Flow path switching unit

Abstract

The structure of the flow path switching unit will be simplified. [Solution] The valve comprises a valve body 60 having a first passage 61 through which a refrigerant flows, and a casing 31 having a hollow portion 31A inside which the valve body 60 is rotatably housed, and a first refrigerant flow path 36b that can communicate with the first passage 61. A sealing portion 34a is integrally formed on either the periphery of the first refrigerant flow path 36b on the inner surface of the hollow portion 31A, or the periphery of the first passage 61 on the outer surface 60a of the valve body 60, in contact with the other.

Description

Technical Field

[0001] The present disclosure relates to a flow path switching unit.

Background Art

[0002] Patent Document 1 discloses an air conditioner that switches between cooling and heating. This air conditioner includes a flow path switching valve that switches the refrigerant discharged from the compressor to flow through either the outdoor heat exchanger or the indoor heat exchanger. This flow path switching valve includes a housing having a hollow portion inside and a plurality of openings for allowing the refrigerant to flow in or out, and a valve body rotatably accommodated in the hollow portion and having a refrigerant flow path formed therein. The housing has a casing and a packing accommodated inside the casing, and the packing prevents leakage of the refrigerant from between the opening of the housing and the flow path of the valve body by contacting the outer peripheral surface of the valve body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the flow path switching valve of Patent Document 1, since the packing is accommodated inside the casing, the number of parts increases, and since it is necessary to form a structure for attaching the packing inside the casing, the structure becomes complicated.

[0005] An object of the present disclosure is to simplify the structure of the flow path switching unit.

Means for Solving the Problems

[0006] (1) The flow path switching unit of the present disclosure includes a valve body in which a first passage through which the refrigerant flows is formed, The casing comprises a hollow portion inside which the valve body is rotatably housed, and a first refrigerant flow path formed therein that is able to communicate with the first passage, A sealing portion is integrally formed on either the periphery of the first refrigerant flow path on the inner surface of the hollow portion, or the periphery of the first passage on the outer surface of the valve body, in contact with the other.

[0007] According to the above configuration, leakage of refrigerant flowing through the first passage and the first refrigerant flow path is suppressed by the seal portion, and since the seal portion is formed integrally with the casing or valve body, the number of parts of the flow path switching unit can be reduced and the structure can be simplified.

[0008] (2) In the flow path switching unit of (1) above, the sealing portion is an annular projection.

[0009] With the above configuration, since the sealing portion is made up of an annular projection, the surface pressure can be increased and the sealing performance can be improved by bringing the tip of the projection into contact with the outer surface of the valve body or the inner surface of the hollow portion of the casing.

[0010] (3) In the flow path switching unit of (1) above, the seal portion is an annular projection formed on the inner surface of the hollow portion around the first refrigerant flow path.

[0011] With the above configuration, since the sealing portion is made up of an annular projection, the surface pressure can be increased by bringing the tip of the projection into contact with the outer surface of the valve body or the inner surface of the hollow part of the casing, thereby improving sealing performance. Since the sealing portion is provided on the stationary casing rather than on the rotating valve body, wear of the sealing portion can be suppressed.

[0012] (4) In any one of the flow path switching units of (1) to (3) above, a second passage is formed in the valve body through which a refrigerant at a higher pressure than the refrigerant flowing through the first passage flows, A second refrigerant flow path, which can communicate with the second passage, is formed in the casing.

[0013] With the above configuration, leakage of the refrigerant (low-pressure refrigerant) flowing through the first passage and the first refrigerant flow path is suppressed by the seal portion, and mixing of this low-pressure refrigerant with the refrigerant (high-pressure refrigerant) flowing through the second passage and the second refrigerant flow path can be suppressed. In addition, the high-pressure refrigerant flowing through the second passage and the second refrigerant flow path can strongly press the seal portion against the valve body or casing, thereby improving the sealing performance of the seal portion.

[0014] (5) In any one of the flow path switching units described in (1) to (4) above, the material of the casing and the valve body on which the seal portion is formed has a lower tensile modulus than the material of the other.

[0015] According to the above configuration, it is possible to suppress wear on the other by a seal formed on one of the casing and the valve body.

[0016] (6) In any one of the flow path switching units described in (1) to (5) above, the casing or valve body on which the seal portion is formed is made of synthetic resin.

[0017] According to the above configuration, the sealing portion can be easily formed integrally by mold molding or the like.

[0018] (7) In any one of the flow path switching units of (1) to (6) above, a second passage through which the refrigerant flows is formed in the valve body, The casing is provided with a third refrigerant flow path and a fourth refrigerant flow path that can communicate with the first passage and the second passage. The valve body is switched between a first mode and a second mode by rotational operation. The first passage is, In the first embodiment, it connects the first refrigerant passage and the third refrigerant passage, and in the second embodiment, it connects the first refrigerant passage and the fourth refrigerant passage, and is a through-hole through which low-pressure refrigerant drawn into the compressor of the refrigerant circuit flows. The aforementioned second passage is It communicates with the fourth refrigerant flow path in the first aspect, communicates with the third refrigerant flow path in the second aspect, and is a recess having a shape that depresses the outer surface of the valve body.

[0019] According to the above configuration, since the recess, which is the second passage, is formed by depressing the outer surface of the valve body, the volume occupied by the valve body as a whole can be reduced. Accordingly, the volume of the through-hole, which is the first passage, occupied by the valve body as a whole can be increased, and the flow path cross-sectional area of the through-hole can be ensured. Therefore, the pressure loss of the low-pressure refrigerant flowing through the through-hole can be reduced.

[0020] (8) In the flow path switching unit of (7) above, a second seal portion that contacts the other is integrally formed on one of the peripheries of the third refrigerant flow path and the fourth refrigerant flow path on the inner surface of the hollow portion and the periphery of the first passage on the outer surface of the valve body.

[0021] According to the above configuration, leakage of the refrigerant flowing through the first passage and the third refrigerant flow path or the fourth refrigerant flow path is suppressed by the second seal portion, and since the second seal portion is integrally formed with the casing, the number of parts of the flow path switching unit can be reduced and the structure can be simplified.

[0022] (9) In any one of the flow path switching units of (1) to (8) above, the casing has a plurality of divided bodies that form the hollow portion by combining with each other, and a metal outer casing that covers the outside of the plurality of divided bodies.

[0023] According to the above configuration, by covering the outside of the plurality of divided bodies with the metal outer casing, it is possible to suppress the refrigerant leaking from between the plurality of divided bodies to the outside of the flow path switching unit, and further, the pressure resistance of the plurality of divided bodies can be supplemented by the outer casing.

