EXHAUST GAS PURIFICATION APPARATUS OF INTERNAL COMBUSTION ENGINE

摘要

An exhaust gas purification apparatus of an internal combustion engine includes: an NH3 generating catalyst which generates NH3 from NOx and H2 at a rich air-fuel ratio; an in-cylinder injection valve which injects fuel into a cylinder; and a control apparatus which, when setting a rich air-fuel ratio, sets a timing of fuel injection from the in-cylinder injection valve to a second half of a compression stroke when a temperature of the NH3 generating catalyst is within a first prescribed range and sets a timing f of fuel injection from the in-cylinder injection valve to a first half of an intake stroke when the temperature of the NH3 generating catalyst is within a second prescribed range that is a higher temperature range than the first prescribed range.

主权项

1. An exhaust gas purification apparatus of an internal combustion engine, comprising:
an NH3 generating catalyst which is provided in an exhaust passage of the internal combustion engine and which generates NH3 from NOx and H2 when an air-fuel ratio of exhaust gas is lower than a stoichiometric air-fuel ratio; a detector which detects a temperature of the NH3 generating catalyst; an in-cylinder injection valve which injects fuel into a cylinder of the internal combustion engine; and a control apparatus configured to set the air-fuel ratio of exhaust gas lower than the stoichiometric air-fuel ratio to generate NH3 by the NH3 generating catalyst, wherein the control apparatus is configured to, when setting the air-fuel ratio of exhaust gas lower than the stoichiometric air-fuel ratio, set a timing of fuel injection from the in-cylinder injection valve to a second half of a compression stroke in a case where the temperature of the NH3 generating catalyst as detected by the detector is within a first prescribed range and set a timing of fuel injection from the in-cylinder injection valve to a first half of an intake stroke in a case where the temperature of the NH3 generating catalyst as detected by the detector is within a second prescribed range that is a higher temperature range than the first prescribed range.