JP6656938B2 - Flow path switching valve - Google Patents

Description

  The present invention relates to a flow path switching valve, and more particularly to a flow path switching valve such as an electric valve used in a heat pump type cooling and heating system.

  Conventionally, as a flow path switching valve of this type, a slide valve body is moved in a valve body of a refrigerant flow path switching six-way valve or an eight-way valve by a pilot solenoid valve using a solenoid coil, and provided on a valve seat. There is known a device that switches between a cooling operation (defrosting operation) and a heating operation by switching the communication state of ports, that is, the flow direction (flow path) of the refrigerant (for example, see Patent Document 1 below).

JP-A-8-170864

  By the way, in the above-mentioned conventional flow path switching valve, by controlling the energization state of the solenoid coil of the pilot solenoid valve, the introduction of high pressure into the pressure conversion chamber formed on both sides of the piston provided in the valve body is performed. The derivation is controlled, so that the slide valve body fixed to the piston is moved in the valve body. Therefore, it is necessary to separately prepare a pilot solenoid valve for driving the slide valve body at the time of switching the flow path, and there are problems that the configuration is complicated and that miniaturization is difficult. When an electromagnetic valve is used as a pilot valve, the opening area of both ports changes rapidly at the time of the switching, and the high-pressure refrigerant flows into the low-pressure port (conduit) at a stretch, and suddenly in the heat pump cooling and heating system. There is also a problem that a large pressure fluctuation occurs and a loud noise (switching sound) is generated.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to relatively efficiently switch a flow direction (flow path) of a fluid with a relatively simple configuration. An object of the present invention is to provide a flow path switching valve that can contribute to miniaturization, large capacity, power saving, and the like.

In order to solve the above-described problems, a flow path switching valve according to the present invention includes a tubular inner housing having a valve chamber, and an outer passage formed outside the inner housing so as to form a communication space outside the inner housing. An outer housing, a valve shaft disposed in the valve chamber so as to be able to move up and down, and at least two valve bodies inscribed in the inner housing and provided in the axial direction so as to be spaced apart from each other; An elevation drive unit for elevating and lowering the valve shaft in a room, wherein the inner housing has at least two inner ports opened to the valve chamber separated from each other in the axial direction, and the valve chamber the two communication port which always communicates the communicating space is made to open by axially spaced, on the outer housing, the outer port which always communicates with the communication space is made to open the A lower back pressure chamber which is defined below the said at least two valve body in the valve chamber and the upper back pressure chamber wherein is defined above the at least two valve body in said valve chamber, said valve The valve shaft is moved up and down in the valve chamber by the lift drive unit while the at least two valve bodies are in contact with the inner housing, and the valve shaft is constantly communicated through a communication passage provided in the shaft. The communication state between the at least two inner ports and the outer port is switched , and at a raised position and a lowered position of the valve shaft, one of the two communication ports is connected to the communication passage. to communicate with the other of said two communicating port is characterized Rukoto communicated to one of said at least two inner ports.

  In a preferred aspect, the communication space is formed on the outer periphery of the inner housing, or is formed on a part of the outer periphery of the inner housing.

In another preferred embodiment, the inner housings in g the outer peripheral D-cut surface is provided on the said communication space by the inner peripheral surface of said outer housing and said D-cut surface is formed.

  In another preferred embodiment, the at least two inner ports and the outer port are opened on opposite sides or the same side in the axial direction.

  In another preferred aspect, the communication port is located above the at least two inner ports and below the at least two inner ports, and is an uppermost valve element and a lowermost valve of the at least two valve elements. They can be opened at the same interval as the body.

  In another preferred embodiment, the outer port is opened to the communication space so as to always communicate with the communication space, or is opened at the same height as the communication port in the inner housing. The communication space is always communicated with the communication space via the opening.

  In another preferred aspect, the elevation drive section is configured by a stepping motor having a rotor integrally connected to the valve shaft and a stator for rotating the rotor.

  In another preferred embodiment, a seal member is mounted on the outer periphery of the at least two valve bodies, and a packing having a higher hardness than the seal member is mounted outside the seal member.

In another preferred aspect, a concave portion is provided at a portion of the inner periphery of the inner housing where the at least two inner ports and the two communication ports are formed.

  In a further preferred aspect, a tapered surface portion is provided on an upper surface and / or a lower surface of the concave surface portion.

  In another preferred aspect, the valve shaft includes a plurality of connecting shaft components each provided with one valve element.

  In another preferred aspect, a lid-like member having a stopper for restricting the lowering of the valve shaft is attached to the outer housing or the inner housing.

In a further preferred aspect, the lid-shaped member is configured to always communicate the upper back pressure chamber and the lower back pressure chamber when the valve shaft comes into contact with the stopper portion and is stopped. vertical hole and horizontal hole is provided which communicates with the communication passage provided in the valve shaft.

  According to the flow path switching valve of the present invention, the valve shaft is moved up and down in the valve chamber by the elevation drive unit in a state where at least two valve elements provided on the valve shaft are in contact with the inner housing. Since the communication state (flow direction) between at least two provided inner ports and the outer port provided in the outer housing is switched, the flow direction (flow path) of the fluid can be efficiently changed with a relatively simple configuration. Switching can be performed, and the upper back pressure chamber defined above the at least two valve bodies and the lower back pressure chamber defined below the at least two valve bodies are always in communication with each other. As a result, the load acting on the valve body at the time of switching the flow path can be reduced as much as possible, and the driving torque of the valve body can be reduced, thereby further reducing the size, increasing the capacity, and saving power. In That.

  Further, since the elevating drive unit for elevating the valve shaft is constituted by a stepping motor having a rotor integrally connected to the valve shaft and a stator for rotating the rotor, for example, it is excluded from the heating operation. When switching from the frost operation to the defrosting operation to the heating operation, the pressure difference between the high-pressure side and the low-pressure side can be reduced, so that there is also an effect that noise can be effectively reduced.

FIG. 2 is a longitudinal sectional view showing a first flow state (valve shaft: lowered position) of the first embodiment of the flow path switching valve according to the present invention. FIG. 2 is a longitudinal sectional view showing a second flow state (valve shaft: ascending position) of the flow path switching valve shown in FIG. 1. FIG. 2 is a perspective view showing a lid member of the flow path switching valve shown in FIG. 1. The longitudinal section showing the 1st flow state (valve shaft: descent position) of a 2nd embodiment of the passage change valve concerning the present invention. FIG. 5 is a longitudinal sectional view showing a second flow state (valve element: ascending position) of the flow path switching valve shown in FIG. 4. FIG. 5 is a longitudinal sectional view showing a modified example (No. 1) of the flow path switching valve of the second embodiment shown in FIG. 4. (A) is a longitudinal cross-sectional view showing a modification (No. 2) of the flow path switching valve of the second embodiment shown in FIG. 4, and (B) is a cross-sectional view taken along the line U-U of (A). The longitudinal section showing the 1st flow state (valve shaft: descent position) of a 3rd embodiment of a flow-path switching valve concerning the present invention. FIG. 9 is a longitudinal sectional view showing a second flow state (valve shaft: ascending position) of the flow path switching valve shown in FIG. 8. FIG. 9 is a sectional view taken along the line VV in FIG. The longitudinal section showing the 1st flow state (valve shaft: descent position) of a 4th embodiment of a flow-path switching valve concerning the present invention. FIG. 12 is a longitudinal sectional view showing a second flow state (valve shaft: ascending position) of the flow path switching valve shown in FIG. 11. FIG. 13 is a longitudinal sectional view showing a first flow state (valve shaft: lowered position) of a fifth embodiment of the flow path switching valve according to the present invention. FIG. 14 is a longitudinal sectional view showing a second flow state (valve shaft: ascending position) of the flow path switching valve shown in FIG. 13. FIG. 14 is an enlarged view of a main part, in which a state in which a valve element in the flow path switching valve shown in FIG. 13 passes over the inside port at the time of flow path switching is enlarged. FIG. 16 is a longitudinal sectional view showing a first flow state (valve shaft: lowered position) of a sixth embodiment of the flow path switching valve according to the present invention. FIG. 17 is a longitudinal sectional view showing a second flow state (valve shaft: ascending position) of the flow path switching valve shown in FIG. 16.

