道路试验下某重型商用车驾驶室啸叫声源定位

Noise source localization of a heavy commercial vehicle cab under a road test

针对某重型商用车在中低挡加速工况下驾驶室内出现的啸叫噪声问题。首先,对包括发动机、变速箱和中后驱动桥在内的动力传动系统进行了研究,重点分析了变速箱在问题挡位工作时的动力传递路线,明确了问题挡位下参与动力传递的啮合齿轮副。其次,设计整车道路加载试验,在发动机飞轮、驾驶室内、变速箱近场及壳体、中后驱动桥壳体及车架位置布置相应的转速、噪声及振动加速度传感器。对发动机转速进行追踪,采集7挡加速工况下各测点的噪声和振动信号。对试验数据进行处理分析,结果表明,除发动机激励外,驾驶室啸叫噪声主要由28阶和42阶激励引起且后者的影响更为显著。对变速箱主箱和副箱以及中后驱动桥位置的齿轮副进行阶次计算,结果表明,副箱行星齿轮机构中单个行星轮与外齿圈的啮合阶次为14.02阶,其2次和3次谐阶次与驾驶室内的啸叫噪声阶次相对应,定位出了问题出现的根源。最后,针对问题齿轮副,提出了相应的改进措施。

Aiming at the problem of whining noise in the cab of a heavy commercial vehicle in the acceleration condition with a middle and a low gear,the research was conducted.Firstly,the powertrain including an engine,an gearbox and a middle and rear dive axle was studied.The power transmission route of the gearbox in the gear was analyzed,and the meshing gear pair involved in power transmission was defined.Secondly,the road loading test of the whole vehicle was designed.The corresponding speed,noise,and vibration acceleration sensors were arranged in the engine flywheel,cab,gearbox near field and shell,middle and rear drive axle shells,and the frame.The engine speed was tracked,and the noise and vibration signals of each measuring point were collected under 7-gear acceleration condition.The experimental data were processed and analyzed.Results show that,in addition to engine excitation,the cab noise is mainly caused by the excitation of the 28 th order and the 42 th order,and the latter is more significant.The order of the main gearbox,auxiliary gearbox,and the gear pair of middle and rear drive axle was calculated.The results show that the meshing order between the single planetary gear and the outer gear ring in the planetary gear mechanism of the auxiliary gearbox is 14.02,and the second and third harmonic orders are corresponding to the whining noise order in the cab.The root of the problem was located.Finally,the corresponding improvement measures were provided.