【作者】 孙登兴；

【导师】 邓兆祥；

【作者基本信息】 重庆大学 ， 动力机械及工程， 2005， 硕士

【摘要】 设计性能良好的动力总成悬置系统减少动力总成振动向车体的传递,从而降低噪声改善舒适性,这一直是汽车设计者所关心的重要课题。传统的以解耦为目标的优化不涉及到任何响应计算,虽然按照传统的经验,这对降低振动向整车的传递有一定的作用,但是要把振动传递率控制在一个较低的水平,还需要以支承处的响应为目标进行优化。本文以某国产轿车为研究对象,以力传递率最小为目标,从悬置系统的布置方式到悬置系统的隔振性能进行了全面的分析和研究。主要包括以下几个方面的内容:首先,本文探讨了动力总成隔振系统的设计原则和布置型式,建立了悬置系统六自由度的振动模型,从频率的匹配和模态的解耦进行考虑,综合考虑悬置的布置形式和发动机舱的空间限制,确立了悬置系统的初期布置方案。其次,通过对各个影响因素的分析,利用多体动力学软件ADAMS(AutomaticDynamic Analysis of Mechanical System)建立了悬置系统刚体动力学模型。结合本车实际,以力传递率最小为目标,在强迫激励下,对原有悬置的隔振性能进行了评价。通过各个参数对隔振性能影响规律的分析,针对对隔振影响较大的参数,利用二次序列规划法(SQP)进行优化,达到了动反力有效值降低23.6%的良好效果。最后建立完整的整车刚体—柔体耦合动力学模型,更真实地反映了悬置的隔振性能,通过对悬置隔振性能的分析,验证了基于悬置刚体系统动力学模型优化的准确性,指出了提高隔振性能需要努力的方向。总之,本文既探讨了动力总成悬置系统设计的基本思想、原则和要求,又对悬置系统作了比较精确的振动分析,不但改善了本车的振动性能,而且对于其它动力总成悬置系统的设计也具有指导意义和参考价值。更多还原

【Abstract】 It is a crucial task to design an ideal engine mount to isolate the vibration andreduce the noise from power train to frame. Nowadays, research in this field mainlyfocus on the mode’s decouple, but seldom make the minimal response as an objective toimprove the power train’s isolation characteristics. in allusion to present status indomestic, this paper discusses the rule of arrangement and the flexible foundationeffects on dynamic responses of engine-mount systems using computer simulationtechniques. The following subjects are mainly studied.According to the rules that are applied to the power train’s six rigid body modes:frequency targets, couple vs. decoupled modes, etc. The selection and laying out mountlocations and specifying the insulators are completed in the design phase consideringthe package restraints.A six-degrees rigid dynamic model are developed under the ADAMS environment,and then depending on the computed response sensitivities to determine the changes tothe mounting system that will lead to minimum response at user-defined location in thevehicle. Design variables are mount locations, angle and mount stiffnesses, which arechanged until the lowest level of response is found. The isolation characteristics resultsfrom the application of this method is quite better than the traditional ‘rules –of-thumb’methods.Then the flexible foundation’s effects on dynamic responses of engine-mountsystems are considered with the help of computer simulation techniques, the dynamicflexible of the foundation is represent of the foundation is represented by modalinformation from finite element analysis of ANSYS, solving the derived equations,natural frequencies and forced vibration responses can be simulated accurately. And theeffect of engine-mount for the vehicle’s NVH are studied.At the same time, the foundational design procedures and basic requirements ofengine mount system are studied. Accordingly, many designing principle are valuablefor all the other kind of mounting system.更多还原