CN111742169A

CN111742169A - Electric valve

Info

Publication number: CN111742169A
Application number: CN201980014366.5A
Authority: CN
Inventors: 荒井良太
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2018-02-20
Filing date: 2019-01-11
Publication date: 2020-10-02
Anticipated expiration: 2039-01-11
Also published as: WO2019163319A1; CN111742169B; JP2019143704A; JP6902789B2

Abstract

Provided is a highly reliable electrically operated valve in which foreign matter contained in a fluid (refrigerant) flowing therethrough can be strongly pressed against a valve element and a valve seat without being caught between the valve element and the valve seat, whereby scratches, and the like can be prevented from being generated in the valve seat and the valve element, and valve leakage can be prevented from occurring. An electrically operated valve (1) for converting the rotation of a rotor (57) into the vertical movement of a main valve element (20) by a screw feed mechanism, wherein a sub valve element (30) for opening and closing a valve port (9) is disposed around the main valve element (20) so as to be movable vertically, and when the main valve element (20) closes the valve port (9), the sub valve element (30) closes the valve port (9) prior to the main valve element (20).

Description

Electric valve

Technical Field

The present invention relates to an electrically operated valve suitable for use in a heat pump type cooling/heating system or the like, and more particularly to an electrically operated valve in which a defect is unlikely to occur due to foreign matter such as metal powder contained in a fluid (refrigerant) flowing therethrough.

Background

Conventionally, as an electrically operated valve, the following structure is known: the structure has: a valve body provided with a valve chamber, a plurality of inlets and outlets, a valve seat, a valve port, and the like; a valve body disposed in the valve chamber so as to be movable up and down; a screw feed mechanism for bringing the valve body into contact with and away from the valve seat, the screw feed mechanism being constituted by, for example, a valve shaft provided with an external thread and a guide rod provided with an internal thread; a cylindrical housing in sealing engagement with the valve body; and a stepping motor including a rotor rotatably disposed inside the housing and a stator disposed outside the housing, the stepping motor converting rotation of the rotor into vertical movement of the valve body by a screw feed mechanism to change an amount of lift (valve opening degree) of the valve body, thereby adjusting a flow rate of a fluid (refrigerant) passing through the valve port (see, for example, patent document 1).

In this motor-operated valve, the rotation of the rotor is generally transmitted to the screw feed mechanism without being reduced in speed (this type is referred to as a direct-drive motor-operated valve), but in recent years, as shown in patent document 2, for example, in order to increase the sealing pressure, a planetary gear type reduction mechanism is interposed between the rotor and the screw feed mechanism, and the rotation of the rotor is reduced in speed and transmitted to the screw feed mechanism, thereby increasing the axial force of the valve body, that is, the pressing force of the valve body against the valve seat (this type is referred to as a gear reduction motor-operated valve).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2012-172749

Patent document 2: japanese patent laid-open publication No. 2013-130271

Technical problem to be solved by the invention

However, in the conventional motor-operated valve as described above, when the amount of lift of the valve element is small (slight opening), foreign matter (metal powder, cutting slag, abrasive, slurry (japanese patent: スラッジ), etc.) contained in the fluid (refrigerant) tends to block the valve element portion, and when the valve is closed from this slight opening state, the foreign matter having a tendency to block is caught between the valve element and the valve seat, and there is a problem that the valve is liable to leak due to the foreign matter being caught.

In particular, in a gear-reduction-type motor-operated valve in which the pressing force of the valve element against the valve seat is increased, if a foreign object is caught between the valve element and the valve seat during valve closing, the foreign object caught is strongly pressed against the valve seat by the valve element, and therefore scratches, or the like are generated on (the sealing surface of) the valve seat and the valve element, and valve leakage is likely to occur.

Therefore, conventionally, when the gear-reduction type electrically operated valve as described above is used as, for example, an emergency shutoff valve, two electrically operated valves are connected in series for the purpose of improving safety, but in this measure, when considering a valve, a pipe, and the like incorporated in a system, the cost is significantly increased as compared with a case where only one electrically operated valve is used, and there is a possibility that a foreign object bites into itself, which is not preferable in terms of cost performance.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a highly reliable motor-operated valve that can be strongly pressed against a valve element and a valve seat without causing foreign matter contained in a fluid (refrigerant) to be flowed between the valve element and the valve seat, thereby preventing the valve seat and the valve element from being scratched or scratched and making it difficult to cause valve leakage.

Means for solving the problems

In order to achieve the above object, an electrically operated valve according to the present invention basically comprises: a valve body provided with a valve chamber, a plurality of inlets and outlets, and a valve port; a main valve body disposed in the valve chamber so as to be movable up and down, the main valve body opening and closing the valve port; a cylindrical housing joined to the valve main body; a stepping motor including a rotor and a stator, the rotor being rotatably disposed inside the housing, the stator being disposed outside the housing; and a screw feed mechanism that converts rotation of the rotor into vertical movement of the main valve element, and a sub valve element that opens and closes the valve port is disposed on the main valve element so as to be vertically movable, and when the main valve element closes the valve port, the sub valve element closes the valve port prior to the main valve element.

In a preferred aspect, a main valve seat and a sub valve seat are separately provided at the valve port in the valve body, the main valve element is in contact with and separated from the main valve seat, and the sub valve element is in contact with and separated from the sub valve seat.

In a more preferred aspect, the main valve body moves up and down in a vertical direction with respect to the main valve seat to open and close the valve port, and the sub valve body moves up and down in a vertical direction with respect to the sub valve seat to open and close the valve port.

In another preferred embodiment, the sub-valve body is disposed on the main valve body so as to be slidable in the vertical direction and to be locked so as to be prevented from coming off.

In another preferred embodiment, the sub-valve body is disposed on an outer peripheral side of the main valve body so as to be movable up and down.

In another preferred embodiment, the sub-valve body is disposed on an inner peripheral side of the main valve body so as to be movable up and down.

In a more preferred aspect, the main valve element is provided with an upper flange portion serving as both a disengagement prevention portion and a spring receiving portion, and a cylindrical sub valve element having a lower flange portion is slidably inserted outside on the lower side of the upper flange portion, and a cylindrical disengagement prevention member is disposed on the outer peripheral side of the sub valve element, the cylindrical disengagement prevention member being provided with an inner flange-shaped hooking portion that engages with the upper flange portion and is fixedly attached to the lower flange portion, and a compression coil spring that biases the sub valve element in the valve closing direction is compressively attached between the upper flange portion and the lower flange portion.

In a more preferred embodiment, the main valve element has: a main valve element portion having a large diameter, the main valve element portion opening and closing the valve port; and a small-diameter body portion located above the main valve element portion, the sub valve element including: a large diameter outer insertion portion slidably or interstitially inserted in the main valve body portion; a small-diameter external insertion portion which is slidably externally inserted into the body portion; and a step portion between the large-diameter outer insertion portion and the small-diameter outer insertion portion, the step portion serving as a disengagement prevention portion and a spring receiving portion, wherein a compression coil spring is compressively attached between the step portion and a stationary portion provided on the valve main body above the step portion, and the compression coil spring biases the sub-valve body in a valve closing direction.

In a more preferred aspect, the main valve body includes a cylindrical main valve body portion, the sub valve body is slidably disposed on an inner peripheral side of the main valve body portion, and is locked in a locking portion provided in the main valve body so as to be locked in a locking manner, and a compression coil spring is compression-mounted between the sub valve body and the main valve body, and biases the sub valve body in a valve closing direction.

In a more preferred aspect, the sub-valve body is slidably inserted outside a sub-valve body support rod having the anti-sticking portion fixedly attached to the main valve body.

In a more preferred aspect, the sub-valve body is slidably inserted into a cylindrical body portion having the main valve body and the anti-separation portion.

In another preferred aspect, a planetary gear type speed reduction mechanism is provided between the rotor and the screw feed mechanism.

Effects of the invention

In the motor-operated valve of the present invention, since the main valve element is provided with the sub valve element that closes the valve port prior to the main valve element, when the sub valve element is in a slightly opened state, foreign matter contained in the fluid (refrigerant) is blocked by the sub valve element, and when the sub valve element closes from there, the fluid (refrigerant) does not substantially flow, and therefore the foreign matter is not caught between the main valve element and the main valve seat, and therefore, even if the main valve element closes and is strongly pressed against the main valve seat, scratches, and the like do not occur in the main valve element and the main valve seat.

Further, although there is a possibility that foreign matter may bite into between the sub-valve body and the sub-valve seat, the sub-valve body is biased only by the compression coil spring, and therefore the pressing force is not so strong, and therefore, scratches, or the like do not occur between the sub-valve body and the sub-valve seat.

Further, even if foreign matter bites into a gap between the sub-valve body and the sub-valve seat to generate a gap therebetween, the main valve body closes, and therefore, valve leakage does not occur.

As described above, according to the present invention, it is possible to prevent foreign matter contained in the fluid (refrigerant) from being caught between the main valve element and the main valve seat and being strongly pressed against the main valve element and the main valve seat, and therefore, it is possible to prevent scratches, and the like from occurring in the valve seat and the valve element. As a result, valve leakage can be effectively prevented and reliability of the closed valve can be improved.

Drawings

Fig. 1 is an overall vertical cross-sectional view illustrating a fully closed state of a first embodiment of an electrically operated valve according to the present invention.

Fig. 2 is an enlarged longitudinal sectional view of a main portion of the electric valve shown in fig. 1.

Fig. 3 is an enlarged vertical cross-sectional view of a main portion for explaining a valve closing operation period (1) at the time of the first flow in the motor-operated valve of the first embodiment.

Fig. 4 is a longitudinal cross-sectional view of a main part for explaining a valve closing operation period (2) in the first flow in the motor-operated valve of the first embodiment.

Fig. 5 is a vertically enlarged partial cross-sectional view for explaining the completion (full closing) of the valve closing operation at the time of the first flow in the motor-operated valve according to the first embodiment.

