The air conditioner indoor and outdoor machine double-layer winding-soldering pipe production technology for connection of indoor
Technical field
The invention belongs to the manufacturing engineering field, be specifically related to a kind of air conditioner indoor and outdoor machine double-layer winding-soldering pipe production technology for connection of indoor.
Background technology
Double coiled welded tube is to use cold-strip steel after two-sided copper facing, and volume rolls 720 ° of formation double coiled welded tube sockets on the special molding unit, the more double-deck vertical masonry joint precision tube of a kind of small-bore thin-walled that forms through high temperature brazing.That this tubing has is high pressure resistant, corrosion-resistant, antivibration fatigue strength height, inner surface is bright and clean and characteristics such as low price, be the desirable tubing that substitutes copper pipe, produced recent two decades in China, be mainly used in the condenser tube (being replaced by the individual layer welded tube gradually now) of refrigerator, refrigerator-freezer early stage, be mainly used at present and make vehicle brake pipe and various oil pipe, very ripe in these application technology.
By industry standard YB/TO69 regulation, at present, the double coiled welded tube industry production is 0.02~0.08% with the material carbon content.And in double coiled welded tube research is for many years made and is used, people pay close attention to the application of auto industry always, improve withstand voltage, the intensity and the reliability of double coiled welded tube, even research and develop three layers, four layers volume welded tube forming technology (seeing document " mechanical engineering and the automation " fifth phase in October, 2005).Existing double coiled welded tube yield strength δ s is generally 200~260Mpa, and percentage elongation δ is generally 25%~32%.Though withstand voltage and antivibration fatigue strength height has reduced its mouldability, therefore, must be during moulding by bending machine or mould, people only use the strength of hand can't moulding; Simultaneously, big caliber flattens in the brake forming process easily, and tube wall is wrinkling, sometimes will be by wrinkle resistant plate.Just since above drawbacks limit the application of double coiled welded tube.As the air conditioner indoor and outdoor machine tube connector, need offhand at the scene during installation, existing double coiled welded tube can't use, and still uses copper tube so far.China's copper natural resources shortage, price is higher, and the price of double coiled welded tube is about 30% of a copper tube.Simultaneously, the strength ratio double coiled welded tube of copper tube is much lower, yielding, is used for the air conditioner indoor and outdoor machine tube connector, in installation process, require installation personnel can not produce because of the excessive damage horn mouth of exerting oneself and leak because of the firmly not enough stubborn leakage that tightly do not produce; Even install, in use meet by chance and collide with, also be easy to generate leakage.Use double coiled welded tube instead, and adopt double-deck enlarging connected mode, can fundamentally stop connector and leak.In addition, the thermal conductivity of copper is 384w/ (m a ℃), and the thermal conductivity of steel is 47w/ (m a ℃).The thermal conductivity of copper is the octuple of steel, and it is 1m that wall thickness is worked as in expression, and when the temperature difference was 1 ℃, at the heat (J) that the unit interval (s) passed by unit are (m2), copper was the octuple of steel.Though increased muff during use, to reduce thermal loss, under equal conditions thermal loss is higher than double coiled welded tube certainly.So air conditioner connecting pipe adopts double coiled welded tube, can reduce thermal loss to a certain extent, plays energy-saving and cost-reducing effect.
Summary of the invention
The objective of the invention is to solve existing double coiled welded tube and can't replace the problem that air conditioning chamber's inside/outside machine connects copper tube, provide a kind of yield strength low, be convenient to artificial bending forming, have good drawing and forming performance, can not occur during shaping flattening, the air conditioner indoor and outdoor machine double-layer winding-soldering pipe production technology for connection of indoor of tube wall wrinkling.
