【作者】 张健；

【导师】 杨啟梁；

【作者基本信息】 武汉科技大学 ， 车辆工程， 2013， 硕士

【摘要】 发动机动力总成是汽车主要的噪声源和振动源之一，而动力总成悬置系统是减少、隔离发动机的振动向车身传递的最主要途径，它是由连接动力总成和车架/车身的数个悬置组成的隔振系统。一个良好的发动机动力总成悬置系统，不仅可以延长发动机和其它部件的使用寿命，更重要的是可以改善汽车的乘坐舒适性,它是解决内燃机整机振动最为有效的办法。由于传统的橡胶悬置元件结构简单、价格低廉、使用寿命长、性能稳定等诸多优点，在隔离发动机的振动上发挥了重要的隔振作用，因此至今仍被广泛采用。本文针对某汽车公司自主研发的一款轻型商务客车的隔振性能进行了较深入的研究，以橡胶悬置为研究对象，对其隔振原理、数学模型的建立进行了较深入的研究。通过已测得的动力总成惯性参数和计算的有关车身建模参数建立了六自由度和十二自由度的动力总成悬置系统ADAMS动力学模型，并用MATLAB软件通过编程验证了ADAMS模型的正确性。在以往的关于动力总成悬置系统研究中，试验与仿真往往是分开的，前者只是单纯的验证后者的正确性，很少有将二者结合起来来研究发动机怠速激励下的悬置系统的隔振性能。本文通过试验与理论计算相结合提出了比较实际有效的确定发动机怠速激励的方法，并用该激励对已建立的动力总成悬置系统ADAMS动力学模型悬置软垫的刚度进行了不同目标函数的优化，并对该悬置系统怠速隔振率进行了仿真计算与分析。经过悬置软垫的试制和装车，对车辆怠速隔振率、座椅振动和后视镜的振动进行了实车试验，结果表明该车具有较好的NVH性能，同时，动力总成悬置系统怠速隔振率的仿真与试验结果能较好地吻合。更多还原

【Abstract】 Powertrain is one of the most principal noise sources and vibration sources of automobiles,while the mounting system which is composed of several mounting cushions connecting thepowertrain and frame of bus (or automobile body) is the most primary approach to decrease andisolate the transmission of vibration from engine to the automobile body. A reasonable enginemounting system can not only extend the life of engine and other components, but the mostimportant is that it can improve the ride comfort. It is the most effective way to solve the enginevibration．Traditional rubber engine mounting system playing an important part in isolating thevibration from engine possesses advantages of simple construction, low cost, long service life,stable performance, and so on, so it is used widely nowadays. This paper makes a comprehensivestudy of the performance of vibration isolation of a light business bus which is researched anddeveloped independently by a motor corporation. It analyses the working principle of vibrationisolation and addresses in detail the modeling mathematical methods of engine rubber enginemount. Six and twelve degrees of freedom ADAMS dynamical model of powertrain mountingsystem are built after the inertial parameter of the powertrain is measured and the parameter tobuild model of the automobile body is calculated, then the accuracy of the models are verified bythe MATLAB program.In the previous research about the powertrain mounting system，experiment and simulationare separated, and the purpose of the former is only to verify the accuracy of the latter，but rarelyto combine them to study of the performance of vibration isolation of mounting system under theengine idle excitation. This paper presents a practical and effective method to determine engineidle excitation which combines test and theoretical calculation, and then the stiffness of themounting cushions of the ADAMS dynamical model of powertrain mounting system isoptimized from the different objective functions and idle vibration isolation rate of thepowertrain mounting system is simulated, calculated and analysed with this excitation. The bus’sidle vibration isolation rate, the level of the vibration of seats and rearview mirrors are test,whose test result shows the bus possesses a good performance of NVH, besides, the idlesimulation results of powertrain mounting system and test results agree well.更多还原