基于轨压瞬态压力降的高压共轨燃油喷射系统喷油量校正策略

Fuel Injection Quantity Correction Strategy for High-pressure Common Rail Fuel System Based on Transient Rail Pressure Drop

试验研究了喷油量、发动机转速以及共轨压力对高压共轨燃油喷射系统轨压瞬态压力降低幅值变化规律的影响。研究结果表明,瞬态轨压在喷油器启喷后会明显下降,且降低幅值与喷油量、发动机转速以及共轨压力均密切相关。基于喷油量、发动机转速以及共轨压力对轨压瞬态压力下降现象的影响规律,制订了循环喷油量的校正策略,试验结果表明,该控制策略可以有效提升循环喷油量的均匀性并相应地大幅改善发动机的循环变动。

Influences of fuel injection quantity, engine speed and common rail pressure on transient rail pressure drop of high- pressure common rail fuel system were researched through the experiment. The research result shows that the transient rail pressure has an obvious drop after the injection starts and the drop amplitude has close relationship with fuel injection quantity, engine speed and common rail pressure. Based on the influences of fuel injection quantity, engine speed and common rail pres- sure on transient rail pressure drop, the correction strategy of cycle fuel injection is established. The further experiment shows that the strategy can improve the uniformity of cycle fuel injection and the cycle-to-cycle variation to a great extent.