Branch pipe and refrigeration device
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- DAIKIN INDUSTRIES LTD
- Filing Date
- 2025-09-22
- Publication Date
- 2026-08-06
Smart Images
Figure JP2025033331_06082026_PF_FP_ABST
Abstract
Description
Manifold pipe and refrigeration device
[0001] The present disclosure relates to a manifold pipe and a refrigeration device.
[0002] Conventionally, a plate-type refrigerant pipe formed by bonding stainless steel plates and connecting a joint pipe perpendicularly to the plate surface is known (see Patent Document 1).
[0003] Japanese Patent Application Laid-Open No. 2021-071269
[0004] When forming a connection portion for connecting a joint pipe, the plate-type refrigerant pipe requires a burring process, so the processing difficulty is high. Therefore, it is difficult to manufacture a manifold pipe that branches the flow of refrigerant.
[0005] An object of the present disclosure is to obtain a stainless steel manifold pipe by simple processing.
[0006] (1) The manifold pipe of the present disclosure connects a first pipe, a second pipe, and a third pipe, and branches the fluid flowing through the first pipe into the second pipe and the third pipe. The manifold pipe includes a stainless steel first plate-like member having a first surface and a stainless steel second plate-like member having a second surface disposed opposite to the first surface. The manifold pipe body is composed of a joint portion that joins the first plate-like member and the second plate-like member, a flow path formed between the first surface and the second surface, and at an end in the flow direction of the fluid in the flow path, a first opening, a second opening, and a third opening formed by the first plate-like member and the second plate-like member and communicating with the first pipe, the second pipe, and the third pipe, respectively.
[0007] The manifold pipe of the present disclosure can obtain a stainless steel manifold pipe by performing simple processing on a stainless steel steel plate.
[0008] (2) The branch pipe of the present disclosure according to (1) further comprises: a first pipe fitting having a first joint portion at one end in the axial direction that can be connected to the first pipe and the other end in the axial direction that is connected to the first opening; a second pipe fitting having a second joint portion at one end in the axial direction that can be connected to the second pipe and the other end in the axial direction that is connected to the second opening; and a third pipe fitting having a third joint portion at one end in the axial direction that can be connected to the third pipe and the other end in the axial direction that is connected to the third opening, wherein the joint portion includes a branch portion formed between the second opening and the third opening, and preferably the length of the branch portion in the outflow direction of the fluid flowing through the second opening and the third opening is greater than the insertion depth of the second pipe fitting at the second opening and the insertion depth of the third pipe fitting at the third opening.
[0009] The branch pipe with the above configuration can ensure pressure resistance by making the length of the branch section larger than the insertion depth of the second and third pipe fittings. Furthermore, the branch pipe of this disclosure can reliably straighten the fluid flowing from the first pipe to the second and third pipes by making the length of the branch section larger than the insertion depth of the second and third pipe fittings.
[0010] (3) In the branch pipe of the present disclosure, it is preferable that the distance between the second opening and the third opening is greater than the thickness of the branch section.
[0011] The branch pipe with the above configuration ensures sufficient space for inserting the second pipe joint and the third pipe joint at the second and third openings.
[0012] (4) In any of the embodiments of (1) to (3) of the present disclosure, the branch pipe body preferably further comprises a sealing portion that seals the gap between the outer surface of the first pipe joint and the first opening, the gap between the outer surface of the second pipe joint and the second opening, and the gap between the outer surface of the third pipe joint and the third opening.
[0013] The branch pipe with the above configuration can be made of stainless steel by applying simple processing to a stainless steel plate.
[0014] (5) In the branch pipe according to the embodiment of (4) of the present disclosure, the sealing portion preferably includes a brazing layer connecting the branch pipe body with the first pipe joint, the second pipe joint, and the third pipe joint.
[0015] In the branch pipe configuration described above, the brazing layer connecting the branch pipe body and each pipe joint can suppress fluid leakage from the gap between the branch pipe body and each pipe joint.
[0016] (6) In a branch pipe according to the embodiment of (4) or (5) of the present disclosure, the sealing portion preferably includes an end plate located at at least one of the following: the axial end of the first opening of the branch pipe body, the axial end of the second opening of the branch pipe body, and the axial end of the third opening of the branch pipe body.
[0017] The branch pipe with the above configuration, by including an end plate in the sealing portion, reduces the amount of brazing material used to seal the gaps between each of the first to third openings and each pipe joint, and the end plate also suppresses fluid leakage from the gaps between the branch pipe body and each pipe joint.
[0018] (7) In the branch pipe according to the embodiment of (5) of the present disclosure, the sealing portion preferably includes an inclusion disposed in at least one of the gaps between the outer surface of the first pipe joint and the first opening, the gap between the outer surface of the second pipe joint and the second opening, and the gap between the outer surface of the third pipe joint and the third opening.
[0019] The branch pipe of this disclosure has a sealing portion that includes inclusions other than brazing material, thereby reducing the gap between each of the first to third openings and each pipe joint. This reduces the amount of brazing material used to seal the gap and also suppresses fluid leakage from the gap between the branch pipe body and each pipe joint.
[0020] (8) In the branch pipe according to the embodiment of (5) of the present disclosure, it is preferable that at least one of the first pipe joint, the second pipe joint, and the third pipe joint has a bulge that bulges toward the gap.
[0021] The branch pipe of this disclosure can reduce the gap between each of the first to third openings and each pipe joint by providing a bulge that protrudes toward the joint in at least one of the first to third pipe joints, thereby reducing the amount of brazing material used to seal the gap and suppressing fluid leakage from the gap between the branch pipe body and each pipe joint.
[0022] (9) In the branch pipe according to the embodiment of (5) of the present disclosure, the branch pipe body further includes a third plate-shaped member, wherein at the joint, the first surface and the second surface are joined via the third plate-shaped member, and the third plate-shaped member preferably has a protruding portion that protrudes from the joint into at least one of the first opening, the second opening, and the third opening.
[0023] The branch pipe of this disclosure reduces the gap between each of the first to third openings and each pipe joint by providing an overhang portion of the third plate-shaped member in the sealing portion, thereby reducing the amount of brazing material used to seal the gap and suppressing fluid leakage from the gap between the branch pipe body and each pipe joint.
[0024] (10) In a branch pipe according to the embodiment of (5) of the present disclosure, at least one of the first opening, the second opening, and the third opening preferably includes a machined portion, and the machined portion, when viewed from the axial direction, has an inflection point where the change in the tangential direction is discontinuous.
[0025] The branch pipe of this disclosure can reduce the gap between each of the first to third openings and each pipe joint by providing a machined section, thereby reducing the amount of brazing material used to seal the gap and suppressing fluid leakage from the gap between the branch pipe body and each pipe joint.
[0026] (11) In any of the embodiments of (1) to (10) of the present disclosure, the first pipe, the second pipe, and the third pipe are preferably refrigerant pipes through which a single refrigerant consisting of carbon dioxide or a mixed refrigerant containing carbon dioxide flows.
[0027] The branch pipe of this disclosure can be used in refrigerant piping for single refrigerants consisting of carbon dioxide, which is at a higher pressure than conventional refrigerants, or for mixed refrigerants containing carbon dioxide.
[0028] (12) The refrigeration apparatus of the present disclosure comprises the branch pipe in any of the embodiments of (1) to (11) above.
