Abstract: A filter is disposed on an exhaust path of the internal combustion engine to capture particulate matter exhausted from the internal combustion engine. A controller is caused to execute regeneration control that incinerates the particulate matter captured on the filter. The controller accomplishes the regeneration control by executing lean incineration control and stoichiometric incineration control in combination with each other. The lean incineration control incinerates the particulate matter, keeping an air-fuel ratio of the internal combustion engine to be leaner than a logical air-fuel ratio. The stoichiometric incineration control incinerates the particulate matter, oscillating the air-fuel ratio of the internal combustion engine about the logical air-fuel ratio as an average air-fuel ratio at a predetermined first cycle.

Abstract: An exhaust gas purification system for an engine includes an exhaust passage extending from the combustion chambers of the engine, and an exhaust purifying unit disposed in the exhaust passage and configured to purify exhaust gas in the exhaust passage. The exhaust purifying unit includes a carrier disposed in the exhaust passage, a first purifier having at least a function of oxidizing components in the exhaust gas. The first purifier covers, as an underlayer, an outer surface of the carrier, and a second purifier having a function of purifying the exhaust gas by reducing, using occluded ammonia, the components in the exhaust gas that have been oxidized in the first purifier. The second purifier includes a superposed portion covering, as an upper layer, an outer surface of the first purifier.

Abstract: A filter is disposed on an exhaust path of the internal combustion engine to capture particulate matter exhausted from the internal combustion engine. A controller is caused to execute regeneration control that incinerates the particulate matter captured on the filter. The controller accomplishes the regeneration control by executing lean incineration control and stoichiometric incineration control in combination with each other. The lean incineration control incinerates the particulate matter, keeping an air-fuel ratio of the internal combustion engine to be leaner than a logical air-fuel ratio. The stoichiometric incineration control incinerates the particulate matter, oscillating the air-fuel ratio of the internal combustion engine about the logical air-fuel ratio as an average air-fuel ratio at a predetermined first cycle.

Abstract: An exhaust gas purification system for an engine includes an exhaust passage extending from the combustion chambers of the engine, and an exhaust purifying unit disposed in the exhaust passage and configured to purify exhaust gas in the exhaust passage. The exhaust purifying unit includes a carrier disposed in the exhaust passage, a first purifier having at least a function of oxidizing components in the exhaust gas. The first purifier covers, as an underlayer, an outer surface of the carrier, and a second purifier having a function of purifying the exhaust gas by reducing, using occluded ammonia, the components in the exhaust gas that have been oxidized in the first purifier. The second purifier includes a superposed portion covering, as an upper layer, an outer surface of the first purifier.

Abstract: A controlling device for purifying exhaust gas includes: a fuel cutting controller (2) that, if a predetermined condition for fuel cutting is satisfied, shuts off supply of fuel to an engine (10) after a predetermined delay time (B) elapses; a calculator (3) that calculates oxygen occludability of a catalyst (6, 7) being interposed in an exhaust system of the engine (10) and containing an oxygen occludable material; and a setter (4) that sets a length of the delay time (B) in accordance with the oxygen occludability calculated by the calculator (3).

Abstract: An object of at least one embodiment of the present invention is to suppress poisoning due to phosphorus derived from engine oil, and effectively purify NOx discharged from the time of engine start up to a high load condition. In an exhaust gas purification catalyst for an internal combustion engine, a catalyst layer includes: a first catalyst layer exposed to an exhaust gas flow; and a second catalyst layer formed between the first catalyst layer and the substrate. A second catalyst upstream layer formed on an upstream side of the second catalyst layer with respect to the exhaust gas flow and a first catalyst downstream layer formed on a downstream side of the first catalyst layer with respect to the exhaust gas flow include at least one of palladium and platinum, as well as an oxygen storage material as the catalyst component. An amount of the oxygen storage material in the first catalyst downstream layer is larger than an amount of the oxygen storage material in the second catalyst upstream layer.

