中文摘要：

电控组合泵是集机械、液力和电磁于一体的系统,是一种满足柴油机排放和经济性的新型电控单体泵喷油系统。其低压系统压力动态特性影响了高压系统各缸循环喷射特性的一致性。试验研究表明,在工作时低压系统燃油压力一直处于脉动的循环波动,压力波动范围从最小接近表压0MPa到最大2MPa,波动效应幅值随着喷油脉宽的增加而增大,并且不同测试位置压力波动特性存在微小的不同,压力波形时域曲线与喷油缸数有一一对应关系。对其进行傅里叶变换得出随着工作缸数增加,高压系统对低压系统的影响主要表现在基准频率的倍频部分;对其小波变换得出随着喷油缸数增加,低压压力信号同时向小波变换信号低频和高频方向移动。为了分析低压压力波动对高压喷射特性的影响,采用AMESim软件建立数值模型,计算结果表明各缸低压系统燃油压力和高压系统喷射压力处于循环波动状态,并且各缸存在差别,导致各缸循环喷油量存在微小差别,在1.5mm3内波动,均方差在0.5mm3范围内。

英文摘要：

Electronic control assembly pump（ECAP）assembles mechanical hydraulic and electrical magnetic,and is a new electronic unit pump（EUP）fuel injection system which satisfies requirement of emission and fuel economy of diesel.The low pressure system pressure dynamic characteristic influences the coherence of each cylinder cyclic injection performance on the high pressure system.Experiment shows that the low pressure system fuel pressure always has the pulsating cycle fluctuation in operation,the fluctuation range is from minimum 0 MPa to maximum 2 MPa,the fluctuation amplitude improves with the increase of injection duration,and pressure dynamic characteristic has little difference at different measurement position.Pressure time history curve and injection cylinders have the corresponding relationship.Fourier analysis shows that the influence of high pressure system on low pressure system mainly focuses on the multiple frequency part of datum frequency as working cylinders increase.Wavelet transform shows that low pressure signal simultaneously moves towards low frequency and high frequency of the wavelet transform signal as injection cylinders increase.To analyze the influence of low pressure fluctuation on high pressure injection characteristic,the numerical study is conducted using the AMESim software.Simulation result shows fuel pressures at low pressure system and high pressure system are cyclic fluctuation.Cyclic fuel injection quantity at each cylinder has little difference,the fluctuation range is 1.5 mm3,and mean square deviation is within 0.5 mm3.