Research On Magnetorheological Damping Vibration Isolation Of Precision Machine Tools

With the rapid development of manufacturing technology,the precision of precision machine tools has reached micron and sub-micron levels,and higher requirements have been placed on its own working environment.The higher the machining accuracy of the machine tool,the more sensitive it is to the vibration of the surrounding environment,and the greater the damage caused by vibration.Therefore,the harm of isolated vibration to precision machine tools has become one of the key technologies to improve the precision of precision machine tools.The semi-active control technology has the reliability advantages of passive vibration isolation technology,which can achieve the vibration isolation effect of the active vibration isolation technology.The structure of the semi-active control technology is simple and does not require external energy supply,which has become the first choice for the vibration isolation control technology of precision machine tools.Aiming at the vibration isolation characteristics of precision machine tools,a new type of bypass type magnetorheological isolators was designed,and the analysis and testing of the isolators were completed.The main contents and conclusions are as follows:(1)A novel bypass type magnetorheological damper is designed based on the Magnetic Gradient Pinch(MGP).The design and working principle of the magnetorheological damper are described in detail,the magnetic flow field simulation analysis of the damping regulator was carried out by using COMSOL finite element software,the influence of different structural parameters on the pressure drop performance of the damping regulator was also analyzed.The simulation results show that the height of the magnetic conducting ring and the thickness of the magnetic isolation ring have little effect on the magnetic field distribution inside the damping regulator.The height of the magnetic isolation ring not only affects the shape of the magnetic field,but also affects the size of the magnetic field in the vicinity.Under the premise of meeting the design requirements,appropriately reducing the radius of the flow channel can greatly increase the pressure drop range at both ends of the damping regulator,and optimizing the magnetic circuit design based on the simulation results.(2)The characteristics of the existing dynamic model of the MR damper are analyzed.Combined with the neural network algorithm,the intelligent damping model of the MR damper is established,the results of neural network training are basically consistent with the test results.The results show that the neural network modeling method can not only reduce the modeling difficulty of the magnetorheological damper,but also greatly improve the modeling precision of the magnetorheological damper,which lays a foundation for the control algorithm design of vibration isolation system.(3)The dynamic model of the vibration isolation system is established,and the fuzzy controller of the Magnetorheological isolation system is designed.The semi-active control simulation model is built by MATLAB/Simulink,and the vibration isolation system is dynamically simulated under the conditions of harmonic excitation and random excitation signals.The simulation results show that the fuzzy control strategy can greatly reduce the acceleration amplitude of the vibration isolation platform,and its control effect is better than the passive control strategy.(4)A new type of bypass magnetorheological damper based on magnetic gradient pinch mode was fabricated,and a vibration isolation system test platform was built.The vibration isolation performance test of the vibration isolator was carried out by the impact and simple harmonic vibration test method.The results show that the vibration isolation system has a good vibration isolation effect.