Connection piping, refrigerator and connecting method for connection piping

Abstract

To suppress melting of a coating member when brazing connection piping having the coating member and other piping.SOLUTION: Connection piping (C) includes: a first pipe part (11) having a first pipe end part (15) to which a first fluid member (F1) is connected; a second pipe part (12) having one end to which the first pipe part (11) is connected and the other end to which a second fluid member (F2) is connected; and a coating member (R). The coating member (R) includes a first coating end part (R1) and a second coating end part (R2). The shortest distance L1 between the first coating end part (R1) and the first pipe end part (15) is larger than the shortest distance L2 between the first coating end part (R1) and the second coating end part (R2).SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present disclosure relates to a connecting pipe, a refrigeration device, and a method for connecting the connecting pipe.

Background Art

[0002] In an air conditioner or the like, a heat exchange function is utilized. In a device that utilizes such a heat exchange function, a pipe through which a heat exchange medium (for example, a refrigerant) flows is provided, and the evaporator section and the condenser section are connected by this pipe to form a heat medium circuit. In the heat medium circuit, the heat exchange medium circulates by a compressor or the like.

[0003] Patent Document 1 discloses a pipe for a heat exchange medium. Since the pipe through which the heat exchange medium flows forms a complex pipeline, the number of branch portions increases. In a branch portion, the pressure resistance is likely to decrease due to its structure. Therefore, in Patent Document 1, the pressure resistance of the pipe is improved by covering the pipe with a covering member as a surrounding material.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When connecting a pipe covered with a covering member, which is a surrounding material as in Patent Document 1, to another pipe by brazing to form a heat medium circuit, there is a risk that the covering member may melt due to the heat during brazing.

[0006] An object of the present disclosure is to suppress melting of the covering member when brazing a connecting pipe provided with the covering member to another pipe.

Means for Solving the Problems

[0007] The first aspect is directed to a metal connection pipe (C) disposed between a first fluid member (F1) and a second fluid member (F2) through which a fluid flows and connecting the two. The connection pipe (C) includes a first pipe portion (11) having a first pipe end portion (15) to which the first fluid member (F1) is connected, a second pipe portion (12) having one end connected to the first pipe portion (11) and the other end connected to the second fluid member (F2), and a covering member (R) covering at least a part of the second pipe portion (12). The covering member (R) has a first covering end portion (R1) which is an end portion on the first pipe portion (11) side in the axial direction of the first pipe portion (11), and a second covering end portion (R2) which is an end portion on the side opposite to the first covering end portion (R1) in the axial direction. The shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is greater than the shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2).

[0008] In the first aspect, since the shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is greater than the shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2), the first pipe end portion (15) is sufficiently separated from the covering member (R). Therefore, melting of the covering member (R) during brazing the first pipe portion (11) and the first fluid member (F1) can be suppressed.

[0009] The second aspect is the first aspect, wherein the covering member (R) covers a part of the second pipe portion (12), the second pipe portion (12) has a second pipe end portion (16) to which the second fluid member (F2) is connected, and the shortest distance L3 between the second covering end portion (R2) and the second pipe end portion (16) is greater than the shortest distance L2.

[0010] In the second aspect, since the shortest distance L3 between the second covering end portion (R2) and the second pipe end portion (16) is greater than the shortest distance L2, the second pipe end portion (16) is sufficiently separated from the covering member (R). Therefore, melting of the covering member (R) during brazing the second pipe portion (12) and the second fluid member (F2) can be suppressed.

[0011] In a third aspect, in the first or second aspect, the second pipe portion (12) has a thick-walled portion (32) and a thin-walled portion (31) having a thickness thinner than that of the thick-walled portion (32), and the thin-walled portion (31) is covered with the covering member (R).

[0012] In the third aspect, since the thin-walled portion (31) is covered with the covering member (R), the thin-walled portion (31) with low pressure resistance can be reinforced.

[0013] In a fourth aspect, in the third aspect, the first pipe portion (11) is a first metal pipe (M1) made of metal, and the second pipe portion (12) is a second metal pipe (M2) made of metal. The second metal pipe (M2) has a curved portion (60) formed in an arc shape, a first straight portion (61) extending in the axial direction from the top of the curved portion (60) and connected to the first metal pipe (M1), and second and third straight portions (62 and 63) extending from each end of the curved portion (60). The thin-walled portion (31) is formed in the curved portion (60) of the second metal pipe (M2).

[0014] In the fourth aspect, the curved portion (60) is likely to have a thinner wall thickness in the second pipe portion (12). Therefore, by covering the thin-walled portion (31) of the curved portion (60) with the covering member (R), the portion with low pressure resistance can be reinforced.

[0015] In a fifth aspect, in the third aspect, the first pipe portion (11) is a first metal pipe (M1) made of metal, and the second pipe portion (12) includes an enlarged pipe (80) made of metal and a second metal pipe (M2). One end of the enlarged pipe (80) is connected to the first metal pipe (M1) and the other end is connected to the second metal pipe (M2), and the outer diameter of the enlarged pipe (80) is larger than those of the first metal pipe (M1) and the second metal pipe (M2). The thin-walled portion (31) is formed in the enlarged pipe (80).

[0016] In the fifth aspect, the enlarged pipe (80) is likely to have a thin-walled portion formed. Therefore, by covering the thin-walled portion (31) of the enlarged pipe (80) with the covering member (R), the portion with low pressure resistance can be reinforced.

[0017] In the sixth aspect, in the third aspect, the first pipe portion (11) is a first metal pipe (M1) made of metal, and the second pipe portion (12) is a second metal pipe (M2) made of metal. The second metal pipe (M2) has a plurality of short pipe portions (71) to which each of the plurality of first metal pipes (M1) is connected, and one long pipe portion (72) that extends in a direction intersecting the direction in which the short pipe portion (71) extends and is formed continuously with the short pipe portion (71). The thin wall portion (31) is formed at the base end portion of the short pipe portion (71).

[0018] In the sixth aspect, the base end portion of the short pipe portion (71) is likely to have a reduced wall thickness. Therefore, by covering the base end portion of the short pipe portion (71) with the covering member (R), the portion with low pressure resistance can be reinforced.

[0019] In the seventh aspect, in the first or second aspect, the second pipe portion (12) has a brazed portion (33) that is brazed, and the brazed portion (33) is covered with the covering member (R).

[0020] In the seventh aspect, since the brazed portion (33) is covered with the covering member (R), the portion where the pressure resistance has been reduced by brazing can be reinforced.

[0021] In the eighth aspect, in the seventh aspect, the first pipe portion (11) is a first metal pipe (M1) made of metal, and the second pipe portion (12) includes a second metal pipe (M2), a third metal pipe (M3), and a branch pipe (10). The branch pipe (10) branches the fluid flowing through the first metal pipe (M1) into the second metal pipe (M2) and the third metal pipe (M3). Two connection portions (22, 23) are formed in the branch pipe (10) to which the second metal pipe (M2) and the third metal pipe (M3) are respectively connected and are provided adjacent to each other. The brazed portion (33) is formed between the connection portion (22) on the second metal pipe (M2) side and the connection portion (23) on the third metal pipe (M3) side.

[0022] In the eighth aspect, the brazed portion (33) formed between the connection portion (22) on the side of the second metal pipe (M2) and the connection portion (23) on the side of the third metal pipe (M3) is likely to have its pressure resistance reduced by heat treatment. Therefore, by covering the brazed portion (33) with the covering member (R), the portion with low pressure resistance can be reinforced.

[0023] The ninth aspect is, in the third aspect, the covering member (R) has a main covering portion (51) and a reinforcing portion (52) that is thicker than the main covering portion (51), and the reinforcing portion (52) is disposed at a position overlapping with the thin-walled portion (31).

[0024] In the ninth aspect, since the thin-walled portion (31) of the second pipe portion (12) and the reinforcing portion (52) of the covering member (R) overlap, the thin-walled portion (31) can be further reinforced.

[0025] The tenth aspect is, in the seventh aspect, the covering member (R) has a main covering portion (51) and a reinforcing portion (52) that is thicker than the main covering portion (51), and the reinforcing portion (52) is disposed at a position overlapping with the brazed portion (33).

[0026] In the tenth aspect, since the brazed portion (33) of the second pipe portion (12) and the reinforcing portion (52) of the covering member (R) overlap, the brazed portion (33) can be further reinforced.

[0027] The eleventh aspect is, in any one of the first to tenth aspects, the covering member (R) is made of resin.

[0028] In the eleventh aspect, since the covering member (R) is made of resin, the shape and thickness of the covering member (R) can be freely set.

