JPH11172405A - Coating apparatus for aluminum alloy and coating method and coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively coat the surface of an aluminum alloy material with a uniform aluminum alloy. SOLUTION: This coating appratus for the aluminum alloy consists of a pressurizing device 17 which houses an aluminum alloy melt and pressurizes this melt while holding the melt at high temp., a molten metal heating section 20 which is disposed in the molten metal flow passage before and behind this pressurizing device at need, a spray nozzle 18 which uniformly disperses and sprays the molten metal subjected to pressurization and the aluminum alloy material 24 which is placed at a distance of 10 to 250 mm from the top end of the spraying nozzle 18 and is coated with an aluminum alloy brazing filler metal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for coating an aluminum alloy brazing material, and more particularly to an apparatus and a method for coating the outer surface of an aluminum alloy strip or tube for an aluminum heat exchanger member. Another object of the present invention is to provide a method and an inexpensive and high quality brazing material coating material.

[0002]

2. Description of the Related Art As an example of a heat exchanger made of aluminum alloy, a condenser is shown in FIG. Header pipe (3)
A multi-hole tube formed by extrusion is used as a tube (2) having both ends opened therein, and a brazing sheet fin clad with a brazing material is used as a fin (1). In recent years, to reduce the size and weight of heat exchangers, fins with limited thickness have been reduced to bare fins to reduce the thickness, and the outside of the tube is coated with brazing material by the following method, and these are combined and integrated by brazing. Have been proposed.

[0003] First, there is a method of using a molten metal as a brazing material supply source. For example, a method of plating a molten brazing material with a metal (Japanese Patent Application Laid-Open No. 60-255262) and a method of immersing it in a molten metal (Japanese Patent Application Laid-Open No. 63-255632). No. 299812), and a method of spraying a molten brazing material by blowing it off with a gas (Japanese Patent Application Laid-Open No. 4-75771) is known. The method of using the molten metal as the brazing material supply source can reduce the cost of the brazing material to be supplied, but has the following problems.

[0004] In the plating method using a molten metal, since a flux is used, oxides remaining on the plating surface cause irregularities on the surface, and defects occur during brazing. In addition, this method is a method in which a molten brazing filler metal is supplied by a jet or kept in a tank, and a pipe material is passed through the inside, but in the case of an aluminum alloy tube, the difference in melting point from the molten brazing material is small. Therefore, it is difficult to prevent the tube itself from melting, and this method is not particularly suitable for brazing a thin material.

In the method of immersing an aluminum alloy strip or aluminum alloy tube in a molten metal, it is difficult to control the speed and the like because the aluminum alloy strip or aluminum alloy tube is passed through a zinc bath immediately after extrusion, and therefore it is difficult to produce a uniform coating on the surface. Have difficulty. Further, there is a problem that the tube itself is eroded by the coating alloy.

[0006] In the method of spraying a molten brazing material by blowing it off with a gas, the use of gas requires gas supply system equipment and molten metal supply system equipment, so that the equipment becomes complicated and the cost increases. . Further, since the heated molten metal is cooled by the gas, there is much waste in energy efficiency. In addition, in order to eject the molten metal in a mist, the gas pressure must be equal to or higher than a predetermined pressure. At such a pressure, the molten brazing material fluctuates with the blowing gas, and the amount of the brazing material adhered becomes stable. There is no problem. Also,
The method of atomizing with gas is a kind of gas atomization, so it is suitable for spraying a large amount of molten brazing material.However, it coats the brazing material thinly and uniformly or coats the brazing material in a narrow area It was difficult.

As another method, there is a method of spraying a brazing alloy onto an extruded tube (JP-A-59-10467, etc.). However, this method is an industrial method in terms of brazing property, corrosion resistance and cost. It is not satisfactory in terms of quality, and the problem is particularly large in terms of cost. This is because the conventional thermal spraying method supplies a brazing material as a wire or powder, and the cost of manufacturing the wire or powder is very high.

In the case of this thermal spraying method, local unbonding is a problem of the brazing property and the corresponding corrosion resistance. The occurrence of a local unattached portion is a phenomenon peculiar to a tube sprayed with a brazing filler metal, and is indicated by reference numeral (5) in FIG. In this method, several stages of cores are prepared by combining a tube (2) sprayed with a brazing material and a corrugated fin (1), and brazing can be performed without any problem in the case of additional heating by brazing. It refers to a defective part where the tube (2) and the fin (1) which are generated in some places when brazing the heat exchanger are not brazed at all. When such a local unattached portion (5) occurs, the fin and the tube are not connected at this portion, so that not only the strength of the entire core is insufficient, but also the sacrificial corrosion prevention effect of the tube by the fin is exhibited. Otherwise, the corrosion resistance is extremely reduced. (4) in the figure is a side plate.

Therefore, the present inventors first examined the mechanism of the occurrence of a local unattached portion. As a result, the mechanism shown in FIG. 3 was found. FIGS. 3A and 3B are schematic diagrams showing the state of contact between the tube and the fin when the core is assembled before brazing. (B) shows a brazing material coated by a conventional method such as thermal spraying, and (A) shows a combination of a brazing sheet and fins. The distance L (apparent brazing material thickness) between the core material and the fin shown in the figure is, for example, about 100 μm when the brazing material is sprayed, and 20 μm or less for a brazing sheet clad with the same amount of the brazing material. It is. This is because when the brazing material is thermally sprayed, the brazing material has irregularities and cavities as shown in FIG. When brazing is performed in the state shown in FIGS. 3A and 3B, the tube (1) and the fin (2) come into direct contact with each other after brazing as shown in FIG. Distance L
Becomes zero. Therefore, in the case of a brazing filler metal spray tube,
The shrinkage of 200 μm (both sides at 100 μm) per tube occurs, and the shrinkage is accumulated for several to several tens of tubes, resulting in a strain of several mm, and the generation of a local unattached portion that is not brazed.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and as a result of extensive studies, it has been found that an apparatus for coating an aluminum alloy brazing material with another material, particularly a brazing material coating excellent in brazing properties, corrosion resistance and cost. A coating apparatus and a coating method capable of manufacturing aluminum alloy tubes and the like have been developed.

That is, the present invention provides a pressurizing apparatus for storing a molten aluminum alloy and pressurizing the same while keeping the temperature at a high temperature;
A melt heating unit provided in the melt flow passage before and after the pressurizing device as necessary, a spray nozzle for uniformly dispersing and spraying the pressurized melt, and a nozzle heating device provided as necessary And an aluminum alloy material coated with the aluminum alloy at a distance of 10 to 250 mm from the tip of the spray nozzle, and a coating device for the aluminum alloy. It is effective to use a molten metal and use an aluminum alloy strip or aluminum alloy tube for a heat exchanger member made of aluminum alloy as the aluminum alloy material.

At this time, it is effective that the aluminum alloy brazing material is an aluminum alloy brazing material consisting of Si: 7 to 40% by weight, Zn: 40% by weight or less, with the balance being aluminum. It is effective to apply 5 to 50 g / m ^{2 on} the surface of an aluminum alloy strip or aluminum alloy tube for an aluminum alloy heat exchanger. Furthermore, 4 to 500 g /
Injecting molten metal into the pressurizing device, installing a heat retaining device in the pressurizing device to maintain the temperature of the molten metal at 150 ° C. or more higher than the melting point of the brazing material, and removing impurities in the molten metal between the pressurizing device and the spray nozzle A booth capable of providing a filter or opening an inert gas injection port at the tip of the spray nozzle, covering the tip of the spray nozzle with inert gas, and replacing the spray area of the molten metal from the spray nozzle with inert gas. And the inside of the
It is also effective to be able to heat to 0 to 550 ° C.

