发动机启停时动力总成悬置系统的设计方法研究

摘要

This paper put forward a dynamic response evaluation index and a calculation method of the powertrain mounting system key on/off condition based on the analysis of the excitation force.Considering that increasing the damping of the mounting system can reduce the vibration when the engine key on/off,a semi-active damping strut was designed and manufactured.The semi-active damping strut provides the mounting system with a large damping,and when the engine is working normally,the semi-active damping strut provides small damping to isolate the high frequency vibration of the engine.At the same time,the influence of different engine starting torque on powertrain vibration was analyzed.Under the condition of large starting torque excitation,the changes of longitudinal acceleration,impact degree,mount dynamic supporting force and VDV of the powertrain were compared after the semi-active damping strut was introduced.Studies have shown that the use of damping strut can improve key on/off vibration to a large extent and save oil as well.%在对发动机启停时激励源分析的基础上,提出了启停时动力总成悬置系统的动态响应评价指标和计算方法.考虑增加悬置系统的阻尼可以减小发动机启停时的振动,设计并制造了一款半主动阻尼拉杆,其特点是:当发动机启动时,半主动阻尼拉杆给悬置系统提供很大的阻尼,而当发动机正常工作时,半主动阻尼拉杆提供小阻尼,隔离发动机的高频振动.同时分析了不同的发动机的启动扭矩对动力总成振动的影响.在较大的启动扭矩激励下,对比了添加半主动阻尼拉杆后,通电和不通电时动力总成的纵向加速度,冲击度,悬置动态支反力和VDV四个指标的变化.研究表明添加半主动阻尼拉杆可以很大程度改善汽车启停时的振动,达到节油的目的.