Abstract: In an internal combustion engine, a hydrocarbon feed valve and an exhaust purification catalyst are arranged in an engine exhaust passage. A first NOX removal method which reduces NOX contained in an exhaust gas by a reducing intermediate which is generated by injecting hydrocarbons from the hydrocarbon feed valve within a predetermined range of period and a second NOX removal method in which an air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst is made rich by a period which is longer than this predetermined range are used. The switching temperatures ST and ST0 of the exhaust purification catalyst at which temperature an NOX removal method is switched from the second NOX removal method to the first NOX removal method, are made lower if the amount of NOX in the exhaust gas flowing into the exhaust purification catalyst increases.

Abstract: In an internal combustion engine, a hydrocarbon feed valve and an exhaust purification catalyst are arranged in an engine exhaust passage. A first NOX removal method which injects hydrocarbons from the hydrocarbon feed valve within a predetermined range of period so that the reducing intermediate generated thereby reduces the NOX contained in the exhaust gas and a second NOX removal method which makes the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst a first target rich air-fuel ratio by a period which is longer than this predetermined range are used. When the NOX removal method is switched from the second NOX removal method to the first NOX removal method, the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst is made a second target air-fuel ratio which is smaller than the first target rich air-fuel ratio.

Abstract: In an internal combustion engine, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged in an engine exhaust passage. When releasing the stored NOx from the exhaust purification catalyst (13), usually combustion gas of a rich air-fuel ratio is generated in the combustion chamber (2) to make the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst (13) rich. When releasing the stored NOx from the exhaust purification catalyst (13) in case where the temperature of the exhaust purification catalyst (13) is low, the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst (13) is made rich by injecting hydrocarbons from the hydrocarbon feed valve (15).

Abstract: An internal combustion engine in which a hydrocarbon feed valve, exhaust purification catalyst, and NOX selective reduction catalyst are arranged in an engine exhaust passage. A first NOX removal method which injects hydrocarbons from the hydrocarbon feed valve within a predetermined range of period and uses the reducing intermediate which is generated due to this so as to reduce the NOX contained in the exhaust gas and a second NOX removal method which makes the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst rich with a period longer than this predetermined range are used. When the first NOX removal method should be used and the amount of adsorbed ammonia at the NOX selective reduction catalyst is large, use of the first NOX removal method is stopped.

Abstract: There is provided a method of manufacturing a rotor that includes a permanent magnet inserted into a magnet-insert hole formed in a rotor core, a positioning member which is inserted into the magnet-insert hole and positions the permanent magnet with respect to the rotor core, and a resin material for fixing the permanent magnet to the magnet-insert hole by filling the magnet-insert hole with the resin material. In the method, a mold unit is provided above or below the rotor core, and another positioning member used for manufacturing another rotor is molded using the mold unit while filling the magnet-insert hole with the resin material.

Abstract: In an internal combustion engine, an exhaust purification catalyst (13), hydrocarbon feed valve (15) and particulate filter (14) are arranged in an exhaust passage. If temperature increasing control should be performed when a first NOX purification method is performed, injection of hydrocarbons for the first NOX purification method is performed with a predetermined period and injection of hydrocarbons for temperature increasing control is performed in a time period when injection of hydrocarbons for the first NOX purification method is not performed, the first NOX purification method being configured to purify NOX which is contained in the exhaust gas by injecting hydrocarbons from the hydrocarbon feed valve with the predetermined period, the temperature increasing control being configured to increase a temperature of the particulate filter to remove particulate matters trapped on the particulate filter.

Abstract: A method for purifying exhaust gas of an internal combustion engine including flowing an exhaust gas containing NOx and a concentration of hydrocarbons in an exhaust gas passage that contains an exhaust purification catalyst, wherein the concentration of hydrocarbons is vibrated within a predetermined range of amplitude and period, and a least a portion of the hydrocarbons are reformed by the exhaust purification catalyst; reacting the NOx contained in the exhaust gas and the reformed hydrocarbons to produce a reducing intermediate; and chemically reducing, wherein at the time of engine operation, a demanded produced amount of the reducing intermediate required for chemically reducing the NOx is calculated, and the amplitude and vibration period of the concentration of hydrocarbons flowing into the exhaust purification catalyst are controlled so that an amount of the reducing intermediate produced becomes the demanded produced amount.

