直列6缸发动机半阶次振动分析及优化

曹精明¹，田金鑫²，翟旭茂^2，3，时保帆¹

1.潍坊内燃机质量检验中心有限公司，山东 潍坊  261061;2.潍柴动力股份有限公司，山东 潍坊  261061;

3.内燃机可靠性国家重点实验室，山东 潍坊  261061

摘要：为降低发动机振动速度，以某直列6缸发动机为研究对象，分析各阶次激励特征，通过整体振动试验、整机模态试验、工作变形分析，确定振动原因，并进行结构优化及试验验证。结果表明：该发动机扭转模态频率较低，并与4.5阶扭转激励耦合，导致发动机机体产生扭转共振，振动速度过高，不满足开发要求；增加机体加强板，可提高扭转模态频率，降低整机振动速度，满足开发要求。

关键词：主阶次；半阶次；振动；扭转模态

Analysis and optimization of half order vibration for an inline 6-cylinder engine

CAO Jingming¹，TIAN Jinxin²，ZHAI Xumao^2,3，SHI Baofan¹

1.Weifang Internal Combustion Engine Quality Inspection Center Co., Ltd., Weifang 261061, China;

2.Weichai Power Co.,Ltd.,Weifang 261061,China; 3.State Key Laboratory of Engine Reliability, Weifang 261061, China

Abstract：In order to reduce the vibration speed and analyze the excitation characteristics of each order of an inline 6 cylinder engine, vibration tests, whole machine modal tests, operational deflection shapes analysis, structural optimization and experimental verification are carried out. The results show that the torsional modal frequency of the engine is relatively low and coupled with a 4.5 order torsional excitation, resulting in torsional resonance of the engine body and excessive vibration speed, which could not meet the development requirements.Increasing the body reinforcement plate could increase the torsional modal frequency, reduce the overall vibration speed, and meet development requirements.

Keywords:main order; half order; vibration; torsion modal