JP6475778B2 - Flow path switching valve - Google Patents

Description

  The present invention relates to a rotary flow path switching valve that switches a flow path by rotating a valve body, and more particularly to a flow path switching valve that is suitable for performing flow path switching in a heat pump air conditioning system or the like.

  In general, heat pump type air conditioning systems such as room air conditioners and car air conditioners have compressors, outdoor heat exchangers, indoor heat exchangers, expansion valves, etc., as well as four-way switching valves as flow path (flow direction) switching means, etc. The flow path switching valve is provided.

  As this type of flow path switching valve (four-way switching valve), there are a slide type and a rotary type. For example, a rotary type four-way switching valve having the following configuration is well known. (See also Patent Document 1). That is, a cylindrical main valve housing, a valve seat surface provided on the lower surface side of the main valve housing, and four ports (first, second, third, and fourth ports) opened in the valve seat surface ), And a rotary valve body rotatably disposed in the main valve housing and having a lower surface thereof facing the valve seat surface, and the ports are selectively communicated with each other in the rotary valve body. Accordingly, two U-turn communication paths are provided, and when the rotary valve body assumes the first rotational position, the first port and the second port communicate with each other through one U-turn communication path, and the other U-turn communication path When the third port and the fourth port communicate with each other through the turn communication path and the rotary valve body takes the second rotational position, the first port communicates with the third port through one U-turn communication path, 2nd port and 4th port by the other U-turn communication path Preparative may be mentioned as the typical example those that are adapted to be communicated.

  More specifically, one of the two U-turn communication paths is a high-pressure side U-turn communication path that is connected to the discharge side of the compressor and through which high-pressure refrigerant flows, and the other is connected to the suction side of the compressor. A low-pressure side U-turn communication path through which low-pressure refrigerant flows is connected, the main valve housing (valve chamber) is filled with high-pressure refrigerant, and the lower end surface (seal surface) of the low-pressure side U-turn communication path is the low-pressure side Due to the pressure difference between the low pressure in the U-turn communication path and the high pressure in the valve chamber, it is strongly pressed against the valve seat surface, thereby sealing the low-pressure side U-turn communication path and allowing the high-pressure refrigerant in the valve chamber to escape to the low pressure side. (Valve leakage) is prevented.

JP-A-8-285113

  The conventional flow path switching valve as described above has the following problems to be solved.

  In general, in order to reduce the pressure loss of the fluid flowing through the U-turn communication path, the side view of the communication path is made U-shaped, arc-shaped, kamaboko-shaped, etc., the cross-sectional shape is circular, and the communication path The cross-sectional area of the passage should not be changed over the entire length from one end to the other end, and this is an ideal passage shape. More specifically, an ideal passage shape is formed by bending a tube having a circular cross section into a U shape, an arc shape, a kamaboko shape or the like without changing the cross sectional shape (circular shape).

  On the other hand, in a heat pump type air conditioning system or the like, a swash plate type is often used as a compressor, but the high-pressure refrigerant discharged from the swash plate type compressor is accompanied by pulsation. Therefore, when high-pressure refrigerant flows through the high-pressure side U-turn communication path, the entire rotary valve body vibrates due to the pulsation, and this vibration impairs the sealing performance of the low-pressure side U-turn communication path provided in the same rotary valve body. There is a risk of being. More specifically, when the rotary valve body vibrates, a gap is formed between the seal surface of the low pressure side U-turn communication path and the valve seat surface, and the high pressure refrigerant in the valve chamber passes from this gap to the compressor suction side. There is a problem that valve leakage is likely to occur.

  In particular, when the high-pressure side U-turn communication path is brought close to the ideal path shape, the pressure loss is reduced, but the vibration of the rotary valve body is increased and valve leakage tends to occur. As can be seen from the above, when the high-pressure side U-turn communication path has a rice bowl shape (cross-sectional shape is rectangular) that is not an ideal path shape, the pressure loss increases, but the vibration of the rotary valve body tends to decrease.

  As one measure for suppressing the vibration of the rotary valve body as described above, it is conceivable to bias the rotary valve body against the valve seat surface with a spring member having a larger spring force (set load). However, in this measure, since the frictional force between the rotary valve body and the valve seat surface becomes large, a large driving force is required to rotate the rotary valve body, which is problematic in terms of cost.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to effectively suppress vibrations of the rotary valve body caused by pulsation accompanying high-pressure refrigerant while reducing pressure loss and the like. Accordingly, it is an object of the present invention to provide a flow path switching valve capable of improving the sealing performance of the low pressure side U-turn communication path and making it difficult for valve leakage.

