【作者】 陈宏；

【导师】 鲁统利； 杨晓；

【作者基本信息】 上海交通大学 ， 车辆工程（专业学位）， 2016， 硕士

【摘要】 前置后驱车辆的传动系工作时由于存在多个自由度,传动系扭转振动通过结构传递和空气传递引起车身薄板共振、齿轮敲击等振动噪声问题一直是车辆NVH提升的重点关注问题,带减振机构的离合器从动盘作为传动系关键的减振部件,合理的参数匹配与调校对改善传动系振动噪声问题贡献较大。本文以某国产经济型前置后驱MPV车辆作为研究对象,针对主观评价的车内噪声问题,对传动系扭振进行建模分析。基于建立的13自由度传动系扭振模型,以车辆3挡、5挡加速工况为代表,分析系统自由振动固有频率与振型,结果表明传动系2阶、3阶固有频率正好落在发动机第2、第3、第4谐次频率范围内,其中发动机2阶、4阶为发动机主谐次,传动系存在共振风险。同时利用模型进行传动系强迫振动分析,分析表明3挡全油门加速工况下,发动机转速为1916r/min时系统存在共振,其频率正好对应传动系2阶固有频率,5挡工况下传动系没有共振风险。最后通过Rotec扭振测试系统实测系统扭振情况,对比分析测量结果和软件仿真结果,验证模型的可靠性。本文接着讨论减振器刚度、阻尼变化对传动系强迫振动的影响趋势,对比了减振器3组不同刚度和3组不同阻尼组合的方案对传动系强迫振动的影响,结果显示在阻尼不变的情况下增加扭转刚度值减振器减振效果变差且对应的共振转速也会上升,而在刚度不变的情况下增加阻尼值则会降低传动系扭振峰值,但过度增加阻尼将会影响传动系扭振在高速区间的表现。最后根据仿真分析对离合器减振器提出优化方向,介绍大转角从动盘的优化改进方案,再利用模型仿真和实车测试验证措施的贡献,为传统离合器减振系统的设计提供一定参考价值。更多还原

【Abstract】 Drive line system of FR vehicle is working with multi degree of freedom,torsional vibration transmit through the structure and air then cause body panel vibration,gearbox rattle problem and so on,it’s the main problem of vehicle NVH.Clutch torsional vibration damper as an important damping parts of transmission system,it play an important role by reasonable parameters matching and calibration to improve the NVH problems of drive line.This paper taking a economical FR MPV vehicle as the research object,in view of the subjective evaluation of the interior noise problem,a torsional vibration model of the drive line was built for analysis.Based on the mathematical models with 13 degrees of freedom,and taking gear 3 and gear 5 WOT working condition for example,the natural frequency of free vibration and vibration mode of system was analysed,the results show that the 2,3 order natural frequency of system are close to the 2,3,4 order frequency of engine,the 2,4 order frequency of engine are the main order,there is a resonance risk in drive line.Model was also used to take forced vibration analysis,the analysis shows that in gear 3 WOT condition,the drive line system resonance when the engine speed is 1916 RPM,the frequency which corresponds to the 2 order natural frequency of drive line,and in condition of gear 5 WOT there is no risk of resonance.At last,the vibration data was collected by Rotec torsional vibration analysis system,and compare the measurement results with the model simulation results,verify the accuracy of the model analysis.Then the influence of changed clutch parameter by forced vibration was discussed,and compared the influence by nine groups of different stiffness and damping of clutch by forced vibration,the results showed that under the increase of stiffness but with the same damping value,the damping effect of clutch become worse and the corresponding resonance speed of system also increase.But in the case of constant stiffness values and increase the damping value will reduce the torsion vibration peak of drive line,but excessive increased of damping value will influence the performance of torsional vibration in high speed range.At last,the improving direction of clutch was got by simulation analysis,and introduce the big angle of platen as improvement scheme,then validates the effectiveness of the measures by simulation and real vehicle test comparation,provides a certain reference value for the traditional clutch design.更多还原