Fig. 6 is an enlarged vertical cross-sectional view of a main portion of the motor-operated valve of the first embodiment for explaining a valve opening operation period in the first flow.

Fig. 7 is an enlarged vertical cross-sectional view of a main portion for explaining a valve closing operation period (1) in the second flow in the motor-operated valve of the first embodiment.

Fig. 8 is an enlarged vertical cross-sectional view of a main part of the motor-operated valve of the first embodiment for explaining a valve closing operation period (2) in the second flow.

Fig. 9 is an overall vertical cross-sectional view illustrating a fully closed state of the electrically operated valve according to the second embodiment of the present invention.

Fig. 10 is an enlarged vertical cross-sectional view of a main part for explaining a valve closing operation period (1) in the first flow in the motor-operated valve of the second embodiment.

Fig. 11 is an enlarged vertical cross-sectional view of a main part of the motor-operated valve of the second embodiment for explaining a valve closing operation period (2) in the first flow.

Fig. 12 is a vertically enlarged partial cross-sectional view for explaining the completion (full closing) of the valve closing operation at the time of the first flow in the motor-operated valve according to the second embodiment.

Fig. 13 is an enlarged vertical cross-sectional view of a main part of the motor-operated valve of the second embodiment for explaining a valve opening operation period in the first flow.

Fig. 14 is an enlarged vertical cross-sectional view of a principal part of a third embodiment of a motor-operated valve according to the present invention for explaining a valve closing operation period (1) in the first flow in the motor-operated valve according to the third embodiment.

Fig. 15 is a longitudinal cross-sectional view of an essential part for explaining a valve closing operation period (2) in the first flow in the motor-operated valve of the third embodiment.

Fig. 16 is a vertically enlarged partial cross-sectional view for explaining the completion (full closing) of the valve closing operation at the time of the first flow in the motor-operated valve according to the third embodiment.

Fig. 17 is a longitudinal sectional view of a main part for explaining a valve opening operation period in the first flow in the motor-operated valve of the third embodiment.

Fig. 18 is a longitudinal cross-sectional view of a principal portion of another example (fully closed state) of the third embodiment of the motor-operated valve of the present invention.

Fig. 19 is an overall vertical cross-sectional view illustrating a fully closed state of the fourth embodiment of the motor-operated valve of the present invention.

Fig. 20 is a longitudinal cross-sectional view of an essential part for explaining a valve closing operation period (1) in the first flow in the motor-operated valve of the fourth embodiment.

Fig. 21 is a longitudinal cross-sectional view of an essential part for explaining a valve closing operation period (2) in the first flow in the motor-operated valve of the fourth embodiment.

Fig. 22 is a vertically enlarged partial cross-sectional view for explaining the completion (full closing) of the valve closing operation at the time of the first flow in the motor-operated valve according to the fourth embodiment.

Fig. 23 is a longitudinal cross-sectional view of a main part of the motor-operated valve of the fourth embodiment for explaining a valve opening operation period in the first flow.

Fig. 24 is an enlarged vertical cross-sectional view of a main part of a fifth embodiment of an electrically operated valve according to the present invention for explaining a valve closing operation period (1) in a first flow in the electrically operated valve according to the fifth embodiment.

Fig. 25 is a vertically enlarged partial cross-sectional view of the motor-operated valve of the fifth embodiment for explaining a valve closing operation period (2) in the first flow.

Fig. 26 is a vertically enlarged partial cross-sectional view for explaining the completion (full closing) of the valve closing operation at the time of the first flow in the motor-operated valve according to the fifth embodiment.

Fig. 27 is a vertically enlarged partial cross-sectional view of the motor-operated valve of the fifth embodiment for explaining the valve opening operation period in the first flow.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[ first embodiment ]

Fig. 1 is an overall vertical cross-sectional view showing a fully closed state of a first embodiment of an electrically operated valve according to the present invention, and fig. 2 is an enlarged vertical cross-sectional view of a main portion of the electrically operated valve shown in fig. 1. Fig. 3 to 8 are enlarged vertical sectional views of essential parts for explaining the structure and operation of the motor-operated valve shown in fig. 1 and 2.

In the present specification, the description of the position and direction such as up and down, left and right, front and back, etc. is given for convenience of the drawings in order to avoid the complexity of the description, and is not limited to the description of the position and direction in the state of being actually incorporated into the system.

In the drawings, gaps formed between members, a distance between members, and the like may be drawn larger or smaller than the size of each structural member for convenience of drawing and for convenience of understanding of the invention.

The motor-operated valve 1 of the illustrated embodiment is suitable for use as, for example, an expansion valve in a heat pump type cooling and heating system, and therefore causes a fluid (refrigerant) to flow in both directions (a first flow direction from the lateral direction downward and a second flow direction from the downward direction lateral direction). As will be described later, the motor-operated valve 1 of the present embodiment is configured to improve the axial force of the main valve body and to improve the sealing performance by interposing a planetary gear type reduction mechanism between the rotor and the screw feed mechanism.

The electric valve 1 includes: a valve main body 10, the valve main body 10 having a bottomed cylindrical base body 10A made of sheet metal; a main poppet 20, the main poppet 20 being disposed in the valve body 10 so as to be movable up and down; and a step motor 50, the step motor 50 being installed at an upper side of the valve body 10 in order to move the main spool 20 up and down.

A valve chamber 7 is formed in a tubular base body 10A of a valve main body 10, a lateral first inlet/outlet (conduit joint) 11 opening to the valve chamber 7 is attached to a side portion of the tubular base body 10A, a stepped valve seat member 8 is fixed to a bottom portion of the tubular base body 10A, the valve seat member 8 is formed with a vertical valve port 9 opening from below to the valve chamber 7, a main valve seat 8a formed by an upper end inner peripheral corner portion of the valve port 9, and a sub valve seat 8b formed by an upper outer peripheral conical land of the valve port 9, and a second inlet/outlet (conduit joint) 12 connected to the valve port 9 is attached to the valve seat member 8.

A stepped tubular base 13 is attached to an upper surface opening of the tubular base 10A, and a lower end portion of a cylindrical case 58 with a top portion constituting a part of the stepping motor 50 is hermetically joined to an upper end portion of the tubular base 13 by welding or the like. The cylindrical holding member 14 with the partition wall 14c is fixed to the inner peripheral side of the cylindrical base 13 by press fitting or the like, and the bearing member 15 having the female screw 15i provided on the lower inner periphery is fixed to the upper portion of the cylindrical holding member 14 by caulking. A spring chamber 14a in which a valve opening spring 25 made of a compression coil spring is housed is provided directly above the partition wall 14c of the cylindrical holding member 14.

The main valve element 20 has a stepped cylindrical shape, and is a poppet valve that moves vertically in a vertical direction with respect to the main valve seat 8a to open and close the valve port 9. Referring to fig. 2, main poppet 20 includes: a main valve body 20A having a slightly larger diameter, the main valve body 20A being in contact with and separated from the main valve seat 8a of the valve seat member 8 to open and close the valve port 9; and a body portion 20B located above the main valve portion 20A, wherein an upper portion of the body portion 20B is slidably fitted into a valve body guide hole 14B located below the partition wall 14c in the tubular holding member 14. In order to obtain a required sealing property, an inverted conical sealing surface 20A that comes into substantially line contact with the main valve seat 8a is provided on the outer peripheral portion of the lower surface of the main valve element 20A.

In the present embodiment, a sub-valve body 30 for opening and closing the valve port 9 is disposed on the lower outer peripheral side of the main valve body 20 so as to be slidable in the vertical direction. That is, as described above, the main valve seat 8a that is in contact with (the sealing surface 20A of) the main valve body 20A is provided on the upper inner peripheral side (the corner portion) of the seat member 8 (the valve port 9) in the valve main body 10, and the sub valve seat 8b having a truncated conical shape that is in contact with and separated from the sealing surface (the lower end inner peripheral side corner portion) 30A of the sub valve body 30 is provided on the upper outer peripheral side of the seat member 8 apart from the main valve seat 8 a. The sub-valve body 30 has a cylindrical portion 30A slidably inserted on the outer periphery of the lower portion of the main valve body 20, and (a sealing surface (lower end inner peripheral side corner portion) 30A of) the cylindrical portion 30A moves vertically with respect to the sub-valve seat 8b to open and close the valve port 9.

More specifically, the main valve element 20A is provided with an upper flange 20C serving as both a locking prevention portion and a spring receiving portion (specifically, an upper surface is a locking prevention portion and a lower surface is a spring receiving portion), and a cylindrical sub valve element 30 (in other words, a cylindrical sub valve element 30A having a lower flange 30B) having a lower flange 30B is slidably inserted to the outside of the lower side of the upper flange 20C. A cylindrical retaining member 32 is disposed on the outer peripheral side of the sub-valve body 30, the cylindrical retaining member 32 is provided at its upper end with an inner flange-shaped hooking portion 32B that engages with the upper flange-shaped portion 20C, and is fixed at its lower end to the outer peripheral portion of the upper surface of the lower flange-shaped portion 30B by welding or the like, a compression coil spring 33 as an urging member is compression-mounted between (the lower surface of) the upper flange-shaped portion 20C and (the upper surface of) the lower flange-shaped portion 30B, and the compression coil spring 33 constantly urges the sub-valve body 30 downward (in the valve closing direction).

An O-ring 34 as a seal member is interposed between the cylindrical portion 32A of the cylindrical retaining member 32 and the upper flange portion 20C (specifically, an annular groove formed on the outer periphery of the upper flange portion 20C).

The dimensions and shapes of the respective portions of the sub-spool 30 are set to: when main valve element 20 is closed from the open state, port 9 is closed prior to main valve element 20 (described in detail later).

