JP6715879B2 - 3-way switching valve - Google Patents

Description

The present invention relates to a three-way switching valve, and more particularly to a three-way switching valve used as a flow path switching device that can switch the flow direction (flow path) of a fluid (refrigerant) in a refrigerating cycle such as an air conditioner and that can be used for flow rate adjustment Regarding

As a three-way switching valve of this kind, a valve body having an inflow/outflow port, an inflow port, and an outflow port, a first valve seat arranged inside the valve body between the inflow/outflow port and the inflow port, and the valve body. A second valve seat disposed inside the valve between the inflow outlet and the outflow outlet, and disposed on the same axis inside the valve body, and can open and close the first valve seat and the second valve seat. A first valve body, a second valve body, a push-pull rod that is connected to the first valve body and the second valve body and pushes and pulls the first valve body and the second valve body, and drives the push-pull rod. And an electric actuator for operating the electric actuator, wherein the electric actuator opens the first valve body by pushing the first valve body through the push-pull rod, and the second valve body through the push-pull rod. To open the second valve body, and move the push-pull rod to an intermediate position where the second valve body is not pulled without pushing the first valve body. It is known that both the body and the second valve body are closed.

When the conventional three-way switching valve is provided in an air conditioner having a refrigeration cycle, the inflow outlet is an indoor unit, the inflow port is a high pressure pipe of an outdoor unit, the outflow port is a low pressure pipe of an outdoor unit, By connecting both the first valve body and the second valve body at the same time, the refrigerant circulation to the indoor unit that does not require air conditioning for cooling and heating can be cut off (for example, the following patents: Reference 1).

JP, 2013-204695, A

By the way, in the conventional three-way switching valve disclosed in Patent Document 1, by changing the length of the push-pull rod for operating (pushing and pulling) the first valve body and the second valve body, the first valve body is changed. It is possible to change and adjust the maximum flow rate when the valve is opened and the maximum flow rate when the second valve body is opened, but since the push-pull rod is connected to the electric actuator as a male screw integrated structure, There is a problem that it is difficult to add processing to the push-pull rod.

Further, since the push-pull rod makes contact with the first valve body and the second valve body while rotating and operates the first valve body and the second valve body, the push-pull rod, the first valve body and the second valve body are operated. The durability of the first valve seat, the second valve seat, etc. on which the first valve body and the second valve body are seated may be reduced.

The present invention has been made in view of the above problems, and an object of the present invention is to make it possible to easily change and adjust the maximum flow rate at the time of opening the valve, and also to have excellent durability. It is to provide a switching valve.

In order to solve the above-mentioned problems, the three-way switching valve according to the present invention basically comprises a valve chamber, a first inlet/outlet opening in the valve chamber, a second inlet/outlet, and a third inlet/outlet, and A valve body having an upper valve seat provided between the first inlet/outlet and the second inlet/outlet, and a lower valve seat provided between the first inlet/outlet and the third inlet/outlet; An upper valve body that is vertically movable in the valve chamber and is in contact with and separated from the upper valve seat; a lower valve body that is vertically movable in the valve chamber and is in contact with and separated from the lower valve seat; and the upper valve. An upper urging member for urging the body in the valve closing direction, a lower urging member for urging the lower valve body in the valve closing direction, and a relative movement in a vertical direction with respect to the upper valve body, and A driven member that is disengageably disposed in the upper valve body so as to separate the upper valve body from the upper valve seat against the biasing force of the upper biasing member, and the biasing force of the lower biasing member. In order to separate the lower valve body from the lower valve seat against the above, the driven member and the lower valve body can be integrally moved, and the driven member and the lower valve body can be relatively moved in the vertical direction. A connecting member for connecting to the driven member and an elevating/lowering drive unit for moving the driven member up and down, and according to the lift amount of the driven member, the upper valve body is seated on the upper valve seat, and the connecting member is The lower valve body is pushed down from the lower valve seat, the upper valve body is seated on the upper valve seat, the lower valve body is seated on the lower valve seat, and the lower valve body is While being seated on the lower valve seat, it is possible to selectively take a state in which the upper valve body is pulled up from the upper valve seat by the driven member, and the lift amount of the driven member is set in advance. Up to the determined first lift amount, the connecting member resists the urging force of the lower urging member while the upper valve body is still seated on the upper valve seat by the urging force of the upper urging member. The lower valve body is pushed down from the lower valve seat, and the lift amount of the driven member exceeds the first lift amount to a predetermined second lift amount by the urging force of the upper urging member. The upper valve body is seated on the upper valve seat, and the lower valve body is seated on the lower valve seat by the urging force of the lower urging member, and the lift amount of the driven member is equal to the second lift amount. When it exceeds, while the lower valve body is seated on the lower valve seat by the urging force of the lower urging member, the upper valve body is opposed to the urging force of the upper urging member by the driven member. Lifted from the upper valve seat It is characterized in that it is to be.

In a preferred aspect, the connecting member is formed of a cylindrical member or a columnar member extending along the ascending/descending direction.

In another preferred aspect, an upper end portion of the connecting member is inserted into the driven member so as to be relatively movable in the up-and-down direction and engageable, and a lower end portion is relatively movable in the up-and-down direction with respect to the lower valve body. Interpolation is possible.

In another preferred aspect, the upper biasing member is interposed between the upper valve body and the driven member.

In another preferred aspect, the upper biasing member is interposed between the upper valve body and the valve body.

In another preferred aspect, the driven member is inserted in the upper valve body so as to be relatively movable in a vertical direction, and is engaged with the upper valve body on the outer periphery of the lower end portion of the driven member according to the lift amount. And an outer brim-shaped locking portion for pulling up the upper valve body from the upper valve seat.

In another preferred aspect, a stopper mechanism that regulates the downward movement of the driven member is configured by the driven member and the upper valve body.

In another preferred aspect, a stopper mechanism that regulates the downward movement of the driven member includes the lower valve body and the valve body.

In another preferred aspect, the chamber diameter of the upper back pressure chamber defined on the upper side of the upper valve body and the aperture of the upper valve seat are set to be the same, and the upper back pressure chamber and the valve chamber are always An upper pressure equalizing passage communicating with the lower valve body is provided, and/or a chamber diameter of a lower back pressure chamber defined below the lower valve body and a bore diameter of the lower valve seat are set to be the same. A lower pressure equalizing passage is provided which constantly connects the back pressure chamber and the valve chamber.

In a further preferred aspect, the upper pressure equalizing passage is configured to include a through hole provided in the coupling member, a communication hole that communicates the through hole with the valve chamber, and the inside of the driven member.

In a further preferred aspect, the upper pressure equalizing passage is constituted by an upper vertical through passage provided inside the upper valve body.

In a further preferred aspect, the lower pressure-equalizing passage is configured to include a through hole provided in the connecting member, a communication hole that communicates the through hole with the valve chamber, and the inside of the lower valve body. ..

In a further preferred aspect, the lower pressure equalizing passage is constituted by a lower longitudinal passage provided inside the lower valve body.

