Surface Finish Defect Of Roll Grinding Based On Multi-Source Error Research On Creation Modeling

Roll grinder is the core equipment in plate processing.Affected by high temperature and pressure during rolling,the surface of roll is prone to wear and surface quality is reduced.Roll grinder can grind and repair the surface of roll.Influenced by various errors,such as geometric error,mechanical error,thermal error,control system error,load error,etc.,various surface quality defects will also occur during roll grinding.Vibration defects are complex in origin,difficult to quantify and easy to be eliminated,which easily transmits to the surface of plate and affects the processing quality.In order to solve this problem,according to the material removal process of roll grinding,the formation mechanism and influencing factors of vibration are analyzed,quality indexes are formulated,surface defect simulation model of coupling geometric error and forced vibration is established,which provides guidance for subsequent research and solution.The main contents of this paper are as follows:First,surface quality defects in roll grinding are classified and surface texture defects such as vibration are classified as process surface quality defects.By monitoring the amount of roll grinding process,it is found that the driving current and speed of grinding wheel fluctuate at the same frequency when vibration occurs and decrease,so it is analyzed that the formation of vibration is caused by impact of grinding wheel.The retrospective study on impact shows that there are installation errors in the roll and the roll is prone to runout when turning.Combining grinding chatter and forced vibration,it can be seen that the unstable rotation of rolls has an impact on the grinding wheel,resulting in changes in the load and speed of the grinding wheel and the appearance of grinding texture different from that of other parts.Based on the above analysis,the factors influencing the formation of texture defects on the roll surface are the geometric errors of the grinder and the passively changed rotating state of the grinding wheel.On this basis,a model of surface texture defects in roll grinding facing multi-source error is established,which is convenient for studying the mechanism of influencing factors.Based on the analysis of the formation mechanism of surface texture defects,the roll installation error is the final reflection of grinder structure error and assembly error on the roll installation according to its motion transfer relationship.The roll installation error is traced back and its mechanism of action on surface texture defects is studied.The special processing mode of the roll grinder,i.e.double-rotation machining,is analyzed.Based on the theory of multi-body system,the position-attitude relationship between adjacent bodies is analyzed,and the geometric error model of the roll grinder is established according to its low-order body array and topological structure.According to the material removal method of the roll,the grinding surface with only geometric error is simulated by incorporating geometric error into surface texture to create a model.Aiming at the material removal easily changing during grinding,the elastic deformation and equivalent stiffness are defined,the material removal model based on grinding power and the dynamic model of grinding wheel roll are established,the change of equivalent stiffness of grinding wheel and roll during grinding is analyzed,and the time delay between grinding wheel rotation and roll is studied.Finally,coupling the change of grinding wheel rotation delay and roll geometry error,incorporating the surface texture defect of roll grinding to create a model,analyzing the effect of surface texture defect formation under different process parameters,and carrying out experimental verification.It lays a foundation for subsequent research on suppression and elimination of surface texture defects.