Flow path switching valve and refrigeration cycle device

Abstract

A flow path switching valve (18) is provided with: an accommodation body (31) having a hollow part (31A) therein; and a valve body 60 that is rotatably accommodated in the hollow part (31A) and is switched between a first posture and a second posture by being rotationally operated. In the accommodation body (31) are formed a first opening (P1), a second opening (P2), and a third opening (P3) that communicate the hollow part (31A) and the outside of the accommodation body (31). In the valve body (60) are formed: a through-hole (61) that connects the first opening (P1) and the second opening (P2) in the first posture, connects the first opening (P1) and the third opening (P3) in the second posture, and through which a low-pressure refrigerant sucked into a compressor (15) of a refrigerant circuit flows; and a recessed portion (62) that communicates with the third opening (P3) in the first posture, communicates with the second opening (P2) in the second posture, and has a shape in which the outer surface of the valve body (60) is recessed.

Description

Flow path switching valve and refrigeration cycle device

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

[0002] Patent Document 1 discloses an air conditioner that switches between cooling and heating modes. The air conditioner includes a flow path switching valve that switches the refrigerant discharged from a compressor between an outdoor heat exchanger and an indoor heat exchanger. The flow path switching valve in Patent Document 1 includes a switching valve body that functions as a housing and a valve element rotatably housed within the switching valve body. The switching valve body is formed with a first connection port connected to the discharge piping of the compressor, a second connection port connected to the inlet piping of the indoor heat exchanger, a third connection port connected to the outlet piping of the indoor heat exchanger, a fourth connection port connected to the suction piping of the compressor, a fifth connection port connected to the outlet piping of the outdoor heat exchanger, and a sixth connection port connected to the inlet piping of the outdoor heat exchanger. The valve body is formed with a plurality of communication passages which, during cooling operation, connect the first connection port with the sixth connection port, and the third connection port with the fourth connection port, and also connect the second connection port with the fifth connection port via a throttle passage, and, during heating operation, connect the first connection port with the second connection port, and the fourth connection port with the fifth connection port, and also connect the third connection port with the sixth connection port via a throttle passage.

[0003] JP 2011-202738 A

[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. An object of the present disclosure is to reduce the pressure loss of the low-pressure refrigerant flowing through the flow path switching valve.

[0005] (1) A flow path switching valve according to the present disclosure comprises: a housing having a hollow portion therein; and a valve body that is rotatably housed in the hollow portion and can be switched between a first position and a second position by being rotated; the housing has a first opening, a second opening, and a third opening that communicate the hollow portion with the outside of the housing; the valve body has 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, through which a low-pressure refrigerant sucked into a compressor of a refrigerant circuit flows; and a recess that communicates with the third opening in the first position and communicates with the second opening in the second position, and has a recessed shape on the outer surface of the valve body.

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

[0007] (2) In the flow path switching valve of (1), a fourth opening is formed in the housing, connecting the hollow portion with the outside of the housing, and 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 the 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 configuration, the pressure of the leaked high-pressure refrigerant can be applied substantially uniformly 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), on the outer surface of the valve body, one end of the through hole opens on a first axis which is the rotation axis of the valve body, and the other end of the through hole opens on a second axis which is perpendicular to the first axis, and on the outer surface of the valve body, a recess is formed in a range spanning from a first position located on a third axis which is perpendicular to the first axis and the second axis, to a second position located on the opposite side of the third axis from the first position.

[0014] According to the above configuration, the through-hole and the recessed portion can form a flow path through which the low-pressure refrigerant and the high-pressure refrigerant flow.

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

[0016] According to the above configuration, the through-hole and the recessed portion can form a flow path through which the low-pressure refrigerant and the high-pressure refrigerant flow.

[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.

