Heat exchanger

Abstract

 [OBJECT] To provide a heat exchanger having a connector configured rationally.
[SOLVING MEANS] A connector 400 is comprised of a block body 410 and a pipe body 420, the block body has a flow passage 411 for flowing a medium and a joint surface 412 to be bonded to a tank 300a, a flow passage in the block body has a first opening 411a on the side of an external pipe 10 and a second opening 411b on the side of the tank, the second opening is located at the joint surface, and the pipe body is a member which has a brazing material clad on its outer periphery, disposed so that its one end is inserted through a hole 325 of the tank and the other end is located within the flow passage of the block body, and brazed to the hole of the tank and the flow passage of the block body with a brazing material which is clad on the outer periphery of the pipe body. Further, it is configured so that the pipe body is inserted from the second opening until its leading end hits against a part where the sectional shape of the flow passage of the block body changes, thereby restricting an inserted amount into the flow passage of the block body.

Description

[TECHNICAL FIELD]

[0001] The present invention relates to a heat exchanger which is comprised of tubes for flowing a medium, tanks to which the ends of the tubes are connected, and connectors disposed on the tanks, and has an external pipe for flowing in or out the medium connected to the connectors.

[BACKGROUND ART]

[0002] It is known that a heat exchanger such as a radiator or an evaporator used for a refrigeration cycle is configured by alternately stacking a plurality of flat tubes and corrugated fins to form a core, and connecting the ends of the tubes to tanks. A refrigerant is introduced into the inside through a connector disposed on the tank, flowed through the tubes while performing heat exchange with heat conducted to the core and discharged to the outside from the tank. This type of heat exchanger is produced by assembling individual component members and brazing the assembly in a furnace. Structures of the connectors disposed on the tanks are disclosed in Patent Documents 1 through 8

[Patent Document 1]

[0003] Japanese Patent Laid-Open Publication No. Hei 9-159317

[Patent Document 2]

[0004] Japanese Patent Laid-Open Publication No. Hei 9-280777

[Patent Document 3]

[0005] Japanese Patent Laid-Open Publication No. Hei 11-325755

[Patent Document 4]

[0006] Japanese Patent Laid-Open Publication No. 2000-274880

[Patent Document 5]

[0007] Japanese Patent Laid-Open Publication No. 2002-206889

[Patent Document 6]

[0008] Japanese Patent Laid-Open Publication No. 2002-228387

[Patent Document 7]

[0009] Japanese Patent Laid-Open Publication No. 2003-314988

[Patent Document 8]

[0010] Pamphlet of (PCT) International Publication No. 00/29794

[DISCLOSURE OF THE INVENTION]

[PROBLEMS TO BE SOLVED BY THE INVENTION]

[0011] For the heat exchanger, significant objects include the improvement of a heat exchange efficiency of a medium, miniaturization, weight reduction, facilitation of the production, saving of an installation space, and the like, and its connector is also demanded to have a more outstanding structure on the basis of the above objects. Especially, the connector structure is important to facilitate the production of the heat exchanger.

[0012] As the refrigerant for the refrigeration cycle, chlorofluorocarbon-based refrigerants including alternatives for chlorofluorocarbon have been used extensively but tend to be changed to CO₂ in consideration of the global environment in these years. In comparison with the refrigeration cycle using the chlorofluorocarbon-based refrigerant, a refrigeration cycle using CO₂ as the refrigerant has a considerably high inside pressure, and especially the pressure on a high-pressure side exceeds the critical point of the refrigerant depending on the use conditions such as a temperature. The critical point is a limit on the high-pressure side in a state that a gas layer and a liquid layer coexist (namely, a limit on the high-temperature side) and a terminal point at one end of a vapor pressure curve. A pressure, a temperature and a density at the critical point become a critical pressure, a critical temperature, and a critical density. Especially, in the radiator which is a high-temperature heat source of the refrigeration cycle, if the pressure exceeds the critical point of the refrigerant the refrigerant does not condense. The heat exchanger of such a supercritical refrigeration cycle must be configured to have the volumes of the tubes and tanks made small and their thickness increased in order to secure the pressure resistance. And, the connector is also demanded to have further structural improvements according to the increase in thickness and the decrease in diameter of the tanks.

