JPH10246588A - Method for jointing tube and fin of integral heat-exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an excellent jointing method of radiator tube and fin at the time of manufacturing a heat-exchanger where a radiator core and a condenser core are integrated. SOLUTION: In the jointing method of a heat-exchanger having integral structure of radiator core 10 and a condenser core 20, radiator tubes 11 comprise brazing tubes produced by cladding the outer surface of an Al alloy core material with an Al-Si based brazing filler metal containing 2-6.5wt.% of Si and condenser tubes 21 comprises extruded multi-hole flat tubes of Al or Al alloy. Fins 31 comprises brazing sheet fins produced by cladding the opposite sides of an Al or Al alloy core material with an Al-Si based brazing filler metal containing 7-11wt.% of Si. The radiator tubes 11, the condenser tubes 21 and the fins 31 are jointed integrally by brazing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiator tube, a condenser tube, and a fin of a so-called integrated heat exchanger in which a radiator core and a condenser core are integrated with each other. More particularly, the present invention relates to an improved method of joining a radiator tube and a fin.

[0002]

2. Description of the Related Art Conventionally, heat exchangers mounted on automobiles are:
Various types such as a radiator for cooling an engine, a condenser and an evaporator for air conditioning, an oil cooler for cooling oil, or an intercooler are used.

FIG. 8 shows an example of a radiator. In the figure, 1a is a radiator tube and 1b is a fin.
The material composition of the tube 1a of the radiator 1 is such that an aluminum alloy core material (3003 or the like, Al-Mn, Anode material (7072, Al-Zn-based alloy material) is clad on the inner surface of the base material, and brazing material (4343, 4045, etc., Al-Si-based alloy) for brazing bare fins on the outer surface. In general, a brazing sheet (having a thickness of, for example, 0.2 mm to 0.3 mm) on which a material (material) is clad is formed, which is subjected to an electric resistance welding process to be used as the tube 1a. The cladding rate of this brazing material is 0.2 mm
It is about 10% for 0.3 mm. Also,
The fin 1b has a thickness of 0.
In general, bare Al or Al alloy fin material of about 1 mm is used.

FIG. 9 shows an example of a capacitor. In the figure, 2a is a condenser tube and 2b is a fin.
The condenser 2 is a condenser of a heat exchanger (condenser and evaporator) for performing air conditioning in the automobile, and a compressed refrigerant such as Freon passes through the inside of the tube 2a. Therefore, the internal pressure in the tube is high, and for the reason of strength and to ensure heat exchange, Al
Alternatively, an extruded flat multi-hole tube of an Al alloy is often used. The outer surface is usually used as a brazing-free bare tube because it is very difficult to coat the brazing material simultaneously when manufacturing extruded flat multi-hole tubes. For this reason, the manufacture of the capacitor core is generally performed by using a brazing material (4343, 4045, 4045) on the outer surface (both surfaces) of the Al or Al alloy core material.
4047 etc.), 1 per side
Brazing sheet fin 2b clad about 0%
(The thickness is, for example, about 0.1 mm) is generally used.

Generally, various types of heat exchangers having different functions are usually manufactured independently and mounted on automobiles. However, in recent years, such heat exchangers have been required to be compact, space-saving, and easy to manufacture. From this point, various types of so-called integrated heat exchangers in which two types of heat exchangers having different functions are integrally manufactured have been proposed (for example, Japanese Utility Model Application Laid-Open No. 56-167727, and Japanese Patent Application Laid-Open No. 1-24).
7990, Japanese Utility Model Laid-Open No. 2-68268,
88 etc.).

FIG. 7 shows an integrated heat exchanger in which a radiator core 1 and a condenser core 2 are disclosed in Japanese Utility Model Laid-Open Publication No. 2-68268. In the drawings, reference numerals 5 and 6 denote radiator headers, reference numerals 7 and 8 denote capacitor headers, reference numeral 30 denotes a fin extending over both tubes, and reference numeral 40 denotes an insert (reinforcing material) extending over both cores.

[0007] FIG. 6 is related to integrated heat exchanger and a radiator and a capacitor disclosed in JP-A-8-170888 is integral structure, radiator tubes ^1a, a condenser tubes ^2a, the brazing sheet ( (A sacrificial anode material on the inner surface of an Al alloy core material and a plate clad with a brazing material on the outer surface), and these two tubes and bare fins extending over both tubes are integrally brazed and joined.

