Design of continuous variable curvature roll shape and straightening process research for two-roll straightener of bar

Abstract

At present, high straightness precision and good bar surface quality are difficult to meet at the same time in the straightening process of bar. In view of this problem, this paper puts forward a continuous variable curvature roll shape design method, and studies the straightening process setting method. The roll shape of the straightening roll is tangentially connected by multiple segments arc of uniform curvature changes, and the curvature decreases uniformly from the middle to both ends. The roll shape designed by this method can be in good contact with the bar and can effectively improve the surface quality of the straightened bar. In order to make the straightening process parameters more reasonable and effective, reduce the dependence of the production line on workers, and realize the full automatic straightening of the bar, a complete process straightening bending springback model of bar was established. Based on roll shape and bar specification, the optimization iteration model of upper and lower straightening roll angle is established. Then the setting method of the roll gap and the guide plate spacing is discussed. The field straightening process is simulated by finite element analysis. The process setting model is verified on the straightener after roll shape modification. The automatic control of two-roll straightening of bar can be effectively realized by using the roll shape and process model. The straightened bar has high straightness and surface quality.