For achieving the above object, the technical solution used in the present invention is: uncoiling: at first with W (C)<0.008%, the two-sided copper facing steel band of the itemize that the Ultra-low carbon gapless atomic steel of W (N)<0.003% is made lies against on the uncoiling dish; Moulding: the copper facing steel band rolled up on make-up machine roll 720 ° and form the double coiled welded tube sockets; Soldering: the double coiled welded tube socket of forming is sent in the soldering oven continuously, and in stove, fed NH
3Decomposing protection gas is that solder carries out soldering at 1084 ℃ with copper; Annealing: the double coiled welded tube that soldering is good send into length be 10~15 meters add insulation, interior logical NH
3In the box annealing stove of decomposing protection gas,, annealed 30~50 seconds, realize the overaging annealing of double coiled welded tube at 830 ℃~900 ℃; Cooling: logical NH in the double coiled welded tube after will annealing is sent into continuously
3Decomposing protection gas adds in the closed stainless steel pipe of recirculated water cooling cover and evenly cools off; Passivation spray: cooled double coiled welded tube is sent in the spray section, directly sprayed, make the volume surface of welded pipe form one deck passivation protection film with passivation water; Flaw detection: passivation sprays cooled double coiled welded tube and passes eddy current flaw detec, and volume welded tube welding quality is carried out flaw detection; Rolling: the double coiled welded tube after will detecting a flaw is gathered into plate-like with winder and gets final product.
Double coiled welded tube according to production technology of the present invention makes is characterized in that: its plastic strain ratio r〉2.0, strain hardening exponent n 0.25, percentage elongation δ 45%, yield strength δ s<180Mpa.
The double coiled welded tube plastic strain ratio r that adopts production technology of the present invention to obtain〉2.0, strain hardening exponent n 0.25, percentage elongation δ 45%, yield strength δ s is less than 180MPa.Strain hardening exponent n value is high, distortional stress increases sharply with strain, help realizing homogeneous deformation, simultaneously, have very high plastic strain ratio r again, have good drawing and forming performance, when installing as air conditioner connecting pipe is on-the-spot, can realize the artificial shaping of air conditioner connecting pipe erecting bed, flattening, tube wall wrinkling can not occur, air conditioner connecting pipe uses double coiled welded tube also can reduce the part energy consumption simultaneously.
Description of drawings
Fig. 1 is production equipment figure of the present invention.
The specific embodiment
Below in conjunction with accompanying drawing the present invention is described in further detail.
The present invention produces double coiled welded tube copper facing steel band and selects Ultra-low carbon gapless atomic steel [W (C)<0.005% for use, the accurate cold-rolled strip of W (N)<0.003%, steel band carries out two-sided copper facing earlier, copper facing thickness is 0.003~0.004 millimeter, according to the caliber size, the width that the sub-cut of copper facing steel band is become to require lies against copper facing itemize steel band on the uncoiling dish 1 again; Itemize steel band head and last steel band afterbody welding; The copper facing steel band rolled up on make-up machine 2 roll 720 ° and form the double coiled welded tube sockets; Open NH
3Decomposing protection gas pipeline valve will be full of NH in soldering oven 3, annealing furnace 4, the cooling tube 5
3Decomposing protection gas; Start production line, it is that solder carries out soldering with copper that soldering oven 3 temperature are transferred to 1084 ℃, the double coiled welded tube that soldering is good send into length be 10~15 meters add insulation, interior logical NH
3In the box annealing stove 4 of decomposing protection gas,, annealed 30~50 seconds, realize the overaging annealing of double coiled welded tube at 830 ℃~900 ℃; Double coiled welded tube after the annealing is sent into interior logical NH continuously
3Decomposing protection gas adds in the closed stainless steel pipe 5 of recirculated water cooling cover and evenly cools off; Cooled double coiled welded tube is continued to be fed in the spray section 6, directly spray, make the volume surface of welded pipe form one deck passivation protection film with passivation water; Passivation sprays cooled double coiled welded tube and passes eddy current flaw detec 7, and volume welded tube welding quality is carried out flaw detection; Double coiled welded tube after the flaw detection is gathered into winder 8 plate-like obtains having very high plastic strain ratio, very high strain hardening exponent and high percentage elongation δ (δ〉45%), yield strength is low, the double coiled welded tube of good moldability.