The Research On The Shape Control Of High Precision Copper Strip

Copper and copper alloy are two important basic materials in modern industry.With the development of science and technology, there comes increasingly demand for elaboration of products and precise copper strip in the fields of instrument, electric and electronics. Meanwhile, copper strip products are required to have high precision and surface quality. Currently a lot of copper strips need to be imported every year to meet our domestic demand. What’s more, the product prices are more than 15% higher than that of the same level product as a result of international oligarch controlling the market, forming the situation that our copper strip production is badly disciplined by others. Plate, sheet and strip products are mainly made by rolling mills. At present,domestic scholars’ researches on strip rolling are focused on steel sheet rolling, while cold rolling of copper strips are different from steel sheet rolling no matter in rolling force calculation, selection of rolling mill technological parameter or strip shape control technology. Consequently, researches on the shape control technology of high-precision copper strips appears to be particularly important.In this paper, the author first introduces the basic concept and relevant knowledge of strip shape and then goes into the strip shape theory. Use influence function method to establish the basic model of four-high mill’s roll elastic deformation, then deduce the function of the elastic bending of work and backup rolls, and work rolls’ bending forces, flattening between rolls, work roll flattening caused by rolling forces. And the force balance equation of roll system’s elastic deformation, the equation of force and displacement and the deformation compatibility equation are obtained. Adopting Rolling force model which is suitable for cold rolled copper belt, its coefficient of friction model and deformation resistance model makes the roll elastic deformation model are more suitable for practical production. Discipline diagrams are used for analyzing the disturbance factors’ influence on strip shape, including rolling force,strip convexity, thermal crown, strip width, tension and roll bending force. The author also explains how elastic deflection of roll, flattening between roll, between work roll and rolled piece affect the strip thickness distribution. On the basis of elastic deformation of rolls established by influence function method, influences of rolling force, roll bending force and diameters of roller on the load bearing of the roll gap deformation convexity are analyzed, as well as the influences they have on the secondand the fourth roll gap deformation convexity. Moreover, the different impact that different strip widths and roller diameters have on the roll gap deformation convexity of rolling force and roll bending force.The research of this paper can guide the practical production of copper strip.