[0029] The refrigeration apparatus of this disclosure uses branch pipes obtained by simple processing of stainless steel plates, and allows for the simple construction of a refrigeration apparatus including a refrigerant circuit that operates at a higher pressure than conventional systems.
[0030] Figure 1 is a schematic diagram showing a refrigeration apparatus according to one embodiment of the present disclosure. Figure 2 is a schematic perspective view showing a branch pipe according to one embodiment of the present disclosure. Figure 3 is a schematic cross-sectional view showing a branch pipe according to one embodiment of the present disclosure. Figure 4 is an explanatory diagram of a branch pipe according to the first embodiment. Figure 5 is an explanatory diagram of a branch pipe according to the second embodiment. Figure 6 is an explanatory diagram of a branch pipe according to the third embodiment. Figure 7A is an explanatory diagram of a branch pipe according to the fourth embodiment. Figure 7B is an explanatory diagram of a branch pipe according to the fourth embodiment. Figure 8A is an explanatory diagram of a branch pipe according to the fifth embodiment. Figure 8B is an explanatory diagram of a branch pipe according to the fifth embodiment.
[0031] The branch pipes and refrigeration systems having such branch pipes described herein will be described in detail below with reference to the attached drawings. However, this disclosure is not limited to these examples, and is intended to include all modifications within the meaning and scope of the equivalents of the claims, as indicated by the claims.
[0032] [Overall Configuration of Refrigeration System] Figure 1 is a schematic diagram showing a refrigeration system according to one embodiment of the present disclosure. The refrigeration system 100 shown in this embodiment is an air conditioning system that adjusts the temperature and humidity of an air-conditioned room by a vapor compression type refrigeration cycle. The refrigeration system 100 comprises a plurality of indoor units 101 (two in this embodiment) installed inside the room and an outdoor unit 102 installed outside. The indoor units 101 and the outdoor unit 102 are connected to each other by refrigerant piping 110. The indoor units 101 include a first indoor unit 101 (hereinafter also referred to as the first indoor unit 101A) and a second indoor unit 101 (hereinafter also referred to as the second indoor unit 101B). Although this embodiment illustrates a refrigeration system 100 equipped with two indoor units 101, the refrigeration system 100 of the present disclosure may be configured to have three or more indoor units 101.
[0033] The refrigeration system 100 includes a refrigerant circuit 103 that performs a vapor compression type refrigeration cycle. The refrigerant circuit 103 includes a plurality of component parts and refrigerant piping 110 that connects the plurality of component parts. The refrigerant piping 110 includes the branch pipe 10 of this disclosure. The configuration of the branch pipe 10 will be described in detail later.
[0034] The refrigerant circuit 103 includes multiple components such as a compressor 104 that compresses the refrigerant to produce high-temperature, high-pressure gaseous refrigerant, multiple indoor heat exchangers 105, an expansion valve 106 that reduces the pressure of the refrigerant, an outdoor heat exchanger 107, an accumulator 108, and a four-way switching valve 109, all of which are connected by refrigerant piping 110.
[0035] The refrigeration system 100 of this disclosure uses a single refrigerant consisting of carbon dioxide or a mixed refrigerant containing carbon dioxide (a so-called natural refrigerant) as the refrigerant. The refrigerant flowing through the refrigerant circuit 103 is at a pressure of 4.0 MPa or higher (for example, about 8 to 14 MPa). Therefore, the refrigerant piping 110 and branch pipes 10 used in the refrigeration system 100 have strength capable of withstanding a pressure of 4.0 MPa or higher. The refrigerant piping 110 and branch pipes 10 used in the refrigeration system 100 are made of stainless steel and have higher pressure resistance strength compared to, for example, refrigerant piping and branch pipes used in refrigerant circuits using conventional refrigerants (for example, R32, R410A, etc.).
[0036] The compressor 104 compresses low-pressure gaseous refrigerant and discharges high-pressure gaseous refrigerant. The compressor 104 has an inlet or inlet section 104a and a discharge port or discharge section 104b. Low-pressure gaseous refrigerant is drawn in from the inlet section 104a. High-pressure gaseous refrigerant is discharged from the discharge section 104b in the direction of arrow A. Various types of compressors, such as a scroll compressor, can be used as the compressor 104. The compressor 104 is housed in the casing 102a of the outdoor unit 102. The accumulator 108 is provided in the refrigerant piping 110 on the inlet side of the compressor 104.
[0037] The indoor heat exchanger 105 is installed in the indoor unit 101 and performs heat exchange between the refrigerant and the indoor air. For example, the indoor heat exchanger 105 can be a cross-fin type fin-and-tube heat exchanger or a microchannel type heat exchanger. The indoor fan 121 is installed near the indoor heat exchanger 105. The indoor fan 121 blows indoor air to the indoor heat exchanger 105 and sends conditioned air into the room.
[0038] The expansion valve 106 is installed in the refrigerant piping 110 between the outdoor heat exchanger 107 and the indoor heat exchanger 105. The expansion valve 106 expands the refrigerant passing through it and reduces the pressure to a predetermined level. The expansion valve 106 in this embodiment is an electronic expansion valve.
[0039] The outdoor heat exchanger 107 performs heat exchange between the refrigerant and the outdoor air. The outdoor heat exchanger 107 can be, for example, a cross-fin type fin-and-tube heat exchanger or a microchannel type heat exchanger. The outdoor fan 122 is installed near the outdoor heat exchanger 107. The outdoor fan 122 blows outdoor air to the outdoor heat exchanger 107.
[0040] The refrigerant piping 110 is equipped with a four-way switching valve 109, a gas shut-off valve 123, and a liquid shut-off valve 124 for switching the refrigerant flow path. The refrigeration system 100 can switch between cooling and heating operation by reversing the flow of refrigerant by switching the four-way switching valve 109, and supplying the refrigerant discharged from the compressor 104 to the outdoor heat exchanger 107 and the indoor heat exchanger 105.
[0041] The gas shut-off valve 123 and the liquid shut-off valve 124 open or close the refrigerant path. Opening and closing are performed, for example, manually. The gas shut-off valve 123 and the liquid shut-off valve 124 are closed, for example, when the refrigeration system 100 is installed, to prevent the refrigerant sealed in the outdoor unit 102 from leaking to the outside. On the other hand, the gas shut-off valve 123 and the liquid shut-off valve 124 are open when the refrigeration system 100 is in use.
[0042] During heating operation of the refrigeration system 100, the four-way switching valve 109 is switched as shown by the solid line, causing the refrigerant to flow in the direction indicated by the solid arrow. As a result, the high-pressure gaseous refrigerant discharged from the compressor 104 in the direction of arrow A passes through the four-way switching valve 109, then through the open gas shut-off valve 123, and enters the indoor heat exchanger 105. The high-pressure gaseous refrigerant dissipates heat in the indoor heat exchanger 105 as it becomes high-pressure liquid refrigerant. The high-pressure liquid refrigerant reaches the expansion valve 106 via the open liquid shut-off valve 124, where it is depressurized. The depressurized refrigerant reaches the outdoor heat exchanger 107, where it absorbs heat and becomes low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant is drawn into the compressor 104 via the four-way switching valve 109 and the accumulator 108. During heating operation, the indoor heat exchanger 105 functions as a heat radiator, and the outdoor heat exchanger 107 functions as a heat absorber.
