JPH0623527A - Production of heat exchanger - Google Patents

Abstract

PURPOSE:To suppress the residues generated at the time of implanting many pins by brazing to an aluminum plate to a lower level. CONSTITUTION:The aluminum plate 6 is formed with a brazing filler metal layer 9 on the surface of a core material 7. Polybutene 10 dispersed with a flux is applied on the surface of this brazing filler metal layer 9 and many pins 2, 2 are electrostatically attracted in this state thereto. The polybutene 10 is sublimated by heating arising from brazing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The method for manufacturing a heat exchanger according to the present invention relates to an improvement in the method for manufacturing a heat exchanger used as, for example, a heater core, an evaporator or a condenser.

[0002]

2. Description of the Related Art Flat heat transfer tubes, plate fins, etc.
For example, the outer diameter is 0.1 to 0.3 m on the surface of an aluminum plate (a plate made of aluminum or an aluminum alloy, which is the same throughout this specification) that constitutes the heat transfer surface of the heat exchanger.
A large number of fibrous pins with a length of m and a length of about 5 mm are planted, and heat exchange between fluids such as water flowing inside the heat transfer tubes and fluids flowing outside the heat transfer tubes is carried out through these many pins. What is being done is being studied. Further, a technique for arranging a large number of pins on the surface of a metal forming a heat transfer tube is described in, for example, Japanese Patent Application Laid-Open No. 2-290667.

FIG. 2 shows a state in which a large number of pins 2 and 2 are planted on the surface of a metal plate 1 by the technique described in this publication. A plating layer 4 of solder, solder or the like is formed on the lower surface of the metal plate 1 supported by the lower surface of the upper electrode 3a, and an adhesive flux layer 5 is applied to the lower surface of the plating layer 4. The pins 2 and 2 are connected to the lower electrode 3
The pins 2 and 2 are placed on the upper surface of b and electrically charged so that the pins 2 and 2 can be electrostatically attracted to the lower surface of the metal plate 1.

With such a structure, the large number of pins 2, 2 electrostatically attracted to the lower surface of the metal plate 1 are pierced by the flux layer 5 and temporarily held. Therefore, by heating the metal plate 1 in which a large number of pins 2 and 2 are pierced in the flux layer 5 on the lower surface in a heating furnace to melt the plating layer 4, the pins 2 and
The upper end of 2 and the lower surface of the metal plate 1 are joined by brazing or soldering.

[0005]

The method of manufacturing a heat exchanger of the present invention prevents generation of a large amount of residue at the joints between a large number of pins and an aluminum plate after brazing, and has a good performance. Is what you get.

In the case of the invention described in the above publication, the pin 2 is used.
In order to temporarily hold the flux on the lower surface of the metal plate 1, since the flux layer 5 is an inorganic or organic paste, the flux layer 5 remains as it is after brazing (in the case of an inorganic material), Alternatively, a large amount of residue produced by carbonization of the flux layer 5 may remain (in the case of an organic substance) to block the passage existing between a large number of pins 2 and 2,
It increases the ventilation resistance of the part and deteriorates the performance of the heat exchanger.

On the other hand, JP-A-1-143794-6 discloses a technique for brazing aluminum plates to each other by dispersing flux in polybutene that does not leave a residue by being sublimated by heating during brazing. Although described, the use of polybutene for the technique of implanting a large number of pins 2, 2 in an aluminum plate is not explicitly stated.

The method for manufacturing a heat exchanger of the present invention was invented in view of the above circumstances.

[0009]

According to the method of manufacturing a heat exchanger of the present invention, a large number of pins are mounted on the upper surface of a lower electrode whose upper surface is horizontal, and the lower surface of the upper electrode is the upper surface of the lower electrode. A brazing material layer is provided on the surface facing the horizontal surface, and an aluminum plate that constitutes the heat transfer member of the heat exchanger is abutted and supported with the brazing material layer as the lower surface, and flux is applied to the surface of this brazing material layer. With the dispersed polybutene applied, a voltage is applied between the lower electrode and the upper electrode to electrostatically adsorb the large number of pins to the lower surface of the aluminum plate,
After the end of each pin is adhered to the lower surface of the aluminum plate by the polybutene, the aluminum plate is removed from the lower surface of the upper electrode and heated in a heating furnace to melt the brazing material layer, And the step of brazing the end portion of the aluminum plate to the aluminum plate.

[0010]

According to the method of manufacturing a heat exchanger of the present invention having the above-described structure, the work of brazing a large number of pins on the surface of an aluminum plate can be easily performed, and a large amount of residue is left on the brazing part. It never happens.

That is, the polybutene used as the dispersion medium for the flux is in the form of honey and has a viscosity sufficient to hold the pins. Therefore, the polybutene is electrostatically adsorbed on the surface of the aluminum plate coated with the polybutene. The formed pins are temporarily held on the surface of the aluminum plate by the polybutene.

