JPS5824684A - Manufacture of aluminum-copper joint pipe for heat exchanger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a cooling unit 1 for a refrigerator or the like. This invention relates to a method for manufacturing aluminum-copper joint pipes for heat exchangers used for piping between compressor units and compressor units.

Normally, aluminum pipes are used for the internal piping of the cooling unit (evaporator), and compressors,
Steel pipes are used for the internal piping of Saruni and Soto.
Generally, steel pipes are used for the refrigerant circulation piping that connects the outlet pipes of both units. However, copper and aluminum are metals that are very difficult to join, and there is no problem when joining the outlet pipe of the compressor unit and the copper pipe because there is a copper phase pressure. When joining a lead pipe and a steel pipe, it is difficult to achieve robust and reliable brazing.

Therefore, the present invention aims to provide a method for manufacturing a copper-aluminum joint pipe for a heat exchanger that enables mutual bonding of copper phase pressure and aluminum, in order to obtain a highly reliable and sound piping joint between both units. The purpose is to achieve a sound bond between a steel pipe and an aluminum pipe by applying an adhesive, rather than using pressure welding or the like.

That is, as shown in FIGS. 1 to 8, first, the end surface of the copper tube 1 is coated with aluminum plating 2 by ultrasonic plating.
administer. Ultrasonic plating is a method in which metal is immersed in an aluminum plating bath and plating is applied to the aluminum plating bath in contact with the metal or by applying ultrasonic vibrations to the metal. The aluminum plating coating 2 is applied over a predetermined length of the tube end. When using ultrasonic plating for aluminum plating, an extremely dense and robust aluminum plating layer can be obtained.

As described above, a copper tube 1 whose tube end surface is coated with aluminum plating 2 is prepared in advance, and the tube end of the copper tube 1 and the tube end of the aluminum tube 3 are inserted into each other to connect them. The aluminum plated coating 2 is interposed over the entire length of the part so that the aluminum plated coating 2 and the aluminum tube 3 are in close contact with each other, and the contact surfaces of the aluminum tube 3 and the aluminum plated coating 2 are bonded via the adhesive layer 4. do. Therefore, the copper tube 1 and the aluminum tube 3 can be joined.

The adhesive 4 may be applied to the entire circumferential surface of the aluminum plating coating 2 applied to the end of the copper tube 1 or to the side of the aluminum tube 3 before the copper tube 1 is inserted. Epoxy resin is suitable as the adhesive.

The aluminum plating coating 2 is at least on both pipes 1.3
Preferably, as shown in the figure, the length of the aluminum plating coating 2 is longer than the insertion margin between the copper tube 1 and the aluminum tube 3, and the end of the aluminum plating coating 2 is coated over the entire length of the insertion margin. The portion 2' is made to extend to the part not covered by the aluminum tube 3. After the copper tube 1 and the aluminum tube 3 are bonded together as described above, paint is applied to the contact portion of the aluminum tube 3 and the copper tube 1, and this is covered with a paint coating 5.

In accordance with the spirit of the invention, FIGS. 1 to 6 show that the outer surface of the end of a copper tube 1 is coated with aluminum plating 2 using ultrasonic waves, and the end of the steel pipe coated with the aluminum plating 2 is used as the end of an aluminum pipe 3. 5 and 6 show the case where the inner surface of the aluminum tube 3 and the aluminum plating coating 2 are brought into close contact with each other by the adhesive layer 4. FIGS. forming an annular projection 6 located at the end and abutting against the end surface of the aluminum tube 3;
The insertion depth of both tubes 1 and 3 is regulated by the abutment, and the end surface of the aluminum tube 3 and the abutment surface of the protrusion 6 are bonded to the aluminum plating coated end 2' to form a bond. This shows the case where the sealing and corrosion prevention effects at the edges are improved.

Further, FIGS. 7 and 8 show an example of manufacturing an aluminum-copper joint tube for a heat exchanger in which the inner surface of the end of the copper tube 1 is coated with aluminum plating 2 and the adhesive bonded as described above is achieved in accordance with the spirit of the invention. . That is, an expansion joint part 7 is formed at the end of the copper pipe 1, an aluminum plating coating 2 is applied to the inner surface of the expansion joint part 7 using ultrasonic waves, and an aluminum pipe 3 is formed inside the expansion joint part 7 of the copper pipe 1. The case is shown in which the outer surface of the aluminum tube 3 and the aluminum plated coating 2 are brought into close contact with each other by inserting the aluminum tube 3 into the aluminum plated coating 2, and the aluminum surfaces in close contact with each other are bonded via the adhesive layer 4.

The aluminum tube 3 is inserted until its end surface abuts against the proximal end of the tube expansion joint 7, and the aluminum tube 3 is bonded to the aluminum coated end 2' at the abutting surface.