[0029] The twelfth aspect is, in any one of the first to eleventh aspects, further includes a sealing member (E) that is disposed on the outer peripheral surface of the covering member (R) and suppresses the inflow of fluid between the connection pipe (C) and the covering member (R).

[0030] In the twelfth aspect, since the sealing member (E) suppresses the inflow of fluid between the connecting pipe (C) and the covering member (R), it is possible to prevent the covering member (R) from being damaged by the condensed water generated or flowing in between the connecting pipe (C) and the covering member (R).

[0031] The thirteenth aspect is any one of the first to twelfth aspects, wherein the covering member (R) covers the first pipe portion (11) and the second pipe portion (12). The first pipe portion (11) includes a large-diameter portion (41) formed in the middle portion of the first pipe portion (11) and a small-diameter portion (42) formed at an end connected to one end of the second pipe portion (12) and having an outer diameter smaller than that of the large-diameter portion (41). The small-diameter portion (42) is disposed inside the opening on one end side of the second pipe portion (12).

[0032] In the thirteenth aspect, since the small-diameter portion (42) of the first pipe portion (11) is disposed inside the opening of the second pipe portion (12), it is difficult for a step to occur at the connection portion between the first pipe portion (11) and the second pipe portion (12). Therefore, when the connecting pipe (C) thermally expands, it is possible to prevent the covering member (R) from being damaged by the step.

[0033] The fourteenth aspect is a refrigeration device including the first fluid member (F1), the second fluid member (F2), and the connecting pipe (C) according to any one of the first to twelfth aspects.

[0034] In the fourteenth aspect, it is possible to provide a refrigeration device (1) that suppresses melting of the covering member (R) of the connecting pipe (C).

[0035] Aspect 15 is directed to a method of connecting a metal connection pipe (C) disposed between and connecting a first fluid member (F1) and a second fluid member (F2) through which a fluid flows. The connection pipe (C) includes a first pipe portion (11) having a first pipe end portion (15) to which the first fluid member (F1) is connected, a second pipe portion (12) having one end connected to the first pipe portion (11) and the other end connected to the second fluid member (F2), and a covering member (R) covering at least a part of the second pipe portion (12). The covering member (R) has a first covering end portion (R1) that is an end portion on the first pipe portion (11) side in the axial direction of the first pipe portion (11), and a second covering end portion (R2) that is an end portion on the side opposite to the first covering end portion (R1) in the axial direction. The shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is greater than the shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2). The method of connecting the connection pipe (C) includes a step of disposing the connection pipe (C) between the first fluid member (F1) and the second fluid member (F2), and a step of brazing one end portion of the connection pipe (C) and one end portion of the first fluid member (F1), and brazing the other end portion of the connection pipe (C) and one end portion of the second fluid member (F2).

[0036] In Aspect 15, since the shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is greater than the shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2), the first pipe end portion (15) is sufficiently separated from the covering member (R). Therefore, melting of the covering member (R) can be suppressed in the step of brazing the pipes together.

Brief Description of the Drawings

[0037]

Figure 1

Figure 2

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Figure 14

DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. Note that the present disclosure is not limited to the embodiments shown below, and various modifications are possible without departing from the technical idea of the present disclosure. Since each drawing is for conceptually explaining the present disclosure, dimensions, ratios, or numbers may be exaggerated or simplified as necessary for easy understanding.

[0039] 《Embodiment 1》 Embodiment 1 will be described. First, the refrigeration device (1) in which the connecting pipe (C) of the present embodiment is provided will be described.

[0040] (1) Refrigeration device As shown in Fig. 1, the connection pipe (C) is provided in the refrigeration device (1). The refrigeration device (1) has a refrigerant circuit (2) filled with a refrigerant. The refrigerant corresponds to the fluid of the present disclosure. The refrigerant circuit (2) has a compressor, a radiator, a decompression mechanism, and an evaporator (not shown). The refrigerant circuit performs a vapor compression refrigeration cycle. In the refrigeration cycle, the refrigerant compressed by the compressor dissipates heat to the air in the radiator. The refrigerant that has dissipated heat is decompressed by the decompression mechanism and evaporates in the evaporator. The evaporated refrigerant is sucked into the compressor.

[0041] The refrigeration device (1) of the present embodiment is an air conditioner. The air conditioner may be a cooling-only unit, a heating-only unit, or an air conditioner that switches between cooling and heating. In this case, the air conditioner has a switching mechanism (for example, a four-way switching valve) for switching the circulation direction of the refrigerant. The refrigeration device (1) may be a water heater, a chiller unit, a cooling device for cooling the air in a room, etc. The cooling device cools the air inside a refrigerator, a freezer, a container, etc.

[0042] As shown in Fig. 1, the refrigeration device (1) of the present embodiment includes a plurality of outdoor units (3) and a plurality of indoor units (4). Specifically, the refrigeration device (1) includes an outdoor unit group (GO) composed of three outdoor units (3), a first indoor unit group (GI1) composed of three indoor units (4), and a second indoor unit group (GI2) composed of two indoor units (4). In the refrigeration device (1), the outdoor unit group (GO), the first indoor unit group (GI1), and the second indoor unit group (GI2) are connected in series in this order.

[0043] Each outdoor unit (3) has a compressor. Each outdoor unit (3) and each indoor unit (4) are connected via a communication pipe (5) to form the refrigerant circuit (2).

[0044] The communication pipe (5) has a connection pipe (C). The communication pipe (5) of the present embodiment includes, as the connection pipe (C), a first connection pipe (6), a second connection pipe (7), a third connection pipe (8), and a fourth connection pipe (9). Each connection pipe (C) connects a plurality of pipes. The first connection pipe (6), the second connection pipe (7), and the fourth connection pipe (9) connect one pipe and two pipes. The third connection pipe (8) connects one pipe and four pipes.

[0045] The first connection pipe (6) is disposed between the outdoor unit group (GO) and the first indoor unit group (GI1). The first connection pipe (6) connects a pipe extending from the third connection pipe (8), a pipe extending from the first outdoor unit (3a), and a pipe extending from the second connection pipe (7). The second connection pipe (7) connects a pipe extending from the first connection pipe (6), a pipe extending from the second outdoor unit (3b), and a pipe extending from the third outdoor unit (3c).

[0046] The third connection pipe (8) is disposed between the outdoor unit group (GO) and the second indoor unit group (GI2). The third connection pipe (8) connects a pipe extending from the first connection pipe (6), a pipe extending from the fourth connection pipe (9), and pipes extending from each of the three indoor units (4) of the first indoor unit group (GI1). The fourth connection pipe (9) connects a pipe extending from the third connection pipe (8) and pipes extending from each of the two indoor units (4) of the second indoor unit group (GI2).

[0047] (2) Connection Pipe Next, the connection pipe (C) of the present disclosure will be described. The connection pipe (C) of the present embodiment is used, for example, for the first connection pipe (6) and the second connection pipe (7) in FIG. 1. Note that the connection pipe (C) of the present embodiment may be used in locations other than the first connection pipe (6) and the second connection pipe (7) in FIG. 1.

[0048] As shown in FIG. 2, the connecting pipe (C) is disposed between the first refrigerant pipe (F1) and the second refrigerant pipe (F2). The connecting pipe (C) connects the first refrigerant pipe (F1) and the second refrigerant pipe (F2). The first refrigerant pipe (F1) and the second refrigerant pipe (F2) are pipes through which refrigerant flows. The first refrigerant pipe and the second refrigerant pipe (F2) are made of metal. The first refrigerant pipe (F1) corresponds to the first fluid member of the present disclosure. The second refrigerant pipe (F2) corresponds to the second fluid member of the present disclosure.

[0049] The connecting pipe (C) has a branch pipe (10), a first metal pipe (M1), a second metal pipe (M2), a third metal pipe (M3), and a covering member (R). The branch pipe (10), the first metal pipe (M1), the second metal pipe (M2), and the third metal pipe (M3) are made of copper or copper alloy, aluminum or aluminum alloy (metal).

[0050] (2-1) Branch pipe The branch pipe (10) branches the refrigerant flowing through the first metal pipe (M1) into the second metal pipe (M2) and the third metal pipe (M3). The branch pipe (10) has a first connection portion (21), a second connection portion (22), a third connection portion (23), and an expanded pipe portion (24). The first connection portion (21), the expanded pipe portion (24), the second connection portion (22), and the third connection portion (23) are integrally formed.

[0051] The first connection portion (21) is formed at one end (the right end in FIG. 2) of the branch pipe (10). The first connection portion (21) is formed in a straight pipe shape. The first metal pipe (M1) is connected to one end (the right end in FIG. 2) of the first connection portion (21). An expanded pipe portion (24) is formed on the other end (the left end in FIG. 2) side of the first connection portion (21).