As described above, in the integrated heat exchanger in which the radiator core and the condenser core are integrally formed, various studies have been made on the material constitution of the tubes and the fins and how to join them. In the case where a radiator core and a capacitor core are integrally formed by brazing an integrated heat exchanger, a tube having a brazing material on the outer surface manufactured by a brazing sheet is used for a radiator tube, and the outer surface is formed on the condenser tube. It is desirable to use a bare extruded multi-hole tube having no brazing material, and to join the fin materials to each other as fins (common to both cores) spanning both tubes. In this case, when a bare fin material adapted to a radiator tube made of a brazing sheet is used, the radiator tube and the fin can be joined, but the condenser tube made of an extruded flat multi-hole tube cannot be joined to the fin. In addition, if brazing sheet fins are used in accordance with the condenser tube, the brazing material in the radiator tube portion becomes excessive, so the brazing erosion of the R portion where the fin comes into contact with the tube becomes severe, and the radiator core collapses during brazing heating. There is a problem that a problem occurs.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to use a radiator tube made of a brazing sheet having a brazing sheet on the outer surface and having a brazing material on the outer surface, and a condenser tube having a flat and extruded bare material having no brazing material on the outer surface. In the case where a radiator core and a condenser core are integrally formed by brazing using a hole tube, it is to find a good joining method between these tubes and the fins, especially a radiator tube. Is to find the optimum brazing material composition and cladding ratio on the outer surface of the steel.

[0010]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems by optimizing the composition of the brazing material used for the radiator tube or the amount of brazing to be clad, thereby producing a sound integrated heat exchanger. Is made possible. That is,
The invention according to claim 1 for solving the above-mentioned problem is directed to a radiator tube (1) in an integrated heat exchanger in which a radiator core ( 10 ) and a condenser core ( 20 ) are integrated.
1) and a method of joining a condenser tube (21) and a fin (31) straddling both tubes, wherein the radiator tube (11) is provided on the outer surface of the Al alloy core material by 2 to
The capacitor tube (21) is made of an Al or Al alloy extruded flat multi-hole tube, and the fin (31) is made of Al. The Al-Si brazing material clad with 6.5 wt% of Si is clad. Or Al-S containing 7 to 11 wt% Si on both surfaces of an Al alloy core material
a brazing sheet fin material clad with an i-type brazing material, wherein the radiator tube (11), the condenser tube (21) and the fin (31) are integrally brazed and joined. It is a method of joining the tube and the fin,

Further, the invention according to claim 2 provides a radiator tube (11), a condenser tube (21) and both tubes in an integrated heat exchanger in which a radiator core ( 10 ) and a condenser core ( 20 ) are integrated. A method of joining with a spanning fin (31), wherein a radiator tube (11) is formed by coating an Al-Si brazing material containing 7 to 11 wt% of Si on the outer surface of an Al alloy core material with a cladding ratio of 2 to 5.
%, The condenser tube (21) is made of an Al or Al alloy extruded flat multi-hole tube, and the fin (31) is made of Al or A
A containing 7-11% by weight of Si on both sides of a l-alloy core material
a brazing sheet fin material clad with an l-Si brazing material, wherein the radiator tube (11) and the condenser tube (21) and the fin (31) are integrally brazed and joined. This is a method of joining tubes and fins of the exchanger.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

(1) Regarding the Invention of Claim 1 The details of the invention of claim 1 are as described above, but the present invention will be described with reference to the drawings for easy understanding. FIG.
FIG. 1 is a perspective view showing an example of the structure of an integrated heat exchanger according to the present invention, including a partially cut-away view. The present invention
As shown in FIG. 1, in the joint of the radiator tube 11 and the condenser tube 21 with the fins 31 spanning both tubes in the integrated heat exchanger having the radiator core 10 and the condenser core 20 integrated, the radiator tube 11 is made of aluminum. 2 to 6.5 w on the outer surface of the alloy core material
A brazing tube material clad with an Al-Si brazing material containing t% Si is used, the condenser tube 21 is an Al or Al alloy extruded flat multi-hole tube, and the fin 31 is an Al or Al alloy core. 7 on both sides of the material
This is a joining method in which a brazing sheet fin material clad with an Al-Si-based brazing material containing up to 11 wt% of Si is brazed and joined together. In addition,
FIG. 2 is an enlarged perspective view showing a joint state between the condenser tube 21, the radiator tube 11 and the fins 31 in FIG. 1, and FIGS. 3 and 4 respectively show a joint state between the radiator tube 11 and the fins 31 in FIG. FIG. 2 is an enlarged perspective view and an enlarged cross-sectional view. In FIG. 4, 31R is an R portion of the fin, and 11d is a fillet portion.