On the other hand, the stepping motor 50 disposed on the upper side of (the cylindrical base body 10A of) the valve main body 10 includes a stator 55 and a rotor 57, the stator 55 has two-phase coil portions formed of a yoke 51, a bobbin 52, a coil 53, a resin mold 54, and the like, and is fitted and fixed to a housing 58, the rotor 57 is rotatably disposed in the housing 58, and a rotor support member 56 is fixed to the upper inner side of the rotor 57. Further, a reduction gear mechanism 40 of a singular planetary gear type is provided on the inner peripheral side of the rotor 57, and the reduction gear mechanism 40 of a singular planetary gear type includes the following components: a sun gear 41, the sun gear 41 being provided integrally with the rotor support member 56; a fixed ring gear 47, the fixed ring gear 47 being fixed to the distal end of the cylindrical body 14d, the cylindrical body 14d being fixedly attached to the upper end of the cylindrical holding member 14; a planetary gear 42, the planetary gear 42 meshing with the sun gear 41 and the fixed ring gear 47; a carrier 44, the carrier 44 rotatably supporting the planetary gear 42; an annular output gear 45, the output gear 45 meshing with the planetary gears 42; and an output shaft 46, the output shaft 46 being fixedly attached to the output gear 45. The number of teeth of the fixed ring gear 47 is set to be different from that of the output gear 45.

A lower portion of the support shaft 49 is inserted through a hole provided in an upper portion of the output shaft 46, and the carrier 44 and the sun gear 41 (rotor support member 56) are inserted through the support shaft 49.

A support member 48 is disposed inside the housing 58 between the top of the housing 58 and the rotor support member 56, the support member 48 has a diameter substantially equal to the inner diameter of the housing 58, and the upper portion of the support shaft 49 is inserted through a hole provided in the center portion of the support member 48.

An output shaft 46 of the singular planetary gear type reduction mechanism 40 is rotatably fitted to an upper portion of the bearing member 15, rotation of the output shaft 46 is transmitted to the rotating up-down movement shaft 17, and the rotating up-down movement shaft 17 is provided with a male screw 17e screwed with a female screw 15i provided in the bearing member 15. A slit-shaped fitting portion 46a is provided at a lower portion of the output shaft 46, a plate-shaped portion 17a is provided at an upper portion of the rotating vertical shaft 17 in a protruding manner, the plate-shaped portion 17a is slidably fitted to the slit-shaped fitting portion 46a, and when the output shaft 46 rotates, the rotating vertical shaft 17 rotates while moving vertically by the screw feed of the female screw 15i and the male screw 17 e.

A stepped, tubular thrust transmission member 23 is disposed below the rotating vertically moving shaft 17, and downward thrust of the rotating vertically moving shaft 17 is transmitted to the thrust transmission member 23 via the balls 18 and the ball bearings 19. Further, even if the rotating up-and-down shaft 17 descends while rotating by interposing the balls 18, only the downward thrust is transmitted from the rotating up-and-down shaft 17 to the thrust transmission member 23, and no rotational force is transmitted.

The thrust transmission member 23 is composed of, in order from top to bottom, a large diameter upper portion 23a, an intermediate body portion 23b, and a small diameter lower portion 23c, the ball bearing 19 is fitted into the inner periphery of the large diameter upper portion 23a, the partition wall 14c of the cylindrical holding member 14 is slidably inserted into the intermediate body portion 23b, the diameter of the small diameter lower portion 23c is smaller than that of the intermediate body portion 23b, and a through hole 26d constituting an upper portion of a pressure equalizing passage 26 described later and a plurality of lateral holes 26e opening to a back pressure chamber 27 described later are provided in the thrust transmission member 23. The upper end opening of the through hole 26d is closed by the ball bearing 19.

The small-diameter lower portion 23c of the thrust transmission member 23 is fitted and fixed to the upper fitting hole 20d of the stepped cylindrical main valve element 20 by press fitting or the like, and the main valve element 20 and the thrust transmission member 23 move up and down integrally. Between the upper end surface of the main valve element 20 and the lower end step portion of the intermediate body portion 23b of the thrust transmission member 23, the pressing member 24 is sandwiched and fixed at the time of press-fitting of the small diameter lower portion 23c, and a seal member 29 made of an O-ring or an annular gasket is attached between an annular groove provided at the upper end portions of the pressing member 24 and the main valve element 20 and the valve element guide hole 14b of the cylindrical holding member 14.

Further, a valve-opening spring 25 made of a compression coil spring is attached in a compressed state to a spring chamber 14a on the upper side of the partition wall 14c of the cylindrical holding member 14 in a state where the lower end thereof is in contact with the partition wall 14c, and a pull-up spring receiving body 28 having flange-like hooking portions (an upper hooking portion 28a, a lower hooking portion 28b) on the upper and lower sides is disposed in the spring chamber 14a in order to transmit the biasing force (pull-up force) of the valve-opening spring 25 to the main valve body 20 via the thrust transmitting member 23. The upper hook portion 28a of the pull-up spring receiver 28 is placed above the valve opening spring 25, and the lower hook portion 28b is hooked to the lower end step portion of the large diameter upper portion 23a of the thrust transmission member 23.

Therefore, in the present embodiment, the screw feed mechanism is constituted by the bearing member 15 provided with the female screw 15i and the rotating up-down shaft 17 provided with the male screw 17e, and the like, and when the stepping motor 50 (the rotor 57) is rotated in one direction, the rotating up-down shaft 17 is rotated, for example, downward while being transmitted by the threads of the female screw 15i and the male screw 17e, and the thrust transmission member 23 and the main spool 20 are pressed down against the urging force of the valve opening spring 25 by the thrust of the rotating up-down shaft 17, and finally the sealing surface 20A of the main spool portion 20A is pressed against the main valve seat 8a, and the valve port 9 is closed.

On the other hand, when the stepping motor 50 (rotor 57) is rotated in the other direction, the rotary up-down shaft 17 moves up, for example, while rotating by the screw transmission of the female screw 15i and the male screw 17e, and accordingly, the thrust transmission member 23 and the main valve element 20 are pulled up by the biasing force of the valve opening spring 25, and the seal surface 20A of the main valve element portion 20A rises (lift) from the main valve seat 8a to open the valve port 9.

The following description includes a detailed operation of the sub-valve body 30.

In the present embodiment, a back pressure chamber 27 is defined between the pressing member 24 above the main valve element 20 and the partition wall 14c of the cylindrical holding member 14. Further, a stepped pressure equalizing passage 26 is provided in the main valve body 20 to communicate a tip end portion (lower end portion) of the main valve body 20 with a back pressure chamber 27. The pressure equalizing passage 26 communicates with the back pressure chamber 27 together with the vertical holes 26d and the horizontal holes 26e of the thrust transmission member 23. Here, the chamber diameter Da of the back pressure chamber 27 and the bore Dc of the valve port 9 are set to be substantially the same so that the downward pressure (force acting in the valve closing direction) acting on the main valve element 20 in the valve closed state is balanced (differential pressure is cancelled) with the upward pressure (force acting in the valve opening direction) acting on the main valve element 20.

Next, the opening and closing operation including the sub valve body 30 in the motor-operated valve 1 having the above-described configuration will be described with reference to fig. 2 to 8.

First, as shown in fig. 2 and 5, when the valve closing operation is completed and the main valve body 20 and the sub-valve body 30 are positioned at the lowermost position, that is, when the main valve body 20 is seated on and pressed against the main valve seat 8a and the sub-valve body 30 is seated on and pressed against the sub-valve seat 8B, and the valve is closed at the same time (fully closed), the compression coil spring 33 is pressed down by the upper flange-shaped portion 20C and a gap La is formed between the lower surface of the upper flange-shaped portion 20C and the upper end of the cylindrical portion 30A of the sub-valve body 30, and a gap Lb is formed between the upper surface of the upper flange-shaped portion 20C and the lower surface of the inner flange-shaped hooking portion 32B of the cylindrical retaining member 32.

On the other hand, as shown in fig. 3, when the stepping motor 50 (the rotor 57) is rotated in one direction and the main valve body 20 moves downward with the sub valve body 30 at the time of the first flow from the lateral direction downward, that is, during the valve closing operation period (1) in which both the main valve body 20 and the sub valve body 30 are in the open state, the sub valve body 30 is pressed downward by the biasing force of the compression coil spring 33, the (lower surface of the) inner flange-shaped hooking portion 32B of the cylindrical retaining member 32 abuts against and is locked to the (upper surface of the) upper flange-shaped portion 20C, and a gap La + Lb is left between the lower surface of the upper flange-shaped portion 20C and the upper end of the cylindrical portion 30A of the sub valve body 30.

During this valve closing operation (1), in this example, the lower end of the sub-valve body 30 is located below the lower end of the main valve body 20, and the refrigerant and foreign matter (metal powder, cutting slag, abrasive, slurry, etc.) contained therein flow between the sub-valve body 30 and the sub-valve seat 8b and between the main valve body 20 and the main valve seat 8 a.

Next, during the valve closing operation period (2) from the state in which the main valve element 20 is opened small and the sub-valve element 30 is slightly opened as shown in fig. 3 to the state in which the main valve element 20 moves further downward as shown in fig. 4 and the sub-valve element 30 is seated on the sub-valve seat 8b and closes, that is, when the gap formed between the sub-valve element 30 and the sub-valve seat 8b gradually decreases and finally becomes 0, foreign matter contained in the refrigerant is blocked by the small gap formed between the sub-valve element 30 and the sub-valve seat 8b, and accumulates and blocks at a portion indicated by an arrow E1 in fig. 4, that is, on the upstream side (outer peripheral side) of the small gap formed between the sub-valve element 30 and the sub-valve seat 8 b. When the sub-valve body 30 is seated on the sub-valve seat 8b and the valve is closed, foreign matter is blocked by the sub-valve body 30 and does not flow to the downstream side (here, the main valve body 20 and the main valve seat 8a on the inner peripheral side).

