JP7280631B2 - Flow switching valve - Google Patents

Description

The present invention relates to a pilot type flow path switching valve.

An example of a conventional flow path switching valve is disclosed in Patent Document 1. This flow path switching valve is incorporated, for example, in the refrigeration cycle of an air conditioner, and operates when the refrigerant flow path is switched. The channel switching valve has a four-way valve as a main valve and a three-way switching valve as a pilot valve.

The four-way valve has a cylindrical valve body. Both ends of the valve body are closed with lid members. A valve seat, a valve body, a first piston, and a second piston are arranged inside the valve body. A valve seat is positioned between the first and second pistons. The inner space of the valve body includes a valve chamber between the first piston and the second piston, a first working chamber between the first piston and one lid member, and a space between the second piston and the other lid member. and a second working chamber between. The first piston and the second piston are connected to each other by a connecting body. The connecting body is fitted with the valve body. The valve body is formed with an inlet port facing the valve seat. A first port, an outlet port, and a second port are formed on the valve seat surface of the valve seat. High pressure refrigerant flows through the inlet port and low pressure refrigerant flows through the outlet port. The valve body slides on the valve seat surface and connects the first port and the outlet port or connects the second port and the outlet port.

A three-way switching valve is connected to the four-way valve. The three-way switching valve switches between a connection passage (first connection passage) connecting the outlet port and the first working chamber and a connection passage (second connection passage) connecting the outlet port and the second working chamber. The valve chest is connected with the inlet port. When switched to the first connection passage by the three-way switching valve, the differential pressure between the valve chamber and the first working chamber causes the first piston and the second piston to move toward the one lid member, and the valve body moves toward the one lid member. slide to the side. The valve body connects the first port and the outlet port, and the valve chamber connects the inlet port and the second port. Alternatively, when switched to the second connection passage by the three-way switching valve, the differential pressure between the valve chamber and the second working chamber causes the first piston and the second piston to move toward the other lid member, and the valve body moves to the other side. It is slid to the cover member side. The valve body connects the second port and the outlet port, and the valve chamber connects the inlet port and the first port. The first piston has a throttle passage connecting the valve chamber and the first working chamber. The second piston has a throttle passage connecting the valve chamber and the second working chamber. The four-way valve circulates the refrigerant between the valve chamber and the first working chamber and circulates the refrigerant between the valve chamber and the second working chamber through each throttle passage.

Japanese Utility Model Laid-Open No. 62-39074

In the four-way valve described above, when the connection between the first port and the second port is switched with the sliding of the valve body, there is a risk of noise caused by the flow of the refrigerant. Noise is reduced by lowering the rotation speed of the compressor to lower the pressure of the refrigerant introduced into the valve chamber from the inlet port and slowing the slide of the valve body (that is, the moving speed of the first and second pistons). can be suppressed. However, there is a problem that the control of the refrigeration cycle becomes complicated because it is necessary to reduce the rotational speed of the compressor before switching the flow path by the four-way valve and to increase the rotational speed of the compressor after switching the flow path. In addition, it takes a relatively long time of about 1 to 3 minutes to lower the rotation speed of the compressor, and a similar amount of time is required to raise the rotation speed of the compressor. Therefore, there is a problem that preparation time is required before and after switching the flow path of the four-way valve.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a flow path switching valve capable of suppressing noise without lowering the pressure of the refrigerant introduced into the valve chamber.

The inventors of the present invention have focused on the throttle passages and the connection passages that connect the outlet ports and working chambers of the first and second pistons of the flow path switching valve, and found that the minimum diameter of the throttle passages and the minimum diameter of the connection passages are Using a plurality of flow path switching valves with different ratios of , experiments on flow path switching were repeatedly conducted. As a result of intensive study of the experimental results, the present inventors found that the ratio of the minimum diameter of the throttle passage to the minimum diameter of the connection passage, the differential pressure between the valve chamber and the working chamber, and the first The inventors found the relationship between the time required for the movement of the piston and the second piston (channel switching time), and arrived at the present invention.

In order to achieve the above object, a flow path switching valve according to one aspect of the present invention includes:
A flow path switching valve having a main valve and a pilot valve,
The main valve
a cylindrical valve body with one end and the other end closed;
a valve seat disposed inside the valve body;
a first piston disposed between one end of the valve body and the valve seat;
a second piston disposed between the other end of the valve body and the valve seat;
a main valve body arranged on a valve seat surface of the valve seat and slid in the axial direction of the valve body together with the first piston and the second piston;
The inner space of the valve body includes a valve chamber between the first piston and the second piston, a first working chamber between one end of the valve body and the first piston, and a space between the valve body. and a second working chamber between the other end and the second piston,
the valve body having an inlet port connected to the valve chamber;
the valve seat has an outlet port connected to the U-turn passage of the main valve body;
The first piston has a first throttle passage connecting the valve chamber and the first working chamber,
the second piston has a second throttle passage connecting the valve chamber and the second working chamber;
The pilot valve is configured to switch between a first connection passage connecting the outlet port and the first working chamber and a second connection passage connecting the outlet port and the second working chamber. cage,
Da is the minimum diameter of the first throttle passage, Db is the minimum diameter of the first connection passage, and the valve chamber when the outlet port and the first working chamber are connected by the first connection passage. It is characterized by satisfying the following formula (1) where ΔP is the pressure difference with respect to the first working chamber.
Rmin≦Da/Db (1)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27