  Hereinafter, embodiments of a flow path switching valve according to the present invention will be described with reference to the drawings.

[First Embodiment]
1 and 2 are longitudinal sectional views showing a first embodiment of a flow path switching valve according to the present invention. FIG. 1 shows a first flow state (valve shaft: lowered position), and FIG. The flow state (valve shaft: ascending position) is shown.

  In the present specification, descriptions indicating positions and directions such as up and down, left and right, front and back, etc. are given for convenience according to the drawings in order to avoid complicating the description, and the positions and directions in an actual use state are described. Does not always mean

  In each of the drawings, a gap formed between members, a separation distance between members, and the like are larger than dimensions of each constituent member for easy understanding of the invention and for convenience of drawing. Or it may be drawn small.

  The flow path switching valve 1 of the present embodiment is, for example, an electrically operated multi-way switching valve (in the first embodiment, a four-way switching valve) that switches a flow direction (flow path) of a fluid (refrigerant) in a heat pump type cooling / heating system or the like. ).

  The flow path switching valve 1 of the illustrated embodiment mainly includes a valve body 10 having an outer housing 9 and an inner housing 9A made of a sheet metal tubular base (having a constant inner diameter) arranged coaxially. The fixed can 58, a support member 19 fixed to the valve body 10 in an internal space defined by the valve body 10 and the can 58, and a support member 19 supported to be movable up and down in the internal space. Shaft 20 having a valve body (a first valve body 21, a second valve body 22, and a third valve body 23 from above), and a stepping motor mounted above the valve body 10 to move the valve shaft 20 up and down. (Elevation drive unit) 50.

  At the lower opening of the outer housing 9 of the valve body 10, for example, a metal lid-like member 11 is hermetically attached by welding, caulking, brazing, or the like. In detail, the lid-like member 11 has a stepped short columnar shape, as can be clearly understood from FIG. 3 in combination with FIGS. It has a diameter fitting portion 11b and a small diameter projecting portion 11a. The lid-shaped member 11 is in a state where the middle diameter fitting portion 11b is airtightly fitted to the lower opening of the inner housing 9A (in other words, the lower opening of the inner housing 9A is airtightly fitted to the middle diameter fitting portion 11b). The lower end of the outer housing 9 is joined by welding or the like to a flange portion 11d provided at the lower end of the outer periphery of the large-diameter joint portion 11c, and a cylindrical space is formed inside the inner housing 9A. , And a cylindrical communication space 8 is defined between the inner housing 9A and the outer housing 9. The small-diameter projecting portion 11a has a central portion communicating with a through-hole 29a of a connecting shaft 29 of the valve shaft 20 (when the valve shaft 20 is at the lowered position) and a little more than the through-hole 29a. A large-diameter vertical hole 11v is formed, and a plurality of (four in the illustrated example, four at 90 ° angular intervals) horizontal holes 11u are formed on the side. Further, here, the upper end of the small-diameter projecting portion 11a abuts against the third valve body 23 to limit the downward movement (downward movement) of the valve shaft 20 when switching the flow path (in other words, the lowering position of the valve shaft 20). Is defined as a stopper portion 11s.

  The inner housing 9 </ b> A disposed inside the outer housing 9 is formed to be slightly thicker than the outer housing 9. Near the center of the side, three inner housings are arranged in the direction of the axis O (vertical direction). The ports p1, p2, and p3 are opened, and a communication port p11 that communicates the valve chamber 7 with the communication space 8 is opened above the upper inside port p1, and below the lower inside port p3. A communication port p12 for communicating the valve chamber 7 with the communication space 8 is opened. More specifically, the communication port p11 is located above the first valve body 21 when the valve shaft 20 is at the lowered position and below the first valve body 21 when the valve shaft 20 is at the raised position. And the communication port p12 is located above the third valve body 23 when the valve shaft 20 is at the lowered position and below the third valve body 23 when the valve shaft 20 is at the raised position. As well as being formed, the communication port p11 and the communication port p12 are opened at the same interval as the interval between the first valve body 21 and the third valve body 23 (details will be described later).

  In the vicinity of the center of the side of the outer housing 9, a laterally outward port p10 opening to the communication space 8 is formed, and the outer port p10 is always in communication with the communication space 8.

  In the present example, when viewed in a plan view (that is, in the direction of the axis O), three inner ports p1, p2, and p3 provided apart from each other in the direction of the axis O are formed at the same position, and two communication ports are formed. The ports p11 and p12 are formed at the same position, and are formed on the opposite sides (at 180 ° angular intervals) of the three inner ports p1, p2 and p3 and the two communication ports p11 and p12. The outer port p10 is formed on the opposite side (in other words, the same side as the two communication ports p11 and p12) of the inner ports p1, p2 and p3 when viewed in a plan view.

  Conduit fittings # 1, # 2, # 3 are attached to the three inner ports p1, p2, p3 sideways (through the outer housing 9) by brazing or the like, and the outer port p10 is The conduit joint # 10 is mounted horizontally by brazing or the like.

  A stepped cylindrical base 13 is attached to an upper opening of the outer housing 9 of the valve body 10, and a lower surface of the cylindrical base 13 forms a ceiling surface of the communication space 8. The lower end of a cylindrical can 58 with a ceiling is joined to the upper end of the cylindrical base 13 by welding or the like.

  The support member 19 has a cylindrical holding member 14 with a bottom wall 14c and a bearing member 15 with a female screw 15i. The cylindrical holding member 14 is fixed to the inside of the cylindrical base 13 by press fitting or the like. On the upper part of the member 14, a cylindrical bearing member 15 in which a female screw 15i is screwed in the lower half of the inner circumference is fixed by caulking or the like. The bottom wall 14c of the cylindrical holding member 14 is airtightly fitted (internally fitted) to the upper opening of the inner housing 9A, and a cylindrical lifting spring receiver 28 described later is slidably inserted therein. A cylindrical fitting portion 14b is provided to project downward. The outer periphery of the bearing member 15 is formed with a step, and a spring chamber 14a is defined between the cylindrical holding member 14 and the bearing member 15, and the valve shaft 20 is attached to the spring chamber 14a upward. The biasing compression coil spring 25 is housed. An upper portion of the inner periphery of the bearing member 15 above the female screw 15i is a fitting hole 15a into which a lower base portion of an output shaft 46 of the reduction mechanism 40 described later is fitted.

  On the other hand, the stepping motor 50 is provided with a stator 55 including a yoke 51, a bobbin 52, a coil 53, a resin mold cover 54, and the like, and is rotatably disposed inside the can 58 with respect to the can 58. And a rotor 57 fixed to the upper inside. The stator 55 is externally fixed to the can 58. On the inner peripheral side of the rotor 57, a sun gear 41 formed integrally with the rotor support member 56, and a fixed ring gear 47 fixed to the upper end of the cylindrical body 43 fixed on the upper part of the cylindrical holding member 14. A planetary gear 42 disposed 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 outside. And a mysterious planetary gear type speed reduction mechanism 40 including an output shaft 46 and the like in which an upper fitting portion is fixed by press-fitting or the like in a hole formed in the bottom of the output gear 45. 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 at the center of the upper fitting portion of the output shaft 46, and the lower portion of the support shaft 49 that passes through the center of the sun gear 41 (the rotor support member 56) and the carrier 44 is inserted into 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 the support member 48 that is disposed above the rotor support member 56 and inscribed in the can 58. 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 externally fitted and fixed to the can 58 is always kept constant.

