JPS5993194A - Heat exchanger - Google Patents

Abstract

PURPOSE:To increase the strength of the heat exchanger and to improve the anticorrosive and sealing properties thereof by a method wherein a pure aluminum type alloy is clad on the entire surface of the cooling water side of a core plate and an Al-Si-Mg type brazing material is clad on the atmospheric side of the core plate. CONSTITUTION:A more than 99.5% pure aluminum alloy layer 11 of a thickness of 100mum is clad on a core material as the core plate 5 having the composition shown in the table (not shown) and a layer 12 of the brazing material is clad on the atmospheric side of the core plate. Then the core plate 5, a water pipe 1 and fins 2 are assembled together and brazed integrally by using a vacuum brazing method to thereby form a radiator core A.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heat exchanger in which a resin tank and a core plate are caulked and fixed via a sealing member, and is effective when used as a radiator for an automobile, for example.

In this type of aluminum heat exchanger, the core plate is required to be made of an aluminum alloy having a strength of 1 wA, corrosion resistance, and sealing properties.

Therefore, the present inventors firstly, as core play 1/material,
We tried using AIV, Mn-based alloys that have good corrosion resistance. However, in this material, Mn is added to improve strength.
It was found that when the amount of the material increases, the moldability becomes poor and cracks or cracks occur, making it unsuitable as a core plate material. Therefore, we next devised the application of Al1-Mg series and Δβ-Mg-3i series alloys, which are high-strength aluminum alloys, but Mg, which is an additive component to improve strength,
It was found that pitting corrosion occurs due to the influence of Si, leading to early water leakage. In addition, in order to apply the sacrificial corrosion prevention method, which is conventionally known as a pitting corrosion prevention method, we devised a method of forming a low potential layer of 80 to 120μ on the entire surface of the core plate on the cooling water side. It has been found that the low potential layer corrodes quickly, creating gaps in areas where sealing should be maintained, resulting in water leakage in a short period of time.

Conventional materials such as J2Jl have both advantages and disadvantages, and no material has been found that can satisfy the requirements for product crystallization ICs.

The present invention has been devised in view of two points, and is a core play of an aluminum heat exchanger with a resin tank.
・High strength and corrosion resistance are required characteristics.

Seal 1! The purpose is to make the J direction] 2.

Therefore, in the present invention, Δ
The cladding is made of pure aluminum alloy, which corrodes the slowest among the ρ alloys, to ensure long-term sealing performance. Moreover, in order for this cladding material to work as a 4ti 4ti anti-corrosion key, the high-strength core material contains Cu, a component that makes the potential noble.
is added to prevent pitting corrosion of the core material. That is, Mg:0.
4-3.0%, Cu:o, 2-0.8%, Si:
0.3-0.7%, Cr: 0.1-0.3%, balance A7
! The entire cooling water side is clad with an alloy with an A/line purity of 99.5% or more, and a ρ-31-Mg brazing filler metal is used on the atmosphere side. The structure uses either cladding or no cladding.

Here, Cr was added to the core material to suppress stress corrosion cracking susceptibility.

Next, one embodiment of the present invention will be described based on the drawings.

Figure 1 shows an automobile radiator, where ■ is a meter tube made of aluminum alloy (A3003 or A3 (+04)), and 2 is a corrugated fin, which is attached to the surface of aluminum alloy (A3003). It is clad with brazing filler metal (A4004). 5 is a core plate arranged at both ends 1a of the water tube (2), which is also made of aluminum alloy. These members (meter duplex 1. fin 2. core plate 1. 5)
are soldered together in a furnace to form the radiator core.

Reference numeral 3 designates an upper tank, which is made of, for example, a molded product of nylon resin containing glass fiber as a reinforcing agent, and is integrally molded with a second vibrator 10 that introduces cooling water from the engine. 6 is the lower tank also made of resin, and the output L1 pipe 7 sends the cooling water heat exchanged in the 21A part Δ to the engine.
, and is integrally molded with the drain vibe 8.

The upper and lower tanks 3.6 are connected to the core by tightening as shown in FIG. 2. That is,
Between the end 5a of the core plate 5 and the shoulder 3a of the tank 3 (6), along the end 5a of the core plate 5,
A sealing member 13 having a rectangular overall shape and a circular cross-sectional shape.
(for example, made of nitrile rubber), and in this interposed state, the core play 1 and the end portion 5a are caulked to the shoulder portion 3a, thereby fixing the core play 1 in a watertight manner.

Next, the material of the core plate 5 will be explained in detail.