[0013] The present invention has been made in view of the above circumstances and its object is to provide a heat exchanger with its connectors configured rationally.

[MEANS FOR SOLVING THE PROBLEMS]

[0014] The invention recited in claim 1 is a heat exchanger, comprising tubes for flowing a medium, tanks to which the ends of the tubes are connected, and connectors disposed on the tanks, and having an external pipe for flowing in or out the medium connected to the connectors, wherein the heat exchanger is configured by assembling members, which constitute the tubes, the tanks and the connectors, and brazing the assembly in a furnace; the tanks have a hole for communicating with the connectors; the connectors are comprised of a block body and a pipe body; the block body has a flow passage for flowing the medium and a joint surface for connection to the tank; the flow passage in the block body has a first opening on the side of the external pipe and a second opening on the side of the tank, and the second opening is located at the joint surface; and the pipe body is so disposed that one end thereof is inserted through the hole of the tank and the other end is located within the flow passage in the block body, and it is brazed with the hole of the tank and the flow passage of the block body with a brazing material which is disposed between the outer periphery of the pipe body and the tank's hole and the block body's flow passage.

[0015] The invention recited in claim 2 is the heat exchanger according to claim 1, wherein the pipe body is caulked to assemble the block body with the tank.

[0016] The invention recited in claim 3 is the heat exchanger according to claim 1 or 2, wherein the pipe body is a member having a brazing material clad on its outer periphery.

[0017] The invention recited in claim 4 is the heat exchanger according to any of claims 1 through 3, wherein the tank and the joint surface of the block body are brazed with a sheet form brazing material disposed between them.

[0018] The invention recited in claim 5 is the heat exchanger according to any of claims 1 through 3, wherein the tank and the joint surface of the block body are brazed with a paste form brazing material disposed between them.

[0019] The invention recited in claim 6 is the heat exchanger according to any of claims 1 through 5, wherein the flow passage of the block body has different shapes in the first opening and the second opening, and a sectional shape changes at a part between the first opening and the second opening; and the pipe body is inserted from the second opening until its leading end hits against the part where the sectional shape changes, thereby to restrict an inserted amount of the block body into the flow passage.

[0020] The invention recited in claim 7 is the heat exchanger according to claim 6, wherein the hole of the tank is a long hole, the second opening of the flow passage in the block body has the same shape as the long hole, and the pipe body is a flat type according to the long hole.

[0021] The invention recited in claim 8 is a heat exchanger, comprising tubes for flowing a medium, tanks to which the ends of the tubes are connected, and connectors disposed on the tanks, and having an external pipe for flowing in or out the medium connected to the connectors, wherein the tanks have a hole for communicating with the connectors; the connectors are comprised of a block body and a pipe body; the block body has a flow passage for flowing the medium and a joint surface for connection to the tank; the flow passage in the block body has a first opening on the side of the external pipe and a second opening on the side of the tank, the second opening is located at the joint surface, the first opening and the second opening have different shapes, and a sectional shape changes at a part between the first opening and the second opening; the pipe body is so disposed that one end thereof is inserted through the hole of the tank and the other end is located within the flow passage in the block body; and the pipe body is inserted from the second opening until its leading end hits against the part where the sectional shape changes thereby to restrict an inserted amount of the block body into the flow passage.

[0022] The invention recited in claim 9 is the heat exchanger according to claim 8, wherein the hole of the tank is a long hole, the first opening of the flow passage in the block body has the same shape as the long hole, and the pipe body is a flat type according to the long hole.

[0023] The invention described in claim 10 is the heat exchanger according to any of claims 1 through 9, wherein it is used for a refrigeration cycle having a pressure on a high pressure side exceeding the critical point of the refrigerant.