  In order to achieve the above object, a flow path switching valve according to the present invention basically includes a cylindrical main valve housing, a valve seat surface provided on an upper surface side or a lower surface side of the main valve housing, the valve There are four or more ports that open in the seat surface, and a rotary valve body that is rotatably disposed in the main valve housing and whose upper surface or lower surface faces the valve seat surface. In addition, in order to selectively communicate between the ports, a low-pressure side U-turn communication passage through which low-pressure fluid flows and a high-pressure passage forming member provided with a high-pressure side U-turn communication passage through which high-pressure fluid flows are vertically moved. It is characterized by being housed and held slidably in the direction.

  In a preferred embodiment, a first urging member that urges the rotary valve body in a direction in which the rotary valve body is pressed against the valve seat surface, and a second urging member that urges the high-pressure passage forming member to the side opposite to the valve seat surface. A member is provided.

  In a further preferred aspect, the second urging member is provided at both end portions in the circumferential direction of the high pressure passage forming member.

  In another preferred embodiment, a protrusion for reducing the frictional resistance during rotation is provided on the surface of the high-pressure passage forming member opposite to the surface facing the valve seat surface.

  In another specific preferred aspect, when the first, second, third and fourth ports are opened in the valve seat surface and the rotary valve body assumes the first rotational position, the high-pressure side U-turn link The first port and the second port communicate with each other through the passage, and the third port and the fourth port communicate with each other through the low-pressure side U-turn communication passage, and when the rotary valve body takes the second rotational position, The first port and the third port communicate with each other through the high-pressure side U-turn communication path, and the second port and the fourth port communicate with each other through the low-pressure side U-turn communication path.

  In another preferred embodiment, the low-pressure side U-turn communication passage includes a valve body passage portion formed in the rotary valve body, and a low-pressure passage defining member provided on the valve seat surface side in the valve body passage portion. The valve body passage portion has a generally arcuate shape or a semi-cylindrical shape in a side view with the valve seat surface side opened, and the outer peripheral side has a substantially semicircular or nearly semi-elliptical cross-sectional shape. The low-pressure passage defining member has a seal surface that is in contact with the valve seat surface, and cooperates with the valve body passage portion so that the cross-sectional shape of the low-pressure side U-turn communication passage is circular or an elliptical shape close thereto. In addition, the cross-sectional area is formed so as to be equal over the entire length from one end to the other end.

  In a more preferred aspect, the low-pressure passage defining member is provided with openings constituting one end and the other end of the low-pressure side U-turn communication passage, and a mountain-shaped protrusion is provided from the center to the openings at both ends. .

  In a further preferred aspect, the mountain-like protrusion has a semicircular surface or a semi-elliptical surface close to it.

  In the flow path switching valve according to the present invention, the high pressure passage forming member provided with the high pressure side U-turn communication passage through which the high pressure fluid flows is accommodated in the rotary valve body as a separate body that is slidable in the vertical direction. In addition, since the high pressure passage forming member is held in the rotary valve body while being pressed against the main valve housing, the main valve housing having sufficient strength receives the impact caused by the pulsation caused by the high pressure refrigerant. It is not transmitted to the rotating valve body. Therefore, it is possible to effectively suppress the vibration of the rotary valve body due to the pulsation accompanying the high-pressure refrigerant, and as a result, the sealing performance of the low-pressure side U-turn communication path can be improved while reducing the pressure loss. This can prevent valve leakage.

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

It is a longitudinal cross-sectional view which shows the 1st communication state of one Embodiment of the flow-path switching valve concerning this invention, and is sectional drawing which follows the VV arrow line of FIG. 3 (A). It is a longitudinal cross-sectional view which shows the 2nd communication state of one Embodiment of the flow-path switching valve concerning this invention, and is sectional drawing which follows the WW arrow line of FIG. 3 (B). It is a figure with which it uses for description of the flow-path switching operation | movement in the flow-path switching valve of this embodiment, (A) is a state in which a rotary valve body exists in a 1st rotation position, (B) is a rotary valve body being 2nd. The lower surface arrangement | positioning figure which respectively shows the state in the rotation position. The disassembled perspective view which shows the actuator part for mainly rotating the rotary valve body in the flow-path switching valve of this embodiment. The disassembled perspective view which mainly shows the main valve housing and the rotating shaft member part in the flow-path switching valve of this embodiment. The disassembled perspective view which mainly shows a rotary valve body and a valve seat member part in the flow-path switching valve of this embodiment. The disassembled perspective view with which the rotary valve body and high pressure channel | path formation member in the flow-path switching valve of this embodiment are provided for detailed description. (A) is a disassembled perspective view used for detailed description of the rotary valve body and the low-pressure passage defining member in the flow path switching valve of the present embodiment, and (B) is a bottom surface arrangement view of the rotary valve body. Sectional drawing cut | disconnected in general according to the UU arrow line of FIG. 6 in the assembly state of the flow-path switching valve of this embodiment.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 are longitudinal sectional views showing a first communication state and a second communication state, respectively, of an embodiment of a flow path switching valve according to the present invention.