In the present invention,
It is preferable to satisfy the following formula (1A).
Rmin≦Da/Db≦Rmax (1A)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27
When 0.2 MPa ≤ ΔP < 1.0 MPa,
Rmax=(ΔP+(11.80))/11.43
When 1.0 MPa ≤ ΔP < 2.0 MPa,
Rmax=(ΔP+(12.97))/12.47
When 2.0 MPa ≤ ΔP < 3.0 MPa,
Rmax=(ΔP+(5.62))/6.35
When 3.0 MPa ≤ ΔP < 4.0 MPa,
Rmax=(ΔP+(2.48))/4.04
When 4.0 MPa ≤ ΔP < 5.0 MPa,
Rmax=(ΔP+(0.90))/3.05
When 5.0 MPa ≤ ΔP < 6.0 MPa,
Rmax = (ΔP + (-1.23)) / 1.95
When 6.0 MPa ≤ ΔP < 7.0 MPa,
Rmax = (ΔP + (-3.28)) / 1.11
When 7.0 MPa ≤ ΔP < 8.0 MPa,
Rmax = (ΔP + (-5.22)) / 0.53
When 8.0 MPa ≤ ΔP ≤ 10.0 MPa,
Rmax = (ΔP + (-5.99)) / 0.38

In the present invention,
It is preferable to satisfy the following formula (1B).
Rmin≦Da/Db≦Rmax (1B)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27
When 0.2 MPa ≤ ΔP < 1.0 MPa,
Rmax=(ΔP+(15.80))/16.00
When 1.0 MPa ≤ ΔP < 2.0 MPa,
Rmax=(ΔP+(14.41))/14.67
When 2.0 MPa ≤ ΔP < 3.0 MPa,
Rmax=(ΔP+(6.96))/8.01
When 3.0 MPa ≤ ΔP < 4.0 MPa,
Rmax=(ΔP+(3.56))/5.28
When 4.0 MPa ≤ ΔP < 5.0 MPa,
Rmax=(ΔP+(1.85))/4.08
When 5.0 MPa ≤ ΔP < 6.0 MPa,
Rmax = (ΔP + (-0.48)) / 2.69
When 6.0 MPa ≤ ΔP < 7.0 MPa,
Rmax = (ΔP + (-2.73)) / 1.60
When 7.0 MPa ≤ ΔP < 8.0 MPa,
Rmax = (ΔP + (-4.83)) / 0.81
When 8.0 MPa ≤ ΔP ≤ 10.0 MPa,
Rmax = (ΔP + (-5.50)) / 0.64

In the present invention,
said first piston and said second piston each having a metal part;
A through hole formed in the metal part is a portion where the first throttle passage has a minimum diameter,
It is preferable that a portion where the diameter of the second throttle passage is the smallest is a through hole formed in the metal part.

In the present invention,
The minimum diameter of the second throttle passage is the same as the minimum diameter Da of the first throttle passage,
the minimum diameter of the second connection passage is the same as the minimum diameter Db of the first connection passage;
Da is the minimum diameter of the second throttle passage, Db is the minimum diameter of the second connection passage, and the valve chamber when the outlet port and the second working chamber are connected by the second connection passage. It is preferable that the above formula (1) is satisfied, where ΔP is the pressure difference with respect to the second working chamber.

According to the present invention, the ratio Da/Db between the minimum diameter Da of the first throttle passage of the first piston and the minimum diameter Db of the first connection passage connecting the outlet port and the first working chamber is expressed by the above formula. (1) is satisfied. With this configuration, the time required for the movement of the first piston and the second piston (flow path switching time) at the time of flow path switching can be set to a time during which noise can be suppressed. The ratio between the minimum diameter of the second throttle passage of the second piston and the minimum diameter of the second connection passage connecting the outlet port and the second working chamber can be similarly determined by satisfying the above formula (1). In addition, the channel switching time can be set to a time during which noise can be suppressed. Therefore, the flow path switching valve according to the present invention can suppress noise without lowering the pressure of the refrigerant introduced into the valve chamber.

1 is a cross-sectional view of a flow path switching valve according to one embodiment of the present invention; FIG. FIG. 3 is a cross-sectional view showing another state of the flow path switching valve of FIG. 1; 2 is an enlarged cross-sectional view of a part of the main valve of the flow path switching valve of FIG. 1; FIG. 3 is a cross-sectional view enlarging a part of the main valve of the flow path switching valve of FIG. 2; FIG. 2 is an enlarged cross-sectional view of a part of the pilot valve of the flow path switching valve of FIG. 1; FIG. 2 is a graph showing the relationship between the ratio of the minimum diameter of the first throttle passage to the minimum diameter of the first connection passage in the flow path switching valve of FIG. 1 and the differential pressure between the valve chamber and the first working chamber. In the flow path switching valve of FIG. 1, the ratio of the minimum diameter of the first throttle passage to the minimum diameter of the first connection passage that can suppress noise and provide a short flow path switching time, the valve chamber and the first working chamber is a diagram showing the differential pressure of and the range of . In the flow path switching valve of FIG. 1, the ratio of the minimum diameter of the first throttle passage to the minimum diameter of the first connection passage that can suppress noise and shorten the flow path switching time, the valve chamber and the first working chamber 1 is a diagram showing the range of differential pressure between and .

A channel switching valve according to an embodiment of the present invention will be described below with reference to FIGS. 1 to 8. FIG.

1 and 2 are cross-sectional views of a flow path switching valve according to one embodiment of the present invention. 1 shows the main valve body in the first main valve body position, and FIG. 2 shows the main valve body in the second main valve body position. In FIGS. 1 and 2, connecting pipes between the main valve and the pilot valve are schematically shown, and aa, bb, and cc are connected, respectively. 3 is a cross-sectional view enlarging a part of the main valve of the flow path switching valve shown in FIG. 1. FIG. FIG. 3 is an enlarged sectional view of the first piston of the main valve. 4 is a cross-sectional view enlarging a part of the main valve of the flow path switching valve shown in FIG. 2. FIG. FIG. 4 is an enlarged cross-sectional view of the second piston of the main valve. 5 is a cross-sectional view enlarging a part of the pilot valve of the flow path switching valve of FIG. 1. FIG. FIG. 5 is an enlarged sectional view of a valve seat of the pilot valve. 6 is a graph showing the relationship between the ratio of the minimum diameter of the first throttle passage to the minimum diameter of the first connection passage in the flow path switching valve of FIG. 1 and the differential pressure between the valve chamber and the first working chamber; is. 7 and 8 show, in the flow path switching valve of FIG. FIG. 10 is a diagram showing the range of differential pressure between the chamber and the first working chamber; FIG. 7 shows a range in which the channel switching time is 1.1 to 60 seconds. FIG. 8 shows a range in which the channel switching time is 1.1 to 30 seconds.

