主承力结构对柴油机振声响应影响规律的研究

Researches on the Influence of Primary Load-carry Structures on Noise and Vibration of Diesel Engines

建立某12V型柴油机的有限元模型,进行整机振动频响计算,并结合AML方法建立该柴油机的声辐射预测模型。在此基础上,开展主承力结构不同设计参数方案下的内燃机整机振声响应计算,从而确定影响内燃机振声响应的主承力结构关键设计要素:主轴承座-盖宽度、机体箱体内侧板位置及机体箱体外侧板厚度,并对上述设计参数进行关于内燃机整机声功率级的响应面分析。通过响应面分析的结果,获得了该柴油机主承力结构的最优设计方案,对比优化前后整机声功率级值,主承力结构优化后整机声功率级值减小了1.87 d B(A),即优化后声功率比原始结构下声功率减小了1/3,优化效果显著。

The finite element model of a 12 V diesel engine is established and the frequency response of the whole machine is calculated. Combined with the AML method, the acoustic radiation prediction model of the diesel engine is established. On this basis, the calculation of the vibration response of the internal combustion engine under different design parameters of primary load-carry structures is carried out to determine the key design elements of primary load-carry structures that affect the vibration response of the internal combustion engine： the width of the main bearing housing-cap, the position of engine block＇s inner side panel and the thickness of engine block＇s outer side panel. At last, make response surface analysis with these key design elements. According to the results of response surface analysis, the optimum design scheme of primary load-carry structures of diesel engine obtained. Compared with the original diesel engine, the sound power level of the optimal design is 1.87 d B（A） lower than the original structure＇s. In other words, the sound power of the diesel engine decreased by one third. The optimization has achieved a notable improvement.