JPS63194194A - Fin member made of aluminum - Google Patents

Abstract

PURPOSE:To reduce cost and improve the property of mass-production in the case of manufacturing a heat exchanger prominent in drain discharging performance, by a method wherein a water repellent film is formed previously on the local part of a fin member made of plate type aluminum, which is projected upon forming. CONSTITUTION:A fin member 1, made of hoop type aluminum, is reformed into a flat sheet and water repellent films are formed locally on the surface of the flat fin member. The forming areas of the water repellent film are formed continuously in the shape of a plurality of parallel lines in the feeding direction of the member 1, as shown by shaded lines S in a diagram, together with the feeding of the blank material. Hydrophilic film are formed on the areas U except the water repellent film forming areas S. Penetrating holes 2 for penetrating refrigerant pipes are formed on the fin member 1, made of aluminum, with predetermined intervals. In this case, a flared part 4 is formed around the penetrating hole 2 and, then, the material is cut to make a fin 10. A multitude of the fins 10 is accumulated and refrigerant pipelines 3 are penetrated through the penetrating holes whereby a flat fin type heat exchanger may be constituted. A water repellent film is formed on the lower surface of the flared part 4, whereat water drips are stagnated, therefore, the adhesive force of the water drips is reduced and drain may drop under its own weight.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an aluminum fin material used as air cooling fins when constructing a plate-fin heat exchanger in an air conditioner, for example. It is.

(Prior Art) Aluminum plates or aluminum alloy plates are used as materials for plate-fin heat exchangers used in, for example, air conditioners, from the viewpoints of thermal conductivity, corrosion resistance, light weight, and the like. When such a heat exchanger acts as an evaporator, moisture in the atmosphere condenses and adheres to the fin surface as water droplets. If such water droplets, so-called condensate, remain on the ventilation path of the heat exchanger, the heat exchange characteristics will be impaired, so it is necessary to quickly drain the generated condensate.

For this purpose, for example, Japanese Patent Application Laid-Open No. 59-185996 discloses that a hydrophilic film is formed on the entire surface of the fins constituting the plate-fin heat exchanger, thereby reducing the amount of condensate remaining on the fin surfaces. It is done like this.

FIG. 4 shows a schematic cross-sectional view of the plate-fin type heat exchanger, and as shown in the figure, each fin 41 made of thin aluminum plates is placed upright at a predetermined distance from each other. By forming a hydrophilic coating on their surfaces, the drainage generated can be
As shown in (A) in the figure, the water no longer stagnates in a so-called bridge state, but quickly flows down along the vertical plane, making it possible to reduce the amount of residual drain.

(Problems to be Solved by the Invention) On the other hand, in the plate-fin type heat exchanger as described above, as shown in FIG. The fins 41 are assembled in a state where the fins 41 are inserted approximately horizontally, and there is a problem in that drain generated and deposited in the horizontal portions between these fins 41 tends to remain without being drained. This horizontal portion has a bulging edge (hereinafter referred to as
The drain generated in the outer cylindrical flare portion 44 accumulates in the form of water droplets as shown in (B) in Fig. 4 below. That's what I do. There is an adverse effect of the hydrophilic treatment in that the higher the hydrophilicity of the flared portion 44, the larger the water droplets become.As the drain remains along the horizontally arranged refrigerant pipe 42, There was a problem that ventilation resistance increased and heat exchange efficiency decreased.

Especially if such drain freezes, a large amount of heat for defrosting will be consumed in the residual drain during defrosting operation, which will lengthen the defrost time and impair air conditioning comfort. The result was that

Therefore, by forming a water-repellent film on the lower surface of the flared portion 44 of each fin 41, conventionally, by forming a water-repellent film on the lower surface of the flared portion 44 of each fin 41, the water-repellent film remains at that position in a size commensurate with the adsorption force acting from the surface of the flared portion. The adsorption force of the water-repellent film is extremely small, so the water droplets fall off due to their own weight, and therefore, water droplets do not remain as they did in the past.As a result, it is possible to further reduce the amount of residual drainage. becomes.

However, it is not possible to form a water-repellent film locally on the cylindrical surface of the flared portion that protrudes from the main plane of the plate-like fin as described above using conventional manufacturing processes. If we assume the process of manually applying water-repellent paint to a cylindrical local area as described above, several hundred fins would be required for each heat exchanger.
The manufacturing cost will increase significantly.

