液压可变配气系统凸轮优化设计

液压可变配气系统是一种新型可变气门技术及系统,调节后的气门升程曲线变化趋势与发动机不同转速时最优气门升程曲线变化趋势相同,对进一步提升发动机中低转速的有效转矩具有重要意义。针对系统的工作特点,提出了分段地针对性凸轮设计方法,使凸轮既能满足充气效率、接触应力、工作平稳等基本要求,又能满足气门调节匹配和油液压缩补偿的特殊设计要求。通过对配气凸轮进行优化,不同转速时的气门实际相位与最优相位接近,气门实际升程均大于最优升程,有利于提高换气效率,实验结果较好地满足了发动机最优配气参数要求。

Optimal Design of Cam Profile for a Hydraulic Variable Valve System

The hydraulic variable valve system is a new type of variable valve technology and system. The change trend of valve curve after adjusting is the same as that of the optimal valve curve at different engine speeds,which is of great significance to further improve the effective torque of the engine at medium and low speed.According to the working characteristics of the system,the design method of cam is put forward,which can not only meet the ?basic requirements of inflation efficiency,contact stress and smooth operation,etc. It can also meet the special design requirements of valve adjustment matching and oil compression compensation.By optimizing the valve cam,the actual phase of the valve is close to the optimal phase at different rotational speeds,and the actual lift of the valve is larger than the optimal lift,which is helpful to improve the efficiency of air exchange. The experimental results meet the requirements of the optimal engine valve parameters.