Method for controlling the injection and ignition in a direct-injection endothermic engine, in order to accelerate heating of the catalytic converter

Abstract

Method for controlling the injection and ignition in a direct-injection endothermic engine, in order to accelerate heating of a catalytic converter , which is disposed along the exhaust pipe of the engine, The method comprising the steps of executing, during a single cycle of the engine, and for each cylinder of the engine itself, at least a first injection of fuel, during suction stroke and/or compression stroke of the cylinder itself, in order to supply a weak mixture; priming combustion in each cylinder, at a priming moment which is pre-determined such that the combustion in each cylinder generates the same torque; and executing, in at least one cylinder of the engine, a second injection of fuel, during the exhaust stroke of the cylinder itself, such that the ratio of air/fuel of the mixture as a whole, which is supplied to the cylinder during suction stroke, compression stroke, expansion stroke and exhaust stroke, is close to the stoichiometric value; the fuel which is injected in the said second injection giving rise to residual combustion in the presence of the oxygen-rich exhaust gases, which are derived from the combustion of the weak mixture; the residual combustion not affecting the torque generated, and producing heat in order to speed up heating of the catalytic converter.