基于特征参数的柴油机喷油正时状态诊断

Diagnosis of working conditions of fuel injection timing in diesel engines based on feature

燃油供给系统是柴油机最重要的子系统之一,它的性能的好坏直接影响到混合气的形成过程和发动机的动力性、起动性、噪声及环境污染等性能。柴油机喷油正时与否直接决定供油系统能否正常工作,针对柴油机在不同喷油状态下的压力波动变化,采用外卡测量并对压力信号进行预处理和二次处理,从中提取诊断特征值,从而给出不同工况的诊断结果,由于油压波形信号重复性较好,各缸同一工作段的某些幅域参数变化不大,因此,幅域参数作为诊断供油系统喷油状态的方法是可行的、有效的。

The fuel supplies system is one of the most important sub-systems of diesel engine, whose capability directly affects the engender of air admixture, engine＇ s dynamical quality ,jump-start quality, noise and pollution of the environment etc. The fuel injection timing in diesel engines directly decides whether the fuel supplies system can normal work. Aimed at the different fuel injection condition in the different pressure, the external pipe oil signal measuring method and proceed pretreatment and second signal disposition are applied,in which pick-up the diagnosis eigenvalue , thereby different diagnosis result of different work condition is give, because of the fuel pressure wave signal＇ s repetition perfect, the characteristics of amplitude at each urn of the same work sect changes small, therefore, the characteristics of amplitude applied to diagnose the fuel supplies system of diesel engine is effective and feasible.