  In the present specification, descriptions indicating positions, directions such as up and down, left and right, and front and rear are provided for the sake of convenience in accordance with the drawings in order to avoid complicated explanation, and are actually incorporated in a heat pump type air conditioning system or the like. It does not necessarily indicate the position and direction in the state of being pressed.

  In each drawing, the gap formed between the members, the separation distance between the members, etc. are larger than the 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 of the illustrated embodiment is a four-way switching valve 1, which is used for switching a flow path in a heat pump air conditioning system, and includes a rotary main valve 5, a fluid pressure actuator 7, and a four-way pilot. A valve 8 is provided.

  In the following, first, the main valve 5 will be mainly described, and then the actuator 7 and the four-way pilot valve 8 will be described.

<Configuration and operation of main valve 5>
As shown in FIGS. 6 and 7 in addition to FIGS. 1 and 2, the main valve 5 is arranged in the main valve housing 10 and is rotatable and vertically movable in the main valve housing 10. The rotary valve body 20 is provided, and a rotary shaft member 30 for rotating the rotary valve body 20 is provided.

  The main valve housing 10 is made of metal such as aluminum or stainless steel, and is fixed by press fitting, brazing, welding or the like so as to hermetically seal the cylindrical body 10C and the upper surface opening of the body 10C. The thick disc-shaped lid plate member 10A and the thick disc-shaped bottom plate fixed to the barrel portion 10C in the same manner as the lid member 10A so as to hermetically seal the lower surface opening of the barrel portion 10C. Member 10B. The bottom plate member 10B also serves as a valve seat member, and its upper surface (inner surface) is a flat and smooth valve seat surface 12. As shown in FIG. 3, the bottom plate member 10B has a first port pD, a second port formed of a circular opening and a pipe joint at 90 ° intervals on the same circumference around the rotation axis O of the rotary valve body 20. A port pC, a third port pE, and a fourth port pS are provided vertically.

  In the four-way switching valve 1 of the present embodiment, when incorporated in a heat pump air conditioning system, for example, the first port pD is connected to the compressor discharge side, the second port pC is connected to the outdoor heat exchanger, The 3 port pE is connected to the indoor heat exchanger, and the fourth port pS is connected to the compressor suction side.

  5 and 6, the rotary shaft member 30 has a small-diameter convex portion 31, an upper large-diameter portion 32, an intermediate shaft portion 33, a square engaging portion 34, and a lower-end small-diameter portion 36 in order from the top. Have A fitting insertion hole 13 through which the rotary shaft member 30 is inserted is formed in the center of the cover plate member 10A in the main valve housing 10, and a lower end small diameter portion of the rotary shaft member 30 is formed in the upper surface side center of the bottom plate member 10B. A recess 14 for rotatably supporting 36 is provided.

  In the rotary shaft member 30, a lower end portion of a rotary drive body 65 of an actuator 7 described later is integrally coupled to an upper end portion including the small-diameter convex portion 31 by welding or the like. An annular groove 33a (FIG. 5) in which a C-shaped stopper 38 also serving as a spring receiver is fitted is formed on the upper portion of the intermediate shaft portion 33, and a thrust bearing 37 made of resin is formed by the stopper 38. The rotary shaft member 30 is externally fitted and held rotatably.

  A square bar 35 fitted in a square groove 29 provided at the center of the lower portion of the rotary valve body 20 is fitted to the square engagement portion 34 of the rotary shaft member 30 so as to be rotated. The valve body 20 is rotated integrally with the rotary shaft member 30. In addition, you may insert the square engaging part 34 of the rotating shaft member 30 in the metal square bar 35 insert-molded in the square groove | channel 29 previously.

