Abstract: The fluctuation of the injection quantity on the diesel engine affects the performance of the power and the characteristics of the emission of the engine. In order to study the laws of the influence and the mechanisms of the fluctuation on the cycle fuel injection, this paper analyzes the key design parameters and control parameters of the combined pump based on the electronic unit pump, combined with the methods of the theoretical analysis and the numerical modeling. The results show that the consistencies of the peak pressure and the injection quantity increase with the increase of the supply oil pressure and the diameters of the main and secondary oil passages of the combined pump. The influence tends to be consistent and there is an point of the inflection. When the supply pressure of the low oil passages is greater than 6 bar, the diameter of the main oil passage is greater than 8 mm, and the diameter of the secondary oil passage is greater than 4 mm, the influences of the fluctuation on the circulating injection quantity and the peak pressure are weak, and the consistency is significantly improved.

Key words: Diesel engine; Circulating injection quantity; Electronic unit pump; Consistency

摘要： 柴油机各缸循环喷油量波动变化影响发动机动力性和排放特性。为了研究电控单体泵 组合泵低压设计因素对循环喷油量波动的影响规律，论文结合理论分析和数值建模方法对其 进行研究。研究结果表明，各缸循环喷油量和高压油管泵端峰值压力的一致性随低压供油压 力和组合泵主、次油道直径增加而提高，影响逐渐趋于一致，且存在拐点。当低压油路供油 压力大于 6 bar、主油道直径大于 8 mm、次油道直径大于 4 mm 后，对高低燃油压力波动的包 容性增强，循环喷油量的波动减弱，一致性明显提高。

关键词: 柴油机；循环喷油量；电控单体泵；一致性