JPH0790531A - Heat exchanger - Google Patents

Abstract

PURPOSE:To obtain a product prevented from the damage of corrugate fins and excellent in brazing property at high yield by specifying the flowability of a brazing filler metal for brazing side supports to the fines, in an aluminum base metal-made heat exchanger. CONSTITUTION:This heat exchanger is provided with tubes for a working fluid passage, the side supports arranged at the outside of the tubes and the fins placed between the tubes and between the tube and the side support and is produced by brazing the tubes and the side supports to the fins. The flowability of the brazing filler metal used for brazing the side supports to the fins is controlled to be lower than that of the brazing filler metal used for brazing the tubes to the fins. As a result, the high performance heat exchanger excellent in brazing property of the tubes to the fins and of the side supports to te fins is produced at high yield.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger made of aluminum or aluminum alloy (hereinafter simply referred to as aluminum alloy) for automobiles.

[0002]

BACKGROUND OF THE INVENTION For example, a heat exchanger such as a radiator, a heater core, an intercooler, and an oil cooler is shown in FIG.
It has a structure as shown in FIG. In FIG. 1, 1 is a side support, 2 is a tube (flat electric welded pipe), 3 is a corrugated fin, and 4 is a tank. The side support 1 is configured by using a brazing sheet having an Al—Si brazing material clad on one surface thereof, and the tube 2
Also, a brazing sheet having an Al—Si brazing material clad on one side and having a shape as shown in FIG. 2 is used, and after assembling as shown in FIG. 1, flux is used. The side support 1 and the corrugated fins 3 are brazed by brazing with the brazing material provided on one surface of the side support 1, and
The tube 2 and the corrugated fin 3 are brazed with a brazing material provided on the outer surface of the tube 2, and the side support 1 and the corrugated fin 3 and the tube 2 and the corrugated fin 3 are joined at their respective joints (brazing). is doing.

However, in the heat exchanger constructed as described above, the corrugated fins 3 may be damaged.

[0004]

DISCLOSURE OF THE INVENTION As a result of intensive research on the above problems, it has become clear that the damage to the corrugated fins 3 is due to the brazing material. That is, as a result of the brazing filler metal clad in the side support 1 and the tube 2 being heated to the brazing temperature and melting, the melted brazing filler metal drips downward due to the action of gravity, and the amount of the dripping accumulated increases. When it came, it became clear that the fins made of aluminum alloy were melted by a large amount of molten brazing filler metal. In particular, for example, the thickness of the brazing material clad in the side support 1 is 80 to 200 μm,
The brazing material clad in the tube 2 has a thickness of 20 to
Since the brazing material clad to the side support 1 is larger than the brazing material clad to the tube 2 such as 40 μm, the amount of the brazing material hanging down on the side of the side support 1 is large and brazed to the side support 1. It has also been found that the corrugated fin 3 that is being worn is greatly damaged.

The present invention has been achieved on the basis of such findings, and the object of the present invention is to braze the tube and the fin for the working fluid passage, and to arrange the tube outside the tube. It is an object to provide a high-performance heat exchanger having excellent brazing characteristics between side supports and fins with high manufacturing yield. An object of the present invention is to provide a tube for a working fluid passage, a side support arranged outside the tube, and fins arranged between the tubes and between the tube and the side support. A heat exchanger formed by flux brazing a tube, a side support and a fin, wherein the fluidity of a brazing material used for brazing the side support and the fin is a brazing material used for brazing the tube and the fin. Is achieved by using a brazing material having a fluidity lower than that of the heat exchanger.

The tube and side support are made of Al-
It is preferable that the brazing material is made of a brazing sheet in which a Si-based brazing material is clad, and that the Si content of the brazing material in the tube is higher than the Si content of the brazing material in the side support. For example,
The brazing material in the tube has a Si content of 8.5 to 11.
It is preferable to use an aluminum alloy of 0 wt% and the balance of Al and unavoidable impurities, and a brazing material in the side support having an Si content of 6.5 to 8.5 wt% and the balance of aluminum alloy of Al and unavoidable impurities. .

