恒高压喷射的燃油喷射系统研究(一)

Study on "Constant High Pressure Injecting" Fuel Injection System (Part 1)

本文提出了一种新式柴油机喷射系统、其主要特点是:采用液力控制针阀开启和落座,使针阀开启压力和落座压力大大超过传统喷射系统,从而较大幅度地提高了喷射压力和缩短了喷射持续期,特别是能在高压下切断喷射,避免了传统喷射系统存在的喷射后期低压喷射和燃气回窜现象。此外,采取通过柱塞上方充油,无出油阀以及在低压下控制卸载速度等方法,彻底根除了二次喷射、穴蚀以及低速下不正常喷射等现象。在油泵试验台和单缸试验机上进行的喷射特性和发动机性能对比试验表明,新喷射系统切实可行,并能改善柴油机的性能。

In this paper, A new fuel injection system is introduced. The main features are as following. With hydraulic controlling device, the needle valve opening pressure and closing pressure can be much higher than that of the traditional one, which greatly increases the injection pressure and reduces the injection period, so the appearance of low pressure injection or gas re-entering in later part of injection period was avoided. By filling the fuel on the top of the plunger, with no delivery valve and controlling the release speed at low pressure etc, the secondary injection, cavitation and unnormal injection at low speed were eliminated completely. Injection characteristics of the new system were studied on the pump testbed. Comparative tests were made between the new system and the traditional one on a single cylinder engine. The results showed that the new system improved the engine performance effectively.