Analysis And Improvement Of Dynamic Property Of Machine Tool Structure

In order to improve the capacity of NC machine tool,it must have excellent static and dynamic property. In this dissertation, how to use EMA, FEM and emulative technique to analysis and improve the structure will be studied, two example are provided, one is how to restrain the forced vibration of four-bar linkage of finishing lapping machine, the other is how to improve the structure of bed, glide plate and workpiece headstock according to the result of EMA and FEM. Main content is listed as following:1. In this thesis,reviewed the development and present situation of the fields of dynamics design of NC machine tools. Then, introduce the technology of CAE, FEM, CAD, CAE and emulative technique, which support dynamics design. Finally, stated the research content of it.2. Analyze the dynamic characteristic of finishing lapping machine and do impact modal experiment and test vibratory magnitude. Find the weakness and decide the case of vibration suppression.3. Effect of coupler of aluminium alloy is analyzed, and its intensity is checked by FEM. Case of adding count-weight is computed, its effect and influence to bear loading is confirmed.4. The result of experiment shows the case is availability without the finishing lapping head. But vibratory magnitude is increasing with the finishing lapping head and counter-weight. Adding pretightening force of guide is a way to restraining the vibration, summarize the problem of assembling.5. How to use the technology of EMA and FEM to evaluate the static and dynamic characteristic of gear milling machine. Weakness of the structure is found. Modify bed, glide plate and workpiece headstock according the the theory of unit structure.