直喷式柴油机喷油特性的测试分析

Measurement and Analysis of Fuel Injection Characteristics of a Direct Injection Diesel Engine

为分析柴油机的燃烧过程和性能 ,在喷油泵试验台上用 W.Bosch长管法研究了喷油过程。介绍了试验装置和原理 ,分析了测试精度。试验结果表明 :喷油管内气泡产生与压力波尾部形状有关 ;长管内残余压力很低 ,燃油声速接近理论声速 ;喷油率图近似于梯形 ,燃油喷射呈“先急后缓”的特征 ;喷油压力、喷油始点、喷油持续角和喷油率均取决于柴油机转速和负荷。

In order to analyze the combustion process and performance of a diesel engine,the fuel injection process was investigated by using W.Bosch long-tube method on an injection pump test stand. The measuring apparatus and the measuring principle and accuracy were presented. The experimental results show that the bubble emergence in high-pressure line relates to the tail configuration of the pressure wave,the residual long-tube pressure is very low,and the sound speed in the tube approaches the theoretical value. The injection rate pattern approximates a trapezoid with a steep front lateral side and a gentle back one. The injection pressure,timing,duration and rate depend on the engine speed and load.