[0052] The expanded pipe portion (24) is formed in the middle of the branch pipe (10). The inner diameter of the expanded pipe portion (24) gradually increases from one end side (the right end in FIG. 2) toward the other end side (the right end in FIG. 2). The second connection portion (22) and the third connection portion (23) are formed at the other end of the expanded pipe portion (24).

[0053] The second connecting portion (22) and the third connecting portion (23) are formed at the other end of the branch pipe (10). Each of the second connecting portion (22) and the third connecting portion (23) is formed in a straight tubular shape. The second connecting portion (22) and the third connecting portion (23) are provided adjacent to each other in the radial direction (the vertical direction in FIG. 2). An enlarged diameter portion (24) is formed at one end (the right end in FIG. 2) of the second connecting portion (22). A second metal pipe (M2) is connected to the other end (the left end in FIG. 2) of the second connecting portion (22). An enlarged diameter portion (24) is formed at one end (the right end in FIG. 2) of the third connecting portion (23). A third metal pipe (M3) is connected to the other end (the left end in FIG. 2) of the third connecting portion (23). The second connecting portion (22) and the third connecting portion (23) correspond to the connecting portions of the present disclosure.

[0054] The enlarged diameter portion (24) includes a thin wall portion (31) and a thick wall portion (32). The thickness of the thin wall portion (31) is thinner than the thickness of the thick wall portion (32). The thin wall portion (31) is a curved portion formed on one end side of the enlarged diameter portion (24). The thick wall portion (32) is a straight portion formed on the other end side of the enlarged diameter portion (24). In the present embodiment, the thickness of the pipe of the curved portion of the enlarged diameter portion (24) is thinner than the thickness of the pipe of the straight portion that is not curved. Such a thin wall portion (31) is generated in the process of manufacturing the branch pipe (10) by plastic working.

[0055] The branch pipe (10) has a brazed portion (33) brazed. The brazed portion (33) is formed between the second connecting portion (22) and the third connecting portion (23). The space formed inside the second connecting portion (22) and the space formed inside the third connecting portion (23) are blocked by the brazed portion (33).

[0056] (2-2) The first metal pipe, the second metal pipe, the third metal pipe The first metal pipe (M1) is a straight pipe extending straight. The first metal pipe (M1) is a horizontally long pipe. The cross section perpendicular to the axial direction of the first metal pipe (M1) is formed in a substantially circular shape. The outer diameter and the inner diameter of the first metal pipe (M1) are substantially constant.

[0057] The second metal pipe (M2) and the third metal pipe (M3) are the same metal pipes as the first metal pipe (M1). Therefore, the first metal pipe (M1), the second metal pipe (M2), and the third metal pipe (M3) are pipes with the same outer diameter and inner diameter as each other. The second metal pipe (M2) and the third metal pipe (M3) of the present embodiment have the same axial length. The axial lengths of the second metal pipe (M2) and the third metal pipe (M3) may be different. The first metal pipe (M1), the second metal pipe (M2), and the third metal pipe (M3) extend in the same direction as each other.

[0058] One end (the right end in FIG. 2) of the first metal pipe (M1) is connected to the first refrigerant pipe (F1), and the other end (the left end in FIG. 2) is connected to the first connection portion (21) of the branch pipe (10). The first metal pipe (M1) and the first refrigerant pipe (F1) are connected by brazing. One end (the right end in FIG. 2) of the second metal pipe (M2) is connected to the second connection portion (22) of the branch pipe (10), and the other end (the left end in FIG. 2) is connected to one of the second refrigerant pipes (F2). The second metal pipe (M2) and the upper second refrigerant pipe (F2) are connected by brazing. One end (the right end in FIG. 2) of the third metal pipe (M3) is connected to the third connection portion (23) of the branch pipe (10), and the other end (the left end in FIG. 2) is connected to the other second refrigerant pipe (F2). The third metal pipe (M3) and the lower second refrigerant pipe (F2) are connected by brazing.

[0059] The first metal tube (M1) has a large-diameter portion (41) and a small-diameter portion (42). The large-diameter portion (41) is formed in the middle part of the first metal tube (M1). In the present embodiment, the large-diameter portion (41) is the portion of the first metal tube (M1) other than the small-diameter portion (42). The small-diameter portion (42) is formed at the other end of the first metal tube (M1). The small-diameter portion (42) is a portion where the diameter of the first metal tube (M1) is reduced. The outer diameter of the small-diameter portion (42) is smaller than the outer diameter of the large-diameter portion (41). The small-diameter portion (42) is disposed inside the first connection portion (21) of the branch pipe (10). In other words, the small-diameter portion (42) is disposed inside the opening on one end side of the branch pipe (10). Therefore, the outer peripheral surface of the large-diameter portion (41) of the first metal tube (M1) and the outer peripheral surface of the first connection portion (21) of the branch pipe (10) are flush, and no step is formed between the two outer peripheral surfaces.

[0060] Similar to the first metal tube (M1), the second metal tube (M2) and the third metal tube (M3) also have a large-diameter portion (41) and a small-diameter portion (42). The small-diameter portion (42) of each of the second metal tube (M2) and the third metal tube (M3) is formed at one end of each of the second metal tube (M2) and the third metal tube (M3). The small-diameter portion (42) of the second metal tube (M2) is disposed inside the second connection portion (22) of the branch pipe (10). The small-diameter portion (42) of the third metal tube (M3) is disposed inside the third connection portion (23) of the branch pipe (10). The outer peripheral surface of the large-diameter portion (41) of the second metal tube (M2) and the outer peripheral surface of the second connection portion (22) of the branch pipe (10) are flush, and no step is formed between the two outer peripheral surfaces. The outer peripheral surface of the large-diameter portion (41) of the third metal tube (M3) and the outer peripheral surface of the third connection portion (23) of the branch pipe (10) are flush, and no step is formed between the two outer peripheral surfaces.

[0061] The connecting pipe (C) has a first pipe portion (11) and a second pipe portion (12). In the present embodiment, the first metal pipe (M1) corresponds to the first pipe portion (11), and the portion of the connecting pipe (C) other than the first pipe portion (11) corresponds to the second pipe portion (12). Specifically, in the present embodiment, the branch pipe (10), the second metal pipe (M2), and the third metal pipe (M3) correspond to the second pipe portion (12). One end portion of the first metal pipe (M1) corresponds to the first pipe end portion (15) of the present disclosure. One end (the right end in FIG. 2) of the second pipe portion (12) is connected to the first metal pipe (M1), and the other end (the left end in FIG. 2) is connected to the second refrigerant pipe (F2). The other end portions of the second metal pipe (M2) and the third metal pipe (M3) correspond to the second pipe end portion (16) of the present disclosure.

[0062] (2-3) Coating member The coating member (R) covers at least a part of the second pipe portion (12). The coating member (R) may cover all of the second pipe portion (12). The coating member (R) of the present embodiment covers the outer peripheral surfaces of a part of the first pipe portion (11) and a part of the second pipe portion (12). Specifically, the coating member (R) covers the branch pipe (10) and the vicinity of the branch pipe (10) in the connecting pipe (C). The coating member (R) covers the entire branch pipe (10), a part of the first metal pipe (M1), a part of the second metal pipe (M2), and a part of the third metal pipe (M3).

[0063] The coating member (R) is made of resin. The coating member (R) is formed by insert molding. The coating member (R) has a first coating end portion (R1) and a second coating end portion (R2). The first coating end portion (R1) is the end portion on the first metal pipe (M1) side in the axial direction of the first metal pipe (M1). The second coating end portion (R2) is the end portion on the side opposite to the first coating end portion (R1) in the axial direction of the first metal pipe (M1). Specifically, the second coating end portion (R2) is the end portion on the second metal pipe (M2) and third metal pipe (M3) side in the axial direction of the first metal pipe (M1).

[0064] The thin-walled portion (31) and the brazed portion (33) of the manifold (10) are covered with a covering member (R). The thin-walled portion (31) and the brazed portion (33) are structurally likely to have low pressure resistance. Therefore, by covering the thin-walled portion (31) and the brazed portion (33) with the covering member (R), the portion with low pressure resistance can be reinforced, and the pressure resistance of the connecting pipe (C) can be improved.

[0065] In the present embodiment, there is no step between the first connection portion (21), the second connection portion (22), and the third connection portion (23) of the manifold (10) and the metal pipes connected thereto respectively. Therefore, when the connecting pipe (C) thermally expands, even if the connecting pipe (C) expands in the extending direction of the manifold (10), there is no step at the connection portion, so the covering member (R) is less likely to be damaged.

