In 2007, the controversy over the connection of internal and external air conditioners for air-conditioning materials, namely "good copper pipes, and good copper and aluminum pipes," has evolved from an "infighting bucket" to a "battle". The reason why it is called "Infighting" refers to the "copper-aluminum pipe" as early as the 1980s began to use, but has not been the focus of attention, mainly due to the price of copper and aluminum raw materials. The reason why it is called "battle and fight" is that in recent years, since 2004, due to various factors at home and abroad, the price of copper raw materials has risen sharply. In 2004, it was between 20,000 yuan/ton and 30,000 yuan/ton. In 2005, it was between 30,000 yuan/ton and 40,000 yuan/ton, and in early 2006 it was more than 45,000 yuan/ton, and the highest was more than 85,000 yuan/ton in the middle of the year. It is now maintained at about 60,000 yuan/ton. In order to reduce production costs and increase market competitiveness, enterprises began to pay attention to the use of "copper-aluminum pipes" instead of copper pipes. This led to the "copper-aluminum dispute," copper and aluminum tubes are "black heart tube" or new technology, companies, experts say different.
In fact, the "copper-aluminum pipe" is not only used for connecting pipes for air conditioners, but also for refrigerators, air conditioners, condensers and evaporators (commonly referred to as "two devices"). The manufacturing method of the "copper-aluminum pipe" can be divided into welding and non-welding methods, among which the welding method includes friction welding, energy storage welding, flash welding, resistance welding, brazing and ultrasonic welding, and the non-welding method includes a rocker ring and a screw thread. And adhesive pressure and so on. In this paper, the "copper-aluminum tube" welding technology is mainly introduced to the "copper-aluminum tube" technology R & D process, and strive to enable readers to fully understand the "copper and aluminum tube" technology.
Foreign situation
In 1957, the former Soviet Union saw the flash butt welding technology of copper and aluminum tubes, and developed MCKH-150 copper and aluminum flash welding machines, capable of welding copper and aluminum tubes with a diameter of 10mm to 30mm [1].
In 1972, cold pressure welding of copper and aluminum pipes appeared in the former Soviet Union [2].
In 1977, ultrasonic high-temperature welding of copper-aluminum pipes appeared in the United States. Copper-clad aluminum joints were used. The end of the copper pipe was flared and the aluminum pipe was inserted during welding. The welding specifications were 5.75mm and 7.4mm. , Aluminum tube diameter 6mm, 8mm [3].
In 1985, copper-aluminum pipe magnetic pulse welding technology appeared again in the former Soviet Union [4].
In 1988, a high-frequency heating and pressure welding technique for copper-aluminum pipes appeared in Japan. The welding specifications were copper pipe diameter 8mm, wall thickness 1mm, aluminum pipe diameter 8mm, and wall thickness 1.2mm [5].
In 1998, Japan appeared in the form of "aluminum-clad copper" joints, that is, the end of the copper tube was shrunk. When it was welded, it was inserted into an aluminum tube. The welding specification was a copper tube diameter of 8 mm, a wall thickness of 0.6 mm, and an aluminum tube diameter of 8.2 mm. Wall thickness 0.6mm [6].
In addition, in 1975, Japan began to study the thin-walled copper tubes of air-conditioning heat exchangers, and the wall thickness was reduced from 1.0mm, 0.8mm to 0.41mm, or even 0.35mm[7]. The data [7] also mentioned that the United States had used copper tubes with a diameter of 8 mm and a wall thickness of 0.3 to make air-conditioning heat exchangers.
Domestic situation
Basically all use the "aluminum copper" connector form.
In 1984, the explosion welding technology of copper-aluminum connecting pipes for refrigerators was identified by the provincial department [8]. In 1985, Chen Yongfu of the Changsha Research Institute of Mining and Metallurgy published the paper on the explosion welding of copper-aluminum connecting pipes for refrigerators. The specifications are copper tube diameter 8mm, wall thickness 1mm, aluminum tube diameter 8mm, wall thickness 1.5mm [9].
In 1987, Xie Jian et al. of the Chengdu Electric Welder Research Institute published a research paper on the friction welding of copper-aluminum pipes. The specifications of the copper-aluminum pipes are all 8 mm in diameter and 1.5 mm in wall thickness [10].
In 1988, Zhang Dejun, a senior engineer of Beijing Shipping Integrated Technology Development Corporation, successfully developed the Yu-0288 aluminum-copper semi-automatic special flash welding machine, which can produce 600,000 copper-aluminum pipe joints annually with a pass rate of over 98%[11].
In 1989, Guo Shunxiang of Xinxiang Refrigerator Factory also introduced the flash welding technology of copper and aluminum pipe joints for evaporators. The welding machine is an Italian-made T8/P copper-aluminum pipe welder. The welding capacity is 25kVA, and the copper and aluminum pipe specifications are all diameters. 8mm, wall thickness 1mm [12].
In 1991, Li Peisen of Xi'an Aero Engine Company announced the energy storage welding of copper-aluminum joints for refrigerators, and successfully developed the PW-1 type energy storage welder. The specifications of copper and aluminum pipes are all 8 mm in diameter and 1 mm in wall thickness[13] .