[EFFECTS OF THE INVENTION]

[0024] According to the present invention, a heat exchanger having a connector configured rationally can be obtained.

[BRIEF DESCRIPTION OF THE DRAWINGS]

[0025] 

Fig. 1 is an explanatory diagram showing a refrigeration cycle according to an embodiment of the present invention.

Fig. 2 is an explanatory diagram showing an overview of a heat exchanger according to an embodiment of the present invention.

Fig. 3 is a front sectional diagram showing a main portion of the heat exchanger according to an embodiment of the present invention.

Fig. 4 is a top plan view showing the heat exchanger according to the embodiment of the present invention.

Fig. 5 shows a first tank according to an embodiment of the present invention, where (a) is a top plan view showing a first tank member, (b) is a front view showing the first tank member, (c) is a top plan view showing a second tank member, (d) is a front view showing the second tank member, (e) is a top plan view showing a closure member, and (f) is a front view showing the closure member.

Fig. 6 shows a second tank according to an embodiment of the present invention, where (a) is a top plan view showing a first tank member, (b) is a front view showing the first tank member, (c) is a top plan view showing a second tank member, (d) is a front view showing the second tank member, (e) is a top plan view showing a closure member, and (f) is a front view showing the closure member.

Fig. 7 is a side sectional view showing a first connector in a state that an external pipe for flowing a refrigerant is connected according to an embodiment of the present invention.

Fig. 8 is a side sectional view showing the first connector in a state that the external pipe for flowing a refrigerant is disconnected according to the embodiment of the present invention.

Fig. 9 is a top sectional view showing the first connector in a state that the external pipe for flowing a refrigerant is connected according to the embodiment of the present invention.

Fig. 10 is a top sectional view showing the first connector in a state that the external pipe for flowing a refrigerant is disconnected according to the embodiment of the present invention.

Fig. 11 is an explanatory diagram of a block body constituting the first connector according to the embodiment of the present invention, where (a) is a top plan view showing the block body, (b) is a front view showing the block body, (c) is a side view showing the block body, and (d) is a back view showing the block body.

Fig. 12 is an explanatory diagram of a pipe body constituting the first connector according to an embodiment of the present invention, where (a) is a top plan view showing the pipe body, (b) is a front view showing the pipe body, and (c) is a side view of the pipe body.

Fig. 13 is an explanatory diagram of a process of caulking the pipe body according to an embodiment of the present invention.

Fig. 14 is an explanatory diagram of a process of caulking the pipe body according to the embodiment of the present invention.

[BEST MODE FOR CARRYING OUT THE INVENTION]

[0026] Embodiments of the present invention will be described with reference to the drawings. A refrigeration cycle 1 shown in Fig. 1 is a refrigeration cycle for air-conditioning of a car interior mounted on an automobile and provided with a compressor 2 for compressing a refrigerant, a radiator 100 for cooling the refrigerant compressed by the compressor 2, an expansion valve 3 for expanding the refrigerant by reducing the pressure of the refrigerant which is cooled by the radiator 100, an evaporator 4 for evaporating the refrigerant decompressed by the expansion valve 3, an accumulator 5 for separating the refrigerant flowing out from the evaporator 4 into a gas layer and a liquid layer and allowing the gas layer refrigerant to flow to the compressor 2, and an inner heat exchanger 6 for performing heat exchange between a high-pressure side refrigerant and a low-pressure side refrigerant to improve the cycle efficiency. As the refrigerant, CO₂ is used, and the pressure on the high-pressure side of the supercritical refrigeration cycle 1 exceeds the critical point of the refrigerant depending on the use conditions such as a temperature and the like. The arrow in Fig. 1 indicates a direction in which the refrigerant is circulated.

