JP2021099115A - Pilot valve - Google Patents

Abstract

To provide a pilot valve capable of controlling a four-way switching valve which enables a number of flow path switching patterns while suppressing increase in the number of components.SOLUTION: A pilot valve 1 includes a first control pipe a, second control pipes b, e, a third control pipe d, a fourth control pipe f, and a fifth control pipe g, into which high pressure refrigerant is introduced. When the high pressure refrigerant is introduced into the second control pipes b, e and the fifth control pipe g, the third control pipe d and the fourth control pipe f are connected to the second control pipes b, e, respectively. When low pressure refrigerant is introduced into the second control pipes b, e and the fifth control pipe g, the third control pipe d and the fourth control pipe f are connected to the second control pipes b, e, respectively. When the low pressure refrigerant is introduced into the second control pipes b, e and the high pressure refrigerant is introduced into the fifth control pipe g, the third control pipe d is connected to the first control pipe a and the fourth control pipe f is connected to the second control pipe e, or the third control pipe d is connected to the second control pipe e and the fourth control pipe f is connected to the first control pipe a, according to a control signal.SELECTED DRAWING: Figure 1

Description

The present invention relates to a pilot valve used for controlling a four-way switching valve.

The air conditioning system has a four-way switching valve that switches the flow direction of the refrigerant. An example of such a four-way switching valve is disclosed in Patent Document 1. The four-way switching valve of Patent Document 1 has a cylindrical valve body. Two pistons are arranged inside the valve body. The two pistons divide the inner space of the valve body into a main valve chamber, a first operating chamber and a second operating chamber. The two pistons are connected to a valve body arranged in the main valve chamber.

A high pressure port is provided in the main valve chamber of the valve body. The high pressure port is connected to the outlet of the compressor provided in the heating and cooling system. A valve seat is arranged in the main valve chamber. The valve seat surface of the valve seat is provided with a low pressure port connected to the suction port of the compressor and a first switching port and a second switching port connected to the heat exchanger of the air conditioning system.

In this four-way switching valve, one of the first operating chamber and the second operating chamber is connected to the high pressure port and the other is connected to the low pressure port by a pilot valve. As a result, the two pistons are moved to either of the operating chambers by the differential pressure between the first operating chamber and the second operating chamber, and the valve body is slid on the valve seat surface as the two pistons move. The valve body selectively connects the low pressure port to any of the first switching port and the second switching port by sliding on the valve seat surface.

Japanese Unexamined Patent Publication No. 2013-227989 International Publication No. 2017/09414

Recent air-conditioning systems include, for example, a configuration having two outdoor heat exchangers as shown in Patent Document 2. Such an air-conditioning system uses two outdoor heat exchangers as if they were one outdoor heat exchanger during the cooling operation and the heating operation. Then, when frost is formed on the outdoor heat exchanger during the heating operation, a high-temperature and high-pressure refrigerant is flowed through the other outdoor heat exchanger while using one outdoor heat exchanger to remove the heating operation without stopping the heating operation. Frost. Therefore, the air-conditioning system has a four-way switching valve for defrosting operation in addition to the four-way switching valve for switching the flow direction of the refrigerant described above. An example of a four-way switching valve for defrosting operation is shown in FIGS. 12 to 15.

The four-way switching valve 210 shown in FIGS. 12 to 15 has a main valve housing 211 which is a cylindrical valve body. The first piston 221 and the second piston 222 are arranged in the main valve housing 211. The first piston 221 and the second piston 222 divide the inner space of the main valve housing 211 into a first operating chamber 231, a main valve chamber 212, and a second operating chamber 232 in order from the left side of FIGS. 12 to 15. There is. An inner cylinder member 214 is arranged in the main valve chamber 212.

A first stem 261 is connected to the first piston 221. A first valve body 251 is provided at the tip end portion (right end portion) of the first stem 261. The first valve body 251 has a left valve body portion 251A and a right valve body portion 251B. The first piston 221 is pushed toward the first operating chamber 231 by the pressing spring 265.

A second stem 262 is connected to the second piston 222. A second valve body 252 is arranged at the tip end portion (left end portion) of the second stem 262. The second valve body 252 has a left valve body portion 252A and a right valve body portion 252B. The second piston 222 is pushed toward the second operating chamber 232 by the pressing spring 266.

A left cylindrical valve seat portion 245 is fitted in the left end portion of the inner cylinder member 214. The first stem 261 is inserted through the left cylindrical valve seat portion 245. At the tip (right end) of the left cylindrical valve seat portion 245, a first high pressure side valve seat 241A to which the left valve body portion 251A of the first valve body 251 is brought into contact with and separated from is provided.

A right cylindrical valve seat portion 246 is fitted in the right end portion of the inner cylinder member 214. A second stem 262 is inserted through the right cylindrical valve seat portion 246. A second high-pressure side valve seat 242B is provided at the tip end portion (left end portion) of the right side cylindrical valve seat portion 246 to contact and separate the right valve body portion 252B of the second valve body 252.

The inner cylinder member 214 has a first switching port side valve seat 241B which is arranged so as to face the first high pressure side valve seat 241A at a distance in the left-right direction and the right valve body portion 251B of the first valve body 251 is brought into contact with and separated from the inner cylinder member 214. It is provided. Further, the inner cylinder member 214 is arranged to face the second high-pressure side valve seat 242B at a distance in the left-right direction, and the left valve body portion 252A of the second valve body 252 is brought into contact with and separated from the second switching port side valve seat. 242A is provided.

The four-way switching valve 210 is provided at the discharge side high-pressure port pA connected to the discharge port of the compressor, the first inlet / output port pB1 connected to one of the two outdoor heat exchangers, and the other of the two outdoor heat exchangers. It has a second inlet / outlet port pB2 to be connected, and a switching inlet / outlet port pC connected to the discharge port of the compressor during the cooling operation and connected to the suction port of the compressor during the heating operation.

The discharge side high pressure port pA is connected to the main valve chamber 212. The first inlet / outlet port pB1 is connected to the space between the first high-pressure side valve seat 241A and the first switching port side valve seat 241B in the inner cylinder member 214. The second inlet / outlet port pB2 is connected to the space between the second high-pressure side valve seat 242B and the second switching port side valve seat 242A in the inner cylinder member 214. The switching input / output port pC is connected to the space between the first switching port side valve seat 241B and the second switching port side valve seat 242A in the inner cylinder member 214.

