Geometric Error Analysis And Measurement Experimental Research Of Five-axis Ultra-precision Machining Machine

Ultra-precision machining technology is applied more and more widely and the shape of parts is more and more complicated.Therefore,increasing the number of axes is the current development trend.However,for ultra-precision machine tools,including five-axis ultra-precision machine tools,the direct method is not only time-consuming and laborious,but also combined with empirical judgment.Indirect methods are difficult to filter installation errors and to evaluate specific error items.Therefore,this paper takes the five-axis ultra-precision machine tool as the research object,the club instrument as the measuring instrument,and adopts the indirect measuring method to conduct in-depth research on the geometric error modeling,measuring method and experiment of the fiveaxis ultra-precision machine tool.Mainly includes the following aspects:In order to establish the geometric error model of the five-axis ultra-precision machine tool,the causes of some errors of the five-axis ultra-precision machine tool and the influence of the errors on the five-axis ultra-precision machine tool are analyzed.Based on the multi-body system theory and the spatial layout of the machine tool,the topological structure of the machine tool is obtained,and the error model of the five-axis ultra-precision machining machine tool is established.In order to measure the total geometric error of a five-axis ultra-precision machine tool,a measuring method is designed based on the use characteristics of the club instrument.The direction of the club instrument is always the same when the machine tool is linked by five axes,so that the combination of sensitive error items in this direction is always the same during the operation of the machine tool.In order to accurately install the club instrument to the designated position,the steps of installing the club instrument and the measures to reduce the installation error are analyzed.In order to filter out the installation error,the causes of the installation error and its influence on the measurement results are analyzed.From the measurement data of YCX three-axis linkage and ZBX three-axis linkage,the installation deviation of the two precision balls of the club instrument is calculated respectively and used to filter out the installation error in the measurement data of five-axis linkage.In order to evaluate the influence of interpolation process,the causes of interpolation error and its influence on measurement results are analyzed.The measurement experiment is carried out on the machine tool,and the installation error and high frequency dynamic error are filtered out successively from the measurement data to obtain the total geometric error and its components in X,Y and Z directions.In order to further evaluate some geometric errors of the machine tool and put forward adjustment suggestions for the machine tool,through comprehensive analysis of measurement results of linkage movement of different shafting numbers and measurement results of positive and negative linkage operation,the error items with larger weight,bad geometric error items and their positions with larger influence are determined,and suggestions are put forward for the adjustment of the machine tool.Through the comparison between continuous operation and intermittent operation measurement,the rationality of using continuous operation measurement results to explain geometric errors and using low frequency signals to describe geometric errors is verified.Through repeated measurements,it is proved that the measurement results have good repeatability.