Kazuhide Ohta

Investigation of piston slap induced vibration of IC engine considering the coupled vibration of connecting rod, crankshaft and engine block

Piston slap is a major cause of the complex transient vibration response related to the impact excitation inside the engine. In the conventional analytical model of piston slap, the coupled vibration of piston and cylinder liner was taken into consideration only. In order to estimate the piston slap induced vibration of IC engine accurately, a theoretical model of piston slap which considering the movement and coupled vibration of piston, connecting rod, crankshaft and engine block was proposed. Based on this model, the piston slap and vibration response of some type of 3.5 L diesel engine were predicted. Then the comparison of rotate angle of piston, impact force induced by piston slap, torsional vibration of crankshaft, reaction force acting on main bearing and the vibration response of engine block between the present method and conventional method have been discussed in details. Research results revealed that the coupled vibration takes seriously influence on piston slap and the piston slap also influences the characteristic of crankshaft torsional vibration, reaction force at main bearing and vibration response of engine block inverse.