Abstract: A controlling device for purifying exhaust gas includes: a fuel cutting controller (2) that, if a predetermined condition for fuel cutting is satisfied, shuts off supply of fuel to an engine (10) after a predetermined delay time (B) elapses; a calculator (3) that calculates oxygen occludability of a catalyst (6, 7) being interposed in an exhaust system of the engine (10) and containing an oxygen occludable material; and a setter (4) that sets a length of the delay time (B) in accordance with the oxygen occludability calculated by the calculator (3).

Abstract: An object is to provide an exhaust gas purification catalyst for an internal combustion engine that can achieve a higher exhaust gas purification performance and a higher engine output performance. A catalyst layer is disposed in an exhaust gas passage, formed on a surface of the substrate, and includes: a first catalyst layer exposed to an exhaust gas flow; and a second catalyst layer formed between the first catalyst layer and the substrate. A catalyst component supported on the first catalyst layer includes rhodium. A catalyst component supported on the second catalyst layer includes at least one of palladium and platinum.

Abstract: An object of at least one embodiment of the present invention is to suppress poisoning due to phosphorus derived from engine oil, and effectively purify NOx discharged from the time of engine start up to a high load condition. In an exhaust gas purification catalyst for an internal combustion engine, a catalyst layer includes: a first catalyst layer exposed to an exhaust gas flow; and a second catalyst layer formed between the first catalyst layer and the substrate. A second catalyst upstream layer formed on an upstream side of the second catalyst layer with respect to the exhaust gas flow and a first catalyst downstream layer formed on a downstream side of the first catalyst layer with respect to the exhaust gas flow include at least one of palladium and platinum, as well as an oxygen storage material as the catalyst component. An amount of the oxygen storage material in the first catalyst downstream layer is larger than an amount of the oxygen storage material in the second catalyst upstream layer.

Abstract: A method of purifying an exhaust gas, includes: disposing a NOx trapping catalyst in an exhaust pipe of an internal combustion engine, the NOx trapping catalyst including: a metal substrate including cells, a corner portion of each of cells having an acute angle; and a catalyst layer supported in the metal substrate and including a noble metal, a heat-resistant inorganic oxide and a NOx trapping material, the catalyst layer having pores formed by addition of a pore formation promoting material, and the NOx trapping catalyst: adsorbing NOx in the exhaust gas when an exhaust air-fuel ratio is in a lean state; and desorbing and reducing the adsorbed NOx when the exhaust air-fuel ratio is in a stoichiometric state or a rich state; and removing the NOx by the exhaust air-fuel ratio being shifted between the lean state and the rich state.

Abstract: An exhaust gas purifying catalyst which is disposed in an exhaust pipe of an internal combustion engine, includes: a substrate; and a catalyst layer, supported in the substrate and including: noble metals including platinum (Pt) and palladium (Pd); a heat-resistant inorganic oxide; and a NOx trapping material. The exhaust gas purifying catalyst adsorbs NOx in an exhaust gas when an exhaust air-fuel ratio is in a lean state and desorbs and reduces the adsorbed NOx when the exhaust air-fuel ratio is in a stoichiometric state or a rich state. (Pt/Pd) which is a ratio of amount of the platinum (Pt) to amount of the palladium (Pd) is 0.7 or more and less than 1.0.

Abstract: A fuel control device for an internal combustion engine determines that the internal combustion engine is in a transient state, by a criterion D, and makes fuel correction, where the transient-state criterion D is set to be a more relaxed criterion (=|?THaf|) when forcible modulation control is being performed, compared with a normal criterion (=|?THn|) used when the forcible modulation control is not being performed.

Abstract: An exhaust gas purifying catalyst includes: a substrate; and a catalyst layer supported on the substrate and including: a surface layer including: rhodium (Rh); and a first support material including zirconia (ZrO2); and an inner surface layer including: palladium (Pd); and a second support material including magnesia (MgO).

