Migration Mechanism Of Assembly Accuracy And Design Method Of Assembly Process In Heavy Machine Tool

Heavy machine tool of CXK5463 is a special machine for machining component of water chamber head, its weight is 150 t, length of beam is 10.4 meters. Therefore, it has a long distance constraint of assembly process. the complexity of loads and they have a large range of variation, formation and maintain of assembly accuracy is changeable. Existing design of assembly process make geometric constraint as goal, main design requirement is geometric parameters of assembly bodies, conduct assembly process and blurry physical constraint as assembly method, for solving conflict problem between geometric constraint and last assembly accuracy, this assembly process adopt trial and error to blow grind surface, compensate and repair surface behind overtolerance of assembly accuracy, this assembly accuracy have passivity and cannot identify formation and its evolutive process effectively, its mechanism of growth and transformation cannot clearly defined, therefore, as a driven goal of evolutive process of assembly accuracy and a design object of assembly process, as a design variables of key assembly variables in key process and propose a initiative design method. For this reason, this thesis make CXK5463 of heavy turningmilling machine center as research object, mainly finished as the following content:Aim at characteristics of changing of assembly accuracy with process implemented, get through setting up mapping relation between deformation fields and assembly accuracy indexes, put forward notion of assembly accuracy migration and reveal its characteristics, take function method of Heaviside, gain key assembly process of assembly accuracy migration.Use FEM method of response surface, identify key assembly variables of assembly accuracy migration, adopt Topology optimization of FEM, analyze sensitivity of deformation fields to key process variables, employ method of AHP, build matrix of assembly accuracy migration and mapping matrix of assembly variables, measure relationship between assembly process variables, reveal mechanism of formation and growth of assembly accuracy migration, propose design method of assembly process in heavy machine tool and conduct example verification.Via analyzing characteristics of repetitive migration of assembly accuracy, employ method of AHP, reveal hierarchical relation of control variables of assembly accuracy migration and build criterion of repetitive migration of assembly accuracy, adopt Multi-objective driven optimization method of FEM, optimize level of key assembly variables and propose design method of repetitive assembly process. Aim at characteristics of stress fields in running process, use arithmetic of LS-SVM, forecast stress fields of machine running and conduct verification of example.For studying characteristics of deformation, reveal significance of control variables to deformation fields in worktable components, and ascertain key control position of retentivity of spindle components, exploration of assembly accuracy migration process in worktable components under alternating load, put forward control method of reliability enhancement, analyze thermal-mechanical coupling in Ram components and reveal sensibility of key surface to deformation of front face in ram, and conduct experiment of machining water chamber head.