供油压力对可变气门附加升程下降阶段的影响研究

Study on the Influence of Oil Supply Pressure on the Stage of Variable Valve Additional Lift

基于一个电液可变气门试验台架,研究供油压力对可变气门附加升程下降阶段的影响,用a、b、c、d四个特征点将附加升程下降阶段分为ab、bc和cd三个特征段,并提出评价参数加以评价和描述。研究表明,供油压力对泄油过程的自由下降区影响较小;a、b征点的相位随供油压力增大而提前,c点相位不随供油压力变化,d点的相位随供油压力增大而滞后。供油压力越大,ab段的持续时间越短,bc、cd段持续时间越长,ab、cd段附加升程平均变化率随供油压力增大而增大。

Based on an electro-hydraulic variable valve test bench,this paper studies the influence of oil supply pressure on the stage of variable valve additional lift.The four characteristic points a,b,c and d are used to divide the additional lift down stage into three feature segments ab,bc and cd,and put evaluation parameters to evaluate and describe it.Research shows that the oil supply pressure has less influence on the free fall zone of the oil drainage process.The phase of the feature point a and the feature point b are advanced as the oil supply pressure increases.The phase of the feature point c does not change with the oil supply pressure,and the phase of the feature point d lags with the increase of the oil supply pressure.The greater the oil supply pressure,the shorter the duration of the feature segment ab,and the longer the duration of the feature segment bc and the feature segment cd.The average lift rate of the additional lift of the feature segment ab and the feature segment cd increases as the oil supply pressure increases.