  An O-ring 49 as a seal member is interposed between the upper large-diameter portion 32 of the rotary shaft member 30 and the fitting insertion hole 13 of the lid plate member 10A.

  The rotary valve body 20 has a short columnar base portion 21 that is rotatably disposed in the main valve housing 10 (valve chamber 11) and whose lower surface faces the valve seat surface 12. As shown in FIGS. 6 to 9 in addition to FIGS. 1 and 2, the portion 21 is provided with a stepped through hole 22 through which the rotary shaft member 30 is passed. A compression coil spring (first coil) that urges the rotary valve body 20 (base portion 21) against the valve seat surface 12 between the upper stepped portion 22 and the stopper 38 fitted to the rotary shaft member 30. 1 biasing member) 39 is retracted.

  In addition, a rice bowl-shaped high-pressure passage forming member 40 having a high-pressure side U-turn communication passage 41 through which a high-pressure refrigerant flows is provided at one end side (with respect to the rotation axis O) of the rotary valve body 20 in the vertical direction. A housing portion 23 is provided that is slidably inserted and held at the other end, and a low-pressure side U-turn communication passage 42 through which the low-pressure refrigerant flows is provided at the other end side.

  More specifically, the high-pressure passage forming member 40 is disposed on an annular inwardly projecting end edge portion 23 a having a rice bowl-like outer shape in plan view at the lower end of the housing portion 23. Further, the high-pressure side U-turn communication passage 41 formed in the high-pressure passage forming member 40 has a generally arcuate or arcuate shape in a side view opened on the lower surface side, and the lower surface of the inwardly projecting edge portion 23a is The contact surface 16 (refer to FIG. 8B and FIG. 9) of the high-pressure side U-turn communication passage 41 (to the valve seat surface 12). The lower surface (opening) of the high-pressure side U-turn communication path 41 and the lower surface of the inwardly projecting end edge 23a selectively communicate between adjacent ports (pD-pC, pD-pE) including the first port pD. It is the size to get. Note that a part of the high-pressure refrigerant introduced into the high-pressure side U-turn communication passage 41 is introduced into the valve chamber 11 through the gap between the high-pressure passage forming member 40 and the accommodating portion 23, and thus the contact surface 16. Need not have a sealing property.

  Further, near the both ends on the upper surface side (in the circumferential direction) of the high-pressure passage forming member 40, a tongue-like handle portion 43 is provided so as to protrude in the lateral direction. On the other hand, the corresponding part on the upper surface side of the base part 21 is provided with recesses 26, 26 into which the tongue-like handle parts 43, 43 are inserted so as to be movable up and down. In addition, a storage hole 27 is formed in which a compression coil spring (second urging member) 25 for urging the high-pressure passage forming member 40 to the side opposite to the valve seat surface 12 (the cover plate member 10A side) is loaded. ing.

  Further, on the upper surface of the high-pressure passage forming member 40, an upward convex spherical crown-like protrusion is formed so as to reduce the frictional resistance during rotation by reducing the contact area between the high-pressure passage forming member 40 and the lower surface of the lid plate member 10A. A plurality of portions 44 are provided (in the illustrated example, three locations near the center and near both ends).

  On the other hand, the low pressure side U-turn communication passage 42 provided in the rotary valve body 20 includes a valve body passage portion 46 formed in the base portion 21 and a low pressure passage image provided on the lower surface side of the valve body passage portion 46. It is comprised by the component member 47.

  The valve body passage portion 46 has a substantially arcuate shape with a substantially arcuate shape (bow shape) opened on the lower surface side (valve seat surface 12 side), and the upper portion (outer peripheral side) has a substantially semicircular shape or a semi-elliptical shape close thereto. It has a shape.

  On the other hand, the low pressure passage defining member 47 is in the shape of glasses in plan view having an annular portion 45 having circular openings 49 at both ends, and the base portion 21 is covered on the upper side of the low pressure passage defining member 47, The upper surface of the eyeglass-like outer frame portion is joined and joined to the peripheral edge of the lower end of the valve body passage portion 46 of the base portion 21 by ultrasonic welding or laser welding.

  The low-pressure passage defining member 47 has annular seal surfaces 17 and 17 that are in contact with the valve seat surface 12 at both ends of the lower surface (the outer periphery of the lower surface of the circular opening 49), as can be understood with reference to FIG. Further, the cross-sectional shape of the low-pressure side U-turn communication passage 42 is made into a circular shape or an oval shape close to it in cooperation with the valve body passage portion 46, and has substantially the same cross-sectional area over the entire length from one end to the other end. Therefore, a mountain-shaped protrusion 48 is provided from the central portion to the circular openings 49 at both ends. As shown in FIG. 9, the mountain-shaped protrusion 48 has a semicircular or nearly semi-elliptical surface (that is, a circular arc portion) in cross section.

