Heat source unit

Abstract

We provide a heat source unit that can be miniaturized and cost-effective. [Solution] A heat source unit connected to a utilization unit 12 via a connecting pipe 13, comprising a flow path switching unit 18 having a valve body 60 with first passages 61, 62 through which refrigerant flows, and a casing 32 in which the valve body 60 is rotatably housed and a first refrigerant flow path 36d through which refrigerant flows, and a controller 26 that controls the rotation of the valve body 60, wherein the connecting pipe 13 is connected to the first refrigerant flow path 36b, and the controller 26 controls the rotation of the valve body 60 to a first state in which the outer surface 60a of the valve body 60, which does not have the first passages 61, 62, is blocked from the first refrigerant flow path 36d, and a second state in which the first passages 61, 62 are connected to the first refrigerant flow path 36d.

Description

Technical Field

[0001] This disclosure relates to a heat source unit.

Background Art

[0002] Some air conditioners that adjust the indoor temperature and humidity include an outdoor unit (heat source unit) and an indoor unit (usage unit). The outdoor unit houses a compressor, a four-way switching valve, an outdoor heat exchanger, a shut-off valve, etc., and the indoor unit houses an indoor heat exchanger. These devices are connected by refrigerant pipes to form a refrigerant circuit.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Many devices such as a compressor, a four-way switching valve, an outdoor heat exchanger, and a shut-off valve are housed in the outdoor unit, and furthermore, since these are connected by refrigerant pipes, it is difficult to miniaturize and reduce costs. An object of this disclosure is to provide a heat source unit capable of miniaturization and cost reduction.

Means for Solving the Problems

[0005] (1) The heat source unit of this disclosure is a heat source unit connected to a usage unit via a communication pipe, a valve body in which a first passage through which refrigerant flows is formed, and a casing in which the valve body is rotatably housed and a first refrigerant flow path through which refrigerant flows is formed, and has a flow path switching unit, a controller for controlling the rotation of the valve body, and is provided with, the communication pipe is connected to the first refrigerant flow path, The controller controls the rotation of the valve body to alternate between a first state in which the outer surface of the valve body, which is not connected to the first passage, blocks the first refrigerant flow path, and a second state in which the first passage is connected to the first refrigerant flow path.

[0006] With the above configuration, the valve body housed in the casing of the flow path switching unit can be used to close the first refrigerant flow path to which the connecting pipe is connected, effectively allowing the flow path switching unit to be used as a shut-off valve. As a result, the shut-off valve and the refrigerant pipe connected to the shut-off valve can be eliminated or reduced, enabling miniaturization and cost reduction of the heat source unit.

[0007] (2) The heat source unit of (1) is provided with a pressing means for pressing the outer surface of the valve body against the periphery of the first refrigerant flow path in the first state.

[0008] With the above configuration, the outer surface of the valve body can be pressed against the periphery of the first refrigerant flow path to reliably close the first refrigerant flow path.

[0009] (3) In the heat source unit of (2) above, the pressing means is the refrigerant that leaked between the outer surface of the valve body and the inner surface of the casing in the second state.

[0010] With the above configuration, the leaked refrigerant can be used to press the valve body against the periphery of the first refrigerant flow path.

[0011] (4) In any one of the heat source units described in (1) to (3) above, a second refrigerant channel and a third refrigerant channel through which a refrigerant flows are formed in the casing, In the second state, the controller connects the first refrigerant flow path and the second refrigerant flow path, or the first refrigerant flow path and the third refrigerant flow path, through the first passage.

[0012] According to the above configuration, a valve (such as a three-way valve) capable of switching and connecting at least three refrigerant flow paths can be made to function as a shut-off valve.

[0013] (5) In the heat source unit of (4) above, a fourth refrigerant flow path through which refrigerant flows is formed in the casing. A second passage through which refrigerant flows is formed in the valve body. In the second state, the controller causes the second passage to connect the fourth refrigerant flow path and the third refrigerant flow path, or the fourth refrigerant flow path and the second refrigerant flow path.