Here, the extruded flat multi-hole tube to be the condenser tube 21 and the brazing sheet fin material to be the fins 31 are conventionally known materials, but the brazing tube material to be the radiator tube 11 is as follows. This is the most characteristic feature of the joining method of the present invention for joining these three members.

Radiator tube 11 of the present invention
Uses a brazing tube material in which an Al-Si brazing material containing 2 to 6.5 wt% of Si is clad on the outer surface of an Al alloy core material. That is, the Al-Si-based brazing material has a lower Si content and a range of 2 to 6.5 w compared to a normal brazing material (Al-7 to 11 wt% Si alloy).
The melting point of the Al—Si alloy was raised to t% to suppress the function as a brazing material. Conventional radiator tube material is usually 7 to 11 wt% on the outer surface of Al alloy core material.
Al-Si alloy brazing containing about Si is clad at a cladding ratio of about 10%. When this tube material is used in combination with a normal brazing fin in an integrated heat exchanger, the brazing sheet fin side has the same brazing. Therefore, at the time of brazing, the R portion where the fin is joined to the radiator tube (FIG. 4) 31R part, 11d part)
In addition, there is a problem that the fins are eroded by the excess braze because the excess braze is supplied. In the present invention, by reducing the amount of Si in the supplied brazing material, the excess brazing during brazing is made to have a higher melting point than in the past, thereby suppressing the function as a brazing material. It reduces erosion.

The reason why the amount of Si in the brazing filler metal on the outer surface of the radiator tube in the present invention is limited to 2 to 6.5 wt% is as follows.
If the amount of i is less than 2 wt%, the brazing of the connection between the radiator tube and the header plate (not shown) of the headers 12 and 13 may be poor, and
If the amount exceeds 6.5 wt%, the melting point of the brazing material will decrease due to an increase in the amount of Si, and there will be a problem of brazing erosion of the R portion (31R portion, 11d portion in FIG. 4) of the brazing sheet fin. In the present invention, the cladding ratio of the brazing material on the outer surface of the radiator tube is preferably set to 8 to 13%.

The capacitor tube 21 of the present invention is usually an extruded flat multi-hole tube made of Al or an Al alloy having no brazing material on the outer surface. Specific materials are, for example, pure Al-based 1050, 1100, etc., Al-M
and n-type 3003, 3203, and the like. As the fins 31 in the present invention, ordinary brazing sheet fins are used, and this material is usually made of Al or Al alloy core material on both surfaces of Al-7 to 11 wt% Si alloy brazing, but 8 to 12%.
The degree is clad. This core material is, for example, Al-M
Pure Al-based materials such as n-based 3003 and 3203.
The brazing alloy material is, for example, 4343 (Al-6.8 to Al-6.8).
8.2 wt% Si alloy), 4045 (Al-9.0-1)
1.0 wt% Si alloy).

The radiator tube 11, the condenser tube 21, and the fins 31 having the above-described configuration are combined and brazed under normal brazing (brazing) conditions, so that these three members are integrally and well brazed. be able to. The radiator tube 1 shown in FIG.
1. Each condenser tube 21 is not limited to one.
There may be a plurality (two, three, etc.) as necessary. FIG. 2 is an enlarged view showing a state where the radiator tube 11 and the condenser tube 21 are connected to the fin 31 in the case of one each.

