柴油机高压共轨系统预喷射对主喷油量的影响

Effect of Pilot Injection on Main Injection Mass for Engine High Pressure Common Rail System

在能够进多段喷射的高压共轨系统中,连续测量两段喷射的喷油量与单独测量预喷射和主喷射喷油量时结果不同:预喷射喷油量基本不变,而主喷射喷油量呈现有规律的变化。使用单次喷射仪研究了预喷射对主喷射油量的影响。结果表明:预喷射引起共轨管内压力波动,主喷射靠近压力波动的波峰喷油量增加,靠近波谷喷油量减少,预喷射喷油持续越长,压力波动幅值越大,主喷射油量变化越剧烈;预喷射与主喷射之间的时间间隔对压力波动没有影响,但改变了主喷射与共轨管压力波动相位的对应关系。

The influence of pilot injection on main injection mass was studied by a single injection meter in this paper.The experiment results showed: the main injection fuel mass is influenced by the quantity of pilot injection and the interval between pilot and main injection when a multi-pilot injection is carried out.The fluctuation of pressure in common rail which was induced by pilot injection is the reason of main injection fuel mass variation.The quantity of main injection increases when it locates at wave crest,and decreases when it locates at wave trough.The fluctuation in common rail increases while the pilot injection duration increases and influences the variation of main injection fuel mass finally.There is no relationship between the value of pressure fluctuation and the interval between pilot injection and main injection.The interval changes the phase between main injection and pressure wave in common rail.