CN109578616B

CN109578616B - Six-way switching valve

Info

Publication number: CN109578616B
Application number: CN201810876007.8A
Authority: CN
Inventors: 田渕健资; 藤田尚敬; 森田纪幸
Original assignee: Fujikoki Corp
Current assignee: Fujikoki Corp
Priority date: 2017-09-29
Filing date: 2018-08-03
Publication date: 2022-07-19
Anticipated expiration: 2038-08-03
Also published as: CN109578616A; JP6515163B2; JP2019065895A

Abstract

The invention provides a six-way switching valve which makes the valve difficult to leak and effectively restrains pressure loss. Three ports (pB, pA, pF) are opened in parallel in the direction of an axis (O), and on the opposite side of the three ports with respect to the axis, three other ports (pC, pD, pE) are opened in parallel in the direction of the axis, and a first U-shaped steering passage (16A) and a second U-shaped steering passage (16B) are provided in a main spool (15), and the main spool is moved in a main valve chamber, whereby a first communication state and a second communication state can be selectively obtained. The main valve body has a cylindrical first spool (15A) and a second spool (15B) having a fitting projection (15B) fitted slidably into the first spool on the left side surface, and the fitting projection is fitted into the first spool, whereby a first U-shaped steering passage is defined by the inner peripheral surface of the first spool and the left end surface of the fitting projection.

Description

Six-way switching valve

Technical Field

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

Background

In general, a heat pump type cooling and heating system such as a room air conditioner or a car air conditioner includes a flow path switching valve as a 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.

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

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/heating system 100 illustrated in the figure switches the operation modes (cooling operation and heating operation) by the six-way switching valve 180, and basically includes: the compressor 110, the outdoor heat exchanger 120, the indoor heat exchanger 130, the expansion valve 150 for cooling, and the expansion valve 160 for heating are disposed with a six-way switching valve 180 having six ports pA, pB, pC, pD, pE, and pF 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 introduced from the port pA of the six-way switching valve 180 into the outdoor heat exchanger 120 via the port pB, exchanges heat with outdoor air, condenses therein, and is introduced into the expansion valve 150 for cooling as a high-pressure two-phase gas-liquid or liquid-phase refrigerant. 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 subjected to heat exchange (cooling) with the indoor air and evaporated therein, and the low-temperature low-pressure refrigerant from the indoor heat exchanger 130 is returned from the port pC of the six-way switching valve 180 to the intake side of the compressor 110 via the port pD.

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 introduced from the port pA of the six-way switching valve 180 into the indoor heat exchanger 130 via the port pF, is condensed by heat exchange (heating) with the indoor air, and is introduced into the heating expansion valve 160 as a high-pressure two-phase gas-liquid or liquid-phase 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 exchanging heat with the outdoor air, and the low-temperature low-pressure refrigerant from the outdoor heat exchanger 120 returns from the port pE of the six-way switching valve 180 to the suction side of the compressor 110 through the port pD.

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

Documents of the prior art

Patent literature

Patent document 1: japanese patent laid-open publication No. 8-170864

Problems to be solved by the invention

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

That is, in the six-way switching valve of the sliding type disclosed in patent document 1, since five ports pB to pF of the six ports pA to pF are provided in parallel in the axial direction, the main valve seat and the sliding type main valve body (in the axial direction) provided with the five ports pB to pF become long, and it is difficult to secure surface accuracy (flatness) of the seat surface of the main valve seat and the sealing surface of the sliding type main valve body which slidably abut against the sliding type main valve body, and there is a possibility that initial leakage and durability deterioration cause leakage (valve leakage) to increase.

In addition, in the main valve casing having a small inner volume, the high-pressure fluid (refrigerant) collides with the inner wall surface and the like, and the flow direction thereof largely changes in a crank shape, so that there is a problem in that the pressure loss increases.

In addition to the above, in the conventional flow path switching valve, particularly in the flow path switching valve used in the heat pump type cooling and heating system, a high-temperature and high-pressure refrigerant (a refrigerant flowing from the port pA to the port pB and from the port pA to the port pF) and a low-temperature and low-pressure refrigerant (a refrigerant flowing from the port pC to the port pD and from the port pE to the port pD) flow in close proximity in the main valve housing. Specifically, a high-temperature high-pressure refrigerant and a low-temperature low-pressure refrigerant flow through the main valve seat to the adjacent port pB and port pC during cooling operation and flow through the main valve seat to the adjacent port pF and port pC during heating operation, but the main valve seat provided with each port is generally made of a metal having high thermal conductivity, and therefore the amount of heat exchange (i.e., heat loss) therebetween increases, and there is a problem that the system efficiency deteriorates.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide a six-way selector valve which can effectively suppress pressure loss while preventing valve leakage.

Another object of the present invention is to provide a flow path switching valve that can reduce heat loss and improve the efficiency of a heat pump type cooling and heating system when used in an environment where a high-temperature high-pressure fluid and a low-temperature low-pressure fluid flow, such as a heat pump type cooling and heating system.

Means for solving the problems

To achieve the above object, a six-way selector valve according to the present invention basically comprises: a cylindrical main valve housing defining a main valve chamber; a port, wherein six ports are provided in total in the main valve housing; and a sliding type main valve element disposed in the main valve chamber so as to be movable in an axial direction, the main valve element being provided with a plurality of communication passages for selectively communicating the ports, and the main valve element being movable so as to switch between the ports that communicate with each other, wherein three ports are opened in the axial direction in parallel to the main valve chamber, and the other three ports are opened in the axial direction in parallel to the main valve chamber on a side opposite to the axial direction of the three ports, the main valve element includes a low-pressure side sliding valve element having a fitting projection slidably fitted into the high-pressure side sliding valve element on one side, and a cylindrical high-pressure side sliding valve element having the fitting projection slidably fitted into the high-pressure side sliding valve element on the high-pressure side sliding valve element so as to pass through an inner peripheral surface of the high-pressure side sliding valve element and an end surface of the fitting projection, a high-pressure-side U-turn passage that selectively communicates two of the three ports and into which a relatively high-pressure fluid is introduced is partitioned, the high-pressure-side spool and the low-pressure-side spool are movable integrally in the axial direction, and a low-pressure-side U-turn passage that selectively communicates two of the other three ports and into which a relatively low-pressure fluid is introduced is opened on the other side surface of the low-pressure-side spool and that selectively communicates the other three ports and that moves the main spool in the main valve chamber, so that a plurality of communication states can be selectively obtained: communicating two of the three ports via the high pressure side U-turn passage, two of the other three ports via the low pressure side U-turn passage, and one of the other three ports with one of the other three ports through the main valve housing.

In a preferred aspect, an annular seal member is disposed between the high-pressure side spool and the fitting projection of the low-pressure side spool.

In another preferred aspect, an outer shape of an annular seal surface of the high-pressure side spool provided on the main valve seat side of the three ports is smaller than an outer shape of the seal member.

