阅读说明：本技术 流路切换阀 (Flow path switching valve ) 是由 木船仁志 森田纪幸 于 2019-12-16 设计创作，主要内容包括：本发明提供一种流路切换阀,其能够使施加于密封部分的按压载荷(分布)均匀,提高密封性。多个(两个)滑动阀芯(21、31)以能够在轴线(O)方向上滑动的方式配置在多个端口(五个端口(pB～pF))沿轴线(O)方向排列并开口的阀座面(82)上,在其间具有规定大小的间隙(空隙)(G1)并沿轴线(O)方向排列配设,分别设置有使所述多个端口(五个端口(pB～pF))中的相邻的端口连通的大小的U形转弯连通路(25、35)。(The invention provides a flow path switching valve, which can make the pressing load (distribution) applied to a sealing part uniform and improve the sealing property. A plurality of (two) slide valve bodies (21, 31) are arranged on a valve seat surface (82) in which a plurality of ports (five ports (pB-pF)) are arranged and opened in the direction of an axis (O) in a manner of being capable of sliding in the direction of the axis (O), a gap (gap) (G1) with a predetermined size is arranged between the ports and the valve seat surface in the direction of the axis (O), and U-turn communication passages (25, 35) with a size allowing adjacent ports of the plurality of ports (five ports (pB-pF)) to communicate with each other are respectively provided.)

1. A flow path switching valve is characterized by comprising:

a cylinder-type housing having a valve chamber partitioned by a pair of pistons and opened with a port;

a valve seat member that is provided in the housing and that has a valve seat surface on which a plurality of ports are arranged in the axial direction and open;

a plurality of spool bodies that are disposed on the valve seat surface so as to be slidable in an axial direction, that have gaps of a predetermined size therebetween, that are arranged in an axial line direction, and that are each provided with a communication passage of a size that allows adjacent ports of the plurality of ports to communicate with each other; and

a connecting body for connecting the pair of pistons so as to be movable integrally,

the plurality of slide valve bodies are slid on the valve seat surface by the coupling body in accordance with the reciprocating movement of the pair of pistons, and the plurality of ports are selectively communicated through the communication passages provided in the plurality of slide valve bodies.

2. The flow path switching valve according to claim 1,

a plurality of openings into which the plurality of slide valve bodies are slidably fitted in a direction perpendicular to the valve seat surface are formed in the coupling body.

3. The flow path switching valve according to claim 1 or 2,

the clearance is located on the port between the adjacent spool in the middle of the flow passage switching.

4. The flow path switching valve according to any one of claims 1 to 3,

the gap is formed linearly.

5. The flow path switching valve according to any one of claims 1 to 3,

the gap is formed in a curved shape.

6. The flow path switching valve according to claim 5,

the interval in the direction perpendicular to the axis is the narrowest in the curved gap.

7. The flow path switching valve according to claim 5,

an insertion portion extending in the axial direction is provided on one of the adjacent slide valve elements, and a semi-cylindrical outer cylinder portion extending in the axial direction and covering the outer periphery of the insertion portion is provided on the other of the adjacent slide valve elements, and the curved gap is formed by the outer cylinder portion and the insertion portion.

8. The flow path switching valve according to claim 7,

the distance between the inner peripheral surface of the outer tube section and the outer peripheral surface of the fitting section is the narrowest in the curved gap.

9. The flow path switching valve according to claim 7 or 8,

the distance between the inner peripheral surface of the outer tube section and the outer peripheral surface of the fitting section is smaller than the axial gap formed between the end surface of the fitting section and the end surface of the other slide valve body and the axial gap formed between the end surface of the outer tube section and the end surface of the one slide valve body.

Technical Field

The present invention relates to a flow path switching valve that switches flow paths by moving a valve body, and more particularly to a flow path switching valve suitable for switching flow paths in a heat pump type air-cooling/heating system or the like.

Background

In general, a heat pump type air-cooling/heating system such as an indoor air conditioner or a car air conditioner includes a flow path switching valve as a flow path (flow direction) switching mechanism in addition to a compressor, an outdoor heat exchanger, an indoor heat exchanger, an expansion valve, and the like.

As such a flow path switching valve, a four-way switching valve is known, but a six-way switching valve may be used instead of the four-way switching valve.

