驱动和结构参数对共轨喷油器喷射特性稳定性的影响

The Influence of the Driving and Structural Parameters on the Stability of Injection Characteristics of Common-rail Injectors

在考虑燃油物性的瞬态性、喷油器不同结构参数以及电磁阀的磁路和驱动策略的基础上,建立电-磁-机械-液力多场耦合的共轨喷油器动态喷射数学模型,并通过不同工况下喷油规律试验数据对模型进行校核,之后,基于该模型对不同影响因素对循环喷油量的影响程度进行了量化分析。分析结果表明:不同参数对循环喷油量的影响程度取决于轨压范围,在轨压小于80MPa的情况下,各参数对循环喷油量的影响程度从大到小依次为喷孔总面积、控制柱塞直径、OZ孔径、OA孔径、针阀最大升程、峰值电压和保持电流;在轨压超过80MPa后,随着压力增大,控制柱塞直径对循环喷油量的影响程度超过喷孔总面积,且随压力的升高而增大,喷孔总面积对循环喷油量的影响程度排在第二位,但压力相关性很小,其他因素的影响程度顺序不变,OZ孔径、OA孔径和针阀升程的影响程度随压力的增大而降低,驱动策略的影响程度最小,且随压力的变化基本维持稳定。

In this article,by considering the fuel properties,structural parameters,the magnetic circuit,and the driving strategy,a mathematic model for mechanical–electromagnetic–hydraulic coupling is developed for a common-rail injector.The calculation results favorably match the experimental data and prove the validity of the mathematical model.Based on this model,numerical analysis results show that the rail pressure determines the influence degree of the parameters.For rail pressures below 80 MPa,the most significant influencing parameter is the nozzle hole area,followed by the diameter of the control plunger,the inlet orifice(OZ)diameter,the outlet orifice(OA)diameter,the maximum displacement of the needle,the boost voltage,and the hold current.For pressures exceed 80 MPa,the influence degree of the diameter of the control plunger is most significant,and the rank of influence degrees of the other parameters do not change.With increases in rail pressure,the influence degree of the diameter of the control plunger increases,while the degrees of influence of the OZ diameter,the OA diameter,and the maximum needle displacement reduce.The influence degree of the nozzle hole area,the boost voltage and hold current show a weak pressure dependence.