In another preferred aspect, the lifting drive unit includes a stepping motor having a stator mounted on a can fixed to the valve body and a rotor rotatably disposed inside the can, and the rotor. The driven member can be raised and lowered without rotating through a screw feeding mechanism provided between the driven member and the driven member.

In a further preferred embodiment, a planetary gear type speed reduction mechanism that reduces the speed of rotation of the rotor and transmits the rotation is interposed between the rotor and the screw feed mechanism.

According to the flow path switching valve of the present invention, the lift member is moved up and down, and the driven member for separating (pulling) the upper valve body from the upper valve seat against the urging force of the upper urging member and the lower portion. When changing or adjusting the maximum flow rate when opening the valve, the connecting member for separating (pushing down) the lower valve body from the lower valve seat against the urging force of the urging member is configured as a separate component. In addition, for example, since it is only necessary to process the connecting member and the like, it is possible to easily change and adjust the maximum flow rate when the valve is opened, as compared with the conventional one that uses a push-pull rod having an integrated male screw. ..

Further, since the connecting member and the driven member can be raised and lowered without rotating, the durability of the connecting member, the driven member, the lower valve body and the upper valve body, the lower valve seat and the upper valve seat, etc. can be effectively enhanced. You can also

FIG. 3 is a vertical cross-sectional view showing a state where the upper valve body is closed and the lower valve body is open (position where the lift amount is 0) in the first embodiment of the three-way switching valve according to the present invention. FIG. 3 is a vertical cross-sectional view showing a state where the upper valve body is closed and the lower valve body is closed (the lift amount is at the first lift amount position) of the three-way switching valve shown in FIG. 1. FIG. 3 is a vertical cross-sectional view showing a state where the upper valve body is closed and the lower valve body is closed (the lift amount is at the second lift amount position) of the three-way switching valve shown in FIG. 1. FIG. 3 is a vertical cross-sectional view showing a state where the upper valve body is opened and the lower valve body is closed (a position where the lift amount is maximum) of the three-way switching valve shown in FIG. 1. The figure which shows the lift amount of a driven member and the flow volume (opening area) of the three-way switching valve shown in FIG. The longitudinal cross-sectional view which shows the state (position where lift amount is 0) of the upper valve body: closed and the lower valve body: open of the second embodiment of the three-way switching valve according to the present invention. The longitudinal cross-sectional view which shows the state (position of lift amount 0) of the upper valve body: closed and the lower valve body: open of the third embodiment of the three-way switching valve according to the present invention.

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

[First Embodiment]
1 to 4 are longitudinal sectional views showing a first embodiment of a three-way switching valve according to the present invention. FIG. 1 shows a state in which an upper valve body is closed and a lower valve body is open (a lift amount is 0). Position), FIG. 2 is a state in which the upper valve body is closed, and the lower valve body is closed (position where the lift amount is the first lift amount), and FIG. 3 is a state in which the upper valve body is closed and the lower valve body is closed ( The lift amount is the position of the second lift amount), and FIG. 4 shows a state in which the upper valve body is open and the lower valve body is closed (the position where the lift amount is maximum).

In this specification, the description of the position, direction such as up and down, left and right, front and back is added for convenience according to the drawings in order to avoid complicated description, and the position and direction in the actual usage state. Does not necessarily mean.

In addition, in each drawing, the gaps formed between the members and the separation distances between the members are larger than the dimensions of each constituent member in order to facilitate understanding of the invention and for convenience in drawing. Or it may be drawn small.

The three-way switching valve 1 of the illustrated embodiment mainly includes a valve body 5 having a tubular base body 6 made of sheet metal, a can 58 fixed to the valve body 5, and an internal space defined by the valve body 5 and the can 58. A support member 19 fixedly arranged on the valve body 5, an upper valve body 20 and a lower valve body 70 arranged to be able to move up and down in the internal space, and a driven member arranged to be engageable with the upper valve body 20. 60, a connecting rod (connecting member) 65 that connects the driven member 60 and the lower valve body 70, a stepping motor (elevating drive unit) 50 mounted above the valve body 5 to raise and lower the driven member 60, Is equipped with.

A metallic lid-shaped member 6A, for example, is hermetically attached to the lower opening of the tubular base body 6 of the valve body 5 by welding, caulking, brazing or the like, and a valve chamber 7 is defined therein. A lateral inlet (second inlet/outlet) 11a and an outlet (third inlet/outlet) 12a that open to the valve chamber 7 are formed on the side of the inlet 11a so as to be separated from each other in the axis O direction (elevating direction). A sideways inlet/outlet (first inlet/outlet) 10a is formed between the inlet and outlet 12a. The conduit joints 10, 11, and 12 are attached to the inlet/outlet 10a, the inlet 11a, and the outlet 12a by brazing or the like.

In this example, the inlet/outlet 10a, the inlet 11a, and the outlet 12a are formed on the opposite side (with an angular interval of 180 degrees) when viewed in a plan view (that is, the axis O direction). However, it goes without saying that the positions of the inlet/outlet 10a, the inlet 11a, and the outlet 12a in the circumferential direction can be appropriately changed.

In addition, a thick-walled cylindrical valve seat member 8 having a communication port 8a communicating with the inlet/outlet port 10a is welded to the inner periphery of the tubular body 6 of the valve body 5 between the inlet port 11a and the outlet port 12a. It is inserted and fixed by caulking, brazing, etc.

The valve seat member 8 is made of, for example, a metal material such as SUS, and an upper end side opening thereof is an upper valve seat 9a, a lower end side opening thereof is a lower valve seat 9b, and the communication port is formed in the middle abdomen thereof. 8a is formed. Further, an upper taper surface 9c and a lower taper surface 9d which are connected to the upper valve seat 9a and the lower valve seat 9b are formed at the upper end and the lower end of the valve seat member 8. Here, the diameter φa of the upper valve seat 9a and the lower valve seat 9b (that is, the inner diameter of the cylindrical valve seat member 8) is the chamber diameter φb of the upper back pressure chamber 30 defined on the upper side of the upper valve body 20. , And the chamber diameter φc of the lower back pressure chamber 80 defined below the lower valve body 70 (detailed later).

A stepped tubular base 13 is attached to an upper opening of the tubular base 6 of the valve body 5, and a lower surface of the tubular base 13 forms a ceiling surface of the valve chamber 7. The lower end of a cylindrical can 58 with a ceiling is joined to the outer periphery of the upper end of the cylindrical base 13 by welding or the like.

The support member 19 has a tubular holding member 14 with a partition wall 14c and a bearing member 15 with a female screw 15i, and the tubular holding member 14 is a portion below the partition wall 14c inside the tubular base 13. The sleeve portion 14d, which is cylindrical and has a downward opening, is fixed to the valve chamber 7 by press fitting or the like. A cylindrical bearing member 15 having an internal thread 15i screwed on the lower half of the inner circumference is fixed to the upper portion of the cylindrical holding member 14 by caulking or the like. A spring chamber 14a is defined between the partition wall 14c of the cylindrical holding member 14 and the bearing member 15, and the compression coil spring 25 that biases the driven member 60 upward is housed in the spring chamber 14a. .. A portion of the inner periphery of the bearing member 15 above the female screw 15i is a fitting insertion hole 15a into which a lower portion of an output shaft 46 of the speed reduction mechanism 40 described later is fitted.

