JP6678227B2 - Flow path switching valve - Google Patents

Description

  The present invention relates to a slide-type flow path switching valve that performs flow path switching by moving a valve element, and particularly to a flow path switching valve suitable for performing flow path switching in a heat pump type cooling / heating system or the like.

  Generally, a heat pump type cooling / heating system such as a room air conditioner and a car air conditioner includes a flow path switching valve as flow path (flow direction) switching means in addition to a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expansion valve, and the like. It has.

  An example of a heat pump type cooling and heating system provided with this flow path switching valve will be briefly described with reference to FIG. In the illustrated heat pump type cooling and heating system 100, the operation mode (cooling operation and heating operation) is switched by a flow path switching valve (four-way switching valve) 140, and basically, the compressor 110 and the outdoor A heat exchanger 120, an indoor heat exchanger 130, and an expansion valve 160, and four ports between the compressor 110, the outdoor heat exchanger 120, the indoor heat exchanger 130, and the expansion valve 160; That is, the flow path switching valve 140 having the discharge side high pressure port D, the outdoor side inlet / outlet port C, the indoor side inlet / outlet port E, and the suction side low pressure port S is provided.

  The respective devices are connected by a flow path formed by a conduit (pipe) or the like. When the cooling operation mode is selected, as shown by a solid line arrow in FIG. The high-pressure port D is communicated with the outdoor-side inlet / outlet port C, and the indoor-side inlet / outlet port E is communicated with the suction-side low-pressure port S. Thereby, the refrigerant is sucked into the compressor 110, and the high-temperature and high-pressure refrigerant is guided from the compressor 110 to the outdoor heat exchanger 120 via the flow path switching valve 140, where it exchanges heat with outdoor air and condenses. Then, the refrigerant is introduced into the expansion valve 160 as a high-pressure two-phase refrigerant. The high-pressure refrigerant is decompressed by the expansion valve 160, and the depressurized low-pressure refrigerant is introduced into the indoor heat exchanger 130, where it exchanges heat with (cools) indoor air and evaporates. The low-temperature and low-pressure refrigerant is returned to the suction side of the compressor 110 via the flow path switching valve 140.

  On the other hand, when the heating operation mode is selected, the discharge-side high-pressure port D of the flow path switching valve 140 is connected to the indoor-side inlet / outlet port E, and the outdoor-side inlet / outlet port C is connected to, as indicated by a broken line arrow in FIG. The high-temperature and high-pressure refrigerant is led from the compressor 110 to the indoor heat exchanger 130, where the refrigerant exchanges heat with the indoor air (heats), condenses, and is condensed with the high-pressure two-phase refrigerant. And introduced into the expansion valve 160. The high-pressure refrigerant is depressurized by the expansion valve 160, and the depressurized low-pressure refrigerant is introduced into the outdoor heat exchanger 120, where it exchanges heat with outdoor air and evaporates. Is returned to the suction side of the compressor 110 via the flow path switching valve 140.

  As a four-way switching valve incorporated in the heat pump type cooling and heating system as described above, a four-way switching valve including a valve main body (main valve housing) containing a sliding main valve body and an electromagnetic pilot valve is conventionally known. (See, for example, Patent Document 1). In the slide type flow path switching valve described in Patent Document 1, a discharge side high pressure port D, an outdoor side inlet / outlet port C, a suction side low pressure port S, and an indoor side inlet / outlet port E are formed in a main valve housing. At the same time, the slide main valve body is slidably arranged in the left and right direction to create a communication state of the ports D → C and E → S or the ports D → E and C → S (to perform flow path switching). Are located. High-pressure refrigerant on the compressor discharge side and low-pressure refrigerant on the compressor suction side are selectively introduced to the left and right of the sliding main valve body through the pilot valve in the main valve housing. Two working chambers defined by a pair of left and right packing-equipped pistons are provided, and by utilizing the pressure difference between the two working chambers, the slide type main valve body is slid in the left-right direction to thereby control the flow. Road switching is performed.

JP 2009-41636 A

  In the conventional slide type flow path switching valve as described above, the high-pressure fluid (refrigerant) collides with the inner wall surface or the like in the main valve housing having a relatively small internal volume, and the flow direction thereof changes greatly. There is a dislike that the loss is large, and because the slide type main valve body with a pair of left and right packing pistons slides to switch the flow path, the sliding part is easily worn out by stick slip etc. Along with this, there is also a problem that the durability and the sealing performance of the sliding portion are deteriorated, and that the fluid (refrigerant) easily leaks from the sliding surface between the main valve housing and the sliding main valve body (the valve easily leaks). .

  In addition to the above, in the conventional flow path switching valve, in particular, in the four-way switching valve used in the above-mentioned heat pump type cooling and heating system, the state in which the high-temperature and high-pressure refrigerant and the low-temperature and low-pressure refrigerant are close to each other (thin wall) Since the air flows in a state of being separated from each other), the amount of heat exchange in the main valve housing becomes large, and there is also a problem that the efficiency of the system deteriorates.

  The present invention has been made in view of the above circumstances, and its object is to reduce pressure loss, reduce the amount of internal heat exchange as much as possible, and reduce the wear of sliding parts. It is an object of the present invention to provide a flow path switching valve which can be suppressed in terms of durability, can improve durability and sealing properties, and can be made less likely to leak.

In order to achieve the above object, a flow path switching valve according to the present invention is basically a cylindrical main valve whose upper and lower openings are hermetically sealed by an upper valve sheet and a lower valve sheet. A main valve having a valve housing, at least three ports provided in the upper valve seat and / or the lower valve seat in total, and a main valve body movably disposed in the main valve housing; A fluid pressure type actuator for moving the main valve body, wherein a communication passage for selectively communicating between the ports is provided in the main valve body, and the communication is performed by moving the main valve body. The upper valve seat and the lower valve seat both have a flat smooth surface to be sealed, and the surfaces to be sealed face each other. Placed and front Omobentai is a two-piece construction of the integral movable and vertically movable upper half and a lower half portion, U-shaped, each of the upper valve seat side and the lower valve seat side by the main valve body It is characterized in that a passage in the shape of a circle is formed .

  In a specific preferred aspect, at least one communication path that allows one of the ports to communicate with the other one is provided in the main valve body, and the main valve body is moved in one direction. Thereby, the flow path switching between the communicating ports is performed.

  A projecting portion having an annular sealing surface that is in close contact with an opening of each port in the upper valve seat and / or the lower valve seat is preferably protruded from both ends of the communication passage.

  In another preferred aspect, the actuator includes a reciprocating drive cylinder having a first working chamber and a second working chamber, each of which has a variable volume and is hermetically partitioned by a piston, into which high-pressure fluid in the main valve is introduced, A first step of moving the main valve body in one direction by introducing a high-pressure fluid into the first working chamber and discharging the high-pressure fluid from the second working chamber; And discharging the high-pressure fluid from the first working chamber to selectively take a second step of moving the main valve body in the other direction.