The four-way switching valve 210 has a first flow state and a second flow state during heating operation as a flow path switching pattern according to the relationship between the refrigerant pressures of the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232. It is configured to take either a third distribution state and a fourth distribution state during cooling operation. In the first distribution state, the second distribution state, and the third distribution state, the low-pressure refrigerant is introduced into the switching input / output port pC. In the fourth distribution state, the high-pressure refrigerant is introduced into the switching input / output port pC. The relationship of the refrigerant pressure is as follows: high pressure refrigerant> medium pressure refrigerant> low pressure refrigerant.

The four-way switching valve 210 is in the first distribution state when the low-pressure refrigerant is introduced into the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232. In the first flow state, as shown in FIG. 12, the left valve body portion 251A of the first valve body 251 is in contact with the first high pressure side valve seat 241A, and the right valve body portion 252B of the second valve body 252 is the second high pressure. The first inlet / outlet port pB1, the switching inlet / outlet port pC, and the second inlet / outlet port pB2 are communicated with each other in contact with the side valve seat 242B. The first distribution state is a state in which two outdoor heat exchangers are used as one outdoor heat exchanger during the heating operation.

When the high-pressure refrigerant is introduced into the main valve chamber 212, the high-pressure refrigerant is introduced into the first operating chamber 231 and the low-pressure refrigerant is introduced into the second operating chamber 232, the four-way switching valve 210 is in the second distribution state. In the second circulation state, as shown in FIG. 13, the right valve body portion 251B of the first valve body 251 is in contact with the first switching port side valve seat 241B, and the right valve body portion 252B of the second valve body 252 is the second. The discharge side high pressure port pA and the first inlet / outlet port pB1 are communicated with each other in contact with the high pressure side valve seat 242B, and the second inlet / outlet port pB2 and the switching inlet / outlet port pC are communicated with each other. The second distribution state is a state in which one of the two outdoor heat exchangers is defrosted during the heating operation and the other is used for the heating operation. In the second distribution state, the refrigerant pressure in the main valve chamber 212 becomes high pressure (high pressure refrigerant) only in the transition period from the first distribution state, and then the refrigerant flows from the main valve chamber 212 to the first inlet / output port pB1. , The refrigerant pressure in the main valve chamber 212 decreases to medium pressure (medium pressure refrigerant).

When the high-pressure refrigerant is introduced into the main valve chamber 212, the low-pressure refrigerant is introduced into the first operating chamber 231 and the high-pressure refrigerant is introduced into the second operating chamber 232, the four-way switching valve 210 is in the third distribution state. In the third flow state, as shown in FIG. 14, the left valve body portion 251A of the first valve body 251 is in contact with the first high pressure side valve seat 241A, and the left valve body portion 252A of the second valve body 252 is switched to the second. The first inlet / outlet port pB1 and the switching inlet / outlet port pC are communicated with each other in contact with the port side valve seat 242A, and the discharge side high pressure port pA and the second inlet / outlet port pB2 are communicated with each other. The third distribution state is a state in which one of the two outdoor heat exchangers is defrosted during the heating operation and one is used for the heating operation. In the third distribution state, the refrigerant pressure in the main valve chamber 212 becomes high pressure (high pressure refrigerant) only in the transition period from the first distribution state, and then the refrigerant flows from the main valve chamber 212 to the second inlet / outlet port pB2. , The refrigerant pressure in the main valve chamber 212 decreases to medium pressure (medium pressure refrigerant).

The four-way switching valve 210 is in the fourth distribution state when the high-pressure refrigerant is introduced into the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232. In the fourth flow state, as shown in FIG. 15, the left valve body portion 251A of the first valve body 251 is in contact with the first high pressure side valve seat 241A, and the right valve body portion 252B of the second valve body 252 is the second high pressure. The first inlet / outlet port pB1, the switching inlet / outlet port pC, and the second inlet / outlet port pB2 are in contact with each other in contact with the side valve seat 242B. The fourth distribution state is a state in which two outdoor heat exchangers are used as one outdoor heat exchanger during the cooling operation.

In this way, the four-way switching valve 210 can realize a large number of flow path switching patterns.

However, in order to realize a large number of flow path switching patterns, it is necessary to switch the refrigerant pressures of the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232 in the four-way switching valve 210. Therefore, a plurality of pilot valves are required to control the four-way switching valve 210, and there is a problem that the number of parts of the air conditioning system increases and the configuration becomes complicated.

Therefore, an object of the present invention is to provide a pilot valve capable of controlling a four-way switching valve capable of a large number of flow path switching patterns while suppressing an increase in the number of parts.

In order to achieve the above object, the pilot valve according to one aspect of the present invention is
A pilot valve used to control a four-way switching valve that switches the flow state of the refrigerant in the first outdoor heat exchanger and the second outdoor heat exchanger of the air conditioning system.
The four-way switching valve has a main valve chamber connected to the discharge port of the compressor of the air conditioning system via an on-off valve, and a first operating chamber and a second operating chamber partitioned from the main valve chamber. , The flow state is switched according to the refrigerant pressures of the main valve chamber, the first operating chamber and the second operating chamber.
The pilot valve
The first control pipe (a) connected to the discharge port of the compressor and
The second control pipes (b, e) connected to the discharge port of the compressor during the cooling operation and connected to the suction port of the compressor during the heating operation.
The third control pipe (d) connected to the first operating chamber and
The fourth control pipe (f) connected to the second operating chamber and
It has a fifth control pipe (g) connected to the discharge port of the compressor via the on-off valve.
When the on-off valve is in the open state during the cooling operation, the third control pipe (d) and the fourth control pipe (f) are connected to the second control pipe (b, e).
When the on-off valve is closed during the heating operation, the third control pipe (d) and the fourth control pipe (f) are connected to the second control pipe (b, e).
When the on-off valve is in the open state during the heating operation, the third control pipe (d) and the first control pipe (a) are connected and the fourth control pipe (f) is connected in response to the control signal. The second control tube (e) is connected, or the third control tube (d) and the second control tube (e) are connected, and the fourth control tube (f) and the first control are connected. It is characterized in that it is configured to connect to the pipe (a).