[0014] According to the above configuration, a valve (such as a four-way switching valve) that can switch and connect at least four refrigerant flow paths can function as a shut-off valve.

[0015] (6) In any one of the heat source units of (1) to (5) above, the valve body and the casing are made of synthetic resin. The flow path switching unit has a second metal casing that covers the outside of the casing.

[0016] According to the above configuration, by forming the valve body and the casing from synthetic resin, weight reduction and the formation of the first passage and the first refrigerant flow path can be easily achieved, and by providing the second metal casing, the pressure resistance of the synthetic resin casing can be supplemented. [[ID=二十一]]

Brief Description of the Drawings

[0017] [[ID=二十五]] [[ID=二十六]] [Figure 1] [[ID=二十七]]It is a schematic diagram showing a refrigerant circuit of a refrigeration cycle apparatus including a flow path switching unit according to a first embodiment of the present disclosure. [[ID=二十八]] [[ID=二十九]] [Figure 2] [[ID=三十]]It is a perspective view of the flow path switching unit. [[ID=三十一]] [[ID=三十二]] [Figure 3] [[ID=三十三]]It is an exploded perspective view of the flow path switching unit. [[ID=三十四]] [[ID=三十五]] [Figure 4] [[ID=三十六]]It is a perspective view of a divided body of the inner casing of the flow path switching unit. [[ID=三十七]] [[ID=三十八]] [Figure 5] [[ID=三十九]]It is a perspective view of the valve body of the flow path switching unit. [[ID=四十]] [[ID=四十一]] [Figure 6] [[ID=四十二]]It is a cross-sectional view of the flow path switching unit. [[ID=四十三]] [[ID=四十四]] [Figure 7]It is a cross-sectional view for explaining the operation of the flow path switching unit in the first aspect. [Figure 8] It is a cross-sectional view for explaining the operation of the flow path switching unit in the second aspect. [Figure 9] It is a cross-sectional view for explaining the operation of the flow path switching unit in the third aspect. [Figure 10] It is a perspective view showing the valve body of the flow path switching unit according to the second embodiment. [Figure 11] It is a perspective view of the flow path switching unit according to the third embodiment. [Figure 12] It is a cross-sectional view of the flow path switching unit according to the third embodiment.

Mode for Carrying Out the Invention

[0018] 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 unit according to the 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 the present embodiment is an air conditioner. As shown in FIG. 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 connection pipes 13 and 14, respectively. The refrigerant circuit 30 is formed by the outdoor unit 11, the indoor unit 12, and the connection pipes 13 and 14. Note that the refrigeration cycle device 10 is not limited to an air conditioner, and may be a refrigerator, a freezer, a water heater, a ventilation device, or the like.

[0019] (Configuration of Refrigerant Circuit 30) 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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 port D of the four-way switching valve 18 via the gas side connecting pipe 13.

[0024] 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.

[0025] The four-way switching valve 18 in this embodiment functions as a shut-off valve that closes off the flow of refrigerant to the gas-side connecting pipe 13. Details of this will be described later.

[0026] 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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] (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 and a valve body 60. 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.

[0031] 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 inner surface of the hollow portion 31A substantially constitutes the inner surface of the inner casing 31. 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 those described above.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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 13 are connected to each of ports A to D.

[0037] 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 13 are connected, may be flared.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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. As shown in Figure 1, the drive unit 64 is operated by the controller 26 of the air conditioner 10 and drives the valve body 60 according to the operating state of the air conditioner 10. Specifically, the drive unit 64 is controlled to switch the valve body 60 between the first, second, and third modes, which will be described later.

