高压共轨喷油系统循环喷油量波动研究

Investigation on the cycle fuel injection quantity fluctuation of the high pressure common rail system

针对系统参数对高压共轨喷油系统循环喷油量稳定性的影响机理及变化规律,在AMESim仿真平台上建立了高压共轨喷油系统的数值仿真模型,通过仿真分析研究了回油压力、电磁阀复位力、控制阀杆升程、出油孔直径、进油孔直径、针阀升程、针阀预紧力和喷油器流量系数在全工况平面内所引起的循环喷油量波动变化规律,得出系统参数对循环喷油量波动的影响在小喷油脉宽下更为明显.结果表明,回油压力、控制阀杆升程、出油孔直径、进油孔直径、针阀升程和喷油器流量系数为影响循环喷油量波动的关键系统参数.该研究可为优化高压共轨喷油系统参数、提高系统工作一致性和稳定性提供理论借鉴.

A numerical simulation model of high pressure common rail （HPCR） fuel injection system was estab- lished on AMEsim platform with the purpose of analyzing the influence mechanism and variation law of cycle fuel injection quantity fluctuation （CFIQF） in entire operation conditions （EOC） caused by parameters of the HPCR system. Based on the results obtained from HPCR test bench the numerical model accuracy was validated. The in- fluence on CFIQF caused by the variations of different characteristic parameters in EOC was analyzed. These pa- rameters include fuel return pressure, electromagnetic valve reset force, control valve lift, fuel outlet orifice diame- ter, fuel inlet orifice diameter, injector needle lift, injector needle pretightening force, and injector flow coeffi- cient. Analysis results show that the impact of system parameters on CFIQFs is apparent when the engine is working in small injection pulse width operation conditions. The fuel return pressure, control valve lift, fuel outlet orifice diameter, fuel inlet orifice diameter, injector needle lift and injector flow coefficient are the key influence parame- ters of CFIQ of the HPCR system. The research results can provide important theoretical guidance for optimizing the parameters and improving the consistency and stability of the HPCR system.