基于高次多项式的高速汽油机顶置凸轮特性

针对高速汽油机双顶置凸轮轴设计，建立了高次多项动力凸轮特性研究的数学模型，给出了相关系数的计算表达式．以进气凸轮的设计为例，计算获得了高次多项式动力凸轮型线，并研究了高次多项动力凸轮中不同幂指数对凸轮特性的影响．随着各阶幂指数的增大，凸轮型线的丰满系数和最大正加速度逐渐变大，而最大速度则逐渐变小．最后采用多自由度模型计算了凸轮经动力修正后的运动学及动力学特性．结果表明，采用高次多项式动力凸轮用于高速汽油机凸轮设计，能够获得相对平稳的气门运动特性．

Research of overhead cam characteristic based high order polynomial in high speed-gasoline engine

The mathematics modeling of high order polynomial cam characteristic is built. The calculated expression of correlation coefficient is presented. A dynamic cam profile of high order polynomial is obtained. The influences of differed exponent are studied in dynamic camshaft of high order polynomial. With the increase of the exponent, the fullness ratio and the maximum acceleration of the valve life curve are increasing, and the maximum velocity is decreasing. Furthermore, using more freedom modeling, the cam characteristic of kinematics and The research results reveal that comparative valve dynamics are calculated after dynamic improving. balanced movement characteristic can obtain using high order polynomial dynamic cam in high speed gasoline engine.