[0027] As shown in Fig. 2 through Fig. 4, the radiator 100 which is the heat exchanger of this embodiment is provided with a first core 200a and a second core 200b which are configured by alternately stacking flat tubes 210 and corrugated fins 220 for flowing the refrigerant (namely, the medium), a first tank 300a, a second tank 300b and a third tank 300c into which the ends of the individual tubes 210 are inserted for connection, a first connector 400 which is disposed on the first tank 300a as an inlet for the refrigerant, and a second connector 500 which is disposed on the third tank 300c as an outlet for the refrigerant. The individual tanks 300a, 300b, 300c are tubes which have the top and bottom ends sealed with a closure member 330. A reinforcing member 600 is disposed on the top and bottom ends of the first core 200a and the second core 200b in their stacked direction. The reinforcing member 600 extends over the first core 200a and the second core 200b, and the ends of the reinforcing member 600 are supported by the tanks 300a, 300b, 300c.

[0028] The refrigerant which is sent out from the compressor 2 is flowing in to the first connector 400. The refrigerant flows out from the second connector 500 is sent out to the expansion valve 3. Arrows in Fig. 2 indicate the flowing directions of the refrigerant in the radiator 100, and a white arrow mark indicates an air blowing direction to the first core 200a and the second core 200b.

[0029] One ends of the tubes 210 of the first core 200a are connected to the first tank 300a. The other ends of the tubes 210 of the first core 200a and one ends of the tubes 210 of the second core 200b are connected to the second tank 300b. Further, the other ends of the tubes 210 of the second core 200b are connected to the third tank 300c.

[0030] Then, air flows to the first core 200a and the second core 200b by a fan (not shown), and the refrigerant performs heat exchange with heat conducted to the first core 200a and the second core 200b. Further, the first core 200a and the second core 200b are stacked in the air flow direction, and configured so that the flat surfaces of the tubes 210 are parallel with the air flow direction. The air flow is caused from the side of the second core 200b. In other words, the radiator 100 of this embodiment is a counter flow type heat exchanger wherein a flow of the refrigerant in the first core 200a and the second core 200b is made counter-flow.

[0031] The radiator 100 is produced by integrally assembling a plurality of aluminum alloy members which constitute the tubes 210, the fins 220, the first tank 300a, the second tank 300b, the third tank 300c, the first connector 400, the second connector 500, and the reinforcing members 600 and brazing the assembled body in a furnace. Further, for this brazing in the furnace, a brazing material and flux required for brazing are disposed on required potions of the respective members.

[0032] The tubes 210 of this embodiment are aluminum alloy extrusion-molded tubes or roll-formed tubes having a plurality of flow passages. Further, the ends of the tubes 210 are subjected to a plastic deformation processing and twisted in a prescribed direction. Specifically, both ends of the tubes 210 in the breadth direction are twisted by 90° with respect to the air flow direction.

[0033] As shown in Fig. 5, the first tank 300a is comprised of a first tank member 310 and a second tank member 320 which are mutually assembled to form a tube and closure members 330 which close the space between the first tank member 310 and the second tank member 320. Tube insertion holes 311, in which the ends of the tubes 210 are inserted, are formed in a line at prescribed intervals in a longitudinal direction of the first tank member 310. And, reinforcing member insertion holes 312, in which the ends of the reinforcing members 600 are inserted, are disposed at both ends in the longitudinal direction. The tube insertion holes 311 and the reinforcing member insertion holes 312 are aligned their major axes in the longitudinal direction of the first tank 300a. This is a structure to comply with the decrease in the diameter of the first tank 300a to secure the compression strength. Besides, the second tank members 320 are provided in the longitudinal direction with end face joint surfaces 321 which bond end faces of the first tank member 310, ribs 322 which position the first tank member 310, and bending portions 323 which are bent after the first tank member 310 is positioned. The first tank member 310 is held by the second tank member 320 by bending the bending portions 323. And, fitting portions 324 for fitting the closure member 330 are disposed at required portions of the second tank member 320. The closure member 330 is a plate having an edge which meets the inner peripheries of the first tank member 310 and the second tank member 320, and the first tank member and the second tank member are assembled with the closure members 330 between them. The closure member 330 is disposed between tube insertion hole 311 and the reinforcing member insertion hole 312 of the first tank member 310. The bending portions 323 are bent along the overall length of the second tank member 320 in its longitudinal direction. Otherwise, it may be bent partly. The ends of the tubes 210 and the ends of the reinforcing members 600 are inserted into the tube insertion holes 311 before or after the first tank member 310 and the second tank member 320 are assembled. By the above-described brazing in the furnace, the ends of the tubes 210 and the tube insertion holes 311, the ends of the reinforcing members 600 and the reinforcing member insertion holes 312, and the end faces of the first tank member 310 and the end face joint surfaces 321 of the second tank member 320 are brazed. The third tank 300c has the same structure as that of the first tank 300a.

