【摘要】 改变195柴油机的转矩、转速及供油时刻,测量分析各工况的缸盖振动加速度信号,分析结果表明,同样转速时,缸盖振动加速度时域最大波动量及2kHz以下各频带能量与缸内燃烧状况相对应;当转速发生改变时,加速度信号时域最大波动量及各频带能量与缸内燃烧状况间无对应关系。建立有限元分析模型,研究缸盖联接螺栓预紧力及材料刚度对缸盖振动加速度信号的影响规律,结果表明当材料的杨氏模量或联接螺栓预紧力减小时,系统的固有频率降低,使得缸盖振动加速度信号时域最大波动量及2kHz以下各频带能量呈增大的趋势。更多还原

【Abstract】 Cylinder head vibration acceleration signals were measured from a 195-type diesel engine by changing its torque,rotating speed and injection timing.The signals were analyzed and the results showed that the amplitude of the maximum fluctuation and the frequency components under 2kHz of the acceleration are related with the combustion status under the same rotating speed,while both of them have no the correspongding relation during the rotating speed varying.The influences of pretightening forces and material stiffness were studied using a finite element model of the engine.Results showed that the natural frequencies of the engine drop with decrease in stiffness and pretightening forces,meanwhile the amplitude of the maximum fluctuation and the frequency components under 2kHz of the vibration acceleration raise.更多还原