As shown in FIGS. 1 and 2, the flow path switching valve 1 according to this embodiment has a main valve 10 and a pilot valve 110 .

The main valve 10 has a valve body 20 , a valve seat 30 , a main valve body 40 , a first piston 50 , a second piston 60 and a connecting body 70 .

The valve body 20 has a cylindrical shape. The axial direction of the valve body 20 coincides with the left-right direction in FIGS. One end of the valve body 20 (the left end in FIGS. 1 and 2) is closed with a first lid member 21 . The other end of the valve body 20 (the right end in FIGS. 1 and 2) is closed with a second lid member 22 . The first lid member 21 has a first connection port 21a. The second lid member 22 has a second connection port 22a. The valve body 20 has an inlet port 23 . The inlet port 23 is located at an axially central location in the upper portion of the valve body 20 . An inlet conduit 83 is connected to the inlet port 23 .

The valve seat 30 is arranged on the inside of the valve body 20 at the axially central portion of the lower portion of the valve body 20 . The valve seat 30 has a valve seat surface 30a facing upward. The valve seat 30 has a first port 31, an outlet port 33, and a second port 32 which are arranged in order from the first lid member 21 side to the second lid member 22 side. The first port 31, the outlet port 33, and the second port 32 are open to the valve seat surface 30a. A first conduit 91 is connected to the first port 31 . An outlet conduit 93 is connected to the outlet port 33 . A second conduit 92 is connected to the second port 32 . The valve body 20, the first lid member 21, the second lid member 22 and the valve seat 30 are made of metal such as stainless steel.

The main valve body 40 has a substantially semi-elliptical shape. The main valve body 40 has a U-turn passage 41 inside. The U-turn passage 41 is separated from the valve chamber 13, which will be described later. The main valve body 40 is arranged on the valve seat surface 30a. The main valve body 40 is slid on the valve seat surface 30a until the U-turn passage 41 connects the first port 31 and the outlet port 33 to the first main valve body position (of the main valve body 40 shown in FIG. 1). position) and a second main valve body position (the position of the main valve body 40 shown in FIG. 2) where the U-turn passage 41 connects the second port 32 and the outlet port 33 . Outlet port 33 is always connected to U-turn passage 41 . The main valve body 40 is made of synthetic resin such as polyphenylene sulfide (PPS), for example.

The first piston 50 is arranged inside the valve body 20 between the first lid member 21 and the valve seat 30 . The first piston 50 is movable in the axial direction of the valve body 20 . The first piston 50 defines the inner space of the valve body 20 in the axial direction. The first piston 50 has discs 51 and 52 , a leaf spring member 53 , a packing 54 , a valve body support member 55 , a valve body 56 and a compression coil spring 58 . The discs 51 and 52 are made of metal such as stainless steel. The outer diameter of disc 51 is slightly smaller than the inner diameter of valve body 20 . The outer diameter of disc 52 is smaller than the outer diameter of disc 51 . The leaf spring member 53 is a metal component. The leaf spring member 53 has a disc portion 53a and a plurality of spring pieces 53b connected to the periphery of the disc portion 53a. The packing 54 is made of synthetic resin such as polytetrafluoroethylene (PTFE). The packing 54 has a circular tray shape. The packing 54 has a disk-shaped bottom wall portion 54a and a peripheral wall portion 54b connected to the peripheral edge of the bottom wall portion 54a. A leaf spring member 53 is arranged inside the packing 54 . The disk portion 53a of the leaf spring member 53 and the bottom wall portion 54a of the packing 54 are in contact with each other. The discs 51 and 52 are fastened with bolts (not shown), and the disc portion 53a of the leaf spring member 53 and the bottom wall portion 54a of the packing 54 are held between the discs 51 and 52. As shown in FIG. A plurality of spring pieces 53b of the plate spring member 53 press the peripheral wall portion 54b of the packing 54 from the inside toward the outside. A peripheral wall portion 54 b of the packing 54 is in contact with the inner peripheral surface of the valve body 20 . The valve body support member 55 is made of metal such as brass. The valve support member 55 has a disk portion 55a and a protrusion 55b. The disk portion 55a is joined to the surface of the disk 51 on the side of the first lid member 21 . The protrusion 55b is arranged at the center of the disc portion 55a. The valve body 56 is made of synthetic resin such as PPS. The valve body 56 has a cylindrical shape. The valve body 56 is supported by the protrusion 55 b of the valve body support member 55 so as to be movable in the axial direction of the valve body 20 . A base end portion 56a of the valve body 56 is arranged inside the protrusion 55b. A tip portion 56b of the valve body 56 protrudes outside the protrusion 55b. A base end portion 56 a of the valve body 56 is pressed against the packing 54 by a compression coil spring 58 . A tip portion 56b of the valve body 56 is formed in a substantially conical shape. The valve body 56 opens and closes the first connection port 21 a of the first lid member 21 .

The first piston 50 has a first throttle passage 57 penetrating from the first lid member 21 side to the valve seat 30 side. The passage area of the first throttle passage 57 is the smallest at the through hole 53c formed in the plate spring member 53 . The diameter of the through hole 53 c is the minimum diameter Da of the first throttle passage 57 .