An example of a heat pump type cooling and heating system including a six-way switching valve will be briefly described below with reference to fig. 9(a) and (B). The heat pump type cooling and heating system 100 illustrated in the figure is switched in operation modes (cooling operation and heating operation) by a six-way switching valve 180, and basically includes a compressor 110, an outdoor heat exchanger 120, an indoor heat exchanger 130, a cooling expansion valve 150, and a heating expansion valve 160, and the six-way switching valve 180 having six ports pA, pB, pC, pD, pE, and pF is disposed therebetween.

When the cooling operation mode is selected, as shown in fig. 9(a), the high-temperature and high-pressure refrigerant discharged from the compressor 110 is guided from the port pA of the six-way switching valve 180 to the outdoor heat exchanger 12a via the port pB, exchanges heat with outdoor air, condenses, becomes a high-pressure two-phase gas-liquid or liquid refrigerant, and is introduced into the expansion valve 150 for cooling. The high-pressure refrigerant is decompressed by the expansion valve 150 for cooling, the decompressed low-pressure refrigerant is introduced from the port pE of the six-way switching valve 180 into the indoor heat exchanger 130 via the port pF, and is evaporated by exchanging heat (cooling) with the indoor air, and the low-temperature and low-pressure refrigerant is returned from the indoor heat exchanger 1 to the intake side of the compressor 110 via the port pD from the port pC of the six-way switching valve 180.

On the other hand, when the heating operation mode is selected, as shown in fig. 9B, the high-temperature and high-pressure refrigerant discharged from the compressor 110 is guided from the port pA of the six-way switching valve 180 to the indoor heat exchanger 130 via the port pF, where it exchanges heat (heats) with the indoor air, condenses, and is introduced into the heating expansion valve 160 as a high-pressure two-phase gas-liquid or liquid refrigerant. The high-pressure refrigerant is decompressed by the heating expansion valve 160, the decompressed low-pressure refrigerant is introduced from the port pC of the six-way switching valve 180 into the outdoor heat exchanger 120 through the port pB, and is evaporated by heat exchange with outdoor air, and the low-temperature low-pressure refrigerant is returned from the outdoor heat exchanger 120 from the port pE of the six-way switching valve 180 to the intake side of the compressor 110 through the port pD.

As a six-way switching valve (flow path switching valve) incorporated in the heat pump type cooling/heating system or the like described above, a sliding type six-way switching valve described in patent document 1 is known. The six-way switching valve of the sliding type includes a valve main body (housing) having a slide valve element therein and an electromagnetic pilot valve (four-way pilot valve), the housing is provided with the six ports pA to pF, and the slide valve element is disposed so as to be slidable in the left-right direction. Two working chambers are provided on the left and right sides of the slide valve body in the housing, the two working chambers are connected to the compressor discharge side and the compressor suction side via pilot valves, and are defined by a pair of left and right piston-type gaskets coupled to the slide valve body, respectively, and the flow path switching is performed by selectively introducing/discharging high-pressure fluid (refrigerant) into/from the two working chambers by the pilot valves, and sliding the slide valve body in the left and right directions by a pressure difference between the two working chambers.

More specifically, the left and right pistons defining the two working chambers are integrally movably connected by a connecting body, and a spool is fitted or fixed to an opening formed in the connecting body, and the spool slides on a valve seat surface of a valve seat (valve seat member) provided with a plurality of ports (five ports pB to pF) by the connecting body in accordance with reciprocating movement of the piston caused by introduction/discharge of a high-pressure fluid (refrigerant) into/from the two working chambers. The slide valve body has two inner chambers (communication passages) for selectively communicating two adjacent ports among the plurality of ports, and the plurality of ports are selectively communicated with each other through the two inner chambers by the movement of the slide valve body, thereby switching the flow paths.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a flow path switching valve capable of improving sealing performance by making uniform a pressing load (distribution) applied to a seal portion.

In order to achieve the above object, a flow path switching valve according to the present invention basically includes: a cylinder-type housing having a valve chamber partitioned by a pair of pistons and opened with a port; a valve seat member that is provided in the housing and that has a valve seat surface on which a plurality of ports are arranged in the axial direction and open; a plurality of spool bodies that are disposed on the valve seat surface so as to be slidable in an axial direction, that have gaps of a predetermined size therebetween, that are arranged in an axial line direction, and that are each provided with a communication passage of a size that allows adjacent ports of the plurality of ports to communicate with each other; and a connecting body that connects the pair of pistons so as to be movable integrally, and slides the plurality of slide valves on the valve seat surface by the connecting body in accordance with reciprocating movement of the pair of pistons, wherein the plurality of ports selectively communicate with each other through the communication passages provided in the plurality of slide valves.