On the other hand, the stepping motor 50 is arranged inside the can 58 so as to be rotatable with respect to the can 58 and a stator 55 including a yoke 51, a bobbin 52, a coil 53, a resin mold cover 54, etc. And a rotor 57 fixed to the inside of the upper part. The stator 55 is externally fitted and fixed to the can 58. Further, on the inner peripheral side of the rotor 57, the sun gear 41 integrally formed with the rotor support member 56 and the fixed ring gear 47 fixed to the upper end of the tubular body 43 fixed to the upper portion of the tubular holding member 14. , A planetary gear 42 arranged between the sun gear 41 and the fixed ring gear 47 and meshing with each other, a carrier 44 rotatably supporting the planetary gear 42, and a bottomed ring shape meshing with the planetary gear 42 from the outside. The mysterious planetary gear type speed reduction mechanism 40 including the output gear 45, the output shaft 46 and the like, the upper portion of which is fixed to the hole formed in the bottom portion of the output gear 45 by press fitting or the like. Here, the number of teeth of the fixed ring gear 47 is set to be slightly different from the number of teeth of the output gear 45.

A hole is formed in the center of the upper portion of the output shaft 46, and the lower portion of the support shaft 49, which passes through the center portion of the sun gear 41 (rotor supporting member 56) and the carrier 44, is inserted through the hole. The upper portion of the support shaft 49 has an outer diameter that is substantially the same as the inner diameter of the can 58, and is formed in a hole formed in the center of a support member 48 that is inscribed in the can 58 above the rotor support member 56. It has been inserted. The rotor 57 itself is prevented from moving up and down inside the can 58 by the support member 48 and the like, and the positional relationship with the stator 55 fitted and fixed to the can 58 is always kept constant.

The lower portion of the output shaft 46 of the reduction mechanism 40 is rotatably fitted in a fitting hole 15a formed in the upper portion of the bearing member 15 with the female screw 15i, and the lower portion of the output shaft 46 is laterally passed through the center thereof. A slit-shaped fitting portion 46a extending in the direction is formed. A plate-shaped portion 17c is projectingly provided at the upper end of the rotary lifting shaft 17 having a male screw 17a screwed on the inner periphery of the bearing member 15 and a male screw 17a screwed therewith. The mating portion 46a is slidably fitted. When the output shaft 46 rotates in accordance with the rotation of the rotor 57, the rotation of the output shaft 46 is transmitted to the rotary elevating shaft 17, and is rotated by the screw feed mechanism including the female screw 15i of the bearing member 15 and the male screw 17a of the rotary elevating shaft 17. The elevating shaft 17 moves up and down while rotating.

Below the rotary elevating shaft 17, the thrust force of the rotary elevating shaft 17 is transmitted through the ball 18 and the ball seat 16 to the stepped cylindrical thrust force transmitting shaft 23 and the substantially cylindrical driven member 60. Are integrally arranged along the axis O (up and down direction). By interposing the ball 18 between the rotary lifting shaft 17 and the thrust transmission shaft 23, for example, even when the rotary lifting shaft 17 descends while rotating, the thrust transmission shaft 23 (and the driven member) is rotated from the rotary lifting shaft 17 (and the driven member). Only the downward thrust is transmitted to 60), and the rotational force is not transmitted.

Here, as described above, the compression coil spring 25 housed in the spring chamber 14a above the partition wall 14c of the tubular holding member 14 is arranged with its lower end abutted against the partition wall 14c, and In order to transmit the urging force (pulling force) of the compression coil spring 25 to the thrust transmission shaft 23 (and the driven member 60), a pulling spring receiving body 28 having upper and lower brim-shaped hooking portions is arranged. The upper hook of the pull-up spring receiver 28 is placed on the upper portion of the compression coil spring 25, and the lower hook is hooked on the thrust transmission shaft 23 (the lower end step surface of the large diameter upper portion 23a). In addition, the cylindrical holding member 14 is formed with a communication hole 14e that connects the spring chamber 14a and the inside of the can 58.

The thrust transmission shaft 23 includes, from the upper side, a large diameter upper portion 23a into which the ball seat 16 is fitted on the inner periphery, an intermediate body portion 23b inserted into a central hole formed in the partition wall 14c of the tubular holding member 14, and an intermediate body. It is composed of a small-diameter lower portion 23c having a diameter smaller than that of the portion 23b, and the inside thereof is opened to a vertical hole 23d formed of a vertically oriented through hole which constitutes an upper portion of an upper pressure equalizing passage 31 described later and an upper back pressure chamber 30 described later. A plurality of lateral holes 23e are formed. The upper end opening of the vertical hole 23d is closed by the ball seat 16.

The center hole 61 of the driven member 60 disposed below the thrust transmission shaft 23 is formed with steps, and the small diameter lower portion 23c of the thrust transmission unit shaft 23 is an upper large fitting hole of the center hole 61 of the driven member 60. The driven member 60 and the thrust transmission shaft 23 are integrally lifted up and down by press-fitting or the like to the 61a. Between the upper end surface of the driven member 60 and the lower end step portion of the intermediate body portion 23b of the thrust transmission shaft 23, when the small-diameter lower portion 23c is press-fitted, a spring bearing of an upper valve closing spring 20A (upper end) to be described later and a follower A collar-shaped member 62 made of a thick disk that also serves as one of the stopper functions that regulates the downward movement of the member 60 (in other words, defines the lower limit position of the driven member 60) is sandwiched and fixed.

Further, the outer periphery of the lower end portion of the driven member 60 is engaged with (the lower surface of) the upper valve body 20 slidably inserted into the driven member 60 to prevent the upper valve body 20 from coming off and locking (that is, , An outer brim-shaped locking portion 63 for pulling up the upper valve body 20 (projected outward).

Further, an upper end portion of a cylindrical connecting rod 65, which will be described later, is fitted (from the lower side) into the lower large-diameter insertion hole 61b of the center hole 61 of the driven member 60 and slidable (in other words, relatively movable). ), and the upper end step (face) of the connecting rod 65 abuts on the upper end step portion of the lower large-diameter insertion hole 61b.

The upper valve body 20 is formed in a stepped cylindrical shape, and the lower portion thereof can be slid on the sleeve portion 14d in the direction of the axis O (elevating direction) by protruding from the sleeve portion 14d of the tubular holding member 14. The driven member 60 is fitted (from the lower side) inside and slidable (that is, relatively movable) in the direction of the axis O (elevating direction) and the outer brim-shaped locking portion 63. It is locked by the stopper and inserted. In other words, the upper valve body 20 is slidably inserted between the collar-shaped member 62 and the outer collar-shaped locking portion 63 of the driven member 60 so as to be slidable in the direction of the axis O (up and down direction). A pressing member 21 is fixed by caulking or the like to a step portion provided on the outer periphery of the upper end of the upper valve body 20, and the pressing member 21 and the step portion formed on the upper outer periphery of the upper valve body 20 are formed. An O-ring for sealing a gap between (the outer peripheral surface of) the upper valve body 20 and (the inner peripheral surface of) the sleeve portion 14d in the annular groove (a sliding surface gap formed therein), made of Teflon (registered trademark) A seal member 22 including a cap seal or the like is attached.