The second piston 60 is arranged between the second lid member 22 and the valve seat 30 inside the valve body 20 . The second piston 60 is movable in the axial direction of the valve body 20 . The second piston 60 axially partitions the inner space of the valve body 20 . The second piston 60 has discs 61 and 62 , a leaf spring member 63 , a packing 64 , a valve body support member 65 , a valve body 66 and a compression coil spring 68 . Discs 61 and 62, a plate spring member 63 (a disc portion 63a, a plurality of spring pieces 63b, a through hole 63c), a packing 64 (bottom wall portion 64a, a peripheral wall portion 64b), and a valve support member 65 (circular Plate portion 65a, protrusion 65b), valve body 66 (base end portion 66a, tip end portion 66b), and compression coil spring 68 are composed of discs 51 and 52 of the first piston and leaf spring member 53 (circle plate portion 53a, a plurality of spring pieces 53b, through hole 53c), packing 54 (bottom wall portion 54a, peripheral wall portion 54b), valve body support member 55 (disk portion 55a, protrusion 55b), and valve body 56 (Base end portion 56a, distal end portion 56b) and the compression coil spring 58 have the same configuration. The valve body 66 opens and closes the second connection port 22 a of the second lid member 22 .

The second piston 60 has a second throttle passage 67 penetrating from the second lid member 22 side to the valve seat 30 side. The passage area of the second throttle passage 67 is the smallest at the through hole 63 c formed in the plate spring member 63 . The diameter of the through hole 63 c is the minimum diameter of the second throttle passage 67 . The diameter of the through hole 63 c is the same as the diameter of the through hole 53 c of the first piston 50 .

The connecting body 70 is a metal bracket that connects the first piston 50 and the second piston 60 . A valve body fitting hole 71 into which the main valve body 40 is fitted is formed in the connecting body 70 . The connecting body 70 slides the main valve body 40 on the valve seat surface 30a as the first piston 50 and the second piston 60 move.

The inner space of the valve body 20 includes a first working chamber 11 between the first lid member 21 and the first piston 50, a second working chamber 12 between the second lid member 22 and the second piston 60, and the valve chamber 13 between the first piston 50 and the second piston 60 . An inlet port 23 is connected to the valve chamber 13 . The valve chamber 13 and the first working chamber 11 are connected via the first throttle passage 57 of the first piston 50 . The valve chamber 13 and the second working chamber 12 are connected via a second throttle passage 67 of the second piston 60 .

The pilot valve 110 has a valve body 120, a valve seat 130, a pilot valve body 140, a fixed iron core 150 (also referred to as an "attractor"), a plunger 160, and an electromagnetic coil (not shown). .

The valve body 120 has a cylindrical shape. One end of the valve body 120 (the left end in FIGS. 1 and 2) is closed with a lid member 121 . The other end of the valve body 120 (the right end in FIGS. 1 and 2) is closed with a fixed iron core 150 . An electromagnetic coil (not shown) is arranged outside the valve body 120 .

The valve seat 130 is made of metal such as stainless steel. The valve seat 130 is arranged inside the valve body 120 at a portion near the lid member 121 in the lower portion of the valve body 120 . The valve seat 130 has a valve seat surface 130a facing upward. As shown in FIG. 5, the valve seat 130 has a first port 131, a common port 133, and a second port 132 arranged in order from the lid member 121 side to the fixed core 150 side (left to right in FIG. 5). have. The first port 131, the common port 133, and the second port 132 are open to the valve seat surface 130a. The diameter of the first port 131, the diameter of the common port 133, and the diameter of the second port 132 are the same. A first connection pipe 191 is connected to the first port 131 . A common connection pipe 193 is connected to the common port 133 . A second connection pipe 192 is connected to the second port 132 .

The first connection pipe 191 connects the first port 131 and the first connection port 21 a of the first lid member 21 . A common connection tube 193 connects the common port 133 and the outlet conduit 93 . The second connection pipe 192 connects the second port 132 and the second connection port 22 a of the second lid member 22 .

Pilot valve body 140 has a rectangular parallelepiped shape. The pilot valve body 140 has a U-turn passage 141 inside. The U-turn passage 141 is separated from the inner space of the valve body 120 . The pilot valve body 140 is arranged on the valve seat surface 130a. The pilot valve body 140 is slid on the valve seat surface 130a until the U-turn passage 141 connects the first port 131 and the common port 133 to the first pilot valve body position (the position of the pilot valve body 140 shown in FIG. 1). position) and a second pilot valve body position (the position of the pilot valve body 140 shown in FIG. 2) where the U-turn passage 141 connects the second port 132 and the common port 133 . Common port 133 is always connected to U-turn passage 141 .

Fixed core 150 has a cylindrical shape. The fixed core 150 is joined to the other end of the valve body 120 .

Plunger 160 has a cylindrical shape. Plunger 160 is located inside valve body 120 . Plunger 160 is movable in the axial direction of valve body 120 . Plunger 160 is connected to pilot valve body 140 by valve shaft 170 . A plunger spring 161 is arranged between the plunger 160 and the fixed core 150 . The plunger spring 161 is a compression coil spring. A plunger spring 161 pushes the plunger 160 toward the lid member 121 .

Next, an example of the operation of the flow path switching valve 1 will be described. The flow path switching valve 1 is incorporated in the refrigeration cycle of an air conditioner, and high-pressure refrigerant flows through an inlet conduit 83 and low-pressure refrigerant flows through an outlet conduit 93 .

