The Research And Development Of NX Based Auto Panels Mold Static Interference Checking

Recent years,3D modeling softwares, such as UG and CATIA, are more and moreused in auto cover mold design. It solved the problems existed in traditional2D design, forexample dimensions are disorder, workload for design is heavy, it requires high forworkers to analyze drawing because of the complex mold structure and so on. But itbrings new trouble such as some hiden interferences are difficult to be found. At the sametime, due to the casting deviation, the mold size is not the same as it is designed. Currentlythe interference checking module on NX platform have some shortcomings, thecomputing time is long and the result is not intuitive. So it is meaningful to develop asystem to solve the interference during mold design which taken casting deviation intoconsideration.The research of this paper was supported by Major national science and technologyprojects(2009ZX04013-031). After in-depth study in mold design enterprises, this papergrasps the requirements of what mold designers need about auto mold interferencechecking. On basis of all of these, a interference checking system named Auto MoldInterference Checking was developed on NX platform.The paper focus on research about interference checking method based on SpatialGrid and Triangle Facet. The basic idea of the algorithm is shelling the solids into trianglefacets and converting traditional interference checking between solid and solid to computethe spatial positional relationship of triangular facets. It brings spatial grid algorithm intocalculation process, also with some other methods to reduce the redundant computation,greatly improves the computational efficiency.The system based on research method contains three sub-modules. Interferencechecking module is used to analyze the entire mold; the hard interference checkingmodule is used to rapidly analyze if there exists hard interference between the mold solids; the soft interference checking module is used to rapidly analyze if there exists softinterference between the solids.The result of Interference checking module uses color maps by marking hardinterference zone, soft interference zone, touching interference zone and safe zone withdifferent color, s that the user can intuitively notice the interference during the mold.Hardinterference checking module uses WAVE function to associate checking solids to the newNX part which used to interference checking. This module can quickly find the hardinterference during the mold and generate result list. User can notice not only if thereexists hard interference but also the extent of interference.After using this system in auto mold interference checking, it is proved to be efficientand reliable.