JP2009068695A - Selector valve, and reversible cycle refrigerator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a selector valve capable of smoothly moving a valve element changing over a flow between pipes, and a reversible cycle refrigerator. <P>SOLUTION: An air conditioner as this reversible cycle refrigerator is provided with the selector valve 2. The selector valve 2 is provided with a valve body with a plurality of pipes attached thereto, and a piston body 7. The piston body 7 is provided with: a piston main body 17 housed in the valve body movably along the axis of the valve body; packing 18 arranged at both ends of the piston main body 17 and sealing a part between the valve body and itself; and the valve element arranged at the center of the piston main body 17 and changing flows among the plurality of pipes. The packing 18 has an inclined part 28 formed into an annular shape, and inclined in a direction gradually coming close to the inner surface of a cylindrical part of the valve body as its cross-sectional shape approaches the end of the valve body. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to, for example, a switching valve that switches between cooling and heating of a reversible cycle refrigeration apparatus and a reversible cycle refrigeration apparatus including the switching valve.

  Conventionally, in an air conditioner as a reversible cycle refrigeration apparatus that can be switched between cooling and heating, a compressor, two heat exchangers used as a condenser or an evaporator, these compressors and two heat exchangers, And a switching valve (shown in FIG. 12 and FIG. 13) 100 that switches the flow path of the refrigerant.

  The switching valve 100 illustrated in FIGS. 12 and 13 includes a cylindrical valve body 101 and a piston body 102 accommodated in the valve body 101. One valve 103 is attached to the valve body 101 in the upper part in FIG. 12, and three pipes 103 are attached to the lower part in FIG. These three pipes 103 are arranged in parallel to each other. Further, both ends of the valve body 101 are closed by plugs 104. The valve body 101 is provided with a valve seat 105 that communicates the inside and outside of the valve body 101.

  The piston body 102 includes a piston main body 106, a pair of packings 107, and a single valve body 108. The piston body 106 is accommodated in the valve body 101 so as to be movable along the axis of the valve body 101. The packing 107 is provided at both ends of the piston body 106 and seals between the spaces located on both sides of the packing 107 partitioned by the packing 107 on the inner surface of the valve body 101. The valve body 108 is provided in the central portion of the piston main body 106 and allows the flow direction (that is, the flow) between the plurality of pipes 103 to be changed.

  The packing 107 is formed in a disk shape. The packing 107 is provided with an inclined portion 109 that is inclined in a direction gradually approaching the inner surface of the valve body 101 as it goes toward the center of the valve body 101 in the axial direction. The packing 107 is urged toward the inner surface of the valve main body 101 by a leaf spring 110 having an inclined portion 109 made of a thin metal plate having elasticity. In the packing 107, the inclined portion 109 is in close contact with the inner surface of the valve main body 101 to keep fluid tightness with the inner surface of the valve main body 101.

  The switching valve 100 having the above-described configuration includes a pilot valve 111 having an electromagnet, and a pressure difference between both ends of the valve body 101 and the packing 107 depending on whether a voltage is applied to the coil of the electromagnet. Is changed, and the piston body 102 moves. Specifically, the pressure between one end of the valve main body 101 and one packing 107 of the pair of packings 107 is increased, and the other end of the valve main body 101 and the other packing of the pair of packings 107 are increased. The pressure between the piston body 102 and the other end portion of the valve body 101 and the other packing 107 of the pair of packings 107 is reduced by reducing the pressure between the piston body 102 and the other end portion. And the pressure between one end of the valve body 101 and one packing 107 of the pair of packings 107 is reduced, so that the piston body 102 approaches the one end described above. The piston body 102 moves in the valve body 101 by moving in the direction. In the switching valve 100, the piston body 102 moves, so that the valve body 108 changes the flow direction of the refrigerant in the plurality of pipes 103 and switches between cooling and heating of the air conditioner.

In the conventional air conditioner switching valve 100 described above, the pressure between one end of the valve main body 101 and one packing 107 of the pair of packings 107 is increased, and the other end of the valve main body 101 is By reducing the pressure between the other packing 107 of the pair of packings 107, the piston body 102 is moved in the direction approaching the other end described above, and the other end of the valve body 101 is paired with the pair of packings 107. By increasing the pressure between the other packing 107 of the packing 107 and decreasing the pressure between one end of the valve body 101 and one packing 107 of the pair of packings 107, the piston body 102 is The piston body 102 moves in the valve body 101 by moving in the direction approaching the one end described above. Further, the inclined portion 109 of the packing 107 of the piston body 102 is inclined in the above-described direction.

