Simulation Analysis Of Crankshaft System In Internal Combustion Engine Based On Multi-body System Dynamics

With the car quantity rising sharply, under the pressure of severe market competition andincreasingly stringent environmental regulations, the requirements on the vibration and noisequality are increasing in internal combustion engine industry. The comprehensive predictionand the control of internal combustion engine vibration magnitude and noise level in the stageof research and development has become an important goal of internal combustion engineindustry. Running incentive of crankshaft system is an important form of internal incentive ofthe engines＇vibration and noise. The research on the dynamic characteristics is the premisefoundation of the engines＇vibration and noise control.For a certain V8 diesel engine,this paper carries out dynamic characteristics researches ofcrankshaft system under the condition of oil film dynamic pressure lubrication of the mainbearing, by using virtual prototype simulation technology of multi-body systemdynamics .Specific contents are as follows:1) For a certain V8 diesel engine including angle of 90°,by using 3-D modelingsoftware PRO / E, the parametric model of crank and connecting rod mechanism (crankshaft,connecting rod assembly, piston assembly, flywheel etc) is established and assemblied.2) By using multi-body dynamics analysis software ADAMS / Engine, this paper carriesout the multi rigid body system dynamics analysis researches and gets the kinetic parametersof crank and connecting rod mechanism, including the load of main bearing and the flankingforce of the piston impact on the cylinder wall,ect.3) By using the software Pro / E and ADAMS / Autoflex module, the flexible-bodydynamics simulation model of crank and connecting rod mechanism is established under thecondition of flexible crankshaft ,thorugh the simulation, this paper gets the relevant kinetic results, then analies and compares of influence on dynamics simulation result of crank andconnecting rod mechanism based on the rigid-flexible two different modeling methods .4) Oil film lubrication dynamics model of crank and connecting rod mechanism isestablished by loading the oil film on the main bearing.Through the dynamics simulation,thispaper gets a series of dynamic results under the conditions of the multi-body system with oilfilm load coupling, then compares and analies of the oil film load impact on the dynamicsimulation results.This paper indicates that: multi-body system analysis model is more close to the realworking condition of crank and connecting rod mechanism and provide more real excitationfor the follow-up of the vibration and noise analysis by considering the flexible of body andoil film lubrication conditions.