[0046] The controller 26 includes a processor and memory, etc. The processor is, for example, a CPU (Central Processing Unit). However, the processor may also be a GPU (Graphics Processing Unit). The processor may also be an ASIC (Application Specific Integrated Circuit) or a programmable logic device such as a gate array or FPGA (Field Programmable Gate Array). The ASIC or programmable logic device is configured to execute processing similar to the control program. The memory includes volatile memory such as SRAM (Static Random Access Memory) and DRAM (Dynamic Random Access Memory), and non-volatile memory such as flash memory, hard disk, and ROM (Read Only Memory). The non-volatile memory stores the control program, which is a computer program, and control data. The controller 26 performs various functions by having the processor execute the control program.

[0047] (Specific structure of valve body 60) Figure 5 shows 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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°.

[0052] 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.

[0053] (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. Figure 9 is a cross-sectional view illustrating the operation of the flow path switching unit in the third 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. These first and second modes are the modes of the valve body 60 used when the air conditioner 10 is in operation. In this embodiment, the valve body 60 is switched to a third mode (see Figure 9) when the air conditioner 10 is not in operation, for example, when transporting, installing, removing, or replacing the air conditioner 10.

[0054] 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.

[0055] 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.

[0056] The valve body 60 may be restricted from rotating so that it can be 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.

[0057] 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.

[0058] 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.

[0059] 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. 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] Therefore, leakage from the end face 32A1 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 parts 32A of the inner casing 32 are molded using a mold.

[0076] (Closure of the flow path by the valve body 60) The four-way switching valve 18 in this embodiment functions as a shut-off valve that blocks the flow of refrigerant between the outdoor unit 11 and the indoor unit 12. Specifically, the four-way switching valve 18 functions as a shut-off valve by switching the valve body 60 to the third configuration shown in Figure 9.

[0077] In the third embodiment, the valve body 60 is positioned at a rotational position between the first and second embodiments. As a result, the refrigerant flow path 36d is blocked by the outer surface 60a of the valve body 60. Therefore, as shown in Figure 1, the refrigerant flow path 36d and the connecting pipe 13 connected to port D are closed, and the flow of refrigerant (gas refrigerant) between the indoor unit 12 and the outdoor unit 11 is interrupted. In other words, the flow of refrigerant (gas refrigerant) between the compressor 15 and the indoor heat exchanger 21 is interrupted.

[0078] In the third embodiment, the seal portion 34d formed around the refrigerant flow path 36d is in contact with the outer surface 60a of the valve body 60 as a whole. As a result, leakage of refrigerant from the refrigerant flow path 36d into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A is suppressed. Conversely, flow of refrigerant between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A into the refrigerant flow path 36d is suppressed.

[0079] When the air conditioner 10 is operating in cooling or heating mode, the valve body 60 takes on either the first or second mode, so that the space between the outer surface 60a and the inner surface of the recess 62 of the valve body 60 (excluding the through hole 61) and the inner surface of the hollow section 31A is filled with high-pressure refrigerant. When the valve body 60 is switched from the first or second mode to the third mode, the high-pressure refrigerant in the hollow section 31A applies high pressure to areas other than the outer surface 60a of the valve body 60 that closes the refrigerant flow path 36d. As a result, the outer surface 60a of the valve body 60 is pressed against the seal section 34d formed around the refrigerant flow path 36d on the inner surface of the hollow section 31A, and the sealing performance of the seal section 34d is enhanced. Therefore, the high-pressure refrigerant flowing into the four-way switching valve 18, which leaks into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A, constitutes a pressing means that presses the outer surface 60a of the valve body 60 against the periphery of the refrigerant flow path 36d (seal portion 34d).

[0080] When the valve body 60 is in the first mode, low-pressure refrigerant flows through the refrigerant passage 36d. Therefore, when the valve body 60 is switched from the first mode to the third mode, the refrigerant passage 36d is closed by the valve body 60 while the refrigerant pressure in the refrigerant passage 36d is low. As a result, a higher refrigerant pressure is applied to all parts of the valve body 60 except the outer surface 60a that closes the refrigerant passage 36d, and the valve body 60 is pressed more strongly against the seal portion 34d. This improves the sealing performance of the seal portion 34d.

