内燃机配气机构噪声控制

为降低内燃机配气机构振动噪声,以某125型摩托车发动机配气机构为研究对象,利用高次多项式对凸轮型线进行优化设计.配气机构多体动力学仿真表明:优化后的配气机构没有出现"飞脱"和"反跳"现象,进、排气气门丰满程度有所增加,在各个转速下,气门的最大振动加速度降低了65%左右,气门与摇臂的撞击力有所降低,且气门与气门座间的撞击力明显下降.在此基础上,制作了凸轮样件并对优化前后配气机构进行声功率测试试验.结果表明:在测量转速范围内声功率级均降低1.5～2dB.

Control on valve train noise of internal combustion engine

An optimization design for the cam profile of the valve train system in the 125-type moor engine is present using the high order polynomial in order to decrease the vibration and noise of the valve train system.The multi-body dynamic simulation for the optimized valve train system shows that the"jump-fee","rebound"is avoided,the plentiful degree of the inlet and outlet valve is enhanced.the maximum acceleration of the valve vibration decreased by 65%.the impact force between the valve and rocker is reduced and the impact force between the valve and the valve seat is reduced markedly.Base on this,the sample of the cam is made and noise level of the valve train system before and after the optimization is tested.And result shows that the sound power level decreases by 1.5～2 dB in the measured rotate speed range.