In addition, the upper valve body 20 is directed downward (in the valve closing direction) between the inner peripheral stepped portion (terrace surface) 20a formed on the inner periphery of the upper surface of the upper valve body 20 and the lower surface of the collar member 62. An upper valve closing spring 20A made up of a compression coil spring is interposed (compressed) as an upper urging member for urging, and at the center of the upper surface of the upper valve body 20 (around the upper valve closing spring 20A). , A cylindrical stopper convex portion 20b that constitutes the other of the stopper functions for restricting the downward movement of the driven member 60 together with the collar-shaped member 62 (specifically, in contact with the collar-shaped member 62) is projected (upward). It is set up.

Here, the lower end outer peripheral portion of the upper valve body 20 is an upper valve body portion that is seated on the upper valve seat 9a of the valve seat member 8 (from the upper side).

On the other hand, in the present example, the lower valve body 70 is formed to have an approximately same diameter as the upper valve body 20 and an outer shape in which the upper valve body 20 is turned upside down. The lid-like member 6A of the valve body 5 is provided with a cylindrical sleeve portion 6d having an upward opening protruding upward (toward the valve chamber 7 side), and the lower valve body 70 has an upper portion thereof covered with the lid-like member. It is slidably inserted in the sleeve portion 6d so as to protrude from the sleeve portion 6d of 6A in the direction of the axis O (elevating direction). This lower valve body 70 has a stepped central hole 70a penetrating along the axis O direction (elevating direction), and the upper large-diameter insertion hole 70b of the central hole 70a has a cylindrical shape described later. The lower end of the connecting rod 65 is fitted (from the upper side) and slidably inserted (in other words, relatively movable), and the lower end of the connecting rod 65 is inserted into the lower step portion of the upper large-diameter insertion hole 70b. The parts (faces) are in contact with each other. A pressing member 71 is fixed by caulking or the like to a step portion provided on the lower end outer periphery of the lower valve body 70, and is formed by the pressing member 71 and the step portion formed on the lower outer periphery of the lower valve body 70. An O-ring for sealing the gap between (the outer peripheral surface of) the lower valve body 70 and (the inner peripheral surface of) the sleeve portion 6d in the annular groove, which is made of Teflon (registered trademark). A seal member 72 including a cap seal or the like is attached.

Further, between the pressing member 71 (the lower surface thereof) fixed to the lower valve body 70 and the lid-shaped member 6A (the outer peripheral portion of the upper surface thereof), a lower portion that urges the lower valve body 70 upward (in the valve closing direction). A lower valve closing spring 70A, which is a compression coil spring as an urging member, is interposed (compressed).

Here, the upper end outer peripheral portion of the lower valve body 70 is a lower valve body portion that is seated on the lower valve seat 9b of the valve seat member 8 (from below).

Between the driven member 60 and the lower valve body 70, a connecting rod 65 formed of a cylindrical member is inserted so as to insert the inside of the valve seat member 8 along the axis O direction (elevating direction). It is distributed. As described above, the upper end portion of the connecting rod 65 is slidably fitted in the lower large-diameter fitting insertion hole 61b of the center hole 61 of the driven member 60, and the lower end portion thereof has the central hole 70a of the lower valve body 70. Is slidably fitted in the upper large-diameter fitting insertion hole 70b, and the driven member 60 and the lower valve body 70 are relatively movable in the axis O direction (up and down direction) via the connecting rod 65. There is. Further, the upper end portion of the connecting rod 65 abuts and engages with (following the upper end step portion of the lower large-diameter insertion hole 61b of) the driven member 60, and the lower end portion of the connecting rod 65 (the upper portion of the lower valve body 70). It contacts and engages with the lower end step portion of the large-diameter insertion hole 70b), which allows the driven member 60 and the lower valve body 70 to move integrally via the connecting rod 65. (Detailed later).

In addition, in the central portion (direction of the axis O) of the connecting rod 65, a plurality of (may be one) communicating the vertical through hole 66 provided inside the connecting rod 65 and the valve chamber 7 with each other. A communication hole 67 composed of a lateral hole is opened.

In this example, the upper end of the connecting rod 65 is slidably fitted in the lower large-diameter fitting hole 61b of the center hole 61 of the driven member 60, and the lower end thereof is in the central hole of the lower valve body 70. The driven member 60 and the lower valve body 70 are slidably fitted in the upper large-diameter insertion hole 70b of 70a, but the driven member 60 and the lower valve body 70 are relatively movable in the axis O direction (elevating direction) via the connecting rod 65. Moreover, it is only necessary that the connecting rod 65 can be integrally moved via the connecting rod 65. For example, only (the upper end portion of) the connecting rod 65 may be fixed to (the center hole 61 of) the driven member 60, or conversely, It goes without saying that only (the lower end portion of) the connecting rod 65 may be fixed to (the central hole 70a of) the lower valve body 70.

The lateral hole 23e and the vertical hole 23d of the thrust transmission shaft 23, the central hole 61 of the driven member 60, the upper half of the through hole 66 of the connecting rod 65, and the communication hole 67 define the upper side of the upper valve body 20. An upper back pressure chamber 30 (specifically, a space surrounded by the upper valve body 20, the sleeve portion 14d, and the partition wall 14c) and an upper pressure equalizing passage 31 that communicates with the valve chamber 7 are configured. In addition, the lower back pressure chamber 80 defined below the lower valve body 70 by the central hole 70a of the lower valve body 70, the lower half of the through hole 66 of the connecting rod 65, and the communication hole 67 (specifically, A lower pressure equalizing passage 81 that communicates the lower valve body 70, the space surrounded by the sleeve portion 6d, the lid-shaped member 6A) and the valve chamber 7 is configured. Further, in order to balance the pushing down force and the pushing up force acting on the upper valve body 20 in the valve closed state (canceling the differential pressure), the chamber diameter φb of the upper back pressure chamber 30 (that is, the inner diameter of the sleeve portion 14d) is The diameter φa of the upper valve seat 9a (that is, the inner diameter of the cylindrical valve seat member 8) is set to be substantially the same, and the pushing force and the pushing force acting on the lower valve body 70 in the valve closed state are balanced (differential pressure). The chamber diameter φc of the lower back pressure chamber 80 (that is, the inner diameter of the sleeve portion 6d) is substantially the same as the bore diameter φa of the lower valve seat 9b (that is, the inner diameter of the cylindrical valve seat member 8). Is set to.