Abstract: A frame equipped membrane electrode assembly is formed by joining a membrane electrode assembly (MEA) having different sizes of components together with a resin frame member. A frame shaped adhesive sheet is provided between an inner extension of the resin frame member and an outer marginal portion of the MEA. An inner marginal portion of the adhesive sheet includes an overlapped portion, which overlaps in an electrode thickness direction with the surface of an outer marginal portion of a second gas diffusion layer.

Abstract: A straight-flow exhaust purification catalyst (13) and a hydrocarbon supply valve (15) are arranged in the engine exhaust passage of an internal combustion engine. A region which is a limited portion of the upstream-side end-surface peripheral part of the exhaust gas purification catalyst (13), where there is a possibility of clogging due to deposition oh fine particles in the exhaust gas, is predicted to be a fine particle deposition region, and an air-fuel ratio sensor (23) is arranged within an exhaust gas circulation region, which is downstream from the downstream-side end-surface peripheral part of the exhaust purification catalyst (13) and is downstream from the fine particle deposition region when viewed along the longitudinal axis of the exhaust purification catalyst.

Abstract: A three way catalyst and an NOx storage catalyst are arranged in an engine exhaust passage. In an engine low load operating region, a combustion is performed under a lean air-fuel ratio, and when NOx should be released from the NOx storage catalyst, the air-fuel ratio in a combustion chamber is made rich. In an engine medium load operating region, the base air-fuel ratio is made lower as compared with the engine low load operating region, and the air-fuel ratio in the combustion chamber is made rich at a shorter period as compared with the engine low load operating region. When the operating state of the engine is switched from the engine low load operating region to the engine medium load operating region, the air-fuel ratio in the combustion chamber is temporarily made rich, and the degree of richness of the air-fuel ratio at this time is stepwise lowered.

Abstract: A fuel addition valve that adds fuel into the exhaust gas passage of the engine in the form of fine fuel droplets, an upstream NOx adsorption-reduction catalyst, and a downstream NOx adsorption-reduction catalyst are arranged in this order. Platinum Pt and palladium Pd, as noble metal, are supported on the downstream NOx adsorption-reduction NOx catalyst such that the ratio of the mole number of the platinum Pt to the sum of the mole numbers of the platinum Pt and the palladium Pd is approx. 50% to approx. 80%. Only platinum Pt is supported on the upstream NOx adsorption-reduction catalyst. According to this structure, even when liquid fuel is supplied into exhaust gas, NOx can be effectively released from the NOx adsorption-reduction catalyst, and further the amount of NOx that the NOx adsorption-reduction catalyst can adsorb at a low temperature increases.

Abstract: A hydrocarbon feed valve and an exhaust purification catalyst are arranged in an engine exhaust passage. A first NOX purification method which injects hydrocarbons from the hydrocarbon feed valve by a predetermined period to thereby remove NOX which is contained in the exhaust gas and a second NOX purification method which makes the air-fuel ratio of the exhaust gas which flows into the exhaust purification catalyst rich to make the exhaust purification catalyst release the stored NOX when the NOX which is stored in the exhaust purification catalyst exceeds a first allowable value are selectively used. Hydrocarbons are injected from the hydrocarbon feed valve by the predetermined period, and when the NOX which is stored in the exhaust purification catalyst exceeds a second allowable value which is smaller than the first allowable value, the air-fuel ratio of the exhaust gas which flows into the exhaust purification catalyst is made rich.

Abstract: An exhaust purification system of an internal combustion engine is provided with an exhaust purification catalyst where NOX which is contained in exhaust gas and modified hydrocarbons react. The exhaust purification catalyst carries precious metal catalysts and is formed with a basic exhaust gas flow surface part. The exhaust purification catalyst has the property of reducing NOX if making the concentration of hydrocarbons which flow into the exhaust purification catalyst vibrate by within a predetermined range of amplitude and within a predetermined range of period. The system estimates the holding ability by which the NOX in the exhaust gas is held on the basic exhaust gas flow surface part of the exhaust purification catalyst and, when the holding ability becomes less than a predetermined judgment value of the holding ability, makes the concentration of hydrocarbons which flow into the exhaust purification catalyst rise.

Abstract: In an internal combustion engine of the present invention, an exhaust purification catalyst (13) and a hydrocarbon supply valve (15) are disposed in an engine exhaust path, and NOx contained in exhaust gas is purified by injecting hydrocarbon from the hydrocarbon supply valve (15) at a predetermined cycle. With respect to the injection amount per unit time of the hydrocarbon from the hydrocarbon supply valve (15), there is a difference provided between the first half and the second half of one injection time period, and in the first-half injection time period (Y), the injection amount per unit time of hydrocarbon is made to be less as compared to the second-half injection time period (X).