When the electromagnetic coil (not shown) of pilot valve 110 is not energized, fixed core 150 and plunger 160 are not magnetized, and plunger 160 is pushed by plunger spring 161 to move toward cover member 121 . Pilot valve body 140 connected to plunger 160 by valve shaft 170 is slid toward cover member 121 on valve seat surface 130a and positioned at the first pilot valve body position. A first connection passage composed of an outlet conduit 93, a common connection pipe 193, a common port 133, a U-turn passage 141, a first port 131, a first connection pipe 191, and a first connection port 21a. C1 connects the outlet port 33 and the first working chamber 11 . A high-pressure refrigerant is introduced into the valve chamber 13 from an inlet port 23 . High-pressure refrigerant is discharged from the first working chamber 11 to the outlet port 33 through which the low-pressure refrigerant flows through the first connection passage C1. High-pressure refrigerant is introduced into the first working chamber 11 from the valve chamber 13 through the first throttle passage 57 . The differential pressure between the valve chamber 13 and the first working chamber 11 causes the first piston 50 and the second piston 60 to move toward the first lid member 21 . As the first piston 50 and the second piston 60 move, the main valve body 40 slides on the valve seat surface 30a and the main valve body 40 is positioned at the first main valve body position. Thereby, the inlet port 23 and the second port 32 are connected via the valve chamber 13 , and the outlet port 33 and the first port 31 are connected via the U-turn passage 41 . The first connection port 21 a is closed by the valve body 56 of the first piston 50 and the second connection port 22 a opens to the second working chamber 12 . After the first connection port 21a is closed, the valve chamber 13, the first working chamber 11 and the second working chamber 12 are filled with high pressure refrigerant.

When the electromagnetic coil (not shown) of pilot valve 110 is energized, fixed core 150 and plunger 160 are magnetized, and plunger 160 moves toward fixed core 150 . The pilot valve body 140 connected to the plunger 160 by the valve shaft 170 is slid on the valve seat surface 130a toward the fixed core 150 and positioned at the second pilot valve body position. A second connection passage composed of an outlet conduit 93, a common connection pipe 193, a common port 133, a U-turn passage 141, a second port 132, a second connection pipe 192, and a second connection port 22a. C2 connects the outlet port 33 and the second working chamber 12 . A high-pressure refrigerant is introduced into the valve chamber 13 from an inlet port 23 . High-pressure refrigerant is discharged from the second working chamber 12 to the outlet port 33 through which the low-pressure refrigerant flows through the second connection passage C2. High-pressure refrigerant is introduced into the second working chamber 12 from the valve chamber 13 through the second throttle passage 67 . The differential pressure between the valve chamber 13 and the second working chamber 12 moves the first piston 50 and the second piston 60 toward the second cover member 22 . As the first piston 50 and the second piston 60 move, the main valve body 40 slides on the valve seat surface 30a and the main valve body 40 is positioned at the second main valve body position. Thereby, the inlet port 23 and the first port 31 are connected through the valve chamber 13 , and the outlet port 33 and the second port 32 are connected through the U-turn passage 41 . The first connection port 21 a opens to the first working chamber 11 and the second connection port 22 a is closed by the valve body 66 of the second piston 60 . After the second connection port 22a is closed, the valve chamber 13, the first working chamber 11 and the second working chamber 12 are filled with high pressure refrigerant.

In the above operation, in the flow path switching valve 1, the pressure of the refrigerant in the first working chamber 11 is reduced through the first throttle passage 57 and the pressure drop caused by the discharge of the high pressure refrigerant through the first connection passage C1. It becomes a value according to the balance with the pressure rise due to the introduction of the high-pressure refrigerant. Similarly, the pressure of the refrigerant in the second working chamber 12 is reduced due to the high pressure refrigerant being discharged through the second connection passage C2 and the high pressure refrigerant being introduced through the second throttle passage 67. It is a value according to the balance with the pressure rise due to

The first connection passage C1 has the smallest passage area at the common port 133 of the pilot valve 110 . The diameter of the common port 133 is the minimum diameter Db of the first connection passage C1. The second connection passage C2 has the smallest passage area at the common port 133 of the pilot valve 110 . The diameter of the common port 133 is also the minimum diameter of the second connection passage C2.

The flow path switching valve 1 is configured such that the ratio Da/Db between the minimum diameter Da of the first throttle passage 57 and the minimum diameter Db of the first connection passage C1 satisfies the following formula (1). ΔP is the differential pressure between the valve chamber 13 and the first working chamber 11 when the outlet port 33 and the first working chamber 11 are connected by the first connection passage C1. In addition, the flow path switching valve 1 is used in a refrigeration cycle in which the differential pressure ΔP is 0.2 MPa or more so that the first piston 50 and the second piston 60 move reliably.

Rmin≦Da/Db (1)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27

Since the ratio Da/Db satisfies the above formula (1), the time required for the movement of the first piston and the second piston at the time of flow path switching (that is, the main valve body 40 moves from the second main valve body position to the first The time for moving to the main valve body position (hereinafter referred to as "flow passage switching time T1")) can be set to 1.1 seconds or longer. If the passage switching time T1 is 1.1 seconds or more, the noise level when the main valve body 40 slides can be suppressed to 45 dB or less.

Alternatively, the flow path switching valve 1 is preferably configured such that the ratio Da/Db satisfies the following formula (1A).

