Search Results

The development of environmental improvement technologies in the automobile industry is underway. These technologies are also developed for internal combustion engines, which remain the mainstream power source for most vehicles. Nissan Motor Company has developed a multi-locking hydraulic VTC (Valve Timing Control) system and adopted it on the newly developed QR25DER engine of the Pathfinder and Infiniti JX hybrid vehicles. The implementation of the developed system allows for an optimized variable valve timing at both, cold engine start, and idle stop re-start from EV mode. This paper describes an outline, the principle, and effects of the multi locking hydraulic VTC system.

This paper presents the effect of fuel atomization at an intake manifold on the combustion characteristics of a spark-ignition engine. Four sets of fuel-supply devices were tested which have much difference in atomization characteristics in terms of the mean droplet size ranging from wall film to 7 um S.M.D. Over the whole operatable range of mixture strength, the fuel atomization did not give any effect on BMEP, BSFC and volumetric efficiency, but had an effect on the engine stability at lean operation limit under most operating conditions. This atomization effect was shown to be systematically characterized by mapping on the ignition timing and A/F plane. The appearance of partial-burn limit on the map was successfully verified by the combustion analysis using a correlation procedure on cycle by cycle basis.