In the present invention
A tubular valve body in which the first pilot chamber, the second pilot chamber, the third pilot chamber, and the fourth pilot chamber are arranged in order in the axial direction, and
A first partition member arranged inside the valve body so as to partition the first pilot chamber and the second pilot chamber, and
A first valve body movably arranged inside the valve body so as to partition the second pilot chamber and the third pilot chamber, and a first valve body.
A second partition member arranged inside the valve body so as to partition the third pilot chamber and the fourth pilot chamber, and
A second valve body movably arranged in the fourth pilot chamber in the axial direction,
A first connection flow path that penetrates the second partition member in the axial direction and connects the third pilot chamber and the fourth pilot chamber.
A second connection flow path connecting the first connection flow path and the first pilot chamber,
A first valve seat that surrounds the opening on the third pilot chamber side in the first connection flow path and is provided so that the opening is opened and closed when the first valve body is brought into contact with each other.
A second valve seat that surrounds the opening on the side of the fourth pilot chamber in the first connection flow path and is provided so that the opening is opened and closed when the second valve body is brought into contact with each other.
The connection switching valve body arranged in the first pilot chamber and
It has a drive unit that drives the connection switching valve body, and has
The fifth control pipe (g) is connected to the second pilot chamber.
The second control pipe (b) is connected to the third pilot chamber.
The first control tube (a) is connected to the fourth pilot chamber.
The first valve body and the second valve body are connected by an operating rod inserted into the first connection flow path.
When the on-off valve is in the open state during the cooling operation, the first valve body is separated from the first valve seat and the second valve body is in contact with the second valve seat.
When the on-off valve is closed during the heating operation, the first valve body is separated from the first valve seat and the second valve body is in contact with the second valve seat.
When the on-off valve is in the open state during the heating operation, the first valve body is in contact with the first valve seat, the second valve body is separated from the second valve seat, and the drive unit receives the control signal. Correspondingly, the third control pipe (d) and the first pilot chamber are connected, and the fourth control pipe (f) and the second control pipe (e) are connected, or the third control is performed. It is preferable to drive the connection switching valve body so as to connect the pipe (d) and the second control pipe (e) and connect the fourth control pipe (f) and the first pilot chamber. ..

In the present invention
The first valve body is provided with a pressure equalizing hole for connecting the second pilot chamber and the third pilot chamber.
It is preferable that the pressure equalizing hole is configured so that the first valve body is closed before coming into contact with the first valve seat.

In order to achieve the above object, the pilot valve according to another aspect of the present invention is
The first control pipe (a) into which the high-pressure refrigerant is introduced and
The second control tube (b, e) and
The third control tube (d) and
The fourth control tube (f) and
It has a fifth control tube (g) and
When the high-pressure refrigerant is introduced into the second control pipe (b, e) and the fifth control pipe (g), the third control pipe (d), the fourth control pipe (f), and the second control Connect with the pipes (b, e),
When the low-pressure refrigerant is introduced into the second control pipe (b, e) and the fifth control pipe (g), the third control pipe (d), the fourth control pipe (f), and the second control Connect with the pipes (b, e),
When the low-pressure refrigerant is introduced into the second control pipes (b, e) and the high-pressure refrigerant or medium-pressure refrigerant is introduced into the fifth control pipe (g), the third control is performed according to the control signal. The pipe (d) and the first control pipe (a) are connected and the fourth control pipe (f) and the second control pipe (e) are connected, or the third control pipe (d) is connected. It is characterized in that it is configured to connect the second control tube (e) and the fourth control tube (f) and the first control tube (a).

According to the present invention, it is possible to control a four-way switching valve capable of a large number of flow path switching patterns while suppressing an increase in the number of parts.

It is sectional drawing of the pilot valve which concerns on one Example of this invention. It is an enlarged cross-sectional view of the pilot valve of FIG. 1 (during heating operation: first distribution state). FIG. 5 is an enlarged cross-sectional view of the pilot valve of FIG. 1 (state in which defrosting operation is started during heating operation: transition period from the first distribution state to the second distribution state and the third distribution state). FIG. 5 is an enlarged cross-sectional view of the pilot valve of FIG. 1 (state in which the first outdoor heat exchanger is defrosted during heating operation: second distribution state). FIG. 5 is an enlarged cross-sectional view of the pilot valve of FIG. 1 (state in which the second outdoor heat exchanger is defrosted during heating operation: third distribution state). FIG. 5 is an enlarged cross-sectional view of the pilot valve of FIG. 1 (during cooling operation: fourth distribution state). It is a table which shows the relationship between the operating state of an air-conditioning system and the state of a pilot valve. It is a schematic block diagram of an air-conditioning system (during heating operation). It is a schematic block diagram of an air-conditioning system (when the first outdoor heat exchanger is defrosted at the time of heating operation). It is a schematic block diagram of an air-conditioning system (when the second outdoor heat exchanger is defrosted at the time of heating operation). It is a schematic block diagram of an air-conditioning system (during cooling operation). It is sectional drawing of the four-way switching valve for defrosting operation (first flow state). It is sectional drawing of the four-way switching valve for defrosting operation (second flow state). It is sectional drawing of the four-way switching valve for defrosting operation (third distribution state). It is sectional drawing of the four-way switching valve for defrosting operation (fourth distribution state).

Hereinafter, a pilot valve according to an embodiment of the present invention will be described. The pilot valve of this embodiment is used to control the above-mentioned four-way switching valve 210 that realizes a defrosting operation in parallel with a heating operation in an air-conditioning system having two outdoor heat exchangers.

First, the air conditioning system 300 in which the pilot valve of this embodiment is used will be described.

As shown in FIGS. 8 to 11, the air conditioning system 300 includes a compressor 310, an indoor heat exchanger 320, a first outdoor heat exchanger 331, a second outdoor heat exchanger 332, an expansion valve 340, and the like. It has a four-way switching valve 350 for switching the flow direction of the refrigerant, an on-off valve 360, and a four-way switching valve 210 for the above-mentioned defrosting operation.

As shown in FIG. 8, during normal heating operation (operating state: heating), the on-off valve 360 is in the closed state, the four-way switching valve 350 for switching the flow direction is in the heating direction, and the four sides for defrosting operation. The switching valve 210 is set to the first distribution state. The refrigerant discharged from the discharge port 310a of the compressor 310 is the four-way switching valve 350, the indoor heat exchanger 320, the expansion valve 340, the first outdoor heat exchanger 331 and the second outdoor heat exchanger 332, and the four-way switching valve 210 in this order. (PB1, pB2 → pC), it passes through the four-way switching valve 350 and returns to the suction port 310b of the compressor 310.

As shown in FIG. 9, when the first outdoor heat exchanger 331 is defrosted during the heating operation (operating state: heating + defrosting 1), the on-off valve 360 is opened and the four sides for switching the flow direction are used. The switching valve 350 is in the heating direction, and the four-way switching valve 210 for defrosting operation is in the second distribution state. The refrigerant discharged from the discharge port 310a of the compressor 310 is, in order, a four-way switching valve 350, an indoor heat exchanger 320, an expansion valve 340, a second outdoor heat exchanger 332, a four-way switching valve 210 (pB2 → pC), and a four-way switching. It passes through the valve 350 and returns to the suction port 310b of the compressor 310. In parallel with this, the refrigerant discharged from the discharge port 310a of the compressor 310 passes through the on-off valve 360, the four-way switching valve 210 (pA → pB1), and the first outdoor heat exchanger 331 in this order, and exchanges the second outdoor heat. It joins the flow toward the vessel 332.