  In a further preferred aspect, a first cylinder having the first working chamber is provided on a front side of the main valve housing, and a second cylinder having the second working chamber is provided on a rear side of the main valve housing, A first pushing plate connected to a piston rod of the first cylinder is brought into contact with a front surface of the main valve body, and a second pushing plate connected to a piston rod of the second cylinder is provided on a rear surface of the main valve body. The push plate is brought into contact with the push plate.

  In a further preferred aspect, the first cylinder and the second cylinder have a common piston rod interconnecting the respective pistons, and the piston rod is provided with the first pushing plate and the second pushing plate. While being fixed, a portion of the piston rod between the first push plate and the second push plate is inserted into a front-rear through hole provided in the main valve body so as to be slightly vertically movable. .

  In another preferred aspect, the four-way pilot valve connected to the first working chamber and the second working chamber, and the high-pressure part and the low-pressure part of the main valve switches between the first stroke and the second stroke. To do so.

  In the flow path switching valve according to the present invention, since all ports are provided in the upper valve seat and the lower valve seat of the main valve housing, for example, two of four communication passages communicating between the ports are provided. The fluid from the start end to the end can be a straight passage having a diameter substantially equal to the diameter of each port, and the fluid can flow straight from the port directly below or directly above the port. ) Can be effectively suppressed from occurring. Also, by providing a guide portion of a specific shape at the bent portion (portion where the flow direction changes), the remaining communication passage can be made not to change the effective passage area from the start end to the end end so much, and the eddy at the bent portion. This makes it difficult to generate a flow, thereby suppressing expansion and contraction of the fluid in the communication passage and reducing resistance to the fluid flowing through the communication passage. As a result, the fluid can flow smoothly and the pressure loss can be reduced. , And the pressure loss can be considerably reduced as compared with the conventional flow path switching valve.

  Further, the main valve body receiving the high pressure is formed in a rectangular parallelepiped shape, and a communication passage formed of a straight through passage is provided therein, and a U-shaped communication passage is provided above and below the inside thereof, so that the entire structure is simple. In addition, the flow path switching balance can be improved, and sufficient strength and durability can be ensured.

  In addition, the surfaces to be sealed, that is, the upper valve sheet and the lower valve sheet, which are the parts where the main valve body (upper half and lower half) are in sliding contact when switching the flow path, are flat, The surface to be sealed can be made a flat and smooth surface (the surface accuracy can be easily increased), and thus the sealing performance can be significantly improved.

  Further, since all the ports are provided in the upper valve seat and the lower valve seat of the main valve housing, the piping can be easily arranged, and the substantial occupied space including the piping can be reduced.

  In addition, the main valve body is divided into two parts, an upper half and a lower half, so that the upper half and the lower half can be moved up and down independently of each other, and between the upper half and the lower half. The upper half and the lower half can be pressed against the valve seat surface by the urging force of the urging means such as a compression coil spring. In addition, by projecting a convex portion on the main valve body side (both ends of each communication passage) and forming an end surface thereof as an annular sealing surface, the area of a portion in contact with the valve seat surface can be minimized. The contact pressure can be increased. As a result, sufficient sealing properties can be ensured, and valve leakage can be more effectively suppressed.

  In addition to the above, when the flow path switching valve according to the present invention is used in an environment in which a high-temperature and high-pressure refrigerant and a low-temperature and low-pressure refrigerant flow, such as a heat pump cooling and heating system, each communication path is relatively large in the main valve body. Since it is provided at a distance, the amount of heat exchange in the main valve housing is higher than that of the conventional case where the high-temperature and high-pressure refrigerant and the low-temperature and low-pressure refrigerant flow close to each other (a state where one thin wall is separated). Can be greatly reduced, and the effect that the efficiency of the system can be improved can also be obtained.

  In addition, since the actuator employs a fluid pressure type in which the main valve is reciprocated by utilizing a pressure difference between a high-pressure fluid and a low-pressure fluid supplied into the main valve, the main valve is electromagnetically or electrically driven. As compared with the case where the actuator is directly moved by the actuator, cost reduction, power consumption reduction, energy saving, and the like can be achieved.

  Problems, configurations, and operational effects other than those described above will be clarified by the following embodiments.

FIG. 3 is a top view showing a state in which the main valve body is at a first moving position in one embodiment of the flow path switching valve according to the present invention. FIG. 4 is a top view showing a state where the main valve body is at a second movement position in one embodiment of the flow path switching valve according to the present invention. FIG. 2 is a sectional view taken along the line AA of FIG. 1. Sectional drawing according to the AA arrow line of FIG. FIG. 4 is a sectional view taken along line BB of FIG. 3. FIG. 5 is a sectional view taken along line BB of FIG. 4. FIG. 2 is a sectional view taken along the line CC of FIG. 1. (A) is a partial sectional view taken along line DD in FIG. 3, and (B) is a partial sectional view taken along line EE in (A). FIG. 4 is an enlarged cross-sectional view for explaining the configuration and operation of a seal surface separation mechanism provided in the flow path switching valve of the embodiment. FIG. 3 is a partially cutaway top view showing the flow path switching valve of the embodiment together with an example of a four-way pilot valve provided in an actuator provided therein. The front view which shows the flow-path switching valve of the said Example with an example of the four-way pilot valve provided in the actuator provided in it. 11A and 11B are enlarged cross-sectional views showing the four-way pilot valve shown in FIG. 10, wherein FIG. The schematic block diagram which shows an example of a heat pump type cooling and heating system.

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

  FIG. 1 is a top view showing a state in which a main valve body is at a first movement position in one embodiment of a flow path switching valve according to the present invention. FIG. FIG. 5 is a top view showing a state at a movement position. 3 and 4 are cross-sectional views taken along line AA of FIGS. 1 and 2, respectively, and FIGS. 5 and 6 are cross-sectional views taken along line BB of FIGS. 3 and 4, respectively.

  In this specification, descriptions indicating positions and directions such as up and down, left and right, front and back, etc. are provided for convenience according to the drawings in order to avoid complicating the description, and are actually incorporated in a heat pump type cooling / heating system or the like. It does not necessarily indicate the position and direction in the closed state.

  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 illustrated embodiment is a slide type four-way switching valve, and is used as, for example, the four-way switching valve 140 in the heat pump type cooling / heating system 100 shown in FIG. A reciprocating drive cylinder 50 having a main valve 5 having a main valve body 20 disposed in the main valve housing 10 so as to be capable of reciprocating linear movement in the front-rear direction (hereinafter, sometimes abbreviated as back-and-forth movement) and moving up and down. And a hydraulic actuator 7 having a four-way pilot valve 80 (see FIGS. 10 and 11 described later).

  The main valve housing 10 of the main valve 5 is made of a metal material such as aluminum or stainless steel by die molding (aluminum die casting or the like), and has a rectangular parallelepiped box-shaped portion 10C with an open front surface. A thick rectangular plate-shaped front lid member 10D that is caulked and fixed so as to hermetically seal the front opening of the box-shaped portion 10C and hermetically joined by soldering, brazing, welding, or the like. The upper surface and the lower surface of the box-shaped portion 10C are an upper valve seat 10A and a lower valve seat 10B, respectively. The lower surface of the upper valve seat 10A and the upper surface of the lower valve seat 10B are flat and smooth valve seat surfaces 17. , 17.

