Flow passage switching valve, and refrigeration cycle device

Abstract

To reduce a pressure loss of a low-pressure refrigerant flowing through a flow passage switching valve.SOLUTION: A flow passage switching valve 18 comprises: a housing body 31 internally comprising a hollow part 31A; and a valve element 60 rotatably housed in the hollow part 31A, and to be switched between a first posture and a second posture by being rotated and operated. In the housing body 31, a first opening P1, a second opening P2, and a third opening P3 for establishing communication between the hollow part 31A and the outside of the housing body 31 are formed. In the valve element 60, a through hole 61 for connecting the first opening P1 and the second opening P2 in the first posture, and connecting the first opening P1 and the third opening P3 in the second posture, and through which a low-pressure refrigerant to be sucked by a compressor 15 of a refrigerant circuit flows, and a concave part 62 for communicating with the third opening P3 in the first posture, and communicating with the second opening P2 in the second posture, and having a shape formed by recessing an outer surface of the valve element 60 are formed.SELECTED DRAWING: Figure 9A

Description

[Technical field]

[0001] The present disclosure relates to a flow path switching valve and a refrigeration cycle device. [Background technology]

[0002] Patent Document 1 discloses an air conditioner that switches between cooling and heating. This air conditioner is equipped with a flow path switching valve that switches the refrigerant discharged from a compressor to flow either an outdoor heat exchanger or an indoor heat exchanger. The flow path switching valve of Patent Document 1 has a switching valve body that functions as a housing, and a valve body that is rotatably accommodated inside the switching valve body. The switching valve body is formed with a first connection port to which the discharge side piping of the compressor is connected, a second connection port to which the inlet side piping of the indoor heat exchanger is connected, a third connection port to which the outlet side piping of the indoor heat exchanger is connected, a fourth connection port to which the suction side piping of the compressor is connected, a fifth connection port to which the outlet side piping of the outdoor heat exchanger is connected, and a sixth connection port to which the inlet side piping of the outdoor heat exchanger is connected. The valve body is formed with a plurality of communication passages which, during cooling operation, connect the first connection port to the sixth connection port, and the third connection port to the fourth connection port, and also connect the second connection port to the fifth connection port via a throttling passage, and, during heating operation, connect the first connection port to the second connection port, and the fourth connection port to the fifth connection port, and also connect the third connection port to the sixth connection port via a throttling passage. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2011-202738 A Summary of the Invention [Problem to be solved by the invention]

[0004] The low-pressure refrigerant drawn into the compressor has a lower density than the high-pressure refrigerant discharged from the compressor. Therefore, the low-pressure refrigerant flowing through the flow path switching valve is more likely to experience pressure loss than the high-pressure refrigerant. The flow path switching valve described in Patent Document 1 does not take such pressure loss of the low-pressure refrigerant into consideration. The present disclosure aims to reduce the pressure loss of the low-pressure refrigerant flowing through the flow path switching valve. [Means for solving the problem]

[0005] (1) The flow path switching valve of the present disclosure is A container having a hollow space therein; a valve body that is rotatably accommodated in the hollow portion and that is switched between a first position and a second position by being rotated; a first opening, a second opening, and a third opening are formed in the container, the first opening, the ... The valve body, a through hole that connects the first opening and the second opening in the first position and connects the first opening and the third opening in the second position, and through which a low-pressure refrigerant sucked into a compressor of a refrigerant circuit flows; a recessed portion that communicates with the third opening in the first position and communicates with the second opening in the second position, the recessed portion having a recessed shape on an outer surface of the valve body; is formed.

[0006] According to the above-mentioned configuration, since the valve body is formed with the through holes and the recesses instead of with a plurality of through holes, the volume of the through holes in the entire valve body can be increased, and the cross-sectional area of ​​the refrigerant flow path formed by the through holes can be increased, thereby reducing the pressure loss of the low-pressure refrigerant flowing through the through holes.

[0007] (2) In the flow path switching valve of (1), a fourth opening is formed in the container, the fourth opening communicating the hollow portion with the outside of the container, The recess connects the third opening and the fourth opening in the first position, and connects the second opening and the fourth opening in the second position, through which high-pressure refrigerant discharged from the compressor flows.

[0008] According to the above configuration, the high-pressure refrigerant can be caused to flow by utilizing the recess, and the flow path switching valve can be used as a four-way switching valve.

[0009] (3) In the flow path switching valve of (1) or (2), the volume of the through hole is 28% or more and 69% or less of the volume of the valve body.

[0010] According to the above configuration, the cross-sectional area of ​​the through hole through which the low-pressure refrigerant flows can be increased, thereby reducing pressure loss.

[0011] (4) The flow path switching valve of (2) above includes a leakage portion that causes the high-pressure refrigerant flowing in from the fourth opening to leak into the hollow portion.

[0012] According to the above-described configuration, the pressure of the leaked high-pressure refrigerant can be applied approximately evenly to the entire outer surface of the valve body, and the load torque for rotating the valve body can be reduced.

[0013] (5) In the flow path switching valve described in any one of (1) to (4), in an outer surface of the valve body, one end of the through hole opens on a first axis that is a rotation axis of the valve body, and the other end of the through hole opens on a second axis that is perpendicular to the first axis, A recess is formed on the outer surface of the valve body in an area spanning a first position located on a third axis perpendicular to the first axis and the second axis, and a second position located on the opposite side of the third axis from the first position.