In another preferred aspect, an inner flange-shaped portion is provided on an inner periphery of an end portion of the high-pressure side sliding spool on the main valve seat side where the three ports are provided, and the annular sealing surface is formed on an end surface of the inner flange-shaped portion on the main valve seat side.

In another preferred aspect, an urging member that urges the high-pressure side spool and the low-pressure side spool in opposite directions is disposed between the high-pressure side spool and the low-pressure side spool.

In another preferred aspect, the biasing member is disposed outside the sealing member.

In another preferred aspect, a passage area of the low-pressure side U-shaped steering passage is larger than a passage area of the high-pressure side U-shaped steering passage.

In another preferred aspect, a guide surface formed of a bowl-shaped recess is formed on an end surface of the fitting convex portion, and the guide surface smoothes a flow of the high-pressure fluid in the high-pressure-side U-turn passage.

In another preferred aspect, the main valve housing includes a first operation chamber and a second operation chamber having variable volumes, the first operation chamber and the second operation chamber being partitioned by a pair of a first piston and a second piston and selectively introducing and discharging a high-pressure fluid, the main valve body being arranged to be movable in an axial direction in association with the first piston and the second piston, and the main valve body being moved in the main valve chamber by controlling introduction and discharge of the high-pressure fluid into and from the first operation chamber and the second operation chamber and moving the first piston and the second piston.

In another preferred aspect, the first piston and the second piston are connected to each other so as to be movable integrally by a connecting body formed by one or more plate members arranged in a direction orthogonal to a seat surface of a main valve seat provided with the port, and the main valve body is supported by the connecting body so as to be slidable in a direction orthogonal to the seat surface of the main valve seat and moves in accordance with the reciprocal movement of the first piston and the second piston.

In another preferred aspect, the coupling body is provided with a stopper portion for restricting movement of the main valve element in the axial direction.

In another preferred form, the stopper abuts against the main valve housing.

Effects of the invention

In the six-way switching valve of the present invention, three ports are opened to the main valve chamber side by side in the axial direction, and on the opposite side of the three ports with respect to the axial line, the other three ports are opened to the main valve chamber side by side in the axial direction, a high-pressure side U-turn passage that selectively communicates two of the three ports and into which relatively high-pressure fluid is introduced and a low-pressure side U-turn passage that selectively communicates two of the other three ports and into which relatively low-pressure fluid is introduced are provided in the main spool, the main spool is moved within the main valve chamber, and thereby a plurality of communication states (flow passages) can be obtained: two of the three ports are caused to communicate via the high pressure side U-turn passage, two of the other three ports are caused to communicate via the low pressure side U-turn passage, and the other one of the three ports is caused to communicate with the other one of the other three ports through the main valve housing. Therefore, compared to a six-way selector valve using a conventional sliding main spool, the main valve seat provided with a port and the main spool can be shortened (in the axial direction), and therefore, it is easy to ensure the surface accuracy (flatness) of the seat surface of the main valve seat and the sealing surface of the main spool, to suppress valve leakage, and to reduce pressure loss because a fluid (for example, a high-pressure fluid (refrigerant)) flows through the U-shaped diversion passage.

In addition to the above, when the six-way switching valve of the present embodiment is used in an environment where a high-temperature and high-pressure refrigerant and a low-temperature and low-pressure refrigerant flow, such as a heat pump type cooling and heating system, and the like, the high-pressure side U-turn passage through which the high-temperature and high-pressure refrigerant flows and the low-pressure side U-turn passage through which the low-temperature and low-pressure refrigerant flows are provided to be separated far apart from each other without passing through a metal main valve seat, for example, and therefore, compared to a conventional structure in which a high-temperature and high-pressure refrigerant and a low-temperature and low-pressure refrigerant flow in a close state through a metal main valve seat, the amount of heat exchange therebetween (i.e., heat loss) can be significantly reduced, and therefore, the effect of improving the efficiency of the system can also be obtained.

In the six-way selector valve according to the present invention, the main valve element includes a cylindrical high-pressure side spool and a cylindrical low-pressure side spool, the low-pressure side spool has an engaging projection slidably fitted into the high-pressure side spool on one side surface (the side surface on the high-pressure side spool side), and the engaging projection is fitted into the high-pressure side spool, so that the high-pressure side U-shaped steering passage is defined by the inner peripheral surface of the high-pressure side spool and the end surface of the engaging projection, and the low-pressure side spool is pressed (pressure-contacted) against the main valve seat having the port by (the fluid pressure of) the high-pressure fluid introduced into the high-pressure side U-shaped steering passage. Therefore, the valve leakage can be more effectively suppressed while suppressing the body size (particularly, the size in the direction orthogonal to the axis) of the main spool.

Further, since the outer shape of the annular seal surface of the high-pressure side spool on the main valve seat side provided with the three ports is smaller than the outer shape of the seal member disposed between the fitting convex portions of the high-pressure side spool and the low-pressure side spool, the high-pressure side spool is pressed (pressure-contacted) against the main valve seat provided with the ports by the differential pressure acting on the high-pressure side spool due to the difference in the pressure receiving area of the high-pressure side spool, and thus valve leakage can be suppressed more effectively.

The problems, structures, and operational effects other than those described above will be more apparent from the following embodiments.

Drawings

Fig. 1 is a vertical sectional view showing a first communication state (during cooling operation) of an embodiment of the six-way switching valve according to the present invention.

Fig. 2 is a vertical cross-sectional view showing a second communication state (during heating operation) of the six-way switching valve according to the embodiment of the present invention.

Fig. 3 is an enlarged longitudinal sectional view of a main portion of the six-way switching valve shown in fig. 1.

Fig. 4 is a cross-sectional view taken along the line U-U arrow of fig. 1.

Fig. 5 is a perspective view showing a main valve and a coupling body of an embodiment of the six-way selector valve according to the present invention.

Fig. 6 is an enlarged view of the four-way pilot valve used in the six-way switching valve according to the present invention, where (a) is a vertical sectional view showing a first communication state (during cooling operation) (when energization is off), and (B) is a vertical sectional view showing a second communication state (during heating operation) (when energization is on).

Fig. 7 is an enlarged longitudinal sectional view of a main portion of another example of the six-way switching valve shown in fig. 1.

Fig. 8 is a longitudinal sectional view showing an enlarged principal part of another example of the six-way switching valve shown in fig. 1.