[0034] Meanwhile, as shown in Fig. 6, the second tank 300b also has the first tank member 310 and the second tank member 320 which form a tube when assembled mutually, and the closure members 330 which close the space between the first tank member 310 and the second tank member 320. The tube insertion holes 311 in which the ends of the tubes 210 are inserted are formed in two lines at prescribed intervals in the longitudinal direction of the first tank member 310. The other structure is the same as the first tank 300a.

[0035] Besides, the first tank 300a is provided with the first connector 400, and the third tank 300c is provided with the second connector 500. Holes are formed in required portions of the first tank 300a and the third tank 300c for communication with the connectors 400, 500.

[0036] Then, the first connector 400 will be described. Fig. 7 is a side sectional view showing the first connector 400 in a state that an external pipe 10 for flowing a refrigerant is connected, and Fig. 8 is a side sectional view showing the first connector 400 in a state that the external pipe 10 is disconnected. Fig. 9 is a top sectional view showing the first connector 400 in a state that the external pipe 10 is connected, and Fig. 10 is a top sectional view showing the first connector 400 in a state that the external pipe 10 is disconnected. Fig. 11 is an explanatory view of a block body constituting the first connector 400, and Fig. 12 is an explanatory view of a pipe body constituting the first connector. The second connector 500 is used to connect the external pipe for flowing out the refrigerant, and its basic structure is the same as the first connector 400, so that its description is omitted.

[0037] The first connector 400 of this embodiment is formed by brazing a block body 410 and a pipe body 420. A hole 325 for communicating with the first connector 400 is formed in a required portion of the second tank member 320.

[0038] In this embodiment, the block body 410 is formed by fabricating an extrusion member having a prescribed shape and provided with a flow passage 411 for flowing the medium and a joint surface 412 which is bonded to a second tank member 320 of the first tank 300a. The illustrated joint surface 412 has a curved surface on the outer surface of the second tank member 320 for externally fitting. And, the flow passage 411 of the block body 410 of this embodiment is formed by cutting in a required portion of an extrusion member, and configured to have a first opening 411a on the side of the external pipe 10 and a second opening 411b on the side of the first tank 300a with the second opening 411b positioned on the joint surface 412.

[0039] In this embodiment, the pipe body 420 is a member of which outer periphery is clad with a brazing material. Specifically, it is formed by rolling a brazing sheet which has its one surface clad with a brazing material. This pipe body 420 is disposed so that one end is inserted through the hole 325 and the other end is positioned within the flow passage 411 of the block body 410. And, it is brazed to the hole 325 and the flow passage 411 with the brazing material which is clad on the outer periphery of the pipe body 420.

[0040] The second tank member 320 of the first tank 300a and the joint surface 412 of the block body 410 are brazed with a sheet form brazing material disposed between them. Otherwise, they are brazed with a paste form brazing material disposed between them. By the above-described brazing in the furnace, the pipe body 420 and the hole 325 of the second tank member 320, the pipe body 420 and the flow passage 411 of the block body 410, and the outer surface of the second tank member and the joint surface 412 of the block body 410 are brazed. By configuring in this way, the block body 410, the pipe body 420, and the second tank member 320 can be brazed efficiently. The pipe body 420 is a member used to efficiently dispose the block body 410 in the hole 325, and it is not required to secure the compression strength by itself. In other words, a thin member can be used as the pipe body 420. In this embodiment, a brazing sheet configuring the pipe body 420 has a thickness of 0.5 to 1.0 mm.

