The Researches On The Moving-coil Servo Valve Based On High Magnetic Strength Permanent Magnetism Material

Electro-hydraulic servo system has strong output power and high control precision character, widely used in various produce fields. Electro-hydraulic servo valve as the key component of the electro-hydraulic servo control system, the function of electro-hydraulic servo valve will influence whole electro hydraulic system's performance. With the industry developing, bring forward higher requirement to electro-hydraulic servo valve, such as quicker response speed, larger frequency width, better stability in working state, and realizing its digitization and intellectuality. The article's research purpose is improving electro-hydraulic servo valve function.Neodymium iron boron (NdFeB) permanent magnetism material with high magnetic strength, has larger remanence and coercive force, as well as bigger magnetic energy product, especially has higher intrinsic coercive force. If it is used in the moving-coil strength motor, the performances of the moving-coil strength motor will be greatly improved. The paper is on extensive research domestic and international relevant documents, materials and foundation of working, based on Th-7/10 type servo valve, improving dynamic characteristics such as the frequency width, response speed of the servo valve of the electric liquid, etc. as the guiding ideology, makes design researches on each part of the servo valve.During the design of the moving-coil strength motor in the machine - electric coupling part, select the neodymium iron boron permanent magnetism material with excellent magnetic performances as the permanent magnet of magnetic steel, construct the structure and damping coupling models of the moving-coil strength motor re founded based on the analyzing and study on the structure, strength, magnetic flux distribution, then carry on magnetic circuit analysis and structural design to both interior and exterior magnetism types separately. The result is that the natural frequency and thrust of strength motor are improved, together with smaller volume, quicker response speed, less weight of the motor, quicker response, sensitivity improvement, weight is lightened. On this basis, apply it to the design of the electro-hydraulic servo valve, with data provided give out structures and parameters calculation of other parts of the servo valve.Use the power bond graph theory to build up the power bond graph model, deduce the equations of states, and make the artificial analysis in both time and frequency domains with the artificial software MATLAB/ SIMULINK. From the graphs, we can see the servo valve based on NdFeB permanent magnetism material has better dynamic performances compared with Th-7/10 type servo valve.In order to realize digitization and intellectuality of the servo valve based on NdFeB permanent magnetism, the digital servo controller has been developed, which realizes transmission and communication of the digitized signals of the servo valve through Profibus on-the-spot bus technology and industrial Ethernet. Using Visual C++ 6.0 language combined...