  That is, the low-pressure side U-turn communication passage 42 has a lower side or inner peripheral portion defined by the low-pressure passage defining member 47, and an upper side or outer peripheral side portion of the base portion 21 (the valve body passage portion 46). The cross-sectional shape defined in (1) is a circular shape or an elliptical shape close to the circular shape, and a substantially inverted U shape or an arc shape in side view.

  In this example, the passage diameter of the low pressure side U-turn communication passage 42 and the diameter of the second to fourth ports pC, pE, and pS are substantially the same diameter. (The circular openings 49, 49 at both ends of the low-pressure passage defining member 47) are selectively positioned directly above the three ports of the second to fourth ports pC, pE, pS (that is, the low-pressure passage defining member 47). The circular openings 49 and 49 at both ends of 47 are formed 90 degrees apart on the same circumference centering on the rotation axis O of the rotary valve body 20), thereby adjacent to each other including the fourth port pS. Ports (pS-pE, pS-pC) are selectively communicated.

  In addition to the above, in this embodiment, when the rotary valve body 20 rotates, the ball-type seal surface separation mechanism that separates the contact surface 16 and the seal surface 17 on the rotary valve body 20 side from the valve seat surface 12 of the bottom plate member 10B. Is provided.

  As shown in FIGS. 6 and 9, the ball-type sealing surface separation mechanism includes a plurality (three in the illustrated example) of ball holders 55 including a ball 56, a case 57, and a lid member 58. The ball holding body 55 holds the ball 56 in a state in which a part of the ball 56 protrudes downward, in a state where the ball 56 is rotatable and substantially prevented from moving. The ball holding body 55 is a rotary valve body. The ball 56 is mounted in a mounting hole 59 provided at three positions on the outer periphery of the lower portion 20 at intervals of 120 ° with a part of the ball 56 protruding downward. In addition, the bottom plate member 10B is configured such that the contact surface 16 and the seal surface 17 on the rotary valve body 20 side are not separated from the valve seat surface 12 of the bottom plate member 10B before and after the rotation of the rotary valve body 20 is started. A part of the ball 56 is fitted, and when the rotary valve body 20 is rotated (while the flow path is switched), the ball 56 is formed in a substantially conical shape so that the ball 56 rolls while pushing up the rotary valve body 20. Two sets of three concave holes 18 are provided at intervals of 120 °. In the present embodiment, since the rotation angle for switching the flow path is 90 °, the angular interval between the sets of the recessed holes 18 is 30 °.

  In such a seal surface separation mechanism, before the rotation of the rotary valve body 20 and at the end of the rotation, as shown in FIG. 9, a part of the ball 56 is fitted in the recessed hole 18 of the bottom plate member 10B. When the rotary valve body 20 starts to rotate 90 ° from this state, the ball holding body 55 moves (rotates) in the circumferential direction, and accordingly, the ball 56 causes the rotary valve body 20 to urge the compression coil spring 39. Rolls out of the recessed hole 18 while pushing up against the above. Thereby, the contact surface 16 and the seal surface 17 of the rotary valve body 20 are separated from the valve seat surface 12 of the bottom plate member 10B. When the rotary valve body 20 rotates 90 °, the ball 56 is fitted into the next concave hole 18, so that the rotary valve body 20 is pushed down by the urging force of the compression coil spring 39, and the contact surface 16 of the rotary valve body 20. And the sealing surface 17 is pressed against the valve seat surface 12.

<Configuration and operation of actuator 7>
Next, the fluid pressure type actuator 7 for rotating the rotary valve body 20 will be described.

  The actuator 7 of the present embodiment is a fluid pressure type that utilizes the differential pressure between the high-pressure refrigerant and the low-pressure refrigerant that circulates in the main valve 5, and FIG. 4 may be referred to in addition to FIGS. As can be seen, a cylindrical portion 61 with an upper lid 62 whose lower end is fixed on the lid plate member 10A of the main valve housing 10 by welding or the like, and a ceiling portion that is slidably fitted in the cylindrical portion 61. A thick cylindrical pressure receiving moving body 60 and a columnar rotational driving body 65 inserted in the pressure receiving moving body 60 are provided.