  The lower base portion of the output shaft 46 of the speed reduction mechanism 40 is rotatably fitted into a fitting hole 15a formed in the upper portion of the bearing member 15 with the female screw 15i. A vertically elongated slit-like fitting portion 46a extending in the lateral direction so as to pass therethrough is formed. A plate-like portion 17c is projected from the upper end of the rotary elevating shaft 17 on which a male screw 17a screwed with a female screw 15i screwed on the inner periphery of the bearing member 15 is provided, and the plate-like portion 17c has a vertically long slit shape. It is slidably fitted to the fitting portion 46a. 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 rotation elevating shaft 17, and the rotation of the rotation elevating shaft 17 is performed by the screw feed of the female screw 15 i of the bearing member 15 and the male screw 17 a of the rotation elevating shaft 17. Goes up and down while rotating.

  Below the rotary elevating shaft 17, a valve shaft 20 through which the thrust downward of the rotary elevating shaft 17 is transmitted via the ball 18 and the ball seat 16 is arranged along the axis O (elevating direction). .

  Here, as described above, the compression coil spring 25 housed in the spring chamber 14a above the bottom wall 14c of the cylindrical holding member 14 is arranged with its lower end in contact with the bottom wall 14c. In order to transmit the urging force (pulling force) of the compression coil spring 25 to the valve shaft 20, a cylindrical pulling spring receiver 28 having upper and lower flange-shaped hooks is provided. The lifting spring receiving body 28 is slidably fitted on the bearing member 15 (the lower small-diameter portion of the bearing member 15) and slides on the cylindrical fitting portion 14 b extending downward from the bottom wall 14 c of the cylindrical holding member 14. The upper hook portion is mounted on the upper portion of the compression coil spring 25, and the lower hook portion is hooked on (the lower step surface of the large-diameter upper portion 27a of the thrust transmission shaft 27). Is stopped. In other words, the lifting spring receiving body 28 moves in the axis O direction (elevation direction) while being guided by (the lower small-diameter portion of) the bearing member 15 and the cylindrical fitting portion 14 b of the cylindrical holding member 14. The cylindrical holding member 14 is provided with a communication hole 14d for communicating the spring chamber 14a with the inside of the can 58.

  The valve shaft 20 basically includes a stepped cylindrical thrust transmission shaft 27 connected to the rotary elevating shaft 17 via the ball 18 and the ball seat 16, and (a small-diameter lower portion 27 c of) the thrust transmission shaft 27. And a cylindrical connecting shaft 29 made of synthetic resin and connected to the connecting shaft 29. The connecting shaft 29 is provided with three short cylindrical valve bodies (a first valve body 21 and a second valve body) spaced apart in the direction of the axis O. The body 22, the third valve body 23) are integrally formed.

  The thrust transmitting shaft 27 includes, from the upper side, a large-diameter upper portion 27a into which the ball seat 16 is fitted on the inner periphery, an intermediate body portion 27b inserted through a hook formed below the lifting spring receiver 28, and a connecting shaft. 29 is constituted by a small-diameter lower portion 27c having a diameter smaller than that of the intermediate body portion 27b which is fitted into a through hole 29a provided in the center of the axis 29 (along the axis O) and fixed by press-fitting, brazing, or the like. A vertical through-hole 27d forming the upper part of the communication passage 32 provided in the valve shaft 20 and a plurality of horizontal holes 27e opening to the upper back pressure chamber 30 described later are formed. The upper end opening of the through hole 27d is closed by the ball seat 16.

  The connection shaft 29 is disposed along the longitudinal direction (the direction of the axis O), and each valve body (the first valve body 21, the second valve body 22, and the third valve body 23) is provided with an inner diameter of the inner housing 9A. Of the three inner ports p1 to p3 opened in the inner housing 9A, between adjacent ports p1 and p2, and between p2 and p3. The connection shaft 29 is disposed so as to define a space having a size that can be obtained. Further, as described above, the first valve element 21 is located below the communication port p11 when the valve shaft 20 is at the lowered position and above the communication port p11 when the valve shaft 20 is at the raised position. The third valve element 23 is located below the communication port p12 when the valve shaft 20 is in the lowered position and above the communication port p12 when the valve shaft 20 is in the raised position. It is arranged on the connecting shaft 29 so that

  In this example, the first valve element 21 is formed at the upper end of the connection shaft 29, the third valve element 23 is formed at the lower end thereof, and the second valve element 22 is formed at the upper and lower center of the first shaft 21. The space formed between 21 and the second valve body 22 and the space formed between the second valve body 22 and the second valve body 23 are designed to be substantially the same.

  The annular groove formed on the outer periphery of each valve element (first valve element 21, second valve element 22, third valve element 23) has a sliding surface gap between each valve element and inner housing 9A. Sealing members 21A, 22A, 23A such as O-rings are attached to seal the outer peripheral portions of the seal members 21A, 22A, 23A to reduce the sliding resistance of each valve body with respect to the inner housing 9A. Are mounted with ring-shaped packings (also referred to as cap seals) 21B, 22B and 23B made of PTFE (Teflon (registered trademark)) or the like.

  The horizontal hole 27e and the through hole 27d of the thrust transmission shaft 27 and the through hole 29a of the connecting shaft 29 balance the pushing force acting on the valve shaft 20 and the pushing force acting on the valve shaft 20 (cancel the differential pressure). The upper back pressure chamber 30 defined above the first valve body 21 in the valve chamber 7 and the lower back pressure chamber 31 defined below the third valve body 23 in the valve chamber 7 A communication path 32 that is always in communication is configured.

  When the rotor 57 of the stepping motor 50 is rotationally driven in the flow path switching valve 1 having such a configuration, the rotary elevating shaft 17 moves up and down while rotating, but the ball 18 is interposed between the rotary elevating shaft 17 and the valve shaft 20. By doing so, only the downward thrust is transmitted from the rotary elevating shaft 17 to the valve shaft 20 (no rotational force is transmitted), and the rotary elevating shaft 17 and the valve shaft 20 are integrally moved up and down in the direction of the axis O. . Here, each valve element (first valve element 21, second valve element 22, third valve element 23) provided on the valve shaft 20 is brought into contact with (the inner periphery of) the inner housing 9A, The valve shaft 20 moves up and down in the valve chamber 7 in a state where each valve element (the first valve element 21, the second valve element 22, and the third valve element 23) is inscribed in the inner housing 9A. The communication state (flow direction, flow path) between the inner ports p1, p2, p3 and the outer port p10 is switched.

  That is, when the rotor 57 of the stepping motor 50 is driven to rotate in one direction, the rotation of the rotor 57 is reduced and transmitted to the rotary elevating shaft 17 via the output shaft 46 of the reduction mechanism 40, and the female screw 15 i of the bearing member 15 is For example, the rotary elevating shaft 17 is lowered while rotating by the screw feed of the rotary elevating shaft 17 by the male screw 17 a, and the valve shaft 20 is pushed down by the thrust of the rotary elevating shaft 17 against the urging force of the compression coil spring 25, and the lowered position. (Here, the position provided at the lower end portion of the valve shaft 20 and at which the third valve body 23 comes into contact with the stopper portion 11s of the lid-like member 11 and is stopped) is taken. In this lowered position, the first valve body 21 is located between the communication port p11 and the inside port p1, the second valve body 22 is located between the inside port p2 and the inside port p3, and the third valve body 23 Is located below the communication port p12, the space between the first valve body 21 and the second valve body 22 is located right beside the inner port p1 and the inner port p2, and the second valve body 22 and the third Since the space between the valve bodies 23 is located between the inside port p3 and the communication port p12, the inside port p1 and the inside port p2 pass through the space between the first valve body 21 and the second valve body 22. The inside port p3 and the outside port p10 communicate with each other through the space between the second valve body 22 and the third valve body 23, the communication port p12, and the communication space 8 (the first flow state shown in FIG. 1). ).