[0043] On the other hand, during cooling operation, the flow of the refrigerant is reversed by switching the four-way switching valve 109 as shown by the dotted line, causing the refrigerant to flow in the direction indicated by the dotted arrow. As a result, the high-pressure gaseous refrigerant discharged from the compressor 104 in the direction of arrow A passes through the four-way switching valve 109 and enters the outdoor heat exchanger 107. The high-pressure gaseous refrigerant dissipates heat in the process of becoming high-pressure liquid refrigerant in the outdoor heat exchanger 107. The high-pressure liquid refrigerant reaches the expansion valve 106, where it is depressurized. The depressurized refrigerant passes through the open liquid shut-off valve 124 to the indoor heat exchanger 105, where it absorbs heat and becomes low-pressure gaseous refrigerant. The low-pressure gaseous refrigerant is drawn into the compressor 104 via the open gas shut-off valve 123, the four-way switching valve 109, and the accumulator 108. During cooling operation, the indoor heat exchanger 105 functions as a heat absorber, and the outdoor heat exchanger 107 functions as a heat radiator.
[0044] [Regarding the refrigerant piping] As shown in FIG. 1, in the refrigeration device 100 of the present disclosure, the refrigerant piping 110 includes a first piping 111, a second piping 112, and a third piping 113. The refrigerant piping 110 further includes a branch pipe 10 that connects the first piping 111, the second piping 112, and the third piping 113. The first piping 111, the second piping 112, the third piping 113, and the branch pipe 10 form part of the refrigerant circuit 103. The first piping 111, the second piping 112, and the third piping 113 are made of copper, and the branch pipe 10 is made of stainless steel. Note that in the refrigerant piping 110 of the present disclosure, the first piping 111, the second piping 112, and the third piping 113 may be made of stainless steel, for example, and are not limited to being made of copper.
[0045] The first piping 111 includes the refrigerant piping 110 disposed inside the outdoor unit 102 and the refrigerant piping 110 that connects the outdoor unit 102 and the branch pipe 10. The first piping 111 includes a first liquid refrigerant piping 111L and a first gas refrigerant piping 111G. Liquid refrigerant flows through the first liquid refrigerant piping 111L, and gas refrigerant flows through the first gas refrigerant piping 111G.
[0046] The second piping 112 is the refrigerant piping 110 that connects the first indoor unit 101A and the branch pipe 10. The second piping 112 includes a second liquid refrigerant piping 112L and a second gas refrigerant piping 112G. Liquid refrigerant flows through the second liquid refrigerant piping 112L, and gas refrigerant flows through the second gas refrigerant piping 112G.
[0047] The third piping 113 is the refrigerant piping 110 that connects the second indoor unit 101B and the branch pipe 10. The third piping 113 includes a third liquid refrigerant piping 113L and a third gas refrigerant piping 113G. Liquid refrigerant flows through the third liquid refrigerant piping 113L, and gas refrigerant flows through the third gas refrigerant piping 113G.
[0048] [Regarding the branch pipe] As shown in FIG. 1, the refrigeration device 100 of the present disclosure includes two branch pipes 10 (referred to as the first branch pipe 10X and the second branch pipe 10Y). Note that the refrigeration device 100 of the present disclosure may be configured to include three or more branch pipes 10 according to the number of indoor units 101. In the present embodiment, the branch pipe 10 is used for connecting the indoor unit 101 and the outdoor unit 102, but the use of the branch pipe 10 of the present disclosure is not limited thereto, and it may be used, for example, in the branch portion of the internal piping of the outdoor unit 102. Note that in the present embodiment, the branch pipe 10 is used for flowing a refrigerant, which is an example of a fluid, but it may also be used for flowing a fluid other than the refrigerant (such as water, nitrogen gas, etc.).
[0049] The first branch pipe 10X connects the first liquid refrigerant pipe 111L, the second liquid refrigerant pipe 112L, and the third liquid refrigerant pipe 113L. The first branch pipe 10X branches the liquid refrigerant flowing in from the first liquid refrigerant pipe 111L and discharges it to the second liquid refrigerant pipe 112L and the third liquid refrigerant pipe 113L. Further, the first branch pipe 10X combines the liquid refrigerant flowing in from the second liquid refrigerant pipe 112L and the third liquid refrigerant pipe 113L and discharges it to the first liquid refrigerant pipe 111L.
[0050] The second branch pipe 10Y connects the first gas refrigerant pipe 111G, the second gas refrigerant pipe 112G, and the third gas refrigerant pipe 113G. The second branch pipe 10Y branches the gas refrigerant flowing in from the first gas refrigerant pipe 111G and discharges it to the second gas refrigerant pipe 112G and the third gas refrigerant pipe 113G. Further, the second branch pipe 10Y combines the gas refrigerant flowing in from the second gas refrigerant pipe 112G and the third gas refrigerant pipe 113G and discharges it to the first gas refrigerant pipe 111G.
[0051] FIG. 2 is a perspective schematic view schematically showing a branch pipe according to an embodiment of the present disclosure. FIG. 3 is a cross-sectional schematic view showing a branch pipe according to an embodiment of the present disclosure. As shown in FIGS. 2 and 3, the branch pipe 10 includes a branch pipe body 20, a first pipe joint 31, a second pipe joint 32, and a third pipe joint 33. Note that in FIG. 2, for the sake of convenience of explanation, the illustration of some parts (such as the sealing portion 28, the first joint portion 34, the second joint portion 35, the third joint portion 36, etc., which will be described later) is omitted.
[0052] As shown in Figure 2, the branch pipe body 20 is composed of a first plate-shaped member 21 and a second plate-shaped member 22. The first plate-shaped member 21 and the second plate-shaped member 22 are members manufactured into a predetermined shape by press-forming stainless steel plates. The material of the first plate-shaped member 21 and the second plate-shaped member 22 is, for example, SUS304L. As will be explained later, the first plate-shaped member 21 and the second plate-shaped member 22 may be subjected to further machining other than press-forming (for example, grinding, polishing, etc.) (see Figures 8A and 8B).
[0053] The first plate-shaped member 21 has a first surface 21a. The first surface 21a is the surface that faces inward towards the branch pipe body 20 when the first plate-shaped member 21 is assembled as the branch pipe body 20. The second plate-shaped member 22 has a second surface 22a. The second surface 22a is the surface that faces inward towards the branch pipe body 20 when the second plate-shaped member 22 is assembled as the branch pipe body 20. The first plate-shaped member 21 and the second plate-shaped member 22 are arranged with their first surface 21a and second surface 22a facing each other.
[0054] The branch pipe body 20 is further composed of a joint 24. The branch pipe body 20 is composed of a first plate-shaped member 21 and a second plate-shaped member 22 joined by the joint 24. In this embodiment, the joint 24 is a layer made of brazing material (sheet brazing) formed between the first surface 21a and the second surface 22a. In the branch pipe body 20 of this embodiment, the joint 24 is the part where the first surface 21a and the second surface 22a are brazed together, but it may also be a part (bead) where the outer surface (end face) of the first plate-shaped member 21 perpendicular to the first surface 21a and the outer surface (end face) of the second plate-shaped member 22 perpendicular to the second surface 22a are welded (TIG welding, laser welding, etc.).
