【作者】 杨俊杰；

【导师】 龚宪生；

【作者基本信息】 重庆大学 ， 机械设计及理论， 2011， 硕士

【摘要】 扭转振动是汽车动力传动系统的主要振动形式,它影响着汽车的使用性能和乘坐的舒适性。传统的从动盘式扭振减振器(Clutch Torsional Damper, CTD)虽对控制扭振及其噪声起着积极作用,但实践证明,该方法存在着严重的不足和缺点。诞生于上世纪八十年代中期的双质量飞轮减振器(Dual Mass Flywheel, DMF)由于克服了CTD的不足,有效地降低传动系扭转振动,使得汽车减振降噪技术发生了质的飞跃。然而,由于DMF的设计要求高,加工难度大,技术性能指标严格,目前在国内仍停留在样件制作阶段,还难以普及。鉴于此,某企业开发了一种减振效果明显优于CTD,但是略差于DMF的新型扭振减振器(New Type of Vibrational Damper,简称NVD),其结构简单、易于加工制造。本文以NVD为研究对象,主要对其结构和减振性能进行研究:(1)NVD自身振动特性的计算和分析;(2)固有特性分析以及在各种工况下的静、动强度研究;(3)在汽车动力传动系中的振动特性分析;(4)在轴系中减振效果的仿真优化研究。首先介绍了扭振减振器的发展概况和相关研究的国内外现状,特别是DMF的产生、发展以及减振原理等,并提出了论文研究的目的及意义。其次,对NVD的结构特点、工作原理进行了详细的分析,并就其自身结构建立力学模型和数学模型,从而对其振动特性进行了研究。第三,借助于相关有限元理论和工具,进行固有特性分析,即模态分析。然后,根据NVD所匹配的汽车在极限工况(突然起步和紧急制动)、怠速和行驶工况下的所受载荷情况,进行相应的静、动态强度分析,分析结果表明,除铆钉不满足强度外,其它零部件均满足强度要求,并提出了两种改善强度的合理方法。第四,将NVD置于汽车轴系中,在动力学软件ADAMS中建立轴系扭振模型的虚拟样机,通过动力学仿真分析,得到各参数变量对减振器减振效果的影响。最后,对安装有NVD的轴系虚拟样机进行在怠速下的仿真优化,分别以两种不同目标函数作为优化目标,然后得到不同的优化参数,通过对比研究两组参数,得到合理的最优值,并对最优阻尼值进行共振验算,结果表明,最优参数能够有效衰减共振时的扭振幅值。另外,也对传动系在不同减振效果下所对应变量参数的取值情况进行了研究。新型扭振减振器具有良好的发展空间和前景,因此,对装备有NVD或类似扭振减振器的整车动力传动系统的结构和扭振特性进行分析和仿真研究,具有重要的指导价值和实际意义。更多还原

【Abstract】 Torsional vibration is an important component vibration in Automobile Powertrain, which plays a very important part in performance and ride comfort. Although traditional Clutch Torsional Damper (CTD) has a positive effect on controlling torsional vibration and noises, it has been proved that CTD system has serious disadvantages. Dual Mass Flywheel (DMF) was invented in 1980s. As it can effectively overcome the shortcomings of CTD and reduce the torsional vibration of transmission agent, the automotive damping and noise reduction techniques was greatly enhanced. However, because of its high design demand and severe performance requirements and hard to machine, DMF is still stay to the stage of sample manufacturing at home presently. Based on this fact, a corporation developed a New Torsional Vibration Damper (NVD) which is simple in construction and easy to manufacture. Experimental research shows that NVD is much better than CTD in damping effects, but weaker than DMF slightly.This dissertation studies the construction and damping property of this new type of torsional vibration damper, mainly includes 4 aspects: (1) Vibration Characteristic and output response were calculated and analyzed; (2) Natural characteristics and static and dynamic strength in different working conditions were studied; (3) The analysis of vibration Characteristics in Automobile Powertrain were carried out; (4) The damping effect in the vehicle drivetrain was simulated and each important parameter of the damper was optimized with ADAMS software.First of all, the dissertation introduces the general development of torsional vibration damper and the domestic and international developments of related research, especially includes the advent, development and damping principle of DMF, etc. Meanwhile, the study content and its research purpose and meaning were illustrated.Then, the structural characteristics and working principle of NVD were analyzed in detail, and the mathematical and mechanical models were established based on its structure. After that the vibration characteristics of this damper was studied.Moreover, modal analysis of this new type of damper was carried out with the finite element theory and tools. Also, static and dynamic structural strength, stress and strain under static and dynmic load were calculated and analyzed. Where, the static load is working load limit (includes sudden starting and emergency braking) and the dynamic load includes real load of idle speed and running condition. The analytical results revealed that the part of rivets can not meet strength requirement under static load and all other parts can meet requirements. Therefore, two reasonable methods were proposed to improve the strength of rivets.Fourthly, the virtual prototype of torsional vibration model was built in the kinetic software of ADAMS after NVD was placed in the Automobile Powertrain. Then through dynamics simulation analysis, the influence of each parameter variables on damping effect of NVD was obtained.Finally, the virtual prototype of shafting which is equipped with NVD was simulated and optimized under idle speed. The optimization method is that two different target function was made with the minimum of function value as optimization objective, respectively. Then different optimal parameters were obtained, by comprehensive studying those two groups of parameters, reasonable optimal value was got, and the resonance checking of the optimum damping coefficient was carried out. The results indicated that the resonance amplitude can be effectively dampened by the effect of optimal parameters. Otherwise, how to get suitable values on each parameter variables in powertrain under different damping effect was studied.New torsional vibration damper has a huge developing space and very bright developing prospects. Accordingly, it has great guiding value and practical significance to research on the analysis and simulation of the torsional vibration characteristics of Automobile Powertrain which is equipped with NVD or other similar torsional vibration dampers.更多还原