As shown in FIG. 10, when the second outdoor heat exchanger 332 is defrosted during the heating operation (operating state: heating + defrosting 2), the on-off valve 360 is opened and the four sides for switching the flow direction are used. The switching valve 350 is in the heating direction, and the four-way switching valve 210 for defrosting operation is in the third distribution state. The refrigerant discharged from the discharge port 310a of the compressor 310 is, in order, a four-way switching valve 350, an indoor heat exchanger 320, an expansion valve 340, a first outdoor heat exchanger 331, a four-way switching valve 210 (pB1 → pC), and a four-way switching. It passes through the valve 350 and returns to the suction port 310b of the compressor 310. In parallel with this, the refrigerant discharged from the discharge port 310a of the compressor 310 passes through the on-off valve 360, the four-way switching valve 210 (pA → pB2), and the second outdoor heat exchanger 332 in this order, and exchanges the first outdoor heat. It joins the flow toward the vessel 331.

As shown in FIG. 11, during the cooling operation (operating state: cooling), the on-off valve 360 is opened, the four-way switching valve 350 for switching the flow direction is in the cooling direction, and the four-way switching valve for defrosting operation is set. 210 is set as the fourth distribution state. The refrigerant discharged from the discharge port 310a of the compressor 310 is the four-way switching valve 350, the four-way switching valve 210 (pC → pB1, pB2), the first outdoor heat exchanger 331 and the second outdoor heat exchanger 332, and the expansion valve in this order. It passes through 340, the indoor heat exchanger 320, and the four-way switching valve 350, and returns to the suction port 310b of the compressor 310.

Next, the pilot valve 1 of this embodiment will be described. The pilot valve 1 controls the four-way switching valve 210 for defrosting operation in the air conditioning system 300 to switch the distribution state (first distribution state, second distribution state, third distribution state, and fourth distribution state). Used for.

The pilot valve 1 includes a valve body 10, a first partition member 20, a first valve body 30, a second partition member 40, a second valve body 50, a connection switching valve seat 60, and a connection switching valve body 70. And a drive unit 80. Further, the pilot valve 1 has a first control tube a, a second control tube b and e, a third control tube d, a fourth control tube f, and a fifth control tube g.

The valve body 10 is formed in a cylindrical shape. One end 10a (right end in FIG. 1) of the valve body 10 is closed with a cap 15. A drive unit 80 is arranged at the other end 10b (left end in FIG. 1) of the valve body 10 so as to close the other end 10b. The valve body 10 is provided with the first pilot chamber 11, the second pilot chamber 12, the third pilot chamber 13, and the fourth pilot chamber 14 side by side in this order from the other end 10b side toward the one end 10a side. .. The axis of the valve body 10 coincides with the axis L.

The first partition member 20 is formed in a columnar shape having the same outer diameter as the inner diameter of the valve body 10. The first partition member 20 is fixedly arranged inside the valve body 10 so as to partition the first pilot chamber 11 and the second pilot chamber 12.

The first valve body 30 is formed in a columnar shape having the same outer diameter as the inner diameter of the valve body 10. The first valve body 30 is arranged inside the valve body 10 so as to partition the second pilot chamber 12 and the third pilot chamber 13 so as to be movable in the axis L direction. A first valve closing spring 35 made of a compression coil spring is arranged between the first valve body 30 and the first partition member 20. The first valve closing spring 35 pushes the first valve body 30 toward one end 10a. An annular groove provided on the peripheral surface of the first valve body 30 is provided with a sealing member 36 made of an O-ring or the like that seals between the valve body 10 and the valve body 10.

The second partition member 40 has a partition main body portion 41 and a movable portion 42. The partition main body 41 is formed in a columnar shape having the same outer diameter as the inner diameter of the valve main body 10. The partition main body 41 is fixedly arranged inside the valve main body 10. The partition main body 41 is provided with a first connection flow path 43 that penetrates in the L direction of the axis and connects the third pilot chamber 13 and the fourth pilot chamber 14. The first connection flow path 43 has a diameter smaller than the inner diameter of the valve body 10 (that is, the second pilot chamber 12 and the third pilot chamber 13). The movable portion 42 is formed in an annular shape. The movable portion 42 is arranged so as to be movable in the axis L direction at the end portion of the partition main body portion 41 on the other end portion 10b side. A pressing spring 45 made of a compression coil spring is provided between the partition main body 41 and the movable portion 42. The pressing spring 45 pushes the movable portion 42 toward the other end portion 10b. The second partition member 40 is arranged so as to partition the third pilot chamber 13 and the fourth pilot chamber 14.

The first pilot chamber 11 is connected to the first connection flow path 43 by the second connection flow path 44.

The second pilot chamber 12 is connected to the fifth control pipe g, and is connected to the discharge side high pressure port pA of the four-way switching valve 210 by the fifth control pipe g. The fifth control pipe g is connected to the discharge port 310a of the compressor 310 via the discharge side high pressure port pA and the on-off valve 360. The state of being connected to the discharge port of the compressor includes a state in which the high pressure port pA on the discharge side is connected to the flow path on the discharge port side of the compressor rather than the other ports of the four-way switching valve 210.

The third pilot chamber 13 is connected to the second control pipe b, and is connected to the switching input / output port pC of the four-way switching valve 210 by the second control pipe b.

The fourth pilot chamber 14 is connected to the first control pipe a, and is connected to the vicinity of the discharge port 310 a of the compressor 310 by the first control pipe a. A high-pressure refrigerant is always introduced into the fourth pilot chamber 14 during the operation of the compressor 310. The first control tube a is connected to a position closer to the discharge port 310a of the compressor 310 than the discharge side high pressure port pA.

The second valve body 50 is formed in a columnar shape having the same outer diameter as the inner diameter of the valve body 10. The second valve body 50 is arranged in the fourth pilot chamber 14 so as to be movable in the axis L direction. The second valve body 50 is configured so that the refrigerant can flow between the space portion 14a on the one end portion 10a side and the space portion 14b on the other end portion 10b side in the fourth pilot chamber 14. A second valve closing spring 55 made of a compression coil spring is arranged between the second valve body 50 and the cap 15. The second valve closing spring 55 pushes the second valve body 50 toward the other end 10b.

