Simulation Research On The Dynamicproperty Of On-Off Cartridge Valve And The Pressuer Descending Property Of Unloading Cartridge Valve

The performance of a hydraulic press depends on its hydraulic system, and the dynamic properties of the main hydraulic elements and key hydraulic circuits are critical to the hydraulic system.In this thesis, the dynamic simulation of main hydraulic units such as two stage, three stage pilot controlled cartridge valve group, three stage unloading cartridge valve group, which are used widely on hydraulic press, is conducted on the software platform of Matlab/simulink.Based on the analysis of methods for mathematic modeling, the mathematic models for each valve group is established following the sequence of their equilibrium equations and continuity equations, the transfer functions or block diagrams resulted from the these mathematic equations. The simulation models are constructed with the Simulink Toolset of Matlab. At last the cartridge valve groups are simulated and investigated with these models.Following above steps, the two stage valve is first studied about its on-off property. Then the common three stage cartridge group is simulated and its response characteristics are examined. Finally the three stage unloading cartridge valve group is researched with simulation to find out the effects of some important parameters. The research works supplies a method and bases for reasonable design of hydraulic system of hydraulic presses and for the future performance prediction.