[0041] The flow passage 411 of the block body 410 of this embodiment has different shapes between the first opening 411a and the second opening 411b and different sectional shapes between the first opening 411a and the second opening 411b. This flow passage 411 is formed by cutting from both sides of the first opening 411a and the second opening 411b.

[0042] The pipe body 420 is inserted from the second opening 411b until its leading end hits against a part where the sectional shapes of the flow passage 411 of the block body 410 change, thereby restricting an inserted amount of the block body 410 into the flow passage 411. In this embodiment, the hole 325 formed in the second tank member 320 of the first tank 300a is a long hole. The major axis of the long hole is aligned with the longitudinal direction of the first tank 300a. In other words, it is configured according to the miniaturization of the diameter of the first tank 300a in line with the assurance of securing the compression strength. The second opening 411b of the flow passage 411 in the block body 410 has the same shape as the long hole, and the pipe body 420 is a flat type according to the long hole. Meanwhile, the first opening 411a is round. It is configured such that both ends of the pipe body 420 in the flat direction hit against the part where the sectional shape of the flow passage 411 of the block body 410 changes. By configuring in this way, the block body 410 and the pipe body 420 can be assembled easily and accurately, and the brazing reliability can also be improved surely.

[0043] The external pipe 10 is provided with a pipe-side block body 11 at its forward end. The pipe-side block body 11 has a flow passage 12 for flowing the medium and a projection 13 which is inserted into the first opening 411a of the flow passage 411 in the block body 410. The mouth of the flow passage 12 of the pipe-side block body 11 is located at the leading end of the projection 13. The projection 13 is fitted with an O-ring 14 as sealing means. The connector 400 and the external pipe 10 are connected by fixing the block body 410 and the pipe-side block body 11 with a bolt 15. The block body 410 and the pipe-side block body 11 are respecting provided with a female thread 413 with which the bolt 15 is threaded, and a through hole 16 through which the bolt 15 is inserted.

[0044] The block body 410 and the tank member 320 may be assembled by caulking the pipe body 420. As shown in Fig. 13, after the block body 410 and the pipe body 420 have been assembled, a first jig A is inserted through the first opening 411a, and one end of the pipe body 420 is expanded partly or wholly. Then, as shown in Fig. 14, after the second tank member 320 has been assembled, a second jig B is inserted between the ribs 332 of the second tank member 320 to expand partly or wholly the other end of the pipe body 420. By configuring in this way, the first tank 30Qa and the first connector 400 can be assembled easily. Generally, where the connector is to be brazed, its component members are temporarily fixed by argon welding or the like, but it has a disadvantage that the welding cost is high. In this respect, the present embodiment has an advantage that temporary fixing can be made without welding.

[0045] The radiator 100 of this embodiment is configured by securing the required pressure resistance depending on the refrigerant which falls in a supercritical state and rationalizing the connectors 400, 500 according to the miniaturization of the diameters of the individual tanks 300a, 300b, 300c, and can be used very suitably as the heat exchanger of the supercritical refrigeration cycle 1 to be mounted on an automobile. And, it is to be understood that the structure of the individual parts of this embodiment can be modified appropriately within the technical scope recited in the claims and not limited to the drawings and descriptions. The structures of the connectors 400, 500 can also be applied to other heat exchangers such as the evaporator 4, the inner heat exchanger 6 and the like. It can also be applied to a radiator and a heater core of an automobile.

[INDUSTRIAL APPLICABILITY]

[0046] The heat exchanger of the present invention can be used suitably as a radiator of a refrigeration cycle, an evaporator, an inner heat exchanger, and a radiator, and a heater core of an automobile.

