ANALYSIS OF INJECTORS REACTION ON THE EXTERNAL SIGNALS IN DIRECT INJECTION SYSTEMS

Povzetek

The aim of the research was to assess the external signals of fuel injection by piezoelectric injectors of engines fueled with gasoline and diesel fuel. The assessment focused on the delay analysis of fuel injection start in relation to the time of appropriate control signals occured. The research on these relations was conducted with the use of the system for analysing fast-varying processes and high speed camera HSS 5 by LaVision installed in the test stand with constant-volume chamber. The tests were conducted for different injectors with direct injection of liquid fuels under variable conditions: different fuel pressure, air backpressure and injection time. The paper correlates the electric parameters activating injector operation with parameters of actual fuel injection. For this purpose the digital processing of images was applied enabling actual times determination of fuel injection initiation. Essential differences between the activation time of fuel injection and its actual occurrence were pointed out.

Keywords:
fuel injection, injection delay, constant-volume chamber