Study On The Edge Quality Of Fine-blanking And Its Control Method

Fine blanking technology is an advanced process of metal plastic forming,which can produce much higher precision edge quality of sheet parts than ordinary stamping.It has been abroad used in many aspects such as motorcar,aerial equipments,ordnance,and home appliances in recent years.With the rapid development of manufacturing industry,and Jiangsu province and Delta Region of Yangtze River having the trend of being Chinese center of manufacturing industry,fine blanking technology is entering the stage of rapid development.Targets of this study focused on the edge of fine blanking parts.At the same time,the contents such as the formation mechanisms of parts edge,evaluation method of edge quality, control of edge defects,and predicting of tool wear condition etc.are researched.The main contributions are summarized as follows:1) Compared with ordinary stamping process,the characteristics of the part material in the deformation area such as material flow,stress and strain distribution are investigated.Based on the various condition transformed of mean stress and material damage,the formation mechanisms of parts edge is further discussed.Standing on metal cutting theory,the internal relations between fine blanking and metal cutting is revealed.2)For the first time,the "Edge quality" concept is introduced to the fine blanking,and "Clear cut ratio" which is used to appraise the edge quality is proposed,which has provided the new mentality for the establishment of perfect quality rating system.3)With theoretical analysis,numerical simulation of fine blanking.The orthogonal design method is applied to analyze the formation and the change of quality of parts edge,and distinguish the ordinal relation of different parameters in the control of edge quality.Furthermore,the tool wear mechanism of free blanking was discussed.According to FEM result point out the fault of common simplified simulation method.At last,the author has proposed an improved FEM method for fine blanking.4)According to thorough unscrambling of DEFORM model file,nesting the object-oriented programming language Visual C++ and the script command stream of DEFORM,an parameterized generation system with logical interface for fine blanking FEM model is developed. The feasibility and the credibility of this system is proved by using it to predict the fine blanking edge quality.The working achievement of this paper will enrich and develop the fine blanking processing theory,the main research conclusions will provide important technical and theoretical guidance for improving the edge quality.It has high applied value in control of edge defects and optimum design of blanking tool.