Research On Composite Technology Of Cross Wedge Rolling (CWR) And Forging For The Two-Cylinder Crankshaft By Numerical Simulation

The crankshaft is the core rotating part in automobile engine,which role is to bear impact load and transmit power.The conditions of the crankshaft during operation are extremely terrible.If the crankshaft is damaged,it may cause serious traffic accidents.The traditional forming process has certain limitations,so it's urgent to explore a new efficient and energy-saving forming technology.Therefore,this paper proposes a composite forming crankshaft technology,namely: rolling and forging composite forming-the composite technology of cross wedge rolling billet and die forging forming crankshaft.The research object of this paper is the double-cylinder crankshaft,the plate-shaped cross wedge rolling blank mold and the forging die of the double-cylinder crankshaft are designed,and the finite element model is established.Based on the finite element simulation software,the double-cylinder crankshaft rolling and forging composite forming process is systematically studied.The optimal design rules of the blank size required for die-forging a double-cylinder crankshaft were revealed.The bi-direction eccentric stepped shaft blanks and blank-forging double-cylinder crankshaft was numerically simulated,that aim to discuss the feasibility of crankshaft rolling and forging.The crankshaft connecting rod journals are distributed in the radial opposite directions.First,the feasibility of rolling the bidirectional eccentric stepped shaft is verified,which provides a theoretical basis for rolling the crankshaft die forging blank.Based on the shape and size of the crankshaft,this paper designs nine blanks with different sizes and different eccentricity,and uses DEFORM-3D to simulate the crankshaft forging process.According to the forming quality of the die forging crankshaft,the end design of the die forging blank is optimized,so as to provide a basis for the design of the plate-type cross wedge rolling blank mold.Secondly,in the research process of the crankshaft rolling and forging composite process,the rolling die forging blanks of cross wedge rolling were studied,and the metal flow law,temperature field,equivalent stress and strain distribution and process parameters during cross wedge rolling were analyzed.Effect on rolling force.The double-cylinder crankshaft die forging was studied,and the effects of billet temperature,upper die pressing speed and friction factor on the forming load,temperature field,stress and strain,and die wear during the die forging process were analyzed.Using the orthogonal optimization test,the optimal process parameters at the stage of crankshaft forging are analyzed.Finally,the dual-cylinder crankshaft rolling and forging composite process is compared with the traditional die forging process to summarize the advantages of the rolling and forging composite process for forming the crankshaft.