[0055] The branch pipe body 20 further comprises a flow path 25 formed between a first surface 21a and a second surface 22a. The flow path 25 is a flow path (space) through which a fluid (in this embodiment, a refrigerant (liquid refrigerant or gaseous refrigerant)) flows. The branch pipe body 20 has a plurality of openings 26. The plurality of openings 26 include a first opening 26a, a second opening 26b, and a third opening 26c formed by the first plate-shaped member 21 and the second plate-shaped member 22 at the ends in the flow direction of the refrigerant in the flow path 25. The first opening 26a, the second opening 26b, and the third opening 26c are opened in directions that do not intersect with the first surface 21a and the second surface 22a. The branch pipe 10 of this embodiment has three openings 26 (first opening 26a, second opening 26b, and third opening 26c). The first opening 26a, the second opening 26b, and the third opening 26c are each formed inside the cylindrical portion formed by the first plate-like member 21 and the second plate-like member 22. In the branch pipe 10 of this disclosure, there may be three or more openings 26, for example, four.
[0056] As described above, the branch pipe 10 of this disclosure can be easily manufactured by joining a first plate-shaped member 21 and a second plate-shaped member 22, which are made by press-forming (bending) stainless steel plates. In other words, the branch pipe 10 can be manufactured by simple processing such as press-forming (bending) and welding.
[0057] The branch pipe body 20 further includes a branch section 27. The branch section 27 is the part that branches the refrigerant flowing into the flow path 25 from the first opening 26a to the second opening 26b side and the third opening 26c side. The branch section 27 is also the part (merging section) that merges the refrigerant flowing into the flow path 25 from the second opening 26b and the third opening 26c and flows it to the first opening 26a side. In the branch pipe 10 of this embodiment, there is one branch section 27, but two or more may be provided depending on the number of openings 26.
[0058] The first pipe joint 31 has one end 31a inserted into the first opening 26a. The second pipe joint 32 has one end 32a inserted into the second opening 26b. The third pipe joint 33 has one end 33a inserted into the third opening 26c. The first pipe joint 31, the second pipe joint 32, and the third pipe joint 33 are brazed in a furnace to the branch pipe body 20.
[0059] In the branch pipe 10, leakage of refrigerant from the gaps (hereinafter referred to as gap Z) between the outer circumferential surface 31c on one end 31a of the first pipe joint 31 and the first opening 26a, between the outer circumferential surface 32c on one end 32a of the second pipe joint 32 and the second opening 26b, and between the outer circumferential surface 33c on one end 33a of the third pipe joint 33 and the third opening 26c is a problem. For this reason, the branch pipe 10 is further provided with a sealing portion 28 that seals the gap Z. The form of the sealing portion 28 will be described in detail later.
[0060] The branch pipe 10 further comprises a first joint section 34 provided at the other end 31b of the first pipe joint 31, a second joint section 35 provided at the other end 32b of the second pipe joint 32, and a third joint section 36 provided at the other end 33b of the third pipe joint 33. The first joint section 34, the second joint section 35, and the third joint section 36 are made of copper. The copper first joint section 34, the second joint section 35, and the third joint section 36 can be connected to the first pipe 111, the second pipe 112, and the third pipe 113 by brazing at the site. In the branch pipe 10 of this disclosure, the first pipe joint 31, the second pipe joint 32, and the third pipe joint 33 may be made of materials other than copper and are not limited to being made of copper.
[0061] The branch pipe 10 is formed as part of the refrigerant piping 110 by connecting the first joint 34 to the first pipe 111, the second joint 35 to the second pipe 112, and the third joint 36 to the third pipe 113.
[0062] [Regarding the setting of the dimensions of each part of the branch pipe] As shown in Figures 2 and 3, the branch pipe 10 of this embodiment includes a branch section 27 formed between the second opening 26b and the third opening 26c. As shown in Figure 3, in the branch pipe 10 of this embodiment, the forming length L1 of the branch section 27 in the axial direction of the second opening 26b and the third opening 26c is set to be longer than the insertion allowance L2 of the second pipe joint 32 at the second opening 26b and the insertion allowance L3 of the third pipe joint 33 at the third opening 26c (L1 > L2, L1 > L3).
[0063] By having this configuration, the branch pipe 10 of this embodiment can ensure pressure resistance that can withstand the use of high-pressure refrigerants, and can also reliably straighten the flow of refrigerant from the first pipe 111 to the second pipe 112 and the third pipe 113.
[0064] As shown in Figures 2 and 3, in the branch pipe 10 of this embodiment, the separation distance W between the second opening 26b and the third opening 26c is set to be greater than the thickness D of the branch section 27 (W > D). The thickness D of the branch section 27 is the sum of the thicknesses of the first plate-like member 21, the second plate-like member 22, and the joint 24.
[0065] In this embodiment, the branch pipe 10 can be configured in such a way that it is possible to secure an insertion depth L2 for the second pipe joint 32 at the second opening 26b, and an insertion depth L3 for the third pipe joint 33 at the third opening 26c. As a result, the branch pipe 10 in this embodiment can be configured to withstand the pressure required for the use of high-pressure natural refrigerants.
[0066] [Regarding the sealing portion] In the branch pipe 10 of this disclosure, the brazing layer S connecting the first to third pipe joints 31 to 33 and the branch pipe body 20 can be used as a sealing portion 28. The brazing layer S is a layer made of brazing material. However, when using the brazing layer S as a sealing portion 28, it is necessary to supply an appropriate amount of brazing material to the gap Z, and if the amount of brazing material is not appropriate, shrinkage cavities may occur in the brazing layer S. Since shrinkage cavities are areas where refrigerant may leak, it is preferable that the branch pipe 10 of this disclosure adopts a configuration that suppresses refrigerant leakage from shrinkage cavities in the brazing layer S. For this reason, the branch pipe 10 of this disclosure is configured based on one of the following ideas: 1) sealing the gap Z using a material other than brazing material while allowing the occurrence of shrinkage cavities in the brazing layer S, or 2) reducing the gap Z and suppressing the occurrence of shrinkage cavities by suppressing the amount of brazing material used in the brazing layer S.
[0067] [Branch pipe according to the first embodiment] Figure 4 is an explanatory diagram of a branch pipe according to the first embodiment. Figure 4 shows a first embodiment of the branch pipe 10 of the present disclosure. In this description, the branch pipe 10 according to the first embodiment will also be referred to as branch pipe 10A. As shown in Figure 4, the branch pipe 10A according to the first embodiment is characterized by having an end plate 51. The upper part of Figure 4 shows the branch pipe body 20 before the end plate 51 is installed, with the first opening 26a and the first pipe joint 31 viewed from the axial direction. The lower part of Figure 4 shows the branch pipe body 20 after the end plate 51 is installed, with the first opening 26a and the first pipe joint 31 viewed from the axial direction. As shown in Figure 4, the branch pipe 10A has an end plate 51 that seals the gap Z between the first opening 26a and the first pipe joint 31. The end plate 51 is part of the sealing portion 28. The branch pipe 10A suppresses leakage of fluid (refrigerant) from the gap Z by sealing the gap Z with the end plate 51. Furthermore, branch pipe 10A allows for the occurrence of shrinkage cavities in the brazing material. For this reason, in branch pipe 10A, the gap Z does not need to be completely filled with brazing material. Furthermore, in branch pipe 10A, the gap Z may be completely filled with brazing material.
[0068] As shown in Figure 4, the end plate 51 is positioned at the axial end of the first opening 26a of the branch pipe body 20. The end plate 51 is made of stainless steel. The end plate 51 is furnace brazed to the axial end of the first opening 26a of the branch pipe body 20 and to the first pipe joint 31.