[0024] (10) The flow path switching unit of (9) above further includes a pipe inserted into the first refrigerant flow path formed in the divided body, and a third seal portion is formed at a portion of the first refrigerant flow path that contacts the pipe.

[0025] According to the above configuration, it is possible to suppress the backflow of refrigerant leaking from between the multiple divided parts through the gap between the outer casing and the divided parts, and through the gap between the first refrigerant flow path formed in the divided parts and the pipe to the valve body side (hollow part side). [Brief explanation of the drawing]

[0026] [Figure 1] This is a schematic diagram showing a refrigerant circuit of a refrigeration cycle device including a flow path switching unit according to the first embodiment of the present disclosure. [Figure 2] This is a perspective view of the flow path switching unit. [Figure 3] This is an exploded perspective view of the flow path switching unit. [Figure 4] This is a perspective view of the divided inner casing of the flow path switching unit. [Figure 5] This is a perspective view of the valve body of the flow path switching unit. [Figure 6] This is a cross-sectional view of the flow path switching unit. [Figure 7] This is a cross-sectional view illustrating the operation of the flow path switching unit in the first embodiment. [Figure 8] This is a cross-sectional view illustrating the operation of the flow path switching unit in the second embodiment. [Figure 9] This is a perspective view showing the valve body of a flow path switching unit according to the second embodiment. [Figure 10] This is a perspective view of a flow path switching unit according to a third embodiment. [Figure 11] This is a cross-sectional view of a flow path switching unit according to a third embodiment. [Modes for carrying out the invention]

[0027] The embodiments of this disclosure will be described in detail below with reference to the attached drawings. [First Embodiment] Figure 1 is a schematic diagram showing a refrigerant circuit of a refrigeration cycle device including a flow path switching unit according to the first embodiment of the present disclosure. The refrigeration cycle device 10 is equipped with a refrigerant circuit 30 that performs vapor compression type refrigeration cycle operation. The refrigeration cycle device 10 in this embodiment is an air conditioner. As shown in Figure 1, this 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 refrigerant circuit 30 is formed by the outdoor unit 11, the indoor unit 12, and the connecting pipes 13 and 14. Note that the refrigeration cycle device 10 is not limited to an air conditioner, but may be a refrigerator, freezer, water heater, ventilation device, etc.

[0028] (Refrigerant circuit configuration) As shown in Figure 1, the outdoor unit 11 is equipped 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 unit) 18, which constitute the refrigerant circuit 30. The outdoor unit 11 is also equipped with an outdoor fan 19. The indoor unit 12 is equipped with an indoor heat exchanger (utilizing heat exchanger; first heat exchanger) 21, which constitutes the refrigerant circuit 30. The indoor unit 12 is also equipped with an indoor fan 22.

[0029] The compressor 15 is a positive displacement compressor, such as a scroll type or rotary type, and has a built-in compressor motor. The compressor 15 compresses the low-pressure refrigerant drawn in from the suction pipe 52 and then discharges it from the discharge pipe 51. In the outdoor unit 11, the discharge side of the compressor 15 is connected to port A of the four-way switching valve 18 via the discharge pipe 51. The suction side of the compressor 15 is connected to port B of the four-way switching valve 18 via the suction pipe 52.

[0030] The outdoor heat exchanger 16 is composed of a cross-fin type fin-and-tube heat exchanger or a microchannel type heat exchanger, etc. The gas side end of the outdoor heat exchanger 16 is connected to port C of the four-way switching valve 18 via refrigerant piping 53. The liquid side end of the outdoor heat exchanger 16 is connected to one end of the expansion valve 17 via refrigerant piping 54.

[0031] The expansion valve 17 is, for example, an electrically operated valve with an adjustable opening. The other end of the expansion valve 17 is connected to the liquid side shut-off valve 23 via the refrigerant piping 55.

[0032] The indoor heat exchanger 21 is composed of 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 the liquid side shut-off valve 23 via the liquid side connecting pipe 14. The gas side end of the indoor heat exchanger 21 is connected to the gas side shut-off valve 24 via the gas side connecting pipe 13. The gas side shut-off valve 24 is connected to port D of the four-way switching valve 18 via the refrigerant pipe 56.

[0033] The four-way switching valve 18 switches the flow path between a first mode (shown by a solid line in Figure 1) in which ports A and C are in communication with each other and ports B and D are in communication with each other, and a second mode (shown by a dotted line in Figure 1) in which ports A and D are in communication with each other and ports B and C are in communication with 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.

[0034] The outdoor fan 19 is positioned near the outdoor heat exchanger 16. The outdoor fan 19 is driven by a motor to rotate and blow air onto the outdoor heat exchanger 16. The refrigerant flowing through the outdoor heat exchanger 16 exchanges heat with the outdoor air supplied by the outdoor fan 19, causing it to evaporate or condense.

[0035] The indoor fan 22 is positioned near the indoor heat exchanger 21. The indoor fan 22 is driven by a motor to rotate and blow air into the indoor heat exchanger 21. The refrigerant flowing through the indoor heat exchanger 21 exchanges heat with the indoor air supplied by the indoor fan 22, and condenses or evaporates.

[0036] The air conditioner 10 switches the four-way diverter valve 18 to a first mode when performing cooling operation, and switches the four-way diverter valve 18 to a second mode when performing heating operation. In cooling operation, the gaseous refrigerant discharged from the compressor 15 flows into the outdoor heat exchanger 16, which functions as a condenser, via the four-way diverter valve 18, and is condensed into liquid refrigerant. This liquid refrigerant is depressurized in the expansion valve 17 to become a gas-liquid two-phase refrigerant and flows into the indoor heat exchanger 21, which functions as an evaporator. The gas-liquid two-phase refrigerant exchanges heat with the air supplied by the indoor fan 22 and evaporates, becoming gaseous refrigerant. The air cooled by heat exchange is supplied to the room. The gaseous refrigerant flowing out of the indoor heat exchanger 21 is drawn into the compressor 15 via the four-way diverter valve 18.

[0037] During heating operation, the gaseous refrigerant discharged from the compressor 15 flows into the indoor heat exchanger 21, which functions as a condenser, via the four-way switching valve 18. The gaseous refrigerant condenses by exchanging heat with the air supplied by the indoor fan 22, becoming a liquid refrigerant. The air heated by the heat exchange is supplied to the room. The liquid refrigerant flowing out of the indoor heat exchanger 21 is depressurized in the expansion valve 17 to become a gas-liquid two-phase refrigerant, which flows into the outdoor heat exchanger 16, which functions as an evaporator. The gas-liquid two-phase refrigerant evaporates in the outdoor heat exchanger 16, becoming a gaseous refrigerant. The gaseous refrigerant is drawn into the compressor 15 via the four-way switching valve 18.

