Stiffness Distribution And Structure Optimization Of Machine Tool Based On Distortion Sensitivity Analysis

The precision of the machine tool is an important indicator to evaluate the performance of machine tools,the deformation error of the machine tools is one of the main source of error in the precision of the machine tool.Therefore,improve the rigidity of the machine tool is an important way to improve the precision of the machine tool.The precision of the machine tool's manifestation is the deviation of the relative position between the tool and the workpiece,The greater the deviation,the worse the precision.The final deviation of the tool and the workpiece is the comprehensive result of the deformation error of various components of the machine tool,However,the influence of mechanical components' deformation error on the final deviation is different,analysis and grasping machine parts deformation error's effect of the final degree of deviation,It is necessary to analyze the sensitivity of the force deformation error of the machine,the results can guide the structure optimization of machine tools.The main contents are as follows:In chapter one,introduces the research status of domestic stiffness modeling and structure optimization of the machine tool,aiming at the deficiencies in the current research,put forward ‘Stiffness Distribution of Whole Machine Tool and Structure Optimization of Parts Based on Distortion Sensitivity Analysis',and expounds the research ideas and the main content.In chapter two,according to the topological structure of lathe,combining the multi-body system theory and homogeneous coordinate transformation principle,the various components of the machine tool's deformation form and the deformation error are analyzed,the various components of the machine tool's ideal characteristic matrix and the deformation error characteristic matrix are confirmed,the deformation error model of machine tool is established.The force deformation error model is universal for the general lathe and has reference value for other machine tools.In chapter three,uses indirect sensitivity analysis method to analyze the sensitivity of all parts of the machine tool deformation error,the analysis results can reflect the influence degree of various components of machine deformation error of the cutter and the workpiece final position deviation,which provides a theoretical basis for the optimization of the structure of the machine tool.According to the deformation error model of the machine tool,a software for the analysis of the deformation error sensitivity of the machine tool is developed.The software is easy to use.In chapter four,based on the results of the sensitivity of the machine tool deformation error,according to the machine deformation error of the components with large deviation in the direction of machining error,select the most effective optimization component and stiffness direction,taking the lowest total cost of the machine tool as the optimization target,using genetic algorithm,and the optimal distribution of machine tool stiffness is completed,the cost savings of about 5.6%.In chapter five,based on the results of the sensitivity of the machine tool deformation error,this paper presents a new method for structural optimization of key components in the direction of sensitive deformation.Aimed at the weak parts' degrees of freedom Sensitive deformation at the direction of the machine error,use the response surface method and finite element method,Under the condition of ensuring the quality of the structure,the bending rigidity of the spindle is increased by 6.2%In chapter six,the research work is summarized and the future research is prospected.