In this way, during the valve closing operation period (2) from the slightly opened state to the valve closing state of the sub-valve body 30, the main valve body 20 moves downward from the slightly opened state to the slightly opened state, the flow rate of the refrigerant passing through the main valve body 20 gradually decreases, and when the sub-valve body 30 closes, the refrigerant does not flow and the flow rate becomes substantially 0.

Then, when main valve element 20 moves further downward from the slightly opened state shown in fig. 4, as shown in fig. 5, sealing surface 20a of main valve element 20 seats on main valve seat 8a and closes. In this case, main valve element 20 is strongly pressed against main valve seat 8a by the high axial force of the singular planetary gear type speed reduction mechanism 40. At this time, as described above, the compression coil spring 33 is pushed down by the upper flange-like portion 20C by the amount of the gap Lb, the gap formed between the lower surface of the upper flange-like portion 20C and the upper end of the cylindrical portion 30A of the sub-valve body 30 changes from La + Lb to La, and the gap Lb is left between the upper surface of the upper flange-like portion 20C and the lower surface of the inner flange-like hooking portion 32B of the cylindrical stopper member 32, and the sub-valve body 30 is pressed against the sub-valve seat 8B by the biasing force of the compression coil spring 33.

Here, when the sub-valve body 30 is seated on the sub-valve seat 8b and the valve is closed (the state shown in fig. 4), if a foreign object bites into between the sub-valve body 30 and the sub-valve seat 8b, the foreign object is pressed against the sub-valve body 30 and the sub-valve seat 8b by the urging force of the compression coil spring 33 by the amount of the compression Lb, but the pressing force is not so strong, and therefore, scratches, or the like do not occur in the sub-valve body 30 and the sub-valve seat 8 b.

At this time, even if the main valve element 20 is closed from the slightly opened state, foreign matter is blocked by the sub-valve element 30 and the refrigerant does not actually flow, and therefore, the foreign matter does not bite between the main valve element 20 and the main valve seat 8a, and therefore, even if the main valve element 20 is strongly pressed against the main valve seat 8a by the high axial force of the reduction gear mechanism 40 of the planetary gear type, the main valve element 20 and the main valve seat 8a are not scratched or scratched.

When the valve is opened from the fully closed state shown in fig. 5, main valve element 20 is pulled up as shown in fig. 6 by rotating stepping motor 50 (rotor 57) in the other direction. In this case, when the main valve element 20 is pulled up by the amount of the gap Lb, the main valve element 20 slightly opens from the valve-closed state, and thereby the upper surface of the upper flange-like portion 20C abuts against and is locked to the lower surface of the inner flange-like hooking portion 32B of the cylindrical retaining member 32 by the biasing force of the compression coil spring 33, and the gap formed between the lower surface of the upper flange-like portion 20C and the upper end of the cylindrical portion 30A of the sub valve element 30 changes from La to La + Lb, and the sub valve element 30 maintains the valve-closed state, but the pressing force of the compression coil spring 33 decreases.

When the main valve element 20 is further pulled up from this state, the seal surface 30a of the sub valve element 30 is separated from the sub valve seat 8b, and the main valve element 20 is opened small and the sub valve element 30 is slightly opened as shown in fig. 3.

As described above, although the description has been given of the case of the first flow downward from the lateral direction, in the case of the second flow downward from the lateral direction, similarly, as shown in fig. 7 and 8 (the state corresponding to fig. 3 and 4), when the main valve body 20 is moved downward from the state in which the main valve body 20 is small-opened and the sub valve body 30 is slightly-opened, and the clearance formed between the sub valve body 30 and the sub valve seat 8b gradually decreases to eventually become 0, the foreign matter contained in the refrigerant is caught by the minute clearance formed between the sub valve body 30 and the sub valve seat 8b, and tends to accumulate and clog at a portion indicated by an arrow E2 in fig. 8, that is, at a downstream side (outer peripheral side) of the clearance formed between the main valve body 20 and the main valve seat 8a, and at an upstream side (inner peripheral side) of the minute clearance formed between the sub valve body 30 and the sub valve seat 8 b.

During a valve closing operation period (2) from the slightly opened state to the valve closing state of the sub-valve body 30, the main valve body 20 moves downward from the slightly opened state to the slightly opened state, the flow rate of the refrigerant passing through the main valve body 20 gradually decreases, and when the sub-valve body 30 closes, the refrigerant does not flow, so that foreign matter does not block the gap between the main valve body 20 and the main valve seat 8 a.

Then, when main spool 20 moves further downward from the slightly open state shown in fig. 8, main spool 20 seats on main valve seat 8a to close the valve. At this time, as described above, the compression coil spring 33 is pushed down by the upper flange-like portion 20C by the gap Lb, the gap formed between the lower surface of the upper flange-like portion 20C and the upper end of the cylindrical portion 30A of the sub-valve body 30 changes from La + Lb to La, the gap Lb is left between the upper surface of the upper flange-like portion 20C and the lower surface of the inner flange-like hooking portion 32B of the cylindrical stopper member 32, and the sub-valve body 30 is pressed against the sub-valve seat 8B by the biasing force of the compression coil spring 33.

Here, in the case where a foreign object is caught between the sub-valve body 30 and the sub-valve seat 8b when the sub-valve body 30 is seated on the sub-valve seat 8b and the valve is closed (the state shown in fig. 8) in the same manner in the second flow, the foreign object is pressed against the sub-valve body 30 and the sub-valve seat 8b by the compression coil spring 33 compressed by Lb, but the pressing force is not so strong, and therefore, scratches, and the like do not occur in the sub-valve body 30 and the sub-valve seat 8 b.

At this time, even if main valve element 20 is closed from a slightly opened state, the refrigerant does not actually flow, and therefore, a foreign object hardly bites between main valve element 20 and main valve seat 8a, and therefore, even if main valve element 20 is strongly pressed against main valve seat 8a, scratches, and the like do not occur in main valve element 20 and main valve seat 8 a.

As described above, in the motor-operated valve 1 of the present embodiment, since the sub-valve body 30 that closes the valve port 9 prior to the main valve body 20 is provided on the outer periphery of the main valve body 20, when the sub-valve body 30 is in a slightly opened state, foreign matter contained in the fluid (refrigerant) is blocked by the sub-valve body 30, and when the sub-valve body 30 closes from there, the fluid (refrigerant) does not actually flow, and therefore the foreign matter is not caught between the main valve body 20 and the main valve seat 8a, and therefore, even if the main valve body 20 closes and is strongly pressed against the main valve seat 8a, scratches, and the like do not occur in the main valve body 20 and the main valve seat 8 a.

Further, although there is a possibility that foreign matter may bite into between the sub-valve body 30 and the sub-valve seat 8b, the sub-valve body 30 is biased only by the compression coil spring 33, and therefore the pressing force thereof is not so strong, and therefore, scratches, or the like do not occur in the sub-valve body 30 and the sub-valve seat 8 b.

Even if foreign matter bites into the gap between the sub-valve body 30 and the sub-valve seat 8b to generate a gap therebetween, the main valve body 20 closes, and therefore valve leakage does not occur.

As described above, in the gear-reduction-type motor-operated valve 1 according to the first embodiment, in order to improve the sealing property and reliably prevent the valve leakage, the singular planetary gear type reduction mechanism 40 is interposed between the rotor 57 and the screw feed mechanism (the bearing member 15 provided with the female screw 15i, and the rotary vertical movement shaft 17 provided with the male screw 17 e) to increase the axial force of the main valve body 20, that is, the pressing force of the main valve body 20 against the main valve seat 8a, and in such a configuration, it is possible to make difficult the occurrence of a situation in which foreign matter contained in the fluid (refrigerant) is caught between the main valve body 20 and the main valve seat 8a and is strongly pressed against the main valve body 20 and the main valve seat 8a, and therefore, scratches, or the like do not occur in the main valve seat 8a, the sub valve seat 8b, the main valve body 20, and the sub valve body 30. As a result, valve leakage can be effectively prevented and reliability of the closed valve can be improved.

[ second embodiment ]

Fig. 9 is an overall vertical cross-sectional view illustrating a fully closed state of the electrically operated valve according to the second embodiment of the present invention. Fig. 10 to 13 are enlarged vertical sectional views of essential parts for explaining the structure and operation of the motor-operated valve shown in fig. 9.

The motor-operated valve 2 of the second embodiment shown in the figure has substantially the same configuration as the motor-operated valve 1 of the first embodiment shown in fig. 1 to 8 except for the periphery of the main valve body and the sub valve body. Therefore, portions corresponding to the respective portions of the motor-operated valve 1 of the first embodiment and portions having the same functions are denoted by common reference numerals, and overlapping description is omitted, and the following description will be made centering around the main valve body and the sub valve body.

In the motor-operated valve 2 of the illustrated embodiment, the tubular base 10B constituting the valve main body 10 includes a lower cylindrical portion 10a having a large diameter with a bottom, an intermediate thick portion 10B, and an upper cylindrical portion 10c inserted into the housing 58. A valve chamber 7 is formed in a lower cylindrical portion 10a of the cylindrical base 10B, a lateral first inlet/outlet (conduit fitting) 11 that opens into the valve chamber 7 is attached to a side portion of the lower cylindrical portion 10a, a valve seat portion 8 is integrally provided in a bottom portion of the lower cylindrical portion 10a, the valve seat portion 8 is formed with a vertical valve port 9 that opens into the valve chamber 7 from below, a main valve seat 8a formed by an upper end inner peripheral corner portion of the valve port 9, and a sub valve seat 8B formed by an upper outer peripheral conical surface of the valve port 9 (see fig. 10 to 13), and a second inlet/outlet (conduit fitting) 12 that connects to the valve port 9 is attached to the valve seat portion 8.