  The pressure-receiving moving body 60 is fitted and fixed to the upper surface of the lid plate member 10A and is fitted between the pressure-receiving moving body 60 and the cylindrical portion 61. By 63, it moves up and down linearly, but its rotation is prevented.

  The pressure receiving moving body 60 and the rotation driving body 65 are respectively provided with a feeding female screw 66 and a feeding male screw 67 as motion conversion mechanisms for converting the vertical movement of the pressure receiving moving body 60 into the rotation movement of the rotation driving body 65. (Not shown in FIG. 4). Since the rotation driving body 65 is screwed to the pressure receiving moving body 60, the rotation driving body 65 is relatively rotated in the pressure receiving moving body 60 as the pressure receiving moving body 60 moves in the vertical direction. When the drive body 65 rotates, the rotary shaft member 30 and the rotary valve body 20 connected to the rotary drive body 65 also rotate together. Here, when the pressure receiving moving body 60 moves upward, the rotation driving body 65, the rotary shaft member 30, and the rotary valve body 20 rotate counterclockwise (viewed from below), and when the pressure receiving moving body 60 moves downward, The rotary drive body 65, the rotary shaft member 30, and the rotary valve body 20 rotate clockwise (viewed from below).

  On the upper outer periphery of the pressure-receiving moving body 60, a sealing member (air-tightly sealing between the inner peripheral surface of the cylindrical portion 61 and partitioning the cylindrical portion 61 into an upper chamber 51 and a lower chamber 52 with variable volume) Here, an O-ring 71, for example, a seal member made of a sliding ring 72 made of Teflon (registered trademark), and a ring member 73 made of metal, for example, for locking the seal member are mounted by caulking or the like.

  FIG. 1 shows a state where the pressure receiving moving body 60 is in the lowest lowered position and the rotary valve body 20 is in the first rotating position, and FIG. 2 shows that the pressure receiving moving body 60 is in the highest raised position. The state which the rotary valve body 20 has taken the 2nd rotation position is shown. In this example, the angle difference between the first rotation position and the second rotation position, that is, the rotation angle required for the flow path switching is 90 °.

  In addition, a lower port 54 for introducing and discharging a high pressure fluid to the lower chamber 52 is provided at the lower portion of the cylindrical portion 61, and an upper lid 62 for introducing and discharging the high pressure fluid to the upper chamber 51. An upper port 53 is provided.

  Note that the motion conversion mechanism for converting the vertical movement of the pressure-receiving moving body 60 into the rotational motion of the rotary drive body 65 is not limited to the one using the feed screw as described above. It is possible to employ a ball, a housing portion for the ball, and a spiral groove as disclosed in Japanese Patent Publication.

<Configuration and operation of the four-way pilot valve 8>
Next, the four-way pilot valve 8 will be described.

  In the present embodiment, the flow path switching is performed by an electromagnetic type connected to the first port pD, which is the high pressure portion, the upper port 53, the lower port 54, and the fourth port pS, which is the low pressure portion, by the thin tubes # 1 to # 4. The four-way pilot valve 8 is used.

  Since the structure of the four-way pilot valve 8 is well known, the description of the structure is omitted. If necessary, refer to, for example, JP-A-2006-114133.

  In this four-way pilot valve 8, the port a connected to the upper port 53 via the thin tube # 2, the low pressure port b connected to the fourth port pS via the thin tube # 4, and the thin tube # 3 to the lower port 54. And a low-pressure port d connected to the first port pD via the narrow tube # 1.

  In this example, when energization is ON, the high pressure port d and the port c communicate with each other, and the port a and the low pressure port b communicate with each other, so that the high pressure fluid flowing into the port pD (discharge side high pressure port) passes through the lower port 54. While being introduced into the lower chamber 52, the high pressure fluid in the upper chamber 51 is discharged from the upper port 53 to the fourth port pS (suction side low pressure port).

  On the other hand, when the energization is turned off, the high pressure port d and the port a communicate with each other, and the port c and the low pressure port b communicate with each other, so that the high pressure fluid flowing into the port pD (discharge side high pressure port) passes through the upper port 53. The high pressure fluid in the lower chamber 52 is discharged from the lower port 54 to the fourth port pS (suction side low pressure port).