  A first port 11 and a second port 12 made of a pipe joint are vertically provided on the left and right sides of the upper valve seat 10A with a predetermined space J therebetween, and the pipes are provided on the left and right sides of the lower valve seat 10B with a predetermined space J therebetween. A third port 13 and a fourth port 14 made of a joint are vertically provided. Here, the first port 11, the third port 13, and the second port 12 and the fourth port 14 are arranged at the same position in plan view.

  In this embodiment, for example, when incorporated in a heat pump type cooling / heating system 100 as shown in FIG. 13, the first port 11 is a discharge-side high pressure port D connected to the compressor discharge side, and the second port 11 is a second port. Reference numeral 12 denotes an indoor entrance / exit port E connected to the indoor heat exchanger, third port 13 denotes an outdoor entrance / exit port C connected to the outdoor heat exchanger, and fourth port 14 connects to the compressor suction side. The suction side low pressure port S is used.

  Near the left and right ends of the upper valve seat 10A and the lower valve seat 10B in the main valve housing 10, a pair of left and right rails 44, 44 are provided on the rail surface (for convenience in moving the main valve body 20 back and forth, respectively). The main valve body contact surface) is laid in parallel with the valve seat surface 17 in the front-rear direction in a state of being flush with the valve seat surface 17 (details will be described later).

  The main valve element 20 disposed in the main valve housing 10 has a two-part configuration including a short prismatic upper half 20A and a lower half 20B. More specifically, the upper half portion 20A is composed of a relatively thick first layer member 21 and a second layer member 22 integrally joined to the lower surface side of the first layer member 21 by welding or the like. The lower half portion 20B is composed of the layer member 23 and the relatively thick fourth layer member 24 integrally joined to the lower surface side of the third layer member 23 by welding or the like.

  As shown in FIG. 8, between the upper half 20A (the second layer member 22) and the lower half 20B (the third layer member 23), they are urged away from each other. Four compression coil springs 29 as biasing means are contracted. The four compression coil springs 29 are loaded in four spring storage holes 23h provided near the four corners on the upper surface side of the third layer member 23 with a part thereof projecting upward.

  In switching the flow path, the main valve body 20 is reciprocated in the front-rear direction by an actuator 7 described later, and moves from the first movement position as shown in FIGS. 1 and 5 to the rear from the first movement position. And a second movement position as shown in FIGS. 2 and 6, which is moved by a predetermined distance L (see FIGS. 1 and 2) toward.

  When the main valve body 20 is in the first movement position, a first linear communication path 31 that connects the first port 11 and the third port 13 and a second linear port 12 that communicates with the fourth port 14 are connected. And a U-shaped third communication path 33 and a third port for communicating the first port 11 and the second port 12 when the second movement position is taken. There is provided a U-shaped fourth communication path 34 for communicating the port 13 with the fourth port 14 (details will be described later).

  On the other hand, a first cylinder 50A and a second cylinder 50B constituting the reciprocating drive cylinder 50 are provided on the front side of (the front lid member 10D of) the main valve housing 10 and the rear side of the box-shaped portion 10C along the front-rear direction. Each is protruding.

  The first cylinder 50A has a cylinder portion 51 provided so as to straddle (a thickness portion of) the front lid member 10D and a front protruding portion. In the cylinder portion 51, a piston 52 with a packing 53 is provided in the front-rear direction. A variable-volume first working chamber 55A is formed which is slidably fitted and hermetically sealed by the piston 52 with the packing 53.

  The second cylinder 50B has a cylinder portion 51 provided on a rearward projecting portion of the main valve housing 10, and a piston 52 with a packing 53 is inserted into the cylinder portion 51 so as to be slidable in the front-rear direction. A second working chamber 55B having a variable capacity is hermetically sealed by the piston 52 with the packing 53.

  The first cylinder 50 </ b> A and the second cylinder 50 </ b> B have a common piston rod 54 that interconnects the respective pistons 52, 52. A first rectangular pressing plate 58A, which is brought into contact with the front surface, is fixed, and a second pressing plate, which comes into contact with the rear surface of the main valve body 20, is provided near the rear end of the middle portion thereof. The plate 58B is fixed. The first pushing plate 58A and the second pushing plate 58B are large enough to press substantially the entire front and rear surfaces of the main valve body 20.

  Further, a portion between the first pushing plate 58A and the second pushing plate 58B of the piston rod 54 is formed in a substantially central portion (the third layer member 23) of the main valve body 20 before and after an oval cross section. It is inserted into the through hole 60 so that it can move up and down slightly.

  The first push plate 58A and the second push plate 58B are fixed to the piston rod 54, for example, as shown in FIG. 7 in addition to FIG. 5 and FIG. A slit-shaped notch 61 whose lower surface is opened below the center of the 58A and the second pushing plate 58B is formed, and a pair of right and left fitting grooves 62 are formed in the piston rod 54 by parallel chamfering on both left and right sides. The left and right edges of the slit-shaped notch 61 are pressed into the fitting groove 62 from above by press-fitting until the upper end thereof comes into contact with the piston rod 54, and then fixed by welding or the like as necessary. You.

  The first working chamber 55A of the first cylinder 50A is provided with a first inlet / outlet port 56A for introducing / discharging a high-pressure fluid to / from the first working chamber 55A, and the second working chamber of the second cylinder 50B. 55B is provided with a second inlet / outlet port 56B for introducing / discharging the high-pressure fluid into / from the second working chamber 55B. The first inlet / outlet port 56 </ b> A and the second inlet / outlet port 56 </ b> B are open to a portion (left side) near the protruding end of the cylinder portion 51.

  Here, the main valve body 20 is in a state where the first pushing plate 58A is in the first movement position where the first pushing plate 58A is in contact with the front lid member 10D and the movement thereof is prevented (FIGS. 1 and 5). The state in which the second pushing plate 58B is in the second movement position where the rearward movement is prevented by contacting the rear wall 10E of the box-shaped portion 10C (FIGS. 2 and 6) is selectively taken. Are getting to get.

  In other words, the front lid member 10D and the rear wall 10E serve as a stopper for stopping the forward and backward movement of the main valve body 20, and the first push when the main valve body 20 is at the second movement position (FIG. 2). The distance between the moving plate 58A and the front lid member 10D and the distance between the second pushing plate 58B and the rear wall 10E of the box-shaped portion 10C when the main valve body 20 is at the first moving position (FIG. 1). Are both L. Therefore, the moving distance of the main valve body 20 from the first moving position to the second moving position and the moving distance from the second moving position to the first moving position are both L. It is said.

  In a state where the main valve body 20 is in the first movement position (FIGS. 1 and 5), high-pressure fluid is introduced into the first working chamber 55A through the first inlet / outlet port 56A, and the second working chamber 55B is moved from the second working chamber 55B to the second working chamber 55B. When the high-pressure fluid is discharged through the second inlet / outlet port 56B, the pistons 52, 52 of the first cylinder 50A and the second cylinder 50B move rearward, and accordingly, the main valve body 20 is moved by the first pushing plate 58A. The second pushing plate 58B abuts on the rear wall 10E of the box-shaped portion 10C and is prevented from moving rearward. The moving distance at this time is L, and the position at this time is a second moving position (moving from the first moving position to the second moving position is referred to as a backward moving stroke).