[0014] According to the above configuration, a flow path through which the low pressure refrigerant and the high pressure refrigerant flow can be formed by the through hole and the recess.

[0015] (6) In the flow path switching valve described in any one of (1) to (4), in an outer surface of the valve body, one end of the through hole opens on a first axis perpendicular to a rotation axis of the valve body, and the other end of the through hole opens on a second axis perpendicular to the rotation axis and the first axis, The recess is formed on the outer surface of the valve body over a range spanning a first position located on the opposite side of one end of the through hole on the first axis and a second position located on the opposite side of the other end of the through hole on the second axis.

[0016] According to the above configuration, a flow path through which the low pressure refrigerant and the high pressure refrigerant flow can be formed by the through hole and the recess.

[0017] (7) A refrigeration cycle device according to the present disclosure includes the flow path switching valve according to any one of (1) to (6) above. [Brief description of the drawings]

[0018] [Figure 1] 1 is a schematic diagram showing a refrigerant circuit of a refrigeration cycle device including a flow path switching valve according to a first embodiment of the present disclosure. [Figure 2A] FIG. [Figure 2B] FIG. [Diagram 3] FIG. 2 is a perspective view of a valve body of the flow path switching valve. [Figure 4] FIG. 2 is a front view of a valve body of the flow path switching valve. [Diagram 5] FIG. 4 is a side view of a valve body of the flow path switching valve. [Figure 6] FIG. 4 is a rear view of the valve body of the flow path switching valve. [Figure 7] 5 is a cross-sectional view taken along line AA in FIG. 4. [Figure 8] 5 is a cross-sectional view taken along line BB in FIG. 4. [Figure 9A] 5A and 5B are diagrams illustrating the operation of a flow path switching valve. [Figure 9B] 5A and 5B are diagrams illustrating the operation of a flow path switching valve. [Figure 10]5 is a schematic graph showing the relationship between the outer diameter of a valve body of a flow path switching valve and the cross-sectional area of ​​a flow path for a low-pressure refrigerant that can be formed in the valve body. [Figure 11] FIG. 11 is a perspective view of a flow path switching valve according to a second embodiment of the present disclosure. [Figure 12] FIG. 2 is a perspective view of a valve body of the flow path switching valve. [Figure 13] FIG. 2 is a perspective view of a valve body of the flow path switching valve. [Figure 14A] 5A and 5B are diagrams illustrating the operation of a flow path switching valve. [Figure 14B] 5A and 5B are diagrams illustrating the operation of a flow path switching valve. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. [First embodiment] FIG. 1 is a schematic diagram showing a refrigerant circuit of a refrigeration cycle device including a flow path switching valve according to a first embodiment of the present disclosure. The refrigeration cycle apparatus 10 includes a refrigerant circuit 30 that performs a vapor compression refrigeration cycle operation. The refrigeration cycle apparatus 10 of this embodiment is an air conditioner. As shown in FIG. 1, the air conditioner 10 has an outdoor unit (heat source unit) 11 and an indoor unit (utilization unit) 12. The outdoor unit 11 and the indoor unit 12 are connected by connecting pipes 13 and 14, respectively. The outdoor unit 11, the indoor unit 12, and the connecting pipes 13 and 14 form a refrigerant circuit 30. Note that the refrigeration cycle apparatus 10 is not limited to an air conditioner, and may be a refrigerator, a freezer, a water heater, or the like.

[0020] (Refrigerant circuit configuration) 1, the outdoor unit 11 is provided with a compressor 15, an outdoor heat exchanger (heat source heat exchanger; second heat exchanger) 16, an expansion valve 17, and a four-way switching valve (flow path switching valve) 18, which constitute a refrigerant circuit 30. The outdoor unit 11 is also provided with an outdoor fan 19. The indoor unit 12 is provided with an indoor heat exchanger (utilization heat exchanger; first heat exchanger) 21, which constitutes the refrigerant circuit 30. The indoor unit 12 is also provided with an indoor fan 22.

[0021] The compressor 15 is a positive displacement compressor, such as a scroll type or rotary type compressor, and has a built-in compressor motor. The compressor 15 compresses the low-pressure refrigerant sucked in through a suction pipe 52, and then discharges the refrigerant from a discharge pipe 51. In the outdoor unit 11, the discharge side of the compressor 15 is connected to a fourth port (fourth opening) P4 of the four-way switching valve 18 through the discharge pipe 51. The suction side of the compressor 15 is connected to a first port P1 of the four-way switching valve 18 through the suction pipe 52.

[0022] The outdoor heat exchanger 16 is configured by a cross-fin type fin-and-tube heat exchanger, a microchannel type heat exchanger, etc. The gas side end of the outdoor heat exchanger 16 is connected to a third port P3 of the four-way switching valve 18 via a refrigerant pipe 53. The liquid side end of the outdoor heat exchanger 16 is connected to one end of the expansion valve 17 via a refrigerant pipe 54.

[0023] The expansion valve 17 is, for example, an electrically operated valve whose opening degree is adjustable. The other end of the expansion valve 17 is connected to the liquid side stop valve 23 via a refrigerant pipe 55.