According to this joining structure, it is possible to use the copper tube 1 and the aluminum tube 3 having the same diameter.

Furthermore, FIGS. 9 and 10 show insertion joints 8 at both ends of the aluminum-copper joint pipes obtained in each of the above embodiments, in order to facilitate brazing with the sunrise pipes of the cooling unit and the compressor unit. This shows a case in which a pipe expansion joint part 9 is configured.

That is, either the insertion joint part 8 is inserted into the outlet pipes of the compressor/2 server unit side and the cooler unit side and brazed with the same material, respectively, or the respective sun outlet pipes are inserted into the expansion pipe joint part 9. This shows a configuration for brazing.

Since the coefficients of linear expansion of the copper tube 1 and the aluminum tube 3 are significantly different, even if they are directly bonded, the bonded portion is likely to peel off due to the influence of the refrigerant (shrinkage and expansion), but according to the present invention, the above As explained above, the copper tube 1 is coated with a robust aluminum plating coating 2 in advance, and the aluminum plating coating 2 is
Since the copper tube 1 and the aluminum tube 3 are inserted into each other through the aluminum tube 3 and the adhesion surfaces of the aluminum pieces are bonded together, the copper tube 1 and the aluminum tube 3 can be firmly bonded by bonding the aluminum pieces together, which has extremely good adhesion. The resulting aluminum-copper joint tube exhibits mechanical strength that is no different from bonding aluminum tubes to aluminum tubes. Furthermore, the above-mentioned structure completely blocks the infiltration of moisture and the like from the joint interface between the aluminum tube 3 and the copper tube 1, and the leakage of refrigerant, and exhibits good corrosion resistance. Therefore, it is possible to provide a highly durable joint pipe that can withstand years of use.

According to the present invention, it is possible to provide a highly reliable joint pipe of copper pipe 1 and aluminum pipe 3 by applying adhesive, and it is an alternative to the copper-aluminum expanded pressure weld joint pipe for heat exchanger piping that is currently being researched. This system can be put to practical use immediately, and the above-mentioned piping problems between the cooling unit and the compressor unit can be reliably solved. That is, by using the copper-aluminum joint pipe described above, the steel pipe on the compressor unit side and the copper pipe side of the joint pipe, and the aluminum pipe on the compressor side and the aluminum pipe side of the joint pipe can be joined using the same metals. , providing a robust and highly reliable piping connection that is highly corrosion resistant and can withstand years of use.
It is possible to effectively prevent unexpected accidents such as leakage of refrigerant due to poor connection, etc., and in addition, it is possible to provide a joint pipe that facilitates piping work between both units.

[Brief explanation of the drawing]

The drawings show an example of manufacturing a joint pipe for a heat exchanger according to the present invention,
Figure 1 is a partially cross-sectional side view of a steel pipe metal with aluminum plating coated on the outer surface of the tube end, and Figure 2 is a cross-sectional view of a joint tube with the above-mentioned steel tube inserted into an aluminum tube and glued together. 3 is a side view of the joint tube with paint coating, FIG. 4 is an enlarged cross-sectional view showing the bonded part of the joint tube, and FIGS. 5 and 6 are the same side view of the joint tube as shown in FIG. The structure shows an example in which a steel pipe is formed with an annular protrusion that butts against the end surface of an aluminum pipe. Figure 5 shows the state before the two pipes are inserted and bonded, and Figure 6 shows a cross-section of the bonded part of the joint pipe after bonding. 7 and 8 show an example in which the inner surface of the copper tube is coated with aluminum plating, and an aluminum tube is inserted into the copper tube and bonded. 8 is a cross-sectional side view showing the bonded portion of the joint pipe after bonding, and FIGS. 9 and 10 are the aluminum-copper joints obtained in each of the above examples. Fittings inserted into both ends of the tube,
It is a side view which shows the case where the pipe expansion joint part is formed and shows the joint part in cross section. 1... Steel pipe, 2... Aluminum plating coating, 3...
Aluminum pipe, 4. Adhesive layer, 5. Paint coating. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5? Figure 6 Figure 7 Figure 9 Figure 10

Claims (3)

[Claims] (1) Apply an aluminum plating coating to the end surface of the copper tube, insert the steel pipe end and the tube end of the aluminum tube into each other, and bring the aluminum plating coating and the aluminum tube into close contact with each other. A method for producing an aluminum-copper joint tube for a heat exchanger, characterized in that the contact surfaces of aluminum plated coatings are bonded via adhesive. (2) In the invention described in item 1, the method for manufacturing an aluminum-copper joint tube for a heat exchanger, characterized in that the aluminum plating coating is applied to the outer surface of the tube end of the steel tube. (3) The method for manufacturing an aluminum-copper joint tube for a heat exchanger according to the invention described in item 1, wherein the aluminum plating coating is applied to the inner surface of the end of the steel tube.