[0066] (2-4) Relationship between the covering member and each metal pipe As shown in FIG. 2, the shortest distance L1 between the first covering end (R1) and the first pipe end (15) is greater than the shortest distance L2 between the first covering end (R1) and the second covering end (R2) (L2 < L1). Therefore, the first pipe end (15) is sufficiently separated from the covering member (R). Thus, when brazing the first metal pipe (M1) and the first refrigerant pipe (F1), it is possible to suppress the melting of the covering member (R) due to the heat of brazing.

[0067] Also, the shortest distance L3 between the second covering end (R2) and the second pipe end (16) is greater than the shortest distance L2 (L2 < L3). Therefore, the second pipe end (16) is sufficiently separated from the covering member (R). Thus, when brazing each of the second metal pipe (M2) and the third metal pipe (M3) to the second refrigerant pipe (F2), it is possible to suppress the melting of the covering member (R) due to the heat of brazing. When the axial lengths of the second metal pipe (M2) and the third metal pipe (M3) are different, the shortest distance L3 is the distance between the second pipe end (16) closer to the second covering end (R2) and the second covering end (R2).

[0068] (3) Connection method of the connecting pipe Next, the connection method of the connecting pipe (C) will be described. The connection method of the connecting pipe (C) includes an arrangement step and a brazing step. The arrangement step and the brazing step are performed in this order.

[0069] In the first step, the connecting pipe (C) is arranged between the first refrigerant pipe (F1) and the second refrigerant pipe (F2). Specifically, in the first step, after arranging the connecting pipe (C) between the first refrigerant pipe (F1) and the second refrigerant pipe (F2), the positions of the ends of each pipe are aligned so that the first refrigerant pipe (F1) and the first metal pipe (M1) are connected. Similarly, the positions of the ends of each pipe are aligned so that one of the second refrigerant pipes (F2) and the second metal pipe (M2) are connected. The positions of the ends of each pipe are aligned so that the other second refrigerant pipe (F2) and the third metal pipe (M3) are connected. Note that the alignment of the second refrigerant pipe (F2) may be performed prior to the alignment of the first refrigerant pipe (F1).

[0070] In the second step, one end of the connecting pipe (C) and one end of the first refrigerant pipe (F1) are brazed, and then the other end of the connecting pipe (C) and one end of the second refrigerant pipe (F2) are brazed. In this embodiment, the right end of the first metal pipe (M1) and the left end of the first refrigerant pipe (F1) are brazed. Then, the left end of the second metal pipe (M2) and the right end of one of the second refrigerant pipes (F2) are brazed. And the left end of the third metal pipe (M3) and the right end of the other second refrigerant pipe (F2) are brazed. Note that the brazing order may be any of the first metal pipe (M1), the second metal pipe (M2), and the third metal pipe (M3) first.

[0071] (4) Features (4-1) In this embodiment, the shortest distance L1 between the first coated end (R1) and the first pipe end (15) is greater than the shortest distance L2 between the first coated end (R1) and the second coated end (R2). Therefore, the first pipe end (15) is sufficiently separated from the coating member (R). Thus, melting of the coating member (R) during brazing the first pipe portion (11) and the first fluid member (F1) can be suppressed.

[0072] (4-2) In this embodiment, the shortest distance L3 between the second covering end portion (R2) and the second pipe end portion (16) is greater than the shortest distance L2. Therefore, the second pipe end portion (16) is sufficiently separated from the covering member (R). Thus, melting of the covering member (R) during brazing the second pipe portion (12) and the second fluid member (F2) can be suppressed.

[0073] (4-3) In this embodiment, the thin-walled portion (31) is covered with the covering member (R). Therefore, the thin-walled portion (31) with low pressure resistance can be reinforced.

[0074] (4-4) In this embodiment, the brazed portion (33) is covered with the covering member (R). Therefore, the portion whose pressure resistance has been reduced by brazing can be reinforced.

[0075] (4-5) In this embodiment, the brazed portion (33) is formed between the second connection portion (22) and the third connection portion (23). The brazed portion (33) is likely to have its pressure resistance reduced by heat treatment. Therefore, by covering the brazed portion (33) with the covering member (R), the portion with low pressure resistance can be reinforced.

[0076] (4-6) In this embodiment, the covering member (R) is made of resin. Therefore, the shape and thickness of the covering member (R) can be freely set.

[0077] (4-7) In this embodiment, the small-diameter portion (42) of the first metal pipe (M1) is disposed inside the opening on one end side of the branch pipe (10). Thereby, a step is less likely to occur at the connection portion between the first metal pipe (M1) and the branch pipe (10). Therefore, when the connecting pipe (C) thermally expands, breakage of the covering member (R) due to the step can be suppressed.

[0078] (4-8) In this embodiment, the refrigeration device (1) includes the first refrigerant pipe (F1), the second refrigerant pipe (F2), and the connecting pipe (C). Therefore, a refrigeration device (1) that suppresses melting of the covering member of the connecting pipe (C) can be provided.

[0079] (4-9) In the connection method of the connecting pipe of the present embodiment, an arrangement step of arranging a connecting pipe (C) between a first refrigerant pipe (F1) and a second refrigerant pipe (F2), and brazing one end of the connecting pipe (C) and one end of the first refrigerant pipe (F1), and brazing the other end of the connecting pipe (C) and one end of the second refrigerant pipe (F2) are included. In the connecting pipe (C) of the present embodiment, since the shortest distance L1 between the first coated end (R1) and the first pipe end (15) is larger than the shortest distance L2 between the first coated end (R1) and the second coated end (R2), the first pipe end (15) is sufficiently separated from the coating member (R). Therefore, melting of the coating member (R) can be suppressed in the brazing process.

[0080] (4-10) In the present embodiment, the connecting pipe (C) has a coating member (R). Here, when using a high-pressure refrigerant such as a CO2 refrigerant as the refrigerant filled in the refrigerant circuit (2), compared with the case of using a conventional fluorocarbon refrigerant (for example, R32 refrigerant), it is necessary to improve the pressure resistance of the connecting pipe (C). In order to improve the pressure resistance of the connecting pipe (C), it is conceivable to increase the thickness of the pipe, but the material cost increases and the workability deteriorates.

[0081] In the present embodiment, since the connecting pipe (C) has a coating member (R), the pressure resistance can be improved. Thereby, even when using a new refrigerant, by using the connecting pipe (C) provided with the coating member (R) on the same metal pipe as the metal pipe used when using the conventional refrigerant, an increase in material cost can be suppressed to a low level and deterioration of workability can also be reduced.

[0082] (5) Modification The above embodiment may be modified as follows. In the following description, differences from the above embodiment will be described in principle.

[0083] (5-1) Modification 1 As shown in FIG. 3, in the connection pipe (C) of the present embodiment, the covering member (R) may be provided in the connection pipe (C) so as to mainly cover a portion where the wall thickness of the pipe is thin. FIG. 3(a) shows a longitudinal sectional view of the connection portions (22, 23) of the branch pipe (10), and FIG. 3(b) shows a longitudinal sectional view of the connection pipe (C).

[0084] Specifically, the covering member (R) of this modification covers the thin-walled portion (31) of the branch pipe (10). In the covering member (R) of this modification, a part of the outer peripheral surface of the first connection portion (21) of the branch pipe (10) is not covered as compared with the covering member (R) of the above embodiment, and the portion covering the second metal pipe (M2) and the third metal pipe (M3) is also shortened.

[0085] The covering member (R) of this modification covers the thin-walled portion (31) where the pressure resistance is likely to be low, so that the amount of the covering member (R) can be minimized while improving the pressure resistance of the connection pipe (C).

[0086] (5-2) Modification 2 As shown in FIG. 4, in the connection pipe (C) of the present embodiment, the covering member (R) may be provided in the connection pipe (C) so that the thickness becomes thicker at a position corresponding to a portion where the wall thickness of the pipe is thin. FIG. 4(a) shows a longitudinal sectional view of the connection portions (22, 23) of the branch pipe (10), and FIG. 4(b) shows a longitudinal sectional view of the connection pipe (C).

[0087] The covering member (R) of this modification has a main covering portion (51) and a reinforcing portion (52). The thickness of the reinforcing portion (52) is thicker than the thickness of the main covering portion (51). The main covering portion (51) is disposed at a position on the outer peripheral surface of the connection pipe (C) that mainly overlaps with the thick-walled portion (32) of the branch pipe (10). The reinforcing portion (52) of this modification is disposed at a position on the outer peripheral surface of the connection pipe (C) that mainly overlaps with the thin-walled portion (31) of the branch pipe (10).