  On the other hand, the space surrounded by the piston body 102 and the pair of packings 107 is always in communication with the discharge-side high pressure of the compressor, and the packing 107 prevents the compressed discharge-side high-pressure refrigerant from flowing through the suction-side low pressure. It needs a sealing property.

  For this reason, the pressure between the pair of packings 107 of the piston body 102 is pressed in a direction in which the inclined portion 109 of the packing 107 on the front side in the moving direction of the piston body 107 expands.

  Therefore, when the piston body 102 moves, the inclined portion 109 of the packing 107 on the front side in the moving direction of the piston body 102 is expanded, so that the sliding resistance increases and the movement of the piston body 102 is prevented. The packing 107 receives a large load due to a pressure difference. Therefore, in the conventional switching valve 100, it is difficult to smoothly move the piston body 102, and it is difficult to smoothly switch the flow between the pipes 103. Further, the seal portion of the packing 107 is damaged due to repeated switching operation under a large load due to a pressure difference, and there is a problem that durability is inferior.

  Accordingly, an object of the present invention is to provide a switching valve and a reversible cycle refrigeration apparatus that can smoothly move a valve body that switches the flow between pipes and that can improve the durability of the packing. .

  In order to solve the problems and achieve the object, the switching valve according to the first aspect of the present invention is a cylindrical valve body to which a plurality of pipes are attached, and is movable along the axis of the valve body. The piston main body housed in the valve main body, the packing provided at both ends of the piston main body to contact the valve main body, and the flow between the plurality of pipes provided at the central portion of the piston main body are changed. A switching body in which the valve body changes a flow between the plurality of pipes by moving the piston body along an axis of the valve body. The packing is characterized in that it is formed in an annular shape and has an inclined portion that is inclined in a direction in which its cross-sectional shape gradually approaches the inner surface of the valve body as it goes toward the end of the valve body.

  A switching valve according to a second aspect of the present invention is the switching valve according to the first aspect, wherein both end portions of the valve body are provided with valve seats communicating with the inside and the outside of the valve body, and the piston At both ends of the main body, there is provided a second valve body that comes into close contact with the valve seat and closes the valve seat when approaching the end of the valve main body.

  A switching valve according to a third aspect of the present invention is the switching valve according to the first or second aspect, wherein the inclined portion of the packing is separated from the inner surface of the valve main body at both ends of the piston main body. It is characterized in that a restricting member for restricting excessiveness is attached.

A reversible cycle refrigeration apparatus according to a fourth aspect of the present invention includes a compressor, a heat exchanger connected to the compressor, and a switching valve connected to the compressor and the heat exchanger. In the cycle refrigeration apparatus, the switching valve according to any one of claims 1 to 3 is provided as the switching valve.

  According to the first aspect of the present invention, the inclined portion of the packing is gradually inclined toward the inner surface of the valve body as it approaches the end of the valve body. The inclined portion of the packing located on the front side is pressed in a direction in which it is contracted when the piston body moves.

  According to the second aspect of the present invention, since the second valve body for closing the valve seats provided at both ends of the valve body is provided at both ends of the piston body, the piston body is The valve body is reliably positioned at a predetermined position where the valve seat closes the valve seat.

  According to the third aspect of the present invention, the restricting member for restricting the inclined portion from being separated from the inner surface of the valve main body is provided, so that the inclined portion can be prevented from being plastically deformed.

  According to the present invention described in claim 4, since the switching valve described above is provided, the inclined portion of the packing located on the front side in the moving direction of the piston body of the switching valve is moved when the piston body moves. Pressed in the direction of contraction.

  As described above, in the present invention according to claim 1, the inclined portion of the packing located on the front side in the moving direction of the piston body is pressed in a direction to be contracted when the piston body moves. The front packing does not hinder the movement of the piston body. Therefore, the piston body, that is, the valve body can be moved smoothly, and the flow between the pipes can be switched smoothly. Further, in the conventional example described in the background art section, the sealability is required for the packing. However, in the present invention, since the second valve body seals, the sealing performance of the packing can be reduced and the durability of the packing is improved. To do.

  According to the second aspect of the present invention, since the piston body can be reliably positioned at a predetermined position where the second valve body closes the valve seat, the valve body can reliably switch the flow between the pipes.

  According to the third aspect of the present invention, since the inclined portion can be prevented from being plastically deformed, the inclined portion, that is, the packing can be prevented from being damaged.

  Since the present invention according to claim 4 includes the switching valve described above, the flow of the refrigerant in the reversible cycle refrigeration apparatus can be smoothly switched.

  Hereinafter, a switching valve according to an embodiment of the present invention and an air conditioner as a reversible cycle refrigeration apparatus including the switching valve will be described with reference to FIGS. 1 to 10.