In the three-way switching valve 1 having such a configuration, when the rotor 57 of the stepping motor 50 is rotationally driven, the rotary elevating shaft 17 moves up and down while rotating, but between the rotary elevating shaft 17 and the thrust transmission shaft 23 and the driven member 60. By interposing the ball 18, only the downward thrust force is transmitted from the rotary lift shaft 17 to the thrust transmission shaft 23 and the driven member 60 (the rotation force is not transmitted), and the rotary lift shaft 17, the thrust transmission shaft 23 and the driven member are driven. Together with the member 60, it moves up and down in the direction of the axis O. As a result, the upper valve body 20 mounted on the driven member 60 and the lower valve body 70 connected to the driven member 60 via the connecting rod 65 come into contact with and separate from the upper valve seat 9a and the lower valve seat 9b of the valve seat member 8. Thus, the flow direction (flow path) between the inlet/outlet 10a, the inlet 11a, and the outlet 12a is switched.

More specifically, in the three-way switching valve 1 of this embodiment, the lift amount (valve opening) of the driven member 60 (and the upper valve body 20 and the lower valve body 70) as shown in FIG. In the state (in other words, at the lowermost position), the collar-shaped member 62 of the driven member 60 abuts on the stopper protrusion 20b of the upper valve body 20, and the upper valve body 20 (the upper valve body portion thereof) becomes the upper valve. The upper end opening of the valve seat member 8 is closed by being seated on the seat 9a (more specifically, pressed by the urging force of the upper valve closing spring 20A), and the upper end step portion of the lower large-diameter insertion hole 61b of the upper valve body 20 is closed. Comes into contact with the upper end of the connecting rod 65, and the lower end of the connecting rod 65 comes into contact with the lower end step portion of the upper large-diameter insertion hole 70b of the lower valve body 70, and resists the urging force of the lower valve closing spring 70A. The lower valve body 70 (the lower valve body portion thereof) is separated from the lower valve seat 9b, the lower end opening of the valve seat member 8 is opened, and the fluid (refrigerant) flows from the conduit joint 10 connected to the inlet/outlet 10a to the valve seat. Through the communication port 8a of the member 8→the inside of the valve seat member 8→the lower end opening of the valve seat member 8 (the lower valve seat 9b), it is flowed to the conduit joint 12 connected to the outlet 12a. When the lift amount of the driven member 60 is 0, the flow rate of the fluid (refrigerant) flowing into the outlet 12a is maximum (see FIG. 5). At this time, the lower valve body 70 (the lower valve body thereof) and the lower valve seat 9b are positioned so as to be separated from each other by the first lift amount L1 in the direction of the axis O (elevating direction), and the driven member 60 is locked with the outer flange. The portion 63 (upper surface of the upper valve body) and the upper surface of the upper valve body 20 (lower surface thereof) are positioned apart from each other by the second lift amount L2 in the direction of the axis O (up and down direction), and the second lift amount L2 is larger than the first lift amount L1. The size and shape of each part are set to be large.

When the rotor 57 of the stepping motor 50 is rotationally driven in one direction from the state shown in FIG. 1, the rotation of the rotor 57 is decelerated and transmitted to the rotary lifting shaft 17 via the output shaft 46 of the speed reduction mechanism 40, and the bearing By the screw feed by the female screw 15i of the member 15 and the male screw 17a of the rotary lift shaft 17, the rotary lift shaft 17 is raised while rotating, and the driven member 60 is pulled up together with the rotary lift shaft 17 accordingly. When the driven member 60 is raised, as shown in FIG. 2, the upper valve body 20 (the upper valve body portion) of the upper valve body 20 is urged by the urging force of the upper valve closing spring 20A up to the first lift amount L1. The driven member 60 is slidably moved in the upper valve body 20 while the valve seat member 8 is seated and the upper end opening of the valve seat member 8 is closed. At this time, since the length of the upper valve closing spring 20A (in the direction of the axis O) gradually increases, the sealing property (pressing force) of the upper valve body 20 against the upper valve seat 9a gradually weakens. At the same time, the lower valve body 70 connected to the driven member 60 via the connecting rod 65 is raised (along with the driven member 60) by the urging force of the lower valve closing spring 70A, and the fluid (refrigerant flowing into the outlet 12a ) Gradually decreases (see FIG. 5) and the lift amount of the driven member 60 reaches the first lift amount L1, the lower valve body 70 (the lower valve body portion thereof) moves to the lower valve seat 9b (lower side). (From the bottom), the seat is seated (specifically, it is pressed against the urging force of the lower valve closing spring 70A), and the lower end opening of the valve seat member 8 is closed. At this time, the outer brim-shaped locking portion 63 (the upper surface) of the driven member 60 and the upper valve body 20 (the lower surface) are positioned so as to be separated from each other by L2-L1 in the direction of the axis O (up and down direction).

After the driven member 60 is raised to the first lift amount L1, the driven member 60 is further raised, and as shown in FIG. 3, the upper valve closing spring 20A is attached until the second lift amount L2. The upper valve body 20 (the upper valve body portion thereof) is seated on the upper valve seat 9a by the urging force, the upper end opening of the valve seat member 8 is closed, and the lower valve body 70 is urged by the urging force of the lower valve closing spring 70A. (The lower valve body portion of the valve seat) is seated on the lower valve seat 9b and the lower end opening of the valve seat member 8 is kept closed, and the driven member 60 is inside the upper valve body 20 and outside (the upper end portion) of the connecting rod 65. When the lift amount of the driven member 60 reaches the second lift amount L2, the outer brim-shaped engaging portion 63 of the driven member 60 is engaged with the upper valve body 20. Also at this time, the length of the upper valve closing spring 20A (in the direction of the axis O) gradually increases.

After the driven member 60 is raised to the second lift amount L2 and then the driven member 60 is further raised, as shown in FIG. 4, the outer brim-shaped locking portion 63 of the driven member 60 causes the upper valve body 20 to move. The lower valve body 70 (the lower valve body portion thereof) is seated on the lower valve seat 9b by the urging force of the lower valve closing spring 70A, and the lower end opening of the valve seat member 8 remains closed, while the upper valve body is closed. 20 is moved (elevated) together with the driven member 60, the upper valve body 20 (the upper valve body portion thereof) is separated from the upper valve seat 9a, the upper end opening of the valve seat member 8 is opened, and the fluid ( Refrigerant) enters from the conduit joint 11 connected to the inflow port 11a through the upper end opening (upper valve seat 9a) of the valve seat member 8 →the inside of the valve seat member 8 →the communication port 8a of the valve seat member 8. It is flowed to the conduit fitting 10 connected to the outlet 10a. As the driven member 60 rises, the upper valve body 20 (the lower valve body portion thereof) is further separated from the upper valve seat 9a, and the flow rate of the fluid (refrigerant) flowing into the inlet/outlet 10a gradually increases. When the lift amount reaches the maximum lift amount Lmax (that is, when the upper valve body 20 (the upper valve body portion thereof) is located away from the upper valve seat 9a by Lmax-L2 in the direction of the axis O (up and down direction)). The flow rate of the fluid (refrigerant) flowing into the inlet/outlet 10a also becomes maximum (see FIG. 5). At this time, the length of the upper valve closing spring 20A (in the direction of the axis O) is constant and does not change.