[DESCRIPTION OF REFERENCE NUMERALS]

[0047] 

1

Refrigeration cycle

2

Compressor

3

Expansion valve

4

Evaporator

5

Accumulator

6

Inner heat exchanger

10

External pipe

11

Pipe-side block body

12

Flow passage in pipe-side block body

13

Projection

14

O-ring

15

Bolt

16

Through hole

100

Radiator

200a

First core

200b

Second core

210

Tube

220

Fin

300a

First tank

300b

Second tank

300c

Third tank

310

First tank member

311

Tube insertion hole

312

Reinforcing member insertion hole

313

Fitting portion

320

Second tank member

321

End face joint surface

322

Rib

323

Bending portion

324

Fitting portion

325

Hole

330

Closure member

400

First connector

410

Block body

411

Flow passage of block body

411a

First opening

411b

Second opening

412

Joint surface

413

Female thread

420

Pipe body

500

Second connector

600

Reinforcing member

A

First jig

B

Second jig

Claims

1. A heat exchanger, comprising tubes for flowing a medium, tanks to which the ends of the tubes are connected, and connectors disposed on the tanks, and having an external pipe for flowing in or out the medium connected to the connectors, wherein:

the heat exchanger is configured by assembling members, which constitute the tubes, the tanks and the connectors, and brazing the assembly in a furnace;

the tanks have a hole for communicating with the connectors;

the connectors are comprised of a block body and a pipe body;

the block body has a flow passage for flowing the medium and a joint surface for connection to the tank;

the flow passage in the block body has a first opening on the side of the external pipe and a second opening on the side of the tank, and the second opening is located at the joint surface; and

the pipe body is so disposed that one end thereof is inserted through the hole of the tank and the other end is located within the flow passage in the block body, and it is brazed with the hole of the tank and the flow passage of the block body with a brazing material which is disposed between the outer periphery of the pipe body and the tank's hole and the block body's flow passage.

2. The heat exchanger according to claim 1, wherein the pipe body is caulked to assemble the block body with the tank.

3. The heat exchanger according to claim 1 or 2, wherein the pipe body is a member having a brazing material clad on its outer periphery.

4. The heat exchanger according to any of claims 1 through 3, wherein the tank and the joint surface of the block body are brazed with a sheet form brazing material disposed between them.

5. The heat exchanger according to any of claims 1 through 3, wherein the tank and the joint surface of the block body are brazed with a paste form brazing material disposed between them.

6. The heat exchanger according to any of claims 1 through 5, wherein:

the flow passage of the block body has different shapes in the first opening and the second opening, and a sectional shape changes at a part between the first opening and the second opening; and

the pipe body is inserted from the second opening until its leading end hits against the part where the sectional shape changes,thereby to restrict an inserted amount of the block body into the flow passage.

7. The heat exchanger according to claim 6, wherein the hole of the tank is a long hole, the second opening of the flow passage in the block body has the same shape as the long hole, and the pipe body is a flat type according to the long hole.

8. A heat exchanger, comprising tubes for flowing a medium, tanks to which the ends of the tubes are connected, and connectors disposed on the tanks, and having an external pipe for flowing in or out the medium connected to the connectors, wherein:

the tanks have a hole for communicating with the connectors;

the connectors are comprised of a block body and a pipe body;

the block body has a flow passage for flowing the medium and a joint surface for connection to the tank;

the flow passage in the block body has a first opening on the side of the external pipe and a second opening on the side of the tank, the second opening is located at the joint surface, the first opening and the second opening have different shapes, and a sectional shape changes at a part between the first opening and the second opening;

the pipe body is so disposed that one end thereof is inserted through the hole of the tank and the other end is located within the flow passage in the block body; and

the pipe body is inserted from the second opening until its leading end hits against the part where the sectional shape changes thereby to restrict an inserted amount of the block body into the flow passage.

9. The heat exchanger according to claim 8, wherein the hole of the tank is a long hole, the first opening of the flow passage in the block body has the same shape as the long hole, and the pipe body is a flat type according to the long hole.

10. The heat exchanger according to any of claims 1 through 9, wherein it is used for a refrigeration cycle having a pressure on a high pressure side exceeding the critical point of the refrigerant.

Drawing