This invention has been made in view of the above, and its purpose is to reduce cost increase and improve mass productivity, for example, when manufacturing a heat exchanger with excellent drain drainage performance as described above. The object of the present invention is to provide a fin material made of aluminum (hereinafter, "aluminum" in the present invention includes aluminum alloys).

(Means for Solving the Problems) Therefore, the aluminum fin material of the present invention is a plate-shaped aluminum fin member 1, in which a water-repellent film is formed in advance on a local portion that is to be protruded.

(Function) In the above-mentioned aluminum fin material, a water-repellent film is formed in advance on the local part to be protruded, so for example, as mentioned above, the water-repellent film is formed on the underside of the flared part to be protruded into the fin. When constructing a heat exchanger with excellent drain drainage performance by forming a film, the area below the flared portion is determined on the plate-shaped material before extrusion molding, and this area is used as the water exchanger. (As a result, the process after the above-mentioned protrusion molding is simply alignment to the above-mentioned film formation area, and no extra manufacturing process is added, so it can be applied to the conventional manufacturing process.) In addition, when forming a water-repellent film, since the target material shape is a flat plate, it is possible to mass-produce it using printing methods, for example, and therefore, it is possible to manufacture heat exchangers with excellent drain drainage performance. In doing so, it is possible to reduce cost increase and improve mass productivity.

(Embodiments) Next, specific embodiments of the present invention will be described in detail with reference to the drawings.

FIGS. 1(a) to (d) show the process for manufacturing fins that have a water-repellent film locally on the flared portion around the through hole in the fins constituting the plate-fin type heat exchanger as described above. The manufacturing process is shown, and the aluminum fin material according to the present invention is shown in the same figure (b).

That is, the hoop-shaped aluminum fin material 1 shown in FIG. 2(a) is straightened into a flat plate shape, and a water-repellent film is locally formed on its surface as shown in FIG. 2(b). This water-repellent film forming area is continuously formed in a plurality of lines parallel to the feeding direction as the material is fed, as shown by the hatched area S in FIG. That is, after applying a silicone polymer or fluorine-based water-repellent paint by printing or the like, a predetermined baking process is performed using a dryer or the like to form a water-repellent film with a thickness of 2 to 50 μm. The above-mentioned line spacing is the width of the fins, which will be described later, plus a cutting allowance, and the line width is slightly smaller than the through hole diameter, which will be described later. After forming the water-repellent film, a hydrophilic film is then formed on the area U other than the film-forming area S, including the entire back surface. Similar to the formation of the water-repellent film described above, for example, a hydrophilic paint made of acrylic resin containing a surfactant, synthetic silica, etc. is applied by printing, and then baked.
A hydrophilic film is formed in a region U other than the water-repellent film forming region S.

The aluminum fin material 1 on which the water-repellent film has been locally formed in this way is then sent to the hole-forming process shown in FIG. 1(C). Then, as shown in the figure, through holes 2 for inserting refrigerant pipes are bored at predetermined intervals. At this time, as will be described later, a flared bulge edge, that is, a flare portion, is formed around the through hole 2 by drawing in a step before or after the step of drilling the through hole 2. Above through hole 2
The centers of each line are made to coincide with the center of the line of the water-repellent film. After that, the lot line 11 shown in FIG. 1(C)
．． By cutting along the fins 12, the fins 10 as shown in FIG. A plate-fin type heat exchanger as shown in is constructed.

At this time, the water-repellent coating surface S is a line extending vertically including the center of each through hole 2, as shown in FIG. , a flared portion 4 protruding from the main plane 5 of the fin lO
In this case, the water-repellent coating is formed on the upper and lower parts of the outer peripheral surface of the cylinder. This flare portion 4 maintains the spacing between the fins 10 in the assembled state shown in FIG. 2, and also maintains the orthogonal mounting state of each fin 10 with respect to the refrigerant pipe 3.

In the plate-fin heat exchanger configured as described above, when it is used as an evaporator, water droplets that adhere to the fins 10 due to condensation of moisture in the atmosphere, so-called drain, are treated as follows. It has an effect. First, since a hydrophilic film is formed on the vertically disposed surface of the fin 10, the drainage generated in this area does not become large water droplets or remain in a bridge state between adjacent fin members, and the above-mentioned As in the conventional example, it quickly flows down along the vertical plane. And in the above configuration,
Drain adhering to the flare portion 4 in the horizontally arranged state also drips quickly without turning into large water droplets. In other words, in the conventional example in which the flared portions 4 were also subjected to hydrophilic treatment, the drain would collect and remain as water droplets at the lower side of each flared portion.
The size of the water droplet depends on the magnitude of the adsorption force acting on the water droplet from the surface of the flared portion. When hydrophilic treatment has been performed, the adsorption force is large, and therefore, the water stays in the form of large water droplets. However, in the above embodiment, a water-repellent film is formed on the flared portion 4, especially on the lower side where water droplets accumulate, and therefore the adsorption force is significantly reduced, so that large water droplets do not remain in that position. As a result, the drain will fall due to its own weight.

