The Analysis Of Dynamical Charaeteristics Of Precision Horizontal Machining Center

With the development of world economy and technological progress, high-end CNC machining center has become a major tool in equipment manufacturing. It requires high precision machining, and not only requires good static characteristics, but also has a good dynamic performance. This article focus on precision vertical/horizontal machining center product development issues in "high-end CNC machine tools and basic manufacturing equipment", which is special projects of major national science and technology. Firstly, this paper considers reducing machine vibration and improving stability, and then studies the dynamic characteristics of precision horizontal CNC machining center through the method of combining modeling and analysis with the test. Further research has been done in the following aspects,(1) The solid model of five key components of MDH50 horizontal machining center bed, column, spindle box, slipway and worktable are introduced into ANSYS, finite element mesh is division and modal analysis is done. Then normal stiffness, normal damping, lateral stiffness and lateral damping in the rail joint surface is test, which is introduced into finite model of the machine center, and modal analysis and harmonic response analysis are done, and the influence of every part is preliminary discussed.(2) The solid model of the whole machine of MDH50 horizontal machining center is introduced into ADAMS, and bound of five components are established, and multi-body dynamics model is conducted. The flexible rocessing for machine tool bed, column, spindle boxes, slipway and worktabale is done, and the corresponding rigid models in machine are replace with the flexible body, and flexible multi-body dynamics models are built. Kinematics simulation is done after the loads and constraints are added, and the result of which makes the effect to machining accuracy by five components is obtained. Then machine model after the column is flexible is as a research object, and kinematics simulation is done after the first 2-order mode of column is closed, and the impact of low order modes of column is discussed.(3) The test system for dynamic stiffness is set up, and measuring points are arrangement based on the mechanical characteristics of five key components of MDH50 horizontal machining center, and the transfer dynamic stiffness of the key components machine tool bed, column, spindle and spindle box components, slipway and worktable is obtained, and relative dynamic stiffness of whole machine is obtained. The high or low of transfer dynamic stiffness is discussed after contrasting the transfer dynamic stiffness of five key components. Then the result is contrasted with the result from the simulation, and the effect to machining accuracy from transfer dynamic stiffness is analysed, and the effective recommendations for improvement are proposed. At last the accuracy of finite element model is verified after contrasting the relative dynamic stiffness with the result from the finite element analysis.