On the other hand, when the rotor 57 of the stepping motor 50 is rotationally driven in the other direction, the rotation of the rotor 57 is decelerated and transmitted to the rotary lifting shaft 17 via the output shaft 46 of the reduction mechanism 40, and the female screw 15i and the male screw 17a are transmitted. The rotary elevating shaft 17 is rotated and lowered by the screw feed by the screw feeding, and the driven member 60 is pushed down together with the rotary elevating shaft 17 against the biasing force of the compression coil spring 25 by the thrust of the rotary elevating shaft 17. When the driven member 60 is lowered, contrary to the above, the lower valve body 70 (the lower valve body portion thereof) is seated on the lower valve seat 9b by the urging force of the lower valve closing spring 70A, and the valve seat member 8 is moved. The upper valve body 20 (the upper valve body portion thereof) is seated on the upper valve seat 9a (from the upper side) while the lower end opening of the valve seat member 8 is closed, and the upper end opening of the valve seat member 8 is closed. When it is further lowered, the upper valve body 20 (the upper valve body portion thereof) is seated on the upper valve seat 9a by the urging force of the upper valve closing spring 20A, and the upper end opening of the valve seat member 8 remains closed, while the lower part is closed. The lower valve body 70 (the lower valve body portion thereof) is separated from the lower valve seat 9b against the biasing force of the valve spring 70A, and the lower end opening of the valve seat member 8 is opened. Note that when the upper valve body 20 (the upper valve body portion thereof) is seated on the upper valve seat 9a (from the upper side) and the upper end opening of the valve seat member 8 is closed, the driven member 60 is further lowered. The length of the upper valve closing spring 20A (in the direction of the axis O) interposed between the collar-shaped member 62 of the member 60 and the upper valve body 20 is gradually shortened (that is, compressed). The sealing property (pressing force) of the above with respect to the upper valve seat 9a gradually becomes stronger.

Here, in the present embodiment, when (the upper valve body portion of) the upper valve body 20 is seated on the upper valve seat 9a (the state shown in FIGS. 1 to 3), from the through hole 66 of the connecting rod 65 and the like. The upper back pressure chamber 30 defined on the upper side of the upper valve body 20 and the valve chamber 7 are always communicated with each other via the upper pressure equalizing passage 31. In other words, the upper surface of the upper valve body 20 (the surface on the upper back pressure chamber 30 side) and the lower surface of the upper valve body 20 (the surface on the valve chamber 7 side) are equalized. Further, the chamber diameter φb of the upper back pressure chamber 30 (that is, the inner diameter of the sleeve portion 14d) and the bore diameter φa of the upper valve seat 9a (that is, the inner diameter of the cylindrical valve seat member 8) are set to be substantially the same. There is.

Therefore, when the flow paths are switched by moving the upper valve body 20 in the direction of the axis O, the forces acting in the moving direction of the upper valve body 20 (the pushing-down force and the pushing-up force acting on the upper valve body 20) are balanced (all differential pressures are Since it is canceled, the load acting on the upper valve body 20 at the time of switching the flow path can be reduced as much as possible, and the driving torque by the stepping motor 50 can be reduced.

Similarly, when the lower valve body 70 (the lower valve body portion thereof) is seated on the lower valve seat 9b (the state shown in FIGS. 2 to 4), the lower pressure equalizing passage including the through hole 66 of the connecting rod 65 and the like. The lower back pressure chamber 80 defined below the lower valve body 70 and the valve chamber 7 are always communicated with each other via 81. In other words, the lower surface of the lower valve body 70 (the surface on the lower back pressure chamber 80 side) and the upper surface of the lower valve body 70 (the surface on the valve chamber 7 side) are pressure-equalized. Further, the chamber diameter φc of the lower back pressure chamber 80 (that is, the inner diameter of the sleeve portion 6d) and the bore diameter φa of the lower valve seat 9b (that is, the inner diameter of the cylindrical valve seat member 8) are set to be substantially the same. There is.

Therefore, when the flow paths are switched by the movement of the lower valve body 70 in the axis O direction, the forces acting in the moving direction of the lower valve body 70 (the pushing force and the pushing force acting on the lower valve body 70) are balanced (all differential pressures are Since it is canceled, the load acting on the lower valve body 70 at the time of switching the flow path can be reduced as much as possible, and the driving torque by the stepping motor 50 can be reduced.

Further, in the three-way switching valve 1 of the present embodiment, the stepping motor 50 raises and lowers the driven valve for separating (pulling up) the upper valve body 20 from the upper valve seat 9a against the biasing force of the upper valve closing spring 20A. Since the member 60 and the connecting rod 65 for separating (pushing down) the lower valve body 70 from the lower valve seat 9b against the biasing force of the lower valve closing spring 70A are configured as separate parts, it is possible to When the maximum flow rate is changed/adjusted, for example, the connecting rod 65 and the like need to be processed (see FIG. 5). Therefore, for example, compared with the conventional valve using a push-pull rod with an external thread, the valve can be opened. The maximum flow rate can be easily changed and adjusted.

In addition to the connecting rod 65 or in place of the connecting rod 65, the driven member 60, the upper valve body 20, and the lower valve body 70 are changed in shape and size to change the maximum flow rate when the valve is opened. Adjustments may be made.

Further, since the connecting rod 65 and the driven member 60 can be raised and lowered without rotating, the connecting rod 65, the driven member 60, the lower valve body 70, the upper valve body 20, the lower valve seat 9b, the upper valve seat 9a, etc. It can also effectively increase durability.

Further, in the three-way switching valve 1 of the present embodiment, as described above, the upper valve closing spring 20A is provided between the upper valve body 20 and the flange-shaped member 62 of the driven member 60 which is moved up and down with respect to the valve body 5. Since it is interposed, the sealing property (pressing force) of the upper valve body 20 against the upper valve seat 9a can be effectively enhanced.

[Second Embodiment]
FIG. 6 shows a second embodiment of the three-way switching valve according to the present invention.

The three-way switching valve 2 of the second embodiment is different from the three-way switching valve 1 of the first embodiment in that the upper valve closing spring 20A that biases the upper valve body 20 mainly in the valve closing direction and the driven member 60 ( That is, the arrangement configuration of the stopper mechanism that regulates the lower movement of the lower valve body 70) is different, and the other configurations are substantially the same. Therefore, the portions corresponding to the respective portions of the first embodiment will be denoted by the common reference numerals, and the duplicate description will be omitted, and the differences will be mainly described below.

In the three-way switching valve 2 of the second embodiment, the flange-shaped member 62, which also serves as a spring receiver for (upper end of) the upper valve closing spring 21 and a stopper function for regulating the downward movement of the driven member 60, is omitted, and the upper valve The upper valve body 20 faces downward (closed) between (the upper surface of) the pressing member 21 fixed to the outer periphery of the upper end of the body 20 and (the outer peripheral portion of the partition 14c of the tubular holding member 14 fixed to the valve body 5). An upper valve closing spring 20A, which is a compression coil spring as an upper urging member for urging in the valve direction), is interposed (compressed).