[0088] Specifically, as shown in FIG. 4(b), the reinforcing portion (52) provided around the thin-walled portion (31) has a thickness approximately three times that of the main covering portion (51) provided around the thick-walled portion (32). Note that the ratio of the reinforcing portion (52) to the main covering portion (51) is merely an example.

[0089] In this way, by arranging the thick reinforcing portion (52) of the covering member (R) at a position overlapping with the thin-walled portion (31) of the branch pipe (10) that is likely to have low pressure resistance, the pressure resistance of the thin-walled portion (31) can be further improved.

[0090] (5-3) Modification Example 3 As shown in FIG. 5, in the connection pipe (C) of the present embodiment, the covering member (R) may be provided such that the thickness at a position corresponding to the brazing portion (33) becomes thick. FIG. 5(a) shows a longitudinal sectional view of the connection portions (22, 23) of the branch pipe (10), and FIG. 5(b) shows a longitudinal sectional view of the connection pipe (C).

[0091] The covering member (R) of this modification example has a main covering portion (51) and a reinforcing portion (52). The thickness of the reinforcing portion (52) is thicker than the thickness of the main covering portion (51). The main covering portion (51) is disposed at a position on the outer peripheral surface of the connection pipe (C) that mainly overlaps with the thick-walled portion (32) of the branch pipe (10). The reinforcing portion (52) of this modification example is disposed at a position on the outer peripheral surface of the connection pipe (C) that mainly overlaps with the brazing portion (33) of the branch pipe (10).

[0092] Specifically, as shown in FIG. 5(a), the reinforcing portion (52) provided around the brazing portion (33) has a thickness approximately four times that of the main covering portion (51) provided around the thick-walled portion (32). Note that the ratio of the reinforcing portion (52) to the main covering portion (51) is merely an example.

[0093] In this way, by arranging the thick reinforcing portion (52) of the covering member (R) at a position overlapping with the brazing portion (33) of the branch pipe (10) that is likely to have low pressure resistance, the pressure resistance of the brazing portion (33) can be further improved.

[0094] (5-4) Modification Example 4 As shown in FIG. 6, in the connection pipe (C) of the present embodiment, a sealing member (E) for suppressing the inflow of fluid may be disposed between the connection pipe (C) and the covering member (R). FIG. 6(a) shows a longitudinal sectional view of the connection portions (22, 23) of the branch pipe (10), and FIG. 6(b) shows a longitudinal sectional view of the connection pipe (C). The sealing member (E) is disposed on the outer peripheral surface of the covering member (R). In this modification, as shown in FIG. 6, the sealing member (E) is disposed at the first covering end (R1) and the second covering end (R2) of the covering member (R). The sealing member (E) of this modification is a heat-shrinkable tube.

[0095] Here, when the difference between the temperature of the refrigerant flowing through the connection pipe (C) and the temperature of the air around the connection pipe (C) is large, if a gap allowing free entry and exit of air is formed between the connection pipe (C) and the covering member (R), the dew condensation water generated in this gap increases. Further, if a gap allowing free entry and exit as described above is formed, for example, the dew condensation water generated in the first refrigerant pipe (F1) or the second refrigerant pipe (F2) travels along the connection pipe (C) and enters the above gap, thereby increasing the dew condensation water in this gap. Thus, in some cases, the increased dew condensation water freezes in the above gap, damaging the covering member (R).

[0096] In this modification, by sealing the first covering end (R1) and the second covering end (R2) of the covering member (R) with a heat-shrinkable tube, the inflow of fluid is suppressed between the connection pipe (C) and the covering member (R). Thereby, it is possible to prevent the covering member (R) from being damaged by the dew condensation water generated or flowing in between the connection pipe (C) and the covering member (R).

[0097] The sealing member (E) may be a binding band or a hose band that tightens the covering member (R) with respect to the connection pipe (C). In this case, the sealing member (E) does not necessarily have to be disposed at the end of the covering member (R).

[0098] (5-5) Modification 5 In the connection pipe (C) of the present embodiment, a through hole for draining water may be formed in the covering member (R). The through hole for draining water is a small hole that penetrates in the thickness direction of the covering member (R). A large number of through holes are formed in the covering member (R) over the entire covering member (R). Thereby, the condensed water generated in the gap between the connection pipe (C) and the covering member (R) or the condensed water that has flowed in is discharged from the through holes, so that damage to the covering member (R) can be suppressed.

[0099] (5-6) Modification 6 The covering member (R) of the connection pipe (C) of the present embodiment may be configured by combining the covering members (R) of the above Modifications 1 to 5.

[0100] 《Embodiment 2》 Embodiment 2 will be described. The refrigeration device (1) of the present embodiment is a modification of the refrigeration device (1) of Embodiment 1 in which the configuration of the connection pipe (C) is changed. Here, the differences between the connection pipe (C) of the present embodiment and the connection pipe (C) of Embodiment 1 will be described.

[0101] (1) Connection pipe The connection pipe (C) of the present embodiment is used, for example, for the fourth connection pipe (9) in FIG. 1. As shown in FIG. 7, the connection pipe (C) is disposed between the first refrigerant pipe (F1) and the second refrigerant pipe (F2). The connection pipe (C) of the present embodiment connects the first refrigerant pipe (F1) and two second refrigerant pipes (F2). The connection pipe (C) of the present embodiment includes a first metal pipe (M1), a second metal pipe (M2), and a covering member (R). The first metal pipe (M1) and the second metal pipe (M2) are made of copper or a copper alloy, aluminum or an aluminum alloy (metal).

[0102] One end (the right end in FIG. 7) of the first metal pipe (M1) is connected to the first refrigerant pipe (F1), and the other end (the left end in FIG. 7) is connected to one end (the right end in FIG. 7) of the second metal pipe (M2). The structure of the first metal pipe (M1) is the same as that of Embodiment 1.

[0103] The second metal tube (M2) is a copper tube having a substantially circular cross-section. The outer diameter and the inner diameter of the second metal tube (M2) are substantially constant over the entire length. The second metal tube (M2) has a curved portion (60), a first straight portion (61), a second straight portion (62), and a third straight portion (63). The curved portion (60), the first straight portion (61), the second straight portion (62), and the third straight portion (63) are integrally formed.

[0104] The curved portion (60) is a portion formed in an arcuate shape convex toward the first metal tube (M1). The first straight portion (61) is a portion extending straight from the top of the curved portion (60). The first straight portion (61) extends in the axial direction of the first metal tube (M1). The right end of the first straight portion (61) is the right end of the second metal tube (M2).

[0105] The second straight portion (62) extends straight from the upper end of the curved portion (60). The third straight portion (63) extends straight from the lower end of the curved portion (60). The second straight portion (62) and the third metal tube (M3) extend in the axial direction of the first metal tube (M1). The second straight portion (62) and the third straight portion (63) may extend in a direction having a predetermined angle with respect to the axial direction of the first metal tube (M1). For example, the second straight portion (62) and the third straight portion (63) may extend away from each other as they go toward the second refrigerant pipe (F2). The left ends of the second straight portion (62) and the third straight portion (63) are the left end of the second metal tube (M2).

[0106] The left end of the second straight portion (62) is connected to the right end of the upper second refrigerant pipe (F2). The left end of the third straight portion (63) is connected to the right end of the lower second refrigerant pipe (F2). The right end of the first straight portion (61) is connected to the left end of the first metal pipe (M1). Here, the small-diameter portion (42) formed at the left end of the first metal pipe (M1) is disposed inside the first straight portion (61) of the second metal pipe (M2). In other words, the small-diameter portion (42) of the first metal pipe (M1) is disposed inside the opening at one end side of the second metal pipe (M2). Therefore, the outer peripheral surface of the large-diameter portion (41) of the first metal pipe (M1) and the outer peripheral surface of the first straight portion (61) of the second metal pipe (M2) are flush with each other, and no step is formed between the two outer peripheral surfaces.

[0107] The second metal pipe (M2) includes a thin-wall portion (31) and a thick-wall portion (32). The thin-wall portion (31) of the present embodiment is formed at the outer portion of the curved portion (60) and the first straight portion (61). The thick-wall portion (32) of the present embodiment is formed at the second straight portion (62) and the third straight portion (63). The pipe thickness of the outer portion of the curved portion (60) and the first straight portion (61) is thinner than the pipe thickness of the second straight portion (62) and the third straight portion (63). The second metal pipe (M2) of the present embodiment is manufactured by a bulging process. The thin-wall portion (31) is formed in the process of performing the bulging process.

[0108] The connecting pipe (C) has a first pipe portion (11) and a second pipe portion (12). In the present embodiment, the first metal pipe (M1) corresponds to the first pipe portion (11), and the second metal pipe (M2) corresponds to the second pipe portion (12). The right end of the first metal pipe (M1) corresponds to the first pipe end portion (15) of the present disclosure. The left ends of the second straight portion (62) and the third straight portion (63) of the second metal pipe (M2) correspond to the second pipe end portion (16) of the present disclosure.

