Analysis And Research On Characteristics Of Internal Combustion Engine Piston Secondary Motion

Piston secondary motion is a micro motion of piston that occurs during the operation ofreciprocating internal combustion engine. Specifically, it refers to the lateral movement of thepiston and the piston tilting around the piston pin. In the early internal combustion enginestudy, it was not concerned about. With requirements of vibration and noise control improved,piston secondary motion is gradually gained attention. Studies have shown that pistonsecondary motion has certain influence on piston slap and noise, the friction loss of the pistonskirt and the scratch and cavitation of cylinder liner. With further improvement of thevibration and noise control requirements, piston secondary motion characteristics are neededto be researched.Based on the piston dynamics analysis, the piston skirt and ring dynamic lubricationtheory, piston secondary motion characteristics are analyzed systematically in this paper byusing AVL Glide software. During model establishment, factors such as piston elasticdeformation, piston thermal deformation and cylinder liner thermal deformation areconsidered. Specific work contents are as follows:(1) Analysis of the piston dynamics modeling and solving process. In modeling process,factors like piston elastic deformation, piston thermal deformation, cylinder liner thermaldeformation, lubrication and friction of piston skirt and rings are considered.(2) With a certain diesel engine as a research object, related components deformationanalysis theories are investigated when piston load boundary conditions, piston thermalboundary conditions and cylinder thermal boundary conditions are considered. The specificdeformation analysis is conducted later. (3) Based on the piston dynamics model, piston secondary motion characteristics areresearched by using AVL Glide. Piston secondary motion characteristics affected by designparameters, which include cold piston-cylinder clearance, crankshaft offset, piston pin offset,cold piston profile and engine installation angle etc., are mainly inspected. The influence ofthe other parameters, which include piston elastic deformation, piston and cylinder linerthermal deformation and crankshaft rotating speed etc., are also analyzed. The researchconclusions can provide references for the design of the internal combustion engine.