The pressurizing device comprises a cylinder and a piston, and the piston pressurizes the molten metal at a pressure of 1 to 30 MPa, or directly pressurizes the molten metal with a pressurized gas at 0.1 to 10 MPa. The pressurizing device is good. In the latter case, it is preferable to provide a pressure storage tank between the pressurizing device and the pressurized gas supply source.

Further, the spray nozzle is preferably a spray nozzle having a flat type spray pattern. In particular, a groove having a V-shaped cross section or a U-shaped cross section having a depth of 0.1 to 3.0 mm is formed at the tip, and the bottom of the groove is formed. It is preferable that the through-hole has a minimum sectional area of 0.001 to 0.05 mm ² through which the molten metal pressurized. As the material of the tip, at least silicon carbide, tungsten carbide, carbon, alumina, magnesia, zirconia, silica,
Any one of calcia, yttria, boron nitride, silicon nitride, and aluminum nitride, or a mixture of two or more of these is preferred.

[0015] The method for coating an aluminum alloy brazing material according to the present invention is characterized in that the aluminum alloy brazing material is held at a temperature higher than the melting point of the aluminum alloy brazing material by 150 ° C. or more in a pressurizing device containing the molten metal. The molten aluminum alloy brazing metal in the molten metal flow passages before and after the pressurizing device is heated, and the molten metal is pressurized at a pressure of 0.1 to 30 MPa with the pressurizing device, and the molten aluminum alloy brazing material is melted from a spray nozzle. Is uniformly dispersed and sprayed at a rate of 4 to 500 g / min, thereby forming 5 to 5 g on the surface of the aluminum alloy strip or the aluminum alloy tube for the aluminum alloy heat exchanger member.
It is characterized in that an aluminum alloy brazing material of 0 g / m ² is adhered.

Further, the coating material of the present invention is characterized in that the molten aluminum alloy is held at a temperature of 150 ° C. or more higher than the melting point of the aluminum alloy brazing material in a pressing device containing the molten aluminum alloy brazing material. The molten aluminum alloy brazing material in the front and rear molten metal flow passages is heated, and
The molten metal is pressurized at a pressure of で 30 MPa, and the molten aluminum alloy brazing metal is uniformly dispersed and sprayed at a rate of 4 to 500 g / min from a spray nozzle, thereby spraying 5 to 50 g / m on the surface.
It was deposited ^second aluminum alloy brazing material is aluminum alloy heat exchanger member for aluminum alloy strip and aluminum alloy tube, characterized in.

Hereinafter, a method of coating an aluminum alloy brazing material using the coating apparatus of the present invention will be described in comparison with a thermal spraying method which has been conventionally proposed as a method of coating an aluminum alloy brazing material. Conventionally, when spraying a brazing material onto an aluminum alloy, an apparatus suitable for spraying an aluminum alloy brazing material among existing spraying apparatuses has been used. The features of such existing thermal spraying equipment are general-purpose types that are not limited to thermal spraying of aluminum alloys.
Small, compact and mobile. For this reason, in the case of the existing thermal spraying apparatus, the aluminum alloy brazing material is supplied as a wire or a powder, and is melted by an arc, gas, plasma or the like and sprayed onto the base material.

On the other hand, the present invention is an aluminum alloy coating apparatus characterized in that an aluminum alloy brazing material supplied as a molten metal is continuously sprayed under pressure, and is characterized in that the aluminum alloy brazing material is supplied as a molten metal. And continuously spraying the molten metal under pressure.

First, the feature of the present invention that the aluminum alloy brazing material is supplied as molten metal enables coating at a lower cost than the conventional thermal spraying method. That is, the conventional thermal spraying method supplies the brazing material as a wire or powder as described above, and the cost for manufacturing the wire or powder is extremely high. Further, since the workability of the brazing alloy is very poor, in the conventional thermal spraying method, when a brazing material is supplied as a wire, its components are limited, and a brazing alloy having improved corrosion resistance and brazing property cannot be used. On the other hand, in the present invention, an alloy having any composition can be coated because the molten metal is sprayed as it is. Furthermore, when thermal spraying is performed using a powder brazing material, there is a problem that the brazing property is reduced due to entrapment of the oxide film on the powder surface, but in the present invention, such a problem does not occur because the molten metal is sprayed as it is. .

Another feature of the present invention is that the molten metal is continuously sprayed under pressure. This is a major feature of the present invention. As a method of spraying the aluminum alloy melt, a method of blowing off a brazing material in a molten state by a gas, such as spray casting (a kind of gas atomizing method), can be considered.

However, such a method has the following problems, and its use is limited. First, since the brazing material is blown off by the gas flow, the gas pressure must be equal to or higher than a predetermined pressure in order to bring the molten metal into a spray state, but if such a pressure is used, the base material will move by gas injection. Material adhesion amount is not stable. There is also a problem that the cost of gas is increased. If the gas temperature is low, the molten metal will solidify at the moment it is blown off. Therefore, in order to prevent this, the temperature of the gas or the molten metal may be raised, but it is necessary to raise the temperature of a large amount of gas, which is difficult in equipment. On the other hand, the present invention is excellent in these points because the above-mentioned blowing gas is not used. Further, in the method of blowing off the molten brazing material by gas, the brazing material spreads unevenly unless a certain amount or more of the molten brazing material is supplied, so that it is necessary to supply an excessive amount of the brazing material. However, since there is a limit to the line speed of the base material during thermal spraying, there is also a problem that the amount of brazing material coated on the base material surface becomes too large.

In the conventional thermal spraying, it has been considered that the brazing material can be brazed without any problem if the thickness is, for example, about 40 μm. However, particularly when the amount of brazing material is increased, when a heat exchanger is manufactured by a brazing method using a tube coated with such brazing material, it is found that the above-mentioned local unattached portion becomes prominent. Issued and is a problem.

In order to prevent the occurrence of local unattached portions, it is theoretically possible to make the brazing material layer thin and reduce microscopic irregularities,
What is necessary is just to raise the filling density of a brazing material layer. In other words, the thinner the brazing material layer, the smaller the change in tube thickness before and after brazing, so that the occurrence of local unattached portions is less likely to occur. Reducing the thickness of the brazing material layer means reducing the amount of the brazing material, and it is necessary to reduce the brazing material to the point where brazing does not occur in order to prevent the occurrence of local unattached portions. According to the apparatus of the present invention, since the molten metal is continuously sprayed under pressure, a small amount of brazing filler metal can be supplied, and thus the mist-like molten metal particles of several tens of μm spread on the base metal. Therefore, coating with less microscopic irregularities is possible. On the other hand, in the prior art arc spraying, the brazing filler metal at the time of spraying has a diameter of several 100 μm and has large microscopic irregularities. In addition, the use of fine brazing filler metal powder by plasma spraying or gas spraying has the problem that the brazing filler metal particles are burned during thermal spraying and the production of fine powder is costly. Since it could not be used, the microscopic irregularities were still large.