  On the other hand, when the rotor 57 of the stepping motor 50 is driven to rotate in the other direction, the rotation of the rotor 57 is reduced and transmitted to the rotating shaft 17 via the output shaft 46 of the reduction mechanism 40, and the female screw 15i and the male screw 17a are transmitted. For example, the rotary elevating shaft 17 is raised while being rotated by the screw feed, and accordingly the valve shaft 20 is pulled up by the urging force of the compression coil spring 25 to take the raised position. In this raised position, the first valve element 21 is located above the communication port p11, the second valve element 22 is located between the inner port p1 and the inner port p2, and the third valve element 23 is connected to the inner port p3. The space located between the communication port p12 and the first valve body 21 and the second valve body 22 is located between the communication port p11 and the inner port p1, and the second valve body 22 and the third valve body 23 is located right beside the inner port p2 and the inner port p3, so that the inner port p2 and the inner port p3 communicate with each other via the space between the second valve body 22 and the third valve body 23. Then, the inside port p1 and the outside port p10 communicate with each other via the space between the first valve body 21 and the second valve body 22, the communication port p11, and the communication space 8 (the second flow state shown in FIG. 2).

  Here, in the present embodiment, the upper back pressure chamber 30 (the upper part of the valve chamber 7) defined above the first valve body 21 and the third back pressure chamber 30 via the communication passage 32 provided in the valve shaft 20. The lower back pressure chamber 31 (the lower part of the valve chamber 7) defined below the valve body 23 is always in communication. That is, the upper surface of the first valve body 21 (the surface on the side of the upper back pressure chamber 30) and the lower surface of the third valve body 23 (the surface on the side of the lower back pressure chamber 31) are pressure-equalized. The surfaces of the body (the first valve body 21, the second valve body 22, and the third valve body 23) that face each other in the vertical direction are also equalized. Therefore, when the flow path is switched by the movement of the valve body (the first valve body 21, the second valve body 22, the third valve body 23) in the direction of the axis O, the valve body moves in the moving direction (the direction of the axis O of the valve shaft 20). The acting force (the pushing force and the pushing force acting on the valve element) can be balanced (all the differential pressure is canceled).

  As described above, in the present embodiment, the state in which the three valve elements (the first valve element 21, the second valve element 22, and the third valve element 23) provided on the valve shaft 20 are inscribed in the inner housing 9A. By controlling the stepping motor 50 to raise and lower the valve shaft 20 in the valve chamber 7, the three inner ports p1, p2, p3 provided in the inner housing 9A and the outer port p10 provided in the outer housing 9 are controlled. Since the communication state (flow direction) between them can be switched, the flow direction (flow path) of the fluid can be efficiently switched with a relatively simple configuration, and the uppermost one of the three valve bodies can be switched. Since the upper back pressure chamber 30 above the one valve body 21 and the lower back pressure chamber 31 below the lowermost third valve body 23 are always in communication, the upper back pressure chamber 30 is connected to the valve body when the flow path is switched. Acting load as small as possible Comb, can reduce driving torque of the valve body, has been, further miniaturization, larger capacity, it is also possible to achieve power saving or the like.

  In the present embodiment, the sliding resistance of each valve body with respect to the inner housing 9A is reduced outside the seal members 21A, 22A, and 23A provided on the outer periphery of each valve body (the sliding surface with the inner housing 9A). In addition, in order to suppress the elastic deformation of the seal members 21A, 22A, and 23A (particularly, the elastic deformation that occurs when the seal members 21A, 22A, and 23A pass over the inner ports and the communication ports at the time of switching the flow path is suppressed. In addition, packings 21B, 22B made of PTFE (Teflon (registered trademark)) or the like having relatively high hardness are used to reduce the resistance when the seal members 21A, 22A, 23A pass over the inner ports and the communication ports. , 23B are mounted, the load acting on the valve body at the time of switching the flow path can be reduced as much as possible, and the driving torque of the valve body can be reduced more effectively. Can be reduced.

  Further, in the present embodiment, since the stepping motor 50 is controlled to gradually raise and lower the valve shaft 20 in the valve chamber 7, for example, the heating operation is changed to the defrosting operation and the defrosting operation is changed to the heating operation. When switching to operation, the pressure difference between the high-pressure side and the low-pressure side can be reduced, so that there is also an effect that noise can be effectively reduced.

[Second embodiment]
4 and 5 are longitudinal sectional views showing a second embodiment of the flow path switching valve according to the present invention. FIG. 4 shows a first flow state (valve shaft: lowered position), and FIG. The flow state (valve shaft: ascending position) is shown.

  The flow path switching valve 2 of the second embodiment is basically different from the flow path switching valve 1 of the first embodiment in the number of inner ports formed in the inner housing and the number of valve bodies formed in the valve shaft. Only the differences. Therefore, components having the same functions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Only the differences described above will be described in detail below.

  The flow path switching valve 2 of the present embodiment is used as a six-way switching valve in, for example, a heat pump type cooling / heating system or the like, and has five inner side housings 9A arranged side by side in the axis O direction (vertical direction). The inner ports p1, p2, p3, p4, and p5 are opened, and a communication port p11 that communicates the valve chamber 7 with the communication space 8 is opened above the upper inner port p1, and the lower inner port p5 is opened. A communication port p12 that communicates the valve chamber 7 with the communication space 8 is opened further below. In addition, conduit fittings # 1, # 2, # 3, # 4, and # 5 are respectively connected to the inner ports p1, p2, p3, p4, and p5 (through the outer housing 9) by brazing or the like. Mounted sideways.

  The connecting shaft 29 constituting the valve shaft 20 is provided with four short columnar valve bodies (a first valve body 21, a second valve body 22, a third valve body 23, a fourth valve body 23) spaced apart in the direction of the axis O. The valve body 24) is formed integrally. In this example, the first valve body 21 is formed at the upper end of the connecting shaft 29, and the fourth valve body 24 is formed at the lower end thereof, and each of the valve bodies (the first valve body 21, the second valve body 22, The third valve body 23 and the fourth valve body 24) are disposed at substantially equal intervals in the direction of the axis O. Also in this example, the annular groove formed on the outer periphery of each valve element (the first valve element 21, the second valve element 22, the third valve element 23, and the fourth valve element 24) has a seal such as an O-ring. The members 21A, 22A, 23A, and 24A are mounted, and a ring-shaped packing (also referred to as a cap seal) made of PTFE (Teflon (registered trademark)) or the like is provided outside each of the sealing members 21A, 22A, 23A, and 24A. ) 21B, 22B, 23B and 24B are mounted.

  Even in the flow path switching valve 2 having such a configuration, when the rotor 57 of the stepping motor 50 is rotationally driven, each of the valve bodies (the first valve body 21, the second valve body 22, the third valve body 23, and the fourth valve body 24). The valve shaft 20 is moved up and down in the valve chamber 7 in a state where the valve shaft is inscribed in the inner housing 9A, whereby a communication state (flow) between the five inner ports p1, p2, p3, p4, p5 and the outer port p10 is established. Direction and flow path) are switched.

  That is, when the rotor 57 of the stepping motor 50 is driven to rotate in one direction, the valve shaft 20 is moved to the lowered position (here, the fourth valve body 24 is provided at the lower end of the valve shaft 20), as in the first embodiment. In this lowered position, the first valve body 21 is located between the communication port p11 and the inner port p1, and the second valve The body 22 is located between the inside port p2 and the inside port p3, the third valve body 23 is located between the inside port p4 and the inside port p5, and the fourth valve body 24 is located below the communication port p12. The space between the first valve body 21 and the second valve body 22 is located right beside the inner port p1 and the inner port p2, and the space between the second valve body 22 and the third valve body 23 is , Located right beside the inner port p3 and the inner port p4, The space between the valve element 23 and the fourth valve element 24, is caused to position between the inner port p5 and the communication port p12. Thus, the inner port p1 and the inner port p2 communicate with each other via the space between the first valve body 21 and the second valve body 22, and the inner port p3 and the inner port p4 connect the second valve body 22 and the third The inside port p5 and the outside port p10 communicate through a space between the valve bodies 23, and the inside port p5 and the outside port p10 communicate through a space between the third valve body 23 and the fourth valve body 24, the communication port p12, and the communication space 8. (First flow state shown in FIG. 4).