[0024] The indoor heat exchanger 21 is configured by a cross-fin type fin-and-tube heat exchanger or a microchannel type heat exchanger, etc. The liquid side end of the indoor heat exchanger 21 is connected to a liquid side shutoff valve 23 via a liquid side connecting pipe 14. The gas side end of the indoor heat exchanger 21 is connected to a gas side shutoff valve 24 via a gas side connecting pipe 13. The gas side shutoff valve 24 is connected to a second port P2 of the four-way switching valve 18 via a refrigerant piping 56.

[0025] The four-way switching valve 18 switches the flow path between a first state (shown by solid lines in FIG. 1) in which the first port P1 and the second port P2 communicate with each other and the third port P3 and the fourth port P4 communicate with each other, and a second state (shown by dotted lines in FIG. 1) in which the first port P1 and the third port P3 communicate with each other and the second port P2 and the fourth port P4 communicate with each other. In the first state, the refrigerant discharged from the compressor 15 flows to the outdoor heat exchanger 16, and in the second state, the refrigerant discharged from the compressor 15 flows to the indoor heat exchanger 21.

[0026] The outdoor fan 19 is disposed near the outdoor heat exchanger 16. The outdoor fan 19 is rotationally driven by a motor to send air to the outdoor heat exchanger 16. The refrigerant flowing through the outdoor heat exchanger 16 exchanges heat with the outdoor air sent by the outdoor fan 19, and evaporates or condenses.

[0027] The indoor fan 22 is disposed near the indoor heat exchanger 21. The indoor fan 22 is rotationally driven by a motor to send air to the indoor heat exchanger 21. The refrigerant flowing through the indoor heat exchanger 21 exchanges heat with the indoor air sent by the indoor fan 22, and condenses or evaporates.

[0028] The air conditioner 10 switches the four-way switching valve 18 to the first mode when performing cooling operation, and switches the four-way switching valve 18 to the second mode when performing heating operation. In cooling operation, the gas refrigerant discharged from the compressor 15 flows through the four-way switching valve 18 into the outdoor heat exchanger 16 functioning as a condenser, and is condensed into liquid refrigerant. This liquid refrigerant is decompressed in the expansion valve 17 to become a two-phase gas-liquid refrigerant, and flows into the indoor heat exchanger 21 functioning as an evaporator. The two-phase gas-liquid refrigerant exchanges heat with air sent by the indoor fan 22 and evaporates to become a gas refrigerant. The air cooled by the heat exchange is supplied to the room. The gas refrigerant flowing out of the indoor heat exchanger 21 is sucked into the compressor 15 through the four-way switching valve 18.

[0029] In heating operation, the gas refrigerant discharged from the compressor 15 flows through the four-way switching valve 18 into the indoor heat exchanger 21 functioning as a condenser. The gas refrigerant exchanges heat with air sent by the indoor fan 22 and condenses to become liquid refrigerant. The air heated by the heat exchange is supplied to the room. The liquid refrigerant flowing out from the indoor heat exchanger 21 is decompressed in the expansion valve 17 to become a two-phase gas-liquid refrigerant, and flows into the outdoor heat exchanger 16 functioning as an evaporator. The two-phase gas-liquid refrigerant evaporates in the outdoor heat exchanger 16 to become gas refrigerant. The gas refrigerant is sucked into the compressor 15 through the four-way switching valve 18.

[0030] (Configuration of flow path switching valve) 2A and 2B are perspective and cross-sectional views of the flow path switching valve. The four-way switching valve 18 , which is a flow path switching valve, has a casing 31 . The casing 31 constitutes the outer shell of the four-way switching valve 18, and accommodates the valve body 60 therein. The casing 31 is formed in a substantially rectangular parallelepiped shape. The casing 31 has four side surfaces 31a, 31b, 31c, and 31d, an upper surface 31e, and a lower surface 31f. The casing 31 has a hollow portion 31A therein. The hollow portion 31A is formed in a substantially rectangular parallelepiped shape.

[0031] The casing 31 is formed, for example, from a material containing aluminum as a main component, such as an aluminum alloy or pure aluminum. The casing 31 is formed, for example, by casting, such as aluminum die casting. The material of the casing 31 is not limited to the above, and may be other materials, such as stainless steel, iron, copper, etc. The manufacturing method of the casing 31 is also not particularly limited.

[0032] The casing 31 has ports P1 to P4 formed in the top surface 31e and the three side surfaces 31a, 31b, and 31c. Specifically, the casing 31 has a first port P1 formed in the top surface 31e. The casing 31 has a fourth port P4 formed in one side surface 31a. Of the other two side surfaces 31b and 31c adjacent to both sides of the side surface 31a, the side surface 31b has a second port P2 formed therein, and the other side surface 31c has a third port P3 formed therein. The first to fourth ports P1 to P4 are holes (flow paths) that penetrate the casing 31 between the top surface 31e and the sides 31a to 31c and the hollow portion 31A. The first to fourth ports P1 to P4 correspond to the first to fourth ports P1 to P4 described with reference to FIG. 1.

[0033] The four-way switching valve 18 has a valve body 60. The valve body 60 is disposed in the hollow portion 31A of the casing 31. The valve body 60 is formed in a spherical shape. As shown in FIG. 2B, a packing 36 is provided between each of the ports P1 to P4 of the casing 31 and the valve body 60. The packing 36 is formed in an annular shape. The packing 36 contacts the outer surface (spherical surface) of the valve body 60.