The partition main body 41 of the second partition member 40 is provided with a first valve seat 47 and a second valve seat 48. The first valve seat 47 surrounds the opening on the third pilot chamber 13 side in the first connection flow path 43, and is provided so that the opening is opened and closed when the first valve body 30 is brought into contact with and separated from each other. The second valve seat 48 surrounds the opening on the side of the fourth pilot chamber 14 in the first connection flow path 43, and is provided so that the opening is opened and closed when the second valve body 50 is brought into contact with and separated from each other.

The first valve body 30 and the second valve body 50 are connected by an operating rod 38 inserted into the first connecting flow path 43. Therefore, when the second valve body 50 comes into contact with the second valve seat 48, the first valve body 30 separates from the first valve seat 47 and the third pilot passes through the first connection flow path 43 and the second connection flow path 44. The chamber 13 and the first pilot chamber 11 are connected. Alternatively, when the first valve body 30 comes into contact with the first valve seat 47, the second valve body 50 separates from the second valve seat 48 and is separated from the second valve seat 48 by the fourth pilot via the first connection flow path 43 and the second connection flow path 44. The chamber 14 and the first pilot chamber 11 are connected.

The pilot valve 1 is (1) when there is no differential pressure between the refrigerant pressure of the second pilot chamber 12 and the refrigerant pressure of the third pilot chamber 13 (specifically, when the differential pressure is less than a predetermined value), the second pilot valve 1 is used. (2) The refrigerant pressure in the second pilot chamber 12 is higher than the refrigerant pressure in the third pilot chamber 13 so that the valve body 50 is in contact with the second valve seat 48 and the first valve body 30 is separated from the first valve seat 47. When (specifically, when the differential pressure is equal to or higher than a predetermined value), the first opening is such that the first valve body 30 comes into contact with the first valve seat 47 and the second valve body 50 separates from the second valve seat 48. The valve spring 35 (force that pushes the first valve body 30), the second valve opening spring 55 (force that pushes the second valve body 50), and the inner diameter of the valve body 10 and the diameter of the first connection flow path 43 (the refrigerant is The force for pushing the first valve body 30 and the second valve body 50) is set.

The first valve body 30 is provided with a pressure equalizing hole 31 that connects the second pilot chamber 12 and the third pilot chamber 13. The pressure equalizing hole 31 is the refrigerant in the second pilot chamber 12 when the introduction of the high-pressure refrigerant or the medium-pressure refrigerant into the second pilot chamber 12 is stopped due to the valve opening / closing valve 360 changing from the valve open state to the valve closed state. Is released to the third pilot chamber 13 to quickly reduce the refrigerant pressure in the second pilot chamber 12. Further, when the first valve body 30 moves to the one end portion 10a side according to the refrigerant pressure of the second pilot chamber 12 and the refrigerant pressure of the third pilot chamber 13, the opening of the pressure equalizing hole 31 on the third pilot chamber 13 side. When the 31a is closed by the movable portion 42 and the first valve body 30 moves toward the other end portion 10b, the opening 31a is opened. In this embodiment, the opening 31a of the pressure equalizing hole 31 is configured to be closed by the movable portion 42 before the first valve body 30 comes into contact with the first valve seat 47. By closing the opening 31a of the pressure equalizing hole 31, it is regulated that the refrigerant flows from the second pilot chamber 12 to the third pilot chamber 13 more than necessary through the pressure equalizing hole 31.

The connection switching valve seat 60 is fixedly arranged in the first pilot chamber 11 of the valve body 10. As shown in FIG. 2, the connection switching valve seat 60 has a valve seat surface 64 through which the first port 61, the second port 62, and the third port 63 are opened.

The first port 61 is connected to the second control pipe e, and is connected to the switching input / output port pC of the four-way switching valve 210 by the second control pipe e.

The second port 62 is connected to the third control pipe d, and is connected to the first operating chamber 231 of the four-way switching valve 210 by the third control pipe d.

The third port 63 is connected to the fourth control pipe f, and is connected to the second operating chamber 232 of the four-way switching valve 210 by the fourth control pipe f.

The connection switching valve body 70 and the connection switching valve seat 60 are slidably arranged on the valve seat surface 64 in the axis L direction. The connection switching valve body 70 selectively connects the first port 61 to the second port 62 and the third port 63 by sliding on the valve seat surface 64.

The drive unit 80 drives the connection switching valve body 70 so as to slide in the axis L direction. The drive unit 80 magnetizes the stator 82 and the plunger 83 by the coil 81 in response to a control signal from a control device (not shown), and demagnetizes the stator 82 and the plunger 83. In this embodiment, when the control signal is on, the coil 81 is energized to magnetize the stator 82 and the plunger 83, and when the control signal is off, the coil 81 is energized to stop the stator 82 and the plunger 83. The magnetization of 83 is released.

When the stator 82 and the plunger 83 are magnetized, the plunger 83 is attracted to the stator 82 and moved to the other end 10b side, and the connection switching valve body 70 connected to the plunger 83 by the drive shaft 84 It is slid to the other end 10b side. When the connection switching valve body 70 is slid toward the other end 10b side, the first port 61 and the second port 62 are connected, and the third port 63 and the first pilot chamber 11 are connected.

When the magnetization of the stator 82 and the plunger 83 is released, the plunger 83 is moved to one end 10a side by the pressing spring 85, and the connection switching valve body 70 connected to the plunger 83 by the drive shaft 84 is at one end. It is slid to the 10a side. When the connection switching valve body 70 is slid toward one end 10a, the first port 61 and the third port 63 are connected, and the second port 62 and the first pilot chamber 11 are connected.

Next, an example of the operation of the pilot valve 1 in the air conditioning system 300 will be described with reference to FIGS. 2 to 6.

During the heating operation of the air conditioning system 300, the four-way switching valve 350 for switching the flow direction is in the heating direction. Therefore, the low-pressure refrigerant flows through the switching input / output port pC, and the low-pressure refrigerant is introduced from the switching input / output port pC into the third pilot chamber 13 through the second control pipe b. A low-pressure refrigerant is also introduced into the second control pipe e. Further, since the on-off valve 360 is closed, the refrigerant pressure in the discharge side high pressure port pA and the main valve chamber 212 of the four-way switching valve 210 for defrosting operation becomes low pressure (low pressure refrigerant), and from the discharge side high pressure port pA. The low pressure refrigerant is introduced into the second pilot chamber 12 through the fifth control pipe g. As a result, the differential pressure between the refrigerant pressure in the second pilot chamber 12 and the refrigerant pressure in the third pilot chamber 13 is eliminated, and as shown in FIG. 2, the second valve body 50 comes into contact with the second valve seat 48 and is first. The valve body 30 separates from the first valve seat 47. Therefore, the third pilot chamber 13 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44, and the low-pressure refrigerant is introduced into the first pilot chamber 11. Since the low-pressure refrigerant is introduced into the second control pipe e and the first pilot chamber 11, the first of the four-way switching valve 210 for defrosting operation is passed through the third control pipe d and the fourth control pipe f. The low pressure refrigerant is introduced into the working chamber 231 and the second working chamber 232. In this way, the low-pressure refrigerant is introduced into the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232 of the four-way switching valve 210, and is in the first distribution state.