[0038] (Configuration of the four-way switching valve (flow path switching unit) 18) Figure 2 is a perspective view of the flow path switching unit. Figure 3 is an exploded perspective view of the flow path switching unit. Figure 6 is a cross-sectional view of the flow path switching unit. The four-way switching valve 18, which is a flow path switching unit, has a casing 31, a valve body 60, a drive unit 64, and a drive shaft 66. The casing 31 houses the valve body 60 inside. The casing 31 is formed in a substantially cylindrical shape. The casing 31 has two end faces located at both ends in a direction parallel to the central axis C1 of the cylinder (hereinafter also referred to as the axial direction), and a cylindrical outer surface located between the two end faces. The casing 31 has a hollow portion 31A (see Figure 6) for housing the valve body 60 inside. The hollow portion 31A is formed in a spherical shape.

[0039] The casing 31 includes an inner casing 32 and an outer casing (outer shell) 33. The inner casing 32 is formed in a substantially cylindrical shape. The aforementioned hollow portion 31A is formed inside the inner casing 32. The hollow portion 31A is located at the axial and radial center of the inner casing 32. The inner casing 32 is formed of, for example, a synthetic resin. The inner casing 32 is formed by mold molding such as injection molding. The material of the inner casing 32 can be PA66 (polyamide 66), PPS (polyphenylene sulfide), PBT (polybutylene terephthalate), etc. However, the material and manufacturing method of the inner casing 32 are not limited to the above. For example, the inner casing 32 may be formed by die casting or the like using a material mainly composed of aluminum.

[0040] The inner casing 32 of this embodiment is composed of a plurality of divided parts 32A. The inner casing 32 is divided by a plane that intersects (orthogonals) the central axis C1. More specifically, the inner casing 32 is divided into two parts at the center in the axial direction by a plane that is orthogonal to the central axis C1. Therefore, the inner casing 32 is composed of two divided parts 32A. The inner casing 32 may also be composed of a plurality of divided parts divided by a plane that passes through the central axis C1 or by a plane that is parallel to the central axis C1.

[0041] Figure 4 is a perspective view of the divided parts of the inner casing of the flow path switching unit. As shown in Figures 3 and 4, the two divided bodies 32A are formed to be the same shape and are arranged opposite to each other in the axial direction. The inner casing 32 is constructed by combining the two divided bodies 32A with their axial end faces 32A1 facing each other. A hemispherical recess 32A2 is formed on one axial end face 32A1 of each divided body 32A, and a spherical hollow portion 31A is formed by combining the two recesses 32A2.

[0042] The outer casing 33 covers the outside of the inner casing 32. The outer casing 33 is formed in a substantially cylindrical shape. The outer casing 33 has a cylindrical body portion 33A and ends 33B that close both ends of the body portion 33A in the axial direction. The outer casing 33 is made of metal. The outer casing 33 is made of stainless steel, iron, etc. The outer casing 33 is formed by sheet metal processing, etc. However, the material and manufacturing method of the outer casing 33 are not limited to those described above.

[0043] The body portion 33A and end portion 33B of the outer casing 33 are connected by welding or brazing. The body portion 33A and end portion 33B are tightly joined to prevent refrigerant leakage between them. The outer casing 33 protects the inner casing 32 by covering its exterior. The outer casing 33 also enhances the pressure resistance of the inner casing 32 against the refrigerant pressure applied to it.

[0044] Ports A, B, C, and D are provided on both axial ends of the casing 31. Each of ports A to D corresponds to the ports A to D described with reference to Figure 1. In this embodiment, ports A to D are formed in a tubular shape. Other refrigerant pipes 51 to 53 and 56 are connected to each of ports A to D.

[0045] Ports A to D are metal pipes. For example, ports A to D are pipes primarily composed of copper, such as copper alloy or pure copper. However, the material of ports A to D is not limited, and materials primarily composed of aluminum, such as aluminum alloy or pure aluminum, stainless steel, iron, etc., may also be used. The ends of ports A to D, to which other refrigerant pipes 51 to 53 and 56 are connected, may be flared.

[0046] Ports A to D may be composed not of pipes, but of refrigerant flow paths 36a to 36d (see Figure 6; details will be described later) that open at the end faces of the casing 31.

[0047] Ports B and C are provided on one end face 33B1 of the casing 31. Ports A and D are provided on the other end face 33B2 of the casing 31. As shown in Figure 6, each of ports A to D communicates with refrigerant passages 36a, 36b, 36c, and 36d that penetrate the casing 31 between the end faces 33B1, 33B2 and the hollow portion 31A. The refrigerant passages 36a to 36d are formed substantially parallel to the central axis C1. Each of ports A to D is inserted into and fixed in the refrigerant passages 36a, 36b, 36c, and 36d. Ports A to D are each fixed to the outer casing 33 by brazing or welding.

[0048] Figure 5 is a perspective view of the valve body of the flow path switching unit. As shown in Figures 5 and 6, the valve body 60 is positioned in the hollow portion 31A of the casing 31. The valve body 60 is formed in a spherical shape. The outer diameter of the valve body 60 is formed to be slightly smaller than the inner diameter of the inner surface of the hollow portion 31A.

[0049] The valve body 60 is made of synthetic resin or metal. The valve body 60 is formed by mold molding, such as injection molding or die casting. Examples of materials used for the valve body 60 include synthetic resins such as PA66 (polyamide 66) and PPS (polyphenylene sulfide), aluminum alloys, materials mainly composed of aluminum such as pure aluminum (hereinafter also simply referred to as "aluminum"), and steel materials such as SUJ2 (high-carbon chromium bearing steel). However, the material and manufacturing method of the valve body 60 are not limited to these.

[0050] The valve body 60 is formed from a material with a higher tensile modulus than the material of the inner casing 32. The materials listed as possible for use in the inner casing 32 and the valve body 60—SUJ2, aluminum, PA66, PPS, and PBT—have decreasing tensile moduli in this order. Therefore, the materials for the inner casing 32 and the valve body 60 can be selected according to the order of these tensile moduli. For example, if the material of the valve body 60 is PPS, PBT can be selected as the material for the inner casing 32, and if the material of the valve body is PA66, PPS or PBT can be selected as the material for the inner casing 32.

