| As the development of China's national economy, tubes are being used more andmore widely in various productions. The straightening technology plays a decisive role inhigh-quality production of tubes. As more and more producing and using of precisiontubes, the requirements of the technology and equipments for straightening are increasingquickly. Two-cross-roller straightening machine gets more attention for its features ofstraightening head or trail and high accuracy in the production of tubes; what's more,there is some polishing function of two-cross-roller straightening machine, which canhelp to improve the quality of the tube surface. A lot of studies are being done byprevious for the function of straightening about the two-cross-roller straighteningmachine, but fewer for the function of polishing.During studies of the straightening and polishing of tubes, related theories areinvolved in mechanics of materials, FEM method, the straightening theory andelastic-plastic theory, etc.Based on the principle of two-cross-roller straightening, this issue made acomparative analysis about several main methods that be used to design the profile ofroller curve firstly, after that this issue designed the straightening section oftwo-cross-roller straightening and polishing machine's concave roller which is aimed tothe Φ100mm~Φ150mm thick-walled tube by using the method based on curvature;Established a mathematical model about the principle of two-cross-roller polishing, thisissue improved the profile of the concave roller curve by reference the previous. What'smore, the length of the polishing section has been calculated.While by using the technique of FEM, this issue made a FEM analysis about theprocess of tube straightening and polishing which based on ABAQUS. After extracted thestress, strain and other parameters of the process, this issue analyzed their variation anddistribution, calculated and compared the force and torque of the upper and lower rollers,improved the polishing quality of the tube surface effectively; processed athree-dimensional concave roller model by using the software Solidworks, comparedseveral roller curves. Based on the contact line of tube and roller, finally this issue optimized the α whenstraightening tubes whose diameters are different. The α is the angle between the axis oftube and roller. This optimization gives certain reference for the actual production, whichcan help to avoid the blindness of adjustment. |