In the coating using the apparatus of the present invention, the temperature of the brazing alloy at the time of spraying is 150 ° C. lower than the melting point of the alloy.
A higher temperature is desirable. By setting the temperature higher than 150 ° C., the flowability of the wax is improved, and the wax is dispersed flat and easily adheres to the surface of the base material. In this respect, in the case of the hot-dip plating conventionally proposed, the tube passes through the brazing material melt, so that the temperature of the brazing material needs to be close to the melting point in order to prevent the tube from melting. Although it is difficult, in the present invention, since only the temperature of the brazing material to be adhered needs to be considered, such a high temperature is desirable and the temperature control is easy.

The features of the brazing material coating method using the apparatus of the present invention have been described above. The apparatus of the present invention will be described in detail below.

First, FIG. 4 schematically shows the structure of an apparatus of the present invention of the type in which a molten aluminum alloy brazing material is pressurized by a piston. This apparatus melts an aluminum alloy brazing material (15) capable of melting a brazing alloy, and pressurizes the molten aluminum alloy brazing material supplied from the melting device to 1 MPa to 30 MPa by a hydraulic or hydraulic piston (16). A pressurizing device (17), a spray nozzle (18) for spraying the molten metal pressurized by the pressurizing device in a mist state, and an aluminum alloy strip or tube (24) continuously placed at a position of 10 mm to 250 mm from the tip of the nozzle. It is composed of a device to pass through.

Since the present invention is an apparatus for continuously spraying the aluminum alloy brazing material supplied as a molten metal by pressurization, a device (15) for melting the aluminum alloy brazing material is required. The melting device is usually capable of melting at least 4 kg of aluminum alloy brazing material. If it is less than 4 kg, the amount of the molten metal is too small and the heat capacity of the entire molten metal is insufficient, so that the temperature is not stable when supplying the molten metal to the pressurizing device.
When the temperature of the molten metal changes, the viscosity of the molten aluminum alloy changes, and the mist state changes, so that a stable amount of the brazing filler metal cannot be obtained. Therefore, the melting device is capable of melting the aluminum alloy brazing material of 4 kg or more, but a melting device capable of melting in the range of 10 kg to 100 kg is particularly recommended. The heating method for melting may be a general electric furnace, induction heating furnace, gas furnace, infrared image furnace, or the like, and is not particularly limited.

The present invention has a pressurizing device for pressurizing the molten aluminum alloy braze melted by the above-described device. After the molten brazing filler metal is transferred by the melting device, it can be pressurized in a closed state except for a connecting portion of a nozzle described later. The pressure can be set within a range of 1 MPa to 30 MPa. If the pressure is less than 1 MPa, the aluminum alloy brazing material does not form a mist when the molten brazing material is ejected from the nozzle, so that the brazing material does not uniformly adhere to the material.
The higher the pressure to press the molten metal, the more easily the molten metal disperses in a mist,
Although it adheres uniformly to the base metal surface, even if it exceeds 30 MPa, there is little change in the spouting state of the brazing filler metal, and conversely, there are many wastes such as measures to prevent the leakage of the molten metal from the device. It is sufficient if the pressure can be set up to 30 MPa. From the above, the device of the present invention is in the range of 1 MPa to 30 MPa,
The equipment can set the pressure for pressurizing the molten metal, but in consideration of the balance between the dispersibility of the molten metal and the equipment cost, it is especially 2 MPa.
It is recommended that the pressure can be set within the range of -10 MPa. Also, since the equipment cost increases as the pressure generated by the pressurizing device increases, it is necessary to obtain the amount of brazing material ejected per unit time, and the safety factor is multiplied by the pressure determined by the type of brazing alloy used. It is most recommended that the pressure applied be the maximum pressure for the device.

The pressurizing source (19) is hydraulic or hydraulic, and pressurizes the molten metal by a piston (16) connected thereto. Even if the molten aluminum alloy is ejected from the nozzle and the amount of the molten metal changes, measures are taken to keep the pressure applied, for example, to ensure a sufficient stroke length of the piston.

In the present invention, in particular, the molten metal pressurizing device (17)
It is recommended to provide a heat insulation device for the molten metal. When the brazing filler metal supplied from the melting unit to the pressurizing unit comes into contact with the surface inside the pressing unit, a part of it solidifies and melts again due to the heat of the molten metal. When the pressure reaches, the nozzle tip may be clogged at the start of pressurization. If the pressurizing device is previously heated to a temperature equal to or higher than the melting point of the aluminum alloy brazing material by the heat retaining device, the molten metal is not solidified when the molten metal is supplied to the pressurizing device. . Also, if the temperature of the molten metal changes during the spraying of the molten metal, the viscosity of the molten aluminum alloy changes, and the mist-like state changes, making it impossible to obtain a stable amount of brazing filler metal. And a stable amount of the brazing material deposited can be obtained. Such a heat insulator is provided with a heater (2
0) can be achieved. In this way, as a means for keeping the molten metal warm, it is also effective to install a device for heating the molten metal in the molten metal flow passages before and after the pressurizing device in addition to directly incorporating the thermal insulating device into the pressurizing device itself.

It is further recommended to provide a filter between the brazing material melting device and the spray nozzle for removing impurities in the molten brazing material. The reason is that when the brazing material is melted, oxides and the like may be entrained, which may clog the spray nozzle. As the filter, a filter generally used for filtering molten metal, such as a ceramic, is preferable.

A spray nozzle (18) for jetting the pressurized molten metal in the form of a mist is connected to a pressurizing device. Shall be sprayed. The spray nozzle may be designed so that the molten metal is dispersed and spread in the form of a mist on the surface of the base material to which the brazing material is sprayed, and a flat type nozzle having a spray pattern that spreads in a flat shape is particularly recommended.
The flat type spray pattern refers to a spray pattern for diffusing and spraying the molten metal in a flat shape, and as shown in FIG. 6, a planar spray pattern (44) formed on a surface (43) orthogonal to the spray direction. ) Are, for example, oval (44a), oval (44b), and strip (44)
c), spindle-shaped projection shape (44d) or convex lens shape (4
4e). At this time, the number of nozzles to be connected is not limited to one, and a plurality of nozzles may be provided as necessary.

It is recommended that the nozzle be provided with a nozzle heating device (21) as shown in FIG. The nozzle hole is likely to solidify the molten brazing filler metal, which often causes the molten metal not to be jetted out. Further, when the molten metal solidifies and adheres to the nozzle tip (22), the spray pattern changes, and stable brazing material cannot be coated. Such a problem,
The problem can be solved by heating the nozzle with a heating device (21) such as an electric heater.

Further, an inert gas (23) is provided around the nozzle.
It is recommended that the device be capable of flowing water. This is because the nozzle is exposed to high temperature and reacts with oxygen in the atmosphere to cause severe deterioration. In particular, before the molten metal is ejected, the effect is obtained by flowing when the nozzle is heated by heat from the molten metal or a heating device. Since it is not a gas for atomization, it is used as a small amount that does not flow during spraying or does not affect the spray pattern. The inert gas is a gas that does not react with the material of the nozzle, and a different gas may be selected depending on the material of the nozzle, but an argon gas or a nitrogen gas is generally used.

It is recommended that the nozzle be a nozzle that jets the molten metal at a rate of 4 g / min to 500 g / min when the molten metal is pressurized to the predetermined pressure. If it is less than 4 g / min, the ejection amount is small, the productivity is low, and the diameter of the nozzle for ejecting the melt at less than 4 g / min is too small to easily cause clogging of the melt. 5
If it exceeds 00 g / min, the amount of molten metal is too large, and it is necessary to increase the moving speed of the tube or strip to which the molten metal is adhered in order to attach a predetermined amount of brazing material. Does not adhere.

