| The traditional product is produced in steel industry for China and has a huge overcapacity problem. But the high-quality plate produced critically for high-end equipment and defence industries are in short supply. Its production equipment relies on imports, so steel industry transformation development is controlled by others. The rolling shear mechanism is one of the three key equipments, but the rolling shear equipment imported is complexity and bulkiness. Especially for plates that are both wide and thick, the shearing technology seriously restricting the development of the steel industry in transition.New hydraulic bilateral rolling shear is composite connecting rod shearing mechanism with the upper blade driven by servo-cylinders. The pure rolling shear of steel plate is implemented, and the problem of relative sliding between plate surface and shear blade during the shearing is resolved, which lead to the plate shear quality is improved. Some characteristics stick out for the bilateral rolling shear: structure is simple, shear force is powerful, and shear steel section is of high quality and so on. However, the hydraulic bilateral rolling shear shearing mechanism with multiple degrees of freedom is mutual coupling. Hydraulic cylinder is the power source of the shearing mechanism, of which performance will directly affect the control system accuracy and dynamic and static quality.Taking ShaoXing Steel Co. shearing institutions as a research object. According to the theory of kinematics and dynamics of planar composite link mechanism, state equation between hydraulic cylinder displacement and the pose of upper blade is developed. The Krasovskii's method is adopted for the stability analyses of bilateral rolling shear, which show that the shearing mechanism is stable and reliable. In this paper, mathematical model of the hydraulic system is obtained by using the method of asymmetric valve control asymmetric cylinder, nonlinear state equations of hydraulic cylinder pressure and flow rate is obtained. Stability of four cylinders coupling nonlinear system is analyzed by using Liapunov's stability criterion. Since the output of the hydraulic cylinders on both sides of the hydraulic shearing agencies are simultaneously on the upper blade. Each output of the system will be affected by external interference factors. Control system decoupling device is designed by using differential geometry, and preparation of simulation program is written. Simulation results show that hydraulic system of multi-degree of freedom nonlinear systems is stable and decoupling. By acquiring the experimental data show that the four-cylinder trajectory can better follow the established trajectory and this method can meet the actual needs of the scene, which verify the rationality of the theoretical derivation and the feasibility of the control method.In order to analyze the reliability and stability of the system, the mathematical model of the hydraulic bilateral rolling shear mechanism is established and its stability is analyzed in this paper, simulation and experimental results validate the theoretical derivation. The results showed that the upper blade can follow the ideal trajectory, which meet the shearing quality of steel plate and pave the way for dynamics analysis of hydraulic bilateral shear mechanism. |
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