In order to investigate the effects of multiple coupling parameters on multi-cylinder hydraulic parallel drive system,a dynamic mathematic model of drive system for hydraulic press was established based on analytic methodology.The influences of system parameters of viscous damping coefficient,elastic modulus,mass of moving beam,and load stiffness on dynamic behaviors of hydraulic drive system were studied using variable step length Runge-Kutta method.Results showed that the magnitude of transient oscillation is diminished by increasing viscous damping coefficient or decreasing mass of moving beam.System dynamic response can be accelerated provided that the elastic modulus is increased or the pipe diameter is decreased.The pressure of major cylinder and system steady-state error rise with the increase of load stiffness. Furthermore,active synchronization control is not recommended when the machine is in fast approaching period.The stability of the system must be emphasized if the hydraulic press is driven under on-load or the forged piece is in plastic deformation stage,while tracking accuracy is a key issue when the workpiece is under elastic stage.The research results could provide theoretical basis for the design of system and parameter selection.