Further, a cylindrical movable stopper convex portion 70c having a slightly smaller diameter, which constitutes one of the stopper functions for regulating the downward movement of the driven member 60, is provided (downward) at the central portion of the lower surface of the lower valve body 70, and the valve main body is provided. A cylindrical fixed stopper convex portion 6c having a slightly larger diameter, which constitutes the other of the above-mentioned stopper functions, is provided (upward) at the central portion of the upper surface of the lid-shaped member 6A of No. 5, together with the driven member 60 depending on the lift amount. When the lower valve body 70 descends, the movable stopper protrusion 70c contacts the fixed stopper protrusion 6c, and the lift amount (valve opening) of the driven member 60 (and the upper valve body 20 and the lower valve body 70) increases. The state of 0 (in other words, the lowest position) can be taken.

In the present embodiment, the lower surface central portion of the lower valve body 70 (the movable stopper convex portion 70c thereof) contacts the upper surface central portion (the fixed stopper convex portion 6c) of the lid-shaped member 6A of the valve body 5, so that the lower portion The movable stopper projection 70c of the valve body 70 is provided with a plurality of (may be one) lateral holes 70d for communicating the central hole 70a with the lower back pressure chamber 80. The hole 70a, the lower half of the through hole 66 of the connecting rod 65, and the communication hole 67 form a lower pressure equalizing passage 81 that connects the lower back pressure chamber 80 and the valve chamber 7.

Further, in the present embodiment, in addition to the above configuration, the communication hole 67 that communicates the through hole 66 of the connecting rod 65 with the valve chamber 7 is provided in order to suppress the generation of noise when a fluid (refrigerant) passes. Instead of the central portion (direction of the axis O) of the connecting rod 65 as in the first embodiment (that is, the position facing the inlet/outlet 10a), the upper and lower portions of the connecting rod 65 (direction of the axial O), more specifically, It is provided in a portion located inside the recessed hole 20B provided in the lower surface of the upper valve body 20 and the recessed hole 70B provided in the upper surface of the lower valve body 70.

In the three-way switching valve 2 of the second embodiment having such a configuration, unlike the three-way switching valve 1 of the first embodiment described above, the upper valve closing spring 20A has a pressing member fixed to the outer periphery of the upper end of the upper valve body 20. Since it is interposed between the member 21 and the cylindrical holding member 14 fixed to the valve main body 5, when the rotor 57 of the stepping motor 50 is rotationally driven in one direction and the driven member 60 is raised, Above the first lift amount L1 (see FIG. 2) and up to the second lift amount L2 (see FIG. 3), the upper valve body 20 (the upper valve body portion thereof) is seated on the upper valve seat 9a and the valve seat member 8 With the upper end opening kept closed, the length of the upper valve closing spring 20A (in the direction of the axis O) does not change (that is, the sealing property (pressing force) of the upper valve body 20 against the upper valve seat 9a does not change). However, when the second lift amount L2 is exceeded, the upper valve body 20 (the upper valve body portion thereof) is separated from the upper valve seat 9a by the outer brim-shaped locking portion 63 of the driven member 60, and the upper end opening of the valve seat member 8 is opened. Is opened, and the length of the upper valve closing spring 20A (in the direction of the axis O) gradually becomes shorter (that is, compressed).

Also in the three-way switching valve 2 of the second embodiment having such a configuration, since the driven member 60 and the connecting rod 65 are configured as separate parts, the same operational effect as the three-way switching valve 1 of the first embodiment described above. In addition to that, there is an effect that the configuration around the upper valve body 20 can be simplified.

[Third Embodiment]
FIG. 7 shows a third embodiment of the three-way switching valve according to the present invention.

The three-way switching valve 3 of the third embodiment is different from the three-way switching valve 2 of the second embodiment mainly in the arrangement configuration of the upper pressure equalizing passage 31 and the lower pressure equalizing passage 81. The configuration is almost the same. Therefore, the portions corresponding to the respective portions of the second embodiment will be denoted by the common reference numerals, and the duplicate description will be omitted. Below, the different points will be mainly described.

In the three-way switching valve 3 of the third embodiment, the lateral hole 23e of the thrust transmission shaft 23, the central hole 61 of the driven member 60 (the lower large-diameter insertion hole 61b into which the upper end of the connecting rod 65 is relatively movable) is inserted. Other parts), the lateral hole 70d of the lower valve body 70, the central hole 70a (the part other than the upper large-diameter insertion hole 70b into which the lower end of the connecting rod 65 is relatively movably inserted), and the like, and The connecting rod 65 is configured by a cylindrical member (in other words, a solid member) that is long in the direction of the axis O (up and down direction) instead of the cylindrical member (in other words, hollow member).

Further, in order to connect the upper back pressure chamber 30 and the valve chamber 7 to each other, a plurality of (may be one) upper vertical through passages 20e vertically penetrating the upper valve body 20 are provided, and the lower back pressure chamber is also formed. In order to communicate 80 with the valve chamber 7, a plurality of (may be one) lower vertical through passages 70e that vertically penetrate the lower valve body 70 are provided, and are provided inside the upper valve body 20. The upper vertical passage 20e constitutes the upper pressure equalizing passage 31, and the lower vertical passage 70e provided inside the lower valve body 70 constitutes the lower pressure equalizing passage 81.

Also in the three-way switching valve 3 of the third embodiment having such a configuration, since the driven member 60 and the connecting rod 65 are configured as separate parts, the three-way switching valves 1, 2 of the first and second embodiments described above. In addition to the same effects and advantages as described above, there is an effect that the configurations of the driven member 60 and the connecting rod 65 can be simplified and downsized (for example, reduced in diameter). Although a rod-shaped member having a circular cross section is used for the connecting rod 65 of the present embodiment, a plate-shaped member having a rectangular cross section or an elliptical cross section may be used. In this case, the pressure loss when the refrigerant passes through the valve chamber 7 can be reduced.

In the above embodiment, the inlet/outlet (first inlet/outlet) 10a is an indoor unit of an air conditioner having a refrigeration cycle, the inlet (second inlet/outlet) 11a is a high-pressure pipe of an outdoor unit, and the outlet (first). 3 inlet/outlet) 12a is connected to the low-pressure pipe of the outdoor unit, respectively, and the fluid (refrigerant) flows from the inlet (second inlet/outlet) 11a (conduit joint 11 thereof) to the inlet/outlet (first inlet/outlet) 10a (of). The case where the flow is toward the conduit joint 10) or from the inlet/outlet (first inlet/outlet) 10a (the conduit joint 10 thereof) toward the outlet (third inlet/outlet) 12a (the conduit joint 12 thereof) is illustrated. As described above, switching of the flow direction (flow path) of the fluid (refrigerant) between the inlet/outlet (first inlet/outlet) 10a, the inlet (second inlet/outlet) 11a, and the outlet (third inlet/outlet) 12a. Of course, it is not limited to this.