In a preferred aspect, the coupling body has a plurality of openings into which the plurality of slide valve bodies are fitted so as to be slidable in a direction perpendicular to the valve seat surface.

In another preferred mode, the clearance is located on a port between adjacent spool pieces in the middle of the flow path switching.

In another preferred embodiment, the gap is formed linearly.

In another preferred mode, the gap is formed in a curved shape.

In a more preferred aspect, the curved gap has the narrowest distance in a direction perpendicular to the axis.

In a more preferred aspect, an insertion portion extending in the axial direction is provided on one of the adjacent slide valve bodies, a semi-cylindrical outer cylinder portion extending in the axial direction and covering an outer periphery of the insertion portion is provided on the other of the adjacent slide valve bodies, and the curved gap is formed by the outer cylinder portion and the insertion portion.

In a more preferred aspect, the distance between the inner peripheral surface of the outer tube portion and the outer peripheral surface of the fitting portion is the narrowest at the curved gap.

In a more preferred aspect, the distance between the inner peripheral surface of the outer tube portion and the outer peripheral surface of the fitting portion is smaller than an axial gap formed between an end surface of the fitting portion and an end surface of the other spool and an axial gap formed between the end surface of the outer tube portion and the end surface of the one spool.

In the flow path switching valve according to the present invention, the plurality of slide valves are disposed in an axially slidable manner on valve seat surfaces in which the plurality of ports are aligned in the axial direction and open, and are disposed in an axially aligned manner with a predetermined gap therebetween, and the plurality of slide valves are each provided with a communication passage having a size that allows adjacent ports of the plurality of ports to communicate with each other. Therefore, although there is a possibility that the pressing load (distribution) applied to the seal portion may vary between the plurality of slide valve bodies, the pressing load (distribution) applied to the seal portion is substantially uniform in each slide valve body without being affected by (deformation of) the other slide valve bodies, and the sealing performance can be improved.

In addition, in this flow path switching valve, since a load is applied to the compressor when the discharge side (high pressure side) of the compressor is a closed circuit, a structure is generally adopted in which all ports are connected with a small area (small flow rate) when the slide valve body moves. However, in this case, when the flow rate (hereinafter, sometimes referred to as a bypass flow rate) flowing from the compressor discharge side (high pressure side) to the compressor suction side (low pressure side) becomes large, it is necessary to improve the capacity of the compressor.

In the flow path switching valve of the present invention, as described above, the plurality of slide valve elements are arranged in line in the axial direction with a gap of a predetermined size therebetween, and the gap is formed in a curved shape having a narrow portion. Therefore, the increase (amount) of the bypass flow rate can be minimized, and the sealing performance can be improved without increasing the capacity of the compressor, so that the influence on the operability can be reduced.

Drawings

Fig. 1 is a vertical sectional view showing a first embodiment of a flow path switching valve (six-way switching valve) according to the present invention.

Fig. 2 is a vertical cross-sectional view showing a flow path switching of the six-way switching valve shown in fig. 1.

Fig. 3 is an enlarged longitudinal sectional view showing a main portion of a portion a of fig. 2 in an enlarged manner.

Fig. 4 is a cross-sectional view along the line of sight U-U of fig. 3.

Fig. 5 is a vertical cross-sectional view showing a second embodiment of a flow path switching valve (six-way switching valve) according to the present invention.

Fig. 6 is a vertical cross-sectional view showing a middle of flow path switching of the six-way switching valve shown in fig. 5.

Fig. 7 is an enlarged longitudinal sectional view showing a main portion of a portion B of fig. 6 in an enlarged manner.

Fig. 8 is a cross-sectional view along the line of sight V-V of fig. 7.

Fig. 9(a) and (B) are schematic configuration diagrams each showing an example of a heat pump type cooling and heating system using a six-way switching valve as a flow path switching valve, fig. 9(a) is a schematic configuration diagram showing an example of a heat pump type cooling and heating system using a six-way switching valve as a flow path switching valve during a cooling operation, and fig. 9(B) is a schematic configuration diagram showing an example of a heat pump type cooling and heating system using a six-way switching valve as a flow path switching valve during a heating operation.