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

Description of the symbols

1 six-way switching valve

10 six-way valve body

11 main valve casing

11A upper end side cover part

11B lower end side cover part

11a first piston part

11b second piston part

11c carcass part

12 main valve chamber

13 first main valve seat (valve seat)

14 second main valve seat (valve seat)

15 main valve core

15A first sliding valve core (high pressure side sliding valve core)

15B second sliding valve core (low pressure side sliding valve core)

15a inner flange-like portion of the first spool

15b fitting projection of second spool

15c guide surface of second spool

15e concave surface

16A first U-shaped turning passage (high pressure side U-shaped turning passage) (communication passage)

16B second U-shaped turning passage (low pressure side U-shaped turning passage) (communication passage)

18O-ring (Ring sealing member)

21 first piston

22 second piston

25 connected body

25A, 25B a pair of connecting plates

25a connecting plate part

25aa offset plate section

25ab butt plate part

25b mounting foot

25c support plate part

Stopper of 25s connected body

31 first action chamber

32 second motion chamber

90 four-way pilot valve

pA, pB, pC, pD, pE, pF ports

Detailed Description

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

Fig. 1 and 2 are longitudinal sectional views showing an embodiment of a six-way switching valve according to the present invention, fig. 1 being a view showing a first communication state (during a cooling operation), and fig. 2 being a view showing a second communication state (during a heating operation).

In the present specification, the expressions indicating the positions and the directions such as the up-down direction, the left-right direction, the front-back direction, and the like are provided for convenience in the drawings in order to avoid the complexity of the description, and are not limited to the positions and the directions in the state where the heat pump type air-cooling and heating system or the like is actually incorporated.

In the drawings, the gaps formed between the members, the distances between the members, and the like are drawn to be larger or smaller than the dimensions of the respective components in order to facilitate understanding of the present invention.

The six-way switching valve 1 of the illustrated embodiment is a sliding type configuration used as the six-way switching valve 180 in the heat pump type air-cooling and heating system shown in fig. 9(a) and (B), for example, and basically includes: a cylinder type six-way valve body 10 and a single electromagnetic four-way pilot valve 90 as a pilot valve. The six ports of the six-way selector valve 1 of the present embodiment are denoted by the same reference numerals as those of the six-way selector valve 180, corresponding to the ports pA to pF.

[ Structure of six-way valve body 10 ]

The six-way valve body 10 has a cylindrical main valve housing 11 made of metal such as brass or stainless steel, and a first operation chamber 31, a first piston 21, a main valve chamber 12, a second piston 22, and a second operation chamber 32 are arranged in this main valve housing 11 in this order from one end side (upper end side). In the first and

second pistons

21 and 22, a spring-loaded packing is attached to an inner circumferential surface of the main valve housing 11 in pressure contact with an outer circumferential portion thereof so as to airtightly partition the main valve housing 11.

More specifically, the main valve housing 11 has a body 11c with a large diameter, a center hole is provided in a thick circular plate-shaped upper connection cap 11d airtightly attached to an upper end opening of the body 11c, a first piston portion 11a made of a pipe member (with a small diameter) is airtightly fixed to the center hole by brazing or the like, and the first piston 21 is disposed in the first piston portion 11 a. Similarly, a center hole is provided in a thick-walled disk-shaped lower connecting cap 11e airtightly attached to the lower end opening of the body portion 11c, a second piston portion 11b made of a (smaller-diameter) pipe member is airtightly fixed to the center hole by brazing or the like, and the second piston 22 is disposed in the second piston portion 11 b.

A thin disc-shaped upper end cap member 11A is hermetically fixed to the upper end of (the first piston portion 11A of) the main valve housing 11 by brazing or the like, the upper end cap member 11A defines a first variable capacity operating chamber 31, a thin disc-shaped lower end cap member 11B is hermetically fixed to the lower end of (the second piston portion 11B of) the main valve housing 11 by brazing or the like, and the lower end cap member 11B defines a second variable capacity operating chamber 32. Ports p11 and p12 for introducing and discharging high-pressure fluid (refrigerant) into and from the first working chamber 31 and the second working chamber 32 are respectively attached to (the centers of) the upper end-side cover member 11A and the lower end-side cover member 11B.

A total of six ports are provided in (the main valve chamber 12 of) the main valve housing 11.

More specifically, a first main valve seat (valve seat) 13 made of, for example, metal and having a flat surface (right surface) is airtightly fixed to (an inner periphery of) a body portion 11c of the main valve housing 11 at a left center of the main valve chamber 12 by brazing or the like, and three ports (a port pB, a port pA, and a port pF in order from an upper end side) formed of pipe joints extending leftward are longitudinally aligned (aligned in the direction of the axis O) and opened at substantially equal intervals at the valve seat surface of the first main valve seat 13.

Further, at the right center of the main valve chamber 12 (a position facing the first main valve seat 13, in other words, a position located on the opposite side of the axis O from the first main valve seat 13), a second main valve seat (valve seat) 14 made of, for example, metal having a flat seat surface (left surface) is airtightly fixed to (the inner periphery of) the body portion 11c of the main valve housing 11 by brazing or the like, and three ports (port pC, port pD, port pE in order from the upper end side) formed of pipe joints extending rightward are vertically aligned (aligned in the axis O direction) and opened at substantially equal intervals at the seat surface of the second main valve seat 14.

The ports (port pB, port pA, port pF) provided in the first main valve seat 13 and the ports (port pC, port pD, port pE) provided in the second main valve seat 14 are set at positions opposite to each other (on the opposite side with respect to the axis O), and in this example, the diameters of the ports pA to pF provided in the first main valve seat 13 and the second main valve seat 14 are set to be substantially the same.

In the main valve chamber 12, specifically, in the body portion 11c of the main valve housing 11, a sliding type main valve element 15 having a race-track-shaped annular seal surface and a rectangular cross section is disposed movably in the axis O direction (vertical direction), and both side surfaces (left and right surfaces) of the main valve element 15 are slidably abutted against seat surfaces of the first main valve seat 13 and the second main valve seat 14, respectively. In this example, the dimensions of the main spool 15 in the left-right direction and the front-rear direction are equal to or slightly larger than the outer diameters of the first piston portion 11a and the second piston portion 11b of the main valve housing 11.

The main valve element 15 is made of, for example, synthetic resin, and basically includes two components: a first spool (high-pressure side spool) 15A on the first main valve seat 13 side (left side) and a second spool (low-pressure side spool) 15B on the second main valve seat 14 side (right side).

The first spool 15A has a cylindrical shape, and an inner flange-shaped portion 15A defining an opening of a size capable of selectively communicating two adjacent ports (port pB and port pA, or port pA and port pF) among three ports (port pB and port pA, or port pA and port pF) that are opened in the seat surface of the first main valve seat 13 is provided so as to protrude from the inner periphery (inward) of the left end portion (the end portion on the opposite side to the second spool 15B). The left end surface (end surface on the first main valve seat 13 side) of the inner flange-shaped portion 15a is the annular seal surface that slidably abuts against the seat surface of the first main valve seat 13.

On the other hand, a second U-shaped turning passage (low-pressure side U-shaped turning passage) (communication passage) 16B constituted by a bowl-shaped recess is opened on the right surface side (the side opposite to the first spool 15A side) of the second spool 15B, the size of the second U-shaped turning passage 16B is such a size that two ports (port pC and port pD, or port pD and port pE) adjacent to each other among the three ports opened in the seat surface of the second main valve seat 14 can be selectively communicated, and a fitting convex portion 15B having an outer shape substantially the same as or slightly smaller than the inner shape of the cylindrical first spool 15A is extended (leftward) on the left surface (the side surface on the first spool 15A side) of the second spool 15B.

