某重卡发动机排气系统结构优化

Structural Optimization of Exhaust System of Heavy Truck Engine

基于考察某重卡排气管可靠性目的,本文利用锤击模态试验方法,对排气系统进行模态计算分析并考察其振动情况。通过加强约束方式,使该排气系统一阶固有频率由91.59Hz提高到发动机额定转速对应的点火激励频率以上,并降低了排气系统的振动,取得了理想的效果。结果表明,通过增强支架约束方法能有效的避免因发动机激励共振引起的故障。

For the purpose of investigating the reliability of the exhaust pipe of a heavy truck,this paper uses the hammering modal test method to calculate and analyze the modal of the exhaust system and investigate its vibration.The first order natural frequency of the exhaust system is increased from 91.59Hz to more than the ignition excitation frequency corresponding to the rated engine speed by strengthening the restraint mode,and the vibration of the exhaust system is reduced,and the effect is ideal.The results show that the fault caused by engine excitation resonance can be effectively avoided by strengthening the bracket constraint method.