喷油器弹簧预紧力特性研究

Study on the Characteristics of Spring Preload in Injector

摘要: 在AMESim环境下建立电控单体泵系统的仿真模型，并对比实验结果完成模型标定。研究相同弹簧预紧力作用下，喷油压力、喷油速率、针阀运动速率及喷油量随转速的变化规律。针对不同转速，探索喷油压力、启喷压力、喷油时间及喷油量随弹簧预紧力和转速的变化机理。得出在低转速下，适当减小弹簧预紧力可以防止针阀因燃油建压速率慢而关闭，从而获得良好的喷射特性；在高转速下，弹簧预紧力变化对喷油压力影响很小。

Abstract: The simulate model of EUP system was built in AMESim environment, and the model was cali- brated by comparing with the experiment results. Under the action of the same spring preload, the laws of injection pressure, injection rate, the rate of needle movement and fuel injection quantity which transform with the speed variation were researched. Furthermore, at different speeds, the mechanism of injection pressure, nozzle open pressure, injection duration time and fuel injection quantity which change with spring preload and speeds was explored. Finally, some conclusions have been drawn that at low speeds, reducing the spring preload appropriately can prevent needle closing caused by slower pressure building, and result in a good injection characteristics; at high speeds, spring preload changes have few influence on the injection pressure.