  On the other hand, when the main valve body 20 is in the second movement position (FIGS. 2 and 6), high-pressure fluid is introduced into the second working chamber 55B via the second inlet / outlet port 56B, and the first working chamber 55B is introduced. When the high-pressure fluid is discharged from 55A through the first inlet / outlet port 56A, the pistons 52, 52 of the first cylinder 50A and the second cylinder 50B move forward, and accordingly, the main valve body 20 is moved by the second pushing plate 58B. Is pushed forward from the second movement position, and the first pushing plate 58A comes into contact with the front lid member 10D and is prevented from moving forward. The moving distance at this time is set to L, and the position at this time is set as a first moving position (movement from the second moving position to the first moving position is referred to as a forward moving stroke).

  Next, the configuration of the main valve body 20 and the first to fourth communication passages 31 to 34 provided therein will be described in detail.

  The upper surface opening and / or the lower surface opening of each of the passage portions provided in the first to fourth layer members 21 to 24 constituting the first to fourth communication passages 31 to 34 are formed by the first to fourth ports 11 to 14. Are disposed at the same position in plan view as any one of the two, and the diameter thereof is substantially the same as the diameter of each of the ports 11 to 14. Further, the effective passage area (passage diameter) of each passage portion Also, the entire length is substantially the same as the diameter of each port 11 to 14.

  The first layer member 21 forming the upper part of the upper half portion 20A of the main valve body 20 has two straight through holes with a predetermined space J (same as the space between the first port 11 and the second port 12) on the left and right. Road portions 21A and 21B are provided, and two lateral hole-equipped passage portions 21C and 21D connected by linear lateral holes 21E that are linear in a plan view and whose lower surface openings are closed by the second layer member 22 are provided. The passage portions 21C and 21D with lateral holes are arranged at a predetermined interval J on the left and right, and form a U-shaped third communication passage 33 by combining them. The configuration, operation, and effect of the third communication path 33 will be described later in detail. The separation distance between the straight through passage portions 21A, 21B and the passage portions 21C, 21D with lateral holes is set equal to the movement distance L of the main valve body 20 from the first movement position to the second movement position described above. .

  Therefore, when the main valve body 20 is in the first movement position, the straight through-path portions 21A and 21B are located directly below the first port 11 and the second port 12, and the main valve body 20 is moved from the first movement position. When the main valve body 20 is moved rearward by the distance L, the main valve body 20 moves to the second movement position, the upper surface openings of the straight through-passage portions 21A and 21B are closed by the upper valve seat 10A, and the passage portions 21C with side holes are provided. The upper opening of 21D is located immediately below the first port 11 and the second port 12.

  Conversely, when the main valve body 20 is moved forward by a distance L from the second movement position, the main valve body 20 moves to the first movement position, and the upper surface openings of the passage portions 21C and 21D with side holes are closed. While being closed by the upper valve seat 10A, the upper surface openings of the straight through passage portions 21A and 21B are located immediately below the first port 11 and the second port 12.

  The second layer member 22 that constitutes the lower part of the upper half portion 20A of the main valve body 20 has two straight through-path portions 22A so as to be located directly below the straight-through portions 21A and 21B of the first layer member 21, 22B is provided.

  In addition, the third layer member 23 constituting the upper part of the lower half portion 20B of the main valve body 20 has two straight through-path portions so as to be located immediately below the straight through-port portions 22A and 22B of the second layer member 22. 23A and 23B are provided.

  Similarly to the first layer member 21, the fourth layer member 24 constituting the lower part of the lower half portion 20B of the main valve body 20 is provided with two straight through-path portions 24A and 24B at a predetermined interval J on the left and right. In addition, there are provided two passage portions 24C and 24D with lateral holes connected by linear lateral holes 24E that are linear in plan view and whose upper surface opening is closed by the third layer member 23. The passage portions 24C and 24D with the lateral holes are arranged at a predetermined interval J on the left and right, and together form a U-shaped fourth communication passage 34. The separation distance between the straight through passage portions 24A, 24B and the passage portions 24C, 24D with side holes is set equal to the movement distance L of the main valve body 20 from the above-described first movement position to the second movement position. .

  Therefore, when the main valve body 20 is at the first movement position, the straight through-path portions 24A and 24B are located directly above the third port 13 and the fourth port 14, and the main valve body 20 is moved to the first movement position. When the main valve body 20 is moved rearward by a predetermined distance L from the main valve body 20, the main valve body 20 moves to the second movement position, the lower surface openings of the straight through passage portions 24A and 24B are closed by the lower valve seat 10B, and the passage with the lateral hole is provided. The lower surface openings of the portions 24C and 24D are located immediately above the third port 13 and the fourth port 14.

  Conversely, when the main valve body 20 is moved forward by a distance L from the second movement position, the main valve body 20 moves to the first movement position, and the lower surface openings of the passage portions 24C and 24D with the side holes are closed. While being closed by the lower valve seat 10B, the lower surface openings of the straight through passage portions 24A and 24B are located directly above the third port 13 and the fourth port 14.

  As shown in FIGS. 3 and 4, the ports 11 on the valve seat surfaces 17 and 17 of the upper valve seat 10A and the lower valve seat 10B are provided at both ends of the communication passages 31, 32, 33 and 34, respectively. Projections 36 having an annular sealing surface closely contacting the openings 14 to 14 are provided.

  Further, as shown in FIG. 3, the first communication passage 31 and the second communication passage 32 are divided communication passages extending over the upper half 20A and the lower half 20B of the main valve body 20. The following measures have been taken to ensure the sealing performance. That is, as a representative description of the first communication passage 31, a stepped large-diameter portion 22c is formed below the straight through-passage portion 22A of the second layer member 22 constituting the first communication passage 31, A cylindrical portion 23c slidably inserted into the large-diameter portion 22c extends at the upper end of the straight through-passage portion 23A of the third layer member 23, and is provided between the large-diameter portion 22c and the cylindrical portion 23c. An O-ring 28 is interposed, and a washer 27 is fixed to the lower end of the large-diameter portion 22c by welding or the like in order to prevent the O-ring 28 from falling off. The second communication passage 32 has the same configuration.

  In addition to the above, in the present embodiment, the main valve element 20 is disposed between the first layer member 21 of the main valve element 20 and the upper valve seat 10A and between the fourth layer member 24 and the lower valve sheet 10B. A ball-type sealing surface separation mechanism 45 is provided for separating the sealing surface on the main valve body 20 side from the valve seat surface 17 of the upper valve seat 10A and the lower valve seat 10B during the movement.