The fitting convex portion 15B of the second spool 15B is slidably fitted (with the O-ring 18 interposed between the fitting convex portion 15B and the first spool 15A) into (the right side portion of) the cylindrical first spool 15A, so that a first U-shaped turning passage (high-pressure side U-shaped turning passage) (communication passage) 16A is formed by the inner peripheral surface of the first spool 15A and the left end surface of the fitting convex portion 15B, the first U-shaped turning passage 16A can selectively communicate two adjacent ports (port pB and port pA, or port pA and port pF) of the three ports opening in the seat surface of the first main valve seat 13, and the first spool 15A and the second spool 15B are provided in the left-right direction (the direction perpendicular to the axis O) in each port (port pB, port, and port pF) of the first main valve seat 13, Ports pA, pF) are slightly movable relative to each other in a direction in which the ports (ports pC, pD, pE) provided in the second main valve seat 14 face each other, that is, in a direction orthogonal to the seating surfaces of the first main valve seat 13 and the second main valve seat 14, and are integrally movable in the vertical direction (the axis O direction).

In the illustrated example, an O-ring 18 is provided as an annular seal member between a step portion (inner peripheral step portion) formed on the inner periphery of the right end side of the first spool 15A and a step portion (outer peripheral step portion) formed on the outer periphery of the fitting convex portion 15B of the second spool 15B. Instead of the O-ring 18, a seal member such as a lip seal may be used.

Therefore, in a portion inside the O-ring 18, a high-pressure fluid (refrigerant) is introduced from a port (discharge-side high-pressure port) pA through the first U-shaped steering passage 16A, and the first U-shaped steering passage 16A and the main valve chamber 12 are sealed (closed) by the O-ring 18 disposed therebetween.

As can be seen from fig. 1, 2, and 3, the pressure receiving area Sb on the right side of the first spool 15A is larger than the pressure receiving area Sa on the left side (the first main valve seat 13 side) when viewed in the left-right direction (the direction perpendicular to the axis O).

More specifically, a projected area (pressure receiving area Sb) of an inner side of the O-ring 18 with respect to a plane perpendicular to the left-right direction and a surface of a left-direction pressure received by (a right surface of) the first spool 15A due to the high-pressure refrigerant introduced into the first U-shaped steering passage 16A is larger than a projected area (pressure receiving area Sa) of the annular seal surface on the first main valve seat 13 side with respect to a plane perpendicular to the left-right direction (that is, here, an area substantially equal to a projected area of the inner flange portion 15A) and a surface of a right-direction pressure received by (a left surface of) the first spool 15A due to the high-pressure refrigerant flowing through the port (inside of the annular seal surface).

Thus, when the high-pressure refrigerant is introduced into the first U-shaped turning passage 16A through the port (discharge side high-pressure port) pA, by the pressure received from the (high-pressure refrigerant in the) first U-turn passage 16A (more specifically, the differential pressure between the pressure received from the refrigerant (high-pressure refrigerant) flowing through the first U-turn passage 16A and the pressure received from the refrigerant (low-pressure refrigerant) flowing through the second U-turn passage 16B), the right surface (annular seal surface) of the second slide valve body 15B is pressed against the seat surface of the second main valve seat 14, the left surface (annular seal surface) of the first spool 15A is pressed against the seat surface of the first main valve seat 13 by a differential pressure acting on the first spool 15A due to a difference (Sb-Sa) in pressure receiving areas between the right surface and the left surface of the first spool 15A.

Further, between the first spool 15A and the second spool 15B, for example, an urging member (an annular plate spring, a compression coil spring, or the like) that urges the first spool 15A and the second spool 15B in opposite directions (separating directions) to each other may be disposed outside the O-ring 18 between the right surface of the first spool 15A and a stepped surface (a leftward stepped surface) on which the fitting convex portion 15B of the second spool 15B is formed, so that the left surface (the annular seal surface) of the first spool 15A is pressed (pressed) against the valve seat surface of the first main valve seat 13, and the right surface (the annular seal surface) of the second spool 15B is pressed (pressed) against the valve seat surface of the second main valve seat 14.

In this example, a reinforcing pin 15d for shape retention is provided so as to extend in the front-rear direction substantially in the center of the second U-shaped steering passage 16B of the second spool 15B (also see fig. 5).

In this example, a recessed surface 15e is formed on the upper and lower surfaces of the main valve element 15 (the first spool 15A and the second spool 15B constituting the main valve element 15), and a support plate portion 25c of (the

coupling plates

25A and 25B of) the coupling body 25 (described later) is fitted into the recessed surface 15e (with a slight gap in the left-right direction).

As described above, in the main spool 15, the first spool 15A and the second spool 15B move in the direction of the axis O integrally with each other, so that the cooling position (upper end position) shown in fig. 1 and the heating position (lower end position) shown in fig. 2 can be selectively obtained, the cooling position is with port pF open and port pB and port pA in communication via a first U-shaped steering passage 16A of the first spool 15A, and a position where the port pE is opened and the port pC and the port pD are communicated via the second U-turn passage 16B of the second spool 15B, the heating position is to open the port pB and to communicate the port pA with the port pF via the first U-shaped steering passage 16A of the first spool 15A, and a position at which the port pC is opened and the port pD and the port pE are communicated via the second U-turn passage 16B of the second spool 15B.

The first slide spool 15A of the main spool 15 is located just above two of the three ports (port pB and port pA, or port pA and port pF) other than when moving, and the second slide spool 15B of the main spool 15 is located just above two of the three ports (port pC and port pD, or port pD and port pE) other than when moving, and at this time, the first slide spool 15A and the second slide spool 15B are pressed leftward and rightward and pressed against the seat surfaces of the first main valve seat 13 and the second main valve seat 14, respectively, by the pressure of the high-pressure refrigerant introduced into (the first U-shaped steering passage 16A of) the main spool 15.

The first piston 21 and the second piston 22 are connected to each other by a connecting body 25 so as to be movable integrally, and the first spool 15A and the second spool 15B of the main valve 15 are fitted and supported by the connecting body 25 in a state in which they are slightly slidable in the left-right direction and the movement in the front-rear direction is substantially prevented.

In this example, the coupling body 25 is formed of a pair of plate members of the same size and the same shape, which are manufactured by press forming or the like, for example, and each of the plate members is arranged in the left-right direction (the direction orthogonal to the valve seat surfaces of the first main valve seat 13 and the second main valve seat 14) (in other words, parallel to the plane orthogonal to the valve seat surfaces), and the pair of plate members are arranged to face each other in the front-rear direction, and the main valve element 15 is sandwiched between the pair of plate members (in the front-rear direction). Hereinafter, the plate material disposed on the front side of main valve element 15 is referred to as a coupling plate 25A, and the plate material disposed on the rear side of main valve element 15 is referred to as a coupling plate 25B.

