Research On Vibration Isolation Foundation Of Ultra-Precision Machining Machine Based On Piezoelectric Material Under Micro Environment Vibration

The ultra-precision machining technology represents the highest level of a country's machinery manufacturing industry,it is one of the measures of scientific and technological level and also an important symbol of comprehensive national strength.How to guarantee and improve the precision of ultra-precision machining is the main reason for restricting the development of ultra-precision machining,while the main factor affecting the machining precision is the micro-vibration during production process.In order to study the response of ultra-precision equipment under micro-vibration and the effect of micro-vibration on machining precision,an ultra-precision equipment was taken as research background and the following research and work are carried out in this paper:(1)The characteristics of micro-vibration and vibration isolation theory are discussed and the environmental factors that influence the precision of machining equipment are analyzed to put forward the theoretical methods and measures to solve the problem of micro-vibration;(2)The intrinsic characteristics of the ultra-precision machine such as natural frequency are obtained by experimental modal analysis;(3)The finite element model of ultra-precision equipment is built,and the theory model of processing machine which is verified through the modal analysis by ABAQUS is contrasted with the test results to provide essential conditions for the subsequent researching;(4)The acceleration power spectrum is used as the excitation input in random vibration analysis in frequency domain to analyze the response of ultra-precision equipment under environment vibration simulated by white noise,the result shows the root mean square value of displacement in all three directions can't reach the requirement of 50nm,and isolation measures need to be taken;(5)A vibration isolation system based on piezoelectric material is designed and the response of the system under micro-vibration is analyzed,the result shows the maximum root mean square value of displacement of table in X,Y and Z direction is 33.5nm,22nm and 6.82nm,while the maximum root mean square value of displacement of knife is 47.7nm,38.8nm and 44.1nm,which can meet the requirement of 50nm,and the maximum vibration isolation rate in X and Z direction reaches as high as 98%;(6)The influence of different vibration isolation parameters on isolation effect is analyzed by control variate method.The results show that the system has a good isolation effect while the thickness of foundation is 565mm and 765mm;the isolation effect of piezo-ceramic actuator depends on the product of the surface voltage difference and the number of stacking layers;to meet the requirement of precision,the less the stack,the higher the voltage required;the isolation system works best in Y and Z direction while the spring stiffness is 2.5×10-4N/m,and it works best in X direction while the stiffness is 3.0 ×10-4N/m;the system has the best isolation effect while the stiffness is 2.5 X 104N/m in general.