[0051] By forming the valve body 60 from a material with a higher tensile modulus than the material of the inner casing 32, wear of the valve body 60 due to contact with the seal portions 34a to 34d (details to be described later) formed on the inner casing 32 can be suppressed.

[0052] As shown in Figures 2 and 5, the valve body 60 rotates around a predetermined rotation axis C2. The rotation axis C2 of the valve body 60 passes through the spherical center P of the valve body 60 and intersects (is perpendicular to) the central axis C1 of the casing 31. A drive shaft 66 is positioned on the rotation axis C2. The drive shaft 66 is positioned on the outer circumferential surface of the casing 31. The drive shaft 66 penetrates the casing 31 between the outer circumferential surface 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 is connected to the drive shaft 66. The drive shaft 66 is installed in a sealed state with a sealing member or the like to prevent refrigerant leakage between it and the casing 31.

[0053] The drive unit 64 is, for example, an electric motor. The drive unit 64 generates and outputs rotational power. The drive unit 64 employs an electric motor, such as a stepping motor, that can adjust the rotation angle of the drive shaft 66. The drive unit 64 is controlled by the controller of the air conditioner 10 and drives the valve body 60 according to the operating state of the air conditioner 10.

[0054] (Specific structure of the valve body) Figures 5 and 6 show a reference axis C3 perpendicular to the rotation axis C2 of the valve body 60, and a reference axis C4 perpendicular to both the rotation axis C2 and the reference axis C3. The rotation axis C2, the reference axis C3, and the reference axis C4 intersect each other at the spherical center P of the valve body 60.

[0055] The valve body 60 has a through hole 61 and a recess 62. Both the through hole 61 and the recess 62 constitute passages 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 60a of the valve body 60.

[0056] The through-hole 61 is formed at two locations on the outer surface 60a of the valve body 60. One opening 61a of the through-hole 61 is formed on the reference axis C3. The other opening 61b is formed on the reference axis C4. Therefore, as shown in Figure 6, the through-hole 61 is formed in a roughly L-shaped bend. The areas of both openings 61a and 61b are the same. The cross-sectional area of ​​the through-hole 61 (the area of ​​the cross section perpendicular to the center line of the through-hole 61; the cross-sectional area) is approximately the same as the area of ​​each opening 61a and 61b.

[0057] The recess 62 is formed on the outer surface 60a of the valve body 60 over a range (approximately 90° around the rotation axis C2) that spans from position G1, located on the opposite side of the reference axis C3 with respect to one opening 61a of the through hole 61, to position G2, located on the opposite side of the reference axis C4 with respect to the other opening 61b of the through hole 61.

[0058] The bottom surface 62a of the recess 62 is a single flat surface. This bottom surface 62a is formed across positions G1 and G2. The bottom surface 62a may be composed of multiple flat surfaces or of curved surfaces. The bottom surface 62a of the recess 62 and the two openings of the through hole 61 are positioned at an angle of approximately 45°.

[0059] The valve body 60 is not a perfect sphere because of the formation of the through hole 61 and the recess 62, and is a sphere with a portion of its spherical surface (outer surface 60a) missing. In Figure 6, the shape of a perfect sphere without any missing portion is shown by the dashed line L.

[0060] (Switching of the flow path by the valve body 60) Figure 7 is a cross-sectional view illustrating the operation of the flow path switching unit in the first embodiment. Figure 8 is a cross-sectional view illustrating the operation of the flow path switching unit in the second embodiment. In this embodiment, the valve body 60 is switched between a first mode (see Figure 7) and a second mode (see Figure 8) by rotating 90 degrees around the rotation axis C2.

[0061] In the first embodiment shown in Figure 7, port B and port D are connected by a through-hole 61 of the valve body 60, and port A and port C are connected by a recess 62. Therefore, as shown by the solid arrows in Figure 1, the refrigerant discharged from the compressor 15 flows through the refrigerant piping 51 into the four-way directional control valve 18 from port A, and as shown in Figure 7, flows out of the four-way directional control valve 18 from port C after passing through the refrigerant flow paths 36a, 36c and the recess 62, and is supplied to the outdoor heat exchanger 16 via the refrigerant piping 53, as shown in Figure 1. The refrigerant that flows out from the indoor heat exchanger 21 flows through the connecting piping 13 into the four-way directional control valve 18 from port D, and as shown in Figure 7, flows out of the four-way directional control valve 18 from port B after passing through the refrigerant flow paths 36d, 36b and the through-hole 61, and is drawn into the compressor 15. This enables the air conditioner 10 to perform cooling operation.

[0062] In the second embodiment shown in Figure 8, port B and port C are connected by a through-hole 61 of the valve body 60, and port A and port D are connected by a recess 62. Therefore, as shown by the dotted arrow in Figure 1, the refrigerant discharged from the compressor 15 flows into the four-way directional control valve 18 from port A through the refrigerant piping 51, and as shown in Figure 8, flows out to the outside of the four-way directional control valve 18 from port D through the refrigerant flow paths 36a, 36d and the recess 62, and is supplied to the indoor heat exchanger 21 through the connecting pipe 13, as shown in Figure 1. The refrigerant that flows out from the outdoor heat exchanger 16 flows into the four-way directional control valve 18 from port C through the refrigerant piping 53, and as shown in Figure 8, flows out to the outside of the four-way directional control valve 18 from port B through the refrigerant flow paths 36c, 36b and the through-hole 61, and is drawn into the compressor 15 through the refrigerant piping 52. This enables the air conditioner 10 to perform heating operation.

[0063] The valve body 60 may be restricted from rotating so as to ensure it is reliably positioned at a predetermined rotational position in both the first and second embodiments. For example, a stopper may be provided on either the valve body 60 or the drive shaft 66 and the casing 31, and the rotation of the valve body 60 may be restricted by bringing the stopper into contact with the other. Figures 7 and 8 show an example in which a stopper 38 is provided on the inner casing 32 of the casing 31. In both the first and second embodiments, the stopper 38 contacts the valve body 60 to limit the amount of rotation of the valve body 60, thereby positioning the valve body 60 at a predetermined rotational position.

[0064] As shown in Figures 7 and 8, the through-hole 61 is always in communication with port B, and the valve body 60 rotates around the rotation axis C2 to selectively communicate with port D and port C. Since port B is connected to the suction pipe 52 of the compressor 15, the through-hole 61, which is always in communication with port B, becomes the passage (first passage) through which the "low-pressure refrigerant" flows.