[0109] The covering member (R) of this embodiment covers the outer peripheral surfaces of a part of the first metal pipe (M1) and a part of the second metal pipe (M2). Specifically, the covering member (R) covers the curved portion (60) of the second metal pipe (M2) and the vicinity of the curved portion (60). The first covering end (R1) of the covering member (R) of this embodiment is the end on the side of the first straight portion (61) in the axial direction of the first metal pipe (M1). The second covering end (R2) is the end on the sides of the second straight portion (62) and the third straight portion (63) in the axial direction of the first metal pipe (M1).

[0110] In this embodiment, the thin-walled portion (31) of the second metal pipe (M2) is covered with the covering member (R). Due to its structure, the thin-walled portion (31) is likely to have low pressure resistance. Therefore, by covering the thin-walled portion (31) with the covering member (R), the portion with low pressure resistance can be reinforced, and the pressure resistance of the connecting pipe (C) can be improved.

[0111] Also, in this embodiment, there is no step at the connection portion between the first metal pipe (M1) and the second metal pipe (M2). Therefore, when the connecting pipe (C) thermally expands, even if the connecting pipe (C) expands in the direction in which the first straight portion (61) extends, there is no step at the connection portion, so the covering member (R) is less likely to be damaged.

[0112] Also in this embodiment, as shown in FIG. 7, the shortest distance L1 between the first covering end (R1) and the first pipe end (15) is greater than the shortest distance L2 between the first covering end (R1) and the second covering end (R2) (L2 < L1). Therefore, the first pipe end (15) is sufficiently separated from the covering member (R). Thus, when brazing the first metal pipe (M1) and the first refrigerant pipe (F1), it is possible to suppress the covering member (R) from melting due to the heat of brazing.

[0113] Also, the shortest distance L3 between the second covering end (R2) and the second pipe end (16) is greater than the shortest distance L2 (L2 < L3). Therefore, the second pipe end (16) is sufficiently separated from the covering member (R). Thus, when brazing the second metal pipe (M2) and the second refrigerant pipe (F2), it is possible to suppress the covering member (R) from melting due to the heat of brazing.

[0114] In addition, when the axial lengths of the second straight portion (62) and the third straight portion (63) of the second metal tube (M2) are different, the shortest distance L3 is the distance between the second tube end portion (16) closer to the second covering end portion (R2) and the second covering end portion (R2).

[0115] (2) Modified Example As the covering member (R) of the connection pipe (C) of the present embodiment, the covering members (R) of Modified Examples 1, 2, 4 to 6 of the above-described Embodiment 1 may be applied.

[0116] 《Embodiment 3》 Embodiment 3 will be described. The refrigeration device (1) of the present embodiment is obtained by changing the configuration of the connection pipe (C) in the refrigeration device (1) of Embodiment 1. Here, the differences between the connection pipe (C) of the present embodiment and the connection pipe (C) of Embodiment 1 will be described.

[0117] (1) Connection Pipe The connection pipe (C) of the present embodiment is used, for example, as the third connection pipe (8) in FIG. 1. As shown in FIG. 8, the connection pipe (C) is disposed between the first refrigerant pipe (F1) and the second refrigerant pipe (F2). The connection pipe (C) of the present embodiment connects three first refrigerant pipes (F1) and two second refrigerant pipes (F2). The connection pipe (C) of the present embodiment includes a first metal pipe (M1), a second metal pipe (M2), and a covering member (R). The first metal pipe (M1) and the second metal pipe (M2) are made of copper or a copper alloy, or aluminum or an aluminum alloy (metal).

[0118] One end (the lower end in FIG. 8) of each first metal pipe (M1) is connected to the first refrigerant pipe (F1), and the other end (the upper end in FIG. 8) is connected to one end (the lower end in FIG. 8) of the second metal pipe (M2). The structure of the first metal pipe (M1) is the same as that in Embodiment 1.

[0119] The second metal pipe (M2) has a plurality (three in the present embodiment) of short pipe portions (71) and one long pipe portion (72).

[0120] The short tube portion (71) and the long tube portion (72) are integrally formed. The short tube portion (71) is the portion of the second metal tube (M2) with a short length. The first metal tube (M1) is connected to the lower end of each short tube portion (71). Each short tube portion (71) extends straight in the axial direction of the first metal tube (M1). Each short tube portion (71) has a substantially circular longitudinal cross-section. Each short tube portion (71) is connected to an intermediate portion of the long tube portion (72). The short tube portions (71) are arranged side by side at a predetermined interval in the direction in which the long tube portion (72) extends.

[0121] The long tube portion (72) is the portion of the second metal tube (M2) with a long length. The long tube portion (72) extends straight in a direction intersecting the direction in which the short tube portion (71) extends. The long tube portion (72) has a substantially circular cross-section. The long tube portion (72) is formed continuously with the short tube portion (71).

[0122] The second refrigerant pipes (F2) are connected to the left and right ends of the long tube portion (72) respectively. The upper end of the first metal tube (M1) is connected to the lower end of each short tube portion (71). Here, the small-diameter portion (42) formed at the upper end of the first metal tube (M1) is disposed inside the lower end of the short tube portion (71) of the second metal tube (M2). In other words, the small-diameter portion (42) of the first metal tube (M1) is disposed inside the opening on one end side of the second metal tube (M2). Therefore, the outer peripheral surface of the large-diameter portion (41) of the first metal tube (M1) and the outer peripheral surface of the short tube portion (71) of the second metal tube (M2) are flush, and no step is formed between the two outer peripheral surfaces.

[0123] The second metal tube (M2) includes a thin-wall portion (31) and a thick-wall portion (32). The thin-wall portion (31) of the present embodiment is formed on the short tube portion (71). The thin-wall portion (31) is formed at least at the base end portion (the portion connected to the long tube portion) of the short tube portion (71). The thick-wall portion (32) of the present embodiment is formed on the long tube portion (72). The wall thickness of the short tube portion (71) is thinner than the wall thickness of the long tube portion (72). The second metal tube (M2) of the present embodiment is manufactured by bulge processing. The thin-wall portion (31) is formed in the process of performing bulge processing.

[0124] The connecting pipe (C) has a first pipe portion (11) and a second pipe portion (12). In the present embodiment, the first metal pipe (M1) corresponds to the first pipe portion (11), and the second metal pipe (M2) corresponds to the second pipe portion (12). The lower end portion of the first metal pipe (M1) corresponds to the first pipe end portion (15) of the present disclosure.

[0125] The covering member (R) of the present embodiment covers the outer peripheral surfaces of a part of the first metal pipe (M1) and a part of the second metal pipe (M2). The covering member (R) covers at least the short pipe portion (71) of the second metal pipe (M2). The first covering end portion (R1) of the covering member (R) of the present embodiment is the end portion on the short pipe portion (71) side in the axial direction of the first metal pipe (M1). The second covering end portion (R2) is the end portion on the long pipe portion (72) side in the axial direction of the first metal pipe (M1).

[0126] In the present embodiment, the thin-walled portion (31) of the second metal pipe (M2) is covered with the covering member (R). Due to its structure, the thin-walled portion (31) is likely to have low pressure resistance. Therefore, by covering the thin-walled portion (31) with the covering member (R), the portion with low pressure resistance can be reinforced, and thus the pressure resistance of the connecting pipe (C) can be improved.

[0127] Also, in the present embodiment, there is no step at the connection portion between the first metal pipe (M1) and the second metal pipe (M2). Therefore, when the connecting pipe (C) thermally expands, even if the connecting pipe (C) expands in the extending direction of the first metal pipe (M1), since there is no step at the connection portion, the covering member (R) is less likely to be damaged.

[0128] Also in the present embodiment, as shown in FIG. 8, the shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is greater than the shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2) (L2 < L1). Therefore, the first pipe end portion (15) is sufficiently separated from the covering member (R). Thus, when brazing the first metal pipe (M1) and the first refrigerant pipe (F1), it is possible to suppress the melting of the covering member (R) due to the heat of brazing.

[0129] (2) Modified Example The covering member (R) of the connecting pipe (C) of the present embodiment may be the covering member (R) of Modifications 1, 2, 4 to 6 of the above-described Embodiment 1.

[0130] <<Embodiment 4>> Embodiment 4 will be described. The refrigeration apparatus (1) of the present embodiment is obtained by changing the configuration of the connecting pipe (C) in the refrigeration apparatus (1) of Embodiment 1. Here, the differences between the connecting pipe (C) of the present embodiment and the connecting pipe (C) of Embodiment 1 will be described.

