电磁直接驱动式二甲醚喷射器特性试验

利用FJ-600瞬态喷射率测量仪，对一种电磁直接驱动式二甲基醚喷射器的喷射特性进行了试验，发现该喷射器在一定的工作范围内，存在着循环供油量随燃料喷射压力减小或喷射背压增大而增大的现象．这一现象将会影响发动机的燃料控制精度，进而影响发动机的燃烧与排放性能．分析确定，出现上述现象的主要原因在于喷射压力和喷射背压直接影响喷射器针阀的起落运动，造成针阀开启截面和实际开启持续期的明显变化，从而导致循环供油量的变化．提高喷射器的电磁驱动力，增加回位弹簧的刚度，将有利于改善此喷射器循环供油量特性．

Experimental Study on the Injection Characteristics of a Dimethyl Ether Injector Driven by Electromagnetic Force Directly

The study is based on FJ-600 pilot injection measuring system. It is found that the injection quantities increase with the fuel injection pressure's decrease or the back pressure's increase in some working conditions,which would affect the fuel supply accuracy and engine performances. This is because the needle movements are affected by the fuel pressure and back pressure directly,the injector's effective flow section and real injection duration change obviously.Increasing the spring stiffness and electromagnetic force will be of benefit to improving the injector's injection characteristic.