(2) Regarding the invention of claim 2 The invention of claim 2 is directed to a radiator tube (11) and a condenser tube (11) in an integrated heat exchanger in which a radiator core ( 10 ) and a condenser core ( 20 ) are integrated. 21) and a fin (31) spanning both tubes, the radiator tube (11) has an outer surface of an Al alloy core material containing 7-11% by weight of Al—containing Si.
A brazing tube material in which a Si-based brazing material is clad at a cladding ratio of 2 to 5% is used, and a condenser tube (21) is an Al or Al alloy extruded flat multi-hole tube,
Further, fins (31) are provided on both sides of the Al or Al alloy core material.
This is a joining method in which a brazing sheet fin material clad with an Al-Si-based brazing material containing up to 11 wt% of Si is brazed and joined together. That is,
The most characteristic feature of the present invention is that the brazing material of the brazing tube material to be the radiator tube 11 is as follows.
The brazing alloy composition is an ordinary composition (containing 7 to 11% of Si), and its cladding ratio is set to 2 to 5% by making it smaller than the conventional one (about 10%).

In the present invention, the cladding ratio of the brazing material on the outer surface of the radiator tube material is reduced, and the radiator tube 11 and the brazing sheet fin 31 are reduced during brazing.
Is reduced in the portions (31R and 11d portions in FIG. 4) in contact with each other, and the absolute amount of Al-Si-based brazing that erodes the fins 31 is reduced. The reason why the cladding ratio of the brazing material is limited to 2 to 5% is that if the brazing ratio is less than 2%, not only the joining of the radiator headers 12 and 13 with the header plate (not shown) is deteriorated, but also the brazing sheet for the tube. The material cannot be manufactured industrially. On the other hand, if the cladding ratio exceeds 5%, the amount of brazing that accumulates at the portions where the radiator tube 11 and the brazing sheet fin 31 are in contact (31R and 11d in FIG. 4) at the time of brazing increases, and the fin 31 due to brazing increases. This is because erosion becomes severe. The condenser tube 21 and the fin 31 used for the joining of the present invention are the same as those described in the first aspect of the present invention.

The structure of the brazing sheet material for the radiator tube in the first and second aspects of the present invention is shown in FIG.
(A) As shown in (b), the brazing material 11b is clad on the outer surface of the Al alloy core material 11a, and the sacrificial anode material 1 is formed on the inner surface.
1a is clad (a), and depending on the application, the brazing material 11b is clad on the outer surface of the Al alloy core material 11a and there is nothing on the inner surface (b). The sacrificial anode material 11c on the inner surface is for securing corrosion resistance inside the tube, and is usually made of Al-1wt% Zn, Al-4wt% Z.
An n-based or Al-In-Mg-based alloy material is used. Also,
When these sacrificial anode materials are not used on the inner surface of the tube, the quality of water passing through the radiator tube is well controlled (for example, when a corrosion inhibitor is added to water). Therefore, the presence or absence of the sacrificial anode material of the radiator tube material does not affect the present invention at all,
There is no particular limitation as long as the desired corrosion resistance can be designed.

[0021]

EXAMPLES Examples of the present invention (examples of the present invention) will be described below in more detail together with comparative examples. [Embodiment 1] This embodiment relates to claim 1. One surface of 3003 alloy core material (external surface of tube)
Then, as shown in Table 1, an Al alloy brazing material containing 1.8 to 7.0 wt% of Si was clad at a cladding ratio of 10 to 12%, and Al-4w was coated on the other surface (inside the tube).
A sacrificial anode material made of a t% Zn alloy was clad (cladding ratio: 10%) and combined to produce a brazing sheet (three-layer material) having a thickness of 0.3 mm for a radiator tube. Refining is H14.

[0022]

[Table 1]

In the above specific production, after casting the core material alloy,
Homogenize in the temperature range of 450-600 ° C,
After facing each 0 mm, hot rolling was performed together with the brazing alloy plate and the sacrificial layer alloy plate prepared in advance. In the process after the hot rolling, as usual, a predetermined thickness (0.3 mm) and temper (H14) were obtained by cold rolling and annealing. The obtained three-layer brazing sheet was subjected to an electric resistance welding process to obtain a radiator tube (11 in FIGS. 1 to 4). The dimensions of the radiator flat tube are 16 mm wide × 2 mm high.

