配气机构动变形随转速及气门间隙的变化规律

为确定N次谐波凸轮配气机构动变形响应的精确变化规律,将二阶微分方程全解的解析解法转用于配气机构动力学微分方程。根据这种解法编制了计算机程序,对某发动机配气机构的动变形响应随凸轮轴转速和气门间隙变化的规律进行了仿真计算。计算结果表明,配气机构的动变形规律主要取决于当量气门运动加速度的大小和形状;凸轮轴转速的变化,在气门开启阶段对配气机构的动变形影响较小,在落座阶段对配气机构的动变形影响较大。气门间隙在设计值附近变化不大时,仅在气门开启阶段对配气机构动变形稍有影响。

Dynamic Distortion of Valve Train of Diesel Engine with the Change of Camshaft Speed and Tappet Clearance

This paper gives the exact solution of the Nthdegree harmonic cam valve train vibration differential equation.The accurate dynamic response of distortion was determined.The relation between distortion tracing the speed of camshaft & tappet clearance was analyzed using this method.Based on the analysis of results,it can be concluded that dynamic distortion of valve train is mainly determined by the valve acceleration,and the camshaft speed has more effect to dynamic distortion during the valve lifting period than the valve closing period.The tappet clearance is slightly effective to distortion only during the valve lifting period if it changes not much from designed value.