Research On Numerical Simulation Modular Organization For Deep Drawing Process Of Complex Shape Cover Body

In recent years, with the development of pressing technology, many large automobile corporations take the ability of design and production as an important symbol of car research level, especially for saloon car, and the main equipment for producing the bodywork is the mould of cover body. Do not as the general drawing parts; the cover body has the characteristics such as many bend surfaces, large dimension, thin material, complex structure shape and high precision requirement. Its mould producing technology is difficult and expensive. Further more it is not easy to control exploitation cycle and quality. As one of the modern producing methods, the technology of CAD/CAE/CAM used in the manufacture of cover body mould can greatly shorten car researching cycle, improve producing efficiency and market competitive power.With the fast development of computer hard and soft wares, finite element method (FEM) and computer graphics, the computer aided engineering technology based on numerical simulation is used widely in metal plastic forming field. The simulation of metal forming processes can be realized in the computer. The deep drawing of sheet metal can be studied with three-dimensional FEM. The distribution of the stress and strain can be obtained in work piece. The forming laws of the work piece can be predicted. The numerical simulation is a powerful tool for the process and design and dies design. In recent years, it is the developing trend of metal forming technology to use advanced methods, such as numerical simulation, to solve the problem in industry. The deep drawing process of complex shape cover body and its key process technology are researched in this paper by the way of numerical simulation.The paper analyses the actuality of simulation technology. It combines the CADand CAE in modular organization. Based on the characteristic of complex shape cover body, the professional 3D sculpting software-PRO/E of PTC Co. is used to design structure and bend surface. The sheet metal shaped simulation software DYNAFORM of ETA Co. is used to carry 3D finite numerical simulation for drawing process of complex shape cover body. It can analyze the drawing quality of sheet metal. Based on the result, it can give an optimize project. A simulated system for drawing process of complex shape cover body can be formed at last.The paper uses the engine oil pan which is one representative work piece of complex shape cover body as researching object. At first it is sculpted in 3D. In PRO/E system, the whole bag of tricks of entity sculpt technology such as extend, cut, round, shell etc. are used to design the engine oil pan and its drawing piece. The product is finally abstained not only in the quality but also in the visual sense. Then, based on the design of drawing piece, the design of the drawing die and punch are finally finished.The paper set up the 3D finite element model based on the CAD model. One step drawing techniques is used as the researching object. The surface element number and friction modulus are selected to simulate the drawing process. After a lot of simulations, we can analyze the effect of former parameters in the drawing process through the simulated result. Then the fitting element number and friction modulus are confirmed, which can meet the requirement of the simulation.The drawing process of engine oil pan mainly includes one step drawing techniques (OSDT) and two step drawing techniques (TSDT). Because of high efficiency and simple mould, it would have more fact meaning if OSDT is used as researching object. After many simulations, several factors such as border force, original velocity of die and drawing beam are confirmed to affect the quality of process. Small border force will produce crinkle. Over large border force will crack. Drawing beam can improve the resistance of feeding material, which is propitious to form the slope part. Drawing beam also can improve the rigidity of engine oil pan and reduce the spring back, slack, distort, ripple and shrink etc. Farther more it can prevent the hanging part to produce crinkle and aberrance in drawing process. Thesefactors can be confirmed through analyzing their effect on the result of simulation. Thus the drawing process of engine oil pan can be optimized and enhance the quality of it.The complex shape cover body is a kind of drawing work piece which use widely and shaped complex. Because this kind of parts is simulated in various means, the paper gives a modular organization system for this kind of parts to simulate the drawing process. Then it can supply instruction for utility research of complex shape cover body.