Double-layer winding-soldering pipe production technology for connection of indoor/outdoor unit of air conditioner

Abstract

The present invention provides a production process of double wall brazed tube for connecting air-condition indoor and outdoor machine, putting a horizontally striping double-sided copperplating steel belt made from low-carbon gapless atomic steel on a uncoiling disk; coil rolling the copperplating steel belt at 720 degrees on forming machine to form double wall brazed tube canister; entering brazing furnace, and injecting decomposed protection gas NH3 in the furnace to solder; entering the double wall brazed tube after soldering to sealing cooling tube filled with decomposed protection gas NH3 to cool, and cooling slowly and cooling again; spraying and drying directly by passivation water; collecting to disk shape by winder and the disk shaped double wall brazed tube is obtained. The disk shaped double wall brazed tube is processed by off-line controllable atmosphere bright annealing and fixed length. The double wall brazed tube obtained by present invention has plastic strain ratio r >2.0, strain hardening index n >0.25, elongation delta >45%, yield strength delta s <150 Mp; when installing as air-condition connecting pipe, can realize manual molding in installing scene of air-condition connecting pipe, can't appear staved and cockled phenomenon of the tube wall, and reduces partial energy consume at the same time.

Description

technical field [0001] The invention belongs to the field of manufacturing engineering, and in particular relates to a production process of a double-layer rolled welded pipe used for connecting indoor / outdoor units of an air conditioner. Background technique [0002] Double-layer coiled welded pipe is a kind of small-diameter thin-walled double-layer straight seam formed by cold-rolled strip steel with double-sided copper plating, rolled at 720° on a special forming unit to form a double-layer coiled welded pipe tube, and then brazed at high temperature. Precision steel pipe. The pipe has the characteristics of high pressure resistance, corrosion resistance, high vibration fatigue resistance, smooth inner surface and low price. It is an ideal pipe to replace copper pipes. It has been produced in my country for nearly 20 years. It was mainly used in refrigerators and freezers in the early stage. Condenser pipes (now gradually replaced by single-layer welded pipes) are curren...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problem that the existing double-layer coiled welded pipe cannot replace the copper pipe connected to the indoor / outdoor unit of the air conditioner, and provides a lower yield strength, which is more convenient for manual bending and forming, and has good drawing and forming performance. There will be no flattening or wrinkling of the pipe wall, and it is more suitable for the production process of double-layer welded pipes for the connection of indoor / outdoor air conditioners in industrialized mass production.

Images