In particular, the brazing filler metal in the tube has an Si content of 8.5 to 11.0 wt% and the balance being aluminum alloy of Al and unavoidable impurities. The brazing filler metal in the side support has a Si content of 6.5 to 8%. 5wt%, the rest is A
It is an aluminum alloy of 1 and unavoidable impurities and has the following formula: 0.1 × t ₀ / t ₁ ≦ C ₁ −C ₀ ≦ 1.2 × t ₀ / t ₁ [where the thickness of the brazing filler metal in the tube is ₁ , the content of Si is C ₁ %, the thickness of the brazing filler metal in the side support is t ₀ , and the content of Si is C ₀ %]. Here, t ₀ is about 80 to 20.
0 μm, side support thickness is about 1.0 to 2.0 m
In general, m and t ₁ are about 20 to 40 μm, and the thickness of the tube is about 0.2 to 0.5 mm.

Further, the brazing filler metal used in the above is 0.2 w
t% or less Bi, 0.005 wt% or less Be, 0.7
One or two or more Fe of less than wt% may be contained. Further, other components may be contained to the extent that the function of the brazing material is not impaired. or,
In the present invention, flux brazing is adopted, and examples of the flux include NaCl and K.
Cl, LiCl, ZnCl _{2 and} other chlorides, KF, AlF
Any flux may be used as long as it is a flux used for ordinary flux brazing, such as a fluoride such as ₃ , LiF, KAlF ₄ , K ₃ AlF ₆ , ZnF ₂ or a mixture thereof. The flux is supplied by dissolving the above compound in a solvent such as water, alcohols such as methanol, ethanol, propanol and butanol, aldehydes, nitriles, esters, lactones and ethers and spraying it. Appropriate means such as coating may be used.

The present invention will be described below with reference to specific examples.

[0010]

EXAMPLE A brazing sheet composed of an Al-Si brazing material composed of alloy components shown in Table 1 below clad on one side of a 3003 alloy was used to form a 1.5 mm sheet.
Using a side support having a thickness (the thickness of the brazing material is 80 to 200 μm) and a brazing sheet in which an Al-Si brazing material composed of alloy components shown in Table 2 below is clad on one side of the 3003 alloy is used. 0.4mm configured
A tube having a thickness (the thickness of the brazing material is 20 to 40 μm) was prepared.

Table-1 No Side support brazing material composition (wt%) Brazing material thickness (μm) Si Bi Be Fe Fe Al 16.5 − − 0.25 Remaining 140 2 6.5 0.11 0.002 0.20 Remaining 130 3 7.0 − − 0.15 Remaining 150 4 7.0 0.01 0.0001 0.20 Remaining 160 5 7.5 − − 0.20 Remaining 60 6 7.5 0.12 0.0001 0.65 Remaining 180 7 8.0 − − 0.30 Remaining 130 8 8.0 0.01 0.0001 0.35 Remaining 120 9 8.5 − − 0.25 Remaining 80 10 8.5 0.01 0.0001 0.20 Remaining 190 11 11 5.5 − − 0.25 Remaining 130 12 9.5 0.01 0.0001 0.20 Remaining 140 Table-2 No brazing material composition of tube (wt%) Brazing material thickness (μm) Si Bi Bi Fe Fe Al 1 8.5 − − 0.30 Remaining 30 2 8.5 0.14 0.0001 0.25 Remaining 30 3 9.0 − − 0.35 Remaining 30 4 9.0 0.01 0.004 0.30 Remaining 30 5 9.5 − − 0.20 Remaining 20 6 9.5 0.01 0.0001 0.20 Remaining 40 7 10.0 − − 0. 15 Remaining 30 8 10.0 0.01 0.0001 0.65 Remaining 30 9 10.5 − − 0.25 Remaining 30 10 10.5 0.01 0.0001 0.20 Remaining 30 11 11.0 0.01 0.0001 0.20 Remaining 20 12 11.0 0.01 0.0001 0.20 Remaining 40 13 5.0 − − 0.25 Remaining 30 14 8.0 − − 0.20 Remaining 30 And side support of No1 to No12 above, No
1 to No. 14 tubes and corrugated fins are shown in FIG.
After assembling as described above, and then supplying flux to the side support and the corrugated fin, and the tube and the corrugated fin respectively by flux brazing (600 to 610 ° C. for a good joining of the tube and the fin, time 5 minutes). Was joined (brazed) at the joint part of.

