Optimum design of nozzles' tribology systems of a diesel engine fuel injector with high values of rail pressure

One of the actual and important problems of modern motor engineering is the improvement of lifetime and ecological parameters with a decreasing of internal combustion engines' (ICE) exhaust gases toxicity. This problem should be solved by means of a detailed focus on the main tribosystem (needle - nozzle's body) of Common Rail (CR) fuel systems of diesel engines. One of the ways which allows one to influence the precision tribocontact's service life, quality of injection and, subsequently, the ecological parameters of diesel engines is the perfection of a nozzle's tribosystem design. The development of a new design of the nozzle, its perfection and experimental estimation of injection parameters with high rail pressures was the main aim and task of the investigation. The main parameters of the fuel injection were estimated with the help of the experimental nozzle under different rail pressures. The experimental nozzle from a hydrauliccontrolled system is used in the CR injector with electro-hydraulic controlling. As a result of the process visualization of fuel injection, the nature of the fuel streams development was established and injection rate characteristics were experimentally determined. The causes of the unstable injection and instability of characteristics under different pressures were determined and recommendations for improving the design of the nozzle with additional precision tribo-interface were presented.