  Therefore, when energization to the four-way pilot valve 8 is turned ON, the pressure receiving moving body 60 moves up, and thereby the rotation driving body 65, the rotation shaft member 30, and the rotation valve body 20 are counterclockwise (as viewed from below). 90 ° (from the first rotation position to the second rotation position), and as shown in FIG. 2 and FIG. 3 (B), the first port pD and the first port are connected by the high-pressure side U-turn communication path 41. The third port pE communicates with the second port pC and the fourth port pS through the low pressure side U-turn communication passage 42 (second communication state in which the rotary valve body 20 is in the second rotational position).

  On the other hand, when the energization to the four-way pilot valve 8 is turned off, the pressure receiving moving body 60 moves downward, and the rotation driving body 65, the rotation shaft member 30, and the rotation valve body 20 are rotated 90 ° clockwise (viewed from below). As shown in FIGS. 1 and 3A, the first port pD and the second port pC are rotated by the high-pressure side U-turn communication passage 41 as shown in FIGS. Are communicated with each other, and the third port pE and the fourth port pS are communicated with each other by the low pressure side U-turn communication passage 42 (first communication state in which the rotary valve body 20 is in the first rotation position).

<Effects of the four-way switching valve (channel switching valve) 1>
In the four-way switching valve 1 of the present embodiment configured as described above, a housing portion 23 is provided on one end side of the rotary valve body 20, and a high-pressure side U-turn communication path through which high-pressure refrigerant flows in the housing portion 23. The high pressure passage forming member 40 provided with 41 is slidably inserted and held in the up and down direction, and the high pressure passage forming member 40 is pressed against the cover plate member 10A by the compression coil spring 25 (on the counter valve seat surface 12 side). ), The pulsation caused by the high-pressure refrigerant flowing through the high-pressure side U-turn communication path 41 is higher than the base portion 21 of the rotary valve body 20 provided with the low-pressure side U-turn communication path 42. The passage forming member 40 is held by the cover plate member 10A of the main valve housing 10 and absorbed and attenuated.

  Therefore, the vibration of the rotary valve body 20 due to the pulsation accompanying the high-pressure refrigerant can be effectively suppressed. Therefore, even if the high-pressure refrigerant is accompanied by the pulsation, the seal surface 17 of the low-pressure side U-turn communication path 42 It is difficult to form a gap between the valve seat surface 12 and, as a result, it is possible to effectively suppress the occurrence of valve leakage in which high-pressure refrigerant in the main valve housing 10 (valve chamber 11) escapes to the compressor suction side. .

  Further, the high-pressure side U-turn communication passage 41 provided in the high-pressure passage forming member 40 has a generally arcuate or arcuate shape in a side view when the lower surface side is opened, and a cross section thereof is shown in FIG. As can be clearly understood, since the upper part (outer peripheral side) has a semicircular shape, the pressure loss can be reduced as compared with the rice bowl shape (cross-sectional shape is rectangular) as described in Patent Document 1 described above. .

  Therefore, in the four-way switching valve 1 of the present embodiment, it is possible to improve the sealing performance of the low pressure side U-turn communication path 42 and reduce valve leakage while reducing pressure loss and the like.

  In addition to the above, in the four-way switching valve 1 of the present embodiment, the low-pressure side U-turn communication passage 42 provided in the rotary valve body 20 includes a valve body passage portion 46 formed in the base portion 21 and the valve body passage. The low pressure side U-turn communication passage 42 is divided into a semi-cylindrical shape having a circular arc shape (bow shape) when viewed from the side, and has a cross-sectional shape. The cross-sectional area of the passage is not changed over the entire length from one end to the other end.

  In other words, the low-pressure side U-turn communication passage 42 has an ideal passage shape in which a tube having a circular cross section is curved in an arc shape without changing its cross sectional shape (circular shape), and has no corners, steps, catches, or the like. Therefore, it is difficult to generate a vortex that causes an increase in pressure loss.

  In addition, since the pressure resistance increases, the difference in pressure between the inside and outside is large compared to conventional valve bodies with a cross-sectional shape of a semi-cylindrical shape, a rounded rectangular shape, or a relatively flat elliptical shape and a non-uniform cross-sectional area. Even if it becomes, it becomes difficult to deform | transform. Therefore, the sealing property of the low voltage | pressure side U-turn communication path 42 can be improved, and it is hard to produce a valve leak, without causing a cost increase, an enlargement, etc.

  Furthermore, since the low pressure passage defining member 47 also serves as a reinforcing member for the rotary valve body 20, the rotary valve body 20 can be hardly deformed even when the high and low pressure difference is large.

  Further, since the passage diameter of the low pressure side U-turn communication passage 42 and the diameters of the second to fourth ports pC, pE, and pS are substantially the same diameter, Shrinkage does not occur, which can effectively reduce pressure loss.