Also, a condenser tube (FIG. 1) made of an ordinary extruded flat multi-hole tube (material 1050) formed by extrusion.
2) 21) were prepared. The dimensions of the extruded flat multi-hole tube are eight holes with a width of 16 mm, a height of 2 mm, and a wall thickness of 0.4 mm. Further, the core material is 3003, and a cladding (cladding ratio of 10%) of 4343 brazing material on both surfaces thereof has a thickness of 0.1.
mm fin brazing sheet (temper H14) was produced, slitted to a width of 40 mm, and further corrugated to form fins (31 in FIGS. 1-4).

The radiator tube 11, the condenser tube 21 and the corrugated fin 31 are assembled as shown in FIG. 2 (one radiator tube 11 and one condenser tube 21 are placed one above the other, and the corrugated fin 31 is arranged between them). A test core was assembled so that the radiator core and the capacitor core were integrated.

Next, 10 g / m ² of a non-corrosive flux (mixed flux of KAlF ₄ and K ₂ AlF ₅ ) was applied to the test assembly core, and the flux was applied in a nitrogen gas atmosphere.
A test product was obtained by performing brazing and heating at 05 ° C. for 3 minutes.
The soundness of this test product was evaluated by observing the brazed state and the joined state of the R portion of the fin material (31R portion in FIG. 4). Table 2 shows the evaluation results.

[0027]

[Table 2]

As is clear from Table 2, the bonding method satisfying the requirements of the present invention (Examples Nos. 1 to 4) has a high soundness ratio of the fin R portion of the radiator core portion and the fin of the radiator core portion. It can be seen that the bonding ratio of the is also high. In addition,
There is no problem in joining the fins of the capacitor core. On the other hand, a bonding method outside the requirements of the present invention (Comparative Examples Nos. 5 to 5)
8) shows that any of the characteristics is inferior.

[Embodiment 2] This embodiment relates to claim 2. As shown in Table 3, an Al alloy brazing material containing 7.5 wt% of Si and 10.0 wt% of Si alloy on one surface of the 3003 alloy core material (to be the outer surface of the tube) was used at a cladding ratio of 1.5% to 7%. Cladding is performed, and a sacrificial anode material made of an Al-4 wt% Zn alloy is clad on the other surface (inside the tube) (cladding ratio: 10%), and combined with each other. .3m
m brazing sheet (three-layer material) was manufactured. Refining is H14.

[0030]

[Table 3]

The specific manufacture of the brazing sheet and the radiator tube is the same as in the first embodiment. In addition, an extruded flat multi-hole tube of a condenser tube (material 105
0), the same brazing sheet fins as in Example 1 were prepared by corrugating.

The radiator tube 11, the condenser tube 21 and the corrugated fin 31 are assembled as shown in FIG. 2 (one radiator tube 11 and one condenser tube 21 are placed one above the other, and the corrugated fin 31 is arranged between them). A test core was assembled so that the radiator core and the capacitor core were integrated.

Next, 10 g / m ² of a non-corrosive flux (mixed flux of KAlF ₄ and K ₂ AlF ₅ ) was applied to the test assembly core, and the coating was performed in a nitrogen gas atmosphere.
A test product was obtained by performing brazing and heating at 05 ° C. for 3 minutes.
The soundness of this test product was evaluated by observing the brazed state and the joined state of the R portion of the fin material (31R portion in FIG. 4). Table 4 shows the evaluation results.

[0034]

[Table 4]

As is clear from Table 4, the bonding method satisfying the requirements of the present invention (Examples Nos. 9 to 12) has a high soundness ratio of the fin R portion of the radiator core portion, and the fin of the radiator core portion. It can be seen that the bonding ratio of the is also high. There is no problem in joining the fins of the capacitor core. On the other hand, a bonding method outside the requirements of the present invention (Comparative Example No. 1)
3 to 16) indicate that one of the characteristics is inferior.

[0036]

As described above in detail, the present invention prevents the erosion of the R portion of the fin due to the brazing when manufacturing an integrated heat exchanger in which the radiator core and the capacitor core are integrally formed. Thus, a sound and high-performance integrated heat exchanger can be stably manufactured, and this has a remarkable industrial effect.

[Brief description of the drawings]

FIG. 1 is an example of an integrated heat exchanger according to the present invention,
It is the perspective view which cut out some radiator cores and a part of capacitor cores, and a part of header of a radiator core.