More specifically, as can be seen from fig. 1 and 2, and fig. 4 and 5, each of the connecting

plates

25A and 25B is formed of a plate material having a vertically long rectangular shape (here, the same width over the entire length in the vertical direction) and is symmetrical with respect to a center line (symmetry line) extending in the front-rear direction from the center of each of the connecting

plates

25A and 25B. A support plate portion 25c having a shape (i.e., a substantially concave cross section) along the outer periphery (front surface and top and bottom surfaces or rear surface and top and bottom surfaces) of the main valve element 15 is formed at substantially the center (in the vertical direction) of each of the

coupling plates

25A and 25B so as to engage and support (a front portion or a rear portion of) the main valve element 15 so as to be movable integrally in the axis O direction. The width (in the left-right direction) of the support plate portion 25c is slightly smaller than the width of the recessed surface 15e provided on the upper and lower surfaces of the valve body 15.

A connecting plate portion 25A extending up to the first piston 21 or the second piston 22 is connected to the upper and lower portions of the support plate portion 25c of each connecting

plate

25A, 25B. Here, the connecting plate portion 25a is formed into a step shape or a crank shape by bending or the like, and includes an offset plate portion 25aa and a butt plate portion 25ab from the support plate portion 25c side. The offset plate 25aa of the connecting plate 25A of the front connecting plate 25A is disposed in front of the axis O, and in particular, is disposed in a position avoiding the six ports pA to pF open to the seating surfaces of the first main valve seat 13 and the second main valve seat 14 on the front side when viewed in the left-right direction (in other words, a position offset to the front side from the six ports pA to pF), and the offset plate 25aa of the connecting plate 25A of the rear connecting plate 25B is disposed in the rear of the axis O, and in particular, is disposed in a position avoiding the six ports pA to pF open to the seating surfaces of the first main valve seat 13 and the second main valve seat 14 on the rear side when viewed in the left-right direction (in other words, a position offset to the rear side from the six ports pA to pF). That is, in this example, when viewed in the left-right direction, the offset plate portions 25aa of the connecting plate portions 25A of the pair of connecting

plates

25A, 25B are disposed apart from each other (in the front-rear direction) of the respective ports pA to pF that open in the seating surfaces of the first main valve seat 13 and the second main valve seat 14, and the respective ports pA to pF (more specifically, the port pF and the port pE that are located on the lower side in the cooling position (upper end position) shown in fig. 1 and the port pB and the port pC that are located on the upper side in the heating position (lower end position) shown in fig. 2) are located between the connecting plate portions 25A of the pair of connecting

plates

25A, 25B (see fig. 4 in particular).

Further, the abutment plate portion 25ab of the connecting plate portion 25A of the connecting

plates

25A, 25B (a portion which is close to the first piston 21 or the second piston 22 and which does not overlap with the ports pA to pF opened in the seating surfaces of the first main valve seat 13 and the second main valve seat 14) is abutted against the abutment plate portion 25ab of the connecting plate portion 25A of the opposite (opposing) connecting

plates

25B, 25A. In consideration of the ease of assembly and the like (described in detail later), the abutting plate portion 25ab may be provided with projections and depressions (positioning portions) for positioning the

coupling plates

25A and 25B arranged to face each other.

Further, mounting leg portions 25B are provided at upper and lower end portions of (the connecting plate portions 25A of) the

coupling plates

25A, 25B, the mounting leg portions 25B are formed by being bent at substantially 90 ° toward a side (a direction in which the support plate portions 25c having substantially concave cross sections are formed) opposite to the side of the

coupling plates

25B, 25A disposed to face each other, screw holes 29 are provided through the mounting leg portions 25B, and bolts 30 for coupling the

coupling plates

25A, 25B to the first piston 21 or the second piston 22 are inserted through the screw holes 29.

In this example, the length of the connecting plate portion 25A (offset plate portion 25aa + abutting plate portion 25ab) of each of the

coupling plates

25A and 25B in the vertical direction (the axis O direction) is shorter than the length of the first and

second piston portions

11a and 11B of the main valve housing 11. Thus, (the outer peripheral portion of the first piston portion 11a of) the upper connecting cover 11d of the main valve housing 11 is provided as a stopper that abuts (the upper end side corner portion of) the support plate portion 25c of (each of the connecting

plates

25A, 25B of) the connecting body 25 to prevent upward movement of (the main valve body 15 fitted to) the connecting body 25, and (the outer peripheral portion of the second piston portion 11B of) the lower connecting cover 11e of the main valve housing 11 is provided as a stopper that abuts (the lower end side corner portion of) the support plate portion 25c of (each of the connecting

plates

25A, 25B of) the connecting body 25 to prevent downward movement of (the main valve body 15 fitted to) the connecting body 25.

In other words, in this example, the stopper 25s that abuts the upper connection cover 11d or the lower connection cover 11e of the main valve housing 11 to regulate the movement of the main valve element 15 in the vertical direction is provided in (the support plate portion 25c of each of the

connection plates

25A and 25B of) the connection body 25.

As described above, by providing the stopper 25s for restricting the movement of the main valve element 15 in the coupling body 25, for example, as compared with a configuration in which the upper end-side cover member 11A and the lower end-side cover member 11B are both stoppers for preventing the upward movement of the first piston 21 and the downward movement of the second piston 22, it is possible to reduce the load applied to the first and

second pistons

21 and 22, and to reduce the dimensional accuracy of the components of the first and

second pistons

21 and 22, the upper end-side and lower end-

side cover members

11A and 11B, and the like, which are used for restricting the position of the main valve element 15. As described above, the upper end-side cover member 11A and the lower end-side cover member 11B may be stoppers that prevent both the upward movement of the first piston 21 and the downward movement of the second piston 22 (i.e., the upward and downward movement of the main spool 15).

In this example, since the

coupling plates

25A and 25B are formed of plate materials having the same size and the same shape as described above, the two

coupling plates

25A and 25B are arranged to face each other in the front-rear direction, and the abutting plate portions 25ab of the connecting plate portions 25A of the two

coupling plates

25A and 25B are arranged in a combined manner in the opposite directions (in detail, in the vertically opposite direction) by abutting each other, and the mounting leg portions 25B are fixed to the first piston 21 or the second piston 22 via the bolts 30. The first spool 15A and the second spool 15B of the main spool 15 are disposed (from the left-right direction, respectively) between the support plate portions 25c of the connecting

plates

25A, 25B (substantially rectangular spaces in side view), and the first spool 15A and the second spool 15B of the main spool 15 are fitted to the connecting body 25 in a state in which they are slightly slidable in the left-right direction and movement in the front-rear direction is substantially prevented (see fig. 5 in particular).

