Abstract: In order to improve performance of NOx reduction, an additional fuel injection immediately after a main fuel injection is performed. By such additional fuel injection, hydrogen (H2) is supplied to a NOx trap catalyst. And in order to prevent engine output torque from varying by the additional fuel injection, the main fuel injection is controlled by whether the additional fuel injection is performed.

Abstract: An exhaust gas purifying system for an internal combustion engine mounted on an automotive vehicle. The exhaust gas purifying system includes an exhaust gas component concentration regulating device disposed in an exhaust gas passageway of the engine, for regulating concentrations of gas components in exhaust gas discharged from the engine such that the concentrations of carbon monoxide and hydrogen are respectively not more than 2.0% by volume and not less than 0.5% by volume and such that a volume concentration ratio of [hydrogen/carbon monoxide] is not smaller than 0.5, in rich and stoichiometric conditions of exhaust gas. Additionally, a NOx adsorbing and reducing catalyst is disposed in the exhaust gas passageway downstream of the exhaust gas component concentration regulating device, for adsorbing nitrogen oxides in a lean condition of the exhaust gas and reducing the nitrogen oxides into nitrogen in the rich and stoichiometric conditions.

Abstract: A fuel reforming system has a reformer (4) for reforming a fuel to produce a reformate gas; a shift converter (5) for reacting carbon monoxide (CO) contained in a reformate gas with water to produce hydrogen (H2); a CO oxidizer (6) which removes CO discharged from the shift converter; and a startup combustor (11) for supplying combustion gas to the reformer (4), a shift converter (5) and CO oxidizer (6) to warm up them. An NOx trap (16) is disposed downstream of the startup combustor so as to adsorb nitrogen oxides (NOx) in combustion gas. A fuel reforming system further has a controller for controlling warm-up operations. When the warm-up operation for the reformer, the shift converter and the CO oxidizer is completed, the reformate reactions are commenced in the reformer (4). The NOx trapped by the NOx trap is decomposed by the reformate gas which contains CO gas and H2 gas.

Abstract: An exhaust gas purifying system for an internal combustion engine mounted on an automotive vehicle. The exhaust gas purifying system comprises an exhaust gas component concentration regulating device disposed in an exhaust gas passageway of the engine, for regulating concentrations of gas components in exhaust gas discharged from the engine such that the concentrations of carbon monoxide and hydrogen are respectively not more than 2.0% by volume and not less than 0.5 by volume and such that a volume concentration ratio of [hydrogen/carbon monoxide] is not smaller than 0.5, in rich and stoichiometric conditions of exhaust gas. Additionally, a NOx adsorbing and reducing catalyst is disposed in the exhaust gas passageway downstream of the exhaust gas component concentration regulating device, for adsorbing nitrogen oxides in a lean condition of the exhaust gas and reducing the nitrogen oxides into nitrogen in the rich and stoichiometric conditions.

Abstract: An exhaust gas purifying system for an internal combustion engine mounted on an automotive vehicle. The exhaust gas purifying system may include an exhaust gas component concentration regulating device disposed in an exhaust gas passageway of the engine, for regulating concentrations of gas components in exhaust gas discharged from the engine such that the concentrations of carbon monoxide and hydrogen are respectively not more than 2.0% by volume and not less than 0.5 by volume and such that a volume concentration ratio of hydrogen/carbon monoxide is not smaller than 0.5, in a first exhaust gas condition in which air/fuel ratio of exhaust gas is within a range of from a rich value and a stoichiometric value.

Abstract: In order to improve performance of NOx reduction, an additional fuel injection immediately after a main fuel injection is performed. By such additional fuel injection, hydrogen (H2) is supplied to a NOx trap catalyst. And in order to prevent engine output torque from varying by the additional fuel injection, the main fuel injection is controlled by whether the additional fuel injection is performed.

Abstract: An exhaust gas purifying system for an internal combustion engine mounted on an automotive vehicle. The exhaust gas purifying system comprises an exhaust gas component concentration regulating device disposed in an exhaust gas passageway of the engine, for regulating concentrations of gas components in exhaust gas discharged from the engine such that the concentrations of carbon monoxide and hydrogen are respectively not more than 2.0% by volume and not less than 0.5 by volume and such that a volume concentration ratio of [hydrogen/carbon monoxide] is not smaller than 0.5, in a first exhaust gas condition in which air/fuel ratio of exhaust gas is within a range of from a rich value and a stoichiometric value.

Abstract: An exhaust gas purifying system for an automotive internal combustion engine. The exhaust gas purifying system comprises a flow-through monolithic catalyst disposed in an exhaust gas passageway through which exhaust gas flows. The monolithic catalyst functions to adsorb and oxidize a soluble organic fraction in exhaust gas, to adsorb nitrogen oxides in exhaust gas in a condition in which a temperature of exhaust gas is not higher than 200° C. and to allow carbon particle in exhaust gas to pass through the monolithic catalyst. Additionally, a filter catalyst is disposed in the exhaust gas passageway downstream of the flow-through monolithic catalyst. The filter catalyst functions to trap the carbon particle and to oxidize hydrocarbons, carbon monoxide and nitrogen monoxide in exhaust gas.

Abstract: A nitrogen oxide absorbing material (38) which absorbs nitrogen oxide when the reduction component concentration of exhaust gas in the exhaust passage (31) of an engine (1) is lower than a predetermined concentration, and discharges nitrogen oxide when the reduction component concentration of exhaust gas in the exhaust passage (31) of the engine (1) is higher than the predetermined concentration, and a catalyst (38) which promotes reduction of the discharged nitrogen oxides by a reduction component are provided. A controller (40) first reduces the reduction component concentration of the exhaust gas over a first predetermined time period by, for example, advancing the fuel injection timing. The controller (40) then increases the reduction component concentration of the exhaust gas over a second predetermined time period by, for example, retarding the fuel injection timing.

Abstract: An exhaust gas purifying catalyst for purifying exhaust gas discharged from an internal combustion engine of an automotive vehicle. The exhaust gas purifying catalyst comprises a substrate on which a catalytic coat layer containing a catalyst component is formed. The catalytic coat layer is formed by coating a slurry containing the catalyst component on a surface of the substrate. A crack-preventing coat layer is formed on an upper-most surface of the catalytic coat layer. The crack-preventing coat layer has a thickness of not larger than 50 &mgr;m.