[0034] The packing 36 is made of a material having a smaller elastic modulus than the casing 31. The packing 36 is an elastic member made of a synthetic resin such as PEEK (polyether ether ketone) or PTFE (polytetrafluoroethylene). Therefore, the packing 36 elastically contacts the outer surface of the valve body 60. The packing 36 has a function of suppressing leakage of the refrigerant from the refrigerant flow path and a function of supporting the valve body 60 within the hollow portion 31A.

[0035] As shown in FIG. 2A, the valve body 60 rotates around a predetermined rotation axis C. The rotation axis C of the valve body 60 passes through the center P of the spherical shape of the valve body 60. A drive shaft 66 is disposed on the rotation axis C. The drive shaft 66 is provided in the lower part of the casing 31. The drive shaft 66 has an axis in the vertical direction. The drive shaft 66 penetrates the casing 31 between the lower surface 31f of the casing 31 and the hollow part 31A. In the hollow part 31A, an end of the drive shaft 66 is fixed to the valve body 60. Outside the casing 31, a drive unit 64 and a reduction unit 65 are connected to the drive shaft 66.

[0036] The driving unit 64 is an electric motor. The driving unit 64 generates and outputs a rotational power. The speed reducing unit 65 reduces the speed of the rotational power output from the driving unit 64 and transmits it to the driving shaft 66. The speed reducing unit 65 includes a reduction gear that reduces the speed of the rotational power of the driving unit 64. The driving unit 64, the speed reducing unit 65, and the driving shaft 66 constitute a driving device that drives the valve body 60. The speed reducing unit 65 reduces the speed of the rotational power of the driving unit 64 and transmits it to the driving shaft 66 and the valve body 60, thereby increasing the output torque to the valve body 60. Therefore, the output of the driving unit 64 for rotating the valve body 60 can be reduced, and the driving unit 64 can be made smaller in size.

[0037] (Specific structure of the valve body) FIG. 3 is a perspective view of the valve body of the flow path switching valve. FIG. 4 is a front view of the valve body of the flow path switching valve. FIG. 5 is a side view of the valve body of the flow path switching valve. FIG. 6 is a rear view of the valve body of the flow path switching valve. FIG. 7 is a cross-sectional view taken along line AA in FIG. 4. FIG. 8 is a cross-sectional view taken along line BB in FIG. 4. Each drawing shows a first axis C1 coinciding with the rotation axis C of the valve body 60, a second axis C2 perpendicular to the first axis C1, and a third axis C3 perpendicular to the first axis C1 and the second axis C2. The first to third axes C1 to C3 intersect at the center P of the spherical shape of the valve body 60.

[0038] The valve body 60 is formed with a through hole 61 and a recess 62. The through hole 61 and the recess 62 both form a flow path for the refrigerant. The through hole 61 is a hole that penetrates the valve body 60. In contrast, the recess 62 is formed in a shape in which the outer surface of the valve body 60 is recessed.

[0039] The through hole 61 is open at two places on the outer surface of the valve body 60. One opening 61a of the through hole 61 is formed on the first axis C1. Specifically, one opening 61a is formed on the outer surface of the valve body 60 on the first axis C1 opposite to the drive shaft 66. The other opening 61b is formed on the second axis C2. Therefore, as shown in FIG. 7, the through hole 61 has a shape bent into a substantially L-shape. The areas of both openings 61a and 61b are the same. The cross-sectional area of ​​the through hole 61 (area of ​​a cross section perpendicular to the center line of the through hole 61; cross-sectional area) is substantially the same as the areas of the openings 61a and 61b. Specifically, the cross-sectional area of ​​the through hole 61 is the same as the areas of the openings 61a and 61b, or is slightly larger or smaller than the areas of the openings 61a and 61b.

[0040] 6 and 8, the recess 62 is formed in the outer surface of the valve body 60 in a range (a range of 180° around the first axis C1) spanning from a first position G1 located on the third axis C3 to a second position G2 located on the opposite side of the first position G1 on the third axis C3. The recess 62 has a width w (see FIG. 6) in the direction along the first axis C1 that is slightly smaller than the diameter of the openings 61a, 61b of the through hole 61.

[0041] The bottom surface of the recess 62 in this embodiment is composed of a plurality of planes H1, H2, and H3. Specifically, the bottom surface of the recess 62 is composed of two first planes H1 located on the third axis C3, one second plane H2 located on the second axis C2, and two third planes H3 located between the first plane H1 and the second plane H2. The first plane H1 is approximately perpendicular to the third axis C3. The second plane H2 is approximately perpendicular to the second axis C2. The third plane H3 is inclined with respect to the second and third axes C2 and C3. The bottom surface of the recess 62 may be formed by a plurality of planes, four or less, or six or more. The bottom surface of the recess 62 may not be formed by a plurality of planes, and may be a curved surface curved around the first axis C1.

[0042] Valve body 60 is not a perfect sphere but has a part of its spherical surface missing due to the formation of through hole 61 and recess 62. In Figures 4 to 8, the shape of a perfect sphere without missing parts is shown by imaginary line L.

[0043] As shown in Fig. 2B, one opening 61a of the through hole 61 always communicates with the first port P1. The other opening 61b of the through hole 61 selectively communicates with one of the second port P2 and the third port P3 by the valve body 60 rotating 180° around the first axis C1. Therefore, the through hole 61 forms a refrigerant flow path from the second port P2 to the first port P1 as shown by the solid arrow in Fig. 1, and a refrigerant flow path from the third port P3 to the first port P1 as shown by the dotted arrow in Fig. 1. These refrigerant flow paths are flow paths through which the "low-pressure refrigerant" sucked into the compressor 15 flows.