  The air conditioner 1 according to the present embodiment uses, for example, carbon dioxide as a refrigerant (corresponding to a fluid). In the air conditioner 1, carbon dioxide as a refrigerant is compressed to a pressure of, for example, about 10 MPa by a compressor 4 described later. As shown in FIGS. 1 and 2, the air conditioner 1 includes a switching valve 2, a pilot valve 3, a compressor 4, two heat exchangers 5, and an expansion valve 40.

As shown in FIGS. 1 and 2, the switching valve 2 includes a valve body 6 and a piston body 7. The valve body 6 includes a cylindrical portion 8, two end caps 9, a plurality of pipes 10, and a valve plate 11. Of course, the cylindrical portion 8 is formed in a cylindrical shape having a constant inner and outer diameter. Each of the end caps 9 is formed in a disk shape, and is attached to the end of the cylindrical portion 8 by welding to close the end. A bleed exhaust pipe 12 that passes through the center of the end cap 9 is attached to the end cap 9. An inner end 12a of the cylindrical portion 8 of the extraction pipe 12 serves as a valve seat described in the claims. For this reason, the valve body 6 is provided with valve seats at both ends thereof.

  In the illustrated example, four pipes 10 are provided. Each of the four pipes 10 is attached to the central portion of the cylindrical portion 8 of the valve body 6 in the axial center (longitudinal) direction, and communicates the inside and the outside of the cylindrical portion 8. These pipes 10 are arranged in a fashion extending linearly from the outer peripheral surface of the cylindrical portion 8 of the valve body 6 in the outer peripheral direction. Of the four pipes 10, three pipes 10 (hereinafter denoted by reference numerals 10a, 10b, and 10c) are parallel to each other and spaced apart from each other along the axial direction (longitudinal) direction of the cylindrical portion 8, that is, the valve body 6. Are arranged. In the illustrated example, the remaining one pipe 10 (hereinafter denoted by reference numeral 10d) sandwiches the center pipe 10b of the three pipes 10a, 10b, and 10c and the cylindrical portion 8, that is, the axis of the valve body 6. It is relative.

  The pipes 10 b and 10 d are connected to each other by a conduit 13 through the compressor 4. The pipes 10 a and 10 c are connected to two heat exchangers 5 and 5 by a conduit 15, respectively, and the two heat exchangers 5 and 5 are connected by a conduit 14 via an expansion valve 40.

  The valve plate 11 is formed in a thick flat plate shape and is attached to the central portion of the inner peripheral surface of the cylindrical portion 8 of the valve body 6. The valve plate 11 is provided with a valve seat port 16 communicating with each of the three pipes 10a, 10b, 10c.

  The piston body 7 is accommodated in the valve body 6, is formed shorter than the cylindrical portion 8 of the valve body 6, and as shown in FIGS. 1 and 2, a piston body 17, a valve body 21, A pair of pistons 50 is provided. The piston 50 includes a disc portion 24, a regulating member 18, a packing 19, a leaf spring 20 as a biasing means, and a ball 22 as a pair of second valve bodies. The piston main body 17 includes a flat plate portion 23, and the flat plate portion 23 is formed in a band plate shape whose longitudinal direction is parallel to the cylindrical portion 8 of the valve main body 6. The piston 50 is attached to both ends in the longitudinal direction of the flat plate portion 23 by screws 26.

  Each of the regulating members 18 is thick and is formed in a disk shape having the same diameter as the disk portion 24. The restricting member 18 is disposed coaxially with the disc portion 24. The restricting member 18 is stacked on the disc portion 24 and is fixed to the disc portion 24 with a rivet 25. The regulating member 18 may come into contact with the outer peripheral surface of the inclined portion 28 (described later) of the packing 19 via the leaf spring 20. The restricting member 18 restricts the inclined portion 28 from being too far from the inner surface of the cylindrical portion 8 of the valve body 6 and restricts the inclined portion 28 and the leaf spring 20 from being plastically deformed.

  The packing 19 is made of synthetic resin, and integrally includes a disk-shaped disk part 27 and an inclined part 28 as shown in FIG. The outer diameter of the disk part 27 is substantially the same as that of the disk part 24 and the regulating member 18. The disc portion 27, that is, the packing 19 is disposed coaxially with both the disc portion 24 and the restricting member 18, and is sandwiched between them, so that the disc portion 24 and the restricting member 18 are separated by the rivets 25. It is fixed with both sides.

