供油系统电磁延迟和液力延迟导致实际喷射脉宽与控制信号脉宽之间存在差异。利用由喷雾图像获取的喷雾脉宽作为实际喷射脉宽，对喷雾脉宽与控制信号脉宽之间对应关系进行研究。研究结果表明：单次喷射喷雾脉宽大于控制信号脉宽，且脉宽差量随着喷射压力增大而缩小，与背景气体密度基本无关；多次喷射喷雾脉宽大于控制信号脉宽，且脉宽差随着喷射压力增大而缩小；两次喷射喷雾间隔小于控制信号喷射间隔，且喷射间隔差在不同压力、预喷油量、控制信号间隔下保持不变；燃油融合现象发生的实际临界喷射间隔时间小于由喷油规律所获取的临界喷射间隔时间。本研究提出了利用喷雾对供油系统喷射脉宽进行研究的新思路，并为多次喷射控制策略的优化提供指导。

Electromagnetic and hydraulic delay in fuel supply system will lead to the difference between actual injection pulse width and control signal pulse width. The correspondence between the spray pulse width and the control signal pulse width was studied by taking the spray pulse width obtained from the spray image as the actual spray pulse width. The results showed that the injection width of single injection spray was larger than that of control signal and the width difference decreased with the increase of injection pressure and was basically independent of the background gas density. The same was true for multiple injection. Besides, the spray interval  was smaller than that of control signal and the difference between spray intervals kept the same under different pressures, pilot injection amounts and control signal intervals. The actual critical injection interval of fuel coalescence phenomenon was smaller than that of injection law. The results put forward a new idea to study the pulse width of fuel supply system by using the spray, which provided the guidance for the optimization of multiple injection control strategy.