For these reasons, in the plate-fin type heat exchanger in the above embodiment, the amount of residual drain is reduced, and therefore the increasing force 5 of ventilation resistance in the heat exchanger is suppressed, so that the heat exchange performance is maintained and improved. becomes possible.

For example, in a separate air conditioner, during heating operation in winter, frost forms on the heat exchanger in the outdoor unit that acts as an evaporator, and a defrost operation is required to remove this frost. In the heat exchanger, when the condensate adhering to the flared portion along the refrigerant piping becomes frozen, a large amount of defrosting heat is required to thaw the condensate. In the embodiment described above, residual water in the flare portion 4 is suppressed, so the amount of heat required for defrosting is reduced, and as a result, defrosting is completed in a short time, improving air conditioning comfort.

As explained above, by forming a water-repellent film locally on the surface of the flared portion that bulges out from the main plane of the plate-like fin,
When constructing a heat exchanger with excellent drainage performance, by using an aluminum fin material with a water-repellent film formed in advance on the local area corresponding to the flared part, the process after drilling and forming can be done in the area where the film is formed. By simply aligning the positions, no other extra manufacturing steps are added, and the method can be applied to conventional manufacturing steps. Also, in the formation of the above-mentioned water-repellent film, since the target material shape is a flat plate, mass production by, for example, printing is possible. Therefore, for example, in manufacturing a heat exchanger with excellent drainage performance, it is possible to reduce cost increase and improve mass productivity.

In addition, in the above example, when forming a water-repellent film, an example is explained in which the paint is applied continuously in a line shape, which makes the application process easier and the positioning with the through hole easier. I gave an example, but for example,
As shown in Figure (a), a region Sa including the entire flare portion 4,
Alternatively, as shown in FIG. 3(b), the shape regions corresponding to the lower regions sb of the flare portion 4 were determined in advance for the flat material state, and water-repellent films were formed at intervals in the material feeding direction. It can also be taken as a thing. Further, in the above embodiments, the step of forming a hydrophilic film was explained after forming the water-repellent film, but these steps may be interchanged, and the step of forming a hydrophilic film can be replaced with, for example, a step of forming a hydrophilic film. When forming a coating film using a turbid aqueous solution of the coating material, even if the entire fin is immersed in the aqueous solution, water will be repelled in areas where a water-repellent coating has been previously formed. As a result, it is possible to prevent the hydrophilic film from being selectively formed on the leprosy film, so after drilling the through holes or assembling the refrigerant piping, it is possible to prevent the formation of a hydrophilic film on the leprosy film by immersion in the aqueous solution as described above. It is also possible to form a hydrophilic film. Further, in the above example, the aluminum fin material 1 is used in a heat exchanger, but it can be similarly applied to various other devices.

(Effects of the Invention) As described above, in the aluminum fin material of the present invention, for example, a water-repellent film is provided on the lower side of the flared portion that bulges out from the main plane of each fin. When constructing an exchanger, since a water-repellent film is locally formed on the plate-shaped material in advance, subsequent hole forming can be applied to the conventional manufacturing process.
In addition, in the formation of the above-mentioned water-repellent film, since the target material is a flat plate, it is possible to mass-produce it by, for example, printing. It is possible to improve sexual performance.

[Brief explanation of the drawing]

Figures 1 (a) to (d) are schematic diagrams showing the process of manufacturing heat exchanger fins using aluminum fin material in an embodiment of the present invention, and Figure 2 is a schematic diagram showing the process of manufacturing fins for a heat exchanger using the above fins. FIGS. 3(a) and 3(b) are partial perspective views of fins made from aluminum fin material in other embodiments of the present invention; FIG. 4 is a schematic diagram illustrating the state of condensate adhesion in a conventional heat exchanger. 1... Aluminum fin material. Patent applicant: Daikin Industries, Ltd. No. 1
Figure (Q) (b) (C) (d) Figure 2

Claims (1)

[Claims] 1. An aluminum fin member (1) in the form of a plate, characterized in that a water-repellent film is formed in advance on a local portion to be protruded.