The Dynamic Analysis And Optimization Of Precision Machine Tool Bed

With the rapidly development of Precision machine tools in higher speed, higher precision and higher flexibility, besides the requirement of machine's weight being light, lower cost, convenient application and good technical capability, higher and higher machining capability is also demand. Machining capability includes machining quality and cutting efficiency. Machine's machining capability is usually assessed by the tiptop precision and superficial roughness that can be reached of the being processed part. The cutting efficiency is usually assessed by the most limit value of removal rate or cutting dosage. And machining capability is closely correlation with machine's dynamic capability. It is proved that the demand of machine's dynamic capability is higher and higher with the improvement of machining capability.The machine tool bed is an important component for machine tool, thus its dynamic capability will directly influence the accuracy of the machining. The structure of the precision machine tool bed is made up of basic frames. The distribution of the rib wall and the hole size on the rib wall which compose the machine tool bed will influence the dynamic capability greatly. As a result, how to put out the rib wall and choose the hole size on the rib wall is a key point to improve its dynamic capability and economy the materials used and cut the cost.This thesis analizes the factors which will influence the dynamic capability of the machine bed, taking the vertical machine center 750 for example. First, the FEM model of the machine bed is setup with its dynamic analysis to find the weak points. Then, through the analysis result for the anti-vibration, the inner structure of the bed is improved. It contains three aspects: firstly, several kinds of typical scheme for the rib wall is put forward and analyzed. A rational scheme for the rib wall is choosed. Secondly, typical unit structures (US) of the lathe bed are picked up and optimized. Thirdly, depending on optimized results of unit structures, the improved bed schemes are presented and analyzed. According to the analysis based on the scheme, the dynamic capability of the lathe bed is improved a lot.