[0018] 4 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. FIG. 4 is a perspective view of the flow path switching valve. FIG. 4 is a cross-sectional view of the flow path switching valve. FIG. 4 is a perspective view of a 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. 4 is a side view of the valve body of the flow path switching valve. FIG. 4 is a rear view of the valve body of the flow path switching valve. FIG. 4 is a cross-sectional view taken along line A-A in FIG. 4. FIG. 4 is a cross-sectional view taken along line B-B in FIG. 4. FIG. 4 is a diagram explaining the operation of the flow path switching valve. FIG. 4 is a diagram explaining the operation of the flow path switching valve. FIG. 4 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 ​​a flow path for low-pressure refrigerant that can be formed in the valve body. FIG. 4 is a perspective view of a flow path switching valve according to a second embodiment of the present disclosure. FIG. 4 is a perspective view of the valve body of the flow path switching valve. FIG. 4 is a perspective view of the valve body of the flow path switching valve. FIG. 4 is a diagram explaining the operation of the flow path switching valve.

[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 device 10 includes a refrigerant circuit 30 that performs a vapor compression refrigeration cycle operation. The refrigeration cycle device 10 of this embodiment is an air conditioner. As shown in FIG. 1, the air conditioner 10 includes 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 device 10 is not limited to an air conditioner and may be a refrigerator, a freezer, a water heater, or the like.

[0020] (Configuration of Refrigerant Circuit) As shown in Fig. 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, and includes a compressor motor. The compressor 15 compresses low-pressure refrigerant drawn in through a suction pipe 52 and then discharges the refrigerant through 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 as 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 shutoff valve 23 via a refrigerant pipe 55.

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

[0025] The four-way selector valve 18 switches the flow path between a first mode (shown by solid lines in FIG. 1 ) in which the first port P1 and the second port P2 are connected to each other and the third port P3 and the fourth port P4 are connected to each other, and a second mode (shown by dotted lines in FIG. 1 ) in which the first port P1 and the third port P3 are connected to each other and the second port P2 and the fourth port P4 are connected to each other. In the first mode, the refrigerant discharged from the compressor 15 flows to the outdoor heat exchanger 16, and in the second mode, 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 and sends 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 selector valve 18 to a first mode during cooling operation, and switches the four-way selector valve 18 to a second mode during heating operation. During cooling operation, gas refrigerant discharged from the compressor 15 passes through the four-way selector valve 18 and flows into the outdoor heat exchanger 16, which functions as a condenser, where it is condensed into liquid refrigerant. This liquid refrigerant is decompressed by the expansion valve 17 to become a two-phase gas-liquid refrigerant, which then flows into the indoor heat exchanger 21, which functions as an evaporator. The two-phase gas-liquid refrigerant exchanges heat with air sent by the indoor fan 22, evaporating and becoming gas refrigerant. The air cooled by this heat exchange is supplied indoors. The gas refrigerant flowing out of the indoor heat exchanger 21 passes through the four-way selector valve 18 and is drawn into the compressor 15.

[0029] During heating operation, gas refrigerant discharged from the compressor 15 passes through the four-way selector valve 18 and flows into the indoor heat exchanger 21, which functions as a condenser. The gas refrigerant exchanges heat with air sent by the indoor fan 22, condensing and becoming liquid refrigerant. The air heated by heat exchange is supplied indoors. The liquid refrigerant flowing out of the indoor heat exchanger 21 is decompressed by the expansion valve 17 and becomes two-phase gas-liquid refrigerant, and flows into the outdoor heat exchanger 16, which functions as an evaporator. The two-phase gas-liquid refrigerant evaporates in the outdoor heat exchanger 16 and becomes gas refrigerant. The gas refrigerant is drawn into the compressor 15 via the four-way selector valve 18.

[0030] (Configuration of flow path switching valve) Fig. 2A is a perspective view of the flow path switching valve. Fig. 2B is a cross-sectional view 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 forms the outer shell of the four-way switching valve 18 and houses a valve body 60 inside. 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 inside. 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] Ports P1 to P4 are formed on the top surface 31e and the three side surfaces 31a, 31b, and 31c of the casing 31, respectively. Specifically, a first port P1 is formed on the top surface 31e of the casing 31. A fourth port P4 is formed on one side surface 31a of the casing 31. Of the other two side surfaces 31b and 31c adjacent to the side surface 31a, a second port P2 is formed on the side surface 31b, and a third port P3 is formed on the other side surface 31c. The first to fourth ports P1 to P4 are holes (flow paths) that penetrate the casing 31 between the top surface 31e and the side surfaces 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 element 60. The valve element 60 is disposed in the hollow portion 31A of the casing 31. The valve element 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 element 60. The packing 36 is formed in an annular shape. The packing 36 contacts the outer surface (spherical surface) of the valve element 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 the function of suppressing leakage of the refrigerant from the refrigerant flow path and the 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 at the bottom 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 bottom surface 31f of the casing 31 and the hollow portion 31A. Within the hollow portion 31A, the end of the drive shaft 66 is fixed to the valve body 60. Outside the casing 31, a drive unit 64 and a speed reducer unit 65 are connected to the drive shaft 66.

