Error Analysis And Positional Accuracy Control Of Feed System In Machining Center

Improving the accuracy and quality of product is one of goals pursued by modern manufacturing science and technology.The positional accuracy and the repeated positional accuracy of feed system in maching center are the important index for measuring the positional accuracy of numerical control machine tool.The positional accuracy is increased from 0.01mm to 0.005mm,partly to 0.001mm.The research on accuracy is the hot in the area of machining skills.As the machining center has developed in the direction of high-speed and high-finish maching,the product has to be high-accurate and high-qualified.Regarding the operating characteristic,feed system is required to have the good static and dynamic accuracy.It is an important measurement for increasing the accuracy that the error analysis and positonal accuracy compensation are carried out in feed system.The positional accuracy of feed system directly influences the work accuracy of numerical control machine tool.From the perspective of manufacturing and using,this thesis anylizes the error source of the feed system in VDL1200 machining center,and proposes to adjust the backlash and optimize the servo system and compensate the pitch,and debugs by using modern testing tool to increase the positional accuracy.Firstly,the parts influencing the positional accuracy should be changed,and the backlash of mechine driven system should be tested and adjusted;secondly,the servo adjusting optimization software is adopted to optimize the servo system characteristics,to increase the response speed of the servo system,to decrease the tracking error,to increase the machining quality of workpiece surface,and to shorten the machining time;thirdly,the dual-hand laser interferometer is used to test the positional accuracy and the repeated positional accuracy for the pitch error.The previous test data and result of machine tool accuracy is anylized and compensated to increase the positional accuracy and the repeated positional accuracy of machine tool.The ball arm is adopted to test the whole-circle of machining center and analyze the roundness error between two axles and the sevo matching characteristic,to optimize the overall dynamic property of machine tool,and to summarize the method of increasing the positional accuracy of machnining center.Finally,the trial cut of NSA is used to verify the reliability of kinematic accuracy in VDL1200 VMC.By the trial cut verification of the standard roundness-rhombus-square to the compensatory equipment,the result of which proves that the given approaches can efficiently increase the positional accuracy and the repeated positional accuracy,and the machining accuracy meets the national inspection standard.