In the apparatus of the present invention, 1
At a position of 0 mm to 250 mm, a device for continuously passing an aluminum alloy strip or tube (24) covering the aluminum alloy brazing material is provided. This is because the brazing filler metal is continuously and uniformly coated by passing through the aluminum alloy strip or tube. If the distance is less than 10 mm from the tip of the nozzle, the molten metal does not spread sufficiently in the form of a mist, so that stable brazing material coating cannot be performed. On the other hand, if it exceeds 250 mm, the speed of the molten metal decreases and the brazing filler metal particles do not spread when adhering to the aluminum alloy strip or tube, and depending on the temperature of the molten metal or the atmosphere, before the brazing filler metal particles reach the strip or tube. Coagulates and does not adhere to strips or tubes. From the above,
The apparatus of the present invention is provided with a device for continuously passing an aluminum alloy strip or tube at a position of 10 mm to 250 mm.
A range of 50 mm is particularly recommended. When a plurality of nozzles are provided in order to secure a predetermined amount of adhesion, the strip or tube is passed through a position 10 mm to 250 mm from the tip of each nozzle.

The amount of the brazing material deposited by spraying is 5
g / m ² or more and 50 g / m ² or less is recommended.
It is recommended m ² or less. As described above in item [0023], this is because the smaller the brazing material, the smaller the microscopic unevenness and the effect of preventing the occurrence of a locally unattached portion. The lower limit is required to be 5 g / m ² or more as a minimum amount in order to prevent the occurrence of brazing.

An aluminum alloy such as an aluminum alloy brazing material is sprayed and adhered by using the coating apparatus of the present invention, and any aluminum alloy material can be used as a material coated with the aluminum alloy. As the target material when the molten aluminum alloy brazing material is used, an aluminum alloy strip or an aluminum alloy tube used as a member of an aluminum alloy heat exchanger is suitable. The aluminum alloy strip is a strip manufactured by rolling or extrusion, and the tube is a strip manufactured by extrusion or processed into a tube by processing a strip manufactured by rolling.
The extrusion here may be any of direct extrusion, indirect extrusion, and conform extrusion. The material of the strip or the tube may be an aluminum alloy that can be brazed, such as 3003 alloy or 1100 alloy, and has characteristics such as corrosion resistance required depending on the application. As a tube,
Most preferably, extruded multi-hole tubes and pipes used in tubes and pipes for aluminum alloy heat exchangers can be raised.

In the present invention, it is recommended that the booth (25) cover the periphery of the portion where the nozzle and the aluminum alloy strip or tube pass and the molten metal passes, and that the booth be heated to 200 ° C. to 550 ° C. It is also recommended that the booth be replaced with an inert gas. By heating the inside of the booth to 200 ° C. to 550 ° C., the molten metal solidifies at the nozzle tip and becomes hard to adhere, and the spray pattern is stabilized. Further, the ejected brazing filler metal particles are less likely to solidify before reaching the strips or tubes, and the brazing material is more likely to adhere to the strips or tubes and spread. It is also recommended that the booth be replaced with an inert gas. The inert gas atmosphere around the nozzle prevents deterioration of the nozzle. In addition, since it is possible to prevent the formation of an oxide film on the surface of the mist-like molten brazing material, the adhesion of the brazing material is improved, and the brazing property of the obtained brazing material can be improved. Further, explosion due to rapid oxidation of the atomized aluminum brazing material can be prevented.

Next, FIGS. 7 and 8 show a device of the present invention of the type in which the molten brazing material is directly pressurized by gas.
First, the aluminum alloy brazing material is put into a brazing material melting and pressing device and melted. Since the melting and pressurizing device (45) pressurizes the molten brazing material with gas, it must maintain airtightness. The brazing filler metal can be dissolved in the atmosphere,
Dissolution in an inert gas or reducing gas atmosphere is preferable because formation of oxides and the like can be suppressed. Further, the brazing material is melted in another melting furnace different from the brazing material melting and pressing device, and the molten brazing material is supplied to the brazing material melting and pressing device (45). It is also possible to use it.

In this apparatus, the molten brazing material is pressurized by gas. The device for pressurizing the brazing material with gas includes a pressure regulating valve (46), a high-pressure gas supply device (47), and the like. The high-pressure gas supply device (47) is preferably a gas cylinder, a compressor, or the like. As a gas for pressurizing the molten brazing material, an inert gas such as nitrogen or argon is preferable. The pressure regulating valve (46) is 9.8 MPa (100 kgf / cm
² ) The pressure can be adjusted with the following pressure. However, when the molten brazing material is pressurized at a pressure of less than 0.098 MPa (1 kgf / cm ² ), the aluminum alloy brazing material has a specific gravity and viscosity different from that of water and organic solvents and is difficult to spray. Does not spray. Therefore, it does not adhere uniformly to the pipe material or the like.

The greater the pressure for pressurizing the brazing material, the easier it is to spray the molten brazing material in the form of a mist, so that the brazing material adheres evenly to the surface of the tube. However, 9.8 MPa
Even if the molten brazing material is pressurized with a pressure exceeding (100 kgf / cm ² ), the molten brazing material does not change greatly in the spray state, and on the contrary, the pressure resistance and airtightness of the device must be improved, which increases costs. . Considering the cost of manufacturing pressure-resistant equipment and the sprayability of the molten brazing material, the particularly recommended brazing material pressurizing pressure is about 2 to 2.
It is 4.5 MPa (20-46 kgf / cm ² ).

In the present invention, the brazing material melting and pressing device (45)
And a high-pressure gas supply device (47).
8) is recommended. When the brazing material melting and pressurizing device vibrates for some reason and the liquid level fluctuates, the pressure fluctuates, and the brazing material spray amount may fluctuate. This is because a rapid change in pressure cannot be followed by pressurization with gas. Therefore, the accumulator tank (48)
The brazing material melting and pressurizing device (45) and the high pressure gas supply device (4)
7), it can be used as a buffer, and the pressure can follow even if the liquid level fluctuates rapidly.

The other structure of the above structure is the same as that of the cylinder pressurizing type device shown in FIG. FIG. 8 shows another example of the spray nozzle (18).

In any of the above types of apparatuses, it is effective to install a plurality of brazing material melting and pressurizing apparatuses. This will be described with reference to an apparatus of a type in which the molten brazing metal is pressurized by the above-mentioned gas. As shown in FIG. When the remaining amount becomes small, if one brazing material melting and pressing device (45) is used, the coating of the brazing material on the pipe material must be stopped and the brazing material must be melted again. However, when there are a plurality of brazing material melting and pressing devices, even if the supply of the brazing material from one brazing material melting and pressing device (45a) to the spray nozzle is stopped, the other brazing material melting and pressing device ( 45b)
And the brazing material can be continuously coated. When the spraying of the molten metal is finished, the supply of the brazing material from one brazing material melting / pressing device (45a) is stopped, and the other brazing material melting device (45) is stopped.
b) The inside is emptied, and when gas is sent to the spray nozzle through this, the spray nozzle (18), the brazing material introduction pipe (54)
Can be washed.