[0081] In this embodiment, the refrigerant flow path 36d and the refrigerant flow path 36c are arranged rotationally symmetrically with respect to the rotation axis C2 of the valve body 60. Furthermore, the valve body 60 is formed symmetrically in plane with respect to the plane passing through the rotation axis C2. Therefore, the outer surface 60a of the valve body 60 blocks both the refrigerant flow path 36d and the refrigerant flow path 36c. Consequently, when the valve body 60 is switched to the third mode, the refrigerant flow path 36c and the refrigerant piping 53 connected to port C are closed, and the flow of refrigerant between the compressor 15 and the outdoor heat exchanger 16 is interrupted. Therefore, in this embodiment, the valve body 60 of the four-way switching valve 18 interrupts the flow of refrigerant between the compressor 15 and the outdoor heat exchanger 16 and the indoor heat exchanger 21.

[0082] The four-way diverter valve 18 is controlled by the controller 26. Therefore, the operation of using the four-way diverter valve 18 as a shut-off valve (the operation of switching the valve body 60 to the third mode) is also performed automatically by the controller 26. If the valve body 60 were to be manually switched to the third mode, it would be difficult to position the valve body 60 at the appropriate rotational position between the first mode and the second mode, and there is a possibility that the accuracy of the operation may vary depending on the operator. In this embodiment, the valve body 60 of the four-way diverter valve 18 is rotationally driven by a drive unit 64 with an adjustable rotation angle under the control of the controller 26, so that the valve body 60 can be positioned at the correct rotational position not only for the first and second modes but also for the third mode, thereby blocking the refrigerant flow path 36d.

[0083] The four-way switching valve 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 10 is a perspective view showing the valve body of a flow path switching unit according to a 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 11 is a perspective view of the flow path switching unit according to the third embodiment. Figure 12 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 13 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 on the outer surface 60a of the valve body 60. In this case, the tips of the sealing portions 34a to 34d contact the inner surface of the hollow portion 31A, thereby suppressing leakage of refrigerant into the gap between the outer surface 60a of the valve body 60 and the inner surface of the hollow portion 31A. 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] The sealing portions 34a to 34d may be constructed separately from the inner casing 32 and the valve body 60. In this case, the sealing portion can be constructed by forming an annular groove on the inner surface of the hollow portion 31A or on the outer surface 60a of the valve body 60 and inserting an annular sealing member into this groove.

[0095] 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.

[0096] 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 also have other shapes such as a cone shape.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] The function of the flow path switching unit as a shut-off valve as described in the above embodiment can also be applied to the liquid-side shut-off valve 23. For example, a flow path switching unit that functions as a liquid-side shut-off valve can be configured to include a valve body in which a refrigerant passage is formed, and a casing that rotatably houses the valve body. The valve body can be rotated by the control of a controller to switch between a first state in which the outer surface of the valve body blocks the refrigerant flow path between the expansion valve 17 and the indoor heat exchanger 21, and a second state in which the refrigerant flow path between the expansion valve 17 and the indoor heat exchanger 21 is connected to the passage of the valve body.

[0101] [Effects of the Embodiment] (1) The heat source unit 11 of the above embodiment is a heat source unit connected to the utilization unit 12 via a connecting pipe 13, and comprises a flow path switching unit 18 having a valve body 60 in which a first passage (for example, a through hole 61 or a recess 62) through which a refrigerant flows is formed, and a casing (for example, an inner casing 32) in which the valve body 60 is rotatably housed and a first refrigerant flow path (for example, a refrigerant flow path 36d) is formed, and a controller 26 that controls the rotation of the valve body 60. The connecting pipe 13 is connected to the first refrigerant flow path 36d. The controller 26 controls the rotation of the valve body 60 to a first state (the third embodiment described above) in which the outer surface 60a of the valve body 60, through which the first passages 61, 62 are not formed, blocks the first refrigerant flow path 36d, and a second state (the first or second embodiment described above) in which the first passages 61, 62 are in communication with the first refrigerant flow path 36d.