An annular base 13 is attached to an outer peripheral step portion of the intermediate thick portion 10B of the tubular base 10B, and a lower end portion of a cylindrical case 58 with a top portion is hermetically joined to an upper end outer peripheral portion of the annular base 13 by welding or the like. A base portion of the upper cylindrical portion 10c of the tubular base 10B is fixed to the inner peripheral side of the annular base 13 by press fitting or the like, a bearing member 15 is fixed to the upper cylindrical portion 10c of the tubular base 10B by caulking, and a female screw 15i is provided on the lower inner periphery of the bearing member 15.

An upper end flange portion 65D of a stepped cylindrical body 65 made of sheet metal serving as both a spring receiving portion and a main valve guide portion is sandwiched between the lower surface of the bearing member 15 and the inner peripheral step portion of the intermediate thick portion 10B of the cylindrical base 10B. The stepped cylinder 65 has a lower small-diameter guide portion 65A and an upper large-diameter portion 65B, an annular step (step) portion 65C is interposed between the lower small-diameter guide portion 65A and the upper large-diameter portion 65B, the main valve 70 (the body portion 70B thereof) is slidably fitted into the lower small-diameter guide portion 65A, the upper large-diameter portion 65B is provided with the upper end flange portion 65D, and the valve-opening spring 25 formed of a compression coil spring is compression-mounted between the step portion 65C and the large-diameter upper portion 23a of the thrust transmission member 23.

The main valve element 70 is a poppet valve that moves vertically with respect to the main valve seat 8a to open and close the valve port 9. Main spool 70 has: a main valve body portion 70A having a large diameter, the main valve body portion 70A being in contact with and separated from the main valve seat 8a of the seat portion 8 to open and close the valve port 9; a small-diameter body portion 70B, the body portion 70B being located above the main valve element portion 70A; and an upper projection 70C fixedly attached to the small-diameter lower portion 23C of the thrust transmission member 23 by press fitting or the like, and the body portion 70B is slidably fitted into the lower small-diameter guide portion 65A of the stepped cylindrical body 65. An inverted conical sealing surface 70A (see fig. 10 to 13) that comes into substantially line contact with the main valve seat 8a is provided on the outer peripheral portion of the lower surface of the main valve body 70A so as to obtain a desired sealing property.

In the present embodiment, a sub-valve body 80 for opening and closing the valve port 9 is disposed on the lower outer peripheral side of the main valve body 70 so as to be slidable in the vertical direction. That is, as described above, the main valve seat 8a that is in contact with and separated from the sealing surface 70A of the main valve body 70A is provided on the upper inner peripheral side (corner) of the seat portion 8 (the valve port 9) of the valve main body 10, the sub valve seat 8b having a truncated conical shape is provided on the upper outer peripheral side of the seat portion 8 and separated from the main valve seat 8a, and the sub valve seat 8b is in contact with and separated from the sealing surface (the lower end inner peripheral side corner) 80A of the sub valve body 80.

The sub-valve body 80 is formed in a stepped cylindrical shape and is composed of: a large diameter outer insertion part 80A slidably inserted in the outer periphery of a main valve part 70A of the main valve 70; a small-diameter external insertion portion 80B slidably inserted into the body portion 70B of the main valve body 70; and an annular step (step) portion 80C serving as both a disengagement prevention portion and a spring receiving portion (specifically, a lower surface is defined as the disengagement prevention portion and an upper surface is defined as the spring receiving portion) between the large-diameter outer insertion portion 80A and the small-diameter outer insertion portion 80B. A compression coil spring 73 is mounted in compression between the step portion 80C and the step portion 65C of the stepped cylindrical body 65 as a stationary portion provided on the upper side of the step portion 80C of the valve body 10, and the compression coil spring 73 serves as an urging member that constantly urges the sub-valve 80 downward (in the valve closing direction). Here, (the sealing surface (lower end inner peripheral side corner) 80A) of the large diameter outer insertion portion 80A is configured to move vertically in the vertical direction with respect to the sub-valve seat 8b to open and close the valve port 9.

Further, a seal member such as an O-ring may be interposed between the small-diameter outer insert portion 80B of the sub-valve body 84 and the sliding surface of the body portion 70B of the main valve body 70.

Next, the opening and closing operation including the sub valve body 80 in the motor-operated valve 2 having the above-described configuration will be described with reference to fig. 10 to 13.

First, as shown in fig. 12, in a state where the valve closing operation is completed, that is, when the main valve body 70 is seated on and pressed against the main valve seat 8a and the sub valve body 80 is seated on and pressed against the sub valve seat 8b, a gap Lc is left between the upper surface of the main valve body portion 70A and the lower surface of the step portion 80C of the sub valve body 80 when the valve is closed at the same time (when the valve is fully closed).

On the other hand, as shown in fig. 10, at the time of the first flow from the lateral direction downward, the stepping motor 50 (rotor 57) is rotated in one direction, and during the valve closing operation period (1) in which the main valve element 70 moves downward along with the sub valve element 80, the sub valve element 80 is pressed downward by the urging force of the compression coil spring 73, and the step portion 80C of the sub valve element 80 abuts against and is locked to the upper surface of the main valve element portion 70A, and in this example, the lower end of the sub valve element 80 is located lower than the lower end of the main valve element 70, and the refrigerant and foreign substances (metal powder, cutting slag, abrasive, slurry, and the like) contained therein flow between the sub valve element 80 and the sub valve seat 8b and between the main valve element 70 and the main valve seat 8 a.

Next, from the state where the main valve element 70 is small-opened and the sub-valve element 80 is slightly opened as shown in fig. 10, as shown in fig. 11, the main valve element 70 is further moved downward until the period (2) of the valve closing operation where the sub-valve element 80 is seated on the sub-valve seat 8b and closed, that is, when the gap formed between the sub-valve element 80 and the sub-valve seat 8b gradually becomes smaller and finally becomes 0, foreign matter contained in the refrigerant is caught by the small gap formed between the sub-valve element 80 and the sub-valve seat 8b, and tends to accumulate and clog at a portion indicated by an arrow E1 in fig. 11, that is, at the upstream side (outer peripheral side) of the small gap formed between the sub-valve element 80 and the sub-valve seat 8 b. When the sub-valve body 80 is seated on the sub-valve seat 8b and the valve is closed, foreign matter is blocked by the sub-valve body 80 and does not flow to the downstream side (here, the main valve body 70 and the main valve seat 8a on the inner peripheral side).

In this way, during the valve closing operation period (2) from the slightly opened state to the valve closing state of the sub-valve 80, the main valve element 70 moves downward from the slightly opened state to the slightly opened state, the flow rate of the refrigerant passing through the main valve element 70 gradually decreases, and when the sub-valve element 80 closes, the refrigerant does not flow and the flow rate becomes substantially 0.

Next, when the main valve body 70 moves further downward from the slightly opened state shown in fig. 11, as shown in fig. 12, the sub valve body 80 is pressed against the sub valve seat 8b by the biasing force of the compression coil spring 73, and the main valve body 70 is seated on the main valve seat 8a and strongly pressed against the main valve seat 8a by the high axial force of the reduction gear mechanism 40 of the planetary gear type, thereby becoming the fully closed state. At the time of this full closing, as described above, a gap Lc is left between the upper surface of the main valve body portion 70A and the lower surface of the stepped portion 80C of the sub valve body 80.

Here, when the sub-valve 80 is seated on the sub-valve seat 8b and the valve is closed (the state shown in fig. 11), if foreign matter is caught between the sub-valve 80 and the sub-valve seat 8b, the foreign matter is pressed against the sub-valve 80 and the sub-valve seat 8b by the urging force of the compression coil spring 73, but the pressing force is not so strong, and therefore, scratches, or the like do not occur in the sub-valve 80 and the sub-valve seat 8 b.

At this time, even if the main valve element 70 is closed from the slightly opened state, foreign matter is blocked by the sub valve element 80 and the refrigerant does not substantially flow, and therefore, the foreign matter is not caught between the main valve element 70 and the main valve seat 8a, and therefore, even if the main valve element 70 is strongly pressed against the main valve seat 8a by the high axial force of the reduction gear mechanism 40 of the planetary gear type, the main valve element 70 and the main valve seat 8a are not scratched or scratched.

When the valve is opened from the fully closed state shown in fig. 12, the stepping motor 50 (rotor 57) is rotated in the other direction, and thereby the main valve element 70 is pulled up and opened as shown in fig. 13. In this case, when the main valve element 70 is pulled up by the clearance Lc, the upper surface of the main valve element portion 70A abuts against the lower surface of the step portion 80C of the sub valve element 80, and when the main valve element 70 is further pulled up, the sub valve element 80 is pulled up accordingly, the sealing surface 80A of the sub valve element 80 is separated from the sub valve seat 8b, and the sub valve element 80 is also opened.

The above description has been made on the first flow from the lateral direction, but the same operation as that in the first flow is performed also in the second flow from the downward direction to the lateral direction, and the same operational effects as those in the second flow of the first embodiment described with reference to fig. 7 and 8 can be obtained.

As described above, in the motor-operated valve 2 according to the second embodiment, since the sub-valve 80 that closes the valve port 9 prior to the main valve 70 is provided on the outer periphery of the main valve 70, when the sub-valve 80 is in the slightly opened state, foreign matter contained in the fluid (refrigerant) is blocked by the sub-valve 80, and when the sub-valve 80 is closed from there, the fluid (refrigerant) does not actually flow, and therefore the foreign matter is not caught between the main valve 70 and the main valve seat 8a, and therefore, even if the main valve 70 is closed and strongly pressed against the main valve seat 8a, scratches, and the like do not occur in the main valve 70 and the main valve seat 8 a.

Further, although there is a possibility that foreign matter may bite into between the sub-valve 80 and the sub-valve seat 8b, the sub-valve 80 is biased only by the compression coil spring 73, and therefore the pressing force is not so strong, and therefore, scratches, or the like do not occur in the sub-valve 80 and the sub-valve seat 8 b.

Even if foreign matter bites into the gap between the sub-valve body 80 and the sub-valve seat 8b to generate a gap therebetween, the main valve body 70 closes, and therefore valve leakage does not occur.

