| When transfer the information, the electric liquid servo system not only use mechanic and hydraulic components, but also use a large number of electric components. Therefore, this electric-mechanic servo system will have a wide outlook for its application in the industry.The present thesis takes specific hydraulic machine-moulding machine as its study target. It designed electric liquid position servo valve system, and takes fluidic mechanic and classical control theory as its base. It set up a math model on the symmetry as its base. It set up a math model on the symmetry valve control the non-symmetry cylinder and adopt rationally PID regulator, this is not only increase the precision of the position control of the system, but also it reduced the performance requirament on other components, except feed back components(such as: zero drilt, dead band etc.). The thesis also raised a simply and practical method of define the open loop raise. This method is based on the major parameter of the soft terrace system. The width of the frequency of the design system reached 751 rad/s. The precision is ±0.02mm. As the thesis designed with a high precision working system. The quality of the oil supply will effect directly on the function for its dynamic property, stability and reliability. For this reason, the thesis choose ration pump-overflow valve which has a good price and excellent performance for its oil supplyer. After found the oil supply model and made the dynamic analysis on it. It express that when it adopted this oil supply system it can fully satisfy the requirement on dynamic function for the electric liquid servo system of the moulding machine.The moulding machine is one of the key equipments on the foundry industry. The result of this study of the thesis will improve the producting lever on the moulding machine manufacture and make our country's the precison control on the moulding machine run into the word's advanced lever. |
