JPS60137566A - Production of heat exchanging tube provided with aluminum fin - Google Patents

Abstract

PURPOSE:To produce a titled heat exchanging tube with improved productivity, reduced equipment cost, etc. by inserting successively alternately fins and spacers onto the tube then brazing the fins and spacers to the tube. CONSTITUTION:Al fins 2 consisting of brazing sheets each having a tube insertion hole 4 and short cylindrical Al spacers 3 are alternately and successively inserted onto a metallic tube 1 in the state of maintaining contact with each other. The assembly is subjected to brazing in this state, by which the assembly is joined in the state of packing the brazing filler metals 2b possessed by the above-described brazing sheets between the tube 1 and the fins 2 as well as the tubes 3. The heat exchanging tube provided with the Al fins is thus produced with good productivity.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method of manufacturing a heat exchanger dibe having a plurality of fins made of nofluminium arranged in parallel.

In this specification, the terms C and aluminum are used to include their alloys.

(Prior Art) Conventionally, press-fitting has been most commonly used for heat exchange tubes that are equipped with a large number of aluminum fins on the outer periphery of a tube made of stainless steel, copper, or the like. That is, as shown in Fig. 6, an aluminum disc-shaped fin (12) with a collar part (1, 2a) is forcibly attached to the outer periphery of a tube (11) made of stainless steel or the like from one end. A method of fixing was used by press-fitting the

However, this press-fitting method requires a special equipment cost for the press-fitting device, and the press-fitting operation requires relatively time and effort, resulting in high manufacturing costs. In addition, the fin (12) is forcibly fitted onto the outer periphery of the tube (11) whose diameter is slightly larger than the inner diameter of the collar portion (12a) to tightly fix the two. During this press-fitting, a portion of the collar of the fin may break, and if this breakage occurs, there is a great possibility that the contact between the fin and the tube will be incomplete and the heat exchange efficiency will be significantly reduced. Furthermore, the pitch of the fins tends to be irregular, resulting in poor appearance.

(Objective) The present invention aims to provide a method for manufacturing an aluminum finned heat exchange tube that can solve the above-mentioned problems.

For the above purpose, as shown in the illustrated embodiment, the present invention has an aluminum fin (2) made of a plating sheet having a tube insertion hole (4), and a short cylindrical aluminum spacer (2). 3) and 3) are sequentially inserted into the outer periphery of the metal tube (1) alternately and in contact with each other, and then brazing is performed 1 to connect the brazing material (2b) of the plating sheet to the tube (1). and Finn (
2) and a spacer (3), the present invention presents a method for manufacturing a heat exchange duplex equipped with aluminum fins, which is characterized in that the aluminum fins are joined in a filled state between the aluminum fins (2) and the spacer (3).

The metal tube (1) is made of copper, iron, aluminum, or the like.

In addition, the fin (2) is made of a Δρ-Mn alloy as a core material (2a
) and △a as brazing material (skin material) (2b) on both sides.
-Aluminum brazing clad with S+ alloy is used.

Furthermore, the spacer (3) is formed into a cylindrical shape with a length corresponding to the desired fin pitch, and is made of, for example, A6063.
Eight ρ-M (l-based alloys) such as alloys are used.

A tube insertion hole (
4) and space 1+-(3) are both tube (
It is desirable that the outer diameter of the tube (1) be slightly larger than the outer diameter of the tube (1) by, for example, about 1 mm, so that it can be easily inserted into the tube (1).

Therefore, in carrying out the present invention, after degreasing each of the above-mentioned members with an organic solvent or the like, first, as shown in FIG.
and are alternately inserted and brought into contact with each other to form an assembly as shown in FIG. At this time, make sure that the fins (2) and spacers (3) do not shift on the tube (1).
Insert a stopper into the tube as appropriate.

The above assembly is then brazed together. This solder can be preferably vacuum-brazed by a vacuum brazing method, but is not limited thereto, and any other brazing method such as a dip brazing method may be employed.