As described above, in the gear-reduction-type motor-operated valve 2 according to the second embodiment, it is possible to prevent foreign matter contained in the fluid (refrigerant) from being caught between the main valve body 70 and the main valve seat 8a and being strongly pressed against the main valve body 70 and the main valve seat 8a, and therefore, scratches, and the like do not occur in the main valve seat 8a, the sub-valve seat 8b, the main valve body 70, and the sub-valve body 80. As a result, valve leakage can be effectively prevented and reliability of the closed valve can be improved.

[ third embodiment ]

Fig. 14 to 17 are enlarged vertical sectional views of essential parts for explaining the structure and operation of the motor-operated valve according to the third embodiment of the present invention.

The motor-operated valve 3 according to the third embodiment shown in the figure has substantially the same configuration as the motor-operated valve 2 according to the second embodiment shown in fig. 9 to 13, except for the periphery of the main valve body and the sub valve body. Therefore, portions corresponding to the respective portions of the motor-operated valve 2 according to the second embodiment and portions having the same functions are denoted by common reference numerals, and overlapping description is omitted, and the following description will be made centering around the main valve body and the sub valve body.

In the motor-operated valve 3 of the illustrated embodiment, in contrast to the motor-operated valve 2 of the second embodiment described above, a main valve seat 8a is provided on the outer peripheral side (corner) of the seat portion 8, and a sub-valve seat 8b is provided on the inner peripheral side (corner) of the seat portion 8. The main valve body 72 is formed in a cylindrical shape, the sub-valve body 82 is formed in an inverted truncated cone shape, and (the inverted truncated cone-shaped sealing surface 72A of the main valve body portion 72A of) the main valve body 72 is positioned on the outer peripheral side of (the inverted truncated cone-shaped sealing surface 82A of) the sub-valve body 82 (in other words, the sub-valve body 82 is positioned inside the main valve body 72).

Specifically, the main spool 72 includes: a cylindrical body portion 72B; a flange-shaped main valve element 72A, the main valve element 72A projecting outward from the lower end of the cylindrical body 72B and having an inverted truncated cone-shaped sealing surface 72A; and an upper end inner flange portion 72C provided to protrude inward from the upper end of the cylindrical body portion 72B, and fixedly attached to the lower end portion of the body portion 70B in the second embodiment by press fitting or the like.

An upper end portion of a sub-valve body support rod 75 is fixedly attached to a lower center of the body portion 70B by press fitting or the like, and a sub-valve body 82 is slidably inserted into the sub-valve body support rod 75. A large-diameter disengagement prevention portion 75a is provided at the lower end of the sub-valve support lever 75, and the large-diameter disengagement prevention portion 75a is fitted into a lower end recess 83 provided at the top end surface (lower end surface) of the sub-valve 82 to disengage and engage the sub-valve 82. Here, the tip end surface (lower end surface) of the sub-valve body 82 is an inverted truncated cone shaped sealing surface 82a, and the sealing surface 82a moves vertically in the vertical direction with respect to the sub-valve seat 8b inside the main valve seat 8a to open and close the valve port 9.

A compression coil spring 77 that constantly biases the sub-valve body 82 downward (in the valve closing direction) is mounted in compression between the inner flange-shaped portion 72C at the upper end of the main valve body 72 and the sub-valve body 82.

Next, the opening and closing operation including the sub valve body 82 in the motor-operated valve 3 having the above-described configuration will be described with reference to fig. 14 to 17.

First, as shown in fig. 16, in a state where the valve closing operation is completed, that is, the main valve body 72 is seated on and pressed against the main valve seat 8a, and the sub-valve body 82 is seated on and pressed against the sub-valve seat 8b, when the valve is closed at the same time (when fully closed), a gap Ld is left between the upper surface of the lower end recess 83 of the sub-valve body 82 and the upper surface of the disengagement prevention locking portion 75a of the sub-valve body support rod 75.

On the other hand, as shown in fig. 14, at the time of the first flow from the lateral direction downward, the stepping motor 50 (the rotor 57) is rotated in one direction, and during the valve closing operation period (1) in which the main valve element 72 moves downward along with the sub valve element 82, the sub valve element 82 is pressed downward by the biasing force of the compression coil spring 77, and the sub valve element 82 abuts against and is locked to the disengagement prevention locking portion 75a of the sub valve element support rod 75, and in this example, the lower end of the sub valve element 82 is located below the lower end of the main valve element 72, and the refrigerant and foreign substances (metal powder, cutting slag, abrasive, slurry, and the like) contained therein flow between the sub valve element 82 and the sub valve seat 8b and between the main valve element 72 and the main valve seat 8 a.

Next, from the state where the main valve element 72 is small-opened and the sub-valve element 82 is slightly opened as shown in fig. 14, as shown in fig. 15, the main valve element 72 is further moved downward until the valve closing operation period (2) where the sub-valve element 82 is seated on the sub-valve seat 8b and closes, that is, when the gap formed between the sub-valve element 82 and the sub-valve seat 8b gradually decreases and finally becomes 0, foreign matter contained in the refrigerant is caught by the small gap formed between the sub-valve element 82 and the sub-valve seat 8b, and accumulates on the upstream side (outer circumferential side) of the small gap formed between the sub-valve element 82 and the sub-valve seat 8b, and tends to be clogged. When the sub-valve body 82 is seated on the sub-valve seat 8b and the valve is closed, foreign matter is blocked by the sub-valve body 82 and does not flow to the downstream side (here, the inner peripheral side valve port 9 side).

In this way, during the valve closing operation period (2) from the slightly opened state to the valve closing state of the sub-valve 82, the main valve 72 moves downward from the slightly opened state to the slightly opened state, the flow rate of the refrigerant passing through the main valve 72 gradually decreases, and when the sub-valve 82 closes, the refrigerant does not flow and the flow rate becomes substantially 0.

Next, when the main valve body 72 moves further downward from the slightly opened state shown in fig. 15, as shown in fig. 16, the sub valve body 82 is pressed against the sub valve seat 8b by the biasing force of the compression coil spring 77, and the main valve body 72 is seated on the main valve seat 8a and strongly pressed against the main valve seat 8a by the high axial force of the reduction gear mechanism 40, thereby becoming a fully closed state. At the time of this full closing, as described above, a gap Ld is left between the upper surface of the lower end recess 83 of the sub-spool 82 and the upper surface of the disengagement prevention portion 75a of the sub-spool support lever 75.

Here, when the sub-valve body 82 is seated on the sub-valve seat 8b and the valve is closed (the state shown in fig. 15), if foreign matter is caught between the sub-valve body 82 and the sub-valve seat 8b, the foreign matter is pressed against the sub-valve body 82 and the sub-valve seat 8b by the urging force of the compression coil spring 77, but the pressing force is not so strong, and therefore, scratches, or the like do not occur in the sub-valve body 82 and the sub-valve seat 8 b.

At this time, even if the main valve element 72 is closed from the slightly opened state, since foreign matter is blocked by the sub-valve element 82 and the refrigerant does not substantially flow, there is almost no possibility of the foreign matter biting into between the main valve element 72 and the main valve seat 8a, and therefore, even if the main valve element 72 is strongly pressed against the main valve seat 8a by the high axial force of the reduction gear mechanism 40 of the planetary gear type, no scratch, damage, or the like is generated in the main valve element 72 and the main valve seat 8a (refer to the description of the operation in the second flow using the first embodiment described with reference to fig. 7 and 8).

When the valve is opened from the fully closed state shown in fig. 16, the stepping motor 50 (rotor 57) is rotated in the other direction, and thereby the main valve 72 is pulled up and opened as shown in fig. 17. In this case, when the main valve element 72 is pulled up by the clearance Ld, the upper surface of the disengagement prevention portion 75a of the sub-valve element support rod 75 abuts against the upper surface of the lower end concave portion 83 of the sub-valve element 82, and when the main valve element 72 is further pulled up, the sub-valve element 82 is pulled up accordingly, the sealing surface 82a of the sub-valve element 82 is separated from the sub-valve seat 8b, and the sub-valve element 82 is also opened.

The above description has been made on the first flow from the lateral direction downward, and the same operation as that in the first flow is performed also in the second flow from the downward direction to the lateral direction, and the same operational effects as those in the second flow of the first embodiment described with reference to fig. 7 and 8 and in the first flow of the second embodiment described with reference to fig. 9 to 13 can be obtained.

In the example shown in fig. 14 to 17, the main valve seat 8a is provided at the outer peripheral corner of the seat portion 8, and the sub-valve seat 8b is provided at the inner peripheral corner of the seat portion 8, but for example, as shown in fig. 18, the upper surface of the seat portion 8 may be an inclined surface, the main valve seat 8a may be provided on the inclined surface, and the sub-valve seat 8b may be provided at the inner end (corner) of the inclined surface. In this case, the lower end portion of the cylindrical body portion 72B of the main valve body 72 may be the main valve body portion 72A having the seal surface 72A.

As described above, in the motor-operated valve 3 according to the third embodiment as well, like the motor-operated valves 1 and 2 according to the first and second embodiments, since the sub-valve 82 that closes the valve port 9 prior to the main valve 72 is provided on the outer periphery of the main valve 72, when the sub-valve 82 is in the slightly opened state, foreign matter contained in the fluid (refrigerant) is caught by the sub-valve 82, and when the sub-valve 82 closes from there, the fluid (refrigerant) does not substantially flow, and therefore the foreign matter is not caught between the main valve 72 and the main valve seat 8a, and therefore, even if the main valve 72 closes and is strongly pressed against the main valve seat 8a, scratches, and the like are not generated in the main valve 72 and the main valve seat 8 a.

Further, although there is a possibility that foreign matter may bite into between the sub-valve body 82 and the sub-valve seat 8b, the sub-valve body 82 is biased only by the compression coil spring 73, and therefore the pressing force thereof is not so strong, and therefore, scratches, or the like do not occur in the sub-valve body 82 and the sub-valve seat 8 b.