  The inclined portion 28 is formed in an annular shape (that is, in an annular shape) and is provided over the entire circumference of the outer edge of the disc portion 27. The inclined portion 28 extends from the outer edge of the disc portion 24 toward the end of the valve body 6 and the inner surface of the cylindrical portion 8 of the valve body 6. That is, the inclined portion 28 has both the axial direction and the radial direction of the valve main body 6 in a direction in which the cross-sectional shape gradually approaches the inner surface of the cylindrical portion 8 of the valve main body 6 as the cross-sectional shape approaches the end of the valve main body 6. It is inclined with respect to.

  The packing 19 is elastically deformable so that the end of the inclined portion 28 on the side away from the disc portion 27 contacts and separates from the inner surface of the cylindrical portion 8 of the valve body 6. Further, when the packing 19 is incorporated in the cylindrical portion 8 of the valve body 6, the end of the inclined portion 28 on the side away from the disc portion 27 extends over the entire circumference of the cylindrical portion 8 of the valve body 6. The inner surface of the valve main body 6 is in close contact with the inner surface of the cylindrical portion 8 so as to be fluid-tight (that is, airtight or liquid-tight). As described above, the packing 19 is provided at both ends of the piston body 17 and contacts the inner surface of the cylindrical portion 8 of the valve body 6.

  The leaf spring 20 is formed of a thin metal plate that can be elastically deformed, and includes a disc-shaped disc portion 29 and an inclined biasing portion 30 integrally. The outer diameter of the disc portion 29 is substantially the same as that of the disc portions 24 and 27 and the regulating member 18. The disc portion 29, that is, the leaf spring 20, is disposed coaxially with all of the disc portions 24 and 27 and the regulating member 18, and is sandwiched between the regulating member 18 and the disc portion 27 of the packing 19. The rivets 25 are fixed to all the disk portions 24 and 27 and the regulating member 18.

  The inclined urging portion 30 is formed in an annular shape (that is, in an annular shape) and is provided over the entire circumference of the outer edge of the disc portion 29. The inclined urging portion 30 extends from the outer edge of the disc portion 29 toward the end of the valve body 6 and the inner surface of the cylindrical portion 8 of the valve body 6. That is, the inclined biasing portion 30 is formed so that its axial shape gradually approaches the inner surface of the cylindrical portion 8 of the valve body 6 as its cross-sectional shape approaches the end of the valve body 6. Inclined with respect to both.

  The leaf spring 20 has an end on the side away from the disc portion 29 of the inclined biasing portion 30 via the inclined portion 28 of the packing 19, and the inclined portion 28 contacts and separates from the inner surface of the cylindrical portion 8 of the valve body 6. Thus, it is elastically deformable. Further, the leaf spring 20 generates an elastic restoring force that urges the inclined portion 28 of the packing 19 that is separated from the inner surface of the cylindrical portion 8 of the valve body 6 toward the inner surface of the cylindrical portion 8 of the valve body 6. When the leaf spring 20 is incorporated in the cylindrical portion 8 of the valve body 6, the end of the inclined biasing portion 30 on the side away from the disc portion 29 causes the inclined portion 28 of the packing 19 to be in the cylindrical portion of the valve body 6. 8 is pressed toward the inner surface.

  The valve body 21 is attached to the central portion of the flat plate portion 23 of the piston body 17 and is formed in a concave bowl shape from the valve plate 11. That is, the valve body 21 is provided in the central portion of the piston body 17. As will be described later, when the piston body 7 moves along the longitudinal direction of the valve body 6, the valve body 21 communicates two of the three pipes 10a, 10b, and 10c with each other, and the three pipes 10a. , 10b and 10c are kept fluid-tight between the two and the inside of the cylindrical portion 8 of the valve body 6 is blocked from each other.

  Therefore, as shown in FIG. 1, when the piston body 17, that is, the piston body 7 is positioned at the left end in FIG. 1 of the cylindrical portion 8 of the valve body 6, the valve body 21 communicates the pipes 10a and 10b with each other. In addition, the pipes 10c and 10d communicate with each other, and the pipes 10a and 10b and the pipes 10c and 10d are blocked from each other. As shown in FIG. 2, when the piston body 17, that is, the piston body 7 is positioned at the right end in FIG. 1 of the cylindrical portion 8 of the valve body 6, the valve body 21 communicates the pipes 10 b and 10 c, and The pipes 10a and 10d communicate with each other, and the pipes 10b and 10c and the pipes 10a and 10d are blocked from each other. As described above, the valve body 21 moves as the fluid between the plurality of pipes 10a, 10b, 10c, and 10d as the piston body 17, that is, the piston body 7 moves along the axial center of the cylindrical portion 8 of the valve body 6. The flow direction (that is, the flow) of the refrigerant is changed.

