Research On Cylinder Bore Distortion Of Gasoline Engine

Combustion engine is the core of automobile. It has a direct influence onpower performance, economy and reliability of the vehicle. Cylinder block isone of the most important parts for the engine. Cylinder bore distorting becauseof bearing thermal load and mechanical load when engine is running.Serious cylinder bore distortion will lead to abnormal wearing of engine,high blow by and oil consumption, even scuffing of cylinder bore, pistonfragmentation. This not only affects the development of engine project, but alsothe repair costs increasing. Customers would also complain.The paper combines finite element calculation with actual measurement toreduce cylinder bore distortion by optimum design and manufacture. It solvesthe failures cause of cylinder bore distortion.Firstly, this paper summarizes the finite element calculation method ofcylinder bore distortion. The paper researched on FEM model and analysisprocess, mechanical load boundary, heat load boundary, operating conditions.According to calculated results and measured data, consider the rated conditionand the maximum gas pressure condition.Secondly, for cylinder bore scuffing of engine, measured the cold clearanceof cylinder, calculated of cylinder bore distortion and dynamic analysis ofpiston components. Optimize cylinder block structure, modified piston skirtprofile, increased the clearance of cylinder and adjust casting process to solvethe scuffing.Third, serious cylinder bore distortion happened with unreasonablestructure and heat treatment. It can lead to high blow by and oil consumption.Optimize cylinder block structure and heat treatment to solve the failure.Through this paper, we solve the practical problems in the development ofChery engine, master the test method and process, finite element analysis,evaluation of cylinder bore distortion.