(2) The core plate 5 of the first embodiment has a core material having the composition shown in Table 1.9! 10 (1
It is clad with a thickness of tr, and there is a wax shrine on the atmosphere side.
-1-3i- type) layer 12 is used.

And this core plate 5 and Umeter duplex l
Then, the fins 2 are assembled and integrally brazed by vacuum brazing to form the radiator core 8. As a means of vacuum brazing, each part is held in the radiator core with an assembly jig, and in that state, it is placed in a vacuum furnace at a temperature of 610°C and a vacuum degree of 5X] 0-5 atm and heated for 10 minutes. do. Thereafter, the radiator core 8 thus produced was attached to the resin tanks 3, 6 and the seal member 13 as described above.
By integrally caulking the end portion 5a of the core plate 5 through the radiator, the radiator with a resin tank is completed.

In the case of this example, alloys Nos. 8 to 13 in Table 1 had low melting points and could not be brazed, so they were not applied to this example.

2. Second Embodiment The core 8 of this embodiment was assembled by mechanical joining methods such as tube expansion and caulking without using vacuum brazing, and a resin tank 3.6 was assembled.
This is applied to the core bra of a solderless aluminum radiator, which is caulked and fixed via the sealing material 13 to complete the radiator.In this case, since it is a non-vacuum brazing method, it is used as the core material of the core play 1. For this, alloys 8 to 13 in Table 1 are applied, and No. 1 is applied to the entire surface on the cooling water side.
As in the case of the embodiment, a 99.5% or more pure aluminum alloy layer 11 is clad with a thickness of 100 μm, and the atmosphere side is not clad with a brazing filler metal.

This first. When the radiator formed by the manufacturing method of the second embodiment was subjected to monovalent testing using the method shown in Table 2, the results shown in Table 3 were obtained. As is clear from this evaluation result, C
If Cu is less than 0.2%, a sufficient potential for sacrificial corrosion protection cannot be obtained.On the other hand, even if Cu is added in an amount of 0.8% or more, the potential does not change, and the corrosion resistance of the core becomes inferior. Masoko, Mg, Si is Mg1
．． 4%, Si: 0. If it is less than 3%, the strength is insufficient; conversely, if Mg: 30% and Si: 0.
If it is 9% or more, stress corrosion cracking susceptibility cannot be suppressed by Cr, and the corrosion resistance of Cr itself deteriorates. Further, if the cladding ratio of pure aluminum alloy is less than 50 μm, no sacrificial corrosion protection effect can be obtained, and conversely, if the cladding ratio is more than 120 μm, the core play 1/closing strength will be insufficient.

As shown in Table 3, the depth of pitting of the core plate in which the core material of the alloy of the present invention is clad with pure aluminum alloy is within the cladding layer, and the sealing performance is 1.5 kg/- in water. No leakage occurred even when tested under pressure, and it was found that there was no problem in practical use.

In the above-mentioned embodiments, a radiator for an automobile was explained, but the heat exchanger of the present invention is not limited to an radiator for an automobile. It goes without saying that C can be widely used since heat exchange is performed between the two.

As explained above, the heat exchanger of the present invention has a core play of 1
・Since CLI is added to the high strength aluminum alloy No. 5 and 50 to 60 μm of pure aluminum alloy is formed on the entire surface of the cooling water side, the sealing performance between the resin tanks 3 and 6 and the core plate 5 is always maintained. Table 1 shows that the core plate 5 can be maintained in good condition and the corrosion resistance of the core plate 5 can be greatly improved. Chemical composition table of heartwood 2. δ-average method for core plate material Table 3. It has the effects shown in the evaluation results.

[Brief explanation of drawings]

FIG. 1 is a front view showing an example of the heat exchanger of the present invention, and FIG. 2 is a cross-sectional perspective view showing the main parts of the heat exchanger shown in FIG. ■... Duplex, 3.6... Tank, 5... Core plate, 11... Pure aluminum alloy layer, 12... Brazing metal layer. Representative Patent Attorney Takashi Okabe

Claims (1)

[Claims] In a heat exchanger comprising a resin tank, a core plate fixed to the resin tank through a sealing member by caulking, and a duplex whose end portion is connected to the core plate 1, the core plate of the core plate is As Mg: 0
．． 4-3.0%, cu: 0, 2-0.8%, Si: 0.
Using an alloy consisting of 3 to 0.7%, Cr: 0.3% or less, and unavoidable impurities to the rest, an alloy with a purity of 99.5% or more is applied to the entire surface of the cooling water side. 12
011 Krattsu and A7 on the popular side! -31-M
A heat exchanger characterized by being clad with G-based brazing filler metal or not being clad.