[0044] 2B, the packing 36 provided between the first, second, and third ports P1, P2, and P3 and the valve body 60 is in close contact with the outer surface of the valve body 60 around the entire circumference of each opening 61a, 61b of the through hole 61. Therefore, the packing 36 suppresses leakage of the low-pressure refrigerant flowing between the first, second, and third ports P1, P2, and P3 and the through hole 61 of the valve body 60 into the hollow portion 31A.

[0045] The recess 62 formed in the valve body 60 always communicates with the fourth port P4. The recess 62 selectively communicates with one of the second port P2 and the third port P3 by the valve body 60 rotating 180° around the first axis C1. Therefore, the recess 62 forms a refrigerant flow path from the fourth port P4 to the third port P3 as shown by the solid arrow in Fig. 1, and a refrigerant flow path from the fourth port P4 to the second port P2 as shown by the dotted arrow in Fig. 1. These refrigerant flow paths are flow paths through which the "high-pressure refrigerant" discharged from the compressor 15 flows.

[0046] As shown in FIG. 2B, the packing 36 provided between the second, third, and fourth ports P2, P3, and P4 and the valve body 60 is in close contact with the outer surface of the valve body 60 around the recess 62. However, since the recess 62 is continuously formed on the outer surface of the valve body 60 between the fourth port P4 and the second port P2 or the third port P3, the packing 36 cannot contact the entire periphery of the recess 62. Therefore, a gap S is generated between the packing 36 and the outer surface of the valve body 60. When the high-pressure refrigerant enters the recess 62 from the fourth port P4, it leaks from the gap S into the hollow portion 31A before reaching the second port P2 or the third port P3. When the high-pressure refrigerant leaks into the hollow portion 31A in this way, the pressure of the high-pressure refrigerant is uniformly applied to the entire outer surface of the valve body 60 in the hollow portion 31A. Therefore, it is possible to prevent the load torque for rotating the valve body 60 from becoming excessive, which would be caused by the outer surface of the valve body 60 coming into strong local contact with some of the packings 36. This allows the drive unit 64 to have a small output.

[0047] (Switching of flow path by valve body 60) 9A and 9B are diagrams for explaining the operation of the flow path switching valve. The valve body 60 is switched between a first position (see FIG. 9A) and a second position (see FIG. 9B) by rotating 180 degrees about the first axis C1. In the first position shown in Fig. 9A, the first port P1 and the second port P2 are connected by the through hole 61 of the valve body 60, and the fourth port P4 and the third port P3 are connected by the recess 62. Therefore, as shown by the solid arrow in Fig. 1, the refrigerant discharged from the compressor 15 flows into the four-way switching valve 18 from the fourth port P4, flows out of the four-way switching valve 18 from the third port P3, and is supplied to the outdoor heat exchanger 16. The refrigerant flowing out of the indoor heat exchanger 21 flows into the four-way switching valve 18 from the second port P2, flows out of the four-way switching valve 18 from the first port P1, and is sucked into the compressor 15. This enables the air conditioner 10 to perform cooling operation.

[0048] In the second position shown in Fig. 9B, the first port P1 and the third port P3 are connected by the through hole 61 of the valve body 60, and the fourth port P4 and the second port P2 are connected by the recess 62. Therefore, as shown by the dotted arrow in Fig. 1, the refrigerant discharged from the compressor 15 flows into the four-way switching valve 18 from the fourth port P4, flows out of the four-way switching valve 18 from the second port P2, and is supplied to the indoor heat exchanger 21. The refrigerant flowing out of the outdoor heat exchanger 16 flows into the four-way switching valve 18 from the third port P3, flows out of the four-way switching valve 18 from the first port P1, and is sucked into the compressor 15. This enables the air conditioner 10 to perform a heating operation.

[0049] In a refrigeration system, the high-pressure refrigerant discharged from the compressor 15 and the low-pressure refrigerant drawn into the compressor 15 have different densities. Specifically, the low-pressure refrigerant has a lower density than the high-pressure refrigerant. Therefore, the low-pressure refrigerant is more likely to experience pressure loss while flowing through the refrigerant flow path than the high-pressure refrigerant. In order to suppress such pressure loss, it is desirable to increase the cross-sectional area (the area of ​​a cross section perpendicular to the flow of the refrigerant; transverse area) of the refrigerant flow path through which the low-pressure refrigerant flows.

[0050] As described in Patent Document 1, when a valve body has a plurality of through holes, the cross-sectional area of ​​the through hole through which the low-pressure refrigerant flows cannot be increased significantly due to the presence of other through holes. In contrast, the valve body 60 of this embodiment has a through hole 61 and a recess 62, and the through hole 61 serves as a flow path for the low-pressure refrigerant, and the recess 62 serves as a flow path for the high-pressure refrigerant. The recess 62 is formed by recessing the outer surface of the valve body 60 and is open to the outside, so that the recess 62 can be formed at a position closer to the outer surface of the valve body 60. Therefore, the remaining part of the valve body 60 other than the recess 62 can be made larger, and the remaining part can be used to form the through hole (flow path for the low-pressure refrigerant) 61 with a larger cross-sectional area.