Description of the symbols

1 six-way switching valve (flow path switching valve) (first embodiment)

2 six-way switching valve (flow path switching valve) (second embodiment)

8 four-way pilot valve

9 main valve

10 connected body

12. 13 opening

14. 15 circular opening

21. 31 slide valve core

22. 32 sealing surface

25. 35U-shape turning communication path (communication path)

26 outer tube part (second embodiment)

36 fitting part (second embodiment)

80 casing

81 valve seat member

82 seat surface

83 valve chamber

84A, 84B pistons

86A, 86B studio

87A, 87B cover member

G1 gap between slide valve elements (first embodiment)

G2 gap between slide valve elements (second embodiment)

Detailed Description

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

[ first embodiment ]

Fig. 1 is a vertical sectional view showing a first embodiment of a six-way switching valve as a flow path switching valve of the present invention.

Note that in the present specification, the description of the positions and directions such as up and down, left and right, front and back, and the like is given for convenience in the drawings in order to avoid the description becoming complicated, and is not limited to the positions and directions in a state of being actually incorporated in the heat pump type air conditioning system or the like.

In the drawings, for easy understanding of the invention, gaps formed between members, separation distances between members, and the like may be drawn larger than the sizes of the respective constituent members for convenience of drawing.

The six-way switching valve 1 of the illustrated embodiment is, for example, a slide-type six-way switching valve used as the six-way switching valve 180 in the heat pump type cooling and heating system 100 shown in fig. 9(a) and (B), and basically includes a main valve 9 having two slide valve bodies 21 and 31 built therein and a four-way pilot valve 8. The six ports provided in the six-way switching valve 1 according to the present embodiment are denoted by the same reference numerals as those of the ports pA to pF of the six-way switching valve 180 (see patent document 1 and the like).

The main valve 9 includes a cylinder-shaped (cylindrical) housing 80, a valve seat member 81 provided in the housing 80, a port pB, a port pC, a port pD (low-pressure port), a port pE, and a port pF, which are opened in a flat and smooth valve seat surface 8b formed on an upper surface of the valve seat member 81 and are arranged in a lateral direction (a length of the housing 80 or an axis O direction), and a pair of slide spools 21 and 31 having a rectangular cross section and a substantially inverted bowl shape in a plan view (that is, a symmetrical shape on a surface perpendicular to the axis O) which are arranged on the valve seat surface 82 so as to be slidable in the lateral direction.

The slide valve bodies 21 and 31 are made of, for example, synthetic resin and arranged in a lateral direction. The slide valve body 21 disposed on the left side has a seal surface 22 abutting on the valve seat surface 82, and a U-turn communication passage 25 is provided in the slide valve body 21 so as to selectively communicate three ports pB to pD of the five ports pB to pF, in other words, so as to establish a first state in which the adjacent port pC communicates with the port pD and a second state in which the adjacent port pC communicates with the port pB.

Similarly, the slide valve body 31 disposed on the right side has a seal surface 32 abutting on the seat surface 82, and a U-turn communication passage 35 is provided in the slide valve body 31 so as to selectively communicate three ports pD to pF of the five ports pB to pF, in other words, so as to establish a first state in which the adjacent port pE communicates with the port pF and a second state in which the adjacent port pE communicates with the port pD.

Lid members 87A, 87B are airtightly fixed to both ends of the housing 80, and the housing 80 is airtightly partitioned by two (a pair of) left and right packing pistons 84A, 84B to define a valve chamber 83 and two working chambers 86A, 86B. A port p0 (high pressure port) connected to the discharge side of the compressor opens in the valve chamber 83 (a position facing the central port pD in the illustrated example).

