| Hardened steel has excellent mechanical properties and is widely used in mold manufacturing, the aviation and automobile manufacturing. High-speed milling is main process method in cutting hardened mould steel with the advantage of high productivity, high machining quality, low deformation and little cutting fluid, which has been a key development high-tech in world manufacturing. However, tool rapid wear, forced vibration caused by the centrifugal force and dynamic cutting force in high-speed milling hardened steel and uncertainty of a suitable simulation model for parameter optimization lead to a conservative selection of cutting parameters, which are the problem needing to solve urgently in the applications and development of high-speed milling hardened steel, seriously affecting the performance of high-speed cutting technology and constraining the development of the manufacturing sector at the same time.Based on high-speed cutting theory and related research results, a modeling and simulation of dynamic milling force, tool wear and tool vibration is researched in this thesis under cutting kinetic theory, cutting vibration theory, finite element method and numerical analysis.Based on the process analysis of high-speed milling hardened steel and tool rapid wear, a analysis that the effect of cutting force caused by the chip deformation and tool flank wear on dynamic cutting force is carried out in high-speed milling hardened steel, a dynamic milling force model is established in high-speed milling considering tool flank wear; With the conditions of dynamic milling force, tool parameters and cutting parameters, cutting force caused by tool wear is solved and tool wear model is established; A high-speed milling state identification method is presented based on dynamic milling force and tool wear VB value.Studied on the tool forced vibration in high-speed milling, a model of tool forced vibration under joint action of centrifugal force caused by tool unbalance and dynamic cutting force is constructed with the cutting dynamics theory and numerical analysis methods; a modal analysis and a transient analysis of high-speed milling cutter are carried out by the use of finite element methods and the coefficients of tool vibration model are identified.Based on the above mathematical model of dynamic milling force, tool wear and tool vibration, the corresponding simulation model of face milling cutter and ball cutter are obtained in matlab / simulink environment; Based on the above simulation model, a feature analysis of dynamic milling force and tool vibration is made and the effect of the cutter structural parameters and cutting condition on the tool vibration is studied; Tool vibration and tool wear simulation model is validated by the experiment of tool vibration and tool wear in high-speed milling hardened steel.A method of studying on dynamic characteristics of cutter is provided in high-speed milling hardened steel; The simulation model of the dynamic milling force and the tool vibration in matlab / simulink environment provide a basic platform for cutting parameters optimization. |
