DIRECT INJECTION TYPE INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To decrease generation amount of NOx by devising the internal combustion engine so that a part of the conical part of fuel spray injected from a fuel injection valve 3 flows along a conical surface while injection pressure and injection rate are restrained low at an injection initial stage and so that a combustion field is kept at a very low temperature, too. CONSTITUTION:A conical part 10 of a gently inclined angle is formed on the bottom part of a combustion chamber 5 of an upper edge open type formed on the upper wall of a piston 1. Additionally, a high pressure injection rate control injection system is set to start fuel injection a little before a top dead center and to restrain injection rate and injection pressure low during an injection initial period near the top dead center. Furthermore, an intercooler 27 connected to a compressor unit 26 of a supercharger 24 is connected to a supply air manifold 21 through a supply air cooling system 30, and after recompressing supercharged air in a compressor unit 31, supply air is lowered down to 0 - 5 deg.C simultaneously when the supply air pressure is lowered by expanding it by an air turbine unit 32.