Research On Key Technologies And Application Of Complex Model Partitioning Manufacturing

With the development of world economic integration and manufacture globalization, competition of manufacture market is more intensive than ever. Requirements of customers are tending to diversification and individuation and the life span of a product tends to be shorter than before. All these promote the development of rapid design and rapid manufacture. More and more advanced manufacture technologies, such as rapid prototyping and partitioning manufacture, spring up and are applied speedily.Subjecting to manufacturing resource, cost and lead time constraints, sometimes,a complex product or model can not be machined as a whole, and need to be partitioned into a number of smaller and simpler manufacturable pieces. After manufactured,the individual pieces can be assembled to get the original product or model. That technology is called partitioning manufacture technology. It can reduce requirements for process equipment, shorten the periodicity of design/trial manufacture and decrease development cost, and it also can be used in industry widely, not only in various complex parts or its prototype processing but also in the automation of mold design and manufacture.In previous researches, all composed faces of the model are taken as the research objectives or triangle facets modeling is built first and triangle facets are treated as objectives. These methods will result in low computational efficiency and for triangle facets modeling is approximate model, it will cause low precision. Considering the achievement of feature technology during last decades, features are introduced into partitioning manufacture as the objective investigated for the first time and it can avoid the above shortages. At the same time, features introduction is propitious to CAD/CAM integration.Machinability analysis is an important part across partitioning process and is the crucial factor to decide whether to execute partitioning. In this paper, visibility analysis is instead of machinability analysis and a global visibility analysis algorithm is proposed. Firstly, local visibility is obtained using VMap ; and then each feature with local visibility will be analysis further. Global analysis result can fit for production equipment.For the first time, a multi-objective optimal algorithm is proposed to get the optimum partitioning scheme. In the algorithm partitioning pieces number, material utilization, machining features and partitioning area are considered synchronously to build objective function. Genetic algorithm is taken to implement the multi-objective optimal. In this paper, a combination algorithm is introduced to reduce the partitioning pieces number, machining features and partitioning area further. Combination of redundancy partitioning piece is propitious to optimal partitioning schemes. At the same time, an emerging multi-piece mold design is investigate and automatic mold design is realized in this paper.Based on the above key technologies research, using Visual C++6.0 and UG/OPEN API on the platform of UG NX, a prototype system of intelligent CAPP and integration with CAD/CAM in mold digital manufacturing is developed. Two typical parts of plastic mold are used to validate the feasibility and validity.