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

[0037] (Specific Structure of Valve Disk) Fig. 3 is a perspective view of the valve disk of the flow path switching valve. Fig. 4 is a front view of the valve disk of the flow path switching valve. Fig. 5 is a side view of the valve disk of the flow path switching valve. Fig. 6 is a rear view of the valve disk of the flow path switching valve. Fig. 7 is a cross-sectional view taken along line A-A in Fig. 4. Fig. 8 is a cross-sectional view taken along line B-B in Fig. 4. Each figure shows a first axis C1 that coincides with the rotation axis C of the valve disk 60, a second axis C2 that is perpendicular to the first axis C1, and a third axis C3 that is perpendicular to the first axis C1 and the second axis C2. The first to third axes C1-C3 intersect at the center P of the spherical shape of the valve disk 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 passes through the valve body 60. In contrast, the recess 62 is formed by recessing the outer surface of the valve body 60.

[0039] The through hole 61 opens at two locations 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 side opposite the drive shaft 66, on the first axis C1. The other opening 61b is formed on the second axis C2. Therefore, as shown in FIG. 7 , the through hole 61 has a substantially L-shaped bent shape. The areas of both openings 61a and 61b are the same. The cross-sectional area of ​​the through hole 61 (the area of ​​a cross section perpendicular to the center line of the through hole 61; the 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 or 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 over a range (a range of 180° around the first axis C1) between a first position G1 located on the third axis C3 and a second position G2 located on the opposite side of the third axis C3 from the first position G1. 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 61 a, 61 b ​​of the through-hole 61.

[0041] In this embodiment, the bottom surface of the recess 62 is formed by a plurality of planes H1, H2, and H3. Specifically, the bottom surface of the recess 62 is formed by 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 does not have to be formed by a plurality of planes and may be a curved surface that curves around the first axis C1.

[0042] The valve body 60 is not a perfect sphere but has a portion of its spherical surface missing due to the through-hole 61 and recess 62. In Figures 4 to 8, the shape of a perfect sphere without missing portions 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 as the valve body 60 rotates 180° about 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" drawn into the compressor 15 flows.

[0044] 2B , the packings 36 provided between the first, second, and third ports P1, P2, and P3 and the valve body 60 are in close contact with the outer surface of the valve body 60 around the entire periphery of each opening 61 a, 61 b ​​of the through hole 61. Therefore, the packings 36 prevent 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 from leaking 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 as the valve body 60 rotates 180° about 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 disc 60 is in close contact with the outer surface of the valve disc 60 around the recess 62. However, because the recess 62 is formed continuously on the outer surface of the valve disc 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. As a result, a gap S is formed between the packing 36 and the outer surface of the valve disc 60. When 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 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 disc 60 within the hollow portion 31A. Therefore, it is possible to prevent the load torque for rotating the valve element 60 from becoming excessively large due to the outer surface of the valve element 60 coming into strong local contact with a portion of the packing 36. This allows the drive unit 64 to have a small output.

[0047] 9A and 9B are diagrams illustrating the operation of the flow path switching valve. The valve element 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 element 60, and the fourth port P4 and the third port P3 are connected by the recess 62. Therefore, as shown by the solid arrows in FIG. 1 , refrigerant discharged from the compressor 15 flows into the four-way switching valve 18 from the fourth port P4 and flows out of the four-way switching valve 18 from the third port P3 to be supplied to the outdoor heat exchanger 16. The refrigerant that flows 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 drawn into the compressor 15. This enables the air conditioner 10 to perform cooling operation.