Even if foreign matter bites into the gap between the sub-valve body 82 and the sub-valve seat 8b to generate a gap therebetween, the main valve body 72 closes, and therefore valve leakage does not occur.

As described above, in the gear-reduction-type motor-operated valve 3 according to the third embodiment, it is possible to prevent foreign matter contained in the fluid (refrigerant) from being caught between the main valve element 72 and the main valve seat 8a and being strongly pressed against the main valve element 72 and the main valve seat 8a, and therefore, scratches, and the like do not occur in the main valve seat 8a, the sub-valve seat 8b, the main valve element 72, and the sub-valve element 82. As a result, valve leakage can be effectively prevented and reliability of the closed valve can be improved.

[ fourth embodiment ]

Fig. 19 is an overall vertical cross-sectional view illustrating a fully closed state of the fourth embodiment of the motor-operated valve of the present invention. Fig. 20 to 23 are enlarged vertical sectional views of essential parts for explaining the structure and operation of the motor-operated valve shown in fig. 19.

The motor-operated valve 4 of the fourth embodiment is a direct-drive type structure, and is mainly configured by removing the singular planetary gear type reduction mechanism 40 and the related parts thereof from the motor-operated valve 2 of the second embodiment shown in fig. 9 to 13, and the main valve body, the sub valve body, and the like have a shape similar to the structure of the second embodiment. Therefore, portions corresponding to the respective portions of the motor-operated valve 2 according to the second embodiment and portions having the same functions are denoted by common reference numerals, and redundant description is omitted, and differences will be mainly described below. That is, first, a basic overall structure excluding the sub-valve body will be described, and then, the characteristic portions of the present invention including the sub-valve body will be described. In addition, for a detailed configuration and operation of the motor-operated valve 4 according to the fourth embodiment, refer to the above-mentioned patent document 1 and the like, if necessary.

The motor-operated valve 4 of the illustrated embodiment basically has: a valve shaft 125, the valve shaft 125 integrally provided with the main spool 74; a valve main body 10, the valve main body 10 having a bottomed tubular base body 10B provided with a valve chamber 7, a valve port 9, a valve seat portion 8, and the like; a cylindrical case 58 with a top, a lower end portion of the case 58 being hermetically joined to the valve main body 10 by welding or the like; a stepping motor 50, the stepping motor 50 including a rotor 57 and a stator 55, the rotor 57 being disposed with a predetermined gap in an inner periphery of the housing 58, the stator 55 being externally fitted to the housing 58 to drive the rotor 57 to rotate; and a screw feed mechanism which is disposed between the rotor 57 and the main valve body 74, and which brings the main valve body 74 into contact with and away from a main valve seat 8a formed in the seat portion 8 by rotation of the rotor 57.

A support ring 136 is integrally joined to the rotor 57, and an upper projection of a cylindrical valve shaft holder 132 having a lower opening is fixed by caulking to the support ring 136, and the valve shaft holder 132 is disposed on the outer periphery of the valve shaft 125 and the guide bush 126, whereby the rotor 57, the support ring 136, and the valve shaft holder 132 are integrally coupled.

The screw feeding mechanism includes a fixed screw portion (male screw portion) 128 formed on the outer periphery of a cylindrical guide bush 126, a lower end portion 126a of the guide bush 126 press-fitted and fixed to a fitting hole 142 provided in a cylindrical base body 10B of the valve body 10, a (lower large diameter portion 125a of the) valve shaft 125 slidably inserted into the guide bush 126, and a moving screw portion (female screw portion) 138 formed on the inner periphery of the valve shaft holder 132 and screwed into the fixed screw portion 128.

The upper small diameter portion 126b of the guide bush 126 is inserted into the upper portion of the valve shaft holder 132, and the upper small diameter portion 125b of the valve shaft 125 is inserted through the center (formed through hole) of the top of the valve shaft holder 132. A locknut (pushnut)133 is press-fitted and fixed to an upper end portion (a portion protruding upward from the through hole of the valve shaft holder 132) of the upper small diameter portion 125b of the valve shaft 125.

The valve shaft 125 is constantly biased downward (in the valve closing direction) by a valve closing spring 134 formed of a compression coil spring, and the valve closing spring 134 is inserted around the upper small diameter portion 125b of the valve shaft 125 and is compression-fitted between the top of the valve shaft holder 132 and the upper stepped surface of the lower large diameter portion 125a of the valve shaft 125. A return spring 135 made of a coil spring is provided on the top of the valve shaft holder 132 and on the outer periphery of the locknut 133.

A lower stopper (fixed stopper) 127 constituting a rotation/lowering stopper mechanism for preventing the rotor 57 from further rotating and lowering when the rotor 57 rotates and lowers to a predetermined valve closing position is fixedly attached to the guide bush 126, and an upper stopper (moving stopper) 137 constituting the rotation/lowering stopper mechanism is fixed to the outside of the valve shaft holder 132.

In the direct-acting motor-operated valve 4 configured as described above, similarly, when the stepping motor 50 (the rotor 57) is rotated in one direction, the valve shaft 125 is moved downward, for example, while being rotated by screw transmission including the fixed screw portion (the male screw portion) 128 and the moving screw portion (the female screw portion) 138 screwed thereto, and finally the seal surface 74a of the main valve 74 is pressed against the main valve seat 8a (see fig. 20 to 23), and the valve port 9 is closed.

On the other hand, when the stepping motor 50 (the rotor 57) is rotated in the other direction, the valve shaft 125 moves upward while rotating by the screw transmission constituted by the fixed screw portion (the male screw portion) 128 and the moving screw portion (the female screw portion) 138 screwed thereto, and the sealing surface 74a of the main valve 74 is separated from the main valve seat 8a accordingly (see fig. 20 to 23) to open the valve port 9.

Next, the structure around the main valve body 74 and the sub valve body 84 of the motor-operated valve 4 will be described with reference to fig. 20 to 23.

In the motor-operated valve 4 of the present embodiment, the main valve 74 includes: a large diameter portion 74C for locking, the large diameter portion 74C being provided continuously with a lower portion of the valve shaft 125 and being slightly larger than the diameter of the valve shaft 125; a main spool portion 74A, the main spool portion 74A having a seal surface 74A constituted by an inverted conical table surface; and a tapered lower portion 74B having an inverted truncated cone shape, the tapered lower portion 74B being provided continuously with the lower side of the main valve element portion 74A and inserted through the valve port 9. A sub-valve body 84 for opening and closing the valve port 9 is disposed slidably in the vertical direction at the lower portion of the valve shaft 125 and on the outer peripheral side of the main valve body 74.

The sub-valve body 84 is formed in a stepped cylindrical shape and has the following structure: a large-diameter valve body portion (large-diameter outer insertion portion) 84A disposed on the outer peripheral side of the main valve 74 (with an open gap); a small-diameter external insertion portion 84B slidably inserted in a lower portion of the valve shaft 125; and an annular step (step) portion 84C serving as both a disengagement prevention portion and a spring receiving portion (specifically, a lower surface is the disengagement prevention portion and an upper surface is the spring receiving portion) between the large-diameter spool portion 84A and the small-diameter outer insertion portion 84B. That is, the stepped portion 84C is locked to the locking large diameter portion 74C of the main valve 74. Here, (the sealing surface (lower end flat surface) 84A of) the large diameter valve body portion 84A is provided to move vertically in the vertical direction with respect to the sub-valve seat 8b to open and close the valve port 9, and the sub-valve seat 8b is formed of a flat surface formed on the upper surface of the valve seat portion 8.

A compression coil spring 73 as an urging member is compressively attached between the step portion 84C of the sub-valve body 84 and a lower end portion 126a of a guide bush 126 as a stationary portion provided above the step portion 80C of the valve body 10, and the compression coil spring 73 constantly urges the sub-valve body 84 downward (in the valve closing direction).

Further, a seal member such as an O-ring may be interposed between the small-diameter outer insert portion 84B of the sub-valve body 84 and a lower sliding surface of the valve shaft 125.

As shown in fig. 22, in addition to the above-described configuration, in a state where the valve closing operation is completed, that is, the main valve body 74 is seated on and pressed by the main valve seat 8a, and the sub valve body 84 is seated on and pressed by the sub valve seat 8b, when the valve is closed (fully closed), a gap Le is left between an upper surface of the large diameter portion 74C for locking and a lower surface of the step portion 84C.

As is apparent from fig. 20 to 23, in the motor-operated valve 4 of the fourth embodiment having such a configuration, as in the motor-operated valve 2 of the second embodiment, since the sub-valve 84 that closes the valve port 9 prior to the main valve 74 is provided on the outer periphery of the main valve 74, when the sub-valve 84 is in a slightly opened state, foreign matter contained in the fluid (refrigerant) is blocked by the sub-valve 84, and when the sub-valve 84 is closed from there, the fluid (refrigerant) does not substantially flow, and therefore foreign matter is not caught between the main valve 74 and the main valve seat 8a, and therefore, even if the main valve 74 is closed and strongly pressed against the main valve seat 8a, scratches, and the like do not occur in the main valve 74 and the main valve seat 8 a.

Further, although there is a possibility that foreign matter may bite into between the sub-valve body 84 and the sub-valve seat 8b, the sub-valve body 84 is biased only by the compression coil spring 73, and therefore the pressing force thereof is not so strong, and therefore, scratches, or the like do not occur on the sub-valve body 84 and the sub-valve seat 8 b.

Even if foreign matter bites into the gap between the sub-valve body 84 and the sub-valve seat 8b to generate a gap therebetween, the main valve body 74 closes, and therefore valve leakage does not occur.

As described above, in the direct-acting motor-operated valve 4 according to the fourth embodiment, since it is possible to prevent foreign matter contained in the fluid (refrigerant) from being caught between the main valve element 74 and the main valve seat 8a and being strongly pressed against the main valve element 74 and the main valve seat 8a, scratches, and the like are not generated in the main valve seat 8a, the sub-valve seat 8b, the main valve element 74, and the sub-valve element 84. As a result, valve leakage can be effectively prevented and reliability of the closed valve can be improved.

