Error Modeling Analysis Of Five-axis NC Machine Tool

At present, there are still many difficulties for the design and development of largespiral bevel gear NC machine tool in our country.Error statistical sample is limited forheavy-duty NC machine tools, and the use of statistical methods on accuracy is very little.This article studies the precision stability of machine tool through the establishment oflarge spiral bevel gear NC machine tool’s machining precision model, and providestheoretical reference data for machine tool design and maintenance cycle.This paper builds a model of large spiral bevel gear NC machine tool accuracy basedon multi-body system theory, and mainly researches the relationship between error analysis,error verification and kinematic pair wear of numerical control machine tool andmachining precision and machining accuracy stability, calculating the error theory by themachining precision of the model established by theory, and comparing it with errorverification value to improve the accuracy of machine tool.This paper uses two methods to measure and identify error: One is to use inspectionequipment, digital inductive micrometer and other equipment to measure error termdirectly, including straightness error, vertical degree error, position error etc; The other is tomeasurement machine error indirectly by nine lines measurement method and identify theerror terms which identify the first method is not convenient to measure the error term.The paper studies the machine tool slide motion pair X-axis and Z-axis post kinematicpair and Z-axis slider kinematic pair wear, analyzes the influence of every component ofthe kinematic pair wear on the machining accuracy and the influence of Many parts’coupled condition on the precision of machine tool wear; Determines the key parts whichmake influence on the machining accuracy, and combines the machine equivalent worktime with multibody system modeling method to build the machine tool machiningaccuracy model related to wear. Machine tool accuracy stability is one of the majorproblems machine tool research, there are many reasons of the decrease of precision, thepaper mainly analyzes the influence on maintain accuracy between kinematic pair wear parts, deduces the machining accuracy stability model of machine tool on the basis ofmulti-body system theory to predict the machine maintenance cycle.