Research On Feature Recognition Method Of Sheet Metal For Home Appliances And Development Of Process Model Interactive Design System

The sheet metal parts of home appliances have complex shapes and many forming processes.The design of their process models is the core of stamping die design.The traditional design method is mainly 2D design,which has high efficiency,but it is difficult to express the forming process of complex parts.the 3D process model is manually designed using general 3D software,which is very inefficient and difficult to promote and apply.Therefore,the development of a 3D process model design system with high design efficiency and simple operation has important theoretical and application values for the design of sheet metal stamping molds.This article combined with Midea ’s Automatic Design System of Sheet Metal Die for Home Appliances project,proposed a method of sheet metal feature recognition considering the forming process,and applied the recognition results to the process model design.Based on the NX11 platform,an process model interactive design system of sheet metal for household appliances was developed.The system transforms the process model design from traditional drawing design to interactive design,which improves the design efficiency.A process model design method based on sheet metal feature recognition was proposed.The main idea is to sequentially perform automatic sheet metal feature recognition and intermediate process sheet metal feature unbending in the reverse order of the forming process.Provides tools for human-computer interaction for features that require user definition and processing.A method of sheet metal feature recognition based on classification was proposed.According to the connection relationship between the feature and the model,the sheet metal features are divided into two categories: internal features and external features.According to the position relationship between the features and the seed face,the internal features are divided into three categories: through features,concave features,and convex features.The recognition process of each class of internal features and the recognition process of bending features are proposed,and a group search algorithm applied to the recognition process is developed.The storage and management of features in the system are designed,including the interaction between the core functions of the system and the database and the management of feature unbending process.The process editing function is designed based on parametric modeling technology.By maintaining the correlation between the process bodies and removing the parameters of the feature unbending process,the update time during process editing is greatly reduced.The feature unbending rules for typical sheet metal features were established,and an algorithm was developed to fit plane curves using lines and arcs.A microwave oven door was used as an example to test the system.The test results were compared with traditional drawing design methods.The results show that the system has high practicality and significantly improves the efficiency of process model design.