| The production of large forgings is an important basic industry of mechanicalmanufacturing, and the manufacturing capability and level of free forging hydraulicpress is the symbol of national strength. Distributor is the key equipment that controlwater flow and switch in hydraulic press. Modern free forging hydraulic press, whosewater way is controlled by oil way, mainly adopts electro-hydraulic servo controlsystem. Based on the existing equipment and conditions, how to improve productivityand the quality of forging is the key problem that needs to be solved for hydraulicpress forging industry.Combining the project of60MN free forging hydraulic press in a company inYanTai, a deep research on the electro-hydraulic position servo control system ofrocker shaft is done and the results as follow:Firstly, the history and research status of hydraulic press and electro hydraulicservo system, the fuzzy control and its application in electro-hydraulic servo systemare summarized in this paper by referring a large number of relevant literatures. Thecomposition of60MN free forging hydraulic press system, structure ofelectro-hydraulic servo system in hydraulic press distributor’s rocker shaft areanalyzed in particular. The mathematical model of60MN free forging hydraulic presselectro-hydraulic proportional system is established.Secondly, considering the nonlinear characteristics such as uncertainty, externaldisturbance, time-varying etc., the parameter self-setting Fuzzy-PID controller for thedistributor rocker shaft’s electro-hydraulic servo system is designed by combiningfuzzy logic control with traditional PID control. Meanwhile, in order to improve theperformance of fast forging, the feedforward compensation, which makes thedistributor rocker shaft has good following performance, is introduced into Fuzzy-PID controller. The system’s control effects under different input signal are validatedthrough a large number of simulation results.Finally, the network structure and the hardware system of control system for the 60MN free forging hydraulic press system are established, and the software programof principal computer and subordinate computer are designed. The feasibility andeffectiveness of the control method is verified by analyzing the operation datacollected during running the equipment. |
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