某多用途货车传动系扭振试验分析与优化

某多用途货车加速行驶时,在发动机转速1200 r/min~1500 r/min范围内,传动系出现明显振动,影响整车NVH品质。针对此问题在传动系关键节点处加装传感器,对车辆6个前进挡在加速工况下进行扭振测试,由数据处理获得传动系各部位的角加速度振幅随发动机转速变化的关系。分析获得各部位振动的主要阶次,确定发动机2阶激励是引起扭振的主要原因。通过对车辆扭振特性的分析,确定传动轴和后桥是扭振的主要部位。为解决传动系统扭振问题,将传动系简化成12个集中质量的扭转振动系统模型,分析离合器扭转减振器主减振级扭转刚度和阻尼力矩参数对传动系扭振的影响规律。提出改善传动系扭振解决方案,并确定优化后扭转减振器参数,测试结果表明扭振得到明显改善。

Torsional Vibration Test Analysis and Optimization of the Transmission System of a Multi-purpose Truck

When a multi-purpose truck is accelerating,its transmission system has obvious vibration in the range of 1200-1500 rpm of engine speed,which affects the NVH quality of the whole truck.Therefore,the sensor is installed at the key node of the powertrain,and the torsional vibration test is carried out for the six forward gears of the truck under the accelerating condition.The relationship between the angular displacement amplitude of each part of the powertrain and the rotational speed of the engine is obtained by data processing.The main order of vibration of each part of the powertrain is obtained.It is determined that the second-order excitation of the engine is the main cause of torsional vibration and the transmission shaft and the rear axle are the main parts of the torsional vibration through the analysis of the torsional vibration characteristics of the vehicle.In order to solve the torsional vibration problem,the transmission system is simplified to a model of the torsional vibration system with 12 concentrated masses.The influence of the torsional stiffness and damping torque parameters of the main vibration stage of the torsional damper on the torsional vibration of the transmission system is analyzed.A scheme to improve the torsional vibration of the transmission system is proposed,and the parameters of the torsion damper after the optimization are determined.The results show that the torsional vibration is significantly improved.