The two pistons 84A and 84B are connected to each other so as to be movable integrally by a connecting body 10 in the form of a horizontally long rectangular plate. In the coupling body 10, the two slide valve bodies 21 and 31 are slidable in a lower side or a vertical direction (a direction perpendicular to the valve seat surface 82), and rectangular openings 12 and 13 having a size (two are formed so as to be arranged laterally in a left-right direction) are formed so as to be fitted to each other so as to be slightly movable in the left-right direction. The two slide valve bodies 21 and 31 are fitted into the openings 12 and 13, respectively, so that a gap (gap) G1 having a predetermined size is provided therebetween, and are arranged laterally in the left-right direction. In this example, the gap (gap) G1 is formed in a substantially straight line shape along the vertical direction (the direction perpendicular to the axis O) between the right end portion (surface) of the spool 21 and the left end portion (surface) of the spool 31. Each of the spool members 21, 31 is pushed toward the respective openings 12, 13 of the coupling body 10 by the reciprocating movement of the two pistons 84A, 84B, and slides between a right end position (first state) (at the time of cooling operation shown in fig. 9 (a)) where the port pD (low pressure port) and the port pC are communicated via the U-turn communication passage 25 formed inside the spool member 21 and the port pF and the port pE are communicated via the U-turn communication passage 35 formed inside the spool member 31, and a left end position (second state) (at the time of heating operation shown in fig. 9 (B)) where the port pB and the port pC are communicated via the U-turn communication passage 25 formed inside the spool member 21 and the port pD (low pressure port) and the port pE are communicated via the U-turn communication passage 35 formed inside the spool member 31. Fig. 1 shows a second state (during the heating operation shown in fig. 9B).

Further, in the coupling body 10, a circular opening 14 (having substantially the same diameter as the port pB) is formed on the left side of the opening 12, that is, on a portion located substantially directly above the leftmost port pB when the spools 21 and 31 are at the right end positions (first state), and a circular opening 15 (having substantially the same diameter as the port pF) is formed on the right side of the opening 13, that is, on a portion located substantially directly above the rightmost port pF when the spools 21 and 31 are at the left end positions (second state).

In the main valve 9, the two working chambers 86A and 86B are selectively connected to the compressor discharge side (high pressure side) and the compressor suction side (low pressure side) via the four-way pilot valve 8 and the narrow tubes #1 to #4, and the operating modes (cooling operation and heating operation) are switched in the heat pump type cooling and heating system shown in fig. 9 a and B by moving the pistons 84A and 84B by the pressure difference between the two working chambers 86A and 86B and sliding the slide valve bodies 21 and 31 on the valve seat surface 82 in association with this (via the respective openings 12 and 13 of the coupling body 10) to switch the flow paths.

At the time of this flow path switching (at the time of switching of the operation mode), the (sealing surfaces 22, 32 of the) slide valve bodies 21, 31 fitted to the (respective openings 12, 13 of the) coupling body 10 are constantly pressed against the seat surface 82 of the seat member 81 by the pressure difference between the outer sides thereof (the valve chamber 83 side where the port pA is opened) and the inner sides thereof (the U-turn communication passages 25, 35).

Here, in the six-way switching valve 1 of the present embodiment, at the time of the flow path switching as described above, the respective slide valve bodies 21, 31 slide on the valve seat surface 82 with the gap G1 of a predetermined size therebetween, and as shown in enlarged views in fig. 3 and 4, the gap G1 is located at the port pD (low pressure port) between the adjacent slide valve bodies 21, 31 during the flow path switching.

In fig. 1 to 3, the respective slide valves 21 and 31 are shown to be positioned closer to the centers of the respective openings 12 and 13, but actually, when switching from the right end position (first state) to the left end position (second state), the respective slide valves 21 and 31 are positioned at the right positions (more than the centers) of the respective openings 12 and 13, and when switching from the left end position (second state) to the right end position (first state), the respective slide valves 21 and 31 are positioned at the left positions (more than the centers) of the respective openings 12 and 13.

Therefore, during the flow path switching (when the spool 21, 31 is moved), all (six) ports pA to pF are communicated via a gap formed between the left end portion of the left spool 21 and (the port pB of) the valve seat member 81, a U-turn communication passage 25 formed inside the spool 21, a U-turn communication passage 35 formed inside the spool 31, a gap between the right end portion of the right spool 31 and (the port pF of) the valve seat member 81, a (substantially linear) gap G1 formed between the spools 21, 31, and the like, as indicated by broken arrows in fig. 2. The communication passage and the flow rate flowing through the communication passage (from the compressor discharge side (high pressure side) to the compressor suction side (low pressure side)) are referred to as a bypass passage and a bypass flow rate.

As described above, in the six-way switching valve (flow path switching valve) 1 of the present embodiment, the plurality of (two) slide valve bodies 21 and 31 are disposed slidably in the axis O direction on the valve seat surface 82 in which the plurality of ports (five ports pB to pF) are arranged and opened in the axis O direction, are disposed in the axis O direction with the gap (gap) G1 of a predetermined size therebetween, and are provided with the U-turn communication passages 25 and 35 of a size to communicate with the adjacent ports of the plurality of ports (five ports pB to pF), respectively. Therefore, although there is a possibility that the pressing load (distribution) applied to the seal portion may vary between the plurality of spools 21, 31, the pressing load (distribution) applied to the seal portion is substantially uniform in each of the spools 21, 31 without being affected by (deformation of) the other spool, and the sealing performance can be improved.