[0048] 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 indicated by the dotted arrows in FIG. 1 , refrigerant discharged from the compressor 15 flows into the four-way switching valve 18 from the fourth port P4 and flows out of the four-way switching valve 18 from the second port P2 to be supplied to the indoor heat exchanger 21. Refrigerant flowing out of the outdoor heat exchanger 16 flows into the four-way switching valve 18 from the third port P3 and flows out of the four-way switching valve 18 from the first port P1 to be drawn into the compressor 15. This enables the air conditioner 10 to perform 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. To suppress such pressure loss, it is desirable to increase the cross-sectional area (the area of ​​a cross section perpendicular to the refrigerant flow; 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 multiple 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, with the through hole 61 serving as a flow path for the low-pressure refrigerant and the recess 62 serving 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 the recess 62 can be formed closer to the outer surface of the valve body 60. This allows the remaining portion of the valve body 60 other than the recess 62 to be made larger, and this remaining portion can be used to form the through hole 61 (flow path for the low-pressure refrigerant) 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 possible to increase the outer diameter of the valve element 60 itself. However, adopting such a measure would result in an increase in the size of the four-way selector valve 18. Furthermore, adopting such a measure would increase the contact area of ​​the packing 36 with the valve element 60, which would increase the load torque for rotating the valve element 60 due to frictional resistance, and would require a higher output from the drive unit 64.

[0052] FIG. 10 is a schematic graph showing the relationship between the outer diameter of the valve disc of the flow path switching valve and the cross-sectional area of ​​the low-pressure refrigerant flow path that can be formed in the valve disc. The solid line in FIG. 10 represents the graph for this embodiment, in which a through-hole 61 and a recess 62 are formed in the valve disc 60 as the refrigerant flow path. The dotted line in FIG. 10 represents the graph for the prior art (e.g., Patent Document 1), in which two through-holes are formed in the valve disc as the refrigerant flow path. In FIG. 10 , when the cross-sectional area of ​​the low-pressure refrigerant flow path is value A, the prior art requires the outer diameter of the valve disc to be a2. However, in this embodiment, the outer diameter of the valve disc 60 can be a1, which is smaller than a2. In other words, in this embodiment, a valve disc 60 with a smaller outer diameter can be used to form the through-hole 61 with a larger cross-sectional area, compared to the prior art. 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, it is possible to increase the volume of the through hole 61 up to 69% of the volume of the valve body 60. The volume of the through hole 61 is preferably 50% or more, and more preferably 60% or more, of the volume of the valve body 60. In this specification, the volume of the through hole 61 refers to 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 refers to the volume of the space surrounded by the bottom surface and side surfaces that form the recess 62. The volume of the valve body 60 refers to the substantial volume of the valve body 60 excluding the volumes of the through hole 61 and 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 this 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 this 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 has 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 by recessing the outer surface of the valve body 60.

[0057] The through hole 61 is open at two locations 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 Figure 13, the through hole 61 has a substantially L-shaped bend.

[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 a first position G1 located on the opposite side of the first axis C1 from one opening 61a of the through hole 61, and a second position G2 located on the opposite side of the second axis C2 from the other opening 61b of the through hole 61.

[0059] The bottom surface of the recess 62 in this embodiment is formed by a plurality of planes H1 and H2. Specifically, the bottom surface of the recess 62 is formed by 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 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 four or more planes. The bottom surface of the recess 62 does not have to be formed by a plurality of planes and may be a curved surface curved about the first axis C1.

[0060] The valve body 60 is not a perfect sphere but has a missing portion due to the through-hole 61 and the recess 62. In Fig. 13, the shape of a perfect sphere without a missing portion is shown by the imaginary line L.

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

[0062] 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 indicated by the dotted arrows in FIG. 1 , 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. 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 drawn into the compressor 15. This enables the air conditioner 10 to perform heating operation.

[0063] In this embodiment as well, 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, making it possible to make the four-way switching valve 18 smaller in size in the direction of the rotation axis C than in the first embodiment.

[0065] In the above embodiment, the high-pressure refrigerant flowing through the fourth port P4 and the second or third port P2, P3, which are connected by 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 also 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 or cylindrical shape, etc. The hollow portion 31A of the casing 31 may also be formed in a cubic or cylindrical shape, etc.