[0069] Figure 4 illustrates only the end plate 51 positioned at the first opening 26a, and the end plates 51 positioned at the second opening 26b and the third opening 26c are not shown. In the branch pipe 10A, the end plates 51 are similarly positioned at the axial end of the second opening 26b of the branch pipe body 20 and at the axial end of the third opening 26c of the branch pipe body 20.
[0070] In the branch pipe 10A, the end plate 51 does not have to be placed in all of the first opening 26a, the second opening 26b, and the third opening 26c, but may be placed in one or more of the first opening 26a, the second opening 26b, and the third opening 26c. In other words, the branch pipe 10A includes an end plate 51 placed in at least one of the axial ends of the first opening 26a, the axial end of the second opening 26b, and the axial end of the third opening 26c.
[0071] In the branch pipe 10, if the gaps Z between each opening 26a to 26c and each pipe joint 31 to 33 are all filled with brazing material, the amount of brazing material required will increase, and the brazing process will become more time-consuming (i.e., brazing will take longer). In the branch pipe 10A according to the first embodiment, the gaps Z are sealed by the end plate 51, so there is no need to fill the gaps Z with brazing material. Therefore, the branch pipe 10A having the end plate 51 can reduce the amount of brazing material used in the sealing portion 28 and reduce the brazing process. In addition, by reducing shrinkage cavities in the brazing material layer S, leakage of refrigerant from the gaps Z can be suppressed.
[0072] [Branch pipe according to the second embodiment] Figure 5 is an explanatory diagram of a branch pipe according to the second embodiment. Figure 5 shows a second embodiment of the branch pipe 10 of the present disclosure. In this description, the branch pipe 10 according to the second embodiment will also be referred to as branch pipe 10B. As shown in Figure 5, the branch pipe 10B according to the second embodiment is characterized by having an inclusion 52. Figure 5 shows the first opening 26a and the first pipe joint 31 of the branch pipe 10B as viewed from the axial direction. As shown in Figure 5, the branch pipe 10B has a sealing portion 28 that fills the gap Z between the first opening 26a and the first pipe joint 31. In the branch pipe 10B, the sealing portion 28 includes a brazing material that fills the gap Z and an inclusion 52. The inclusion 52 is part of the sealing portion 28. The branch pipe 10B can reduce the gap Z by the inclusion 52 and suppress the amount of brazing material used, thereby reducing shrinkage cavities in the brazing material layer S, and thereby suppressing refrigerant leakage from the gap Z. In this embodiment, the intervening material 52 is a stainless steel wire. However, the intervening material 52 constituting the branch pipe 10B in this embodiment is not limited to a stainless steel wire.
[0073] Figure 5 illustrates only the intervening material 52 placed in the first opening 26a, and the intervening material 52 placed in the second opening 26b and the third opening 26c is not shown. In the branch pipe 10B of this embodiment, the intervening material 52 is similarly placed in the second opening 26b and the third opening 26c. In the branch pipe 10B, the intervening material 52 does not have to be placed in all of the first opening 26a, the second opening 26b, and the third opening 26c, and may be placed in one or more of the first opening 26a, the second opening 26b, and the third opening 26c. In other words, the branch pipe 10B includes an intervening material 52 placed in at least one of the first opening 26a, the second opening 26b, and the third opening 26c.
[0074] The first plate-shaped member 21 and the second plate-shaped member 22 are brazed in a furnace with an inclusion 52 placed in the region (gap Z) surrounded by the first plate-shaped member 21, the second plate-shaped member 22, and the respective pipe joints 31 to 33. In the branch pipe 10B according to the second embodiment, a portion of the gap Z is filled with the inclusion 52, and the remaining gap Z is filled with brazing material. In the branch pipe 10B with this configuration, the amount of brazing material required to fill the gap Z can be reduced by the volume of the inclusion 52. As a result, the branch pipe 10B can reduce the amount of brazing material used in the sealing portion 28 and reduce the effort required for brazing. In addition, shrinkage cavities in the brazing material layer S can be reduced, thereby suppressing refrigerant leakage from the gap Z.
[0075] In the branch pipe 10B of this embodiment, it is preferable that the inclusion 52 placed in the first opening 26a is connected to one of the inclusions 52 placed in the second opening 26b and one of the inclusions 52 placed in the third opening 26c. Furthermore, in the branch pipe 10B of this embodiment, it is preferable that the other inclusion 52 placed in the second opening 26b is connected to the other inclusion 52 placed in the third opening 26c. By using inclusions 52 with such a configuration, the number of inclusions 52 can be reduced, thereby reducing the brazing effort. The amount of shrinkage voids in the brazing material layer S can be reduced, thereby suppressing refrigerant leakage from the gap Z.
[0076] [Branch pipe according to the third embodiment] Figure 6 is an explanatory diagram of a branch pipe according to the third embodiment. Figure 6 shows a third embodiment of the branch pipe 10 of the present disclosure. In this description, the branch pipe 10 according to the third embodiment will also be referred to as branch pipe 10C. As shown in Figure 6, the branch pipe 10C according to the third embodiment is characterized in that the pipe joint has a bulging portion. Figure 6 shows the first opening 26a and the first pipe joint 31 of the branch pipe 10C as viewed from the axial direction. As shown in Figure 6, the branch pipe 10C has a sealing portion 28 that fills the gap Z between the first opening 26a and the first pipe joint 31.
[0077] In the branch pipe 10C, the first pipe joint 31 has a bulge portion 53. The bulge portion 53 is a part of the first pipe joint 31 that bulges outwards toward the gap Z. The bulge portion 53 bulges radially outward from a virtual circle C (see Figure 6) which is assumed to be a perfect circle when the cross-sectional shape of the first pipe joint 31 perpendicular to the axial direction is assumed to be a perfect circle. In other words, the first pipe joint 31 having the bulge portion 53 does not have a perfect circle when the cross-sectional shape of the cross-sectional shape perpendicular to the axial direction is not a perfect circle. By reducing the gap Z with the bulge portion 53 in the branch pipe 10C and suppressing the amount of brazing material used, shrinkage cavities in the brazing material layer S can be reduced, thereby suppressing refrigerant leakage from the gap Z.
[0078] Figure 6 illustrates only the bulge 53 of the first pipe joint 31, and the bulges 53 provided on the second pipe joint 32 and the third pipe joint 33 are not shown. In the branch pipe 10C, the second pipe joint 32 and the third pipe joint 33 have bulges 53 similar to those of the first pipe joint 31. The branch pipe 10C does not need to have bulges 53 in all of the first pipe joint 31, the second pipe joint 32, and the third pipe joint 33; it may be configured so that one or more of the first pipe joint 31, the second pipe joint 32, and the third pipe joint 33 have bulges 53. In other words, the branch pipe 10C includes a bulge 53 located in at least one of the first pipe joint 31, the second pipe joint 32, and the third pipe joint 33.
[0079] In the third embodiment, the branch pipe 10C reduces the internal volume of the gap Z by providing a bulge 53. As a result, the branch pipe 10C can reduce the amount of brazing material used in the sealing portion 28 and reduce the effort required for brazing. In addition, it can reduce sink marks in the brazing material layer S, thereby suppressing refrigerant leakage from the gap Z.