Two balls 22 are provided. Each of the balls 22 is attached to the center of the regulating member 18 and is provided so as to be convex and concave from the regulating member 18 toward the end cap 9. Further, as shown in FIG. 3, the ball 22 is urged by a coil spring 31 in a direction protruding from the end cap 9, and the end portion is supported by a hook-like portion indicated by reference numeral 32 in FIG. 3. Dropping from the cap 9 side is restricted.

  When the piston body 7 moves in the axial direction of the valve body 6 and approaches the end 12a of the bleed exhaust pipe 12 as a valve seat provided on the opposite end cap 9, the ball 22 approaches the end 12a. The end 12a, that is, the extraction exhaust pipe 12 is closed.

  In the piston body 7 described above, the packing 19 comes into contact with the inner surface of the cylindrical portion 8 of the valve body 6, so that the space in the valve body 6 is changed from the left side in FIGS. The chamber 34 and the second outer chamber 35 are partitioned. Further, the piston body 17 of the piston body 7 is formed so that its entire length is shorter than that of the cylindrical portion 8, so that the cylindrical portion of the valve body 6 can be moved along the axial center of the cylindrical portion 8 of the valve body 6. 8 is housed.

  The pilot valve 3 has an electromagnet, and is connected to the extraction pipes 12 and 12 described above, the exhaust pipe 36 attached to the pipe 10b, and the extraction pipe 37 attached to the pipe 10d. The pilot valve 3 supplies the refrigerant compressed by the compressor 4 supplied from the extraction pipe 37 attached to the pipe 10d to the one extraction pipe 12 depending on whether a voltage is applied to the coil of the electromagnet. At the same time, the other extraction pipe 12 is discharged to the suction side of the compressor 4 by the exhaust pipe 36 attached to the pipe 10b, and the other extraction pipe 12 is supplied to the other extraction pipe 12. Switch to the state of discharging from. That is, the pilot valve 3 supplies the refrigerant compressed by the compressor 4 supplied from the extraction pipe 37 attached to the pipe 10d to the two extraction pipes 12 depending on whether or not a voltage is applied to the coil of the electromagnet. , 12 is supplied to one of the above-described outer chambers 33, 35, and the other of the two outer chambers 33, 35 is connected to the other of the two extraction pipes 12. To the suction side of the compressor 4.

  The compressor 4 is provided in the conduit 13 connected to the pipes 10b and 10d described above. The two heat exchangers 5 function as a condenser (a gas cooler when the refrigerant is carbon dioxide) or an evaporator, and one of the heat exchangers 5 is switched via a conduit 15 connected to the pipe 10a. The other heat exchanger 5 connected to the valve 2 is connected to the switching valve 2 via a conduit 15 connected to the pipe 10c. Furthermore, the two heat exchangers 5 are connected to each other by a conduit 14. Thus, the compressor 4 and the heat exchangers 5 and 5 are connected to each other via the switching valve 2, the expansion valve 40, and the conduits 13, 14, and 15, and the air conditioner 1 that is a reversible cycle refrigeration apparatus is configured. Yes.

  The air conditioner 1 having the above-described configuration is disposed outside a building or the like so that one heat exchanger 5 exchanges heat with outdoor air, and the other heat exchanger 5 is connected to the air inside the room or the refrigerator. It is arranged in a room such as a building so as to perform heat exchange.

  And the air conditioner 1 supplies the refrigerant | coolant compressed by the compressor 4 to the 1st outer chamber 33 via the extraction pipe 12 by whether a voltage is applied to the coil of the electromagnet of the pilot valve 3. The state and the state of supplying to the second outer chamber 35 via the extraction pipe 12 are switched. The air conditioner 1 moves the valve body 21 along with the piston body 7 along the axial center of the valve body 6 to reverse the refrigerant flow direction (that is, the flow) between the two heat exchangers 5.

  In the air conditioner 1, when the room is cooled, the heat exchanger 5 disposed in the room operates as an evaporator to cool the room, and when the room is heated, the heat exchanger 5 disposed in the room. Operates as a condenser (or a gas cooler if the refrigerant is carbon dioxide) to warm the room. As described above, the air conditioner 1 moves the valve body 21 together with the piston body 7 of the switching valve 2 by the pilot valve 3 to switch the direction in which the refrigerant flows between the heat exchangers 5 and 5. Switch.