  As shown in a representative example in FIG. 9, the ball-type sealing surface separation mechanism 45 is provided between the first layer member 21 and the upper valve seat 10 </ b> A. A housing part 47 that houses a part of the main valve body 20 protruding vertically and rotatably and substantially prevented from moving, and a main valve before and at the end of movement of the main valve body 20. A part of the ball 46 protruding from the housing portion 47 is fitted so that the sealing surface 37 on the body 20 side does not separate from the valve seat surface 17 of the upper valve seat 10A. At the time of the start of the road switching), there is provided a truncated conical hole 48 shaped so that the ball 46 rolls out while pushing down the main valve body 20. The concave hole 48 is formed in the rail 44 laid on the upper valve seat 10A, and the accommodating portion 47 is fixed to the round hole 47a and the round hole 47a by press fitting or the like, and the upper portion is narrowed. And a tubular stopper metal fitting 47b.

  The accommodation portion 47 in which the ball 46 is accommodated moves the main valve body 20 in the front-rear direction at the same position near the four corners of the first layer member 21 and the fourth layer member 24 of the main valve body 20 in plan view. The concave hole 48 is provided at a distance twice as long as the distance L, and the concave portion 48 is provided in the accommodation portion of the left and right rails 44, 44 laid on the upper valve seat 10A and the lower valve seat 10B in plan view. A total of four positions are provided at the same position as the position 47 and at a position separated from the position by the moving distance L (see FIGS. 1 and 2).

  The rail 44 is not always necessary, and the concave hole 48 may be provided directly in the upper valve seat 10A and the lower valve seat 10B. In this embodiment, the rails 44 provided with the concave holes 48 at four locations as described above are prepared in advance, and a long groove into which the rails 44 are embedded is formed when the box-shaped portion 10C is molded. The long groove forming portion of the mold should be able to be pulled out forward after molding), a method of fitting and fixing the rail 44 with the concave hole 48 into the long groove after molding, or a mold of the box-shaped portion 10C. A technique of insert-molding the rails 44 with the concave holes 48 and integrating them together with the molding is adopted.

  In the above-mentioned ball-type seal surface separation mechanism 45, before the movement of the main valve body 20 and at the end of the movement, as shown in FIG. 9A, the ball 46 is inserted into the concave hole 48 of the upper valve seat 10A. Some are stuck. This fitted amount (height from the valve seat surface 17 of the upper valve seat 10A to the top of the ball 46) is defined as h. When the main valve body 20 starts to move from this state, the accommodating portion 47 also starts to move, and accordingly, the ball 46 moves, as shown in FIG. 9B, to the main valve body 20 (upper half 20A). Rolls out of the concave hole 48 while being pressed down against the urging force of the compression coil spring 29 compressed between the upper half 20A and the lower half 20B. Thereby, the sealing surface 37 of the main valve body 20 is separated from the valve seat surface 17 of the upper valve seat 10A. At this time, the amount of depression of the main valve body 20 is the fitting amount h.

  When the main valve body 20 moves by the distance L, the ball 46 fits into the next concave hole 48, so that the main valve body 20 (upper half 20A) is pushed up by the urging force of the compression coil spring 29, and The sealing surface 37 of the body 20 is pressed against the valve seat surface 17 of the upper valve seat 10A.

  As understood from the above description, when the main valve body 20 assumes the first movement position, the first communication passage 31 that allows the first port 11 and the third port 13 to communicate with each other includes the straight through passage portion 21A, The second communication passage 32 that makes the second port 12 and the fourth port 14 communicate with each other is a straight passage constituted by 22A, 23A, and 24A, and is formed by the straight through passage portions 21B, 22B, 23B, and 24B. It becomes a configured linear passage.

  On the other hand, when the main valve body 20 assumes the second movement position, the third communication passage 33 for communicating the first port 11 with the second port 12 is provided in the upper half portion 20A of the main valve body 20. A U-shaped passage composed of passage portions 21C and 21D with side holes is provided, and a fourth communication passage 34 for communicating the third port 13 and the fourth port 14 is provided in the lower half portion 20B of the main valve body 20. It becomes a U-shaped passage composed of the passage portions 24C and 24D provided with the lateral holes.

  Here, as shown in FIG. 4, between the passage portions 21C and 21D with the lateral holes forming the third communication passage 33 and between the passage portions 24C and 24D with the lateral holes forming the fourth communication passage 34, the lateral holes are formed. A relatively long guide portion 20G in the left-right direction is provided, which bulges toward the sides 21E and 24E and has a rounded inner end side corner. By the guide portion 20G, the generation of eddy flow in the portion where the fluid (refrigerant) bends in a U-shape can be suppressed, and the effective passage area (passage diameter) of the lateral holes 21E and 24E and the diameter of each of the ports 11 to 14 are determined. Are substantially the same, the diameters of the third communication passage 33 and the fourth communication passage 34 are substantially constant over the entire length, whereby the expansion of the fluid in the third communication passage 33 and the fourth communication passage 34 Shrinkage does not occur, so that pressure loss can be reduced.

  It is assumed that the upper half 20A (third communication path 33) of the main valve body 20 is composed of two members, the first layer member 21 and the second layer member 22, and the lower half 20B (the fourth communication path) of the main valve body 20. 34) is not formed of the third layer member 23 and the fourth layer member 24, but the upper half 20A and the lower half 20B are respectively formed as one body by die molding. Since the side holes 21E and 24E of the communication passage 33 and the fourth communication passage 34 constitute an undercut portion, the third communication passage 33 and the fourth communication passage 34 have to be formed into a bowl shape without the guide portion 20G. As a result, the generation of eddy flow cannot be suppressed, and the passage diameter cannot be made substantially constant, so that the pressure loss increases.

  As described above, in the flow path switching valve 1 of the present embodiment, by performing the backward movement process of moving the main valve body 20 backward from the first movement position by the distance L, the first communication passage 31 Between the ports 11 and 13 communicating with each other and between the ports 12 and 14 communicating with the second communication path 32, between the ports 11 and 12 communicating with the third communication path 33 and between the ports 13 and 14 communicating with the fourth communication path 34. By performing a forward movement step of moving the main valve body 20 forward from the second movement position by a distance L by switching the flow path to the port 11-12, the third communication path 33 allows communication between the ports 11-12. The flow path is switched from between the ports 13 and 14 communicating with the fourth communication path 34 to the ports 11 and 13 communicating with the first communication path 31 and between the ports 12 and 14 communicating with the second communication path 32. That.

  When the flow path switching valve 1 of the present embodiment is incorporated into a heat pump type cooling and heating system as shown in FIG. 13, for example, as described above, the first port 11 is connected to the discharge side connected to the compressor discharge side. The high pressure port D, the second port 12 is an indoor entrance / exit port E connected to an indoor heat exchanger, the third port 13 is an outdoor entrance / exit port C connected to an outdoor heat exchanger, and the fourth port 14 is a compressor suction. It is a suction side low pressure port S connected to the side.

  Then, when performing the cooling operation, the main valve body 20 is set to the first movement position. As a result, as indicated by the white arrow in FIG. 3, the high-pressure refrigerant from the compressor flows to the discharge-side high-pressure port 11 (D) → the first linear communication passage 31 → the outdoor-side inlet / outlet port 13 (C). At the same time, the low-pressure refrigerant from the indoor heat exchanger flows from the indoor-side inlet / outlet port 12 (E) to the linear second communication path 32 to the suction-side low-pressure port 14 (S).

