the intrusion of outside air (moisture, etc.) through the gap between the 1 st body 240 and the housing 400 is prevented.

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

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

The electric valve 1 has a stopper mechanism that restricts translational movement of the rotation shaft 326. The stopper mechanism is constituted by a 1 st projection 250, a 2 nd projection 252 and a stopper member 500 provided on the outer peripheral surface of the guide member 242 at a part of the opening end portion of the rotation shaft 326.

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

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

When the screw feed mechanism is operated by driving the motor unit 300 and the rotation shaft 326 starts to move upward, the shaft 246 is displaced integrally with the rotor 320. By this displacement, the valve element 204 is disengaged from the valve seat 210. Thus, 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 closed valve state, a part of the opening end portion of the rotation shaft 326 is in contact with the upper end portion (the 2 nd protrusion 252 in fig. 2) of the large diameter portion 245. On the other hand, as shown in fig. 2, in the fully opened state, a part of the stopper member 500 abuts against the 1 st projection 250. Translational movement below (in the valve closing direction) and above (in the valve opening direction) the rotation shaft 326 is restricted by these 2 abutment methods.

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. Therefore, a clearance C11 exists between the guide member 242 and the shaft 246. The equalizing hole 243 is provided so as to communicate the inside and outside of the guide member 242. The pressure equalizing hole 243 is provided so as to open in the radial direction of the guide member 242, and introduces the pressure of the fluid into the internal space R. Fluid is introduced from the valve chamber 266 to the internal space R through the clearance C11 and the pressure equalizing hole 243.

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

In order for the screw feed mechanism to function properly, a gap called "backlash" needs to be provided between the male screw portion 244 and the female screw portion 328. A clearance C12 (1 st clearance) is formed between the thread teeth of the male screw portion 244 and the female screw portion 328. Fluid flows into the gap C12 or between the guide member 242 and the rotating shaft 326. Further, as shown in fig. 4, when the valve is closed, a clearance C12 is formed between the lower surface of the thread of the female screw portion 328 and the upper surface of the thread of the male screw portion 244. When the valve is opened, a clearance C12 is formed between the lower surface of the thread of the male screw 244 and the upper surface of the thread of the female screw 328. That is, one side of the thread of the male screw 244 abuts one side of the thread of the female screw 328. A clearance C12 is formed between the thread of the male screw 244 and the thread of the female screw 328 on the opposite side of the contact surface.

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 C13 (a 2 nd 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 inner space R flows into the clearance C13.

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

Fluid is introduced from the valve chamber 266 into the internal space R through the clearance C11 and the pressure equalizing hole 243. In the inner space R, the fluid also flows into the gaps C12, C13. In the present embodiment, the gap C12 is set to be larger than the gap C11 and smaller than the gap C13. That is, the clearance C13 is set larger than the clearance C11.

In practice, the shaft 246 and the rotation shaft 326 can be eccentric with respect to the guide member 242. In the present embodiment, when the shaft 246 and the rotation shaft 326 are eccentric, the gap C12 is set to be always larger than the gap C11 and smaller than the gap C13. That is, the clearance C13 is set to be always larger than the clearance C11.

More specifically, the shaft 246 and the rotation shaft 326 can be biased toward the guide member 242. In the present embodiment, the minimum value of the gap C12 is set to be larger than the maximum value of the gap C11 and smaller than the minimum value of the gap C13. That is, the minimum value of the clearance C13 is set to be larger than the maximum value of the clearance C11. The maximum value of the clearance C11 here refers to the size of the clearance C11 on the opposite side of the shaft 246 when it is located on the radial side of the guide member 242. The minimum value of the clearance C12 is the size of the clearance C12 on the near side when the rotation shaft 326 is near the guide member 242 in the radial direction. The minimum value of the clearance C13 is the size of the clearance C13 on the near side when the rotation shaft 326 is near the guide member 242 in the radial direction.