Next, when the defrosting operation is started during the heating operation of the cooling / heating system 300, the on-off valve 360 changes from the closed state to the open state. When the on-off valve 360 is opened, the high-pressure refrigerant is introduced into the main valve chamber 212 through the discharge-side high-pressure port pA of the four-way switching valve 210 for defrosting operation, and the high-pressure refrigerant is introduced from the discharge-side high-pressure port pA through the fifth control pipe g. 2 A high-pressure refrigerant is introduced into the pilot chamber 12. When the high-pressure refrigerant is introduced into the second pilot chamber 12, the refrigerant pressure rises and changes from low pressure to medium pressure (medium pressure refrigerant). At this time, the second pilot chamber 12 and the third pilot chamber 13 are connected by the pressure equalizing hole 31, but the flow path area of the pressure equalizing hole 31 is sufficiently smaller than the flow path area of the fifth control pipe g. Further, since the refrigerant flowing into the third pilot chamber 13 through the pressure equalizing hole 31 flows out from the second control pipe b to the low pressure side, the refrigerant pressure in the second pilot chamber 12 becomes higher than the refrigerant pressure in the third pilot chamber 13. Differential pressure is generated. Due to this differential pressure, the first valve body 30 and the second valve body 50 move to the one end portion 10a side. As a result of this movement, as shown in FIG. 3, the opening 31a of the pressure equalizing hole 31 is closed by the movable portion 42 of the second partition member 40, and the flow of the refrigerant from the second pilot chamber 12 to the third pilot chamber 13 flows. Stop. Further, the refrigerant pressure in the first pilot chamber 11 temporarily becomes a medium pressure (medium pressure refrigerant).

Further, due to the differential pressure, the first valve body 30 and the second valve body 50 move to the one end portion 10a side, and as shown in FIG. 4, the first valve body 30 comes into contact with the first valve seat 47. The two-valve body 50 separates from the second valve seat 48. Therefore, the fourth pilot chamber 14 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44, and the high-pressure refrigerant is introduced into the first pilot chamber 11. At this time, when the control signal of the drive unit 80 is turned off, as shown in FIG. 4, the connection switching valve body 70 is slid toward one end portion 10a, and the first pilot chamber 11 through the third control pipe d. The high-pressure refrigerant is introduced into the operating chamber 231 and the low-pressure refrigerant is introduced from the second control pipe e through the fourth control pipe f into the second operating chamber 232, and the four-way switching valve 210 is in the second distribution state. Alternatively, when the control signal of the drive unit 80 is turned on, as shown in FIG. 5, the connection switching valve body 70 is slid toward the other end portion 10b, and the first control tube e passes through the third control tube d. The low-pressure refrigerant is introduced into the operating chamber 231 and the high-pressure refrigerant is introduced from the first pilot chamber 11 into the second operating chamber 232 through the fourth control pipe f, and the four-way switching valve 210 is in the third distribution state.

(During defrosting operation: 2nd distribution state, 3rd distribution state)
When the four-way switching valve 210 for defrosting operation is in the second flow state or the third flow state, the refrigerant flows from the discharge side high pressure port pA to either the first inlet / output port pB1 or the second inlet / output port pB2, so that the refrigerant is discharged. The refrigerant pressure at the side high-pressure port pA decreases to medium pressure (medium-pressure refrigerant) (FIGS. 4 and 5). Therefore, the medium-pressure refrigerant is introduced into the second pilot chamber 12 through the fifth control pipe g, but since the pressure of this medium-pressure refrigerant is higher than that of the low-pressure refrigerant in the third pilot chamber 13, the first valve body 30 is the first. The state of being in contact with the valve seat 47 and the second valve body 50 being separated from the second valve seat 48 is maintained. Therefore, the second distribution state or the third distribution state is maintained.

(End of defrosting operation: Transition period from 2nd and 3rd distribution state to 1st distribution state)
Next, when the defrosting operation is completed during the heating operation of the cooling / heating system 300, the on-off valve 360 changes from the valve open state to the valve closed state. When the on-off valve 360 is closed, the introduction of the high-pressure refrigerant (or medium-pressure refrigerant) into the main valve chamber 212 through the discharge-side high-pressure port pA of the four-way switching valve 210 for defrosting operation is stopped, and the discharge-side high pressure is stopped. The refrigerant pressures of the port pA and the main valve chamber 212 decrease to a low pressure (low pressure refrigerant), and the refrigerant pressure of the second pilot chamber 12 also decreases from the discharge side high pressure port pA through the fifth control pipe g. Further, when the refrigerant in the second pilot chamber 12 flows into the third pilot chamber 13 through the pressure equalizing hole 31, the refrigerant pressure in the second pilot chamber 12 also decreases. As a result, the differential pressure between the refrigerant pressure in the second pilot chamber 12 and the refrigerant pressure in the third pilot chamber 13 is eliminated, and as shown in FIG. 2, the second valve body 50 comes into contact with the second valve seat 48 and is first. The valve body 30 separates from the first valve seat 47. Therefore, the third pilot chamber 13 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44, and the low-pressure refrigerant is introduced into the first pilot chamber 11. Since the low-pressure refrigerant is introduced into the second control pipe e and the first pilot chamber 11, the first operation of the four-way switching valve 210 for defrosting operation is performed through the third control pipe d and the fourth control pipe f. The low pressure refrigerant is introduced into the chamber 231 and the second operating chamber 232. Therefore, the low-pressure refrigerant is introduced into the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232 of the four-way switching valve 210, and is in the first distribution state.

