Design And Research Of Flexible Quick Exchange Process System For Large Thin-walled Cylindrical Structure Parts

The large thin-walled cylindrical structural parts in the aerospace industry have the characteristics of high machining accuracy,many and complex machining processes,etc.,and it is of great significance to realize the flexible quick change between different machining processes.Therefore,this paper designs a flexible quick-change process system according to the processing characteristics of the above large-scale thin-walled cylindrical structures.In addition,the reliability and accuracy of the flexible quick-change process system for large thin-walled cylindrical structural parts are the most important for the workpiece processing process,which not only has an important impact on the qualification rate of the workpiece to be processed,but also effectively shortens the process preparation time and improves the processing efficiency.have a positive effect.Therefore,it is of great practical interest for aerospace manufacturing enterprises to design a flexible quick-change process system for large-scale thin-walled cylindrical structures and study its reliability and accuracy.Based on the design principles and methods of domestic and foreign products,this thesis carries out the analysis of extreme working conditions of large thin-walled cylindrical structure parts in the machining process,and carries out the mechanical analysis of turning and milling of large thin-walled cylindrical structure parts,which provides the design basis for the layout and optimization of flexible rapid change process system Through theoretical calculation,the maximum cutting force of large thin-walled cylindrical structure was analyzed under extreme cutting conditions,and the maximum milling force of large thin-walled cylindrical structure was obtained under extreme cutting conditions.After comparative analysis,the extreme cutting conditions were selected as the design basis of flexible quick change process systemIn order to obtain a flexible quick-change process system for large-scale thin-walled cylindrical structural parts that meets the design requirements,it is necessary to conduct a detailed analysis of the layout schemes of different zero point positioners.Firstly,the initialization layout model of the flexible quick-change process system is constructed according to the characteristics of the workpiece,and the mechanical verification analysis is carried out.Then,a recursive optimization algorithm for the position and number of the zero point locator of the flexible quick-change process system for large-scale thin-walled cylindrical structural parts based on genetic algorithm is proposed.And its layout is checked and calculated by force;finally,through comparative analysis,it is determined that the layout optimized by genetic algorithm is the design scheme of flexible quick-change process system for large thin-walled cylindrical structural parts.Mechanical simulation is an important step in product design.This thesis studies the error change of the flexible quick-change process system for large thin-walled cylindrical structural parts under the action of multi-stress coupling through mechanical simulation.Error changes during clamping and machining,and calculate the error values caused by transposition,clamping and machining.Through calculation and discussion,the error changes in each functional link meet the design requirements.In order to achieve the most important precision technical indicators of the product,a detailed analysis of the product error situation is required.Firstly,the error prediction analysis of the flexible quick-change process system is carried out by using the Monte Carlo method,and the part tolerance optimization design is carried out according to the analysis situation,and the optimized prediction error value meets the design requirements.Finally,the functional verification is carried out through experiments.Compared with the predicted results of Monte Carlo method,the measured values are within the predicted value range.