Rmin≦Da/Db≦Rmax (1A)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27
When 0.2 MPa ≤ ΔP < 1.0 MPa,
Rmax=(ΔP+(11.80))/11.43
When 1.0 MPa ≤ ΔP < 2.0 MPa,
Rmax=(ΔP+(12.97))/12.47
When 2.0 MPa ≤ ΔP < 3.0 MPa,
Rmax=(ΔP+(5.62))/6.35
When 3.0 MPa ≤ ΔP < 4.0 MPa,
Rmax=(ΔP+(2.48))/4.04
When 4.0 MPa ≤ ΔP < 5.0 MPa,
Rmax=(ΔP+(0.90))/3.05
When 5.0 MPa ≤ ΔP < 6.0 MPa,
Rmax = (ΔP + (-1.23)) / 1.95
When 6.0 MPa ≤ ΔP < 7.0 MPa,
Rmax = (ΔP + (-3.28)) / 1.11
When 7.0 MPa ≤ ΔP < 8.0 MPa,
Rmax = (ΔP + (-5.22)) / 0.53
When 8.0 MPa ≤ ΔP ≤ 10.0 MPa,
Rmax = (ΔP + (-5.99)) / 0.38

When the ratio Da/Db satisfies the above formula (1A), the channel switching time T1 can be set to 1.1 seconds or more and 60 seconds or less.

Alternatively, the flow path switching valve 1 is preferably configured such that the ratio Da/Db satisfies the following formula (1B).

Rmin≦Da/Db≦Rmax (1B)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27
When 0.2 MPa ≤ ΔP < 1.0 MPa,
Rmax=(ΔP+(15.80))/16.00
When 1.0 MPa ≤ ΔP < 2.0 MPa,
Rmax=(ΔP+(14.41))/14.67
When 2.0 MPa ≤ ΔP < 3.0 MPa,
Rmax=(ΔP+(6.96))/8.01
When 3.0 MPa ≤ ΔP < 4.0 MPa,
Rmax=(ΔP+(3.56))/5.28
When 4.0 MPa ≤ ΔP < 5.0 MPa,
Rmax=(ΔP+(1.85))/4.08
When 5.0 MPa ≤ ΔP < 6.0 MPa,
Rmax = (ΔP + (-0.48)) / 2.69
When 6.0 MPa ≤ ΔP < 7.0 MPa,
Rmax = (ΔP + (-2.73)) / 1.60
When 7.0 MPa ≤ ΔP < 8.0 MPa,
Rmax = (ΔP + (-4.83)) / 0.81
When 8.0 MPa ≤ ΔP ≤ 10.0 MPa,
Rmax = (ΔP + (-5.50)) / 0.64

By setting the ratio Da/Db to satisfy the above formula (1B), the channel switching time T1 can be set to 1.1 seconds or more and 30 seconds or less.

In the flow path switching valve 1, the minimum diameter of the second throttle passage 67 is the same as the minimum diameter Da of the first throttle passage 57, and the minimum diameter of the second connection passage C2 is the maximum diameter of the first connection passage C1. It is the same as the small diameter Db. In the flow path switching valve 1, the minimum diameter of the second throttle passage 67 is Da, the minimum diameter of the second connection passage C2 is Db, and the outlet port 33 and the second working chamber 12 are connected by the second connection passage C2. When the differential pressure between the valve chamber 13 and the second working chamber 12 is .DELTA.P, the above formula (1) is satisfied. Therefore, the time required for the main valve body 40 to move from the first main valve body position to the second main valve body position (hereinafter referred to as "flow path switching time T2") should be 1.1 seconds or longer. can be done. If the passage switching time T2 is 1.1 seconds or more, the noise level when the main valve body 40 slides can be suppressed to 45 dB or less.

A flow path switching valve 1 according to this embodiment has a main valve 10 and a pilot valve 110 . The main valve 10 includes a cylindrical valve body 20 closed at one end and the other end, a valve seat 30 arranged inside the valve body 20, and a first lid member 21 closing one end of the valve body 20. and the valve seat 30, the second piston 60 disposed between the second lid member 22 that closes the other end of the valve body 20 and the valve seat 30, and the valve seat and a main valve element 40 which is arranged on a valve seat surface 30 a of the valve body 30 and slides in the axial direction of the valve body 20 together with the first piston 50 and the second piston 60 . The inner space of the valve body 20 consists of the valve chamber 13 between the first piston 50 and the second piston 60, the first working chamber 11 between the first lid member 21 and the first piston 50, and the second lid. and a second working chamber 12 between the member 22 and the second piston 60 . A valve body 20 has an inlet port 23 connected to the valve chamber 13 . A valve seat 30 has an outlet port 33 connected to the U-turn passage 41 of the main valve body 40 . The first piston 50 has a first throttle passage 57 connecting the valve chamber 13 and the first working chamber 11 . The second piston 60 has a second throttle passage 67 connecting the valve chamber 13 and the second working chamber 12 . The pilot valve 110 is configured to switch between a first connection passage C1 connecting the outlet port 33 and the first working chamber 11 and a second connection passage C2 connecting the outlet port 33 and the second working chamber 12. It is In the flow path switching valve 1, the minimum diameter of the first throttle passage 57 is Da, the minimum diameter of the first connection passage C1 is Db, and the outlet port 33 and the first working chamber 11 are connected by the first connection passage C1. When the pressure difference between the valve chamber 13 and the first working chamber 11 is ΔP, the above formula (1) is satisfied.

In the flow path switching valve 1, the ratio Da/Db between the minimum diameter Da of the first throttle passage 57 and the minimum diameter Db of the first connection passage C1 satisfies the above formula (1). By doing so, the passage switching time T1 can be set to a time during which noise can be suppressed. Therefore, the flow path switching valve 1 can suppress noise without lowering the pressure of the refrigerant introduced into the valve chamber 13 .

Also, the first piston 50 has a plate spring member 53 that is a metal component. A through hole 53 c formed in the plate spring member 53 is a portion where the first throttle passage 57 has a minimum diameter Da. The second piston 60 has a leaf spring member 63 which is a metal part. A through hole 63 c formed in the plate spring member 63 is a portion where the second throttle passage 67 has the smallest diameter. By doing so, the machining precision of the diameters of the through holes 53c and 63c can be improved compared to the case where the portion of the first throttle passage 57 having the minimum diameter Da is formed in a synthetic resin component. Therefore, the accuracy of the ratio Da/Db is improved, and the passage switching time T1 can be set to a time during which noise can be suppressed more reliably.