The main valve element 15 fitted and supported by (the pair of

coupling plates

25A, 25B of) the coupling body 25 is pushed by an upper portion or a lower portion (a rectangular plane having a wide width in the left-right direction) of a support plate portion 25c having a concave cross section of the

coupling plates

25A, 25B of the coupling body 25 (here, upper and lower surfaces of the first spool 15A and the second spool 15B of the main valve element 15 are pressed) in accordance with the reciprocating movement of the first and

second pistons

21, 22, and reciprocates between a cooling position (upper end position) and a heating position (lower end position).

In the present example, the connecting member 25 is illustrated as being formed of a pair of plate members (connecting

plates

25A and 25B) having the same size and the same shape, but it goes without saying that the connecting member 25 may be formed of, for example, one plate member.

[ operation of six-way valve body 10 ]

Next, the operation of the six-way valve body 10 having the above-described configuration will be described.

When the main valve 15 disposed in the main valve housing 11 is in the heating position (lower end position) (the second communication state shown in fig. 2), the second operating chamber 32 is communicated with the port pA, which is the discharge-side high-pressure port, and the first operating chamber 31 is communicated with the port pD, which is the suction-side low-pressure port, via the four-way pilot valve 90, which will be described later, high-temperature high-pressure refrigerant is introduced into the second operating chamber 32, and high-temperature high-pressure refrigerant is discharged from the first operating chamber 31. Therefore, the pressure of the second operating chamber 32 on the other end side (lower end side) of the main valve chamber 12 is higher than the pressure of the first operating chamber 31 on one end side (upper end side) of the main valve chamber 12, and as shown in fig. 1, the first and

second pistons

21 and 22 and the main valve body 15 move upward, the stopper 25 of (the support plate portion 25c of each of the connecting

plates

25A and 25B of) the connecting body 25 abuts and is locked to the upper connecting cap 11d, and the main valve body 15 is at the cooling position (upper end position) (the first communication state shown in fig. 1).

Thus, the port pA is made to communicate with the port pB (via the first U-turn passage 16A), the port pC is made to communicate with the port pD (via the second U-turn passage 16B), and the port pE is made to communicate with the port pF (via the main valve chamber 12), so that the cooling operation is performed in the heat pump type cooling and heating system.

When the main valve 15 is at the cooling position (upper end position) (the first communication state shown in fig. 1), the first operating chamber 31 is communicated with the port pA, which is the discharge-side high-pressure port, and the second operating chamber 32 is communicated with the port pD, which is the suction-side low-pressure port, via the four-way pilot valve 90, which will be described later, high-temperature and high-pressure refrigerant is introduced into the first operating chamber 31, and high-temperature and high-pressure refrigerant is discharged from the second operating chamber 32. Therefore, the pressure of the first operating chamber 31 on one end side (upper end side) of the main valve chamber 12 is higher than the pressure of the second operating chamber 32 on the other end side (lower end side) of the main valve chamber 12, and as shown in fig. 2, the first and

second pistons

21 and 22 and the main valve body 15 move downward, the stopper 25s of the support plate 25c of (the connecting

plates

25A and 25B of) the connecting body 25 abuts and is locked to the lower connecting cover 11e, and the main valve body 15 is at the heating position (lower end position) (second communication state shown in fig. 2).

Thus, the port pA and the port pF are communicated with each other (via the first U-turn passage 16A), the port pE and the port pD are communicated with each other (via the second U-turn passage 16B), and the port pC and the port pB are communicated with each other (via the main valve chamber 12), so that the heat pump type cooling and heating system performs a heating operation.

[ Structure of four-way Pilot valve 90 ]

The four-way pilot valve 90 as a pilot valve is known in its own structure, and as shown in enlarged views in fig. 6(a) and (B), a valve housing 92 made of a cylindrical straight tube having an electromagnetic coil 91 fitted and fixed to the outside thereof is provided on the outer periphery of the base end side (left end side), and in the valve housing 92, a suction element 95, a compression coil spring 96, and a plunger 97 are arranged in series in this order from the base end side.

The left end portion of the valve housing 92 is sealingly joined to a flange-like portion (outer peripheral stepped portion) of the suction element 95 by welding or the like, and the suction element 95 is fastened and fixed to a cover 91A covering the outer periphery of the electromagnetic coil 91 for energization and excitation by a bolt 92B.

On the other hand, a cap member 98 with a filter having a thin tube insertion port (high-pressure introduction port a) for introducing a high-pressure refrigerant is airtightly attached to the right end opening of the valve housing 92 by welding, brazing, caulking, or the like, and a region surrounded by the cap member 98, the plunger 97, and the valve housing 92 is a valve chamber 99. A high-temperature and high-pressure refrigerant is introduced into the valve chamber 99 from the port (discharge-side high-pressure port) pA via a flexible high-pressure narrow tube # a airtightly inserted into a narrow tube insertion port (high-pressure introduction port a) of the cap member 98.

Further, a valve seat 93 having a flat inner end surface is airtightly joined by brazing or the like between the plunger 97 and the cover member 98 in the valve housing 92, and in the valve seat surface (inner end surface) of the valve seat 93, a port b connected to the first operation chamber 31 of the six-way valve body 10 via a narrow tube # b, a port c connected to a port (suction-side low-pressure port) pD via a narrow tube # c, and a port d connected to the second operation chamber 32 via a narrow tube # d are opened in parallel laterally at predetermined intervals in the longitudinal direction (left-right direction) of the valve housing 92 in this order from the tip end side (right end side).

The plunger 97 disposed to face the suction element 95 is substantially cylindrical and is disposed slidably in the valve case 92 in the axial direction (in the direction along the center line L of the valve case 92). A valve element holder 94A is fixedly attached to an end portion of the plunger 97 on the side opposite to the suction element 95 by press fitting, caulking, or the like, with a base end portion thereof together with the attachment 94B, and the valve element holder 94A holds the valve element 94 slidably in the thickness direction on a free end side thereof. A plate spring 94C is attached to the valve element holder 94A, and the plate spring 94C biases the valve element 94 in a direction (thickness direction) in which the valve element is pressed against the valve seat 93. The valve body 94 slides on the seat surface of the valve seat 93 in accordance with the movement of the plunger 97 in the lateral direction in a state of abutting against the seat surface of the valve seat 93 in order to switch the communication state among the ports b, c, and d that are opened on the seat surface of the valve seat 93.

The valve body 94 is provided with a recessed portion 94a, and the size of the recessed portion 94a is such that the adjacent ports b-c and c-d of the three ports b-d that open on the seat surface of the valve seat 93 can be selectively communicated with each other.

The compression coil spring 96 is attached to be compressed between the suction element 95 and the plunger 97 and biases the plunger 97 in a direction (rightward in the drawing) of separating from the suction element 95, and (a left end portion of) the valve seat 93 is a stopper that stops rightward movement of the plunger 97 in this example. As the structure of the stopper, it is needless to say that other structures can be adopted.