[0051] In order to increase the cross-sectional area of ​​the through hole 61 in the valve element 60, it is also possible to increase the outer diameter of the valve element 60 itself. However, adopting such a measure leads to an increase in the size of the four-way switching valve 18. Furthermore, adopting such a measure increases the contact area of ​​the packing 36 with the valve element 60, so that the load torque for rotating the valve element 60 increases due to frictional resistance, and thus a higher output from the drive unit 64 is required.

[0052] FIG. 10 is a schematic graph showing the relationship between the outer diameter of the valve body of the flow path switching valve and the cross-sectional area of ​​the flow path of the low-pressure refrigerant that can be formed in the valve body. The solid line in FIG. 10 shows the graph of this embodiment in which a through hole 61 and a recess 62 are formed in the valve body 60 as the refrigerant flow path, and the dotted line in FIG. 10 shows the graph of the conventional technology (for example, Patent Document 1) in which two through holes are formed in the valve body as the refrigerant flow path. In FIG. 10, when the cross-sectional area of ​​the flow path of the low-pressure refrigerant is set to value A, in the conventional technology, the outer diameter of the valve body needs to be a2, but in this embodiment, the outer diameter of the valve body 60 can be a1, which is smaller than a2. In other words, in this embodiment, the valve body 60 with a smaller outer diameter can be used to form the through hole 61 with a larger cross-sectional area compared to the conventional technology. Therefore, the four-way switching valve 18 of this embodiment can contribute to reducing the pressure loss of the low-pressure refrigerant, reducing the size of the four-way switching valve 18, and reducing the output of the drive unit 64.

[0053] In this embodiment, the volume of the through hole 61 in the valve body 60 can be 28% or more and 69% or less of the volume of the valve body 60. In other words, by adopting the configuration of this embodiment, the volume of the through hole 61 can be increased to a maximum of 69% of the volume of the valve body 60. The volume of the through hole 61 is preferably 50% or more, more preferably 60% or more of the volume of the valve body 60. In this specification, the volume of the through hole 61 is the volume of the space surrounded by the cylindrical surface (inner peripheral surface) of the valve body 60 that forms the through hole 61. The volume of the recess 62 is the volume of the space surrounded by the bottom surface and side surface that form the recess 62. The volume of the valve body 60 is the substantial volume of the valve body 60 excluding the volume of the through hole 61 and the volume of the recess 62.

[0054] [Second embodiment] Fig. 11 is a perspective view of a flow path switching valve according to a second embodiment of the present disclosure. Fig. 12 is a perspective view of a valve body of the flow path switching valve. Fig. 13 is a perspective view of the valve body of the flow path switching valve. Figs. 12 and 13 show a rotation axis C of the valve body 60, a first axis C1 perpendicular to the rotation axis C, and a second axis C2 perpendicular to the rotation axis C and the first axis C1. The rotation axis C and the first and second axes C1 and C2 intersect at the center P of the spherical shape of the valve body 60.

[0055] In the flow path switching valve 18 of the present embodiment, the first port P1 is not formed on the top surface 31e of the casing 31, but is formed on the side surface 31d of the casing 31. Therefore, in the present embodiment, the first to fourth ports P1 to P4 are all formed on the side surfaces 31a to 31d of the casing 31.

[0056] Similar to the first embodiment, the valve body 60 of this embodiment is formed with a through hole 61 and a recess 62. The through hole 61 and the recess 62 both form a flow path for the refrigerant. The through hole 61 is a hole that penetrates the valve body 60. In contrast, the recess 62 is formed in a shape in which the outer surface of the valve body 60 is recessed.

[0057] The through hole 61 is open at two places on the outer surface of the valve body 60. One opening 61a of the through hole 61 is formed on the first axis C1. The other opening 61b is formed on the second axis C2. Therefore, as shown in Fig. 13, the through hole 61 is bent in a substantially L-shape.

[0058] The recess 62 is formed on the outer surface of the valve body 60 over a range (a range of 90° around the rotation axis C) spanning between a first position G1 located on the opposite side of one opening 61a of the through hole 61 on the first axis C1 and a second position G2 located on the opposite side of the other opening 61b of the through hole 61 on the second axis C2.

[0059] The bottom surface of the recess 62 in this embodiment is composed of a plurality of planes H1 and H2. Specifically, the bottom surface of the recess 62 is composed of two first planes H1 located on the first and second axes C1 and C2, and a second plane H2 located between the two first planes H1. Of the two first planes H1, one first plane H1 is approximately perpendicular to the first axis C1, and the other first plane H1 is approximately perpendicular to the second axis C2. The two first planes H1 are in a relationship of approximately perpendicular to each other. The second plane H2 is inclined with respect to the first and second axes C1 and C2. The bottom surface of the recess 62 may be formed by a plurality of planes, four or more. The bottom surface of the recess 62 may not be formed by a plurality of planes, and may be a curved surface that curves around the first axis C1.

[0060] Valve body 60 is not a perfect sphere, but a sphere with a part of the spherical surface missing, due to the formation of through hole 61 and recess 62. In Fig. 13, the shape of a perfect sphere without a missing part is shown by imaginary line L.