[0102] With this configuration, the valve body 60 housed in the casing 32 of the flow path switching unit 18 can be used to close the first refrigerant flow path 36d to which the connecting pipe 13 is connected, effectively allowing the flow path switching unit 18 to be used as a shut-off valve. As a result, the shut-off valve and the refrigerant piping connected to it can be eliminated or reduced, enabling miniaturization and cost reduction of the heat source unit 11.

[0103] (2) The heat source unit described in (1) above includes a pressing means that presses the outer surface 60a of the valve body 60 against the periphery of the first refrigerant flow path 36d in the first state. With this configuration, the outer surface 60a of the valve body 60 can be pressed against the periphery of the first refrigerant flow path 36d (specifically, the sealing portion 34d) to reliably close the first refrigerant flow path 36d.

[0104] (3) In the heat source unit described in (2), the pressing means is the refrigerant that has leaked between the outer surface 60a of the valve body 60 and the inner surface of the casing 32 (the inner surface of the hollow portion 31A) in the second state. With this configuration, the leaked refrigerant can be used to press the valve body 60 against the periphery of the first refrigerant flow path 36d.

[0105] (4) In any one of the heat source units described in (1) to (3) above, a second refrigerant flow path (e.g., refrigerant flow path 36a) and a third refrigerant flow path (e.g., refrigerant flow path 36b) are formed in the casing 32 through which the refrigerant flows. In the second state, the controller 26 connects the first refrigerant flow path 36d with the second refrigerant flow path 36a, or the first refrigerant flow path 36d with the third refrigerant flow path 36b, through the first passages 61 and 62.

[0106] With this configuration, a valve (such as a three-way valve) that can switch and connect at least three refrigerant flow paths can be used as a shut-off valve.

[0107] (5) In the heat source unit described in (4), a fourth refrigerant passage (for example, a refrigerant passage 36c) through which the refrigerant flows is formed in the casing 32, and a second passage (for example, a through hole 61 or a recess 62) through which the refrigerant flows is formed in the valve body 60. In the second state, the controller 26 connects the fourth refrigerant passage 36c and the third refrigerant passage 36b, or the fourth refrigerant passage 36c and the second refrigerant passage 36a, through the second passages 61, 62.

[0108] With this configuration, a valve (such as a four-way switching valve) that can switch and connect at least four refrigerant flow paths can be used as a shut-off valve.

[0109] (6) In any one of the heat source units described in (1) to (5) above, the valve body 60 and the casing 32 are made of synthetic resin. The flow path switching unit 18 has a second metal casing (e.g., outer casing 33) that covers the outside of the casing 32.

[0110] With this configuration, by forming the valve body 60 and casing 32 from synthetic resin, weight reduction and the formation of the first passages 61, 62 and the first refrigerant flow path 36d can be easily achieved, and the pressure resistance of the synthetic resin casing can be supplemented by providing a second metal casing 33.

[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] 11: Outdoor unit (heat source unit) 12: Indoor unit (usable unit) 13: Connecting piping 18: Four-way switching valve (flow path switching unit) 26: Controller 32: Inner casing (casing) 33: Outer casing (second casing) 36a: Refrigerant flow path (second refrigerant flow path) 36b: Refrigerant flow path (Third refrigerant flow path) 36c: Refrigerant flow path (4th refrigerant flow path) 36d: Refrigerant flow path (first refrigerant flow path) 60: Valve body 60a: Outer surface 61: Through hole (1st passage, 2nd passage) 62: Recess (First passage, Second passage)