[0131] (1) Connecting pipe As shown in FIG. 9, the connecting pipe (C) of the present embodiment connects one first refrigerant pipe (F1) and one second refrigerant pipe (F2). The connecting pipe (C) of the present embodiment is used as a filter, a muffler, and a check valve by housing functional components therein.

[0132] The connecting pipe (C) of the present embodiment includes an enlarged pipe (80), a first metal pipe (M1), a second metal pipe (M2), and a covering member (R). The enlarged pipe (80), the first metal pipe (M1), and the second metal pipe (M2) are made of copper or a copper alloy, or aluminum or an aluminum alloy (metal).

[0133] One end (the right end in FIG. 9) of the first metal pipe (M1) is connected to the first refrigerant pipe (F1), and the other end (the left end in FIG. 9) is connected to the enlarged pipe (80). One end (the right end in FIG. 9) of the second metal pipe (M2) is connected to the enlarged pipe (80), and the other end (the left end in FIG. 9) is connected to the second refrigerant pipe (F2).

[0134] Unlike the first metal pipe (M1) of Embodiment 1, the first metal pipe (M1) of the present embodiment does not have a large-diameter portion (41) and a small-diameter portion (42). In other words, the outer diameter and the inner diameter of the first metal pipe (M1) of the present embodiment are substantially constant over the entire length. Similar to the first metal pipe (M1) of Embodiment 1, the first metal pipe (M1) of the present embodiment may have a small-diameter portion (42) at one end portion thereof. The second metal pipe (M2) of the present embodiment has the same configuration as the first metal pipe (M1).

[0135] The enlarged pipe (80) has an outer diameter larger than those of the first metal pipe (M1) and the second metal pipe (M2). The enlarged pipe (80) is a horizontally long pipe. The enlarged pipe (80) extends in the axial direction of the first metal pipe (M1) and the second metal pipe (M2). One end portion (the right end portion in FIG. 9) of the enlarged pipe (80) is connected to the left end portion of the first metal pipe (M1), and the other end portion (the left end portion in FIG. 9) thereof is connected to the right end portion of the second metal pipe (M2). Specifically, the left end portion of the first metal pipe (M1) is disposed inside the opening on one end side of the enlarged pipe (80). The right end portion of the second metal pipe (M2) is disposed inside the opening on the other end side of the enlarged pipe (80).

[0136] The enlarged pipe (80) includes a thin-walled portion (31) and a thick-walled portion (32). The thin-walled portion (31) of the present embodiment is formed at the central portion of the enlarged pipe (80). The thick-walled portion (32) of the present embodiment is formed at both the left and right end portions of the enlarged pipe (80). The wall thickness of the pipe at the central portion of the enlarged pipe (80) is thinner than the wall thicknesses of the pipes at both the left and right end portions of the enlarged pipe (80). The enlarged pipe (80) of the present embodiment is manufactured by a bulging process. The thin-walled portion (31) is formed during the bulging process.

[0137] The connecting pipe (C) has a first pipe portion (11) and a second pipe portion (12). In the present embodiment, the first metal pipe (M1) corresponds to the first pipe portion (11), and the enlarged pipe (80) and the second metal pipe (M2) correspond to the second pipe portion (12). In other words, the second pipe portion (12) is the portion of the connecting pipe (C) other than the first pipe portion (11). The right end portion of the first metal pipe (M1) corresponds to the first pipe end portion (15) of the present disclosure. The left end portion of the second metal pipe (M2) corresponds to the second pipe end portion (16) of the present disclosure.

[0138] The covering member (R) of the present embodiment covers the entire outer peripheral surface of the enlarged pipe (80), a part of the first metal pipe (M1), and a part of the second metal pipe (M2). Specifically, the covering member (R) covers the enlarged pipe (80) and the vicinity of the enlarged pipe (80). The first covering end (R1) of the covering member (R) of the present embodiment is the end on the first metal pipe (M1) side in the axial direction of the first metal pipe (M1). The second covering end (R2) is the end on the second metal pipe (M2) side in the axial direction of the first metal pipe (M1).

[0139] In the present embodiment, the thin-walled portion (31) of the enlarged pipe (80) is covered with the covering member (R). Due to its structure, the thin-walled portion (31) is likely to have low pressure resistance. Therefore, by covering the thin-walled portion (31) with the covering member (R), the portion with low pressure resistance can be reinforced, and thus the pressure resistance of the connecting pipe (C) can be improved.

[0140] Also in the present embodiment, as shown in FIG. 9, the shortest distance L1 between the first covering end (R1) and the first pipe end (15) is greater than the shortest distance L2 between the first covering end (R1) and the second covering end (R2) (L2 < L1). Therefore, the first pipe end (15) is sufficiently separated from the covering member (R). Thus, when brazing the first metal pipe (M1) and the first refrigerant pipe (F1), it is possible to suppress the melting of the covering member (R) due to the heat of brazing.

[0141] Further, the shortest distance L3 between the second covering end (R2) and the second pipe end (16) is greater than the shortest distance L2 (L2 < L3). Therefore, the second pipe end (16) is sufficiently separated from the covering member (R). Thus, when brazing the second metal pipe (M2) and the second refrigerant pipe (F2), it is possible to suppress the melting of the covering member (R) due to the heat of brazing.

[0142] (2) Modification The above embodiment may be modified as follows. In the following description, differences from the above embodiment will be described in principle.

[0143] (2-1) Modification 1 As shown in Fig. 10, in the connecting pipe (C) of the present embodiment, the covering member (R) may be provided so as to cover only the portion where the pipe thickness is thin in the connecting pipe (C).

[0144] Specifically, the covering member (R) of this modification covers only the thin-walled portion (31) of the enlarged pipe (80). By covering only the thin-walled portion (31) that is likely to have low pressure resistance, the amount of the covering member (R) can be minimized while improving the pressure resistance of the connecting pipe (C).

[0145] (2-2) Modification 2 As shown in Fig. 11, in the connecting pipe (C) of the present embodiment, the covering member (R) may be provided such that the thickness at the position corresponding to the portion where the pipe thickness is thin in the connecting pipe (C) becomes thicker.

[0146] The covering member (R) of this modification has a main covering portion (51) and a reinforcing portion (52). The thickness of the reinforcing portion (52) is thicker than the thickness of the main covering portion (51). The main covering portion (51) is disposed at a position overlapping the thin-walled portion (31) on the outer peripheral surface of the enlarged pipe (80). The reinforcing portion (52) is disposed at a position overlapping the central portion where the wall thickness is thinnest among the thin-walled portions (31) on the outer peripheral surface of the enlarged pipe (80).

[0147] In this way, by disposing the thick reinforcing portion (52) of the covering member (R) at a position overlapping the thinnest portion where the pressure resistance is most likely to be the lowest in the enlarged pipe (80), the pressure resistance of the thin-walled portion (31) can be further improved.

[0148] (2-3) Modification 3 As shown in Fig. 12, in the connecting pipe (C) of the present embodiment, a sealing member (E) for suppressing the inflow of fluid may be disposed between the connecting pipe (C) and the covering member (R).

[0149] The sealing member (E) is disposed on the outer peripheral surface of the covering member (R). In this modified example, as shown in FIG. 12, the sealing member (E) is disposed on the first covering end portion (R1) and the second covering end portion (R2) of the covering member (R). The sealing member (E) of this modified example is a heat-shrinkable tube.

[0150] Similar to the connection pipe (C) of the first embodiment, in the connection pipe (C) of the present embodiment, if a gap allowing free entry and exit of air is formed between the connection pipe (C) and the covering member (R), the dew condensation water generated in this gap may increase, or the dew condensation water generated outside the connection pipe (C) may enter the above gap.

[0151] In this modified example, by sealing the first covering end portion (R1) and the second covering end portion (R2) of the covering member (R) with a heat-shrinkable tube, the inflow of fluid is suppressed between the connection pipe (C) and the covering member (R). Thereby, it is possible to prevent the covering member (R) from being damaged by the dew condensation water generated or flowing in between the connection pipe (C) and the covering member (R).

[0152] The sealing member (E) may be a binding band or a hose band that tightens the covering member (R) with respect to the connection pipe (C). In this case, the sealing member (E) does not have to be disposed at the end portion of the covering member (R).

[0153] (2-4) Modified Example 4 As shown in FIG. 13, in the connection pipe (C) of the present embodiment, a through hole (54) for draining water may be formed in the covering member (R).

[0154] The through hole (54) penetrates in the thickness direction of the covering member (R). A large number of through holes (54) are formed over the entire covering member (R). Thereby, the dew condensation water generated or flowing in the gap between the connection pipe (C) and the covering member (R) is discharged from the through hole (54), so that damage to the covering member (R) can be suppressed.