[0061] (Switching of flow path by valve body 60) 14A and 14B are diagrams for explaining the operation of the flow path switching valve. In this embodiment, the valve body 60 is switched between a first position (see FIG. 14A) and a second position (see FIG. 14B) by rotating 90 degrees about the rotation axis C. In the first position shown in FIG. 14A, the first port (first opening) P1 and the second port (second opening) P2 are connected by the through hole 61 of the valve body 60, and the fourth port (fourth opening) P4 and the third port (third opening) P3 are connected by the recess 62. Therefore, as shown by the solid arrow in FIG. 1, the refrigerant discharged from the compressor 15 flows into the four-way switching valve 18 from the fourth port P4, flows out of the four-way switching valve 18 from the third port P3, and is supplied to the outdoor heat exchanger 16. The refrigerant flowing out of the indoor heat exchanger 21 flows into the four-way switching valve 18 from the second port P2, flows out of the four-way switching valve 18 from the first port P1, and is sucked into the compressor 15. This enables the air conditioner 10 to perform cooling operation.

[0062] In the second position shown in Fig. 14B, the first port P1 and the third port P3 are connected by the through hole 61 of the valve body 60, and the fourth port P4 and the second port P2 are connected by the recess 62. Therefore, as shown by the dotted arrow in Fig. 1, the refrigerant discharged from the compressor 15 flows into the four-way switching valve 18 from the fourth port P4, flows out of the four-way switching valve 18 from the second port P2, and is supplied to the indoor heat exchanger 21. The refrigerant flowing out of the outdoor heat exchanger 16 flows into the four-way switching valve 18 from the third port P3, flows out of the four-way switching valve 18 from the first port P1, and is sucked into the compressor 15. This enables the air conditioner 10 to perform a heating operation.

[0063] Also in this embodiment, the refrigerant that flows into the recess 62 from the fourth port P4 leaks into the hollow portion 31A from the gap (leakage portion) S between the packing 36 and the valve body 60. Therefore, the pressure of the high-pressure refrigerant is applied uniformly to the entire outer surface of the valve body 60, and the load torque for rotating the valve body 60 can be reduced.

[0064] In this embodiment, the first to fourth ports P1 to P4 are all formed on the side surfaces 31a to 31d of the casing 31, so that the four-way switching valve 18 can be made smaller in size in the direction of the rotation axis C than in the first embodiment.

[0065] [Other embodiments] In the above embodiment, the high-pressure refrigerant flowing through the fourth port P4 and the second or third port P2, P3, which are in communication with each other through the recess 62, is configured to leak into the hollow portion 31A of the casing 31. However, the present invention is not limited to this, and the high-pressure refrigerant may be configured not to leak into the hollow portion 31A.

[0066] In the above embodiment, the rotation axis C of the valve body 60 is arranged to face in the vertical direction, but it may face in a direction other than the vertical direction, for example, the horizontal direction, or a direction inclined relative to the vertical and horizontal directions.

[0067] In the above embodiment, the casing 31 of the flow path switching valve 18 is formed in a substantially rectangular parallelepiped shape, but it may be formed in a cubic shape, a cylindrical shape, etc. The hollow portion 31A of the casing 31 may also be formed in a cubic shape, a cylindrical shape, etc.

[0068] In the above embodiment, the flow path switching valve 18 is a four-way switching valve, but it may be a three-way switching valve. In this case, for example, the fourth port of the above embodiment can be omitted. The second port P2 or the third port P3 of the flow path switching valve 18 may be closed. In this case, the flow path switching valve 18 also functions substantially as a three-way switching valve.

[0069] [Effects of the embodiment] (1) A flow path switching valve 18 of the present disclosure includes a container (casing) 31 having a hollow portion 31A therein, and a valve element 60 that is rotatably contained in the hollow portion 31A and can be switched between a first position and a second position by being rotated. A first opening (first port) P1, a second opening (second port) P2, and a third opening (third port) P3 that communicate between the hollow portion 31A and the outside of the container 31 are formed in the container 31. The valve body 60 is provided with a through hole 61 that connects the first opening P1 and the second opening P2 in the first position and connects the first opening P1 and the third opening P3 in the second position, through which the low-pressure refrigerant sucked into the compressor 15 of the refrigerant circuit 30 flows, and a recess 62 that communicates with the third opening P3 in the first position and communicates with the second opening P2 in the second position and has a shape in which the outer surface of the valve body 60 is recessed. In this manner, the valve body 60 of the present embodiment is provided with the through hole 61 and the recess 62, rather than a plurality of through holes. Therefore, the volume of the through hole 61 in the entire valve body 60 can be made larger, and the cross-sectional area of ​​the through hole 61 can be made larger. This can reduce the pressure loss of the low-pressure refrigerant flowing through the through hole 61.

[0070] (2) In the flow path switching valve of the above embodiment, the accommodating body 31 is formed with a fourth opening (fourth port) P4 that communicates between the hollow portion 31A and the outside of the accommodating body 31. The recess 62 connects the third opening P3 and the fourth opening P4 in the first position, and connects the second opening P2 and the fourth opening P4 in the second position, through which the high-pressure refrigerant discharged from the compressor 15 flows. Therefore, the high-pressure refrigerant can be caused to flow by utilizing the recess 62, and the flow path switching valve 18 can be used as a four-way switching valve.

[0071] (3) In the flow path switching valve 18 of the above embodiment, the volume of the through hole 61 is 28% to 69% of the volume of the valve body 60. In this embodiment, the outer surface of the valve body 60 is formed with the recess 62 through which the high-pressure refrigerant flows, so that the volume of the through hole 61 through which the low-pressure refrigerant flows can be increased to 69% of the volume of the valve body 60. As a result, the cross-sectional area of ​​the flow path for the low-pressure refrigerant by the through hole 61 is increased, and pressure loss can be suppressed.