  On the other hand, when the rotor 57 of the stepping motor 50 is driven to rotate in the other direction, the valve shaft 20 assumes the ascending position, as in the first embodiment. At this ascending position, the first valve element 21 is connected to the communication port p11. , The second valve element 22 is located between the inner port p1 and the inner port p2, the third valve element 23 is located between the inner port p3 and the inner port p4, and the fourth valve element 24 is located between the inside port p5 and the communication port p12, the space between the first valve body 21 and the second valve body 22 is located between the communication port p11 and the inside port p1, and the second valve body The space between the second valve body 22 and the third valve body 23 is located right beside the inside port p2 and the inside port p3, and the space between the third valve body 23 and the fourth valve body 24 is the inside port p4 and the inside port p5. It is located right beside. As a result, the inner port p2 and the inner port p3 communicate with each other via the space between the second valve body 22 and the third valve body 23, and the inner port p4 and the inner port p5 connect the third valve body 23 and the fourth port The inside port p1 and the outside port p10 communicate with each other via the space between the valve bodies 24, and communicate with each other via the space between the first valve body 21 and the second valve body 22, the communication port p11, and the communication space 8. (2nd flow state shown in FIG. 5).

  Here, also in the present embodiment, the lower side of the upper back pressure chamber 30 defined above the first valve body 21 and the lower side of the fourth valve body 24 via the communication passage 32 provided in the valve shaft 20. And the lower back pressure chamber 31 defined at the same time, the same operation and effect as the first embodiment can be obtained.

  In this example, the outer port p10 is formed on the opposite side of the inner ports p1, p2, p3, p4, and p5 when viewed in a plan view (in other words, on the same side as the two communication ports p11 and p12). However, it goes without saying that the positions of the outer port p10, the inner ports p1 to p5, and the communication ports p11 and p12 can be appropriately changed according to the application location of the flow path switching valve 2 and the like. For example, as shown in FIG. 6, the outer port p10 and the inner ports p1 to p5 may be formed on the same side when viewed in plan. In the example shown in FIG. 6, the outer port p10 is formed above the inner ports p1 to p5. However, the outer port p10 may be formed below the inner ports p1 to p5. .

  Further, in this example, a cylindrical communication space 8 is provided between the inner housing 9A and the outer housing 9 (the outer periphery of the inner housing 9A) by the outer housing 9 and the inner housing 9A made of a cylindrical base arranged coaxially. 7A and 7B, for example, as shown in FIGS. 7A and 7B, the outer periphery of the inner housing 9A (specifically, a position covering the communication ports p11 and p12 formed in the inner housing 9A). Is connected (by welding, brazing, or the like) to the outer housing 9 and an inner housing 9A formed of a cylindrical base (the outer periphery of the inner housing 9A). (Partially), a substantially straight communication space 8 may be formed. In this case, in the example shown in FIGS. 7A and 7B, the lower end of the inner housing 9A is formed between the large-diameter joint portion 11c and the medium-diameter fitting portion 11b of the lid-like member 11. A stepped cylindrical base 13 is attached to the stepped portion by welding or the like, and an enlarged diameter portion 9B is provided at the upper end of the inner housing 9A.

[Third embodiment]
8 and 9 are longitudinal sectional views showing a third embodiment of the flow path switching valve according to the present invention. FIG. 8 shows a first flow state (valve shaft: lowered position), and FIG. The flow state (valve shaft: ascending position) is shown.

  The flow path switching valve 3 of the third embodiment is basically different from the flow path switching valve 2 of the second embodiment in the shape of the opening position of the outer port and the shape of the communication space between the outer housing and the inner housing. Are different. Therefore, components having the same functions as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Only the differences described above will be described in detail below.

  The flow path switching valve 3 of the present embodiment is used as a six-way switching valve in, for example, a heat pump cooling / heating system or the like as in the second embodiment, and the outer diameter of the inner housing 9A is equal to the inner diameter of the outer housing 9. The inner housing 9A is formed substantially in the same manner, the inner housing 9A is fitted into the outer housing 9, and the outer periphery of the inner housing 9A (specifically, a portion where the communication ports p11 and p12 are formed) has D (up and down). A cut surface 9C is formed, and the communication space 8 is formed by the D cut surface 9C and the inner peripheral surface of the outer housing 9 (see also FIG. 10).

  In this example, a sealing member 14A made of an O-ring or the like is interposed between the upper opening of the inner housing 9A and the cylindrical fitting portion 14b provided on (the bottom wall 14c of) the cylindrical holding member 14. Is equipped.

  The outer port p10 is formed on the upper side of the inner ports p1 to p5 in the outer housing 9 and at substantially the same height as the communication port p11, and is provided in the inner housing 9A so as to be connected to the outer port p10. It is always in communication with the communication space 8 through the opening p10a and the communication port p11.

  Even in the flow path switching valve 3 having such a configuration, when the rotor 57 of the stepping motor 50 is rotationally driven, each of the valve bodies (the first valve body 21, the second valve body 22, the third valve body 23, and the fourth valve body 24) is provided. The valve shaft 20 is moved up and down in the valve chamber 7 in a state where the valve shaft is inscribed in the inner housing 9A, whereby a communication state (flow) between the five inner ports p1, p2, p3, p4, p5 and the outer port p10 is established. Direction and flow path) are switched.

  That is, when the rotor 57 of the stepping motor 50 is driven to rotate in one direction, the valve shaft 20 is moved to the lowered position (here, the fourth valve body 24 is provided at the lower end of the valve shaft 20), as in the second embodiment. In this lowered position, the first valve body 21 is connected between the opening p10a communicating with the communication port p11 and the outer port p10 and the inner port p1. The second valve body 22 is located between the inside port p2 and the inside port p3, the third valve body 23 is located between the inside port p4 and the inside port p5, and the fourth valve body 24 Is located below the communication port p12, the space between the first valve body 21 and the second valve body 22 is located right beside the inner port p1 and the inner port p2, and the second valve body 22 and the third The space between the valve bodies 23 is Located just beside the p3 and inner port p4, the space between the third valve body 23 of the fourth valve element 24, is caused to position between the inner port p5 and the communication port p12. Thus, the inner port p1 and the inner port p2 communicate with each other via the space between the first valve body 21 and the second valve body 22, and the inner port p3 and the inner port p4 connect the second valve body 22 and the third The inner port p5 and the outer port p10 communicate with each other via the space between the valve bodies 23, and the space between the third valve body 23 and the fourth valve body 24, the communication port p12, the communication space 8, the communication port p12, The upper back pressure chamber 30 above the first valve body 21 communicates with the upper back pressure chamber 30 via the opening p10a (first flow state shown in FIG. 8).

  On the other hand, when the rotor 57 of the stepping motor 50 is driven to rotate in the other direction, the valve shaft 20 assumes the ascending position, as in the second embodiment. At this ascending position, the first valve element 21 is connected to the communication port p11. And the upper side of the opening p10a connected to the outer port p10, the second valve body 22 is positioned between the inner port p1 and the inner port p2, and the third valve body 23 is positioned between the inner port p3 and the inner port p4. , The fourth valve element 24 is positioned between the inner port p5 and the communication port p12, and the space between the first valve element 21 and the second valve element 22 is defined by the communication port p11 and the opening p10a and the inner port. The space between the second valve body 22 and the third valve body 23 is located between p1 and the inner port p2 and the inner port p3, and between the third valve body 23 and the fourth valve body 24. Space is inside port p4 and inside It is caused to position just beside the over door p5. As a result, the inner port p2 and the inner port p3 communicate with each other via the space between the second valve body 22 and the third valve body 23, and the inner port p4 and the inner port p5 connect the third valve body 23 and the fourth port The inner port p1 and the outer port p10 communicate via a space between the valve bodies 24, and communicate via a space between the first valve body 21 and the second valve body 22 (the second flow shown in FIG. 9). Status).