The large number of pins temporarily held on the surface of the aluminum plate as described above are based on the action of the brazing filler metal layer melted by the subsequent heating and the flux activated by the heating. It is brazed to the surface of the aluminum plate.

Polybutene, which is a copolymer mainly composed of isobutylene and has one double bond at the terminal, has a temperature (300 ° C.) lower than the brazing temperature (about 600 ° C.).
Sublimate at around ℃). Therefore, the presence of polybutene does not increase the residue after brazing.

[0014]

FIG. 1 shows an embodiment of the present invention. In this embodiment, a large number of pins 2 and 2 are planted on the surface of an aluminum plate 6 which constitutes a heat transfer tube through which cooling water flows. The aluminum plate 6 is JIS 3003
A JIS 7072 material anticorrosion coating 8 is formed on one surface (top surface in FIG. 1) of the material core material 7 in contact with the cooling water. The JIS 7072 material forming the anticorrosion coating 8 contains a relatively large amount of Zn and has a base potential (lower) than the JIS 3003 material forming the core material 7. The anticorrosion coating 8 prevents the core material 7 from being corroded by sacrificial corrosion when it comes into contact with the cooling water.

On the other hand, the other surface of the core material 7 (lower surface in FIG. 1)
Then, JIS 4343 material, which is an aluminum alloy containing a relatively large amount of Si and having a lower melting point than the JIS 3003 material and JIS 7072 material, is coated on the portion where the above-mentioned many pins 2 and 2 are to be implanted. To form the brazing material layer 9. Then, on the surface of the brazing material layer 9, the polybutene 1 in which the flux is dispersed
0 is applied. As the flux, as described in JP-A-1-143794-6,
Fluoride type flux is used.

The aluminum plate 6 as described above is the same as that shown in FIG.
The lower electrode 3a as shown in FIG. 2 is brought into contact with and supported by the lower surface of the upper electrode 3a with the brazing material layer 9 as the lower surface.
A voltage is applied between b and the upper electrode 3a. As a result, the large number of pins 2, 2 placed on the upper surface of the lower electrode 3b are electrostatically adsorbed on the lower surface of the aluminum plate 6. And these many pins 2 and 2 are adhere | attached on the lower surface of the said aluminum plate 6 with the honey-shaped polybutene 10.

In this way, when the large number of pins 2 and 2 are temporarily held on the surface of the aluminum plate 6, the aluminum plate 6 is removed from the lower surface of the upper electrode 3a and placed in a heating furnace (not shown). The brazing material layer 9 is heated to a temperature at which it melts.

The temperature of the aluminum plate 6 and the like placed in the heating furnace gradually rises.
When the temperature rises to about 0 ° C., the polybutene 10 applied to the surface of the brazing material layer 9 sublimes. When the temperature of each part further rises, then the flux is activated and then the brazing material layer 9 melts. As a result, the aluminum plate 6
A large number of pins 2, 2 temporarily held on the surface of the aluminum plate 6 are brazed to the surface of the aluminum plate 6. Since the polybutene completely sublimes before the brazing material layer 9 melts, a residue due to the presence of the polybuden 10 does not occur after brazing.

[0019]

Since the method for manufacturing a heat exchanger of the present invention is constructed and operates as described above, it is possible to prevent a large amount of residue from being generated in the brazing portion between the aluminum plate and the pin, and It is possible to suppress the increase in ventilation resistance and improve the performance of the heat exchanger.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view showing a conventional method.

[Explanation of symbols]

 1 Metal Plate 2 Pin 3a Upper Electrode 3b Lower Electrode 4 Plating Layer 5 Flux Layer 6 Aluminum Plate 7 Core Material 8 Corrosion Resistant Coating 9 Brazing Material Layer 10 Polybden

Claims (1)

[Claims] 1. A large number of pins are mounted on the upper surface of a lower electrode having a horizontal upper surface, and a brazing material layer is provided on the lower surface of the upper electrode on a horizontal surface facing the upper surface of the lower electrode. The aluminum plate that constitutes the heat transfer member of the exchanger,
Abutting and supporting the brazing material layer as the lower surface, applying a voltage between the lower electrode and the upper electrode in a state where polybutene in which flux is dispersed is applied to the surface of the brazing material layer,
After electrostatically adsorbing the large number of pins to the lower surface of the aluminum plate and bonding the ends of each pin to the lower surface of the aluminum plate with the polybutene, remove the aluminum plate from the lower surface of the upper electrode and heat. A method of manufacturing a heat exchanger, comprising the steps of heating in a furnace to melt the brazing material layer and brazing the ends of the pins and the aluminum plate.