With respect to the heat exchanger thus obtained, the brazing property at each joint and the degree of damage to the corrugated fins were examined. The results are shown in Table 3. Table-3 Side support tube C ₁ -C ₀ t ₀ / t ₁ Brazing support part Damage condition Port No No Temperature ℃ Brazing property Example 1 6 5 2.0 9.0 9.0 600 Good None Example 2 5 6 2. 0 2.1 600 Good None Example 3 3 3 2.0 5.0 5.0 600 Good None None Example 4 7 11 3.0 6.5 6.5 600 Good None None Example 5 1 3 2.5 2.5 4.6 600 Good None None Implementation Example 6 2 2 2.0 4.3 600 Good None None Example 7 2 4 2.5 4.3 600 Good None None Example 8 4 10 3.5 5.3 600 600 None None Example 9 8 10 2.5 4 0.0 600 Good None Example 10 1 11 4.5 7.0 600 Good None None Example 11 9 3 0.5 2.6 600 600 Good None Example 12 8 3 1.0 4.0 4.0 600 Good None Example 13 1 1 2.0 4.7 600 Good None Example 1 4 7 7 2.0 4.3 600 Good None Example 15 10 9 2.0 6.3 6.3 600 Good None Example 16 10 12 3.5 4.8 600 Good None Comparative Example 1 12 1 -1.0 4 0.7 600 Insufficiently bad Comparative example 2 12 3 −0.5 4.7 600 Insufficiently bad Comparative example 3 12 5 0 7.0 600 Good Very bad Comparative example 4 11 13 −0.5 4 3 610 Insufficiency None Comparative Example 5 3 13 −2.0 5.0 610 Good Poor Comparative Example 6 8 14 0 4.0 610 Good Very bad According to this, the heat exchanger according to the present invention has a side support. It can be seen that the brazing property is excellent at the joint portion between the corrugated fin and the corrugated fin, and the joint portion between the tube and the corrugated fin, and there is no defective product such as melting of the corrugated fin.

[0013]

[Effect] A high-performance heat exchanger having excellent brazing properties between the working fluid passage tube and the fins and the side supports and the fins can be obtained with a good manufacturing yield.

[Brief description of drawings]

FIG. 1 is a schematic view of a heat exchanger.

FIG. 2 is a sectional view of a tube.

Claims (5)

[Claims] 1. A tube for a working fluid passage, a side support arranged outside the tube, and fins arranged between the tubes and between the tube and the side support. A heat exchanger in which a side support and a fin are brazed by flux, and the fluidity of a brazing material used for brazing the side support and the fin is a fluidity of a brazing material used for brazing the tube and the fin. A heat exchanger characterized by using a brazing filler metal having a lower resistance than that of a heat exchanger. 2. The tube and the side support are made of Al-S.
The brazing sheet is formed by clad with an i-based brazing material, and the Si content of the brazing material in the tube is higher than the Si content of the brazing material in the side support. Heat exchanger. 3. The brazing material in the tube is an aluminum alloy having a Si content of 8.5 to 11.0 wt%, and the brazing material in the side support has a Si content of 6.5 to 5.
The heat exchanger according to claim 1 or 2, which is an aluminum alloy of 8.5 wt%. 4. The brazing material in the tube is an aluminum alloy having a Si content of 8.5 to 11.0 wt%, and the brazing material in the side support has a Si content of 6.5 to 5.
It is an aluminum alloy of 8.5 wt% and has the following formula: 0.1 × t ₀ / t ₁ ≦ C ₁ −C ₀ ≦ 1.2 × t ₀ / t ₁ [where the thickness of the brazing filler metal in the tube is t ₁ , the Si content is C ₁ %, the thickness of the brazing filler metal in the side support is t ₀ , and the Si content is C ₀ %]. Heat exchanger. 5. A brazing material having a Bi content of 0.2 wt.
The heat exchanger according to any one of claims 2 to 4, which contains Be of 005 wt% or less and Fe of 0.7 wt% or less in one kind or in two kinds or more.