  Here, also in the present embodiment, the lower side of the upper back pressure chamber 30 defined above the first valve body 21 and the lower side of the fourth valve body 24 via the communication passage 32 provided in the valve shaft 20. And the lower back pressure chamber 31 defined at the same time, the same operation and effect as those of the first and second embodiments can be obtained.

  In this example, the outer port p10 is formed above the inner ports p1 to p5 in the outer housing 9 and at substantially the same height as the communication port p11. It is needless to say that it may be formed below the inside ports p1 to p5 and at substantially the same height as the communication port p12 so as to always communicate with the communication space 8 via the communication port p12.

[Fourth embodiment]
11 and 12 are longitudinal sectional views showing a fourth embodiment of the flow path switching valve according to the present invention. FIG. 11 shows a first flow state (valve shaft: lowered position), and FIG. The flow state (valve shaft: ascending position) is shown.

  The flow path switching valve 4 of the fourth embodiment is basically a communication path that always connects the upper back pressure chamber 30 and the lower back pressure chamber 31 to the flow path switching valve 2 of the second embodiment. 32 are different. Therefore, components having the same functions as those in the second embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Only the differences described above will be described in detail below.

  The flow path switching valve 4 of the present embodiment is used as a six-way switching valve in, for example, a heat pump type cooling / heating system or the like as in the above-described second embodiment. A small-diameter lower portion 27c of a stepped cylindrical thrust transmitting shaft 27 is fitted into a substantially solid central hole 29b formed at an upper end portion of the connecting shaft 29, and is connected by press fitting, brazing, or the like.

  The cylindrical fitting portion 14b provided on (the bottom wall 14c of) the cylindrical holding member 14 is formed to be slightly longer, and the cylindrical fitting portion 14b is formed so as to have a gap between the bottom wall 14c and the upper end of the inner housing 9A. The fitting portion 14b is fitted (inner fitting) into the upper opening of the inner housing 9A, and the upper portion of the tubular fitting portion 14b (specifically, corresponding to the gap in the tubular fitting portion 14b). (A portion) is formed with a lateral hole 32a. The horizontal hole 32a may be formed above the communication port p11 in the inner housing 9A and above the first valve body 21 when the valve shaft 20 is at the raised position.

  Further, a lateral hole 32b is formed below the communication port p12 in the inner housing 9A and on the side of the small-diameter projecting portion 11a of the lid-like member 11 (that is, a portion corresponding to the lower back pressure chamber 31). I have.

  Accordingly, in the flow path switching valve 4 of the present embodiment, the horizontal hole 32a of the cylindrical fitting portion 14b of the cylindrical holding member 14, the upper end of the inner housing 9A and the bottom wall 14c of the cylindrical holding member 14 are provided. The upper back pressure chamber 30 and the lower back pressure chamber 30 are formed by the communication space 8 between the inner housing 9A and the outer housing 9 (in other words, the outside of the inner housing 9A) including the gap formed in the inner housing 9A and the lateral hole 32b of the inner housing 9A. A communication passage 32 that constantly communicates with the side back pressure chamber 31 is formed.

  Even in the flow path switching valve 4 having such a configuration, when the rotor 57 of the stepping motor 50 is rotationally driven, each of the valve bodies (the first valve body 21, the second valve body 22, the third valve body 23, and the fourth valve body 24). The valve shaft 20 is moved up and down in the valve chamber 7 in a state in which the inner shaft is in contact with the inner housing 9A, so that the five inner ports p1, p2, p3, p4, p5 and The communication state (flow direction, flow path) between the outer port p10 is switched, but the communication port 32 including the communication space 8 between the inner housing 9A and the outer housing 9 is connected to the upper side of the first valve body 21. The lower back pressure chamber 31 defined below the fourth valve body 24 is always in communication with the upper back pressure chamber 30 defined in the first, second, and third embodiments. The same operation and effect as in the embodiment can be obtained.

  Further, in the present embodiment, since the through-hole in the connecting shaft 29 constituting the valve shaft 20 can be omitted, there is also an effect that the valve shaft 20 itself can have a relatively simple configuration.

  In this case, since the upper back pressure chamber 30 and the lower back pressure chamber 31 are always in communication via the communication passage 32 including the communication space 8 and the like outside the inner housing 9A, the communication between the inner housing 9A One of the ports p11 and p12 may be omitted, or a communication port that connects the valve chamber 7 and the communication space 8 may be formed at a position different from the communication ports p11 and p12.

[Fifth Embodiment]
13 and 14 are longitudinal sectional views showing a fifth embodiment of the flow path switching valve according to the present invention. FIG. 13 shows a first flow state (valve shaft: lowered position), and FIG. The flow state (valve shaft: ascending position) is shown.

  The flow path switching valve 5 of the fifth embodiment is basically different from the flow path switching valve 4 of the fourth embodiment in that the inner ports p1 to p5 and the communication ports p11 and p12 formed in the inner housing 9A are different. The shape near the inner circumference is different. Therefore, components having the same functions as those of the fourth embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Hereinafter, only the above-described differences will be described in detail.

  The flow path switching valve 5 of the present embodiment is used as a six-way switching valve in, for example, a heat pump type cooling / heating system or the like, similarly to the fourth embodiment. And three first connection shaft components 29A to 29C and one second connection shaft component 29D.

  Short cylindrical valve bodies (first valve body 21, second valve body 22, third valve body 23) are integrally formed at the upper end of each of the first connection shaft constituting bodies 29A to 29C. At the lower end, small-diameter fitting insertion portions 29Aa to 29Ca having the same shape as the small-diameter lower portion 27c of the thrust transmission shaft 27 are formed. Further, a short columnar valve body (fourth valve body 24) is integrally formed at the upper end of the second connection shaft constituting body 29D.

  The small-diameter lower portion 27c of the thrust transmission shaft 27 is fitted into the center hole 29Ab formed at the upper end portion of the first connection shaft constituting body 29A from the upper side and integrally connected by press-fitting, brazing, or the like. The small-diameter fitting portion 29Aa of the first connecting shaft component 29A is fitted into the center hole 29Bb formed at the upper end portion of the component 29B from above and integrally connected, and the upper end of the first connecting shaft component 29C. The small-diameter insertion portion 29Ba of the first connection shaft component 29B is fitted into the center hole 29Cb formed in the portion from above and integrally connected, and is formed at the upper end of the second connection shaft component 29D. The small-diameter insertion portion 29Ca of the first connection shaft component 29C is fitted into the center hole 29Db from above and integrally connected, so that the small-diameter insertion portion 29Ca is arranged along the axis O direction and Four short cylindrical column-shaped valve elements (first valve element 1, the second valve body 22, the third valve body 23, a fourth the valve shaft 20 to the valve body 24) is provided is configured.

  Here, the pressing member 21C is inserted between the upper end surface of the first valve body 21 of the first connecting shaft constituting body 29A and the lower end step surface of the intermediate body portion 27b of the thrust transmitting shaft 27 when the small-diameter lower portion 27c is press-fitted. The first valve element 21 (the outer peripheral surface) and the inner housing 9A (in the annular groove formed by the pressing member 21C and the step formed on the outer periphery of the upper end of the first valve element 21) are fixed. The seal member 21A for sealing a gap between the inner peripheral surface of the seal member (a sliding surface gap formed in the seal member) and the seal member 21A is mounted on the outside of the seal member 21A, and is made of PTFE (Teflon (registered trademark)) or the like. The packing 21B is mounted.

  In addition, between the second valve element 22 of the first connection shaft component 29B and the first connection shaft component 29A, the third valve member 23 of the first connection shaft component 29C and the first connection shaft component 29B are connected. Similarly, between the fourth valve element 24 and the first connection shaft component 29C of the second connection shaft component 29D, the holding members 22C to 24C are also sandwiched and fixed between the fourth valve body 24 and the first connection shaft component 29C. The seal members 22A to 24A and the packings 22B to 24B are mounted in annular grooves formed by the members 22C to 24C and the second to fourth valve bodies 22 to 24.

