The Stiffness Modeling And Layout Optimal Design Method For The Support Structure Of Precision Horizontal Machining Center

The supporting pad iron serves as an important component of a precise numerical control machine tool,and the static rigidity of the machine tool has an important influence on the static rigidity and the machining precision of the machine tool.For the static rigidity parameters of the supporting pad,the existing domestic pad iron production manufacturer does not have an explicit design theory and technical specification,and the selection type of the cushion iron in the design and installation process of the machine tool is lack of a basis.Therefore,the method for researching the static stiffness of the high-performance supporting pad iron is mainly studied in combination with the national scientific and technological major special subject research task.The static dynamic characteristic simulation technology of the machine tool with the static rigidity of the cushion iron is considered,a support pad static stiffness test detection and model correction method,and the static characteristic of the domestic precise horizontal machining center is improved.The main research work is as follows:On the basis of the fractal theory,the contact stiffness model of the support pad iron combination surface and the structural stiffness model of the support pad iron component are constructed.The method for solving the tangential and normal static stiffness of the supporting pad iron is given.The normal load is analyzed,and the influence rule of the surface morphology parameters and the component material attributes on the static rigidity of the supporting pad iron is determined.On the basis,the optimized design of the high-performance supporting pad iron structure is carried out by combining with enterprise requirements,and provides a corresponding design scheme.For a certain precise horizontal machining center,a complete machine finite element model taking the elastic support constraint condition into consideration is constructed,and the influence rule of the static rigidity of the supporting gasket on the static and dynamic characteristics of the whole machine is analyzed.The matching principle of the rigidity of the supporting pad and the weight of the lathe bed is provided.On the basis,the multi-objective optimization of the three-point supporting position parameters of the t-shaped bed is carried out,and a supporting point position parameter capable of meeting the requirement for the deformation error of the guide rail is obtained.A machine tool support pad iron normal and tangential stiffness test platform and data acquisition and analysis system software are developed.The test system adopts a high-precision force sensor and a displacement sensor,and has the advantages of being high in testing precision,friendly in interface,and convenient to use.Normal and tangential stiffness testing under different load conditions are carried out on the newly developed supporting pad iron,the theoretical model is corrected by utilizing the test data,and the correctness of the theoretical model is verified.