[0065] The recess 62 is always in communication with port A, and the valve body 60 rotates around the rotation axis C2 to selectively communicate with port C and port D. Since port A is connected to the discharge pipe 51 of the compressor 15, the recess 62, which is always in communication with port A, becomes a passage (second passage) through which the "high-pressure refrigerant" flows.

[0066] (Structure of the sealing part) As shown in Figures 4 and 6, sealing portions 34a, 34b, 34c, and 34d are integrally formed on the inner surface of the hollow portion 31A of the casing 31, around each of the refrigerant flow paths 36a to 36d. For example, the sealing portions 34a to 34d are integrally formed with the inner casing 32 when the inner casing 32 is molded by injection molding or die casting. The sealing portions 34a to 34d are annular projections that protrude from the inner surface of the hollow portion 31A. The tips of these sealing portions 34a to 34d are in contact with the outer surface 60a of the valve body 60. In this embodiment, the sealing portions 34a to 34d are formed in a circular annular shape substantially along the periphery of the cylindrical refrigerant flow paths 36a to 36d. However, the sealing portions 34a to 34d may also be annular in shape, such as a rectangular shape.

[0067] Specifically, in the first embodiment shown in Figure 7, the seal portion 34b formed around the refrigerant flow path 36b on the inner surface of the hollow portion 31A is in contact with the area around the opening 61b of the through hole 61 on the outer surface 60a of the valve body 60. The seal portion 34d formed around the refrigerant flow path 36d on the inner surface of the hollow portion 31A is in contact with the area around the opening 61a of the through hole 61 on the outer surface 60a of the valve body 60.

[0068] Therefore, the sealing portions 34b and 34d can prevent the low-pressure refrigerant flowing through ports B and D, refrigerant passages 36b and 36d, and the through-hole 61 from leaking into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A. Similarly, the sealing portions 34b and 34d can prevent the refrigerant flowing through areas other than ports B and D, refrigerant passages 36b and 36d, and the through-hole 61 (high-pressure refrigerant) from flowing into ports B and D, refrigerant passages 36b and 36d, and the through-hole 61. This prevents the mixing of low-pressure and high-pressure refrigerants.

[0069] In contrast, the sealing portions 34a and 34c formed around the refrigerant flow paths 36a and 36c on the inner surface of the hollow portion 31A are partially in contact with the outer surface 60a of the valve body 60, but the other portion is located radially outward of the recess 62 and does not come into contact with the outer surface 60a of the valve body 60. Therefore, the high-pressure refrigerant flowing through ports A and C, the refrigerant flow paths 36a and 36c, and the recess 62 leaks into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A.

[0070] When high-pressure refrigerant leaks into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A, the pressure of the high-pressure refrigerant is applied to most of the outer surface 60a of the valve body 60, excluding the through hole 61. In addition, the pressure of the high-pressure refrigerant is also applied to the recess 62 through which the high-pressure refrigerant flows. As a result, the outer surface 60a of the valve body 60 is strongly pressed against the sealing portions 34b and 34d formed around the refrigerant flow paths 36b and 36d.

[0071] As a result, the sealing portions 34b and 34d can further suppress the leakage of low-pressure refrigerant flowing through ports B and D, refrigerant passages 36b and 36d, and the through-hole 61 into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A. Furthermore, the sealing portions 34b and 34d can further suppress the flow of high-pressure refrigerant flowing through areas other than ports B and D, refrigerant passages 36b and 36d, and the through-hole 61—in other words, high-pressure refrigerant flowing through ports A and C, refrigerant passages 36a and 36c, and the recess 62, as well as high-pressure refrigerant leaking from these areas—into ports B and D, refrigerant passages 36b and 36d, and the through-hole 61.

[0072] In the second embodiment shown in Figure 8, the seal portion 34b formed around the refrigerant flow path 36b on the inner surface of the hollow portion 31A is in contact with the area around the opening 61a of the through hole 61 on the outer surface 60a of the valve body 60. The seal portion 34c formed around the refrigerant flow path 36c on the inner surface of the hollow portion 31A is in contact with the area around the opening 61a of the through hole 61 on the outer surface 60a of the valve body 60.

[0073] Therefore, the sealing portions 34b and 34c can prevent the low-pressure refrigerant flowing through ports B and C, refrigerant passages 36b and 36c, and the through-hole 61 from leaking into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A. Furthermore, the sealing portions 34b and 34c can prevent the refrigerant flowing through areas other than ports B and C, refrigerant passages 36b and 36c, and the through-hole 61 (high-pressure refrigerant) from flowing into ports B and C, refrigerant passages 36b and 36c, and the through-hole 61. This prevents the mixing of low-pressure and high-pressure refrigerants.

[0074] In contrast, the sealing portions 34a and 34d formed around the refrigerant passages 36a and 36d on the inner surface of the hollow portion 31A are partially in contact with the outer surface 60a of the valve body 60, but the other portion is located radially outward of the recess 62 and does not come into contact with the outer surface 60a of the valve body 60. Therefore, the refrigerant flowing through ports A and D, the refrigerant passages 36a and 36d, and the recess 62 leaks into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A.

[0075] As mentioned above, when high-pressure refrigerant leaks into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A, the pressure of the high-pressure refrigerant is applied to most of the outer surface 60a of the valve body 60, excluding the through hole 61. In addition, the pressure of the high-pressure refrigerant is also applied to the recess 62 through which the high-pressure refrigerant flows. As a result, the valve body 60 is strongly pressed against the seal portions 34b and 34c formed around the refrigerant flow paths 36b and 36c.

[0076] As a result, the sealing portions 34b and 34c can further suppress the leakage of low-pressure refrigerant flowing through ports B and C, refrigerant passages 36b and 36c, and the through-hole 61 into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A. Furthermore, the sealing portions 34b and 34c can further suppress the flow of high-pressure refrigerant flowing through areas other than ports B and C, refrigerant passages 36b and 36d, and the through-hole 61—in other words, high-pressure refrigerant flowing through ports A and D, refrigerant passages 36a and 36d, and the recess 62, as well as high-pressure refrigerant leaking from these areas—into ports B and C, refrigerant passages 36b and 36c, and the through-hole 61.

[0077] The sealing portions 34a to 34d are integrally formed with the inner casing 32. Therefore, the number of parts can be reduced compared to when the sealing portions 34a to 34d are formed separately from the inner casing 32. Furthermore, since the inner casing 32 is made of synthetic resin, the sealing portions 34a to 34d can be easily molded integrally by mold molding.

