The Research On Hydraulic System Of Two-roll Straightening Machine

Oblique roller straightening machine is a kind of very important equipment in Steel-Pipe production industry, In the process of the pressure processing of the steel, due to affected by many factors in the process of rolling, cooling, transport or heat treatment, Rolled piece will produce bending, thus it will affect the quality of products. In order to eliminate these bend defects, Rolled piece need be straighten by straightening machine, and hydraulic control system is the core of the straightening machine, therefore, this paper will design and research hydraulic system of straightening machine.Through the research on straightening principle, have made control principle program on hydraulic system of straightening machine, and carried out selection calculation based on it, thus have made a complete system design program.This design program focus on fast open-circuit design, this machine is equipped with the two straightening rollers above and below, in two the one above is active roller,and the one below is fixed roller. The roller above carry out press work by two hydraulic cylinders simultaneously, the rollers above and below are rotated by two motor driven. The Front-end of straightening rollers are equipped with photoelectric switch to sensor in time whether there is any bar or bar threaded passing it, when the bar is transmitted to the entrance of the whole machine by the transmission line, the hydraulic power will drive the roller above to Start quickly, after the bar or bar threaded passing the straightening roller,the roller above and below clamp at the same time in order to achieve the purpose of straightening.Through the establishment of mathematical model on the system to observe its dynamic performance, and used MATLAB/Simulink software to create computer simulation model of control system, and then discussed the synchronization control strategy between the hydraulic cylinder, and finally through the conventional PID control strategy carried out simulation of the system to improve the control effect valve-controlled Non-symmetric system of hydraulic cylinder. The results of simulation showed that valve-controlled non-symmetrical hydraulic cylinder can get good stability and self-adaptability, improved the control effect of the system, meet the requirements of practical applications.