The Technology Of Drawing Die Digital Repairing Based On DYNAFORM Software

Due to lack of accurate repairing data in defect area as support, and rely heavily on the operators’ mould repairing experience, it is difficult for traditional drawing die repairing method to ensure a mould repairing quality highly; and also, it’s necessary to test the repaired mould and adjust the stamping parameters repeatedly, which make the mould repairing cycle extending and the repairing costs increasing. In order to acquire the accurate repairing data, ensure the quality of mould repairing and shorten the mould testing duration, the technology of drawing die digital repairing based on DYNAFORM software has been studied in this thesis. The main research contents are as follows:First, an ICP-based algorithm is proposed to extract mould defect area automatically. On the basis of the ICP algorithm research, this paper puts forward an ICP-based algorithm for extracting mould defect area automatically, and applys it to achieve the defect extracting and digital repairing of a vehicle door drawing die, which provide an important defect-repaired mould model for the latter stamping simulation to inspect the mould repairing effect.Next, the related theory of drawing die sheet metal forming is studied. This paper analyzes the relevant stamping forming theory and material model in stamping simulation, summarizes the factors affecting the forming quality of a plate and the generation mechanism of common forming defects as well as the frequently-used methods for reducing or eliminating those defects. It establishes a firm theoretical foundations for the stamping numerical simulation and optimization.Then, the research of the stamping forming simulation based on the vehicle door defect-repaired mould model is achieved. This thesis analyses the stamping forming process planning of the vehicle door defect-repaired mould, summarizes the quality evaluation methods of stamping forming. Based on DYNAFORM software, the mould addendum is completed and the stamping finite element model is established. According to the stamping simulation result comparing of different draw beads structural arrangement, it shows that the structure with four draw beads should be adopted to obtain a satisfactory forming quality.Finally, the paper optimizes the stamping process parameters of the vehicle door defect-repaired mould, and verified the defect repairing quality. Orthogonal experiment design method is used to arrange the stamping simulation experiments, and set the experimental evaluation index, the factors (stamping process parameters) and levels. In the first place, a group of preliminary orthogonal experiments are planned for obtaining a reasonable draw beads resistance coefficient range; then, further orthogonal experiments are arranged for optimizing the stamping process parameters, which are applied to verify the forming quality of the vehicle door defect-repaired mould and evaluate the defect area repairing effect. Getting the final optimized stamping process parameters and the defect area model, which will be good guidance for mould remanufacturing physical repairing.