Blanking Damping Design And Performance Optimization Simulation Of Punching Hydraulic Press And Its Application

To obtain punching hydraulic presses with high quality and good performance, this thesis provided the technology of blanking damping design and performance optimization simulation of punching hydraulic press. This technology aimed at solving the problems, such as the strong vibration caused by the transient loss of load of sheet metal blanking, structure optimization ignoring bending gaps, lacking blanket simulation and validation on the performance of the press in course of punching and so on. And it had been used in the development of punching hydraulic presses combining with practical project background.The thesis was organized as follows:Chapter 1 reviewed the present research status on blanking vibration reduction of punching hydraulic press, product structure optimization and performance simulation. The problems and shortages are expounded and a technology of blanking damping design and performance optimization simulation of punching hydraulic press was proposed. The main framework and the organizational structure of the thesis were put forward.Chapter 2 proposed a self-adaptive blanking damping design method for transient loss of load of punching hydraulic press host. Before the biggest blanking force during the blanking, the buffer cylinder was pre-compressed. When the sum of the buffer cylinder force and the blanking force equaled the preset value, the pressure of the working cylinder was kept constant. In this way, the buffering force was adaptive with the blanking force during blanking. The influence of the parameters, such as plate thickness and gaps, are investigated on the biggest blanking force and its position. Through LHS (Latin Hypercube Sampling), the approximate function of the biggest blanking force and its position based on response surface modeling was established. At last, the implementation on the buffering method was briefly discussed.Chapter 3 proposed a structural parameters optimization method for fully retightened frame of punching hydraulic press considering bending gaps. The parameterized model between the critical load\mass and the key design size was obtained by analyzing the deformation of the frame under load and calculating the geometric features. The approximate Kriging model of the first-order natural frequency of the frame was also established. A improved Bacteria Foraging Optimization Algorithm (BFOA) was developed to solve the optimization model aiming at maximizing critical load and minimizing the mass with taking the first-order natural frequency and structural size as constraints. This method was verified by taking 20MN sheet metal punching hydraulic press as an example.Chapter 4 proposed a simulation method for analyzing the dynamic and static performance of the hydraulic press in course of punching. The mathematical model about the deformation of critical components under load, contact condition of the upper beam and upright columns, fatigue failure of the cylinder and frame vibration were established by analyzing the course of punching. The dynamic and static performance of the punching hydraulic press was simulated and analyzed comprehensively from the perspective of kinematics, statics, and dynamics. Taking 20MN sheet metal punching hydraulic press as an example, the simulation results of the stiffness, strength of the frame, contact stress of the upper beam and upright columns, fatigue life of the cylinder and 6-order modes of the frame were presented.Chapter 5 developed a product information management and optimization simulation system of the punching hydraulic press combining with practical project requirements. The system was adopted by the enterprise for the management, development and test of punching hydraulic press.Chapter 6 concluded the thesis and summed up the research achievements. The direction of the research on punching hydraulic press in the future was presented.