[ second embodiment ]

Fig. 5 is a vertical cross-sectional view showing a six-way switching valve as a flow path switching valve according to a second embodiment of the present invention.

The six-way switching valve 2 of the second embodiment is different from the six-way switching valve 1 of the first embodiment in the configuration of a gap (clearance) portion mainly interposed between the slide valve bodies 21 and 31, and the other configurations are substantially the same. Therefore, the same reference numerals are given to the portions corresponding to the respective portions of the six-way switching valve 1 of the first embodiment, and redundant description is omitted, and the following description focuses on the differences.

The six-way switching valve 2 of the illustrated embodiment is, for example, a slide-type six-way switching valve used as the six-way switching valve 180 in the heat pump type cooling and heating system 100 shown in fig. 9(a) and (B), similar to the six-way switching valve 1 of the first embodiment, but in this example, a flat (more specifically, a rectangular insertion portion 36 that is longer in the front-rear direction (vertical direction with respect to the paper surface of fig. 5) than the end diameter (diameter) of the port pD in the front-rear direction) when viewed from the side that extends toward the left side (slide valve 21 side) is (integrally) provided so as to protrude from the left end lower portion of the slide valve 31 on the right side (in other words, the portion that faces the adjacent slide valve 21 and that is in sliding contact with the valve seat surface 82).

Further, a half-cylindrical outer cylinder portion 26 (in detail, a half-cylindrical shape which is flat in side view and which is open at the lower side) which extends toward the right side (the side of the spool 31) and covers the outer periphery of the fitting portion 36 is (integrally) provided so as to protrude from a right end lower portion of the left spool 21 (in other words, a portion facing the adjacent spool 31).

In a state where the fitting portion 36 is inserted into the outer tube portion 26 (with a gap therebetween) (also referred to as a joint structure), the two slide valve bodies 21 and 31 are fitted into the openings 12 and 13 of the coupling body 10 from below, so that a curved gap (gap) G2 is formed between the adjacent slide valve bodies 21 and 31 as shown in fig. 7 and 8 in an enlarged manner. The curved shape is a shape in which two L-shaped curves are continued as indicated by a broken-line arrow in fig. 7.

In fig. 5 to 7, as in fig. 1 to 3, the slide valves 21 and 31 are shown so as to be positioned near the centers of the openings 12 and 13, but actually, when switching from the right end position (first state) to the left end position (second state), the slide valves 21 and 31 are positioned at the right positions (more than the centers) of the openings 12 and 13, and when switching from the left end position (second state) to the right end position (first state), the slide valves 21 and 31 are positioned at the left positions (more than the centers) of the openings 12 and 13.

Therefore, in the six-way switching valve 2 of the second embodiment as well, as in the six-way switching valve 1 of the first embodiment described above, during the flow path switching (when the slide valve bodies 21, 31 are moved), all (six) ports pA to pF are communicated with each other via a gap formed between the left end portion of the slide valve body 21 on the left side and (the port pB of) the valve seat member 81, a U-turn communication passage 25 formed inside the slide valve body 21, a U-turn communication passage 35 formed inside the slide valve body 31, a gap formed between the right end portion of the slide valve body 31 on the right side and (the port pF of) the valve seat member 81, a (curved) gap G2 formed between the slide valve bodies 21, 31, and the like as indicated by broken arrows in fig. 6.

In this example, the shape and size of each portion (in particular, the lateral direction gap parallel to the axis O) of the curved gap G2 is set so that the gap (the gap in the direction perpendicular to the axis O) G2a formed between the outer peripheral surface (the surface parallel to the axis O, in particular, the upper surface 36a of the fitting portion 36) of the fitting portion 36 and the inner peripheral surface (the surface parallel to the axis O, in particular, the lower surface 26a of the outer tube portion 26) of the outer tube portion 26 is smaller than the gap (the lateral direction gap parallel to the axis O) G2c formed between the left end surface 36b (the surface perpendicular to the axis O) of the fitting portion 36 and the right end surface 21b (the surface perpendicular to the axis O) of the slide valve body 21 and the gap (the lateral direction gap parallel to the axis O) G2b formed between the right end surface 26b (the surface perpendicular to the axis O) of the outer tube portion 26 and the left end surface 31b (the surface perpendicular to the axis O) of the slide valve body 31 are set to be smaller than the, see fig. 7 and 8). In other words, the gap (the interval in the direction perpendicular to the axis O) G2a is the narrowest in the curved gap G2.