[0078] Of the four ports A to D, only high-pressure refrigerant flows through port A, so the seal portion 34a formed around port A is not used in practice. Therefore, the seal portion 34a may be omitted. However, if the seal portion 34a is omitted, the two divided parts 32A that make up the inner casing 32 cannot be made from the same part. Therefore, from the viewpoint of manufacturing cost, it is preferable to form seal portions 34a to 34d around all ports A to D.

[0079] The divided sections 32A of the inner casing 32 are only butted together at their end faces 32A1 and are not bonded together. Therefore, as shown by arrow d in Figures 7 and 8, the high-pressure refrigerant leaks out of the inner casing 32 from between the end faces 32A1. The leaked high-pressure refrigerant flows into the inside of the outer casing 33, but since the outer casing 33 is tightly joined together by welding or the like by multiple divided sections (body section 33A, end section 33B), leakage from between these sections is suppressed.

[0080] The pipes, ports A to D, are inserted into openings 33B3 formed at the end 33B of the outer casing 33 and joined by welding or brazing. This prevents refrigerant leakage from between the outer surfaces of ports A to D and the outer casing 33.

[0081] Ports A to D, which are pipes, are inserted into refrigerant passages 36a to 36d in the inner casing 32. In this embodiment, a seal portion 37 is provided between the outer circumferential surface of the pipes constituting ports A to D and the refrigerant passages 36a to 36d. This seal portion 37 is formed annularly along the circumferential direction on the inner circumferential surface of the refrigerant passages 36a to 36d. The seal portion 37 is integrally formed on the inner circumferential surface of the refrigerant passages 36a to 36d.

[0082] Therefore, leakage from the end face 31A1 of the inner casing 32 and flowing between the outer surface of the inner casing 32 and the inner surface of the outer casing 33, as indicated by arrow d, is prevented from entering the hollow portion 31A through the refrigerant flow paths 36a to 36d and ports A to D. The seal portion 37, like the seal portions 34a to 34d, can be integrally molded when the divided body 32A of the inner casing 32 is molded.

[0083] The flow path switching unit 18 is assembled as follows: First, as shown in Figure 3, the valve body 60 is placed between the two divided parts 32A that make up the inner casing 32, and the end faces 32A1 are brought together. Next, the body portion 33A of the outer casing 33 is fitted onto the outer circumferential surface of the inner casing 32, and the end portion 33B of the outer casing 33 covers the end portion of the inner casing 32. At this time, ports A to D, which are fixed in advance to the end portion 33B of the outer casing 33, are inserted into the refrigerant flow paths 36a to 36d of the inner casing 32.

[0084] Next, the butt joint between the body portion 33A and the end portion 33B of the outer casing 33 is joined by welding or the like. Then, the drive shaft 66 (see Figure 2) is inserted into the holes 33C and 32C formed in the outer casing 33 and the inner casing 32 and connected to the valve body 60, and the drive unit 64 is attached to the drive shaft 66. A seal is applied between the drive shaft 66 and the outer casing 33 to prevent refrigerant leakage.

[0085] In the above assembly method, the process of bonding the two divided parts 32A that constitute the inner casing 32 by welding or the like is unnecessary. Therefore, the assembly work of the flow path switching unit 18 can be easily performed. The seal between the outer surface 60a of the valve body 60 and the inner surface of the hollow part 31A can be performed by the sealing parts 34b to 34d simply by housing the valve body 60 in the hollow part 31A of the inner casing 32. Similarly, the seal between the ports A to D and the refrigerant flow paths 36a to 36d can be performed by the sealing part 37 simply by inserting the ports A to D, which are fixed to the outer casing 33, into the refrigerant flow paths 36a to 36d of the inner casing 32. These also make the assembly work of the flow path switching unit 18 easy.

[0086] [Second Embodiment] Figure 9 is a perspective view showing the valve body of a flow path switching unit according to the second embodiment. In this embodiment, the valve body 60 of the flow path switching unit (four-way switching valve) 18 is formed in a cylindrical shape. The axis of the cylindrical shape of the valve body 60 becomes the rotation axis C2. The valve body 60 has through holes 61 and recesses 62, similar to those of the valve body 60 in the first embodiment. Although not shown, the hollow portion 31A of the casing 31 in which the valve body 60 is housed is also formed in a cylindrical shape. The configuration of the flow path switching unit 18 other than the valve body 60 and the hollow portion 31A is the same as in the first embodiment.

[0087] [Third Embodiment] Figure 10 is a perspective view of the flow path switching unit according to the third embodiment. Figure 11 is a cross-sectional view of the flow path switching unit according to the third embodiment. The flow path switching unit 18 in this embodiment has a rectangular parallelepiped shape. Tubular ports B and C are provided on the upper surface of the flow path switching unit 18, and tubular ports A and D are provided on the lower surface of the flow path switching unit 18. Refrigerant pipes 51, 52, 53, and 56 shown in Figure 1 are connected to each of the ports A to D.

[0088] The flow path switching unit 18 of this embodiment has a casing 31 and a valve body 60, similar to the first embodiment. The casing 31 has an inner casing 32 made of synthetic resin and an outer casing 33 made of metal. The materials and manufacturing methods of these are the same as in the first embodiment. The inner casing 32 is a rectangular parallelepiped block. The inner casing 32 is composed of a plurality of members (divided parts). The inner casing 32 is divided in the middle part in the vertical, front-back, or left-right direction.

[0089] The outer casing 33 covers the outside of the inner casing. The outer casing 33 is a hollow box in the shape of a rectangular parallelepiped.

[0090] Multiple refrigerant passages 36a to 36d are formed within the casing 31. The refrigerant passages 36a to 36d include horizontal passages 36a1, 36b1, 36c1, and 36d1 extending horizontally from the hollow section 31A, and vertical passages 36a2, 36b2, 36c2, and 36d2 extending vertically from the ends of each horizontal passage 36a1 to 36d1. The vertical passages 36b2 and 36c2 of the refrigerant passages 36b and 36c extend upward from the horizontal passages 36b1 and 36c1 and open at the top surface of the casing 31. The vertical passages 36a2 and 36d2 of the refrigerant passages 36a and 36d extend downward from the horizontal passages 36a1 and 36d1 and open at the bottom surface of the casing 31.

[0091] The flow path switching unit 18 of this embodiment is the same as that of the first embodiment, except for the configuration of the casing 31. Therefore, it provides the same effects and advantages as the flow path switching unit 18 of the first embodiment.