  Further, in the present embodiment, the portion where the inner ports p1 to p5 and the communication ports p11 and p12 are formed on the inner circumference of the inner housing 9A is formed in a concave shape over the entire circumference (the concave portions s1 to s5, s11, s12) (also referred to as recess processing), and tapered surface portions t1 to t5, t11, t12 each formed of a truncated conical surface are provided on the upper and lower surfaces of the concave portions s1 to s5, s11, s12.

  In the illustrated example, the tapered surface portions t1 to t5, t11, and t12 are formed of frustoconical surfaces and have a linear shape when viewed in a longitudinal cross section. Alternatively, it may be formed in a curved shape so as to project inward or outward when viewed in a longitudinal section. Further, the boundary between the inner ports p1 to p5 and the communication ports p11 and p12 and the inner housing 9A, or the boundary between the tapered surface portions t1 to t5, t11 and t12 and the inner housing 9A may be rounded.

  Also in the flow path switching valve 5 having such a configuration, when the rotor 57 of the stepping motor 50 is rotationally driven, each of the valve bodies (the first valve body 21, the second valve body 22, the third valve body 23, and the fourth valve body 24). The valve shaft 20 is moved up and down in the valve chamber 7 in a state in which the inner shaft is inscribed in the inner housing 9A, so that the five inner ports p1, p2, p3, p4, p5 and The communication state (flow direction, flow path) between the outer port p10 is switched, but the communication path 32 including the communication space 8 between the inner housing 9A and the outer housing 9 (in other words, outside the inner housing 9A) is switched. Since the upper back pressure chamber 30 defined above the first valve body 21 and the lower back pressure chamber 31 defined below the fourth valve body 24 are always in communication with each other, The same operation and effect as in the fourth embodiment can be obtained.

  Further, in the present embodiment, concave portions s1 to s5, s11, and s12 are provided over the entire circumference at portions where the inner ports p1 to p5 and the communication ports p11 and p12 are formed on the inner circumference of the inner housing 9A. Therefore, the outer circumference of each valve body (including the packings 21B, 22B, 23B, 24B and the sealing members 21A, 22A, 23A, 24A provided on the outer circumference of each valve body) and the inner housing 9A at the time of switching the flow path. Since the sliding resistance with the periphery can be reduced, the load acting on the valve body at the time of switching the flow path can be reduced as much as possible, and the driving torque of the valve body can be reduced more effectively.

  In addition, PTFE (Teflon) having relatively high hardness is provided outside the seal members 21A, 22A, 23A, and 24A provided on the outer periphery of each valve body in order to suppress elastic deformation of the seal members 21A, 22A, 23A, and 24A. (Registered trademark)) or the like, but the seal members 21A, 22A, 23A, 24B are elastic when the seal members 21A, 22A, 23A, 24B pass over the inner ports and the communication ports at the time of switching the flow path. It is possible that the packings 21B, 22B, 23B, 24B and the outer peripheral portions of the seal members 21A, 22A, 23A, 24A protrude from the annular grooves formed on the outer periphery of each valve body. In the present embodiment, tapered surface portions t1 to t5, t11, and t12 each having a truncated conical surface are provided at (upper and lower) portions of the inner periphery of the inner housing 9A where the inner ports p1 to p5 and the communication ports p11 and p12 are formed. 15, the packings 21B, 22B, 23B, and 24B and the seal members 21A, 22A, 23A, and 24A smoothly move over the inner ports and the communication ports when the flow path is switched, for example, as shown in an enlarged view in FIG. And the resistance when the packings 21B, 22B, 23B and 24B and the sealing members 21A, 22A, 23A and 24A pass over the respective inner ports and the communication ports (in the illustrated example, the respective inner ports and the communication ports). Resistance due to a step between the concave portion provided in the portion where the is formed and the inner periphery of the inner housing can be further reduced. Because, this also, the flow path switching can be reduced as much as possible the loads acting on the valve element, can be further effectively reduce the driving torque of the valve body.

[Sixth embodiment]
16 and 17 are longitudinal sectional views showing a sixth embodiment of the flow path switching valve according to the present invention. FIG. 16 shows a first flow state (valve shaft: lowered position), and FIG. The flow state (valve shaft: ascending position) is shown.

  The flow path switching valve 6 of the sixth embodiment is basically different from the flow path switching valve 1 of the first embodiment in the number of inner ports formed in the inner housing and the number of valve bodies formed in the valve shaft. Are different. Therefore, components having the same functions as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted. Only the differences described above will be described in detail below.

  The flow path switching valve 6 of the present embodiment is used as a three-way switching valve in, for example, a heat pump cooling / heating system and the like, and two side-by-side parts of the inner housing 9A are arranged side by side in the direction of the axis O (vertical direction). The inner ports p1 and p2 are opened, and a communication port p11 that connects the valve chamber 7 and the communication space 8 is opened above the upper inner port p1, and a valve is provided below the lower inner port p2. A communication port p12 for communicating the chamber 7 with the communication space 8 is opened. More specifically, the communication port p11 is formed so as to be located above the first valve body 21 when the valve shaft 20 is at the raised position, and the communication port p12 is formed when the valve shaft 20 is at the lowered position. It is formed so as to be located below the second valve body 22. That is, here, the communication port p11 is formed so as to be always located above the first valve body 21, and the communication port p12 is formed so as to be always located below the second valve body 22. Conduit fittings # 1 and # 2 are attached to the inner ports p1 and p2, respectively (to penetrate the outer housing 9), such as by brazing, in a lateral direction.

Further, the intermediate body portion 27b of the thrust transmission shaft 27 constituting the valve shaft 20 is formed to be slightly longer, and the connection shaft 29 connected to (the small-diameter lower portion 27c thereof) is separated from the thrust transmission shaft 27 in the direction of the axis O. As a result, two short columnar valve bodies (a first valve body 21 and a second valve body 22) are integrally formed. Each valve element (the first valve element 21 and the second valve element 22) is separated by a distance substantially equal to the hole diameter of the two inner ports p1 and p2 opened in the inner housing 9A. The connection shaft 29 is provided between the valve bodies so as to define a space having a size communicating with one of the two inner ports p1 and p2 opened to the inner housing 9A. . The first valve body 21, between the inner port p1 and the communication port p 11 at the time when the two between and valve shaft 20 of the inner port p1, p2 in when the valve shaft 20 is in the lowered position in the raised position The second valve element 22 is disposed between the inner port p2 and the communication port p12 when the valve shaft 20 is at the lowered position and when the valve shaft 20 is at the raised position. At the connection shaft 29 so as to be located between the two inner ports p1 and p2.

  In this example, the first valve body 21 is formed at the upper end of the connection shaft 29, and the second valve body 22 is formed at the lower end thereof. Also in the present embodiment, seal members 21A and 22A such as O-rings are mounted in annular grooves formed on the outer periphery of each valve body (the first valve body 21 and the second valve body 22). Ring-shaped packings (also referred to as cap seals) 21B and 22B made of PTFE (Teflon (registered trademark)) or the like are mounted outside the members 21A and 22A.

  Even in the flow path switching valve 6 having such a configuration, when the rotor 57 of the stepping motor 50 is rotationally driven, the respective valve bodies (the first valve body 21 and the second valve body 22) are in contact with the inner housing 9A. As the valve shaft 20 moves up and down in the valve chamber 7, the communication state (flow direction, flow path) between the two inner ports p1, p2 and the outer port p10 is switched.

