Исследование влияния настройки рабочих роликов на качество правки листового металлопроката

Gribkov E. P., Kovalenko A. K., Ivchyk R. S., Titenko O. A. Influence of work rollers settings on the quality of sheet metal straightening. Material working by pressure. 2020. № 1 (50). P. 236-242. One of the main tasks the definition of technological settings leveler is to determine the maximum overlap rolls. In the known works on sheet metal levelling study the roller overlaps are set on the basis of experimental data, which can be used for straightening sheets of material with yield strength up to 1000 MPa, and for materials with higher yield strength requires additional research. The purpose of this work is to establish criteria that affect the maximum allowable overlap of the leveler working rollers and to establish dependencies for the most rational settings of the working rollers. When solving the set tasks, the numerical analytical mathematical model of the straightening process developed by the authors was used as an objective function, which allows one to determine the energy-power parameters and curvature of the sheet after straightening, depending on the individual settings of the levelers rollers. As part of the work, an algorithm of a mathematical model was developed that allows one to determine the leveler technological settings, necessary for correcting the longitudinal curvature and comes down to determining the setting coordinates of each of the movable rollers, depending on the known parameters of the metal being processed, the leveler geometric parameters, as well as the permissible value of the residual curvature of the sheet after straightening. Laws were established for the rational positioning of the rollers as a result of studying the effect of working rollers settings on the quality of sheet metal straightening. Linear and sinusoidal laws were identified as optimal. Boundary factors were also established that affect the maximum roller overlap. These factors included the grip condition and the strength condition of the rollers. Using the example of the implementation of the developed finite element model of the sheet straightening process in relation to the NKMZ leveler, it was found that the grip condition has the dominant influence when straightening sheets with a thickness of less than 6 mm, and the strength condition at large thicknesses. With a decrease in the yield point of the material or the width of the sheets, this ratio will be redistributed towards the capture condition.