[ fifth embodiment ]

Fig. 24 to 27 are mainly enlarged vertical cross-sectional views for explaining the structure and operation of a fifth embodiment of an electrically operated valve used in the present invention.

The overall configuration of the motor-operated valve 5 of the fifth embodiment is the same as that of the motor-operated valve 4 of the fourth embodiment (see fig. 19), except for the main valve body and the sub valve body, and the main valve body and the sub valve body are configured similarly to the motor-operated valve 3 of the third embodiment shown in fig. 14 to 17. Therefore, portions corresponding to the portions of the motor-operated

valves

3 and 4 according to the third and fourth embodiments and portions having the same functions are denoted by common reference numerals, and overlapping descriptions are omitted, and the main valve body and the sub valve body are briefly described below.

In the motor-operated valve 5 of the illustrated embodiment, in contrast to the motor-operated valve 4 of the fourth embodiment, and having the same configuration as the motor-operated valve 3 of the third embodiment, a main valve seat 8a is provided on the outer peripheral side (corner) of a seat portion 8, and a sub-valve seat 8b is provided on the inner peripheral side (corner) of the seat portion 8. The main valve body 76 is cylindrical, the sub valve body 86 is formed in a stepped reverse truncated cone shape, and (the reverse truncated cone-shaped sealing surface 76A of the main valve body portion 76A of) the main valve body 76 is positioned on the outer peripheral side of (the reverse truncated cone-shaped sealing surface 86A of the sub valve body portion 86A of) the sub valve body 86 (in other words, the sub valve body 86 is positioned inside the main valve body 76).

Specifically, the main spool 76 includes: a cylindrical body portion 76B; a main valve body portion 76A having an inverted truncated cone shaped sealing surface 76A formed by a lower end portion and an inner peripheral protrusion of the cylindrical body portion 76B; and an upper end fixing portion 76C that is fixedly attached to a lower end flange portion 125d formed on the valve shaft 125 by press fitting or the like. Here, the inner circumferential protrusion constituting the main valve body portion 76A serves as a disengagement prevention portion that (the upper flange portion 86C of) the sub valve body 86 is engaged in a disengagement prevention manner, and the sub valve body 86 is slidably inserted into the cylindrical body portion 76B.

The upper portion of the sub-valve 86 is slidably inserted into the inner peripheral side of the main valve 76. That is, the sub-spool 86 includes, in order from the upper side: an upper flange portion 86C which is slidably inserted into the cylindrical body portion 76B of the main valve element 70 and serves as both an anti-slip portion and a spring receiving portion (specifically, the lower surface is the anti-slip portion and the upper surface is the spring receiving portion); a sub valve body portion 86A disposed inside the main valve body portion 76A (with an open gap therebetween), the sub valve body portion 86A having an inverted truncated conical sealing surface 86A formed thereon; and an inverted truncated cone-shaped tapered lower portion 86B, the tapered lower portion 86B being provided continuously with the lower side of the sub valve body portion 86A and being inserted through the valve port 9. A compression coil spring 77 as an urging member is compression-mounted between the lower end flange portion 125d of the valve shaft 125 (the portion connected to the upper end fixing portion 76C of the main valve body 76) and the upper flange portion 86C of the sub-valve body 86, and the compression coil spring 77 always urges the sub-valve body 86 downward (in the valve closing direction).

As shown in fig. 26, in addition to the above-described configuration, in a state where the valve closing operation is completed, that is, the main valve body 76 is seated on and pressed by the main valve seat 8a, and the sub valve body 86 is seated on and pressed by the sub valve seat 8b, when the valve is closed at the same time (when fully closed), a gap Lf is formed between an upper surface of the inner peripheral protrusion (anti-separation locking portion) of the main valve body 76A and a lower surface of the upper flange portion 86C.

As is apparent from fig. 24 to 27, in the motor-operated valve 5 of the fifth embodiment having such a configuration, as in the motor-operated valve 3 of the third embodiment, since the sub-valve 86 that closes the valve port 9 prior to the main valve 76 is provided on the outer periphery of the main valve 76, when the sub-valve 86 is in a slightly opened state, foreign matter contained in the fluid (refrigerant) is caught by the sub-valve 86, and when the sub-valve 86 closes from there, the fluid (refrigerant) does not substantially flow, and therefore foreign matter is not caught between the main valve 76 and the main valve seat 8a, and therefore, even if the main valve 76 closes and is strongly pressed against the main valve seat 8a, scratches, or the like are not generated in the main valve 76 and the main valve seat 8 a.

Further, although there is a possibility that foreign matter may bite into between the sub-valve body 86 and the sub-valve seat 8b, the sub-valve body 86 is biased only by the compression coil spring 77, and therefore the pressing force is not so strong, and therefore, scratches, or the like do not occur in the sub-valve body 86 and the sub-valve seat 8 b.

Even if foreign matter bites into the gap between the sub-valve body 86 and the sub-valve seat 8b to generate a gap therebetween, the main valve body 76 closes, and therefore valve leakage does not occur.

As described above, in the direct-acting motor-operated valve 5 according to the fifth embodiment, since it is possible to prevent foreign matter from being caught between the main valve element 76 and the main valve seat 8a and strongly pressed against the main valve element 76 and the main valve seat 8a, scratches, and the like are not generated in the main valve seat 8a, the sub valve seat 8b, the main valve element 76, and the sub valve element 86. As a result, valve leakage can be effectively prevented and reliability of the closed valve can be improved.

The motor-operated valve according to the present invention is not limited to the configurations of the above-described embodiments, and various modifications can be made to the configurations around the main valve element and the sub valve element, for example.

Description of the symbols

1. 2, 3, 4, 5 electric valves (first to fifth embodiments)

7 valve chamber

8 valve seat part

8a main valve seat

8b auxiliary valve seat

9 valve port

10 valve body

10A, 10B tubular base

11 first inlet and outlet

12 second inlet and outlet

20. 70, 72, 74, 76 Main valve elements (first to fifth embodiments)

30. 80, 82, 84, 86 auxiliary valve body (first to fifth embodiments)

33. 73, 77 compression coil spring

40-singular planetary gear type speed reducing mechanism

50 stepping motor

55 stator

57 rotor

58 casing

Claims

1. An electrically operated valve having: a valve body provided with a valve chamber, a plurality of inlets and outlets, and a valve port; a main valve body disposed in the valve chamber so as to be movable up and down, the main valve body opening and closing the valve port; a cylindrical housing joined to the valve main body; a stepping motor including a rotor and a stator, the rotor being rotatably disposed inside the housing, the stator being disposed outside the housing; and a screw feed mechanism for converting the rotation of the rotor into the up-and-down movement of the main valve element,

a sub valve body for opening and closing the valve port is disposed on the main valve body so as to be movable up and down, and closes the valve port prior to the main valve body when the main valve body closes the valve port.

2. Electrically operated valve according to claim 1,

the valve port in the valve body is separately provided with a main valve seat and a sub valve seat, the main valve element is in contact with and separated from the main valve seat, and the sub valve element is in contact with and separated from the sub valve seat.

3. Electrically operated valve according to claim 2,

the main valve element moves up and down in the vertical direction relative to the main valve seat to open and close the valve port, and the sub valve element moves up and down in the vertical direction relative to the sub valve seat to open and close the valve port.

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

the sub valve body is disposed on the main valve body so as to be slidable in the vertical direction and to be locked in a slip-proof manner.

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

the sub-valve body is disposed on the outer peripheral side of the main valve body so as to be movable up and down.

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

the sub valve body is disposed on an inner peripheral side of the main valve body so as to be movable up and down.

7. Electrically operated valve according to claim 5,

the main valve element is provided with an upper flange part serving as a locking part and a spring receiving part, and a cylindrical sub valve element with a lower flange part is slidably inserted outside the lower side of the upper flange part, and a cylindrical locking member is arranged on the outer peripheral side of the sub valve element, and the cylindrical locking member is provided with an inner flange-shaped hooking part locked with the upper flange part and is fixedly mounted on the lower flange part,

a compression coil spring is mounted in compression between the upper flange portion and the lower flange portion, and biases the sub-valve body in a valve closing direction.

8. Electrically operated valve according to claim 5,

the main spool has: a main valve element portion having a large diameter, the main valve element portion opening and closing the valve port; and a small-diameter body portion located above the main valve element portion,

the sub-valve body has: a large diameter outer insertion portion slidably or interstitially inserted in the main valve body portion; a small-diameter external insertion portion which is slidably externally inserted into the body portion; and a step portion between the large-diameter outer insertion portion and the small-diameter outer insertion portion, the step portion serving as both a lock prevention portion and a spring receiving portion,

a compression coil spring is mounted in compression between the step portion and a stationary portion provided above the step portion in the valve body, and biases the sub-valve body in a valve closing direction.

9. Electrically operated valve according to claim 6,

the main spool has a cylindrical main spool portion,

the sub valve body is slidably disposed on an inner peripheral side of the main valve body portion, and is locked in a locking portion provided in the main valve body,

a compression coil spring is mounted in a compressed manner between the sub valve body and the main valve body, and the compression coil spring urges the sub valve body in a valve closing direction.

10. Electrically operated valve according to claim 9,

the auxiliary valve core is freely inserted into an auxiliary valve core supporting rod in a sliding manner, and the auxiliary valve core supporting rod is provided with the anti-falling clamping part fixedly arranged on the main valve core.

11. Electrically operated valve according to claim 9,

the sub-valve body is slidably inserted into a cylindrical body portion having the main valve body and the anti-slip portion.

12. Electrically operated valve according to one of the claims 1 to 11,

and a planetary gear type speed reducing mechanism is arranged between the rotor and the thread feeding mechanism.