The apparatus of the present invention described above can be used for general aluminum alloy melts.
It is recommended to use an aluminum alloy brazing material consisting of 7 to 50% by weight, Zn: 40% by weight or less, with the balance being aluminum, as the molten metal. Si is an essential element for lowering the melting point of the alloy and making the alloy a brazing material. If the amount is less than 7% by weight, the melting point of the alloy does not sufficiently decrease, and is not suitable as a brazing filler metal. In the apparatus of the present invention, it is necessary to completely dissolve the alloy in order to spray the molten alloy. However, if it exceeds 50% by weight, the melting point becomes too high and the heat resistance of the apparatus is required, so that the cost of the apparatus increases. Too much.
From this point, it is recommended to use an apparatus using a brazing filler metal having a Si content of 7 to 13 wt%. It is particularly recommended that the brazing alloy contain 15 wt% or more and 35 wt% or less of Si. This is because if the amount of the brazing material to be coated is reduced by making the Si content larger than that of a normal brazing material alloy, no brazing occurs, which is advantageous in terms of manufacturing cost. Further, by reducing the amount of brazing material to be coated, there is an effect of preventing the occurrence of a locally unattached portion.

Zn other than Si may be added for the purpose of improving corrosion resistance as long as it does not affect the brazing property. There is no problem even if Zn is added up to 40%.
It is an element recommended to be added because it has the effect of lowering the melting point of the brazing alloy, making it easier to control the temperature of the molten metal with this device.

Elements other than Si and Zn, such as Fe, Cu, and Mn, may be added for the purpose of improving corrosion resistance and the like within a range that does not adversely affect brazing properties. As other unavoidable impurities, other elements (often added to brazing alloys for the purpose of improving corrosion resistance, improving brazing flowability, refining crystal grains after brazing, etc., may affect the effects of the present invention). ) May be contained as long as each is 0.30 wt% or less, but is preferably 0.05 wt% or less. Here, typical inevitable impurities include Mg, Cr, Zr, Ti,
Bi, Be, Li, In, Sn and the like can be mentioned.

In the present invention, various examinations have been made on the spray nozzle used in the above-mentioned apparatus, and a nozzle optimal for the purpose of the present invention has been developed. That is, when a conventional nozzle having a small-diameter hole is used as a spray nozzle, and when a brazing material is jetted from the hole, the molten brazing material becomes a DC rod shape, and it is extremely difficult to form a uniform brazing material film on the pipe material surface. It was difficult. Also,
Normal spray nozzles include those for water and organic solvents. These conventional nozzles are used for cleaning / painting by spraying a large amount of water or organic solvent, etc. The minimum cross-sectional area of ()) is usually about 0.06 mm ² . Also, since these nozzles are used at room temperature,
The material cannot withstand the temperature at which the aluminum alloy brazing material melts, making it difficult to use. In addition, since water and organic solvents and aluminum brazing materials have different basic properties such as viscosity and specific gravity, it is difficult to spray the brazing material with the same nozzle shape as the spray nozzle.

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, by using the following nozzle, the molten brazing material was sprayed by directly applying pressure to aluminum or aluminum alloy. It has been found that a brazing film can be uniformly formed on the surface of a tubular member made of PTFE.

Hereinafter, the spray nozzle of the present invention will be described in detail. If the brazing material is ejected by directly applying pressure to the molten brazing material using the nozzle of the present invention, the brazing material is sprayed in a mist state, and a uniform brazing film can be formed on the surface of the pipe material. In addition, since the brazing material coating method using the nozzle of the present invention does not use the processed wire or powder, the supplied brazing material does not cost much. In addition, since the molten metal is not sprayed in a mist state by blowing off the molten metal with a gas, there is no need to use a gas for spraying,
Further, there is an advantage that the device is simplified and the cost is not required. Another advantage is that the brazing material powder that has not adhered can be reused.

Normally, when a pressure is directly applied to a molten aluminum alloy brazing material and the brazing material is ejected from a small-diameter hole, the brazing material is ejected in a straight rod shape. It is difficult to form a uniform brazing film on a pipe with a brazing material ejected in a straight rod shape. If the hole diameter is increased to form a uniform film, the amount of the brazing material to be adhered increases, and conversely, a good brazing material film cannot be produced.

The present inventors set the tip of the molten metal jet port to a section U
It has been found that the molten metal can be sprayed uniformly by opening at the bottom of the V-shaped or V-shaped groove. At this time, if the groove depth is less than 0.1 mm, spraying cannot be performed.
If it exceeds 0 mm, the resistance of the liquid flow becomes large, the dispersion of the spray state becomes large, and good spray cannot be performed. The molten aluminum alloy brazing material differs in specific gravity, viscosity and the like from water and organic solvents. Therefore, rather than water or organic solvents, etc.
Since it is more difficult for the molten brazing material to spray the liquid, a nozzle having the above-described shape is required.

It is known that the brazing material film thickness of an aluminum alloy tube used for a heat exchanger or the like is preferably 5 to 50 μm in order to obtain good brazing properties. In order to form a brazing film of the above thickness,
If the minimum cross-sectional area of the molten metal passage portion through which the molten aluminum alloy brazing material passes is less than 0.001 mm ² , the amount of the brazing material ejected is small, and it is difficult to form a uniform coating. Further, when the area of the hole is less than 0.001 mm ² , clogging is likely to occur when the molten metal is ejected. On the other hand, if the area exceeds 0.05 mm ^2, on the other hand, the amount of the brazing material ejected is too large, so that it is difficult to form a uniform spray state, and the moving speed of the tube coated with the brazing material is increased. And the workability of the tube becomes difficult.

[0055] to allowed to form a wax coating for good brazeability of the thickness, the minimum cross-sectional area and most preferably the molten metal passage portion is 0.005 mm ² or more 0.015 mm ² or less. If it is less than 0.005 mm ² , the particle size becomes too fine when the brazing material is sprayed, and the adhesion to the tube material is inferior. On the other hand, if it exceeds 0.015 mm ² , the particle size will be increased conversely, so that the variation in the brazing material coating thickness of the pipe material will increase. Nozzles used for water and organic solvents are used for cleaning and painting, etc.
Usually, the minimum cross-sectional area of the hole is often larger than these. By defining the shape of the nozzle tip as described above, a spray nozzle having a more effective spray pattern can be obtained.

The shape of the hole from which the molten metal is ejected, that is, the shape of the opening at the bottom of the groove at the tip may be a perfect circle, an ellipse, or a rectangle, and is not particularly limited. It is also effective to form a spiral groove on the inner surface of the spray nozzle so that the molten metal is swirled when the molten brazing material passes through the inner surface of the spray nozzle.

The material at the tip of the nozzle through which the molten metal passes is
It must be difficult to react with the brazing filler metal. For example, an iron-based material such as stainless steel reacts with the molten brazing material, and there is a problem that the hole at the nozzle tip becomes larger each time it is used. Accordingly, the main material of the nozzle tip portion is made of aluminum carbide such as silicon carbide, tungsten carbide, carbide such as carbon, oxide such as alumina, yttria, and zirconia, and nitride such as boron nitride and silicon nitride. It is necessary to use a material that does not easily react with the material.
When the nozzle is used in the atmosphere, it is preferable that the material is an oxide since oxidation and deterioration of the nozzle due to oxygen easily occur.

