Study On Measuring Method Of Dynamic Rotary Precision Of Spindle Rotation Under Load Condition

The spindle rotary precision is an important factor affecting the machining accuracy of the workpiece in the process of parts processing.At present,most of the researches on spindle rotation accuracy are in idle state.For the machining conditions,there are few studies on the measurement method of spindle rotation accuracy.But only the rotation precision of the spindle measured under the processing condition can reflect the performance of the spindle and the precision of the machining accuracy,therefore,this paper analyzes the spindle rotation error measurement of load conditions and difficulties of research design method for measuring rotary precision of spindle load conditions.In this paper,a new measuring method is designed to solve the difficult problems in measuring the spindle rotation accuracy,based on the basic problems of rotation accuracy and the evaluation criteria of spindle dynamic rotary accuracy.The contact acceleration sensor is installed on the outer casing of the spindle.The vibration transfer model between the pick-up point and the spindle is established,and the vibration signal of the spindle can be obtained by picking up the signal of the vibration point.The bearing stiffness in the model is calculated based on the Hertz theory and the least square method.Based on Hooke’s law,the stiffness of the base in the model is calculated by using the ANSYS software.The correctness of the model is verified by experiment and simulation on the 170XDS20Z11 spindle.The error analysis of the time frequency domain integral method is carried out by the principle and the simulation.The cumulative error of the time domain integral is separated by the method of the detrending term.Thought Band pass filtering method to separate frequency domain integral low frequency amplification error.Experiments are carried out on three kinds of rotational speeds on the JS2D170C-12/15 xj type spindle,and the integral accuracy of the two integral methods after the error separation is evaluated.Getting the spindle radial gyration trajectory and axial vibration trajectory by integral,and using the four method of roundness assessment by evaluation of the coordinates of the center,so as to obtain the radial rotation error of the spindle value through time-frequency conversion according to the definition of axial dynamic rotary precision filter was spindle rotary axial error.The user interface is designed by using Matlab software,according to user interface design criteria,a spindle rotation accuracy measurement interface is designed,and the main shaft theoretical algorithm part is packaged.In order to test the measurement method in this paper,the method of this paper is compared with the American lion spindle rotation accuracy analyzer in the mu 2000/5ss-800 H machine tool.Finally,we put the paper into the actual cutting,and analyze the relationship between the rotation precision and the speed and the depth of the cutting under the machining condition of the spindle.