Brazing (use J3 at the time of brazing and brazing the above assembly)
When heated above the melting point of IJ (2b) on the surface of the fin (2), the brazing material (211>
As shown in FIG. 3, the melt melts, and initially, as shown in FIG. When the heated state is further maintained, the molten wax U (21)) further flows and spreads on both the inner and outer surfaces of the spacer (3), and is deposited into the gap (C) between the tube (1) and the spacer (3). It is filled to the brim. Therefore, when the tube (1), fin (2) and spacer (3) are cooled,
They are bonded while maintaining perfect contact in terms of heat transfer, and the desired product J shown in FIG. 5 can be obtained.

Note that during the above cooling, if the tube (1) is made of a different metal such as stainless steel, which has a smaller coefficient of thermal expansion than the aluminum fins (2) and the spacer (3), the tube (1) ) by applying a tightening compressive force by the fins (2) and spacers (3) to further firmly and reliably join and fix them in a close contact state.

According to the present invention, the desired product can be obtained by sequentially and alternately fitting fins and spacers around the outer periphery of the tube and then brazing them, as described above. Product costs can be reduced by improving productivity and reducing equipment costs. In addition, since the fins and the spacer V- are fixed to the outer circumference of the tube while maintaining perfect thermal contact, it is possible to obtain a product with stable and excellent heat exchange performance, and the fin pitch is ensured by the spacer. Since the fin pitch is properly regulated, it is possible to obtain a product with a uniform fin pitch and a comparable appearance. Furthermore, since the fins and spacers are interchangeable, the fin height and fin pitch can be arbitrarily determined, which has the advantage of being able to respond freely to changes in design specifications.

Next, an embodiment of the present invention will be described.

The tube (1) is made of stainless steel with an outer diameter of 19 m and a wall thickness of 1°6 #, and the fin (2) uses A3003 alloy for the core material (2a) and A4003 alloy for the brazing material (2b). It was made of plating sheet with cladding on both sides. And the shape of the fin (2) is 1.0 mm in thickness and 59 in outer diameter.
The diameter of the tube insertion hole (4) was 19.11 nlK. In addition, the spacer (3) is made of 6063 alloy, has a length of 6.0 am, an outer diameter of 21.0 mm, and an inner diameter of 1 mm.
9.111 (F) A short cylindrical one was used.

Then, the fins (2) and spacers (3) are alternately fitted onto the outer periphery of the tube (1) and temporarily fixed in contact with each other to form an assembly, which is then heated to a temperature of 605
Vacuum brazing was performed at ℃ according to a conventional method.

However, the fins (2) and spacers (3) are firmly fixed to the outer periphery of the tube (1) in a completely intimate state, the fin pitch is uniform, and both the inside and outside surfaces of the tube require post-cleaning treatment. Could get a finned tube that doesn't.

[Brief explanation of the drawing]

The drawings show the embodiment of this invention in the order of steps.
The figure is a cross-sectional view showing the state in which the fins and spacer are being fitted into the tube, Figure 2 is a cross-sectional view showing the state of the assembly after fitting the above and before the brazing number, and Figure 3 is a heated brazing Fig. 4 is a sectional view showing the state after brazing, Fig. 5 is a perspective view of the product, and Fig. 6 is a sectional view showing the initial state.
The figure is a cross-sectional view showing a manufacturing state by a conventional press-fitting method. (1>...dupe, (2)...fin, (2a)
... Core material, (2b) ... Brazing material, (3) ... Spacer, (/I) ... Tube insertion hole. Above Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] 1-1 = Aluminum fins made of plating sheets with nib holes and short cylindrical aluminum spacers (after sequentially inserting them into the outer periphery of the metal tube alternately and in contact with each other, The brazing seam I-4 is characterized in that the brazing seam I-4 is bonded and covered with a brazing material filled between the tube, the fins and the substrate 4) by applying solder F4. This is a method for manufacturing heat exchange tubes.