The material of the brazing material for forming the brazing film is Al-Si, Al-Zn, Al-Si-Mg, Al
-Si-Zn, Al-Si-Cu, Al-Si-Cu-
It is required to have a melting point lower than that of the aluminum or aluminum alloy tube to be brazed and the fin material. Usually, the brazing temperature of these brazing materials differs depending on the alloy composition of the brazing material. The brazing temperature range covering the entire brazing material is 380-620.
° C. The brazing temperature of the brazing material used is 6
If the temperature is higher than 20 ° C., in the case of any brazing material, the aluminum alloy to be brazed (the material to be brazed) reacts with the brazing material to melt the aluminum alloy to be brazed, or is maintained at a high temperature by brazing heating. As a result, the strength is reduced, and it cannot be used as a heat exchanger. Further, the lower limit is set to 380 ° C. because Al—Zn 2 having the lowest melting temperature is used.
This is because the melting temperature of the brazing material is 380 ° C. or higher even in the original alloy brazing material, and if it is lower than this temperature, the brazing material does not melt and brazing cannot be performed.

However, industrially, not only brazing is possible but also productivity, yield and the like become problems. Taking these points into consideration, the brazing temperature is more preferably in the temperature range of 500 to 600 ° C. and preferably in the range of the melting point of each brazing material or more. If the brazing temperature is 500 ° C. or lower, the brazing material temperature is low, so that the adhesion to the brazing partner material is reduced and the brazing yield is reduced. Further, when the brazing temperature exceeds 600 ° C., there are problems such as erosion of the mating material due to diffusion dissolution reaction with the brazing material and reduction in strength of the brazing material due to brazing heating. If the temperature is lower than ℃, erosion due to diffusion melting and strength reduction due to brazing heating are sufficiently suppressed, and the required strength and corrosion resistance after brazing are further improved as compared with the case where the brazing temperature is 620 ° C. Therefore, the brazing temperature must be not lower than the melting temperature of each brazing material because the brazing material must be completely melted in the above temperature range of 500 to 600 ° C. Therefore, the most preferable brazing temperature range is 500 to 600 ° C., and the minimum temperature must be equal to or higher than the melting temperature of each brazing material. That is, the melting point of the brazing material used in the brazing material is 500
When the temperature is below ℃, the preferred brazing temperature range is 500 to
At 600 ° C., if the melting point of the brazing material used exceeds 500 ° C., the preferred brazing material temperature range is from the melting temperature of the brazing material to 600 ° C.

FIGS. 10, 11 and 12 are schematic sectional views showing one embodiment of the spray nozzle (18) of the present invention. The molten brazing material passes from the molten metal passage portion (61) to the molten metal passage portion (63) in the nozzle tip end portion (62) and is sprayed in a mist form from the molten metal diffusion portion (64). Here, the molten metal passage portion with the minimum cross-sectional area of the nozzle refers to a place in the nozzle where the cross-sectional area of the hole is smallest. Since the molten metal flows at a high speed at the nozzle tip, the material must be a material that does not easily react with the molten aluminum alloy as described above. In addition, it is preferable, but not particularly limited, that the entire nozzle is made of the above-described material, not just the tip of the nozzle.

[0061]

EXAMPLE 1 An apparatus of the type shown in FIG. 4 for pressing molten metal with a piston was manufactured, and a brazing material was coated under the set conditions of the apparatus shown in Table 1. The apparatus has a tilting crucible furnace (15) capable of melting 30 kg of aluminum alloy by heating with a heating wire as a brazing material melting device (15), and a refractory for supplying the molten aluminum alloy brazing metal melt to a pressurizing device. It has a gutter (29) made of material.

The pressurizing device (17) is a device for pressurizing the molten brazing alloy supplied through the gutter (29). The pressurizing device (17) is closed during pressurizing to supply the molten metal into the cylinder (30). Has an opening capable of being used. The capacity of the cylinder is about 16 liters, the inner diameter is about 20 cm, and the length is about 50
cm. One side of the cylinder has a piston (1
6) is provided, and the opposite side of the piston is closed except for a melt outlet (32) having a diameter of 10 mm, which feeds the aluminum alloy brazing filler metal to the nozzle. The cylinder and the piston are heat-resistant steel whose side in contact with the aluminum alloy melt is ceramic-coated, and an electric heater (20) capable of heating the melt up to about 800 ° C. is incorporated in the heat-resistant steel. In this embodiment, heating was performed at a temperature of + 150 ° C. of the melting point of the brazing material under all conditions. The piston stroke is about 50cm, the piston is connected to a hydraulic press with a maximum capacity of 1000t, and 1MPa
It is possible to apply any pressure of 〜30 MPa.

The opening on the opposite side of the piston of the pressurizing device is connected to a ceramic spray nozzle for jetting molten metal having a flat type spray pattern through a heat-resistant steel pipe having an inner diameter of 10 mm. The nozzle is detachable in a so-called cartridge system, and replacement is easy. The characteristics of these spray nozzles are shown in the nozzle column of Table 1. The opening angle in the table refers to the opening angle α at the time of spraying in FIG. Around the nozzle, the nozzle can be up to 700
A heating wire (21) capable of heating up to 600 ° C. was provided, and in this embodiment, the heating wire was heated to 600 ° C. in all cases. Further, argon gas was flowed around the nozzle until immediately before spraying the molten metal.

A grooved roller (40) as shown in FIG. 4 was installed so that the aluminum alloy strip or tube could pass between 10 mm and 250 mm from the nozzle tip. Roller position is variable, from nozzle to tube (strip)
The distance to (24) was changed under each condition as shown in Table 1 and carried out. An unwinder (41) for unwinding the aluminum alloy strip or tube supplied as a coil and a winder (42) for rewinding the coil again are installed before and after the roller, and the above position is continuously set at a maximum of 250 m / min. It was a device that could pass through.

Further, a booth (2 mm in height, 500 mm in width, 800 mm in length) was formed by a nozzle and a portion of the molten metal ejected from the nozzle on the aluminum alloy strip or tube.
5) (The pressurizing device, coil unwinder, winder, etc. were placed outside the booth).
The temperature inside the booth is changed by a heater that can be heated to 50 ° C. as shown in Table 1, and a nitrogen gas supply device is provided. The booth can be replaced with nitrogen gas (the opening through which aluminum alloy strips or tubes pass 60% or more can be replaced).

[0066]

[Table 1]

Using such an apparatus, the following two materials (tube and strip) were coated with an aluminum alloy brazing material. One is a multi-hole flat tube (1.8 mm height, 16 mm width,
This is a tube coil that has been cold blasted on both sides after being extruded into 19 holes. The other is 3003
One side of the alloy is a 10% Al-1% Zn alloy clad 10% clad, 0.30mm thick, 37mm wide strip coil not subjected to Al-1% Zn alloy clad cold strip blasting It is. On the blasted surface of these coils,
A brazing alloy (composition of a base metal and a master alloy) having the composition shown in Table 2 was used to form an alloy having a predetermined composition in the melting apparatus of the present apparatus. Fe was 0.8 wt% or less as an impurity and 0.15 wt% of other elements. %
Was coated under the conditions shown in Table 2. In addition, the brazing material was coated on both surfaces by passing the tube twice.

[0068]

[Table 2]

Regarding the brazing material-coated tube, the obtained porous tube was cut into a length of 580 mm, and a corrugated Al-0.5% Si-1% Fe-0.5 having a plate thickness of 0.07 mm was used.
The two heat exchanger cores shown in FIG. 1 were assembled in combination with a% Ni-1% Zn alloy fin and a 3003 alloy header pipe. A fluoride-based flux was applied to the assembled core and brazed under a heating condition of 595 ° C. × 3.5 minutes in a nitrogen atmosphere.

