Analytic model of machining errors for thin walled parts based on the deformation of the workpiece-fixture system

摘要

The analytic model of machining errors caused by the deformation of workpiece-fixture system is put forward for the thin walled parts. To facility the analysis, the traditional mathematical model of tolerance zone is redefined. According to the deformation value of workpiece-fixture system calculated by FEA (Finite element analysis), transform matrixes of workpiece location and cutting points deviation have been constructed. So that location changes of the surface machining points can be acquired. Then machining error model is formulated to describe the deviations caused errors. Further for given surface tolerances the sensitive matrix is constructed to evaluate the influence of locators on the machining errors. The model has great potential to be applied toward fixture design verification and process design evaluation. Finally a study case is used to support and validate the proposed model.