1 Three-way switching valve (first embodiment)
2 Three-way switching valve (second embodiment)
3 Three-way switching valve (third embodiment)
5 Valve body 6 Cylindrical base 6c Fixed stopper protrusion (second embodiment)
6d sleeve part 7 valve chamber 8 valve seat member 9a upper valve seat 9b lower valve seats 10, 11, 12 conduit joint 10a inlet/outlet (first inlet/outlet)
11a Inlet (second inlet/outlet)
12a Outlet (third inlet/outlet)
14 cylindrical holding member 14c partition wall 14d sleeve portion 15 bearing member 15i female screw 17 rotating lifting shaft 17a male screw 19 supporting member 20 upper valve body 20A upper valve closing spring (upper urging member)
20a Inner peripheral step 20b Stopper protrusion 20e Upper vertical passage (third embodiment)
23 Thrust Transmission Shaft 30 Upper Back Pressure Chamber 31 Upper Pressure Equalizing Passage 40 Mysterious Planetary Gear Type Reduction Mechanism 50 Stepping Motor (elevation drive)
55 stator 57 rotor 58 can 60 driven member 61 center hole 61a upper large-diameter fitting hole 61b lower large-diameter insertion hole 62 collar-shaped member 63 outer collar-shaped locking portion 65 connecting rod (connecting member)
66 through hole 67 communication hole 70 lower valve body 70A lower valve closing spring (lower urging member)
70a Central hole 70b Upper large-diameter insertion hole 70c Movable stopper protrusion (second embodiment)
70d lateral hole (second embodiment)
70e Lower longitudinal passage (third embodiment)
80 Lower back pressure chamber 81 Lower pressure equalizing passage

Claims (15)

A valve chamber, a first inlet/outlet opening to the valve chamber, a second inlet/outlet, and a third inlet/outlet, and an upper valve seat provided between the first inlet/outlet and the second inlet/outlet, and A valve body having a lower valve seat provided between the first inlet/outlet and the third inlet/outlet;
An upper valve body which is arranged in the valve chamber so as to be able to move up and down and is brought into contact with and separated from the upper valve seat;
A lower valve element that is arranged in the valve chamber so as to be able to move up and down, and is brought into contact with and separated from the lower valve seat;
An upper urging member for urging the upper valve body in the valve closing direction,
A lower urging member for urging the lower valve body in the valve closing direction,
Relative movement in the up-and-down direction relative to the upper valve body, and engageable with the upper valve body to separate the upper valve body from the upper valve seat against the urging force of the upper urging member A driven member disposed in
In order to separate the lower valve body from the lower valve seat against the biasing force of the lower biasing member, the driven member and the lower valve body can be integrally moved, and the driven member and the lower valve body. And a connecting member for connecting the and so as to be relatively movable in the vertical direction,
An elevating and lowering drive unit for elevating and lowering the driven member,
Depending on the lift amount of the driven member,
A state in which the lower valve body is pushed down from the lower valve seat by the connecting member while the upper valve body is seated on the upper valve seat,
A state in which the upper valve body is seated on the upper valve seat and the lower valve body is seated on the lower valve seat,
While the lower valve body is seated on the lower valve seat, a state in which the upper valve body is pulled up from the upper valve seat by the driven member can be selectively taken .
Until the lift amount of the driven member reaches a predetermined first lift amount, the upper member is kept seated on the upper valve seat by the urging force of the upper urging member, and the lower member is attached by the connecting member. The lower valve body is pushed down from the lower valve seat against the biasing force of the biasing member,
While the lift amount of the driven member exceeds the first lift amount and reaches a predetermined second lift amount, the upper valve body is seated on the upper valve seat by the urging force of the upper urging member, The lower valve body is seated on the lower valve seat by the urging force of the lower urging member,
When the lift amount of the driven member exceeds the second lift amount, the lower valve body is seated on the lower valve seat by the urging force of the lower urging member and the upper member is urged by the driven member. A three-way switching valve, wherein the upper valve body is pulled up from the upper valve seat against the urging force of the valve. The three-way switching valve according to claim 1 , wherein the connecting member is formed of a cylindrical member or a columnar member that extends in the vertical direction. An upper end of the connecting member is inserted into the driven member so as to be relatively movable in the up-and-down direction and engageable, and a lower end thereof is inserted in the lower valve body so as to be relatively movable in the up-and-down direction and engageable. The three-way switching valve according to claim 1 or 2 , characterized in that. The three-way switching valve according to any one of claims 1 to 3 , wherein the upper urging member is interposed between the upper valve body and the driven member. The three-way switching valve according to any one of claims 1 to 3 , wherein the upper urging member is interposed between the upper valve body and the valve body. The driven member is inserted into the upper valve body so as to be relatively movable in a vertical direction, and is engaged with the upper valve body according to a lift amount on the outer periphery of the lower end portion of the driven member to move the upper valve body. The three-way switching valve according to any one of claims 1 to 5 , further comprising an outer collar-shaped locking portion for pulling up from the upper valve seat. The three-way switching valve according to any one of claims 1 to 6 , wherein a stopper mechanism that regulates the downward movement of the driven member is configured by the driven member and the upper valve body. The three-way switching valve according to any one of claims 1 to 6 , wherein a stopper mechanism that regulates the downward movement of the driven member includes the lower valve body and the valve body. The chamber diameter of the upper back pressure chamber defined on the upper side of the upper valve body and the aperture of the upper valve seat are set to be the same, and an upper pressure equalizing passage that constantly connects the upper back pressure chamber and the valve chamber. And/or the diameter of the lower back pressure chamber defined below the lower valve body and the diameter of the lower valve seat are set to be the same, and the lower back pressure chamber and The three-way switching valve according to any one of claims 1 to 8 , further comprising a lower pressure equalizing passage that is in constant communication with the valve chamber. The upper pressure equalizing passage is configured to include a through hole provided in the connecting member, a communication hole that communicates the through hole with the valve chamber, and the inside of the driven member. The three-way switching valve according to claim 9 . The three-way switching valve according to claim 9 , wherein the upper pressure equalizing passage is constituted by an upper vertical through passage provided inside the upper valve body. The lower pressure equalizing passage is configured to include a through hole provided in the connecting member, a communication hole that communicates the through hole with the valve chamber, and the inside of the lower valve body. The three-way switching valve according to claim 9 . The three-way switching valve according to claim 9 , wherein the lower pressure equalizing passage is constituted by a lower vertical through passage provided inside the lower valve body. The lifting drive unit includes a stepping motor having a stator mounted on a can fixed to the valve body and a rotor rotatably disposed inside the can.
Through the screw feed mechanism provided between the driven member and the rotor, any one of claims 1 to 13, the driven member is equal to or adapted to be brought into the lift without rotating A three-way switching valve according to item. 15. The three-way switching valve according to claim 14 , wherein a planetary gear type speed reduction mechanism that reduces the speed of rotation of the rotor and transmits the rotation is interposed between the rotor and the screw feed mechanism.