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

[0069] [Operation and Effects of the Embodiment] (1) The flow path switching valve 18 of the present disclosure includes a housing (casing) 31 having a hollow portion 31A therein, and a valve element 60 that is rotatably housed in the hollow portion 31A and that can be switched between a first position and a second position by being rotated. The housing 31 is formed with 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 housing 31. The valve body 60 is formed 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 drawn 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 with the second opening P2 in the second position and has a recessed shape on the outer surface of the valve body 60. As described above, the valve body 60 of this embodiment is formed with the through-hole 61 and the recess 62, rather than multiple through-holes. This allows the volume of the through-hole 61 relative to the entire valve body 60 to be increased, and the cross-sectional area of ​​the through-hole 61 to be increased. This reduces 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 accommodation body 31 is formed with a fourth opening (fourth port) P4 that connects the hollow portion 31A with the outside of the accommodation 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 flow using 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 recess 62 through which the high-pressure refrigerant flows is formed on the outer surface of the valve body 60, 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. Therefore, the cross-sectional area of ​​the flow path of the low-pressure refrigerant formed 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 includes 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 required to rotate the valve body 60 can be reduced.

[0073] (5) In the flow path switching valve 18 of the first embodiment, as shown in FIGS. 3 to 7 , on the outer surface of the valve body 60, one end of the through hole 61 opens on a 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 a second axis C2 that is perpendicular to the first axis C1. On the outer surface of the valve body 60, a recess 62 is formed in a range spanning from a first position G1 located on a third axis C3 that is perpendicular to the first axis C1 and the second axis C2, to a second position G2 located on the opposite side of the third axis C3 from 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 Figures 12 and 13, on the outer surface of the valve body 60, one end of the through hole 61 opens on a first axis C1 that is 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 that is 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 spanning from a first position G1 that is located on the opposite side of the first axis C1 from the one end of the through hole 61 to a second position G2 that is located on the opposite side of the second axis C2 from 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 can be made without departing from the spirit and scope of the claims.

[0076] 10: Refrigeration cycle device 15: Compressor 18: Four-way switching valve (flow path switching valve) 30: Refrigerant circuit 31: Container (casing) 31A: Hollow portion 60: Valve body 61: Through hole 62: Recessed portion C: Rotation axis C1: First axis C2: Second axis C3: Third axis G1: First position G2: Second position P1: First port (first opening) P2: Second port (second opening) P3: Third port (third opening) P4: Fourth port (fourth opening) S: Gap (leakage portion)

Claims

1. A refrigerant compressor comprising: a container (31) having a hollow portion (31A) therein; and a valve body (60) rotatably contained in the hollow portion (31A) and 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) communicating the hollow portion (31A) with the outside of the container (31) are formed in the container (31); a through hole (61) in the valve body (60) 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, the recess (62) having a recessed shape in an outer surface of the valve body (60).

2. A flow path changeover valve as described in claim 1, wherein a fourth opening (P4) is formed in the container (31) connecting the hollow portion (31A) with the outside of the container (31), and 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. A flow path switching valve as described in claim 1 or 2, wherein the volume of the through hole (61) is 28% or more and 69% or less of the volume of the valve body (60).

4. A flow path switching valve as described in 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. A flow path switching valve as claimed in any one of claims 1 to 4, wherein, on an outer surface of the valve body (60), one end of the through hole (61) opens on a first axis (C1) which 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), and the recess (62) is formed on the outer surface of the valve body (60) in a range spanning a first position (G1) arranged on a third axis (C3) perpendicular to the first axis (C1) and the second axis (C2) and a second position (G2) arranged on the opposite side of the third axis (C3) from the first position (G1).

6. A flow path switching valve as claimed in any one of claims 1 to 4, wherein, 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), and the recess (62) is formed on the outer surface of the valve body (60) in a range spanning a first position (G1) located on the opposite side on the first axis (C1) to the one end of the through hole (61) and a second position (G2) located on the opposite side on the second axis (C2) to the other end of the through hole (61).

7. A refrigeration cycle device comprising a flow path switching valve (18) according to any one of claims 1 to 6.

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