  In the above embodiment, an example in which the present invention is applied to a four-way switching valve has been described, but it goes without saying that the present invention can be similarly applied to a six-way switching valve or the like.

  Of course, the above-described flow path switching valve according to the present invention can be incorporated not only in the heat pump air conditioning system but also in other systems, devices, and devices.

1 Four-way switching valve (channel switching valve)
5 Main valve 7 Actuator 8 Four-way pilot valve 10 Main valve housing 10A Cover plate member 10B Bottom plate member 10C Body 11 Valve chamber 12 Valve seat surface 16 Contact surface (high-pressure side U-turn communication path)
17 Seal surface (low pressure side U-turn communication path)
20 Rotating valve body 21 Base part 23 Housing part 25 Compression coil spring (second urging member)
30 Rotating shaft member 39 Compression coil spring (first biasing member)
40 High-pressure passage forming member 41 High-pressure side U-turn communication passage 42 Low-pressure side U-turn communication passage 43 Tongue-shaped handle portion 45 Annular portion 46 Valve body passage portion 47 Low-pressure passage defining member 48 Mountain-shaped protrusion 49 Circular opening 51 Upper chamber 52 Lower chamber 53 Upper port 54 Lower port 55 Ball holder 60 Pressure receiving moving body 65 Rotation drive body pD First port (discharge side high pressure port)
pC 2nd port (outdoor entrance / exit port)
pE 3rd port (inside / outside port)
pS 4th port (suction side low pressure port)

Claims (8)

  A cylindrical main valve housing, a valve seat surface provided on the upper surface side or the lower surface side of the main valve housing, four or more ports opened to the valve seat surface, and a pivotable arrangement in the main valve housing A low pressure side U-turn link through which a low pressure fluid flows to selectively communicate between the ports in the rotary valve body, the rotary valve body having an upper surface or a lower surface facing the valve seat surface. A flow path switching valve characterized in that a high pressure passage forming member provided with a high pressure side U-turn communication passage through which a high pressure fluid flows is accommodated and held slidably in the vertical direction.   A first urging member that urges the rotary valve body in a direction in which the rotary valve body is pressed against the valve seat surface; and a second urging member that urges the high-pressure passage forming member to the side opposite to the valve seat surface. The flow path switching valve according to claim 1, wherein:   The flow path switching valve according to claim 2, wherein the second urging member is provided at both end portions in the circumferential direction of the high-pressure passage forming member.   The protrusion for reducing the frictional resistance at the time of rotation is provided in the surface on the opposite side to the surface facing the said valve seat surface of the said high pressure channel | path formation member, The Claim 1 to 3 characterized by the above-mentioned. The flow path switching valve according to any one of the above. First, second, third and fourth ports open on the valve seat surface,
When the rotary valve body assumes the first rotational position, the first port and the second port communicate with each other through the high-pressure side U-turn communication path, and the third port and the fourth port communicate with each other through the low-pressure side U-turn communication path. Communicated with
When the rotary valve body assumes the second rotational position, the first port and the third port communicate with each other through the high pressure side U-turn communication path, and the second port and the fourth port communicate with each other through the low pressure side U-turn communication path. The flow path switching valve according to any one of claims 1 to 4, wherein the flow path switching valve is configured to communicate with each other.   The low-pressure side U-turn communication path is divided into a valve body passage portion formed in the rotary valve body and a low-pressure passage defining member provided on the valve seat surface side in the valve body passage portion, The valve body passage portion has a generally arcuate shape that is substantially arcuate in side view with the valve seat surface side opened, and has a semicircular or substantially semicircular cross-sectional shape on the outer peripheral side. The component member has a seal surface that is in contact with the valve seat surface, and in cooperation with the valve body passage portion, the low-pressure side U-turn communication passage has a circular or nearly elliptical cross-sectional shape, and the other end from one end. The flow path switching valve according to any one of claims 1 to 5, wherein the flow path switching valve is formed to have an equal cross-sectional area over the entire length to the end.   The low-pressure passage defining member is provided with an opening that constitutes one end and the other end of the low-pressure side U-turn communication passage, and is provided with a mountain-shaped protrusion from the center to the opening at both ends. The flow path switching valve according to claim 6.   8. The flow path switching valve according to claim 7, wherein the mountain-shaped protrusion has a semicircular surface or a semi-elliptical surface close to the cross-sectional shape.

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