  Hereinafter, the operation of the switching valve 2 described in the above-described embodiment will be described. First, in a state where a voltage is applied to the electromagnet coil of the pilot valve 3, the pilot valve 3 passes high pressure refrigerant from the discharge side of the compressor 4 through the extraction pipe 37, the pilot valve 3, and the extraction exhaust pipe 12. While being supplied into the first outer chamber 33, the pressure in the second outer chamber 35 is discharged to the low-pressure suction side of the compressor 4 through the extraction exhaust pipe 12, the pilot valve 3 and the exhaust pipe 36. Then, as shown in FIG. 5, the piston body 7, that is, the valve body 21 is positioned at the right end of the valve body 6 in the figure, and the valve body 21 connects the pipes 10 b and 10 c to each other, Then, the pipes 10a and 10d are connected to each other. That is, in the state shown in FIG. 5, the refrigerant in the first outer chamber 33 is kept at a high pressure, and the refrigerant in the second outer chamber 35 is kept at a low pressure.

  When the application of the electromagnet of the pilot valve 3 to the coil of the pilot valve 3 is stopped in the state shown in FIG. 5, the pilot valve 3 supplies the high-pressure refrigerant from the discharge side of the compressor 4, the extraction pipe 37, the pilot valve 3. The pressure is supplied to the second outer chamber 35 through the extraction pipe 12 and the pressure in the first outer chamber 33 is discharged to the low pressure suction side of the compressor 4 through the extraction pipe 12, the pilot valve 3, and the exhaust pipe 36. Therefore, the pressure in the first outer chamber 33 decreases. Then, since the discharge-side high-pressure refrigerant of the compressor 4 is always supplied into the central chamber 34, the central chamber is caused by the difference between the refrigerant pressure in the central chamber 34 and the refrigerant pressure in the first outer chamber 33. The pressurized refrigerant in 34 presses the inclined portion 28 of the packing 19 on the left side in the drawing in a direction away from the inner surface of the cylindrical portion 8 of the valve body 6 against the elastic restoring force of the leaf spring 20.

  Then, as shown in FIG. 6, the central chamber 34 and the first outer chamber are elastically deformed in the direction in which the packing 19 on the left side in the drawing contracts, that is, the inclined portion 28 moves away from the inner surface of the cylindrical portion 8 of the valve body 6. The sealing performance by the packing 19 between 33 is lowered. However, since the pressurized refrigerant from the compressor 4 is supplied into the second outer chamber 35, the piston body 7 moves toward the left side in the figure, and as shown in FIG. The piston body 7 is positioned at the left end of the cylindrical portion 8 of the valve body 6 in the figure, and the ball 22 on the left side of the figure closes the end 12a of the extraction pipe 12 as a valve seat. 21 connects the pipes 10a and 10b, and connects the pipes 10c and 10d in the valve body 6. Thus, when the piston body 7 moves from the right end of the valve body 6 toward the left end in the figure, the left packing 19 located on the front side in the moving direction toward the left side. The inclined portion 28 is pressed in the direction away from the inner surface of the cylindrical portion 8 of the valve body 6 (the direction of contraction) and elastically deforms.

  When the ball 22 on the left side in the drawing closes the end 12a of the extraction / exhaust pipe 12 serving as a valve seat, the flow of the refrigerant passing through the extraction / exhaust pipe 12 is blocked, and the refrigerant in the first outer chamber 33 and the central chamber As shown in FIG. 8, the inclined portion 28 of the packing 19 on the left side of the drawing is formed on the inner surface of the cylindrical portion 8 of the valve body 6 by the elastic restoring force of the leaf spring 20. Contact closely. Thus, in the state shown in FIG. 8, the refrigerant | coolant in the 1st outer chamber 33, the 2nd outer chamber 35, and the center chamber 34 is maintained at the high pressure.

  In the state shown in FIG. 8, when a voltage is applied to the electromagnet coil of the pilot valve 3, the pilot valve 3 draws high-pressure refrigerant from the discharge side of the compressor 4, the extraction pipe 37, the pilot The pressure is supplied to the first outer chamber 33 through the valve 3 and the extraction pipe 12, and the pressure in the second outer chamber 35 is discharged to the low pressure suction side of the compressor 4 through the extraction pipe 12, the pilot valve 3 and the exhaust pipe 36. Therefore, the pressure in the second outer chamber 35 decreases. Then, since the high-pressure refrigerant on the discharge side of the compressor 4 is always supplied into the central chamber 34, the central chamber is caused by the difference between the refrigerant pressure in the central chamber 34 and the refrigerant pressure in the second outer chamber 35. The pressurized refrigerant in 34 presses the inclined portion 28 of the packing 19 on the right side in the figure against the elastic restoring force of the leaf spring 20 in the direction away from the inner surface of the cylindrical portion 8 of the valve body 6.