[0080] [Branch pipe according to the fourth embodiment] Figures 7A and 7B are explanatory diagrams of a branch pipe according to the fourth embodiment. Figure 7A shows a fourth embodiment of the branch pipe 10 of the present disclosure. In this description, the branch pipe 10 according to the fourth embodiment will also be referred to as branch pipe 10D. As shown in Figure 7A, the branch pipe 10D according to the fourth embodiment is characterized in that the branch pipe body 20 is composed of a third plate-shaped member 23. Figure 7A shows the first opening 26a and the first pipe joint 31 of the branch pipe 10D as viewed from the axial direction. As shown in Figure 7A, the branch pipe 10D has a sealing portion 28 that fills the gap Z between the first opening 26a and the first pipe joint 31.
[0081] In the branch pipe 10D, the branch pipe body 20 has a third plate-shaped member 23. The third plate-shaped member 23 is a stainless steel plate (flat plate). The third plate-shaped member 23 has a third surface 23a facing the first surface 21a of the first plate-shaped member 21, and a fourth surface 23b facing the second surface 22a of the second plate-shaped member 22. The third surface 23a is joined to the first surface 21a by a joint 24. The fourth surface 23b is joined to the second surface 22a by a joint 24. In the branch pipe 10D, the first plate-shaped member 21 and the second plate-shaped member 22 are joined via the third plate-shaped member 23 by a joint 24.
[0082] In the branch pipe 10D, the third plate-shaped member 23 is provided with an overhang portion 54 that protrudes from the joint portion 24 into the first opening 26a. By reducing the gap Z with the overhang portion 54, the branch pipe 10D can reduce the amount of brazing material used, thereby reducing shrinkage cavities in the brazing material layer S, and thus suppressing refrigerant leakage from the gap Z.
[0083] Figure 7A illustrates only the protruding portion 54 located in the first opening 26a, and the protruding portions 54 located in the second opening 26b and the third opening 26c are not shown. In the branch pipe 10D, the third plate-shaped member 23 has a protruding portion 54 that protrudes from the joint 24 to the second opening 26b, and a protruding portion 54 that protrudes from the joint 24 to the third opening 26c. In the branch pipe 10D, the protruding portion 54 does not have to be located in all of the first opening 26a, the second opening 26b, and the third opening 26c, and may be located in one or more of the first opening 26a, the second opening 26b, and the third opening 26c. In other words, the branch pipe 10D includes a protruding portion 54 located in at least one of the first opening 26a, the second opening 26b, and the third opening 26c.
[0084] In the fourth embodiment, the branch pipe 10D reduces the internal volume of the gap Z by providing an overhang portion 54. As a result, the branch pipe 10D can reduce the amount of brazing material used in the sealing portion 28 and reduce the effort required for brazing. Furthermore, it can reduce sink marks in the brazing material layer S, thereby suppressing refrigerant leakage from the gap Z.
[0085] The branch pipe 10D may also have the configuration shown in Figure 7B. Figure 7B shows a modified example of the branch pipe 10D according to the fourth embodiment. As shown in Figure 7B, the modified example of the branch pipe 10D according to the fourth embodiment is characterized in that the branch pipe body 20 is composed of a plurality (two in this embodiment) third plate-shaped members 23 (third plate-shaped members 23X, 23Y).
[0086] As shown in Figure 7B, in a modified example of the branch pipe 10D, the branch pipe body 20 has two third plate-shaped members 23. The third surface 23a of one of the third plate-shaped members 23X is joined to the first surface 21a by a joint 24. The fourth surface 23b of one of the third plate-shaped members 23X is joined to the third surface 23a of the other third plate-shaped member 23Y by a joint 24. The fourth surface 23b of the other third plate-shaped member 23Y is joined to the second surface 22a by a joint 24. In a modified example of the branch pipe 10D, the first plate-shaped member 21 and the second plate-shaped member 22 are joined via two third plate-shaped members 23X and 23Y by a joint 24.
[0087] A modified version of the branch pipe 10D according to the fourth embodiment has two third plate-shaped members 23, which allows the proportion of the volume of the protruding portion 54 to the internal volume of the gap Z to be increased, thereby reducing the internal volume of the gap Z more significantly compared to the branch pipe 10D shown in Figure 7A. Therefore, with this modified version of the branch pipe 10D, the amount of brazing material used in the sealing portion 28 can be reduced, and the effort required for brazing can be reduced. In addition, shrinkage cavities in the brazing material layer S can be reduced, thereby suppressing refrigerant leakage from the gap Z. The number of third plate-shaped members 23 constituting the modified version of the branch pipe 10D may be three or more.
[0088] [Branch pipe according to the fifth embodiment] Figures 8A and 8B are explanatory diagrams of a branch pipe according to the fifth embodiment. Figure 8A shows the fifth embodiment of the branch pipe 10 of the present disclosure. In this description, the branch pipe 10 according to the fifth embodiment will also be referred to as branch pipe 10E. As shown in Figure 8A, the branch pipe 10E according to the fifth embodiment is characterized in that the branch pipe body 20 has a machined portion 55. Figure 8A shows the first opening 26a and the first pipe joint 31 of the branch pipe 10E as viewed from the axial direction. As shown in Figure 8A, the branch pipe 10E has a sealing portion 28 that fills the gap Z between the first opening 26a and the first pipe joint 31.
[0089] In the branch pipe 10E, the first plate-shaped member 21 and the second plate-shaped member 22 have machined portions 55. In the branch pipe body 20 shown in Figure 8A, the machined portions 55 are formed on the flat portions of the first plate-shaped member 21 and the second plate-shaped member 22.
[0090] The machined portion 55 is a part of the first plate-shaped member 21 and the second plate-shaped member 22, which are formed by press-forming or the like from stainless steel plates (flat plates), that has been further machined (cutting in this embodiment) to change the shape of a part of the first surface 21a and the second surface 22a. In this embodiment, the machined portion 55 is a part of the first plate-shaped member 21 and the second plate-shaped member 22 that has been cut and a part of it removed to change the shape of the first surface 21a and the second surface 22a. Note that the machined portion 55 may also be a part that has been partially removed by machining other than cutting (for example, grinding, polishing, etc.).
[0091] In the branch pipe 10E, when the first opening 26a is viewed from the axial direction, the machined portion 55 becomes a new first surface 21a of the first plate-shaped member 21 and a new second surface 22a of the second plate-shaped member 22. In the branch pipe 10E, the branch pipe body 20 is constructed by joining the first surface 21a (machined portion 55) and the second surface 22a (machined portion 55) by a joint portion 24.
[0092] In the absence of the machined portion 55 (see, for example, the upper diagram in Figure 4), the shape of the first opening 26a when viewed from the axial direction is a shape in which the tangential direction change is continuous (first shape). On the other hand, as shown in Figure 8A, in a branch pipe 10E having a machined portion 55, the shape of the first opening 26a (machined portion 55) when viewed from the axial direction is a shape having an inflection point P1 where the tangential direction change is discontinuous (second shape). A branch pipe 10E including this (second shape) can reduce the internal volume of the gap Z compared to a branch pipe 10 including the (first shape). By reducing the gap Z with the machined portion 55 and suppressing the amount of brazing material used, the branch pipe 10E can reduce sink marks in the brazing material layer S, thereby suppressing refrigerant leakage from the gap Z.