Table 3 shows the results of observing the appearance of the core after brazing and examining whether or not a locally unattached portion has occurred. Further, the first core was cut out of a tube of 20 fins from a portion where a local unattached portion did not occur, and the brazing state was evaluated by the fin adhesion rate. That is, the fins are peeled off from the tube, and the adhesion rate of the completely bonded one is set to 100%, and the unbonded part is (length of the bonded part) / (length of the bonded part) + Length of unbonded portion) was multiplied by 100 to obtain an adhesion rate (%). Table 3 shows the results. In addition, one core was subjected to a CASS test to examine corrosion resistance. Table 3 shows the test results.

The strip was cut into a width of 16 mm and a length of 200 mm, and a corrugated Al—
A single-stage core was assembled in combination with 0.5% Si-1% Fe-0.5% Ni-1% Zn alloy fins. A fluoride-based flux is applied to the obtained core (without applying flux for a resin containing a flux), and brazing is performed under a heating condition of 595 ° C. × 3.5 minutes in a nitrogen atmosphere. did. The brazing condition was evaluated based on the fin adhesion rate.
That is, the fins are peeled off from the tube, and the adhesion rate of the completely bonded one is set to 100%, and the unbonded part is (length of the bonded part) / (length of the bonded part) + Length of unbonded portion) was multiplied by 100 to obtain an adhesion rate (%). Table 3 shows the results.

[0072]

[Table 3]

As shown in Table 3, the tube manufactured by the apparatus of the present invention has no local unattached portion, has a high fin joining rate, has good corrosion resistance, and has a strip manufactured by the apparatus of the present invention. , Can be brazed.

(Example 2) A brazing material was coated under the conditions shown in Table 4 using an apparatus of the type shown in FIG. About 10 kg of an aluminum brazing material was supplied to the brazing material melting and heating device (45) in FIG. 7, melted in an inert atmosphere, and the temperature of the molten metal was kept at + 150 ° C. of the melting point of the brazing material. As the spray nozzle (18), a removable ceramic spray nozzle having a flat type spray pattern was used. A heating wire capable of heating to about 700 ° C. was wound around the nozzle, and the nozzle was heated to 600 ° C. A positionally variable grooved roller (40) is installed so that an aluminum alloy strip or tube can pass between 10 mm and 250 mm from the nozzle tip. In this example, the distance from the nozzle tip to the tube (strip) is 50 mm. did. Aluminum alloy strip and tube (2
An unwinder (41) for supplying 4) and a winder (42) for rewinding the coil are arranged before and after the roller, so that the apparatus can continuously pass the above position at a maximum of 250 mm / min. . Further, the nozzle and the portion of the molten metal ejected from the nozzle on the aluminum alloy strip or tube are covered with a booth having a height of 500 mm, a width of 500 mm, and a length of 800 mm. The inside temperature of the booth was changed as described above, and a nitrogen gas supply device was provided so that the inside of the booth could be replaced with nitrogen gas.

[0075]

[Table 4]

The same tube and strip as in Example 1 were coated with the brazing alloy having the composition shown in Table 5 under the conditions shown in Table 5.

[0077]

[Table 5]

With respect to these brazing material-coated tubes, this multi-hole tube was cut into a length of 580 mm, and the plate thickness was 0.07 mm.
JIS3903 alloy fins with corrugated mm
The heat exchanger core shown in FIG. 1 was assembled in combination with the 3003 alloy header pipe. A boride flux is applied to the assembled core, and the core is heated at 595 ° C. × 3.5 in a nitrogen atmosphere.
The brazing was performed under the heating condition for minutes. Table 6 shows the results of observing the appearance of the core after brazing and examining whether a local unattached portion has occurred.
Shown in Further, the first core was cut out of 20 fins from a portion where no unattached portion was formed, and the brazing state was determined by the fin adhesion rate. That is, the fin material is peeled off from the tube material, and the completely adhered material is bonded at a rate of 100%.
For those having an unbonded portion, the ratio (length of the bonded portion) / (length of the bonded portion + length of the non-bonded portion) was set to 100 times to obtain the bonding ratio (%). Table 6 shows the results. In addition, one core was subjected to a CASS test to examine corrosion resistance.
Table 6 shows the test results.

The strips were cut to a width of 16 mm and a length of 200 mm, and corrugated according to JIS3 having a thickness of 0.07 mm.
A single core was assembled in combination with the 903 alloy fin. A boride flux was applied to the obtained core and brazed under a heating condition of 595 ° C. × 3.5 minutes in a nitrogen atmosphere.

[0080]

[Table 6]

The tube manufactured by the apparatus of the present invention has no local unbonded portion, has a high fin joining rate, has a good corrosion resistance, and the strip manufactured by the apparatus of the present invention has a brazing property. Is good.

(Embodiment 3) In the apparatus of the present invention,
An example in which the tube is coated with the following brazing filler metal by changing the shape and the material of the spray nozzle variously will be described. A hot-extruded JIS 1050 aluminum multi-hole flat tube was blasted in a cold state and then made into a coil. The brazing material shown in Tables 7 to 9 was heated to a temperature higher than the melting point by 100 ° C. or more, and the pressure was 30 kg / cm ² and the spray nozzle having the shape shown in the table was used. And sprayed continuously. The distance between nozzle and tube is 100mm
The line speed of the coil was changed in accordance with the amount of molten metal jetted, so that the amount of adhesion was about 40 g / m ² . At that time, the spray state of the brazing material ejected was examined. In addition, the cross section of the multi-hole pipe material was micro-observed, the thickness of the attached brazing material was measured, and the difference between the maximum value and the minimum value of the brazing material thickness was obtained. The results are shown in the same table.

The obtained multi-hole tube was cut into a length of 580 mm, and corrugated according to JIS 390 having a thickness of 0.07 mm.
The heat exchanger cores shown in Table 1 were assembled in combination with the 3 alloy fins and the 3003 alloy header pipe. A boride flux was applied to the assembled core and brazed under a heating condition of 595 ° C. × 3.5 minutes in a nitrogen atmosphere. The results of observing the appearance of the core after brazing and examining whether a locally unattached portion has occurred are shown in the same table.

[0084]

[Table 7]

[0085]

[Table 8]

[0086]

[Table 9]

When the spray nozzle of the present invention is used, the spray state of the brazing material is good. Furthermore, in Examples Nos. 20 to 49 of the present invention using a core made of a pipe material in which a brazing film was formed using the spray nozzle of the present invention, the difference between the maximum value and the minimum value of the film thickness was 30 μm or less, No unattached portions are generated, and the brazing property is good. On the other hand, in Comparative Examples 50 to 58 and Conventional Example 59, the difference between the maximum value and the minimum value of the film thickness was 50 μm.
As described above, a locally unattached portion has occurred, and a problem has occurred in brazing properties.

[0088]

As described above, according to the present invention, it is possible to form a uniform brazing film having excellent brazing properties on the surfaces of aluminum alloy strips and aluminum alloy tubes. It has.

[Brief description of the drawings]

FIG. 1 is a front view showing a parallel flow type condenser.

FIG. 2 is a partially enlarged front view showing a core crack generated in a brazed heat exchanger core.

FIG. 3 is a view for explaining a mechanism of the occurrence of a core crack. () Is an explanatory view showing a contact state between the tube and the fin when a core is assembled by combining a tube sprayed with a brazing material and a fin, and (C) is an explanatory view showing a fillet portion of the tube and the fin after brazing. It is.

FIG. 4 is an explanatory view showing an example of the device of the present invention.

FIG. 5 is a sectional view showing a spray nozzle used in the apparatus of FIG.