Abstract: An exhaust purification system of an internal combustion engine provided with an exhaust purification catalyst which reacts NOX and hydrocarbons. The exhaust purification catalyst includes an upstream side catalyst and a downstream side catalyst. The upstream side catalyst has an oxidation ability, while the downstream side catalyst carries precious metal catalyst particles on the exhaust flow surface and is formed with basic exhaust flow surface parts. The exhaust purification catalyst can make the concentration of hydrocarbons vibrate by within a predetermined range of amplitude and by within a predetermined range of period so as to partially oxidize the hydrocarbons or produce reducing intermediates at the upstream side catalyst. When the temperature of the upstream side catalyst is less than a first judgment temperature and the temperature of the downstream side catalyst is higher than a second judgment temperature, the temperature of the upstream side catalyst is made to rise.

Abstract: An exhaust gas purification apparatus for an internal combustion engine comprises a NOx selective reduction catalyst provided in an exhaust passage of an internal combustion engine; an upstream side oxidation catalyst which is a catalyst having an oxidizing ability provided in the exhaust passage upstream from the NOx selective reduction catalyst and which includes a carrier for carrying a noble metal for oxidation, the carrier being formed of a basic carrier; and a reducing agent supply until which supplies a reducing agent to an exhaust gas allowed to flow into the NOx selective reduction catalyst. Accordingly, even when the oxidation catalyst causes the SOx poisoning in the exhaust gas purification apparatus for the internal combustion engine having the oxidation catalyst and the NOx selective reduction catalyst provided in the exhaust passage, the reduction efficiency of NOx reduced by the aid of the NOx selective reduction catalyst is favorably maintained.

Abstract: In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. The concentration of hydrocarbons which flows into the exhaust purification catalyst (13) is made to vibrate by within a predetermined range of amplitude of a 200 ppm or more and within a predetermined range of period of 5 second or less, whereby the NOx which is contained in exhaust gas is reduced at the exhaust purification catalyst (13). At this time, the nitrogen-containing intermediate which is produced in the NOx reduction process is exhausted from the exhaust purification catalyst (13). An intermediate purification catalyst (14) for removal of the exhausted nitrogen-containing intermediate is arranged downstream of the exhaust purification catalyst (13).

Abstract: A three-way catalyst (20) having an oxygen storage function and an exhaust purification catalyst (22) are arranged in the exhaust passage of an internal combustion engine. During medium-load operation of the engine the degree of lean of the air-fuel ratio in the combustion chamber (5) is increased so as to increase the oxygen storage amount of the three-way catalyst (20) to the maximum oxygen storage amount, and the air-fuel ratio in the combustion chamber (5) even after the oxygen storage amount of the three-way catalyst (20) has reached the maximum oxygen, storage amount is maintained at lean, after which the air-fuel ratio is returned to rich, and at this time, as the amount of poisoning of a noble metal catalyst when the air-fuel ratio in the combustion chamber (5) is rich increases, the amount of time for which the air-fuel ratio in the combustion chamber (5) is maintained at lean is increased.

Abstract: In an internal combustion engine, an exhaust purification catalyst: (13), particulate filter (14), and hydrocarbon feed valve (15) are arranged in an engine exhaust passage. A low pressure exhaust gas recirculation system (LPL) is provided for making the exhaust gas downstream of the particulate filter (14) recirculate. If hydrocarbons are injected from the hydrocarbon feed valve (15), the carbon dioxide which is produced in the exhaust purification catalyst (13) is recirculated and the air-fuel ratio of the exhaust gas which flows into the exhaust purification catalyst (13) temporarily drops. At the time of regeneration of the particulate filter (14), hydrocarbons are injected from, the hydrocarbon feed valve (15) so as not to overlap with this temporary drop of the air-fuel ratio.

Abstract: In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. At the time of engine operation, the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to become within a predetermined range of amplitude by control of at least one of the injection time and injection pressure of hydrocarbons from the hydrocarbon feed valve (15). In this case, when only the injection time of hydrocarbons is controlled, the injection time of hydrocarbons under the same engine operating state is made longer the higher the temperature of the exhaust purification catalyst (13).