[0093] Figure 8A illustrates only the machined portion 55 provided around the first opening 26a, and the machined portions 55 provided around the second opening 26b and the third opening 26c are not shown. The branch pipe 10E also has machined portions 55 around the second opening 26b and the third opening 26c, similar to those around the first opening 26a. In the branch pipe 10E, the machined portions 55 do not have to be provided in all of the first opening 26a, the second opening 26b, and the third opening 26c, and the configuration may be such that the machined portions 55 are provided in one or more of the first opening 26a, the second opening 26b, and the third opening 26c. In other words, the branch pipe 10E includes a machined portion 55 provided in at least one of the first opening 26a, the second opening 26b, and the third opening 26c.
[0094] In the fifth embodiment, the branch pipe 10E reduces the internal volume of the gap Z by providing a machined portion 55. As a result, the branch pipe 10E can reduce the amount of brazing material used in the sealing portion 28 and reduce the effort required for brazing. In addition, it can reduce sink marks in the brazing material layer S, thereby suppressing refrigerant leakage from the gap Z.
[0095] The branch pipe 10E may also have the configuration shown in Figure 8B. Figure 8B shows a modified example of the branch pipe 10E according to the fifth embodiment. As shown in Figure 8B, the modified example of the branch pipe 10E according to the fifth embodiment is characterized in that the machined portion 55 is formed on the arc (curved) portion of the first plate-shaped member 21 and the second plate-shaped member 22.
[0096] As shown in Figure 8B, in a modified example of the branch pipe 10E according to the fifth embodiment, the machined portion 55 is formed in an arc (curved) portion. In the modified branch pipe 10E, the machined portion 55 is a part of the first surface 21a of the first plate-like member 21 and a part of the second surface 22a of the second plate-like member 22.
[0097] In the modified branch pipe 10E, the machined portion 55 when the first opening 26a is viewed from the axial direction has a shape (third shape) having an inflection point P2 where the tangential change is discontinuous. Compared to the branch pipe 10 containing the (first shape), the internal volume of the gap Z can be reduced. Therefore, the modified branch pipe 10E can reduce the amount of brazing material used in the sealing portion 28 and reduce the effort required for brazing. In addition, shrinkage cavities in the brazing material layer S can be reduced, thereby suppressing refrigerant leakage from the gap Z.
[0098] [Effects of the Embodiment] (1) The branch pipe 10 of the above embodiment is a branch pipe that connects the first pipe 111, the second pipe 112, and the third pipe 113, and comprises a branch pipe body 20 comprising a first plate-shaped member 21 made of stainless steel having a first surface 21a, and a second plate-shaped member 22 made of stainless steel having a second surface 22a that is arranged opposite to the first surface 21a. The branch pipe body 20 comprises a joint portion 24 that joins the first plate-shaped member 21 and the second plate-shaped member 22, a flow path 25 formed between the first surface 21a and the second surface 22a, and the flow path 25 comprises a first opening 26a, a second opening 26b, and a third opening 26c formed by the first plate-shaped member 21 and the second plate-shaped member 22 at the end in the direction of refrigerant flow, which communicate with the first pipe 111, the second pipe 112, and the third pipe 113, respectively.
[0099] According to the above configuration of the branch pipe 10, a stainless steel branch pipe 10 can be obtained by applying simple processing to a stainless steel plate.
[0100] (2) The branch pipe 10 of this embodiment further comprises: a first pipe joint 31 having a first joint portion 34 that can be connected to the first pipe 111 at one end 31a in the axial direction and the other end 31b in the axial direction connected to a first opening 26a; a second pipe joint 32 having a second joint portion 35 that can be connected to the second pipe 112 at one end 32a in the axial direction and the other end 32b in the axial direction connected to a second opening 26b; and a third pipe joint 33 having a third joint portion 36 that can be connected to the third pipe 113 at one end 33a in the axial direction and the other end 33b in the axial direction connected to a third opening 26c. In the branch pipe 10, the joint 24 includes a branch section 27 formed between the second opening 26b and the third opening 26c, and the length L1 of the branch section 27 in the outflow direction of the refrigerant flowing through the second opening 26b and the third opening 26c is greater than the insertion allowance L2 of the second pipe fitting 32 at the second opening 26b and the insertion allowance L3 of the third pipe fitting 33 at the third opening 26c (L1 > L2, L1 > L3).
[0101] With the branch pipe 10 configured as described above, pressure resistance can be ensured, and the fluid (refrigerant) flowing from the first pipe 111 to the second pipe 112 and the third pipe 113 can be reliably straightened.
[0102] (3) In the branch pipe 10 of this embodiment, the separation distance W between the second opening 26b and the third opening 26c is greater than the thickness D of the branch section 27 (W > D).
[0103] With the branch pipe 10 configured as described above, insertion gaps L2 and L3 for the second pipe joint 32 and the third pipe joint 33 can be secured at the second opening 26b and the third opening 26c.
[0104] (4) The branch pipe 10 of this embodiment further includes a sealing portion 28 that seals the gap Z between the outer surface 31c of the first pipe joint 31 and the first opening 26a, the gap Z between the outer surface 32c of the second pipe joint 32 and the second opening 26b, and the gap Z between the outer surface 33c of the third pipe joint 33 and the third opening 26c.
[0105] According to the above configuration of the branch pipe 10, a stainless steel branch pipe 10 can be obtained by applying simple processing to a stainless steel plate.
[0106] (5) In the branch pipe 10 of this embodiment, the sealing portion 28 includes a brazing material layer S that connects the branch pipe body 20 with the first pipe joint 31, the second pipe joint 32, and the third pipe joint 33.
[0107] With the branch pipe 10 configured as described above, the brazing layer S connecting the branch pipe body 20 and each pipe joint 31 to 33 can suppress refrigerant leakage from the gap Z.
[0108] (6) In the branch pipe 10A of the form shown in Figure 4, the sealing portion 28 includes an end plate 51 disposed at at least one of the axial ends of the first opening 26a, the second opening 26b, and the third opening 26c.
[0109] According to the above configuration of the branch pipe 10A, by sealing the gap Z with the end plate 51, the amount of brazing material used to seal the gap Z can be reduced, and the end plate 51 can also suppress the leakage of refrigerant from the gap Z.
[0110] (7) In the branch pipe 10B of the form shown in Figure 5, the sealing portion 28 includes an inclusion 52 that is placed in at least one of the following gaps: the gap Z between the first opening 26a and the first pipe joint 31, the gap Z between the second opening 26b and the second pipe joint 32, and the gap Z between the third opening 26c and the third pipe joint 33.
[0111] According to the branch pipe 10B with the above configuration, by including inclusions 52 other than the brazing material in the sealing portion 28, the gap Z can be reduced. This suppresses the amount of brazing material used to seal the gap Z and reduces shrinkage cavities in the brazing material layer S, thereby suppressing refrigerant leakage from the gap Z.
[0112] (8) The branch pipe 10C in the configuration shown in Figure 6 has a bulge 53 formed in at least one of the first pipe joint 31, the second pipe joint 32, and the third pipe joint 33, which bulges out toward the gap Z.
[0113] With the branch pipe 10C configured as described above, the bulge portion 53 reduces the gap Z, thereby suppressing the amount of brazing material used to seal the gap Z and reducing sink marks in the brazing material layer S, which in turn suppresses refrigerant leakage from the gap Z.
[0114] (9) In the branch pipe 10D of the form shown in Figures 7A and 7B, the branch pipe body 20 further includes a third plate-shaped member 23, and at the joint 24, the first surface 21a and the second surface 22a are joined via the third plate-shaped member 23. In the branch pipe 10D, the third plate-shaped member 23 has an overhang portion 54 that protrudes from the joint 24 into at least one of the first opening 26a, the second opening 26b, and the third opening 26c.