  Then, as shown in FIG. 9, the central chamber 34 and the second outer chamber are elastically deformed in the direction in which the packing 19 on the right side in the drawing contracts, that is, the inclined portion 28 is separated from the inner surface of the cylindrical portion 8 of the valve body 6. The sealing performance by the packing 19 between 35 is lowered. However, since the pressurized refrigerant from the compressor 4 is supplied into the first outer chamber 33, the piston body 7 moves toward the right side in the figure, and as shown in FIG. The piston body 7 is positioned at the right end of the cylindrical portion 8 of the valve body 6 in the figure, and the right ball 22 in the figure closes the end 12a of the extraction pipe 12 as a valve seat. 21 connects the pipes 10b and 10c, and connects the pipes 10a and 10d in the valve body 6. Thus, when the piston body 7 moves from the left end of the valve body 6 toward the right end in the figure, the right packing 19 located on the front side in the moving direction toward the right side. The inclined portion 28 is pressed in the direction away from the inner surface of the cylindrical portion 8 of the valve body 6 (the direction of contraction) and elastically deforms.

  When the ball 22 on the right side in the figure closes the end 12a of the extraction / exhaust pipe 12 serving as a valve seat, the flow of the refrigerant passing through the extraction / exhaust pipe 12 is blocked, and the refrigerant in the second outer chamber 35 and the central chamber The refrigerant in the cylinder 34 has the same pressure as each other, and the inclined portion 28 of the packing 19 on the right side in the drawing contacts the inner surface of the cylindrical portion 8 of the valve body 6 by the elastic restoring force of the leaf spring 20. Thus, the refrigerant in the first outer chamber 33, the second outer chamber 35, and the central chamber 34 is maintained at a high pressure.

  The switching valve 2 operates as described above to reverse the refrigerant flow between the heat exchangers 5 and 5. Moreover, the switching valve 2 mentioned above accommodates the valve plate 11 in the cylindrical part 8, and brazes piping 10a, 10b, 10c to the said cylindrical part 8 and the valve plate 11 using the 1st melting | fusing point wax. . Then, the pipe 10d is brazed to the cylindrical portion 8 using a wax having a second melting point lower than the first melting point. Thereafter, the piston body 7 is accommodated in the cylindrical portion 8, end caps 9 are attached to both ends of the cylindrical portion 8 by welding, and the extraction pipe 12, the exhaust pipe 36, and the extraction pipe 37 are attached, The switching valve 2 is assembled.

  According to the present embodiment, the inclined portion 28 of the packing 19 is gradually inclined toward the inner surface of the cylindrical portion 8 of the valve body 6 as it approaches the end of the cylindrical portion 8 of the valve body 6. The inclined portion 28 of the packing 19 positioned on the front side in the moving direction of the piston body 7 is pressed in a contracting direction when the piston body 7 moves. For this reason, the front packing 19 does not hinder the movement of the piston body 7. Therefore, the piston body 7, that is, the valve body 21 can be moved smoothly, and the refrigerant flow among the pipes 10a, 10b, 10c, and 10d can be switched smoothly.

  Since both ends of the piston body 17 are provided with balls 22 as second valve bodies that close the ends 12a of the extraction exhaust pipe 12 as valve seats provided at both ends of the valve body 6, the piston body 7 However, the ball 22 is reliably positioned at a predetermined position where the end portion 12a of the extraction pipe 12 is blocked. For this reason, the valve body 21 can switch the flow between piping 10a, 10b, 10c, 10d reliably.

  Since the restricting member 18 that restricts the inclined portion 28 from being too far from the inner surface of the cylindrical portion 8 of the valve body 6 is provided, the inclined portion 28 can be prevented from being plastically deformed. Thus, since the inclined portion 28 can be prevented from being plastically deformed, the inclined portion 28, that is, the packing 19 can be prevented from being damaged.

  Further, in the conventional example described in the background art section, the packing 107 needs to have a sealing property to prevent the compressed discharge-side high-pressure refrigerant from flowing through the suction-side low pressure, and further, the packing 107 is pressed in a direction in which the packing 107 expands due to the pressure. Therefore, the seal portion of the packing 107 was damaged by repeated switching operations under a large load due to a pressure difference. In the above-described embodiment, the inclined portion 28 of the packing 19 is the cylindrical portion of the valve body 6. Since the angle gradually approaches the inner surface of the valve body 6 as it approaches the end of 8, the pressure difference applied to the inclined portion 28 of the packing 19 increases in the direction in which the inclined portion 28 of the packing 19 contracts. As a result, the sealing performance of the packing 19 decreases, so the pressure difference is reduced, and the load due to the pressure difference applied to the inclined portion 28 of the packing 19 is reduced. Durability of the packing 19 is improved.

  In the above-described embodiment, the sealing performance of the packing 19 is lowered in a state where the inclined portion 28 of the packing 19 is pressed in the contracting direction. At this time, the refrigerant flow from the packing 19 serves as the second valve body. The ball 22 seals.