  On the other hand, when performing the heating operation, the main valve body 20 is moved backward from the first movement position to take the second movement position. Thereby, the flow path is switched, and the high-pressure refrigerant from the compressor is discharged from the discharge-side high-pressure port 11 (D) → the U-shaped third communication path 33 → the indoor side as shown by the white arrow in FIG. While flowing to the inlet / outlet port 12 (E), the low-pressure refrigerant from the outdoor heat exchanger flows to the outdoor-side inlet / outlet port 13 (C) → the inverted U-shaped fourth communication passage 34 → the suction side low pressure port 14 (S). And flows.

  In the flow path switching valve 1 of the present embodiment having such a configuration, the first communication path 31 and the second communication path 32 have a thickness (passage diameter) from the start end to the end end of the first port 11 and the second port. Since the refrigerant has a straight path substantially the same as the diameter of the port 12 and the refrigerant flows straight down from the first port 11 and the second port 12 directly, the pressure loss in the main valve 5 (main valve body 20) is reduced. It can be suppressed effectively.

  Further, since the U-shaped third communication passage 33 and the fourth communication passage 34 are provided with the guide portion 20G having a specific shape as described above, the effective passage area can be prevented from changing so much from the start end to the end. A vortex in the U-shaped bent portion can be hardly generated, whereby the expansion and contraction of the fluid in the communication passages 33 and 34 is suppressed, and the resistance to the fluid flowing in the communication passages 33 and 34 is reduced, As a result, the fluid can flow smoothly and the pressure loss can be reduced, and the pressure loss can be considerably reduced in total as compared with the conventional flow path switching valve.

  Further, the main valve body 20 receiving the high pressure is formed in a rectangular parallelepiped shape, and communication passages 31 and 32 formed of straight through paths are provided therein, and U-shaped communication passages 33 and 34 are provided above and below the inside. Therefore, the overall structure can be simplified, the flow path switching balance can be improved, and sufficient strength and durability can be ensured.

  In addition, the surfaces to be sealed, that is, the upper valve seat 10A and the lower valve seat 10B, which are the parts where the main valve body 20 (the upper half 20A and the lower half 20B) are in sliding contact at the time of switching the flow path, are flat. Therefore, the surface to be sealed can be made a flat and smooth surface (the surface accuracy can be easily increased), whereby the sealing performance can be remarkably improved.

  Further, since all the ports 11 to 14 are provided in the upper valve seat 10A and the lower valve seat 10B of the main valve housing 10, the piping can be easily arranged and the substantial occupied space including the piping can be reduced. it can.

  The main valve body 20 is divided into two parts, an upper half 20A and a lower half 20B, so that the upper half 20A and the lower half 20B can be independently moved up and down. Since the compression coil spring 29 is compressed between the portion 20A and the lower half portion 20B, the upper half portion 20A is pushed up by the spring force, and the sealing surface thereof is formed on the valve seat surface 17 of the upper valve seat 10A. While being pressed around the ports 11 and 12, the lower half 20B is pushed down and its sealing surface is pressed around the ports 13 and 14 on the valve seat surface 17 of the lower valve seat 10B.

  In this case, since the convex portion 36 is protruded from the main valve body 20 (the upper half portion 20A and the lower half portion 20B) and the end surface thereof is the annular sealing surface 37, the portion in contact with the valve seat surface 17 is provided. Is minimized, so that the contact pressure is increased. Due to these synergistic effects, sufficient sealing properties can be ensured, and valve leakage can be effectively suppressed.

  In addition, in the present embodiment, the upper half portion 20A of the main valve body 20 is pushed down by the ball-type seal surface separation mechanism 45 when the main valve body 20 is moved (during switching of the flow path), and Since the half portion 20B is pushed up so that the sealing surface on the main valve body 20 side is separated from the valve seat surfaces 17, 17 of the upper valve seat 10A and the lower valve seat 10B, almost no sliding friction occurs. Therefore, stick-slip or the like can be hardly generated, and abrasion of a sliding portion can be largely suppressed. Further, since abrasion is suppressed, sealing performance is improved and valve leakage can be more effectively suppressed.

  Further, in a conventional four-way switching valve having a sliding main valve element as disclosed in Patent Document 1, since the flow passage opening area between the high-pressure pipe D and the low-pressure pipe S changes rapidly when the flow paths are switched, Abnormal noise (switching noise) is generated when the high-pressure refrigerant gets into the low-pressure pipe. In order to prevent this noise, the frequency of the compressor is gradually lowered on the cooling and heating system side so that the noise caused by the pressure difference between the high-pressure pipe D and the low-pressure pipe S becomes an acceptable differential pressure. , It was necessary to switch the flow path. In the flow path switching valve 1 of the present embodiment, since the main valve body is floated from the valve seat surface by the amount of fitting h by the ball-type sealing surface isolation mechanism 45 and then switched, a fixed flow path opening area is obtained immediately after the switching. Can be secured, and the opening area of the flow passage between the high-pressure pipe D and the low-pressure pipe S does not suddenly change, so that the generation of the abnormal noise can be suppressed. Further, by appropriately changing the fitting amount h, the degree of decrease in the frequency of the compressor at the time of switching the flow path can be made smaller than that of the cooling / heating system using the four-way switching valve of Patent Document 1, and the frequency of the compressor can be reduced. It is also possible to switch the flow path without lowering the flow rate.

  In addition to the above, when the flow path switching valve 1 of the present embodiment is used in an environment in which a high-temperature and high-pressure refrigerant and a low-temperature and low-pressure refrigerant flow, such as a heat pump cooling and heating system, each of the communication passages 31 to 34 has a main valve body. 20 are relatively spaced apart from each other, so that a high-temperature and high-pressure refrigerant and a low-temperature and low-pressure refrigerant flow closer to each other (a state in which one thin wall is separated). The amount of heat exchange in the valve housing 10 can be greatly reduced, so that the effect of improving the efficiency of the system can be obtained.

  In the above embodiment, the upper half 20A of the first layer member 21 and the second layer member 22 joined to the first layer member 21, and the third layer member 23 and the fourth layer member 24 joined thereto are combined. Although the lower half 20B was configured in place of the above, the upper half 20A and the lower half 20B may be integrally formed from the beginning by a 3D printer or the like, respectively, and further, the upper half 20A and The lower half 20 </ b> B may be made as an integral body, that is, the main valve body 20 may be made as one member.

  Further, in the above embodiment, the four-way switching valve 1 has been exemplified, but the flow path switching valve according to the present invention is not limited to the four-way switching valve, but can be applied to a three-way switching valve or the like. In the case of a three-way switching valve, in the flow path switching valve (four-way switching valve) 1 of the above embodiment, for example, the upper half portion 20A is manufactured as an integral body from the beginning (there is no need to form a U-shaped communication passage). Therefore, the second port 12 provided in the main valve housing 10 is eliminated, and the straight through-passage portions 21B, 22B, 23B, 24B constituting the second communication passage 32 and the third communication passage 33 and the passage portion with the lateral hole are provided. 21C, 21D and the parts attached thereto are deleted, and the communication path is a linear first communication path that allows the first port 11 to communicate with the third port 13 when the main valve body 20 assumes the first movement position. When the main valve element 20 takes the second movement position, the U-shaped fourth communication path 34 that connects the third port 13 and the fourth port 14 may be used.