Abstract: A method of purifying an exhaust gas, includes: disposing a NOx trapping catalyst in an exhaust pipe of an internal combustion engine, the NOx trapping catalyst including: a metal substrate including cells, a corner portion of each of cells having an acute angle; and a catalyst layer supported in the metal substrate and including a noble metal, a heat-resistant inorganic oxide and a NOx trapping material, the catalyst layer having pores formed by addition of a pore formation promoting material, and the NOx trapping catalyst: adsorbing NOx in the exhaust gas when an exhaust air-fuel ratio is in a lean state; and desorbing and reducing the adsorbed NOx when the exhaust air-fuel ratio is in a stoichiometric state or a rich state; and removing the NOx by the exhaust air-fuel ratio being shifted between the lean state and the rich state.

Abstract: An exhaust gas purifying catalyst which is disposed in an exhaust pipe of an internal combustion engine, includes: a substrate; and a catalyst layer, supported in the substrate and including: noble metals including platinum (Pt) and palladium (Pd); a heat-resistant inorganic oxide; and a NOx trapping material. The exhaust gas purifying catalyst adsorbs NOx in an exhaust gase when an exhaust air-fuel ratio is in a lean state and desorbs and reduces the adsorbed NOx when the exhaust air-fuel ratio is in a stoichiometric state or a rich state. (Pt/Pd) which is a ratio of amount of the platinum (Pt) to amount of the palladium (Pd) is 0.7 or more and less than 1.0.

Abstract: An exhaust emission purification catalyst which purifies exhaust gas of an engine, includes: a carrier which is formed with a plurality of cell holes; and a plurality of catalytic layers which are carried in the plurality of cell holes. The plurality of catalytic layers includes: a first layer including an auxiliary catalyst that includes a zeolite including a transition metal that occludes NOx in the exhaust gas during a time period of low temperature; and a second layer disposed adjacent to a surface of the first layer and including a main catalyst that includes at least one of an alkali metal and an alkali earth metal and that occludes the NOx occluded in the auxiliary catalyst when temperature of the main catalyst reaches active temperature.

Abstract: A fuel control device for an internal combustion engine determines that the internal combustion engine is in a transient state, by a criterion D, and makes fuel correction, where the transient-state criterion D is set to be a more relaxed criterion (=|?THaf|) when forcible modulation control is being performed, compared with a normal criterion (=|?THn|) used when the forcible modulation control is not being performed.

Abstract: As forcible modulation parameters, a cycle and an amplitude are set so that O2 and CO concentrations in emissions at a catalyst inlet can be increased, and based upon the preset parameters, forcible modulation that forcibly fluctuates an exhaust air-fuel ratio is carried out to facilitate catalysis for early activation, and the forcible modulation is then switched to O2-F/B control.

Abstract: By performing main fuel injection and sub fuel injection to perform rich operation of an engine, NOx purging of a NOx catalyst is carried out, and in the NOx purging, the ratio between the main fuel injection quantity and the sub fuel injection quantity is variably determined, within the range of 5:1 to 2:1 where the ratio of the sub fuel injection quantity is relatively great, such that the ratio of the sub fuel injection quantity is greater as the temperature of a three-way catalyst becomes higher.

Abstract: There is provided an exhaust emission purifying catalyst device which is comprised of a carrier disposed in an exhaust passage and including through holes passed through the carrier in an axial direction (flowing direction), and supporting layers made of fire-resistance inorganic oxide formed on inner surfaces of the through holes. The supporting layers support noble metal and NOx trapping agents which occlude NOx in exhaust gas when the exhaust air-fuel ratio is lean, and emits and reduces the occluded NOx when the exhaust air-fuel ratio is stoichiometric or rich. The amount of the supported noble metal is set to be smaller in an exhaust passage upstream area of the carrier than in an exhaust passage downstream area of the carrier.