Also, the minimum diameter of the second throttle passage 67 is the same as the minimum diameter Da of the first throttle passage 57 . The minimum diameter of the second connection passage C2 is the same as the minimum diameter Db of the first connection passage C1. In the flow path switching valve 1, the minimum diameter of the second throttle passage 67 is Da, the minimum diameter of the second connection passage C2 is Db, and the outlet port 33 and the second working chamber 12 are connected by the second connection passage C2. When the differential pressure between the valve chamber 13 and the second working chamber 12 is .DELTA.P, the above formula (1) is satisfied. By doing so, the passage switching time T2 can be set to a time during which noise can be suppressed. Therefore, the flow path switching valve 1 can suppress noise without lowering the pressure of the refrigerant introduced into the valve chamber 13 .

The present inventors manufactured a plurality of flow path switching valves 1 having different ratios Da/Db between the minimum diameter Da of the first throttle passage 57 and the minimum diameter Db of the first connection passage C1, and Using the valve 1, the pressure difference ΔP between the valve chamber 13 and the first working chamber 11 when the outlet port 33 and the first working chamber 11 are connected by the first connection passage C1 is changed to switch the flow path. Time T1 and noise level were measured. By measuring the channel switching time T1 and the noise level, the inventors found that the noise level can be suppressed to 45 dB or less when the channel switching time T1 is 1.1 seconds or longer. . The noise level "45 dB" is the nighttime standard value for residential areas, which is stipulated in the environmental standards for noise based on the provisions of Article 16, Paragraph 1 of the Basic Environment Law. In the refrigeration cycle, a common refrigerant (eg, R410A) is often used with a differential pressure ΔP of about 1.0 to 1.5 MPa, and a carbon dioxide refrigerant is often used with a differential pressure ΔP of about 8 to 10 MPa. .

Then, based on the above measurement results, the present inventors found a graph G1_1 plotting a combination of the ratio Da/Db and the differential pressure ΔP at which the flow path switching time T1 is 1.1 seconds, and the flow path switching time T1 is A graph G30 plotting a combination of the ratio Da/Db and the differential pressure ΔP for 30 seconds, and a graph G60 plotting a combination of the ratio Da/Db and the differential pressure ΔP for a channel switching time T1 of 60 seconds. Obtained. FIG. 6 shows these graphs G1_1, G30 and G60. The inventors created approximate expressions for these graphs G1_1, G30, and G60 to obtain the above expressions (1), (1A), and (1B).

FIG. 7 shows a range SA of combinations of the ratio Da/Db and the differential pressure ΔP that satisfy the above formula (1A). By satisfying the above formula (1A), the flow path switching valve 1 can set the flow path switching time T1 to 1.1 to 60 seconds, enabling flow path switching in a short time while suppressing noise. Become.

FIG. 8 shows a range SB of combinations of the ratio Da/Db and the differential pressure ΔP that satisfy the above formula (1B). By satisfying the above formula (1B), the flow path switching valve 1 can set the flow path switching time T1 to 1.1 to 30 seconds, and can switch the flow path in a shorter time while suppressing noise. becomes. For example, in the flow path switching valve 1, when the range of possible differential pressure ΔP is 0.2 MPa to 6.0 MPa, setting the ratio Da/Db to 1.0 reduces the flow path switching time T1 to 1.0 MPa. It can be from 1 to 30 seconds.

In the above-described embodiment, when the main valve body 40 is slid between the first main valve body position and the second main valve body position, the first port 31, the outlet port 33 and the second port 32 are closed. are configured so that they are not connected at all. In addition to such a configuration, the present invention can also be used to separate the first port 31 and the outlet port 33 when the main valve body 40 is slid between the first main valve body position and the second main valve body position. and the second port 32 are all connected.

Further, in the above-described embodiments, the terms "first" and "second" are added for convenience to distinguish the constituent members, and the terms "first" and "second" are used. A configuration in which they are replaced with each other is also possible.

The pilot valve of the flow path switching valve to which the present invention can be applied is not limited to the configuration of the pilot valve 110 described above. Instead of the pilot valve 110, a switching valve that selectively connects one of the first connecting pipe 191 and the second connecting pipe 192 to the common connecting pipe 193 and closes the other that is not connected to the common connecting pipe 193 is used. can be used. "Blocking" includes not making a connection with other connecting pipes or conduits in a manner in which the refrigerant flows. Alternatively, switching to connect one of the first connecting pipe 191 and the second connecting pipe 192 to the first common connecting pipe connected to the outlet conduit 93 and connect the other to the second common connecting pipe connected to the inlet conduit 83 A valve may be used in place of pilot valve 110 .

Although embodiments of the present invention have been described above, the present invention is not limited to these examples. A person skilled in the art may add, delete, or change the design of the above-described embodiments as appropriate, or combine the features of the embodiments as appropriate, as long as they do not contradict the spirit of the present invention. included in the range of

