Structural Optimization Design Of The Supporting System For Vertical Machining Center

The structure-design of NC machine tool is an important part of the high-end equipment manufacturing industry. With the development of Chinese manufacturing industry facing the important strategic opportunities of the transformation and upgrading, we need to speed up the digital structure design process, to grasp the weak links of the machine tool structure, researching design and development, analysis and evaluation, improvement and optimization of CNC machine tool has become the main problems to be solved. Based on this, this paper puts forward the structure optimization design of supporting system for vertical machining center. It takes support part as the foundation, through the analysis of static performance of supporting system on integrated and slip coupling, the sensitivity extent associating machining precision with each component displacement is established to get high contribution rate of supporting structure.This study was supported by National Key Science & Technology Special Projects (No.2012ZX04010011/03). Based on the design process of the research group proposed support model design, topology optimization design, structure concept-unit design and performance calculation and evaluation, this paper investigates the simulation of the static performance involved in cutting action using Finite Element Method, and extracted from the structural optimization design method of the supporting system. Focusing on the design process of the supporting system, following work is contained in this paper:1. Research on static finite element analysis of supporting system for vertical machining center. Taking a three-axis machining center for example, the theoretical basis, calculation process, operation method and application of FEM can be developed, including finite element model and the equivalents on screws, rolling guide and screw-nut pairs so as to simulate the static displacement field of components.2. Sensitivity analysis of supporting system for vertical machining center. According to the description of the topological structure, the correlation between support part displacement and machining precision can be developed based on the homogeneous coordinate transformation, and then the variety of static machining precision is associated with support part parameters using sensitivity analysis, which estimates the influence of support part parameters. The result indicates that the column is the weak link of machine tools. 3. Study on the static stiffness experiment of vertical machining center. This section illustrates test process of the whole-machine static stiffness, including test principle, test apparatus and test contents, summarizes test note and records machine relative displacement under the gradient loading. Through a comparative analysis of the test data, static finite element analysis and correlation model is effectiveness.4. Optimization design of supporting structure for vertical machining center. Based on sensitivity analysis, the topological optimization of the column that has significantly effect on machining precision is developed so that proposes panel and unit design aiming at strain energy of the dynamic and static combination. Subsequently, considering the tool maximum deformation, weight and natural frequency of the supporting system, size optimization method involved in panel, strengthening rib and unit of the supporting system is established. Ultimately the rigidity of the supporting system can enhance 5%-11% under the condition that the weight of the supporting system is not higher than the original plan.