Patent ID: 6092494
Filing Date: 2000-07-25
Classification: F02B,F02M,Y02T

Abstract:
A two-cycle internal combustion engine comprising:a cylinder block having at least one combustion cylinder that defines a piston cavity of cylindrical shape around a longitudinal cylinder axis;a cylinder head attached to the cylinder block to define a combustion chamber that is in communication with the piston cavity;a piston that reciprocates longitudinally through the piston cavity along the cylinder axis from bottom dead center to top dead center;a spark plug mounted through the cylinder head so that a spark plug ignition electrode is exposed to the combustion chamber;a crankcase connected to the cylinder block to define a charging chamber that is in communication with the piston on the side of the piston opposite the combustion chamber;a transfer passage passing from the charging chamber through a transfer port in the combustion cylinder wall into the portion of the piston cavity communicating with the combustion chamber;an exhaust port passing through the combustion cylinder wall, the exhaust port including a pressure relief notch extending upward from an edge of the exhaust port along the cylinder wall towards top dead center;a fuel injector that sprays fuel into the piston cavity through the combustion cylinder wall; andan electronic control unit that controls the operation of the fuel injector so that fuel injection terminates before the piston completely covers the exhaust port as the piston travels from bottom dead center to top dead center;wherein the pressure relief notch controls pressure rise as the piston covers the exhaust port thereby rendering fuel injection pressure drops across the fuel injector predictable as the piston covers the exhaust port.