DESCRIPTION OF SYMBOLS 1... Flow-path switching valve 10... Main valve 11... 1st operation chamber 12... 2nd operation chamber 13... Valve chamber 20... Valve body 21... First cover member 21a... First connection port, 22 Second lid member 22a Second connection port 23 Inlet port 30 Valve seat 30a Valve seat surface 31 First port 32 Second port 33 Outlet port 40 Main Valve body 41 U-turn passage 50 First piston 51, 52 Disk 53 Plate spring member 53a Disk portion 53b Spring piece 53c Through hole 54 Packing 54a Bottom wall portion 54b Peripheral wall portion 55 Valve body support member 55a Disc portion 55b Protrusion 56 Valve body 56a Base end portion 56b Tip end portion 57 First throttle passage 60... Second piston 61, 62... Disk 63... Leaf spring member 63a... Disk part 63b... Spring piece 63c... Through hole 64... Packing 64a... Bottom wall part 64b... Peripheral wall part 65...Valve disc support member 65a...Disk part 65b...Protrusion 66...Valve disc 66a...Base end part 66b...Tip part 67...Second throttle passage 70...Connector 71...Valve disc Fitting hole 83 Inlet conduit 91 First conduit 92 Second conduit 93 Outlet conduit 110 Pilot valve 120 Valve body 121 Lid member 130 Valve seat 130a Valve seat Surface 131 First port 132 Second port 133 Common port 140 Pilot valve element 141 U-turn passage 150 Fixed iron core 160 Plunger 161 Plunger spring 170 Valve shaft 191... First connection pipe, 192... Second connection pipe, 193... Common connection pipe, C1... First connection passage, C2... Second connection passage

Claims (5)

A flow path switching valve having a main valve and a pilot valve,
The main valve
a cylindrical valve body with one end and the other end closed;
a valve seat disposed inside the valve body;
a first piston disposed between one end of the valve body and the valve seat;
a second piston disposed between the other end of the valve body and the valve seat;
a main valve body arranged on a valve seat surface of the valve seat and slid in the axial direction of the valve body together with the first piston and the second piston;
The inner space of the valve body includes a valve chamber between the first piston and the second piston, a first working chamber between one end of the valve body and the first piston, and a space between the valve body. and a second working chamber between the other end and the second piston,
the valve body having an inlet port connected to the valve chamber;
the valve seat has an outlet port connected to the U-turn passage of the main valve body;
The first piston has a first throttle passage connecting the valve chamber and the first working chamber,
the second piston has a second throttle passage connecting the valve chamber and the second working chamber;
The pilot valve is configured to switch between a first connection passage connecting the outlet port and the first working chamber and a second connection passage connecting the outlet port and the second working chamber. cage,
Da is the minimum diameter of the first throttle passage, Db is the minimum diameter of the first connection passage, and the valve chamber when the outlet port and the first working chamber are connected by the first connection passage. A flow path switching valve, wherein the following formula (1) is satisfied, where ΔP is the pressure difference with respect to the first working chamber.
Rmin≦Da/Db (1)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27 The flow path switching valve according to claim 1, which satisfies the following formula (1A).
Rmin≦Da/Db≦Rmax (1A)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27
When 0.2 MPa ≤ ΔP < 1.0 MPa,
Rmax=(ΔP+(11.80))/11.43
When 1.0 MPa ≤ ΔP < 2.0 MPa,
Rmax=(ΔP+(12.97))/12.47
When 2.0 MPa ≤ ΔP < 3.0 MPa,
Rmax=(ΔP+(5.62))/6.35
When 3.0 MPa ≤ ΔP < 4.0 MPa,
Rmax=(ΔP+(2.48))/4.04
When 4.0 MPa ≤ ΔP < 5.0 MPa,
Rmax=(ΔP+(0.90))/3.05
When 5.0 MPa ≤ ΔP < 6.0 MPa,
Rmax = (ΔP + (-1.23)) / 1.95
When 6.0 MPa ≤ ΔP < 7.0 MPa,
Rmax = (ΔP + (-3.28)) / 1.11
When 7.0 MPa ≤ ΔP < 8.0 MPa,
Rmax = (ΔP + (-5.22)) / 0.53
When 8.0 MPa ≤ ΔP ≤ 10.0 MPa,
Rmax = (ΔP + (-5.99)) / 0.38 2. The flow path switching valve according to claim 1, which satisfies the following formula (1B).
Rmin≦Da/Db≦Rmax (1B)
however,
When 0.2 MPa ≤ ΔP ≤ 10.0 MPa,
Rmin=(ΔP+(21.65))/30.27
When 0.2 MPa ≤ ΔP < 1.0 MPa,
Rmax=(ΔP+(15.80))/16.00
When 1.0 MPa ≤ ΔP < 2.0 MPa,
Rmax=(ΔP+(14.41))/14.67
When 2.0 MPa ≤ ΔP < 3.0 MPa,
Rmax=(ΔP+(6.96))/8.01
When 3.0 MPa ≤ ΔP < 4.0 MPa,
Rmax=(ΔP+(3.56))/5.28
When 4.0 MPa ≤ ΔP < 5.0 MPa,
Rmax=(ΔP+(1.85))/4.08
When 5.0 MPa ≤ ΔP < 6.0 MPa,
Rmax = (ΔP + (-0.48)) / 2.69
When 6.0 MPa ≤ ΔP < 7.0 MPa,
Rmax = (ΔP + (-2.73)) / 1.60
When 7.0 MPa ≤ ΔP < 8.0 MPa,
Rmax = (ΔP + (-4.83)) / 0.81
When 8.0 MPa ≤ ΔP ≤ 10.0 MPa,
Rmax = (ΔP + (-5.50)) / 0.64 said first piston and said second piston each having a metal part;
A through hole formed in the metal part is a portion where the first throttle passage has a minimum diameter,
The flow path switching valve according to any one of claims 1 to 3, wherein a portion having the smallest diameter of the second throttle passage is a through hole formed in the metal part. The minimum diameter of the second throttle passage is the same as the minimum diameter Da of the first throttle passage,
the minimum diameter of the second connection passage is the same as the minimum diameter Db of the first connection passage;
Da is the minimum diameter of the second throttle passage, Db is the minimum diameter of the second connection passage, and the valve chamber when the outlet port and the second working chamber are connected by the second connection passage. 2. The flow path switching valve according to claim 1, wherein the above formula (1) is satisfied, where .DELTA.P is the pressure difference with respect to the second working chamber.

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