[0115] The branch pipe 10D with the above configuration can reduce the gap Z by the protruding portion 54, thereby suppressing the amount of brazing material used to seal the gap Z and reducing shrinkage cavities in the brazing material layer S, thereby suppressing refrigerant leakage from the gap Z.
[0116] (10) In the branch pipe 10E of the form shown in Figures 8A and 8B, at least one of the first opening 26a, the second opening 26b, and the third opening 26c includes a machined portion 55 that has been cut, and the machined portion 55, when viewed from the axial direction, has inflection points P1 and P2 where the change in the tangential direction is discontinuous.
[0117] The branch pipe 10E with the above configuration can reduce the gap Z by providing a machined section 55, thereby suppressing the amount of brazing material used to seal the gap Z and reducing sink marks in the brazing material layer S, which in turn suppresses refrigerant leakage from the gap Z.
[0118] (11) In the branch pipe 10 of the above embodiment, the first pipe 111, the second pipe 112, and the third pipe 113 are refrigerant pipes 110 through which a single refrigerant consisting of carbon dioxide or a mixed refrigerant containing carbon dioxide flows.
[0119] The branch pipe 10 with the above configuration can be used in refrigerant piping 110 for a single refrigerant consisting of carbon dioxide, which is at a higher pressure than conventional refrigerants, or for a mixed refrigerant containing carbon dioxide.
[0120] (12) The refrigeration apparatus 100 of the present disclosure includes a branch pipe 10.
[0121] According to the refrigeration device 100 of this embodiment, a refrigeration device 100 including a refrigerant circuit 103 that operates at a higher pressure than conventional devices can be easily constructed by using a branch pipe 10 obtained by simply processing a stainless steel plate.
[0122] 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.
[0123] 10: Branch pipe 20: Branch pipe body 21: First plate-shaped member 21a: First surface 22: Second plate-shaped member 22a: Second surface 23: Third plate-shaped member 24: Joint 25: Flow path 26a: First opening 26b: Second opening 26c: Third opening 27: Branch section 28: Sealing section 31: First pipe joint 31a: One end 31b: Other end 32: Second pipe joint 32a: One end 32b: Other end 33: Third pipe joint 33a: One end 33b: Other end 34: First joint section 35: Second joint section 36: Third joint section 51: End plate 52: Inclusion 53 : Bulging part 54: Overhanging part 55: Machined part 100: Refrigeration device 110: Refrigerant piping 111: First piping 112: Second piping 113: Third piping S: Brazing layer Z: Gap L1: Formation length (of the branching part) L2: Insertion allowance (at the second opening) L3: Insertion allowance (at the third opening) W: Separation distance D: Thickness (of the branching part)
Claims
1. A branch pipe (10) that connects a first pipe (111), a second pipe (112), and a third pipe (113), and branches the fluid flowing through the first pipe (111) to the second pipe (112) and the third pipe (113), comprising a branch pipe body (20) comprising a first plate-shaped member (21) made of stainless steel having a first surface (21a), and a second plate-shaped member (22) made of stainless steel having a second surface (22a) positioned opposite the first surface (21a), wherein the branch pipe body (20) comprises a joint (24) that joins the first plate-shaped member (21) and the second plate-shaped member (22), and a flow path (25) formed between the first surface (21a) and the second surface (22a), A branch pipe (10) is provided with a first opening (26a), a second opening (26b), and a third opening (26c) formed by the first plate-shaped member (21) and the second plate-shaped member (22) at the end of the flow path (25) in the direction of fluid flow, and communicating with the first pipe (111), the second pipe (112), and the third pipe (113), respectively.
2. The joint (24) further comprises: a first pipe joint (31) having a first joint portion (34) at one axial end (31a) that can be connected to the first pipe (111), and the other axial end (31b) connected to the first opening (26a); a second pipe joint (32) having a second joint portion (35) at one axial end (32a) that can be connected to the second pipe (112), and the other axial end (32b) connected to the second opening (26b); and a third pipe joint (33) having a third joint portion (36) at one axial end (33a) that can be connected to the third pipe (113), and the other axial end (33b) connected to the third opening (26c), wherein the joint (24) includes a branch portion (27) formed between the second opening (26b) and the third opening (26c). The branch pipe (10) according to claim 1, wherein the length (L1) of the branch portion (27) in the outflow direction of the fluid flowing through the second opening (26b) and the third opening (26c) is greater than the insertion depth (L2) of the second pipe fitting (32) at the second opening (26b) and the insertion depth (L3) of the third pipe fitting (33) at the third opening (26c).
3. The branch pipe (10) according to claim 2, wherein the separation distance (W) between the second opening (26b) and the third opening (26c) is greater than the thickness (D) of the branch portion (27).
4. The branch pipe body (20) further comprises a sealing portion (28) that seals the gap (Z) between the outer circumferential surface (31c) of the first pipe joint (31) and the first opening (26a), the gap (Z) between the outer circumferential surface (32c) of the second pipe joint (32) and the second opening (26b), and the gap (Z) between the outer circumferential surface (33c) of the third pipe joint (33) and the third opening (26c), as described in claim 1 or claim 2.
5. The branch pipe (10) according to claim 4, wherein the sealing portion (28) includes a brazing layer (S) connecting the branch pipe body (20) with the first pipe joint (31), the second pipe joint (32), and the third pipe joint (33).
6. The branch pipe (10A) according to claim 4, wherein the sealing portion (28) includes an end plate (51) disposed at at least one of the axial ends of the first opening (26a), the second opening (26b), and the third opening (26c).
7. The branch pipe (10B) according to claim 5, wherein the sealing portion (28) includes an inclusion (52) disposed in at least one of the following: the gap (Z) between the outer circumferential surface (31c) of the first pipe joint (31) and the first opening (26a), the gap (Z) between the outer circumferential surface (32c) of the second pipe joint (32) and the second opening (26b), and the gap (Z) between the outer circumferential surface (33c) of the third pipe joint (33) and the third opening (26c).
8. The branch pipe (10C) according to claim 5, wherein at least one of the first pipe joint (31), the second pipe joint (32), and the third pipe joint (33) has a bulging portion (53) that bulges toward the gap (Z).
9. The branch pipe (10D) according to claim 5, wherein the branch pipe body (20) further includes a third plate-shaped member (23), and at the joint (24), the first surface (21a) and the second surface (22a) are joined via the third plate-shaped member (23), and the third plate-shaped member (23) has a protruding portion (54) that protrudes from the joint (24) into at least one of the first opening (26a), the second opening (26b), and the third opening (26c).
10. The branch pipe (10E) according to claim 5, wherein at least one of the first opening (26a), the second opening (26b), and the third opening (26c) includes a machined portion (55) that has been machined, and the machined portion (55), when viewed from the axial direction, has inflection points (P1, P2) where the change in the tangential direction is discontinuous.
11. The branch pipe (10) according to claim 1 or 2, wherein the first pipe (111), the second pipe (112), and the third pipe (113) are refrigerant pipes (110) through which a single refrigerant consisting of carbon dioxide or a mixed refrigerant containing carbon dioxide flows.
12. A refrigeration apparatus (100) comprising the branch pipe (10) according to claim 1 or claim 2.