基于高次多项式动力凸轮型线的配气机构性能分析

为分析高次多项式动力凸轮型线的特性参数对配气机构性能的影响,以某高速汽油机双顶置凸轮轴配气系统为研究对象,基于配气机构运动学和动力学计算理论,建立高次多项式动力凸轮型线的数学模型.在AVL-TYCON中建立运动学和动力学仿真模型,计算并分析丰满因数、正加速脉冲宽度和润滑因数等关键评价指标的变化规律,结果表明：随着各阶幂指数的增大,丰满因数逐渐增加,发动机获得较好的充气性能,但正加速度宽度逐渐减小,配气机构工作平稳性变差.

cam profile; valve train; high order polynomial; kinematics; dynamics; AVL TYCON

To analyze the influence of the characteristic parameters of high order polynomial dynamic cam profile on valve train performance, a high speed gasoline engine with double overhead camshaft valve train is studied. Based on the computation theory of kinematics and dynamics about valve train, the mathematical model of high order polynomial cam profile is established. The simulation models of kinematics and dynamics are built in AVL TYCON, and some key evaluation indicators, such as fullness ratio, positive acceleration pulse length, lubrication factor, and so on, are calculated and analyzed to find out their change law. The results indicate that, with the increase of power exponent of the orders, the fullness ratio increases and the engine gets better volumetric performance, but the positive acceleration pulse length decreases and the valve train gets worse work stability.