摩托车发动机切换凸轮型线可变配气正时机构研究

A Research on a Variable Valve Timing Mechanism with Switching Cam for Motorcycle Engine

在摩托车发动机单顶置凸轮轴配气正时机构的结构形式基础上,研制一种可切换凸轮型线的VVT机构,具有2套可切换的进气配气正时参数。对VVT机构调整摩托车发动机热力循环过程和运行参数进行分析。结合JH125摩托车发动机所进行的研究表明:该机构结构简单、对原机结构改动小、成本低,能够实现配气相位的可变控制,有效改善发动机性能,可广泛应用于中小排量摩托车发动机。

A variable valve timing（VVT） mechanism with switching cam is developed on a motorcycle engine with single overhead camshaft. The VVT mechanism has two sets of switchable intake valve timing parameter. The adjustment on thermodynamic cycle process and operation parameters of motorcycle engine by VVT mechanism is analyzed. The study with jH125 motorcycle engine shows that the VVT mechanism is simple in structure, has low cost, requiring less modification, and is able to realize variable control ＇on valve timing and effectively improve engine performance. All of these make it possible to be applied to motorcycle engines with small and medium displacements.