As long as the minimum value of the clearance C12 is larger than the maximum value of the clearance C11, the clearance C12 is always larger than the clearance C11 regardless of the eccentric manner of the shaft 246 and the rotation shaft 326 with respect to the guide member 242 (including the case where the eccentricity does not occur). Similarly, as long as the minimum value of the gap C13 is greater than the maximum value of the gap C11, the gap C13 is always greater than the gap C11.

The fluid introduced from the space C11 into the internal space R does not contain foreign substances (contaminants) larger than the maximum value of the space C11. In addition, even if foreign matter smaller than the clearance C12 is caught in the clearance C12, the male screw 244 and the female screw 328 are less likely to be locked. By setting the minimum value of the clearance C12 to be larger than the maximum value of the clearance C11, the possibility that foreign matter is caught in the clearance C12 and the screw feed mechanism does not function can be reduced.

In the present embodiment, the minimum value of the clearance C13 is set to be larger than the maximum value of the clearance C11. As with the gap C12, foreign matter smaller than the gap C13 is less likely to lock the rotor 320 with the housing 302 in the gap C13. By setting the minimum value of the clearance C13 to be larger than the maximum value of the clearance C11, it is possible to reduce the possibility that foreign matter is caught in the clearance C13 and the operation of the rotor 320 is hindered.

As described in connection with fig. 4, a backlash is required to function normally in the screw feed mechanism. However, this backlash may cause rattling when switching the opening and closing of the motor-operated valve 1, which may reduce the accuracy of the motor-operated valve 1.

In this regard, in the electrically operated valve 1 of the present embodiment, the minimum value of the clearance C12 (see fig. 6) is set so as to be larger than the maximum value of the clearance C11, and as described in connection with fig. 1, the spring 216 is provided in the electrically operated valve 1. The spring 216 biases the shaft 246 in the valve closing direction. By this urging force, the rattling occurring between the male screw 244 and the female screw 328 can be suppressed. Therefore, a decrease in accuracy of the motor-operated valve 1 can be prevented or suppressed.

The minimum value of the clearance C13 is set to be larger than the maximum value of the clearance C11, 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 the stator 340 imparts to the rotor 320. The greater the torque, the greater the thrust imparted by rotor 320. In order to efficiently perform the movement of 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 C12 is set to be larger than the maximum value of the clearance C11. With this structure, only foreign matter smaller than the maximum value of the gap C11 is mixed into the fluid introduced into the gap C12. Therefore, the possibility that foreign matter is caught in the clearance C12 and the function of the screw feed mechanism is hindered can be reduced

According to the present embodiment, the maximum value of the clearance C13 is set to be larger than the minimum value of the clearance C11. This reduces the possibility that foreign matter is caught in the clearance C13 and obstructs the operation of the rotor 320.

While the preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various modifications are possible within the scope of the technical idea of the present invention.

In the above embodiment, the electrically operated valve in which the valve element is in contact with/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 a valve hole as a so-called spool valve, and an electric valve may be used that allows a minute leakage of fluid in a closed state.

In the above embodiment, the electric valve is an electric expansion valve, but may be an on-off valve or a flow control valve having no expansion function.

In the above embodiment, the description has been made of the manner in which the male screw portion is provided on the guide member that slidably supports the shaft, and the female screw portion is provided on the rotating shaft of the rotor. In the modification, the guide member may be provided with a female screw portion and the rotary shaft of the rotor may be provided with a male screw portion. That is, the screw feed mechanism may be constituted by a guide portion provided on the main body so as to slidably support the shaft and provided with a female screw portion on the inner peripheral surface, and a guided portion constituting the rotary shaft of the rotor and provided with a male screw portion on the outer peripheral surface to be screwed with the female screw portion and supported so as to be inserted into the guide portion. The screw feed mechanism may be constituted by a guide portion integral with the main body and a guided portion integral with the rotation 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 two may be provided with an external screw thread portion and the other may be provided with an internal screw thread portion. In either case, the screw feed mechanism is located in the interior space.

In the above embodiment, the clearance C11 and the pressure equalizing hole 243 are described as the flow path for introducing the fluid from the valve chamber to the internal space. In the modification, a space for introducing 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 size of the clearance C12 is set to be larger than any void.