FIG. 6A is an explanatory diagram illustrating a spray pattern of a spray nozzle, and FIG. 6B is an explanatory diagram illustrating various spray patterns.

FIG. 7 is an explanatory view showing another example of the device of the present invention.

8 is a sectional view showing a spray nozzle used in the apparatus of FIG.

FIG. 9 is an explanatory view showing still another example of the present invention.

FIG. 10 is a sectional view showing an example of a spray nozzle used in the apparatus of the present invention.

FIG. 11 is a sectional view of the same.

FIG. 12 is a sectional view of the same.

[Explanation of symbols]

 Reference Signs List 1 tube 2 fin 3 header pipe 4 side plate 5 local unattached portion 6 brazing material layer of brazing sheet 7 tube surface 8 maximum attachment height of brazing 9 brazing material layer formed by thermal spraying 10 brazing material fillet 11 brazing Position substantially corresponding to the front tube surface 15 Brazing material melting device 16 Piston 17 Pressurizing device 18 Spray nozzle 19 Pressurizing source 20 Heater 21 Heating device 22 Nozzle tip 23 Inert gas 24 Aluminum alloy strip or tube 25 Booth 26 Crucible 27 Heater 28 Refractory material 29 Pipe for supplying molten metal to cylinder 30 Cylinder 31 Portion for pressurizing molten metal 32 Outlet for molten metal 33 Pipe for supplying molten metal to nozzle 34 Near nozzle of pipe for supplying molten metal to nozzle 35 Passage through which molten metal passes 36 Pipe and Nozzle adapter Tar 37 O-ring 38 Portion of gas atmosphere 39 Distance from nozzle tip to tube or strip 40 Grooved roll for positioning tube or strip 41 Unwinder 42 Rewinder 43 Surface orthogonal to spray direction 44 Plane Typical spray pattern 45 Melting and pressurizing device 46 Pressure regulating valve 47 Gas supply device 48 Pressure accumulator tank 49 Open / close valve 50 Heating device 51 Brazing filler port 52 Open / close valve 53 Filtration filter 54 Brazing filler pipe 55 Gas inlet pipe 56 Gas discharge pipe 57 Guide Roll 58 Inert Gas Introducing Tube 59 Heater 60 Spray Nozzle Orifice 61 Molten Metal Filtration Unit 62 Nozzle Tip 63 Minimum Cross Section Area Molten Metal Passing Port 64 Molten Metal Diffusion Unit

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI C23C 4/12 C23C 4/12

Claims (15)

[Claims] 1. A pressurizing device for holding a molten aluminum alloy and pressurizing the same while maintaining the temperature at a high temperature, and, if necessary, a molten metal heating section provided in a molten metal flow passage before and after the pressurizing device. A spray nozzle for uniformly dispersing and spraying the pressurized molten metal, a nozzle heating device provided as necessary, and aluminum coated with the aluminum alloy at a distance of 10 to 250 mm from the tip of the spray nozzle An aluminum alloy coating device comprising an alloy material. 2. A pressurizing device for holding a molten aluminum alloy braze and pressurizing the same while maintaining the temperature at a high temperature, and, if necessary, a melt heating unit provided in a melt flow passage before and after the pressurizing device. A spray nozzle for uniformly dispersing and spraying the pressurized molten metal, a nozzle heating device provided as needed, and an aluminum alloy brazing material coated at a distance of 10 to 250 mm from the tip of the spray nozzle. An aluminum alloy coating device comprising an aluminum alloy strip or aluminum alloy tube for a heat exchanger member made of an aluminum alloy. 3. An aluminum alloy brazing material comprising: Si:
3. The aluminum alloy coating apparatus according to claim 2, wherein 50 wt%, Zn: 40 wt% or less, the balance being aluminum and unavoidable impurities. 4. The amount of the aluminum alloy brazing material coated on the surface of the aluminum alloy strip or aluminum alloy tube for a heat exchange member made of aluminum alloy is 5 to 50 g / m ^2.
The coating device for an aluminum alloy according to claim 2 or 3, wherein 5. The aluminum alloy coating apparatus according to claim 1, wherein the molten metal is ejected from the spray nozzle at a rate of 4 to 500 g / min. 6. The pressurizing device according to claim 1, further comprising a heat retaining device for keeping the temperature of the molten metal at a temperature higher than the melting point of the aluminum alloy brazing material by 150 ° C. or more. A coating apparatus for the aluminum alloy according to the above. 7. The aluminum alloy coating apparatus according to claim 1, wherein a filter for removing impurities in the molten metal is provided between the pressurizing device and the spray nozzle. 8. An injection nozzle for an inert gas which covers the tip of the spray nozzle with an inert gas is provided at the tip of the spray nozzle, and further, the inside of the spray region of the molten metal sprayed from the spray nozzle is replaced with the inert gas. The aluminum alloy coating apparatus according to any one of claims 1 to 7, further comprising a booth. 9. The aluminum alloy coating apparatus according to claim 8, wherein the inside of the booth can be heated to 200 to 550 ° C. and heating is performed as needed. 10. A cylinder and a piston are used as means for pressurizing the molten metal, and the piston is used to press the molten metal by 1 to 30 M.
The aluminum alloy coating device according to any one of claims 1 to 9, wherein a pressure device that pressurizes at a pressure of Pa is used. 11. The aluminum alloy coating apparatus according to claim 1, wherein the molten metal is pressurized at a pressure of 0.1 to 10 MPa using a direct pressurization method using gas as a means for pressurizing the molten metal. 12. The spray nozzle has a tip with a depth of 0.1 to 0.1.
A V-shaped or U-shaped groove having a cross section of 3.0 mm is formed, and the minimum cross-sectional area through which the pressurized molten metal passes at the bottom of the groove is 0.0 mm.
Coating apparatus of the aluminum alloy of any one of claims 1 to 11 and has a through hole of 01~0.05mm ^2. 13. The material of the tip of the spray nozzle is at least one of silicon carbide, tungsten carbide, carbon, alumina, magnesia, zirconia, silica, calcia, yttria, boron nitride, silicon nitride, and aluminum nitride. Or
The aluminum alloy coating apparatus according to any one of claims 1 to 12, wherein the apparatus is a mixture of two or more of these. 14. A method for holding the molten aluminum alloy at a temperature higher than the melting point of the aluminum alloy brazing material by 150 ° C. or more in a pressurizing device containing the molten aluminum alloy brazing material, or further, in a molten metal flow passage before and after the pressing device. Is heated at a pressure of 0.1 to 30 MPa by the pressurizing device, and the molten aluminum alloy brazing material is uniformly supplied from the spray nozzle at a rate of 4 to 500 g / min. Coating of aluminum alloy brazing material characterized in that aluminum alloy brazing material of 5 to 50 g / m ² is adhered to the surface of aluminum alloy strip or aluminum alloy tube for aluminum alloy heat exchanger member by dispersing and spraying. Method. 15. A pressurizing device containing a molten aluminum alloy brazing material, wherein the molten metal is kept at a temperature higher than the melting point of the aluminum alloy brazing material by 150 ° C. or more, or further in a molten metal flow passage before and after the pressing device. Is heated at a pressure of 0.1 to 30 MPa by the pressurizing device, and the molten aluminum alloy brazing material is uniformly supplied from the spray nozzle at a rate of 4 to 500 g / min. An aluminum alloy strip for an aluminum alloy heat exchanger member and an aluminum alloy tube, wherein an aluminum alloy brazing material of 5 to 50 g / m ² is adhered to the surface by dispersing and spraying.