[0072] (4) The flow path switching valve 18 of the first embodiment has the leakage portion (gap) S that allows the high-pressure refrigerant flowing in from the fourth opening P4 to leak into the hollow portion 31A. Therefore, the pressure of the leaked high-pressure refrigerant can be applied approximately evenly to the entire outer surface of the valve body 60, and the load torque for rotating the valve body 60 can be reduced.

[0073] (5) In the flow path switching valve 18 of the first embodiment, as shown in Fig. 3 to Fig. 7, on the outer surface of the valve body 60, one end of the through hole 61 opens on the first axis C1, which is the rotation axis C of the valve body 60, and the other end of the through hole 61 opens on the second axis C2 perpendicular to the first axis C1. On the outer surface of the valve body 60, a recess 62 is formed in a range extending from a first position G1 arranged on a third axis C3 perpendicular to the first axis C1 and the second axis C2 to a second position G2 arranged on the opposite side of the third axis C3 with respect to the first position G1. With this configuration, the through hole 61 through which the low-pressure refrigerant flows and the recess 62 through which the high-pressure refrigerant flows can be appropriately formed in the valve body 60.

[0074] (6) In the flow path switching valve 18 of the second embodiment, as shown in Fig. 12 and Fig. 13, on the outer surface of the valve body 60, one end of the through hole 61 opens on a first axis C1 perpendicular to the rotation axis C of the valve body 60, and the other end of the through hole 61 opens on a second axis C2 perpendicular to the rotation axis C and the first axis C1. On the outer surface of the valve body 60, a recess 62 is formed in a range extending from a first position G1 arranged on the opposite side of the first axis C1 to one end of the through hole 61, to a second position G2 arranged on the opposite side of the second axis C2 to the other end of the through hole 61. With this configuration, the through hole 61 through which the low-pressure refrigerant flows and the recess 62 through which the high-pressure refrigerant flows can be appropriately formed in the valve body 60.

[0075] Although the embodiments have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. [Explanation of symbols]

[0076] 10: Refrigeration cycle equipment 15: Compressor 18: Four-way switching valve (flow path switching valve) 30: Refrigerant circuit 31: Casing 31A: Hollow part 60: Valve body 61: Through hole 62: Recess C:Rotation axis center C1: 1st axis center C2: 2nd axis C3: 3rd axis G1: 1st position G2: 2nd position P1: First port (first opening) P2: Second port (second opening) P3: Third port (third opening) P4: 4th port (4th opening) S: Gap (leakage area)

Claims

1. A container (31) having a hollow portion (31A) therein; a valve body (60) that is rotatably accommodated in the hollow portion (31A) and that is switched between a first position and a second position by being rotated; A first opening (P1), a second opening (P2), and a third opening (P3) are formed in the container (31) to communicate the hollow portion (31A) with the outside of the container (31), The valve body (60), a through hole (61) that connects the first opening (P1) and the second opening (P2) in the first position and connects the first opening (P1) and the third opening (P3) in the second position, and through which a low-pressure refrigerant sucked into a compressor (15) of a refrigerant circuit (30) flows; a recess (62) that communicates with the third opening (P3) in the first position and communicates with the second opening (P2) in the second position, and that has a shape in which an outer surface of the valve body (60) is recessed; A flow path switching valve is formed.

2. A fourth opening (P4) is formed in the container (31) to communicate the hollow portion (31A) with the outside of the container (31), 2. The flow path switching valve according to claim 1, wherein the recess (62) connects the third opening (P3) and the fourth opening (P4) in the first position, and connects the second opening (P2) and the fourth opening (P4) in the second position, through which high-pressure refrigerant discharged from the compressor (15) flows.

3. 3. The flow path switching valve according to claim 1, wherein a volume of the through hole (61) is 28% or more and 69% or less of a volume of the valve body (60).

4. The flow path switching valve according to claim 2 , further comprising a leakage portion (S) that causes the high-pressure refrigerant flowing in from the fourth opening (P4) to leak into the hollow portion (31A).

5. On an outer surface of the valve body (60), one end of the through hole (61) opens on a first axis (C1) that is a rotation axis (C) of the valve body (60), and the other end of the through hole (61) opens on a second axis (C2) perpendicular to the first axis (C1); 3. The flow path switching valve according to claim 1, wherein a recess (62) is formed on an outer surface of the valve body (60) in a range spanning a first position (G1) located on a third axis (C3) perpendicular to the first axis (C1) and the second axis (C2), and a second position (G2) located on the opposite side of the third axis (C3) from the first position (G1).

6. On an outer surface of the valve body (60), one end of the through hole (61) opens on a first axis (C1) perpendicular to a rotation axis (C) of the valve body (60), and the other end of the through hole (61) opens on a second axis (C2) perpendicular to the rotation axis (C) and the first axis (C); 3. The flow path switching valve according to claim 1, wherein the recess (62) is formed on an outer surface of the valve body (60) in a range spanning a first position (G1) that is positioned on the opposite side of one end of the through hole (61) on the first axis (C1) and a second position (G2) that is positioned on the opposite side of the other end of the through hole (61) on the second axis (C2).

7. A refrigeration cycle device comprising the flow path switching valve (18) according to claim 1 or 2.

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