For example, in the six-way switching valve 1 according to the first embodiment described above, the gap G1 between the slide valve bodies 21 and 31 is formed in a substantially straight line shape along the vertical direction (the direction perpendicular to the axis O), and when the gap G1 is to be always secured, the gap G1 is set to be larger than a minimum gap required in the left-right direction (specifically, a gap between (the left and right ends of) the slide valve bodies 21 and 31 and (the left and right ends of) the openings 12 and 13 of the coupling body 10) (for example, about 1mm) which is required when the slide valve bodies 21 and 31 move, and therefore, the bypass flow rate (see fig. 2) is increased, and it is necessary to improve the compressor performance.

On the other hand, in the six-way switching valve 2 according to the second embodiment, the clearance G2 between the slide valve bodies 21 and 31 can be formed in a curved shape and the clearance G2 can be substantially narrowed by adopting the above configuration, so that the bypass flow rate can be reduced (see fig. 6), and improvement in the compressor performance is not required. For example, since the deformation (inclination) of the spool 21, 31 during sealing is about 0.01mm and valve leakage occurs, the gap (the interval in the direction perpendicular to the axis O) G2a in the gap G2 may be about 0.1 to 0.3mm (about ten to several tens of times of 0.01 mm), and the gap can be significantly reduced with respect to a required minimum gap in the left-right direction (specifically, a required gap (e.g., about 1mm) between the spool 21, 31 and the opening 12, 13 of the coupling body 10, which is required when the spool 21, 31 moves.

As described above, in the six-way selector valve 2 according to the second embodiment, the plurality of (two) slide valve bodies 21 and 31 are disposed slidably in the axis O direction on the valve seat surface 82 in which the plurality of ports (five ports pB to pF) are arranged and opened in the axis O direction, are disposed in the axis O direction with the gap (gap) G2 of a predetermined size therebetween, and are provided with the U-turn communication passages 25 and 35 of a size to communicate with the adjacent ports among the plurality of ports (five ports pB to pF), respectively. Therefore, although there is a possibility that the pressing load (distribution) applied to the seal portion may vary between the plurality of spools 21, 31, the pressing load (distribution) applied to the seal portion is substantially uniform in each of the spools 21, 31 without being affected by (deformation of) the other spool (i.e., without being in contact with the other spool), and the sealing performance can be improved.

In the six-way switching valve 2, since a load is applied to the compressor when the compressor discharge side (high pressure side) is a closed circuit, a structure is generally adopted in which all ports are connected with a small area (small flow rate) when the slide valve bodies 21 and 31 move. However, in this case, when the flow rate (bypass flow rate) flowing from the compressor discharge side (high pressure side) to the compressor suction side (low pressure side) becomes large, it is necessary to improve the capacity of the compressor.

In the six-way switching valve 2 according to the second embodiment, as described above, the plurality of (two) slide valve bodies 21 and 31 are arranged in line in the axis O direction with the gap (gap) G2 having a predetermined size therebetween, and the gap G2 is formed in a curved shape having the narrow portion (gap G2 a). Therefore, the increase (amount) of the bypass flow rate can be minimized, and the sealing performance can be improved without increasing the capacity of the compressor, so that the influence on the operability can be reduced.

In the first and second embodiments, the six-way switching valve in the heat pump type air-conditioning system was described as an example of the flow path switching valve, but the present invention can be applied to a multi-way switching valve other than the six-way switching valve in which the flow path is switched by a slide valve. In this case, the number of the slide valve bodies disposed in the valve chamber 83 may be two or more.

In the six- way switching valves 1 and 2 of the first and second embodiments, the four-way pilot valve 8 is used to drive the slide valve bodies 21 and 31 in the valve chamber 83, but for example, a motor may be used instead of the four-way pilot valve 8 to drive the slide valve bodies 21 and 31 in the valve chamber 83.

The six- way switching valves 1 and 2 according to the first and second embodiments can be incorporated not only in the heat pump type cooling and heating system but also in other systems, devices, and facilities.