  That is, when the rotor 57 of the stepping motor 50 is driven to rotate in one direction, the valve shaft 20 is moved to the lowered position (here, the second valve body 22 is provided at the lower end of the valve shaft 20), as in the first embodiment. At this lowered position, the first valve element 21 is located between the inner port p1 and the inner port p2, and the second valve The body 22 is located between the inside port p2 and the communication port p12, and the space between the first valve body 21 and the second valve body 22 is located right beside the inside port p2. Accordingly, the inside port p1 and the outside port p10 communicate with each other via the space (upper back pressure chamber 30) above the first valve body 21 in the valve chamber 7, the communication port p11, and the communication space 8, and the valve chamber 7 , A space above the first valve body 21 (upper back pressure chamber 30), a communication passage 32A provided in the valve shaft 20 (a lateral hole 27e and a through hole 27d of the thrust transmission shaft 27, and a through hole 29a of the connection shaft 29). ), The vertical hole 11v and the horizontal hole 11u of the (small-diameter projecting portion 11a of) the lid member 11, the space below the second valve body 22 in the valve chamber 7 (the lower back pressure chamber 31), the communication port p12, The communication is established via the communication space 8 (first flow state shown in FIG. 16).

  On the other hand, when the rotor 57 of the stepping motor 50 is driven to rotate in the other direction, the valve shaft 20 assumes the ascending position, as in the first embodiment. At this ascending position, the first valve element 21 is connected to the communication port p11. And the inside port p1, the second valve body 22 is positioned between the inside port p1 and the inside port p2, and the space between the first valve body 21 and the second valve body 22 is It is located right beside the port p1. Thereby, the inside port p2 and the outside port p10 communicate with each other via the space (lower back pressure chamber 31) below the second valve body 22 in the valve chamber 7, the communication port p12, and the communication space 8, and The space below the second valve body 22 in the chamber 7 (lower back pressure chamber 31), the communication passage 32A provided in the valve shaft 20 (the lateral hole 27e and the through hole 27d of the thrust transmission shaft 27, the connection shaft 29). Through the through hole 29a), the space above the first valve body 21 in the valve chamber 7 (upper back pressure chamber 30), the communication port p11, and the communication space 8 (the second flow state shown in FIG. 17).

  Here, also in the present embodiment, a communication passage 32A provided in the valve shaft 20 and a communication passage 32B including the communication space 8 between the inner housing 9A and the outer housing 9 (specifically, the inner housing 9A Upper side defined on the upper side of the first valve body 21 through the two communication ports p11 and p12 and the communication path 32B) formed by the communication space 8 between the inner housing 9A and the outer housing 9. Since the back pressure chamber 30 and the lower back pressure chamber 31 defined below the second valve body 22 are always in communication, the same operational effects as in the first embodiment can be obtained.

  In this case, since the upper back pressure chamber 30 and the lower back pressure chamber 31 are always in communication via the communication passage 32B including the communication space 8 and the like outside the inner housing 9A, the fourth embodiment is described. Similarly to the above, it is a matter of course that the communication shaft 32A provided in the valve shaft 20 may be omitted by forming the connection shaft 29 constituting the valve shaft 20 substantially solid.

  Further, by adopting a configuration similar to that of the flow path switching valve 6 of the sixth embodiment, a flow path switching valve that switches the flow direction (flow path) of the fluid (refrigerant) in an odd number direction, such as a five-way switching valve, is provided. It goes without saying that it can be configured.

  In the above-described first to sixth embodiments, an electric-type flow path switching valve using a stepping motor having a stator and a rotor is mainly used as an elevating drive unit for elevating the valve body. Needless to say, for example, an electromagnetic flow path switching valve using a solenoid or the like may be employed as the lifting drive unit.

1 flow path switching valve (first embodiment)
2 flow path switching valve (second embodiment)
3. Flow path switching valve (third embodiment)
4. Flow path switching valve (fourth embodiment)
5 flow path switching valve (fifth embodiment)
6. Flow path switching valve (sixth embodiment)
7 valve chamber 8 communication space 9 outer housing 9A inner housing 10 valve body 11 lid member 20 valve shaft 21 first valve body 22 second valve body 23 third valve body 24 fourth valve body 21A to 24A sealing members 21B to 24B Packing 27 Thrust transmitting shaft 29 Connecting shaft 30 Upper back pressure chamber 31 Lower back pressure chamber 32 Communication passage 40 Mysterious planetary gear type reduction mechanism 50 Stepping motor (elevation drive unit)
55 Stator 57 Rotor 58 Can p1-p5 Inner port p10 Outer port p10a Opening p11, p12 Communication port # 1- # 5, # 10 Pipe joint

Claims (13)

A cylindrical inner housing having a valve chamber;
An outer housing disposed outside the inner housing to form a communication space outside the inner housing;
A valve shaft that is arranged in the valve chamber so as to be able to move up and down, and at least two valve bodies inscribed in the inner housing are provided in the axial direction so as to be separated from each other;
A lifting drive for raising and lowering the valve shaft in the valve chamber,
Spaced to the inner housing, with at least two inner ports open to the valve chamber is made to open by axially spaced, two communication ports axially constantly communicating the said valve chamber said communication space And let me open it,
In the outer housing, an outer port that is always in communication with the communication space is opened.
An upper back pressure chamber defined above the at least two valve bodies in the valve chamber and a lower back pressure chamber defined below the at least two valve bodies in the valve chamber; It is always in communication via a communication passage provided in the shaft ,
A communication between the at least two inner ports and the outer port by raising and lowering the valve shaft in the valve chamber by the elevating drive unit in a state where the at least two valve bodies are inscribed in the inner housing. The state can be switched ,
In the lowered position and raised position of the valve shaft, one of the two communication ports are communicated with said communication passage, characterized Rukoto other of the two communicating ports communicating with the one of the at least two inner ports Flow path switching valve.   The flow path switching valve according to claim 1, wherein the communication space is formed on an outer periphery of the inner housing or is formed on a part of an outer periphery of the inner housing. D-cut surface is provided on an outer periphery of said inner housings in g, the flow path of claim 1, wherein the communicating space is formed by the inner peripheral surface of said outer housing and said D-cut surface Switching valve.   The flow path switching according to any one of claims 1 to 3, wherein the at least two inner ports and the outer port are opened on opposite sides or the same side as viewed in the axial direction. valve.   The communication port is located above the at least two inner ports and below the at least two inner ports, and has a distance equal to a distance between an uppermost valve element and a lowermost valve element of the at least two valve elements. The flow path switching valve according to any one of claims 1 to 4, wherein the flow path switching valve is opened at intervals.   The outer port is opened to the communication space and is always in communication with the communication space, or the communication is performed through an opening that is opened at the same height as the communication port in the inner housing. The flow path switching valve according to any one of claims 1 to 5, wherein the flow path switching valve is configured to always communicate with a space. The lifting drive unit, any one of 6 claim 1, characterized in that it is a stepping motor having a stator for rotating the rotor and the rotor connected integrally with the valve shaft 3. The flow path switching valve according to claim 1. With the seal member is mounted on the outer periphery of said at least two valve bodies, any one of claims 1 to high packing hardness than the seal member on the outer side of the seal member is characterized in that it is fitted 7 one Item 7. A flow path switching valve according to Item 1. The concave part is provided in the part in which the at least two inside ports and the two communication ports were formed in the inner circumference of the inside housing, The statement according to any one of claims 1 to 8 characterized by things. Flow path switching valve. The flow path switching valve according to claim 9 , wherein a tapered surface portion is provided on an upper surface and / or a lower surface of the concave surface portion. The flow path switching valve according to any one of claims 1 to 10 , wherein the valve shaft is configured to include a plurality of connection shaft components each provided with one valve element. . The flow path switching according to any one of claims 1 to 11 , wherein a lid-like member having a stopper for restricting the lowering of the valve shaft is attached to the outer housing or the inner housing. valve. The lid-shaped member is provided in the valve shaft so that the upper back pressure chamber and the lower back pressure chamber always communicate with each other when the valve shaft comes into contact with the stopper portion and is stopped. The flow path switching valve according to claim 12 , wherein a vertical hole and a horizontal hole communicating with the communication path are provided.

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