  Since the air conditioner 1 includes the switching valve 2 described above, the piston body 7, that is, the valve body 21 of the switching valve 2 can be moved smoothly, and the refrigerant flows between the pipes 10a, 10b, 10c, and 10d. Can be smoothly switched.

  The above-described embodiment is particularly effective in the case of carbon dioxide having a higher working pressure than the chlorofluorocarbon refrigerant as the refrigerant (fluid), but a chlorofluorocarbon refrigerant may be used. Moreover, in this invention, you may use for apparatuses other than the air conditioner 1, and may switch the flow of various fluids. Further, in the present invention, if a plurality of pipes 10 are provided, any number may be provided (for example, only two pipes 10 may be provided). When only two pipes 10 are provided, the refrigerant flow between the pipes 10 is opened or shut off. Thus, in this invention, what is necessary is just to change the flow direction of a fluid, such as a refrigerant | coolant, or to open | release and interrupt | block the said flow, and to change the said flow. In the present invention, in addition to the ball 22, as shown in FIGS. 11A and 11B, the second valve body may be a member 40 having a flat surface made of, for example, a synthetic resin. In FIG. 11A and FIG. 11B, the same parts as those of the above-described embodiment are denoted by the same reference numerals and description thereof is omitted. In short, of course, in the present invention, the second valve body may have various configurations.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, various modifications can be made without departing from the scope of the present invention.

It is explanatory drawing which shows the structure of the air conditioner concerning one Embodiment of this invention. It is explanatory drawing which shows the state which the switching valve of the air conditioner shown by FIG. 1 switched the flow between piping. It is sectional drawing which expands and shows the III section in FIG. It is sectional drawing of the principal part of the piston body of the switching valve of the air conditioner shown by FIG.1 and FIG.2. FIG. 2 is an explanatory diagram schematically showing a state in which a voltage is applied to a coil of an electromagnet of a pilot valve of the air conditioner shown in FIG. It is explanatory drawing which shows typically the state which stopped the application to the coil of the electromagnet of the pilot valve of the air conditioner shown by FIG. It is explanatory drawing which shows typically the state which the piston body of the pilot valve of the air conditioner shown by FIG. 6 moved. It is explanatory drawing which shows typically the state which the packing of the piston body of the pilot valve of the air conditioner shown by FIG. 7 returned to the neutral state. It is explanatory drawing which shows typically the state which started applying a voltage to the coil of the electromagnet of the pilot valve of the air conditioner shown by FIG. It is explanatory drawing which shows typically the state which the piston body of the pilot valve of the air conditioner shown by FIG. 9 moved. (A) is sectional drawing which shows the principal part of the modification of the switching valve of the air conditioner shown by FIG. 1, (b) is sectional drawing which expands and shows the XIB part in Fig.11 (a). is there. It is sectional drawing which shows the structure of the switching valve used with the conventional air conditioner. It is sectional drawing of the principal part of the piston body of the switching valve of the air conditioner shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Switching valve 4 Compressor 5 Heat exchanger 6 Valve body 7 Piston body 10, 10a, 10b, 10c, 10d Piping 12a End (valve seat)
17 Piston body 18 Restriction member 19 Packing 21 Valve element 22 Ball (second valve element)
28 Inclined part 40 Member (second valve element)

Claims (4)

A tubular valve body with a plurality of pipes attached thereto;
A piston main body accommodated in the valve main body so as to be movable along the axis of the valve main body, a packing provided at both ends of the piston main body to contact the valve main body, and a central portion of the piston main body And a valve body that changes the flow between the plurality of pipes, and a piston body,
In the switching valve in which the valve body changes the flow between the plurality of pipes by moving the piston body along the axis of the valve body,
The switching valve, characterized in that the packing is formed in an annular shape, and has an inclined portion inclined in a direction of gradually approaching the inner surface of the valve body as its cross-sectional shape approaches the end of the valve body. At both end portions of the valve body, valve seats that communicate the inside and outside of the valve body are provided, and
The second valve body is provided at both end portions of the piston main body so as to come into close contact with the valve seat and close the valve seat when approaching the end portion of the valve main body. 1. The switching valve according to 1.   The switching member according to claim 1 or 2, wherein a restriction member for restricting the inclined portion of the packing from being too far from the inner surface of the valve body is attached to both ends of the piston body. valve. In a reversible cycle refrigeration apparatus comprising a compressor, a heat exchanger connected to the compressor, and a switching valve connected to the compressor and the heat exchanger,
A reversible cycle refrigeration apparatus comprising the switching valve according to any one of claims 1 to 3 as the switching valve.

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