Very Large Cnc Marine Bending Machine Roller Deflection Analysis And Compensation Techniques

With the rapid development of China's shipbuilding industry, large marine bending machine is one of the important directions of the development of bending machine. Large span upper roller deflection compensation is one of the key technical problems in the development of large marine bending machine. The upper roller plays a vital role in bending process, but its deformation results in uneven pressure distribution in bending process, and reduces the accuracy of sheet metal. This paper studies on a certain 21m large marine bending machine. With theoretical analysis and finite element method, deflection character of upper roller is achieved. Active-compensation to improve deflection of upper roller is bringing forward, and its compensation effect is simulated.Firstly, the mechanical parameters of the bending process of large marine bending machine are obtained. The simulative results and the theoretical calculation are compared, and the normal contact pressure between the upper roller and sheet metal in the bending process is obtained. Secondly, the deflection of the upper roller caused by deadweight and working load is investigated, by taking the theoretical numerical optimization and FEA optimization based on ANSYS, the amount, locations and the imposed loads of bearing rollers are optimized reasonably, which provide a scheme and theoretical basis for reducing the deflection of upper roller and deflection compensation. Thirdly, the method of multi-point support on the upper roller is taken for pre-compensation. There are many groups of bearing rollers and their distribution is according to the optimized results. The results of pre-compensation are obtained through finite element analysis methodology. In order to meet the requirements of sheet metal, before bending according to the simulation results, the bearing rollers' high degree are pre-compensated through electro-hydraulic push rods. Finally, through sensors real-time detect deflection compensation error. To achieve multi-point, independent, automatically and quickly compensate and improve the accuracy of the sheet metal and the rolling efficiency, computer-controlled servo motors and electro-hydraulic push rods adjust oblique irons. The results indicate the study can improve the quality of bending, which can direct improved design to upper roller structure, and active-compensation can supply a new method to engineering applications.