FIG. 2 is an enlarged perspective view showing a joined state of the condenser tube 21, the radiator tube 11, and the fin 31 of FIG.

3 is an enlarged cross-sectional perspective view showing a joint state between the radiator tube 11 and the fin 31 in FIG. 2;

FIG. 4 is an enlarged cross-sectional view showing a joint state between the radiator tube 11 and the fin 31 in FIG.

FIG. 5 is a cross-sectional view showing a material configuration of a radiator tube 11 according to the present invention, wherein (a) is an Al alloy core material 11;
In FIG. 3A, a brazing material 11b is clad on the outer surface, a sacrificial anode material 11c is clad on the inner surface, and (b) a brazing material 11b is clad on the outer surface of the Al alloy core material 11a.

FIG. 6 is an explanatory view showing an example of a conventional connection between a condenser tube 2a ^, a radiator tube 1a ^, and a fin 30 of an integrated heat exchanger.

FIG. 7 is a perspective view showing an example of a conventional so-called integrated heat exchanger in which a radiator core and a condenser core are integrally formed.

FIG. 8 is a perspective view showing an example of a conventional heat exchanger with a single radiator core.

FIG. 9 is a perspective view showing an example of a conventional heat exchanger with a single capacitor core.

[Description of Signs] 1 radiator core 1a, 1a ^, radiator tube 1b radiator fin 2 capacitor core 2a, 2a ^, capacitor tube 2b capacitor fin 2c ^, inner fin 30 fin of integrated heat exchanger 40 insert of integrated heat exchanger 5 , 6 Radiator header 6, 8 Capacitor header 10 Radiator core of integrated heat exchanger according to the present invention 11 Radiator tube 11a Al alloy core material of radiator tube 11b Brazing material of radiator tube 11c Sacrificial anode material of radiator tube 11d tube Fillet portion between fin and fin 12, 13 Header of radiator 14, 15 Water inlet / outlet of radiator 20 Condenser core of integrated heat exchanger according to the present invention 21 Condenser tubes 22, 23 Condensate Header 30,30 fin of integrated heat exchanger 31R R of fin 40,41 insert of integrated heat exchanger

Continued on the front page (72) Inventor Akio Niikura 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (72) Inventor Taketoshi Toyama 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture DENSO Corporation (72) Inventor Akira Uchikawa 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture, Denso Corporation (72) Inventor Satoshi Nohira, 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation (72) Inventor ▲ Taka ▼ Tatsuhiko 1-1-1 Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (2)

[Claims] 1. A radiator tube (11) and a condenser tube (2) in an integrated heat exchanger in which a radiator core ( 10 ) and a condenser core ( 20 ) are integrated.
1) A method of joining a fin (31) straddling both tubes, wherein the radiator tube (11) has an outer surface of an Al alloy core material containing Al containing 2 to 6.5 wt% of Si.
-A brazing tube material clad with a Si brazing material, and the condenser tube (21) is made of an Al or Al alloy extruded flat multi-hole tube, and furthermore, a fin (31)
Is 7 to 11 wt% of Si on both surfaces of Al or Al alloy core material.
The radiator tube (11), the condenser tube (21) and the fin (3) are formed of a brazing sheet fin material clad with an Al-Si brazing material containing
1) a method of joining tubes and fins of an integrated heat exchanger, wherein 2. A radiator tube (11) and a condenser tube (2) in an integrated heat exchanger in which a radiator core ( 10 ) and a condenser core ( 20 ) are integrated.
1) and a method of joining a fin (31) straddling the two tubes, wherein the radiator tube (11) has an outer surface of an Al alloy core material containing Al-containing 7 to 11 wt% of Si.
The capacitor tube (21) is made of an Al or Al alloy extruded flat multi-hole tube made of a brazing tube material clad with a Si-based brazing material at a cladding ratio of 2 to 5%,
Further, fins (31) are provided on both sides of the Al or Al alloy core material.
It is made of a brazing sheet fin material clad with an Al-Si brazing material containing up to 11 wt% of Si, and the radiator tube (11) and the condenser tube (21) are integrally brazed to the fin (31). A method for joining tubes and fins of an integrated heat exchanger.