[0092] In this embodiment, ports B and D may be provided on surfaces other than the top surface (left and right sides, front and rear sides, and bottom surface), and ports A and D may be provided on surfaces other than the bottom surface (left and right sides, front and rear sides, and top surface).

[0093] [Other embodiments] In the above embodiment, the sealing portions 34a to 34d were formed on the inner surface of the hollow portion 31A in the inner casing 32, but they may also be integrally formed around the openings 61a and 61b of the through hole (passage) 61 in the valve body 60. In this case, the tips of the sealing portions 34a to 34d come into contact with the inner surface of the hollow portion 31A, thereby suppressing leakage of refrigerant into the gap between them. It is preferable that the valve body 60 on which the sealing portions are formed is made of a material with a lower tensile modulus than the material of the inner casing 32. This suppresses wear of the inner casing 32 due to contact with the sealing portions of the valve body 60.

[0094] In the flow path switching unit 18 of the above embodiment, the high-pressure refrigerant flowing through the recess 62 and the refrigerant flow paths 36a, 36c, and 36d is configured to leak into the gap between the inner surface of the hollow portion 31A and the outer surface 60a of the valve body 60, or to the outside of the inner casing 32. However, the flow path switching unit 18 may be configured to prevent such leakage.

[0095] In the above embodiment, the valve body 60 has a through hole 61 that constitutes a passage for low-pressure refrigerant and a recess 62 that constitutes a passage for high-pressure refrigerant. However, it is not limited to this. For example, the valve body 60 may have a recess formed as a passage for low-pressure refrigerant, or a through hole formed as a passage for high-pressure refrigerant. The valve body 60 is not limited to the spherical or cylindrical shape described above, but may have other shapes as well.

[0096] The rotation axis C2 of the valve body 60 may be oriented horizontally or vertically. The rotation axis C2 of the valve body 60 may be oriented in a direction inclined with respect to the vertical and horizontal directions.

[0097] In the above embodiment, the flow path switching unit 18 constituted a four-way switching valve, but it may also constitute a three-way switching valve.

[0098] In the valve body 60, the edges of the openings 61a and 61b of the through hole 61 can be chamfered in a tapered or rounded shape. This suppresses wear of the sealing portions 34a to 34d when the edges of the openings 61a and 61b come into contact with them. Furthermore, it suppresses the increase in rotational torque of the valve body 60 caused by the edges of the openings 61a and 61b catching on the sealing portions 34a to 34d when the valve body 60 rotates.

[0099] [Effects of the Embodiment] (1) The flow path switching unit 18 of the above embodiment comprises a valve body 60 having a first passage (e.g., a through hole 61) through which the refrigerant flows, and a casing 31 having a hollow portion 31A inside which the valve body 60 is rotatably housed, and having a first refrigerant flow path (e.g., a refrigerant flow path 36b) that can communicate with the first passage 61. A sealing portion (e.g., a sealing portion 34b) is integrally formed on either the periphery of the first refrigerant flow path 36b on the inner surface of the hollow portion 31A, or the periphery of the first passage 61 on the outer surface 60a of the valve body 60, in contact with the other.

[0100] With this configuration, leakage of refrigerant flowing through the first passage 61 and the first refrigerant flow path 36b is suppressed by the seal portion 34b, and since the seal portion 34b is formed integrally with the casing 31 or valve body 60, the number of parts of the flow path switching unit 18 can be reduced and the structure can be simplified.

[0101] (2) In the flow path switching unit 18 of (1) above, the seal portion 34b is an annular projection. With this configuration, since the sealing portion 34b is made up of an annular projection, the surface pressure can be increased and the sealing performance can be improved by bringing the tip of the projection into contact with the outer surface 60a of the valve body 60 or the inner surface of the hollow portion 31A of the casing 31.

[0102] (3) In the flow path switching unit 18 of (1) above, the seal portion 34b is an annular projection formed on the inner surface of the hollow portion 31A around the first refrigerant flow path 36b. With this configuration, since the sealing portion 34b is made up of an annular projection, the surface pressure can be increased and the sealing performance can be improved by bringing the tip of the projection into contact with the outer surface 60a of the valve body 60 or the inner surface of the hollow portion 31A of the casing 31. Since the sealing portion 34b is provided on the stationary casing 31 rather than on the rotating valve body 60, wear of the sealing portion 34b can be suppressed.

[0103] (4) In any one of the flow path switching units 18 described in (1) to (3) above, a second passage 62 is formed in the valve body 60 through which a refrigerant at a higher pressure than the refrigerant flowing through the first passage 61 flows, and a second refrigerant flow path 36a is formed in the casing 31 that can communicate with the second passage 62. With this configuration, leakage of the refrigerant (low-pressure refrigerant) flowing through the first passage 61 and the first refrigerant flow path 36b is suppressed by the seal portion 34b, thereby preventing the low-pressure refrigerant from mixing with the refrigerant (high-pressure refrigerant) flowing through the second passage 62 and the second refrigerant flow path 36a. Furthermore, the high-pressure refrigerant flowing through the second passage 62 and the second refrigerant flow path 36a can strongly press the seal portion 34b against the outer surface 60a of the valve body 60 or the inner surface of the hollow portion 31A, thereby improving the sealing performance of the seal portion 34b.

[0104] (5) In any one of the flow path switching units 18 described in (1) to (4) above, the material of the casing 31 and the valve body 60 on which the seal portion 34b is formed has a lower tensile modulus than the material of the other. This configuration makes it possible to prevent the seal portion 34b formed on one of the casing 31 and the valve body 60 from wearing down the other.

[0105] (6) In any one of the flow path switching units 18 described in (1) to (5) above, the casing 31 or valve body 60 on which the seal portion 34b is formed is made of synthetic resin. With this configuration, the sealing portion 34b can be easily formed integrally by mold molding or the like.

[0106] (7) In any one of the flow path switching units 18 described in (1) to (6) above, a second passage (for example, a recess 62) through which refrigerant flows is formed in the valve body 60, and a third refrigerant flow path 36d and a fourth refrigerant flow path 36c that can communicate with the first passage 61 and the second passage 62 are formed in the casing 31, and the valve body 60 is switched between the first and second modes by rotational operation. The first passage 61 connects the first refrigerant flow path 36b and the third refrigerant flow path 36d in the first mode, and connects the first refrigerant flow path 36b and the fourth refrigerant flow path 36c in the second mode, and is a through-hole through which low-pressure refrigerant drawn into the compressor 15 of the refrigerant circuit 30 flows. The second passage 62 communicates with the fourth refrigerant flow path 36c in the first mode, and communicates with the third refrigerant flow path 36d in the second mode, and is a recess in the shape of a recess on the outer surface 60a of the valve body 60.