(During cooling operation: 4th distribution state)
During the cooling operation of the cooling / heating system 300, the four-way switching valve 350 for switching the flow direction is in the cooling direction, so that the high-pressure refrigerant flows to the switching input / output port pC, and the third pilot chamber passes through the second control pipe b from the switching input / output port pC. A high-pressure refrigerant is introduced into 13. A high-pressure refrigerant is also introduced into the second control pipe e. Further, since the on-off valve 360 is opened, the high-pressure refrigerant is introduced into the main valve chamber 212 through the discharge-side high-pressure port pA of the four-way switching valve 210 for defrosting operation, and the fifth control pipe is introduced from the discharge-side high-pressure port pA. A high-pressure refrigerant is introduced into the second pilot chamber 12 through g. As a result, the differential pressure between the refrigerant pressure in the second pilot chamber 12 and the refrigerant pressure in the third pilot chamber 13 disappears, and as shown in FIG. 6, the second valve body 50 comes into contact with the second valve seat 48 and is the first. The valve body 30 separates from the first valve seat 47. Therefore, the third pilot chamber 13 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44, and the high-pressure refrigerant is introduced into the first pilot chamber 11. Since the high-pressure refrigerant is introduced into the second control pipe e and the first pilot chamber 11, the first operation of the four-way switching valve 210 for defrosting operation is performed through the third control pipe d and the fourth control pipe f. A high-pressure refrigerant is introduced into the chamber 231 and the second operating chamber 232. Therefore, the high-pressure refrigerant is introduced into the main valve chamber 212, the first operating chamber 231 and the second operating chamber 232 of the four-way switching valve 210, and is in the fourth distribution state.

FIG. 7 shows a table summarizing the relationship between the operating state of the air conditioning system 300 and the states of the four-way switching valve 350 for switching the flow direction, the four-way switching valve 210 for defrosting operation, the on-off valve 360, and the pilot valve 1.

The pilot valve 1 of the above-described embodiment is
The first control pipe a connected to the discharge port 310a of the compressor 310,
The second control pipes b and e that are connected to the discharge port 310a of the compressor 310 during the cooling operation and are connected to the suction port 310b of the compressor 310 during the heating operation.
A third control tube d connected to the first operating chamber 231 and
The fourth control tube f connected to the second operating chamber 232 and
It has a fifth control pipe g connected to the discharge port 310a of the compressor 310 via an on-off valve 360.

In addition, the pilot valve 1
A tubular valve body 10 in which the first pilot chamber 11, the second pilot chamber 12, the third pilot chamber 13, and the fourth pilot chamber 14 are arranged in order in the L direction of the axis, and
A first partition member 20 arranged inside the valve body 10 so as to partition the first pilot chamber 11 and the second pilot chamber 12,
A first valve body 30 arranged so as to be movable in the axis L direction inside the valve body 10 so as to partition the second pilot chamber 12 and the third pilot chamber 13.
A second partition member 40 arranged inside the valve body 10 so as to partition the third pilot chamber 13 and the fourth pilot chamber 14,
A second valve body 50 movably arranged in the fourth pilot chamber 14 in the L direction of the axis, and
A first connection flow path 43 that penetrates the second partition member 40 in the L direction of the axis and connects the third pilot chamber 13 and the fourth pilot chamber 14.
A second connection flow path 44 connecting the first connection flow path 43 and the first pilot chamber 11 and
A first valve seat 47 that surrounds the opening on the third pilot chamber 13 side in the first connection flow path 43 and is provided so that the opening is opened and closed when the first valve body 30 is brought into contact with and separated from each other.
A second valve seat 48 that surrounds the opening on the side of the fourth pilot chamber 14 in the first connection flow path 43 and is provided so that the opening is opened and closed when the second valve body 50 is brought into contact with and separated from each other.
The connection switching valve body 70 arranged in the first pilot chamber 11 and
It has a drive unit that drives the connection switching valve body 70.

And the pilot valve 1
A fifth control tube g is connected to the second pilot chamber 12, and a fifth control tube g is connected to the second pilot chamber 12.
A second control pipe b is connected to the third pilot chamber 13.
A first control tube a is connected to the fourth pilot chamber 14.
The first valve body 30 and the second valve body 50 are connected by an operating rod 38 inserted into the first connecting flow path 43, and are connected to each other.
When the on-off valve 360 is in the open state during the cooling operation, the refrigerant pressure in the second pilot chamber 12 and the refrigerant pressure in the third pilot chamber 13 are both high pressure and there is no differential pressure, and the first valve body 30 is the first valve seat. Apart from 47, the second valve body 50 is in contact with the second valve seat 48, and the third pilot chamber 13 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44. As a result, the third control tube d and the fourth control tube f are connected to the second control tubes b and e (fourth distribution state).
When the on-off valve 360 is closed during the heating operation, the refrigerant pressure in the second pilot chamber 12 and the refrigerant pressure in the third pilot chamber 13 are both low pressure and there is no differential pressure, and the first valve body 30 is the first valve seat. Apart from 47, the second valve body 50 is in contact with the second valve seat 48, and the third pilot chamber 13 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44. As a result, the third control tube d and the fourth control tube f are connected to the second control tubes b and e (first distribution state).
When the on-off valve 360 is in the open state during the heating operation, the refrigerant pressure (high pressure or medium pressure) of the second pilot chamber 12 becomes higher than the refrigerant pressure (low pressure) of the third pilot chamber 13, and the first valve body 30 is the first. The second valve body 50 is in contact with the first valve seat 47 and is separated from the second valve seat 48, and the fourth pilot chamber 14 is connected to the first pilot chamber 11 via the first connection flow path 43 and the second connection flow path 44. The drive unit 80 is connected to connect the third control tube d and the first pilot chamber 11 (that is, the first control tube a) and the fourth control tube f and the second control tube e according to the control signal. (Second distribution state), or the third control tube d and the second control tube e are connected, and the fourth control tube f and the first pilot chamber 11 (that is, the first control tube a) are connected. (Third distribution state), the connection switching valve body 70 is driven.

Since the pilot valve 1 is configured in this way, the pilot valve 1 alone is in the first distribution state, the second distribution state, the third distribution state, and the fourth distribution state without using a plurality of pilot valves. As described above, the four-way switching valve 210 for defrosting operation can be controlled. Therefore, it is possible to control the four-way switching valve 210 capable of a large number of flow path switching patterns without increasing the number of parts.

Although examples of the present invention have been described above, the present invention is not limited to these examples. As long as the gist of the present invention is not contrary to the above-described embodiment, those skilled in the art appropriately adding, deleting, or changing the design, or combining the features of the examples as appropriate are also present inventions. Is included in the range of.