[0155] (2-5) Modified Example 5 As shown in FIG. 14, the covering member (R) of the present embodiment may be vertically divided into two parts. Specifically, the covering member (R) of this modification is composed of a first covering member (57) disposed above the connecting pipe (C) and a second covering member (58) disposed below the connecting pipe (C). The first covering member (57) and the second covering member (58) are formed in an arc shape with a certain thickness. The first covering member (57) and the second covering member (58) are tightened by a hose band (59) provided on their outer sides and fixed to the connecting pipe (C).

[0156] (2-6) Modification 6 The covering member (R) of the connecting pipe (C) of the present embodiment may be configured by combining the covering members (R) of the above Modifications 1 to 5.

[0157] 《Other Embodiments》 Regarding the above embodiment, it may have the following configuration.

[0158] In the connecting pipe (C) of each of the above embodiments, the first fluid member and the second fluid member may not be pipes. For example, the first fluid member and the second fluid member may be headers of a heat exchanger or the like.

[0159] Also, in the connecting pipe (C) of each of the above embodiments, the covering member (R) may be made of a material other than resin. For example, the covering member (R) may be ceramic.

[0160] Although the embodiments and modifications have been described above, it will be understood that various changes in form and details are possible without departing from the spirit and scope of the claims. Also, the elements according to the above embodiments, modifications, and other embodiments may be combined or replaced as appropriate.

[0161] The descriptions such as "first", "second", "third",... described above are used to distinguish the phrases to which these descriptions are given, and do not limit the number or order of those phrases either.

Industrial Applicability

[0162] As described above, the present disclosure is useful for connecting pipes, refrigeration devices, and connection methods of connecting pipes.

Description of Reference Numerals

[0163] 1 Refrigeration device 10 Branch pipe 11 First pipe portion 12 Second pipe portion 15 First pipe end 16 Second pipe end 22, 23 Connection portion 31 Thin-walled portion 33 Brazed portion 41 Large-diameter portion 42 Small-diameter portion 51 Main covering portion 52 Reinforcing portion 60 Bending portion 61 First straight portion 62 Second straight portion 63 Third straight portion 71 Short pipe portion 72 Long pipe portion 80 Enlarged pipe C Connection pipe E Sealing member F1 First refrigerant pipe (first fluid member) F2 Second refrigerant pipe (second fluid member) M1 First metal pipe M2 Second metal pipe M3 Third metal pipe R Coating member R1 First coating end R2 Second coating end

Claims

1. A metal connecting pipe disposed between a first fluid member (F1) and a second fluid member (F2) through which a fluid flows and connecting the two, comprising: a first pipe portion (11) having a first pipe end portion (15) to which the first fluid member (F1) is connected; a second pipe portion (12) having the first pipe portion (11) connected to one end and the second fluid member (F2) connected to the other end; a covering member (R) covering at least a part of the second pipe portion (12); the covering member (R) having a first covering end portion (R1) which is an end portion on the first pipe portion (11) side in the axial direction of the first pipe portion (11), and a second covering end portion (R2) which is an end portion on the side opposite to the first covering end portion (R1) in the axial direction; wherein a shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is greater than a shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2). Connecting pipe.

2. The covering member (R) covers a part of the second pipe portion (12), the second pipe portion (12) has a second pipe end portion (16) to which the second fluid member (F2) is connected, and a shortest distance L3 between the second covering end portion (R2) and the second pipe end portion (16) is greater than the shortest distance L2. The connecting pipe according to Claim 1.

3. The second pipe portion (12) has a thick wall portion (32) and a thin wall portion (31) having a thickness thinner than that of the thick wall portion (32), and the thin wall portion (31) is covered with the covering member (R). The connecting pipe according to Claim 1 or 2.

4. The first pipe portion (11) is a first metal pipe (M1) made of metal, the second pipe portion (12) is a second metal pipe (M2) made of metal, the second metal pipe (M2) has a curved portion (60) formed in an arc shape, a first straight portion (61) extending in the axial direction from the top of the curved portion (60) and connecting to the first metal pipe (M1), and second straight portions (62) and third straight portions (63) extending from each end of the curved portion (60), and the thin wall portion (31) is formed in the curved portion (60) of the second metal pipe (M2). The connecting pipe according to Claim 3.

5. The first pipe portion (11) is a first metal pipe (M1) made of metal, the second pipe portion (12) includes an enlarged pipe (80) made of metal and a second metal pipe (M2), the enlarged pipe (80) has the first metal pipe (M1) connected to one end and the second metal pipe (M2) connected to the other end, having an outer diameter larger than that of the first metal tube (M1) and the second metal tube (M2), the thin-walled portion (31) is formed in the enlarged tube (80) The connecting pipe according to claim 3.

6. The first pipe portion (11) is a first metal pipe (M1) made of metal, The second pipe portion (12) is a second metal pipe (M2) made of metal, The second metal pipe (M2) has a plurality of short pipe portions (71) to which each of the plurality of first metal pipes (M1) is connected, and one long pipe portion (72) extending in a direction intersecting the direction in which the short pipe portions (71) extend and formed continuously with the short pipe portions (71), the thin-walled portion (31) is formed at the base end portion of the short pipe portion (71) The connecting pipe according to claim 3.

7. The second pipe portion (12) has a brazed portion (33) brazed thereto, the brazed portion (33) is covered with the covering member (R) The connecting pipe according to claim 1 or 2.

8. The first pipe portion (11) is a first metal pipe (M1) made of metal, The second pipe portion (12) includes a second metal pipe (M2), a third metal pipe (M3), and a branch pipe (10) made of metal, the branch pipe (10) branches the fluid flowing through the first metal pipe (M1) into the second metal pipe (M2) and the third metal pipe (M3), two connection portions (22, 23) to which the second metal pipe (M2) and the third metal pipe (M3) are respectively connected and provided adjacent to each other are formed in the branch pipe (10), the brazed portion (33) is formed between the connection portion (22) on the second metal pipe (M2) side and the connection portion (23) on the third metal pipe (M3) side The connecting pipe according to claim 7.

9. The covering member (R) has a main covering portion (51) and a reinforcing portion (52) thicker than the main covering portion (51), the reinforcing portion (52) is disposed at a position overlapping the thin-walled portion (31) The connecting pipe according to claim 3.

10. The covering member (R) has a main covering portion (51) and a reinforcing portion (52) thicker than the main covering portion (51), the reinforcing portion (52) is disposed at a position overlapping the brazed portion (33) The connecting pipe according to claim 7.

11. The covering member (R) is made of resin The connecting pipe according to claim 1 or 2.

12. Further provided is a sealing member (E) which is disposed on the outer peripheral surface of the covering member (R) and suppresses the inflow of fluid between the connection pipe (C) and the covering member (R). The connection pipe according to claim 1 or 2.

13. The covering member (R) covers the first pipe portion (11) and the second pipe portion (12). The first pipe portion (11) includes a large-diameter portion (41) formed in a middle portion of the first pipe portion (11), and a small-diameter portion (42) formed at an end connected to one end of the second pipe portion (12) and having an outer diameter smaller than that of the large-diameter portion (41). The small-diameter portion (42) is disposed inside the opening on one end side of the second pipe portion (12). The connection pipe according to claim 1 or 2.

14. A refrigeration device including the first fluid member (F1), the second fluid member (F2), and the connection pipe (C) according to claim 1 or 2. Refrigeration device.

15. A connection method of a metal connection pipe (C) disposed between a first fluid member (F1) and a second fluid member (F2) made of metal through which fluid flows and connecting the two, wherein the connection pipe (C) includes a first pipe portion (11) having a first pipe end portion (15) to which the first fluid member (F1) is connected, a second pipe portion (12) having one end connected to the first pipe portion (11) and the other end connected to the second fluid member (F2), and a covering member (R) covering at least a part of the second pipe portion (12), the covering member (R) has a first covering end portion (R1) which is an end portion on the first pipe portion (11) side in the axial direction of the first pipe portion (11), and a second covering end portion (R2) which is an end portion opposite to the first covering end portion (R1) in the axial direction, the shortest distance L1 between the first covering end portion (R1) and the first pipe end portion (15) is larger than the shortest distance L2 between the first covering end portion (R1) and the second covering end portion (R2), a step of disposing the connection pipe (C) between the first fluid member (F1) and the second fluid member (F2), and a step of brazing one end portion of the connection pipe (C) and one end portion of the first fluid member (F1), and brazing the other end portion of the connection pipe (C) and one end portion of the second fluid member (F2). Connection method of the connection pipe.

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