The Study On Passive Synchronous Balancing System Of800MN Die Forging Hydraulic Press

With the rapid development of aerospace, large vessels, energy and other industries,the demands for large die forging workpieces are grown day by day, such as aluminumalloy, magnesium alloy, titanium alloy, etc. At present, most of these products need to beimported.800MN die forging hydraulic press is as a key equipment for the productionof these products, it will play an important role in these industries. Large die forgingpress is a complex system included machinery, electric and hydraulic systems, theseprocesses will be faced unprecedented challenges, such as design, manufacture andassembly. Among them, the processing precision of these products are directly affectedby the hydraulic synchronous control system.There are two hydraulic synchronous control technologies as follows: activesynchronous balancing system; passive synchronous balancing system. In this paper, thepassive synchronous balancing system of800MN die forging press is studied, thereasons why the die forging press is not synchronized are analyzed and classified, whichis based on the theory of hydraulic press design, manufacture and assembly, as well asthe characteristics of the working process. Diagonal balancing principle is widelyapplied to forging press, according to this principle, the load characteristics of thewalking beam are analyzed, the force and torque equilibrium equations are listed, theoutputs of main working cylinders’ force are corrected according to these equations. Thespatial position of walking beam is analyzed, the adjustment strategies of walking beamare determined by the analysis results.According to the basic design principle of hydraulic press’ hydraulic system, themain parameters of passive synchronous balancing system are calculated anddetermined. By analyzing the working principle and control information flow of passivesynchronous balancing system, the mathematical model is deduced withelectro-hydraulic servo valve controls symmetrical hydraulic cylinder, theelectro-hydraulic position servo system transfer function is established, and the system’sstability is analyzed.According to the PID control principle and the adjustment strategy of walking beam,the hydraulic simulation model of Easy5software is established, the responseperformance of walking beam is analyzed on the condition that the walking beam isundertaken the main cylinders’ load or not. Meanwhile, the optimization of the system is proposed according to the simulation results. Finally, the walking beam’shigh-precision control of the die forging press is realized.