1 ... Piston valve, 10 ... Valve body, 10a ... One end, 10b ... The other end, 11 ... First pilot room, 12 ... Second pilot room, 13 ... Third pilot room, 14 ... Fourth pilot room, 15 ... Cap, 20 ... 1st partition member, 30 ... 1st valve body, 31 ... Pressure equalizing hole, 31a ... Opening, 35 ... 1st valve closing spring, 38 ... Actuating rod, 40 ... 2nd partition member, 41 ... Partition Main body, 42 ... movable part, 43 ... first connection flow path, 44 ... second connection flow path, 45 ... pressing spring, 47 ... first valve seat, 48 ... second valve seat, 50 ... second valve body, 55 ... 2nd valve closing spring, 60 ... Connection switching valve seat, 61 ... 1st port, 62 ... 2nd port, 63 ... 3rd port, 64 ... Valve seat surface, 70 ... Connection switching valve body, 80 ... Drive unit , 81 ... coil, 82 ... stator, 83 ... plunger, 84 ... drive shaft, 85 ... pressing spring, a ... first control tube, b, e ... second control tube, d ... third control tube, f ... 4th control pipe, g ... 5th control pipe, L ... Axial line 210 ... Four-way switching valve, 211 ... Main valve housing, 212 ... Main valve chamber, 214 ... Inner cylinder member, 221 ... 1st piston, 222 ... 2nd piston , 231 ... 1st operating chamber, 232 ... 2nd operating chamber, 241A ... 1st high pressure side valve seat, 241B ... 1st switching port side valve seat, 242A ... 2nd switching port side valve seat, 242B ... 2nd high pressure side Valve seat, 245 ... Left cylindrical valve seat, 246 ... Right cylindrical valve seat, 251 ... First valve body, 251A ... Left valve body, 251B ... Right valve body, 252 ... Second valve body, 252A ... Left valve body, 252B ... Right valve, 261 ... 1st stem, 262 ... 2nd stem, pA ... Discharge side high pressure port, pB1 ... 1st inlet / output port, pB2 ... 2nd inlet / output port, pC ... Switching input / output Port 300 ... Air conditioning system, 310 ... Compressor, 310a ... Discharge port, 310b ... Suction port, 320 ... Indoor heat exchanger, 331 ... First outdoor heat exchanger, 332 ... Second outdoor heat exchanger, 340 ... Expansion valve , 350 ... four-way switching valve, 360 ... on-off valve

Claims (4)

A pilot valve used to control a four-way switching valve that switches the flow state of the refrigerant in the first outdoor heat exchanger and the second outdoor heat exchanger of the air conditioning system.
The four-way switching valve has a main valve chamber connected to the discharge port of the compressor of the air conditioning system via an on-off valve, and a first operating chamber and a second operating chamber partitioned from the main valve chamber. , The flow state is switched according to the refrigerant pressures of the main valve chamber, the first operating chamber and the second operating chamber.
The pilot valve
The first control pipe connected to the discharge port of the compressor and
A second control pipe connected to the discharge port of the compressor during the cooling operation and connected to the suction port of the compressor during the heating operation.
A third control tube connected to the first operating chamber and
The fourth control pipe connected to the second operating chamber and
It has a fifth control pipe connected to the discharge port of the compressor via the on-off valve.
When the on-off valve is in the open state during the cooling operation, the third control pipe, the fourth control pipe, and the second control pipe are connected to each other.
When the on-off valve is closed during the heating operation, the third control pipe, the fourth control pipe, and the second control pipe are connected to each other.
When the on-off valve is in the open state during the heating operation, the third control pipe and the first control pipe are connected and the fourth control pipe and the second control pipe are connected in response to the control signal. Alternatively, the pilot valve is configured to connect the third control pipe and the second control pipe and connect the fourth control pipe and the first control pipe. A tubular valve body in which the first pilot chamber, the second pilot chamber, the third pilot chamber, and the fourth pilot chamber are arranged in order in the axial direction, and
A first partition member arranged inside the valve body so as to partition the first pilot chamber and the second pilot chamber, and
A first valve body movably arranged inside the valve body so as to partition the second pilot chamber and the third pilot chamber, and a first valve body.
A second partition member arranged inside the valve body so as to partition the third pilot chamber and the fourth pilot chamber, and
A second valve body movably arranged in the fourth pilot chamber in the axial direction,
A first connection flow path that penetrates the second partition member in the axial direction and connects the third pilot chamber and the fourth pilot chamber.
A second connection flow path connecting the first connection flow path and the first pilot chamber,
A first valve seat that surrounds the opening on the third pilot chamber side in the first connection flow path and is provided so that the opening is opened and closed when the first valve body is brought into contact with each other.
A second valve seat that surrounds the opening on the side of the fourth pilot chamber in the first connection flow path and is provided so that the opening is opened and closed when the second valve body is brought into contact with each other.
The connection switching valve body arranged in the first pilot chamber and
It has a drive unit that drives the connection switching valve body, and has
The fifth control pipe is connected to the second pilot chamber.
The second control pipe is connected to the third pilot chamber.
The first control pipe is connected to the fourth pilot chamber.
The first valve body and the second valve body are connected by an operating rod inserted into the first connection flow path.
When the on-off valve is in the open state during the cooling operation, the first valve body is separated from the first valve seat and the second valve body is in contact with the second valve seat.
When the on-off valve is closed during the heating operation, the first valve body is separated from the first valve seat and the second valve body is in contact with the second valve seat.
When the on-off valve is in the open state during the heating operation, the first valve body is in contact with the first valve seat, the second valve body is separated from the second valve seat, and the drive unit receives the control signal. Correspondingly, the third control pipe and the first pilot chamber are connected and the fourth control pipe and the second control pipe are connected, or the third control pipe and the second control pipe are connected. The pilot valve according to claim 1, wherein the connection switching valve body is connected and drives the connection switching valve body so as to connect the fourth control pipe and the first pilot chamber. The first valve body is provided with a pressure equalizing hole for connecting the second pilot chamber and the third pilot chamber.
The pilot valve according to claim 2, wherein the pressure equalizing hole is configured to be closed before the first valve body comes into contact with the first valve seat. The first control pipe into which the high-pressure refrigerant is introduced and
The second control tube and
With the third control tube
4th control tube and
Has a fifth control tube,
When the high-pressure refrigerant is introduced into the second control pipe and the fifth control pipe, the third control pipe, the fourth control pipe, and the second control pipe are connected to each other.
When the low-pressure refrigerant is introduced into the second control pipe and the fifth control pipe, the third control pipe, the fourth control pipe, and the second control pipe are connected to each other.
When the low pressure refrigerant is introduced into the second control pipe and the high pressure refrigerant or the medium pressure refrigerant is introduced into the fifth control pipe, the third control pipe and the first control pipe are arranged according to the control signal. And the 4th control tube and the 2nd control tube are connected, or the 3rd control tube and the 2nd control tube are connected, and the 4th control tube and the 1st control tube are connected. A pilot valve characterized in that it is configured to connect.

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