[0107] With this configuration, the recess, which is the second passage 62, is formed by recessing the outer surface 60a of the valve body 60. This reduces the volume of the second passage 62 relative to the entire valve body 60, thereby increasing the volume of the through-hole, which is the first passage 61, relative to the entire valve body 60, and ensuring a sufficient flow path cross-sectional area for the through-hole 61. As a result, the pressure loss of the low-pressure refrigerant flowing through the through-hole 61 can be reduced.

[0108] (8) In the flow path switching unit 18 described in (7) above, a second sealing portion (e.g., sealing portions 34d, 34c) is integrally formed on one of the following: around the third refrigerant flow path (e.g., refrigerant flow path 36d) and the fourth refrigerant flow path (e.g., refrigerant flow path 36c) on the inner surface of the hollow portion 31A, and around the first passage 61 on the outer surface of the valve body 60, in contact with the other. With this configuration, leakage of refrigerant flowing through the first passage 61 and the third refrigerant flow path 36d or the fourth refrigerant flow path 36c is suppressed by the second seal portions 34d and 34c, and since the second seal portions 34d and 34c are formed integrally with the casing 31 or valve body 60, the number of parts of the flow path switching unit 18 can be reduced and the structure can be simplified.

[0109] (9) In any one of (1) to (8) above, the casing 31 has a plurality of divided bodies 32A that combine with each other to form a hollow portion 31A, and a metal outer shell (outer casing) 33 that covers the outside of the plurality of divided bodies 32A. With this configuration, by covering the outside of the multiple divided parts 32A with a metal outer casing 33, it is possible to suppress the leakage of refrigerant that leaks from between the multiple divided parts 32A to the outside of the flow path switching unit 18, and furthermore, the outer casing 33 can be used to supplement the pressure resistance of the multiple divided parts 32A.

[0110] (10) The flow path switching unit 18 described in (9) above further comprises a pipe (for example, a port B) inserted into the first refrigerant flow path 36b formed in the divided body 32A, and a third seal portion 37 is formed in the portion of the first refrigerant flow path 36b that is in contact with the pipe B. With this configuration, it is possible to suppress the backflow of refrigerant leaking from between the multiple divided bodies 32A through the gap between the outer casing 33 and the divided bodies 32A, and through the gap between the first refrigerant flow path 36b formed in the divided body 32A and the pipe B to the valve body 60 side (hollow portion 31A side).

[0111] Although embodiments have been described above, it should be understood that various modifications to the form and details are possible without departing from the spirit and scope of the claims. [Explanation of Symbols]

[0112] 15: Compressor 18: Flow path switching unit 30: Refrigerant Circuit 31: Casing 31A: Hollow part 32A: Split body 33: Outer casing (outer shell) 34a: Seal part 34b: Seal part 34c: Seal section (second seal section) 34d: Seal section (second seal section) 36a: Refrigerant flow path (second refrigerant flow path) 36b: Refrigerant flow path (first refrigerant flow path) 36c: Refrigerant flow path (4th refrigerant flow path) 36d: Refrigerant flow path (Third refrigerant flow path) 37: Seal section (third seal section) 60: Valve body 60a: Outer surface 61: Through hole (1st passage) 62: Recess (Second passage) B: Port (pipe)

Claims

1. A valve body (60) having a first passage (61) through which the refrigerant flows, The casing (31) has a hollow portion (31A) inside which the valve body (60) is rotatably housed, and a first refrigerant flow path (36b) that can communicate with the first passage (61) is formed therein. A flow path switching unit wherein a sealing portion (34a) is integrally formed on either the periphery of the first refrigerant flow path (36b) on the inner surface of the hollow portion (31A) or the periphery of the first passage (61) on the outer surface (60a) of the valve body (60), and the other is in contact with the other.

2. The flow path switching unit according to claim 1, wherein the sealing portion (34a) is an annular projection.

3. The flow path switching unit according to claim 1, wherein the sealing portion (34a) is an annular projection formed on the inner surface of the hollow portion (31A) around the first refrigerant flow path (36b).

4. A second passage (62) is formed in the valve body (60) through which a refrigerant at a higher pressure than the refrigerant flowing through the first passage (61) flows. A flow path switching unit according to any one of claims 1 to 3, wherein a second refrigerant flow path (36a) that can communicate with the second passage (62) is formed in the casing (31).

5. The flow path switching unit according to any one of claims 1 to 3, wherein the material of one of the casing (31) and the valve body (60) on which the seal portion (34a) is formed has a lower tensile modulus of elasticity than the material of the other.

6. The flow path switching unit according to any one of claims 1 to 3, wherein the casing (31) or valve body (60) on which the seal portion (34a) is formed is made of synthetic resin.

7. A second passage (62) through which the refrigerant flows is formed in the valve body (60). A third refrigerant flow path (36d) and a fourth refrigerant flow path (36c) are formed in the casing (31) that can communicate with the first passage (61) and the second passage (62). The valve body (60) is switched between a first mode and a second mode by rotational operation. The first passage (61) is In the first embodiment, it connects the first refrigerant passage (36b) and the third refrigerant passage (36d), and in the second embodiment, it connects the first refrigerant passage (36b) and the fourth refrigerant passage (36c), and is a through-hole through which low-pressure refrigerant drawn into the compressor (15) of the refrigerant circuit (30) flows. The second passage (62) The flow path switching unit according to any one of claims 1 to 3, wherein in the first embodiment, it communicates with the fourth refrigerant flow path (36c), and in the second embodiment, it communicates with the third refrigerant flow path (36d), and the outer surface of the valve body (60) is recessed in shape.

8. The flow path switching unit according to claim 7, wherein a second sealing portion (34d, 34c) is integrally formed on one of the periphery of the third refrigerant flow path (36d) and the fourth refrigerant flow path (36c) on the inner surface of the hollow portion (31A), and on the periphery of the first passage (61) on the outer surface of the valve body (60), and is in contact with the other.

9. The flow path switching unit according to any one of claims 1 to 3, wherein the casing (31) has a plurality of divided bodies (32A) that combine with each other to form the hollow portion (31A), and a metal outer shell (33) that covers the outside of the plurality of divided bodies (32A).

10. The flow path switching unit according to claim 9, further comprising a pipe (B) inserted into the first refrigerant flow path (36b) formed in the divided body (32A), wherein a third seal portion (37) is formed in the portion of the first refrigerant flow path (36b) that is in contact with the pipe (B).

Images