In 1994, Zhu Yanping and others from Shanghai Jiaotong University published research papers on DC-flash welding of copper-aluminum pipe joints for refrigerators. The specifications of copper and aluminum pipes are 8mm in diameter and 0.8mm in wall thickness [14].
In 1998, Zhang Xichuan of Shenyang University of Technology published a research paper on resistance welding of copper-aluminum pipes and developed a microcomputer-controlled plug-in copper-aluminum pipe resistance welding machine. The time control precision of this machine is 0.01s and the daily production capacity is 200. The passing rate of more than 98% [15].
In the same year, Xu Daorong of Hefei University of Technology published a copper and aluminum tube for refrigerators.
In fact, the "copper-aluminum pipe" is not only used for connecting pipes for air conditioners, but also for refrigerators, air conditioners, condensers and evaporators (commonly referred to as "two devices"). The manufacturing method of the "copper-aluminum pipe" can be divided into welding and non-welding methods, among which the welding method includes friction welding, energy storage welding, flash welding, resistance welding, brazing and ultrasonic welding, and the non-welding method includes a rocker ring and a screw thread. And adhesive pressure and so on. In this paper, the "copper-aluminum tube" welding technology is mainly introduced to the "copper-aluminum tube" technology R & D process, and strive to enable readers to fully understand the "copper and aluminum tube" technology.
Foreign situation
In 1957, the former Soviet Union saw the flash butt welding technology of copper and aluminum tubes, and developed MCKH-150 copper and aluminum flash welding machines, capable of welding copper and aluminum tubes with a diameter of 10mm to 30mm [1].
In 1972, cold pressure welding of copper and aluminum pipes appeared in the former Soviet Union [2].
In 1977, ultrasonic high-temperature welding of copper-aluminum pipes appeared in the United States. Copper-clad aluminum joints were used. The end of the copper pipe was flared and the aluminum pipe was inserted during welding. The welding specifications were 5.75mm and 7.4mm. , Aluminum tube diameter 6mm, 8mm [3].
In 1985, copper-aluminum pipe magnetic pulse welding technology appeared again in the former Soviet Union [4].
In 1988, a high-frequency heating and pressure welding technique for copper-aluminum pipes appeared in Japan. The welding specifications were copper pipe diameter 8mm, wall thickness 1mm, aluminum pipe diameter 8mm, and wall thickness 1.2mm [5].
In 1998, Japan appeared in the form of "aluminum-clad copper" joints, that is, the end of the copper tube was shrunk. When it was welded, it was inserted into an aluminum tube. The welding specification was a copper tube diameter of 8 mm, a wall thickness of 0.6 mm, and an aluminum tube diameter of 8.2 mm. Wall thickness 0.6mm [6].
In addition, in 1975, Japan began to study the thin-walled copper tubes of air-conditioning heat exchangers, and the wall thickness was reduced from 1.0mm, 0.8mm to 0.41mm, or even 0.35mm[7]. The data [7] also mentioned that the United States had used copper tubes with a diameter of 8 mm and a wall thickness of 0.3 to make air-conditioning heat exchangers.
Domestic situation
Basically all use the "aluminum copper" connector form.
In 1984, the explosion welding technology of copper-aluminum connecting pipes for refrigerators was identified by the provincial department [8]. In 1985, Chen Yongfu of the Changsha Research Institute of Mining and Metallurgy published the paper on the explosion welding of copper-aluminum connecting pipes for refrigerators. The specifications are copper tube diameter 8mm, wall thickness 1mm, aluminum tube diameter 8mm, wall thickness 1.5mm [9].
In 1987, Xie Jian et al. of the Chengdu Electric Welder Research Institute published a research paper on the friction welding of copper-aluminum pipes. The specifications of the copper-aluminum pipes are all 8 mm in diameter and 1.5 mm in wall thickness [10].
In 1988, Zhang Dejun, a senior engineer of Beijing Shipping Integrated Technology Development Corporation, successfully developed the Yu-0288 aluminum-copper semi-automatic special flash welding machine, which can produce 600,000 copper-aluminum pipe joints annually with a pass rate of over 98%[11].
In 1989, Guo Shunxiang of Xinxiang Refrigerator Factory also introduced the flash welding technology of copper and aluminum pipe joints for evaporators. The welding machine is an Italian-made T8/P copper-aluminum pipe welder. The welding capacity is 25kVA, and the copper and aluminum pipe specifications are all diameters. 8mm, wall thickness 1mm [12].
In 1991, Li Peisen of Xi'an Aero Engine Company announced the energy storage welding of copper-aluminum joints for refrigerators, and successfully developed the PW-1 type energy storage welder. The specifications of copper and aluminum pipes are all 8 mm in diameter and 1 mm in wall thickness[13] .
In 1994, Zhu Yanping and others from Shanghai Jiaotong University published research papers on DC-flash welding of copper-aluminum pipe joints for refrigerators. The specifications of copper and aluminum pipes are 8mm in diameter and 0.8mm in wall thickness [14].
In 1998, Zhang Xichuan of Shenyang University of Technology published a research paper on resistance welding of copper-aluminum pipes and developed a microcomputer-controlled plug-in copper-aluminum pipe resistance welding machine. The time control precision of this machine is 0.01s and the daily production capacity is 200. The passing rate of more than 98% [15].
In the same year, Xu Daorong of Hefei University of Technology published a copper and aluminum tube for refrigerators.
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