  When the three-way switching valve is used in the above-described heat pump cooling and heating system, two three-way switching valves are used to operate as a four-way switching valve, or a refrigerant or a cold / hot air supply destination is switched (for example, Switching between sending to one of the two rooms or sending to the other).

  Next, the configuration and operation of the four-way pilot valve 80 provided in the actuator 7 having the first and second cylinders 50A and 50B will be described with reference to FIGS.

  In the present embodiment, the flow path switching, that is, the switching between the backward moving stroke and the forward moving stroke, is performed by the first inlet / outlet port 56A and the second inlet / outlet port 56B in the first and second cylinders 50A and 50B, and The first port 11 (the high pressure port D on the discharge side, sometimes referred to as the high pressure port 11) which is the high pressure portion of the valve 5 and the fourth port 14 (the low pressure port S which is the low pressure port S on the suction side) which is the low pressure portion ) May be performed by an electromagnetic four-way pilot valve 80 connected to the solenoid valve.

  The four-way pilot valve 80 is mounted horizontally on the rear portion of the left side surface of the box-shaped portion 10C of the main valve housing 10 via a U-shaped base end fitting 65 and a receiving end fitting 66 (mounting). Details of the tools 65, 66, etc. will be described later).

  The structure of the four-way pilot valve 80 is well known, and as shown in FIG. 12 (in FIG. 12, the vertical direction and the front-back direction are different from those of the other drawings), a coil 82 a for energizing excitation A cover case 82b that covers the outer periphery of the coil 82a, a suction element 84 disposed on the inner circumference side of the coil 82a and fixed to the cover case 82b with bolts 82c, a plunger 85 disposed opposite to the suction element 84, and the like are provided. ing. The plunger 85 is slidably fitted into a cylindrical guide pipe 86 in which one end (the upper end in FIG. 12, the same applies hereinafter) is disposed between the coil 82a and the attraction element 84. The upper end of the guide pipe 86 is fixed to the outer peripheral step portion of the suction element 84 by welding or the like, and a filter-equipped lid member 81 having a narrow tube insertion hole is hermetically sealed by welding, brazing, caulking, or the like at the lower end side opening. The area enclosed by the lid member 81, the plunger 85, and the guide pipe 86 is a valve chamber 88.

  A plunger spring 87 for urging the plunger 85 in a direction away from the suction element 84 (downward in FIG. 12) is compressed between the suction element 84 and the plunger 85.

  A mounting opening 86 a is formed between the lower end of the plunger 85 and the lid member 81 in the guide pipe 86, and the inner end surface of the mounting opening 86 a serves as a valve seat (valve seat) 92, and the upper surface (the plunger 85 side) Of the plunger 85 is a stopper surface for stopping the movement of the plunger 85 in the direction away from the suction element 84. The outer periphery of the end of the valve seat block 83 having a rectangular or rectangular cross section opposite to the valve seat side is welded or the like. Are hermetically sealed. The opposite side to the valve seat side of the valve seat block 83 is formed as a cylindrical surface along the outer peripheral surface of the guide pipe 86. The cylindrical surface of the valve seat block 83 and the joint around the mounting opening 86a of the guide pipe 86 Are tightly fitted to a mounting receiving seat 66a (see also FIG. 11) having a circular arc cross section of the receiving side mounting tool 66, which will be described later, and are hermetically joined by welding or the like. It is attached and fixed to the main valve housing 10 via a base 66 and a base end mounting 65.

  At the end of the plunger 85 opposite to the suction element 84 side, a valve body holder 90 for holding the valve body 91 at its free end side so as to be slidable in the thickness direction caulks its wide base end 96. It is attached and fixed by. A leaf spring 94 that urges the valve body 91 in a direction (thickness direction) of pressing the valve body 91 against the valve seat 92 is attached to the valve body holder 90. The valve element 91 slides on the seat surface of the valve seat 92 as the plunger 85 moves up and down.

  The valve seat 92 is provided with a port a, a port b, and a port c in order from the bottom, and the valve body 91 can selectively communicate the port a with the port b and the port b with the port c. , A concave portion 93 that is concave in the thickness direction is provided. One end of the thin tube 95a is connected to the valve seat block 83 so as to communicate only with the port a, one end of the thin tube 95b is connected so as to communicate only with the port b, and one end of the thin tube 95c is connected only to the port c. Are inserted respectively. One end of a thin tube 95d is inserted into the lid member 81.

  On the other hand, as shown in FIGS. 10 and 11, the thin tubes 95a, 95b, 95c, and 95d are routed along the outer surface of the main valve housing 10, and the other end of the thin tube 95a is The first working chamber 55A is connected to the first working chamber 55A via the first inlet / outlet port 56A of one cylinder 50A, the other end of the thin tube 95b is connected to the low pressure port 14, and the other end of the thin tube 95c is connected to the second cylinder 50B of the second cylinder 50B. It is connected to the second working chamber 55B via the two inlet / outlet ports 56B. The other end of the thin tube 95 d is connected to the high-pressure port 11.

  Next, a description will be given of the base-side mounting fixture 65 and the receiving-side mounting fixture 66 for horizontally mounting the four-way pilot valve 80 to the rear of the left side surface of the box-shaped portion 10C of the main valve housing 10. The base end side mounting tool 65 has a rectangular flat plate-like vertical side portion 65a and upper and lower horizontal side portions 65b and 65c, and the vertical side portion 65a (outer peripheral portion) of the box-shaped portion 10C of the main valve housing 10 is formed. It is fixed to the rear part of the left side part by welding or the like. In the side portions 65b and 65c, through holes for set screws 70 provided for connection and fixing to the receiving side mounting fixture 66 are formed, respectively, and the inner side of the through hole in the lower side portion 65c is formed. A burring portion 65d with which the set screw 70 is screwed is formed on the outer peripheral edge.

  On the other hand, the receiving-side mounting fixture 66 has an inverted U-shape such that the base-side mounting fixture 65 is inverted left and right, and has a vertical side section along the outer peripheral surface of the guide pipe 86 of the four-way pilot valve 80. An arcuate mounting seat 66a (see also FIG. 11) is provided, and rectangular flat plate-like lateral sides 66b and 66c are provided at upper and lower ends of the mounting seat 66a. The spacing between the side portions 66b and 66c of the receiving side fitting 66 is the same as that of the base side fitting 65, but the width of the side portions 66b and 66c is wider than that of the base side fitting 65, The upper and lower horizontal sides 66b and 66c of the receiving side mounting fixture 66 are positioned below the upper and lower horizontal sides 65b and 65c of the base end mounting fixture 65, respectively. In the side portions 66b and 66c, there are formed through holes for set screws 70 used for connection and fixing to the base end side mounting fixture 65, respectively, and the inner side of the through hole in the upper side portion 66b is formed. A burring portion 66d with which the set screw 70 is screwed is formed on the outer peripheral edge.