The four-way pilot valve 90 is attached to an appropriate position such as the back surface side of the six-way valve body 10 via a mounting tool 92A. In the four-way pilot valve 90, the port pD, which is the suction-side low-pressure port, is connected to the narrow tube # c, but the port pC through which the medium-pressure refrigerant flows may be connected to the narrow tube # c.

[ operation of the four-way pilot valve 90 ]

In the four-way pilot valve 90 configured as described above, when the electromagnetic coil 91 is not energized, the plunger 97 is pushed by the biasing force of the compression coil spring 96 until the right end thereof comes into contact with the valve seat 93, as shown in fig. 1 and 6 (a). In this state, the spool 94 is positioned above the port b and the port c, the port b communicates with the port c through the recess 94a, and the port d communicates with the valve chamber 99, so that the high-pressure fluid flowing into the port (discharge side high-pressure port) pA is introduced into the second action chamber 32 via the high-pressure thin tube # a → the valve chamber 99 → the port d → the thin tube # d → the port p12, and the high-pressure fluid of the first action chamber 31 flows and is discharged to the port p11 → the thin tube # b → the port b → the recess 94a → the port c → the thin tube # c → the port (suction side low-pressure port) pD.

On the other hand, when the electromagnetic coil 91 is energized, the plunger 97 is attracted by the attraction force of the attraction element 95 until the left end thereof comes into contact with the attraction element 95 (against the biasing force of the compression coil spring 96), as shown in fig. 2 and 6 (B). At this time, the spool 94 is positioned on the port c and the port d, and the port c communicates with the port d and the port b communicates with the valve chamber 99 through the recessed portion 94a, so that the high-pressure fluid flowing into the port (discharge side high-pressure port) pA is introduced into the first operating chamber 31 via the high-pressure thin tube # a → the valve chamber 99 → the port b → the thin tube # b → the port p11, and the high-pressure fluid of the second operating chamber 32 flows into and is discharged from the port p12 → the thin tube # d → the port d → the recessed portion 94a → the port c → the thin tube # c → the port (suction side low-pressure port) pD.

Therefore, when the current to the solenoid 91 is turned off, the main valve element 15 of the six-way valve body 10 is shifted from the heating position (second communication state) to the cooling position (first communication state) to perform the flow path switching as described above, and when the current to the solenoid 91 is turned on, the main valve element 15 of the six-way valve body 10 is shifted from the cooling position (first communication state) to the heating position (second communication state) to perform the flow path switching as described above.

As described above, in the six-way switching valve 1 of the present embodiment, by switching the energization of the electromagnetic four-way pilot valve 90 on/off, the main valve element 15 constituting the six-way valve body 10 is moved in the main valve chamber 12 by the differential pressure between the high-pressure fluid (fluid flowing through the port pA which is a high-pressure portion) and the low-pressure fluid (fluid flowing through the port pD which is a low-pressure portion) flowing through the six-way switching valve 1, and the communication state between the total six ports provided in the main valve housing 11 can be switched, and in the heat pump type cooling and heating system, switching from the heating operation to the cooling operation and switching from the cooling operation to the heating operation are performed.

[ Effect of six-way selector valve 1 ]

As can be understood from the above description, in the six-way switching valve 1 of the present embodiment, in the main valve chamber 12, the port pB, the port pA, and the port pF are opened side by side in the axis O direction, and on the opposite side of the port pB, the port pA, and the port pF with respect to the axis O, the port pC, the port pD, and the port pE are opened side by side in the axis O direction, a first U-turn passage 16A and a second U-turn passage 16B are provided in the main valve spool 15, and the main valve spool 15 is moved in the main valve chamber 12, whereby a first communication state in which the port pA and the port pB communicate via the first U-turn passage 16A, the port pC and the port pD communicate via the main valve passage 16B, and a second communication state in which the port pE and the port communicate via the main valve chamber 12 can be selectively obtained, a state in which the port pE and the port pD are made to communicate via the second U-shaped turn passage 16B, and the port pC and the port pB are made to communicate via the main valve chamber 12. Therefore, compared to a six-way selector valve using a conventional sliding main spool, the main valve seats (first main valve seat 13 and second main valve seat 14) provided with ports and the main spool 15 can be shortened (in the axis O direction), and therefore, the surface accuracy (flatness) of the seat surfaces of the main valve seats (first main valve seat 13 and second main valve seat 14) and the seal surfaces of the main spool 15 can be easily ensured, valve leakage can be suppressed, and fluid (for example, high-pressure fluid (refrigerant)) flows through the first U-shaped steering passage 16A, and pressure loss can be reduced.

In addition, in the present embodiment, since the fluid (for example, low-pressure refrigerant) flowing in the six-way valve body 10 flows through the second U-turn passage 16B and the fluid (for example, intermediate-pressure refrigerant) flows in the left-right direction (linearly) in the main valve chamber 12, the pressure loss can be reduced.

In addition to the above, when the six-way switching valve 1 of the present embodiment is used in an environment where a high-temperature and high-pressure refrigerant and a low-temperature and low-pressure refrigerant flow, such as a heat pump type cooling and heating system, the first U-turn passage (high-pressure side U-turn passage) 16A through which the high-temperature and high-pressure refrigerant flows and the second U-turn passage (low-pressure side U-turn passage) 16B through which the low-temperature and low-pressure refrigerant flows are provided so as to be separated far apart from each other without passing through a metal main valve seat, for example, and therefore, compared to a conventional structure in which the high-temperature and high-pressure refrigerant and the low-temperature and low-pressure refrigerant flow in a close state through a metal main valve seat, the amount of heat exchange therebetween (i.e., heat loss) can be significantly reduced, and therefore, the effect of improving the efficiency of the system can also be obtained.

In the six-way switching valve 1 of the present invention, the main valve body 15 includes a first cylindrical spool (high-pressure side spool) 15A and a second spool (low-pressure side spool) 15B, the second spool 15B has a fitting projection 15B slidably fitted into the first spool 15A on a left side surface (a side surface on the first spool 15A side), and the fitting projection 15B is fitted into the first spool 15A, so that the first U-shaped turning passage (high-pressure side U-shaped turning passage) 16A is formed by partitioning between an inner peripheral surface of the first spool 15A and a left end surface of the fitting projection 15B, and the second spool 15B is pressed (pressure-contacted) against the second main valve seat 14 having the port by (fluid pressure of) high-pressure fluid introduced into the first U-shaped turning passage 16A. Therefore, valve leakage can be more effectively suppressed while suppressing the size of main poppet 15 (in particular, the size in the direction orthogonal to axis O).

Further, since the outer shape of the annular seal surface of the first spool 15A on the first main valve seat 13 side where the three ports (port pB, port pA, and port pF) are provided is smaller than the outer shape of the O-ring 18 disposed between the fitting convex portions 15B of the first spool 15A and the second spool 15B, the first spool 15A is pressed (pressure-contacted) against the first main valve seat 13 where the ports are provided by the differential pressure acting on the first spool 15A due to the difference in the pressure receiving area of the first spool 15A, and thus valve leakage can be suppressed more effectively.

