Research On The Accuracy Retention Test And Evaluation Method Of VMC850E Vertical Machining Center Guide Pair

Based on the national science and technology major project,aiming at the main problem that there is a big gap between the domestic rolling linear guide pair and the developed countries in terms of accuracy retention,this paper selects a domestic model of guide pair as the research object to reconstruct the VMC850 E vertical machining center and build a test bench.In order to provide reliable data and theoretical support for the further upgrading of the accuracy retention of domestic guide pairs,a comprehensive study on the test method,data analysis method and evaluation method of the accuracy retention of guide pairs is carried out.First of all,in the design of the precision maintenance test bench for the guide rail pair and the formulation of the test plan.Combined with the characteristics of the guide rail pair,the basic performance requirements of the test bench were clarified,and the VMC850 E vertical machining center was transformed.The mechanical structure part,the measurement and control hardware system part,and the measurement and control software system part were mainly researched to ensure that the test bench can realize the loading and running function With online data acquisition capabilities.Comprehensively consider factors such as the accuracy retention test characteristics and test equipment life,and formulate a feasible accelerated life test scheme.Then,in terms of test data processing.The system summarizes the process of the precision maintenance test data of the guide rail pair,including how to convert the recorded data into the accuracy index value,the processing of abnormal test data,the specific failure time of the guide rail pair and the distribution hypothesis test by the accuracy index value,and Complete the drawing of the precision decline curve of the guide rail pair.Finally,in terms of assessment methods.Combining the characteristics of this test as a small sample and accelerated life test,the virtual augmentation theory method is used to process the failure data,and based on this,two-parameter and three-parameter Weibull distribution models are established,and the parameters of the two distribution models are studied in depth.Estimate the method and perform a goodness-of-fit test to determine the optimal solution.On the basis of the above work,the point estimation and optimal confidence interval estimation of the guide rail reliability index values are obtained through analysis,and the test evaluation is completed.Based on the evaluation results,the rated dynamic load of the guide rail pair selected for the test was appropriately corrected,and by observing the quality performance of the test samples after the test was completed,a comprehensive evaluation of the accuracy of the guide rail pair was performed.