Study On Precision Forging Process And Die Of Tiny-Automobile Cranshaft

The crankshaft is one of the most important forge pieces of automobile. Precision forging technology of crankshaft is the most important development direction for tiny-automobile crankshaft forging technology. For precision forging crankshaft of tiny-automobile, non-quenched/tempered steel will replace other materials. After forging, the forged crankshaft only needs controlled-cold, not needs heat treatment, so it can avoid distortion during heat treatment and save a lot of energy sources. The precision of crankshaft can reach very high level, resulting in that the workpiece needs little machining to be used directly. The process improves producing efficiency and use ratio of materials, decreases producing cost. Therefore the competing ability of crankshaft is improved greatly.This paper briefly introduced the technology of crankshaft die forging and the development status of home and abroad , choosing 133 tiny- automobile crankshaft as the typical forge piece, particularly introduced the work in CAD and CAE of crankshaft die forging.The feasibility, stability,quality of forming (including brimming forming, replicate and organize disfigurement), material utilize efficiency and how to reduce load, how to improve mould life-span are all emphasized when we working out forming process of crankshaft because of its complicated forging process. By the use of the CAD system in UG, the forming process and die of 133 tiny-automobile crankshaft have been set up . In this paper, through adopting rigid-visco plastic finite element method (FEM) and using American advanced software DEFORM. Through FEM simulation, the web thickness of pro-forging pieces, the structure of die and the size of billet are optimized, attained the aim of optimize technology parameter, the structure of die and avoid defect. Analyzed the rule of metallic flow , the stress and strain, the temperature field of forged pieces , and also analyzed the temperature field and stress of the die. Later, through a series of simulations analyzed the relations between friction coefficient and metal filling, the maximal load, the maximal temperature of die. And also analyzed the relations between tool wear and friction coefficient, press velocity, hardness of the die. At the end, validated the rationality of the process and die of the 133 crankshaft through examination, contrasted the results between simulation and examination, summarized the succeed experience.