Development of a closed-loop moving-coil fluid power proportional valve with LVDT

• Main Authors: Shih-cyuan Li, 李世筌
• Other Authors: Jyh-Chyang Renn
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/99370689806952949458

碩士 === 國立雲林科技大學 === 機械工程系碩士班 === 95 === Nowadays, the electro-mechanical actuator for hydraulic and pneumatic proportional valve is almost the proportional solenoid. Generally speaking, disadvantages of the proportional solenoid are slow response and expensive. This research discusses the replacement of the proportional solenoid with moving-coil actuator, to develop a new type hydraulic and pneumatic proportional valve. Because the moving-coil actuator has the advantages of faster response and constant output force, it shows large potential of the application to the pneumatic control valves. In this study, the software Labview is utilized to develop the control system. The 10μm accuracy of position control using PID feedback controller is reachable. It is expected that the new developed proportional valve with moving-coil actuator is able to replace the traditional servo valve or proportional valve in the future. The structure of the moving-coil actuator in the thesis includes hollow coil, permanent magnet and yoke. Once the coil is energized, the hollow coil pushes the spool of the proportional valve to move and reach a definite position by combining with LVDT to achieve closed-loop control. Methods of analysis and design discussed in this thesis are Fleming left-hand rule, finite element method (FEM) and building and constructing block diagram of control system using MATLAB-Simulink software. Finally, experimental results prove that the moving-coil proportional valve has the signification advantage of faster response.