In the above embodiment, the manner in which the minimum value of the gap C12 is smaller than the minimum value of the gap C13 is described. In the modification, the minimum value of the gap C12 may be the same size as the minimum value of the gap C13. The minimum value of the clearance C12 may be set larger than the minimum value of the clearance C13. In any case, as long as the minimum value of the clearance C12 is larger than the maximum value of the clearance C11, the possibility of obstructing the function of the screw feed mechanism can be reduced. Further, if the minimum value of the clearance C13 is larger than the maximum value of the clearance C11, the possibility of causing an obstacle to the operation of the rotor can be reduced.

In the above embodiment, a spring 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 configured to generate a force in a direction to bring the lower surface of the thread of the male screw portion into contact with the upper surface of the thread of the female screw portion. That is, the spring may generate a force in a direction to bring one side surface of the thread of the male screw portion into contact with one side surface of the thread of the female screw portion. The arrangement may be arbitrary. For example, the inner peripheral surface in the bottom of the housing and the upper end surface of the rotary shaft may be provided therebetween.

In the above embodiment, the valve body and the shaft are integrally formed. In the modification, the valve body and the shaft may be different members and may be integrally displaceable. In this case, the valve element and the shaft may be structurally integrated. Alternatively, the valve body and the shaft may be displaceable integrally and relatively. For example, as in an electric valve described in japanese patent application laid-open publication 2016-205584, the valve body and the shaft may be displaced integrally when the valve is opened, and the valve body may be displaced relatively when the valve is closed.

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

The present invention is not limited to the above-described embodiments and modifications, and the constituent elements may be modified and embodied within a range not departing from the gist of the present invention. Various inventions may be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments and modifications. In addition, some components may be deleted from all components shown in the above embodiments and modifications.

[ description of reference numerals ]

An electrically operated valve, a 2 pipe body, a 200 valve body, a 202 valve part, a 203 sealing member, a 204 valve core, a 206 sealing member, a 208 valve hole, a 210 valve seat, a 212E-ring, a 214 spring, a 216 spring, a 220 body, a 222 inlet port, a 224 outlet port, a 240 1 st body, a 242 member, a 243 equalizing member, a 244 male screw part, a 245 large diameter part, a 246 shaft, a 248 spring support, a 250 1 st protrusion, a 252 nd protrusion, a 260 nd body, a 262 inlet port, a 264 outlet port, a 266 valve chamber, a 300 motor unit, a 302 housing, a 320 rotor, a 322 rotor core, a 324 magnet, a 326 rotary shaft, a 328 female screw part, a 330 stopper, a 332 back spring, a 334 expanded diameter part, a 336 recess, a 340 stator, a 342 laminated core, a 344 bobbin, a 345 coil unit, a 346 coil, a 400 housing, a 402 terminal cover part, a 420 printed wiring board, a 422 terminal, a 440 cover, a 500 stopper member, a C11 void, a 12 gap, a C13 gap, an R interior space, an S space, and a U electrically operated 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 introducing a fluid to a downstream side, and a passage for communicating the inlet port with the outlet port,

a valve body which opens and closes a valve portion provided in the passage,

a rotor for driving the valve element in the 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, and which divides an inner space in which a pressure of a fluid acts and an outer space in which the pressure does not act,

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

A screw feed mechanism located inside the housing, converting rotational movement of the rotor into translational movement;

a 1 st gap is formed between the thread of the external thread part and the thread of the internal thread part in the thread feeding mechanism,

the minimum value of the 1 st gap is larger than the maximum value of the gap communicating the internal space with the passage.

2. The electrically operated valve as set forth in claim 1, wherein,

the screw feed mechanism has:

a guide portion standing on the main body and slidably supporting the shaft, the guide portion being provided with the male screw portion on an outer peripheral surface thereof, and

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

3. The electrically operated valve as set forth in claim 1, wherein,

the screw has a spring for biasing the one side surface of the thread of the male screw against the one side surface of the thread of the female screw.

4. An electrically operated valve as claimed in any one of claims 1 to 3, characterized in that,

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