[ other examples of the six-way selector valve 1 ]

In the above embodiment, the passage area (cross-sectional area substantially perpendicular to the flow direction) of the second U-turn passage (low-pressure side U-turn passage) 16B on the second spool 15B side is made substantially the same as the passage area (cross-sectional area substantially perpendicular to the flow direction) of the first U-turn passage (high-pressure side U-turn passage) 16A on the first spool 15A side, but the flow rate of the second U-turn passage (low-pressure side U-turn passage) 16B may be made larger than the flow rate of the first U-turn passage (high-pressure side U-turn passage) 16A (in other words, the high-pressure refrigerant flowing through the first U-turn passage 16A is compressed), and in response thereto, as shown in fig. 7, the fitting convex portion 15B of the second spool 15B (in the example of the figure) may be made larger, and the passage area of the second U-turn passage 16B may be made larger than the passage area of the first U-turn passage 16A, the high-low pressure flow path ratio is also changed. With this configuration, the high-low pressure flow path ratio of the low pressure side U-turn passage to the high pressure side U-turn passage can be set to the optimum ratio. Therefore, the flow path switching valve is particularly suitable for use in a cooling and heating system or the like in which the flow path area of the low-pressure side flow path is made larger than the flow path area of the high-pressure side flow path.

In the above embodiment, the first U-turn passage (high-pressure side U-turn passage) 16A on the first slide valve body 15A side has a substantially concave shape, but in order to smooth the flow of the high-pressure refrigerant in the first U-turn passage 16A and reduce noise, as shown in fig. 8, a guide surface 15c formed of a bowl-shaped recess having an arc-shaped corner may be formed on the left end surface of the fitting convex portion 15B of the second slide valve body 15B. In this case, as shown in the drawing, the left end surface of the fitting convex portion 15B of the second spool 15B may be disposed close to the inner flange-like portion 15A of the first spool 15A.

In the six-way switching valve 1 of the above embodiment, the configuration in which the main valve element 15 is driven in the main valve chamber 12 using the four-way pilot valve 90 has been described, but, for example, a configuration in which the main valve element 15 is driven in the main valve chamber 12 using a motor may be employed instead of the four-way pilot valve 90.

In addition, the six-way switching valve 1 according to the above embodiment can be incorporated not only in the heat pump type cooling and heating system, but also in other systems, devices, and facilities.

Claims

1. A six-way switching valve is provided with: a cylindrical main valve housing defining a main valve chamber; a port, wherein six ports are provided in total in the main valve housing; and a sliding main spool disposed in the main valve chamber so as to be movable in an axial direction,

Wherein a plurality of communication passages for selectively communicating between the ports are provided in the main spool, and the ports that can communicate with each other can be switched by moving the main spool, the six-way switching valve being characterized in that,

three ports open to the main valve chamber side by side in the axial direction, and on the opposite side of the three ports with respect to the axial line, the other three ports open to the main valve chamber side by side in the axial direction,

the main valve element has a low-pressure side slide valve element and a cylindrical high-pressure side slide valve element, the low-pressure side slide valve element has an engaging projection slidably fitted in the high-pressure side slide valve element on one side surface, the engaging projection is fitted in the high-pressure side slide valve element so that a high-pressure side U-shaped turning passage selectively communicating two of the three ports is formed by partitioning by an inner peripheral surface of the high-pressure side slide valve element and an end surface of the engaging projection, and relatively high-pressure fluid is introduced into the high-pressure side U-shaped turning passage, the high-pressure side slide valve element and the low-pressure side slide valve element are integrally movable in an axial direction and slidably movable with each other in a direction perpendicular to the axial line, and a low-pressure side U-shaped turning passage selectively communicating two of the other three ports is opened on the other side surface of the low-pressure side slide valve element, and the low-pressure side U-turn passage is introduced with relatively low-pressure fluid,

Moving said main poppet within said main valving chamber,

thereby, a plurality of communication states can be selectively obtained as follows: communicating two of the three ports via the high pressure side U-turn passage, two of the other three ports via the low pressure side U-turn passage, and one of the other three ports through the main valve housing.

2. The six-way switching valve according to claim 1,

an annular seal member is disposed between the high-pressure side spool and the fitting projection of the low-pressure side spool.

3. The six-way switching valve according to claim 2,

the shape of the annular sealing surface of the high-pressure side sliding valve element on the main valve seat side provided with the three ports is smaller than that of the sealing component.

4. The six-way switching valve according to claim 3,

an inner flange-shaped portion is provided on an inner periphery of an end portion of the high-pressure side sliding spool on the main valve seat side where the three ports are provided, and the annular seal surface is formed on an end surface of the inner flange-shaped portion on the main valve seat side.

5. The six-way switching valve according to any one of claims 2 to 4,

a force application member that applies force in opposite directions to the high-pressure side spool and the low-pressure side spool is disposed between the high-pressure side spool and the low-pressure side spool.

6. The six-way switching valve of claim 5,

the biasing member is disposed outside the sealing member.

7. The six-way switching valve according to any one of claims 1 to 4,

the passage area of the low-pressure side U-shaped steering passage is larger than the passage area of the high-pressure side U-shaped steering passage.

8. The six-way switching valve according to any one of claims 1 to 4,

a guide surface formed of a bowl-shaped recess is formed on an end surface of the fitting convex portion, and the guide surface smoothes the flow of the high-pressure fluid in the high-pressure-side U-turn passage.

9. The six-way switching valve according to any one of claims 1 to 4,

a first variable displacement operating chamber is provided on one end side of the main valve chamber in the main valve housing, a second variable displacement operating chamber is provided on the other end side of the main valve chamber, the first variable displacement operating chamber is defined by a first piston, the second variable displacement operating chamber is defined by a second piston, and the first and second operating chambers are selectively introduced and discharged with high-pressure fluid, the main valve body is arranged so as to be movable in the axial direction in conjunction with the first and second pistons, and the main valve body moves the first and second pistons by controlling the introduction and discharge of the high-pressure fluid into and from the first and second operating chambers.

10. The six-way switching valve according to claim 9,

the first piston and the second piston are connected to each other so as to be integrally movable by a connecting body made of one or more plate materials arranged in a direction orthogonal to a valve seat surface of a main valve seat provided with the port, and the main valve body is supported by the connecting body so as to be slidable in the direction orthogonal to the valve seat surface of the main valve seat and moves in accordance with the reciprocal movement of the first piston and the second piston.

11. The six-way switching valve according to claim 10,

the coupling body is provided with a stopper portion for restricting the movement of the main valve element in the axial direction.

12. The six-way switching valve according to claim 11,

the stopper abuts against the main valve housing.