Failure Analysis And Design Improvement Of Automobile Chassis Assembly Tightening Bolt

With the development of our country industry,especially introduce from famous company,for example the technology Germany Volkswagen Company,American General Motors Company,France PEUGEOT-CITROEN company producing together,even understanding the advanced design and the manufacturing idea of equipment.The technology of bolt and nut is sustained development,from single tightening torque to double control of torque-angle.Bolt and nut link as the most usual,the most important connection way,has been one of the most important research subject on mechanical connection,include China in every country in the world.The research objection is that attachment bolt both rear axle stand and wheel shaft diameter in Shanghai Passat car,to analyze and make a survey on failure phenomenon,to get failure situation,and to check on particular index.On this basis,to carry on the relationship of frictional behaviour,bolt equivalent strength,the pulling force on the axle,and tightening torque,and to carry on force analysis and strength calculation,then to identify, finally to proposed optimization scheme,and to improve performance.Mainly include the following aspects:1.According to Failure analysis of bolt connection and whole project inspection,to analyze the causes of failure,and to check on.2.0n the basis of investigating,to make a research improvement plan,and to improve mechanical properties.3.According to stress state of bolt connection,to analyze and to identify,and to have an intensity of the reexamination.4.According to heating treatment and stress analysis of raw materials,to improve and to control the technological measures,successfully to completed the assembly of low strength bolt.As to this phenomena of the bolt-on connection becoming soft,the paper starting from materials,mechanical properties,heating treatment and friction property,have the stress state of bolt connection and strength calculation,and have an analytic study ofwhy the bolt becomes long,becomes thin,breaks,finally have a determination to improve the performance of bolts with torque control and process improvement.