JPS588928B2 - Seizouhouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for easily manufacturing a multi-path pipe used in a heat exchanger, that is, a pipe in which a large number of pipes are connected in parallel with fins sandwiched between them. .

In general, a multi-channel pipe is composed of a large number of pipes integrally provided, so the cross-sectional area of each pipe is small relative to the cross-sectional area of the entire pipe, and the pipe surface area is relative to the cross-sectional area of the pipe. The multi-channel pipe is widely used in heat exchangers and the like because it is extremely advantageous in terms of strength and heat exchange.

Conventionally, the above-mentioned multi-channel pipe has been manufactured by extrusion molding, brazing joining of single pipes (ERW pipes, seamless pipes), and the like.

However, it is difficult to manufacture thin-walled pipes with a wall thickness of 1 mm or less using extrusion molding, and the method of joining many single pipes requires complicated brazing work for joining in addition to forming the pipes. However, there are many problems in terms of manufacturing time and cost.

This invention uses a tube whose inner surface is coated with a brazing material (its cross section may be either round or square), presses the tube to simultaneously form a plurality of pipes, and then removes the parts other than the pipes. That is, the present invention provides a completely new method for manufacturing multi-channel pipes in which the parts that will become wine are joined by vacuum brazing.

According to this method, a large number of tubes constituting a multi-pipe line can be molded at the same time, and the brazing operation at the time of joining is extremely simple, making it possible to reduce the manufacturing cost by one order of magnitude.

In addition, the wall thickness of the pipe can be made as thin as necessary, which has many advantages in terms of saving materials and improving heat exchange efficiency.

FIGS. 1 and 2 are schematic cross-sectional views of pipes for explaining the method of this invention.

First, the tube material (usually made of aluminum alloy)
1 has a round shape (FIG. 1A) or a square shape (FIG. 2A), and its inner surface is coated with a brazing material 2.

Press this and open the openings shown in Figures 1 and 2 respectively.
It is molded sequentially as shown in 2.

A conduit 3 and a joint portion (fin portion) 4 are formed.

When it has the shape shown in Figure 2, it is placed in a vacuum furnace under normal vacuum brazing conditions (e.g. degree of vacuum: IX10 -5
torr, temperature: 600° C., processing time: 1 hr), and the fin portions 4 are bonded tightly.

In this way, since the material tube 1 is coated with a brazing material, there is no need to insert additional brazing material during joining.

Also, unlike brazing using normal flux, defects in the joint due to flux entrainment (deterioration in mechanical strength and corrosion resistance) do not occur.

Although the figures show multi-pipe lines with round and rectangular cross sections, any other shape can be manufactured by simply changing the press mold.

Furthermore, if necessary, it is also possible to provide a partition or other work within the multiple conduits.

[Brief explanation of the drawing]

FIGS. 1A-2 and 2A-2 are schematic cross-sectional views showing the steps of the multi-channel pipe manufacturing method of the present invention. In the drawing, 1... Material tube, 2...
...Brazing metal coating, 3...Pipe line, 4...
・Joint part (fin part).

Claims (1)

[Claims] 1. A round tube or a square tube whose inner surface is coated with a brazing material is used as a material, the tube is pressed to simultaneously form a plurality of conduits and fin portions, and then the tube A method for manufacturing a multi-channel pipe for a heat exchanger, characterized in that fin portions other than the channels are joined by vacuum brazing using the inner surface coating brazing material.