  In attaching the four-way pilot valve 80 to the main valve housing 10, as described above, the vicinity of the joint between the valve seat block 83 and the attachment opening 86 a of the guide pipe 86 is welded to the attachment seat 66 a of the receiving fixture 66. After joining, the receiving-side fixture 66 is fastened and fixed to the proximal-end-side fixture 65 with set screws 70, 70.

  In the four-way pilot valve 80 configured as described above, when the power is turned off, the lower end of the plunger 85 contacts the valve seat block 83 by the urging force of the plunger spring 87 as shown in FIG. It is pushed down to the position where it does. In this state, the valve element 91 is located above the port a and the port b, and the port 93 communicates with the port a and the port b through the recess 93, so that the port c and the valve chamber 88 communicate with each other. Is introduced into the second working chamber 55B via the thin tube 95d → the valve chamber 88 → port c → the thin tube 95c → the second inlet / outlet port 56B, and the high-pressure fluid in the first working chamber 55A is supplied to the first inlet / outlet port 56A → the thin tube 95a. → Port a → concave portion 93 → port b → thin tube 95 b → flows to low pressure port 14 and is discharged.

  On the other hand, when the power is turned on, as shown in FIG. 12B, the plunger 85 is drawn to a position where the upper end thereof comes into contact with the suction element 84 by the suction force of the suction element 84. At this time, the valve element 91 is located above the port b and the port c, and the port 93 communicates with the port b and the port c through the concave portion 93. Therefore, the high-pressure fluid in the high-pressure port 11 flows through the port a and the valve chamber 88. The thin tube 95d → the valve chamber 88 → the port a → the thin tube 95a → is introduced into the first working chamber 55A via the first inlet / outlet port 56A, and the high-pressure fluid in the second working chamber 55B is fed into the second inlet / outlet port 56B → the thin tube 95c → Port c → recess 93 → port b → small tube 95b → low pressure port 14 to be discharged.

  Therefore, when the energization is switched from the energization OFF to the energization ON, the rearward movement stroke is taken, the main valve body 20 moves from the first movement position to the second movement position, and the flow path is switched as described above. When the power supply is switched from the power supply ON to the power supply OFF, the forward movement process is performed, the main valve body 20 moves from the second movement position to the first movement position, and the flow path is switched as described above.

  As described above, in the flow path switching valve 1 of the present embodiment, the following effects are obtained in addition to the effects of the configuration of the main valve 5 described above.

  That is, by switching ON / OFF the energization of the electromagnetic four-way pilot valve 80, the main valve body 20 is reciprocated by utilizing the pressure difference between the high-pressure fluid and the low-pressure fluid flowing in the main valve 5. Thus, cost reduction, power consumption reduction, energy saving, and the like can be achieved as compared with the case where the main valve body 20 is directly moved by an electromagnetic or electric actuator.

  The flow path switching valve according to the present invention can of course be incorporated not only in a heat pump type cooling / heating system, but also in other systems, devices, and equipment.

  The material of the main valve housing 10 and the main valve body 20 is not particularly limited, and may be any material that can withstand the pressure of the fluid to be introduced, such as a metal such as aluminum or stainless steel, or a synthetic resin. There may be.

DESCRIPTION OF SYMBOLS 1 Flow path switching valve 5 Main valve 7 Actuator 10 Main valve housing 10A Upper valve seat 10B Lower valve seat 10C Box-shaped part 10D Front lid member 11 First port 12 Second port 13 Third port 14 Fourth port 17 Valve seat Surface 20 Main valve body 20A Upper half 20B Lower half 21 First layer member 22 Second layer member 23 Third layer member 24 Fourth layer member 29 Compression coil spring 31 First communication path 32 Second communication path 33 Third Communication path 34 Fourth communication path 36 Convex part 44 Rail 45 Ball-type sealing surface separation mechanism 46 Ball 47 Housing part 48 Concave hole 50 Reciprocating drive cylinder 50A First cylinder 50B Second cylinder 55A First working chamber 55B Second working chamber 56A First inlet / outlet port 56B Second inlet / outlet port 58A First push plate 58B Second push plate 80 Four-way pilot valve 83 Valve seat block 85 Plunger 88 Valve chamber 90 Valve body holder 91 Valve body 92 Valve seat 93 Recesses a, b, c Port (four-way pilot valve)
95a, 95b, 95c, 95d Capillary tube D High pressure port on the discharge side S Low pressure port on the suction side C Outdoor entrance / exit port E Indoor entrance / exit port

Claims (7)

At least three in total are provided in the cylindrical main valve housing whose upper opening and lower opening are hermetically sealed by the upper valve seat and the lower valve seat, the upper valve seat and / or the lower valve seat. And a main valve having a main valve body movably disposed in the main valve housing, and a hydraulic actuator for moving the main valve body,
In the main valve body, a communication path for selectively communicating between the ports is provided, and by moving the main valve body, switching between the communicating ports is performed,
The upper valve seat and the lower valve seat are both flat and smooth surfaces to be sealed, and the surfaces to be sealed are arranged to face each other,
The main valve body has a two-part configuration of an upper half part and a lower half part that are integrally movable and vertically movable ,
A flow path switching valve, wherein a U-shaped passage is formed on each of the upper valve seat side and the lower valve seat side by the main valve body .   In the main valve body, at least, at least one communication passage that can communicate one of the ports and the other one is provided, and by moving the main valve body in one direction, between the ports that communicate with each other. The flow path switching valve according to claim 1, wherein flow path switching is performed. 2. A projection having an annular sealing surface that closely contacts an opening of each port in the upper valve seat and / or the lower valve seat at both ends of the communication passage. 3. Or the flow path switching valve according to 2. The actuator includes a reciprocating drive cylinder having a first working chamber and a second working chamber with a variable volume that is air-tightly partitioned by a piston into which a high-pressure fluid in the main valve is introduced, and the first working chamber includes A first step of moving the main valve body in one direction by introducing the high-pressure fluid and discharging the high-pressure fluid from the second working chamber, and introducing the high-pressure fluid into the second working chamber; by discharging the high pressure fluid from the first working chamber, one of claims 1 to 3, characterized in that it is configured to obtain take a second step of moving the main valve body in the other direction to selectively The flow path switching valve according to claim 1. A first cylinder having the first working chamber is provided on a front side of the main valve housing, and a second cylinder having the second working chamber is provided on a rear side of the main valve housing. A first pushing plate connected to a piston rod of the first cylinder is brought into contact with a front surface thereof, and a second pushing plate connected to a piston rod of the second cylinder is brought into contact with a rear surface of the main valve body. The flow path switching valve according to claim 4 , wherein the flow path switching valve is in contact with the flow path switching valve. The first cylinder and the second cylinder have a common piston rod interconnecting the respective pistons, and the first pushing plate and the second pushing plate are fixed to the piston rod, A portion of the piston rod between the first pushing plate and the second pushing plate is inserted into a front-rear through hole provided in the main valve body so as to be slightly vertically movable. The flow path switching valve according to claim 5 , wherein The switching between the first stroke and the second stroke is performed by a four-way pilot valve connected to the first working chamber and the second working chamber, and a high pressure part and a low pressure part of the main valve. The flow path switching valve according to any one of claims 4 to 6 , wherein:

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