INJECTION-IN-CYLINDER TYPE INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To produce ignitable optimum air-fuel mixture around an ignition plug. CONSTITUTION:An ignition plug is arranged at the central part of the inner wall surface of a cylinder head, and a fuel injection valve 14 is arranged to the peripheral edge part of the inner wall surface of the cylinder head. A recessed part 15 demarcated by a pair of side wall surfaces 15b extended in a manner that it is gradually spread from below the ignition plug toward the fuel injection valve 14 side and an approximately flat bottom wall surface 15c is formed in the top surface of a piston 2. The side wall surface 15b of each recessed part is extended from an end part 15a of the recessed part, formed below the ignition plug, approximately straightly toward the fuel injection valve 14 side. The bottom wall surface 15c of the recessed part is formed in the shape of a waveform in cross section being the shape of a waveform formed in the flow direction of fuel. Fuel is obliquely injected from the fuel injection valve 14 toward the bottom wall surface 15c of the recessed part. The injected fuel colliding with the bottom wall surface 15c of the recessed part is pointed to the end part 15a of the recessed part below the ignition plug while it is caused to flow along one side wall surface 15b of the recessed part.