Claims

1. A heat source unit connected to a utilization unit (12) via a connecting pipe (13), A valve body (60) having a first passage (61, 62) through which the refrigerant flows, and A flow path switching unit (18) having a casing (32) in which the valve body (60) is rotatably housed and a first refrigerant flow path (36d) through which the refrigerant flows is formed, The system includes a controller (26) that controls the rotation of the valve body (60), The connecting pipe (13) is connected to the first refrigerant flow path (36d), The controller (26) controls the rotation of the valve body (60) to alternate between a first state in which the outer surface (60a) of the valve body (60) where the first passages (61, 62) are not formed blocks the first refrigerant flow path (36d), and a second state in which the first passages (61, 62) are opened to communicate with the first refrigerant flow path (36d). In the first state, the valve body (60) is provided with a pressing means for pressing its outer surface (60a) against the periphery of the first refrigerant flow path (36d), A heat source unit in which the pressing means is the refrigerant that has leaked between the outer surface (60a) of the valve body (60) and the inner surface of the casing (32) in the second state.

2. A heat source unit connected to a utilization unit (12) via a connecting pipe (13), A valve body (60) having a first passage (61, 62) and a second passage (61, 62) through which the refrigerant flows, and A flow path switching unit (18) having a casing (32) in which the valve body (60) is rotatably housed and which has a first refrigerant flow path (36d), a second refrigerant flow path (36a), a third refrigerant flow path (36b), and a fourth refrigerant flow path (36c) through which the refrigerant flows, The system includes a controller (26) that controls the rotation of the valve body (60), The connecting pipe (13) is connected to the first refrigerant flow path (36d), The controller (26) controls the rotation of the valve body (60) to alternate between a first state in which the outer surface (60a) of the valve body (60) where the first passages (61, 62) are not formed blocks the first refrigerant flow path (36d), and a second state in which the first passages (61, 62) are opened to communicate with the first refrigerant flow path (36d). The controller (26) is a heat source unit that, in the second state, connects the first refrigerant flow path (36d) and the second refrigerant flow path (36a), or the first refrigerant flow path (36d) and the third refrigerant flow path (36b) through the first passages (61, 62), and connects the fourth refrigerant flow path (36c) and the third refrigerant flow path (36b), or the fourth refrigerant flow path (36c) and the second refrigerant flow path (36a) through the second passages (61, 62).

3. A heat source unit connected to a utilization unit (12) via a connecting pipe (13), Compressor (15) and A valve body (60) having a first passage (61, 62) through which the refrigerant flows, and A flow path switching unit (18) having a casing (32) in which the valve body (60) is rotatably housed and which has a first refrigerant flow path (36d), a second refrigerant flow path (36a), and a third refrigerant flow path (36b) formed therein, The system includes a controller (26) that controls the rotation of the valve body (60), The connecting pipe (13) is connected to the first refrigerant flow path (36d), The compressor (15) is connected to the second refrigerant passage (36a) and the third refrigerant passage (36b) via refrigerant piping (51, 52). The controller (26) is a heat source unit that controls the rotation of the valve body (60) to a first state in which the outer surface (60a) of the valve body (60), which does not have the first passages (61, 62) formed thereon, blocks the first refrigerant flow path (36d), and a second state in which the first refrigerant flow path (36d) and the second refrigerant flow path (36a), or the first refrigerant flow path (36d) and the third refrigerant flow path (36b), are connected by the first passages (61, 62).

4. The heat source unit according to claim 2 or 3, further comprising a pressing means for pressing the outer surface (60a) of the valve body (60) against the periphery of the first refrigerant flow path (36d) in the first state.

5. A second refrigerant passage (36a) and a third refrigerant passage (36b) are formed in the casing (32) through which the refrigerant flows. The heat source unit according to claim 1, wherein the controller (26) in the second state connects the first refrigerant flow path (36d) and the second refrigerant flow path (36a), or the first refrigerant flow path (36d) and the third refrigerant flow path (36b) by the first passage (61, 62).

6. The valve body (60) and the casing (32) are made of synthetic resin. The heat source unit according to any one of claims 1 to 3, wherein the flow path switching unit (18) has a second metal casing (33) that covers the outside of the casing (32).

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