Study On Mechanism Optimization And Force Energy Parameters Of 250 Tons Portal Flying Shear

Flying shear is the key equipment for continuous rolling bar production line.In the production process,the door-type flying shears exist shear blade wear more serious phenomenon,the reason is that the shearing process shear blade speed and mill running speed does not match the phenomenon of pulling and stacking steel and shear blade tilt angle is too large resulting in shear blade tilt cut into the mill.At the same time,due to the poor shear blade structure,the maximum shear force required to shear the rolled parts is large.In order to improve the shearing performance of the flying shear,the flying shear shearing mechanism and shear blade structure need to be optimized.By analyzing the shearing mechanism and working principle of the 250-ton portal flying shear,a mathematical model of the motion of the shearing mechanism was established based on the closed vector method,and the kinematic parameters at the shearing edge were calculated.The results of modeling the shearing mechanism in Adams and performing kinematic analysis are consistent with the mathematical model calculations,indicating that the established mathematical model can accurately calculate the motion parameters of the portal flying shear.To optimize the problem of poor uniformity of shear blade horizontal speed and excessive shear blade inclination in the shearing process of portal flying shears,an optimized mathematical model of the shearing mechanism is established and solved by calling the Fmincon function using the Global Search function.Comparing the motion parameters before optimization,it can be seen that the uniformity of the horizontal speed of the shear blade is improved by 25.1% after optimization;the uniformity of the change of the shear blade inclination is improved by 80.15%.Designing uniform tests on shear blade structure parameters and comparing shear energy changes before and after shear mechanism optimization,and simulating the process of shearing rolled parts in portal flying shears based on the finite element method.From the simulation results of each uniform test group,it can be seen that the optimized shearing mechanism reduces the maximum shear force under the same conditions;from the maximum shear force values of each test group,it can be seen that different shear blade structures have a greater impact on the maximum shear force.In order to reduce the maximum shear force,a fitting function between the maximum shear force and the shear edge structural parameters was established for each test group,and a set of optimized shear edge structural parameters was derived by solving the fitting function.The simulation analysis shows that the optimized shear blade structure reduces the maximum shear force of the sheared rolls.Simulation analysis of the shearing process of 40 Cr and 70 steel rolled parts showed that the maximum shear force was also reduced by using the optimized shear blade structure.