Abstract: In an internal combustion engine, inside an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. A first hydrocarbon feed method which injections hydrocarbons from the hydrocarbon feed valve (15) by predetermined feed intervals (?T) so that the air-fuel ratio of the exhaust gas falls to the demanded minimum air-fuel ratio (X) to thereby remove the NOx contained in the exhaust gas and a second hydrocarbon feed method which lowers the feed amount of hydrocarbons from the hydrocarbon feed valve (15) and feeds fuel to the combustion chambers (2) during a second half of the expansion stroke or the exhaust stroke are selectively used.

Abstract: An exhaust purification system of an internal combustion engine is provided with an exhaust purification catalyst which includes an upstream side catalyst and a downstream side catalyst and which makes NOX and hydrocarbons react. The upstream side catalyst has an oxidation ability, while the downstream side catalyst carries precious metal catalyst particles on an exhaust flow surface and is formed with basic exhaust flow surface parts. The exhaust purification catalyst makes the concentration of hydrocarbons vibrate by within a predetermined range of amplitude and by within a predetermined range of period so as to remove the NOX. The upstream side catalyst has a high efficiency temperature at which hydrocarbons can be partially oxidized by a predetermined efficiency.

Abstract: An exhaust purification system is provided with an NOx storage reduction catalyst arranged in an exhaust passage and an SOx trap material arranged upstream of the NOx storage reduction catalyst and removes SOx contained in exhaust gas. A main flow path has a secondary flow path connected to it. In the secondary flow path, a removal device is arranged for removing the sulfur constituent contained in fuel. The secondary flow path includes an opening and closing device. When the SOx removal rate of the SOx trap material becomes a predetermined removal rate judgment value or less or the concentration of the SOx which flows into the SOx trap material becomes a predetermined concentration judgment value or more, at least part of the fuel flowing through a main flow path is made to flow into the secondary flow path and run through the removal device.

Abstract: An exhaust purification system of an internal combustion engine is provided with an exhaust purification catalyst which includes an upstream side catalyst and a downstream side catalyst and removes NOX. The upstream side catalyst has an oxidation ability, while the downstream side catalyst has catalyst particles of precious metals and basic exhaust flow surface parts. The system makes the concentration of hydrocarbons which flow into the exhaust purification catalyst vibrate by within a predetermined range of amplitude and by within a predetermined range of period and reduces the NOX. The upstream side catalyst includes an upstream side substrate and an upstream side container, while the downstream side catalyst includes a downstream side substrate, a downstream side container, and a channel of exhaust between the downstream side substrate and the downstream side container.

Abstract: An electronic control unit executing an algorithm so as to operate an exhaust purification system of an engine. The algorithm (1) commences a regeneration treatment by causing an amount of fuel supplied to a combustion process of the engine to increase so as to change an air-fuel ratio of exhaust gas of the engine from a first lean air-fuel ratio to a set rich air-fuel ratio and (2) causes uncombusted fuel to be supplied to a NOx catalyst device during at least one of: a first period in which an air-fuel ratio of the exhaust gas within the NOx catalyst device changes from the first lean air-fuel ratio to the set rich air-fuel ratio when the regeneration treatment is started; and a second period after an air-fuel ratio of the exhaust gas within the NOx catalyst device becomes a ratio indicating completion of the regeneration treatment.

Abstract: In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (16), an exhaust purification catalyst (13), an aqueous urea solution feed valve (17), and an NOx selective reduction catalyst (15) are arranged in that order. A first NOx purification method which makes the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) vibrate by within predetermined ranges of amplitude and period to reduce the NOx, which is contained in exhaust gas in the exhaust purification catalyst (13) and a second NOx purification method which uses the fed aqueous urea solution to reduce the NOx in the NOx selective reduction catalyst (15) are selectively used.

Abstract: In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (16), an exhaust purification catalyst (13), an aqueous urea solution feed valve (17), and an NOx selective reduction catalyst (15) are arranged in that order. A first NOx purification method which makes the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) vibrate by within predetermined ranges of amplitude and period to reduce the NOx contained in exhaust gas in the exhaust purification catalyst (13) is normally used. A second NOx purification method which uses the fed aqueous urea solution to reduce the NOx in the NOx selective reduction catalyst (15) is used when the fed hydrocarbons exceed the allowable value.

Abstract: In an internal combustion engine, inside of an engine exhaust passage, an upstream side air-fuel ratio sensor (23), a hydrocarbon feed valve (15), an exhaust purification catalyst (13), and a downstream side air-fuel ratio sensor (24) are arranged in this order from the upstream. At the time of engine operation, the injection amount of hydrocarbons from the hydrocarbon feed valve (15) is controlled based on the air-fuel ratio detected by the upstream side air-fuel ratio sensor (23) and the downstream side air-fuel ratio sensor (24) so that the amplitude of change of the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) becomes within a predetermined range of amplitude.

Abstract: An internal combustion engine in an engine exhaust passage of which a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. If the hydrocarbon feed valve (15) feeds hydrocarbons by a period of within 5 seconds, a reducing intermediate is produced inside the exhaust purification catalyst (13). This reducing intermediate is used for NOX purification processing. At the time of engine operation, the demanded produced amount of the reducing intermediate required for reducing the NOx is calculated. The amount of production of the reducing intermediate is made to become this demanded produced amount by control of the feed amount and feed period of hydrocarbons.

Abstract: The present detector for detecting sulfur components includes a storage portion for storing SOx and NOx in the exhaust gas passing through an exhaust passage, in which the more an amount of stored SOx increases, the more an amount of stored NOx decreases, and which does not release SOx but release NOx at a set temperature, and a temperature sensor, estimates the amount of stored SOx on the basis of a relationship between, after the storage portion becomes the set temperature by heating, a heating pattern of the storage portion and temperature change of the storage portion measured by the temperature sensor, and detects an integrated amount of SOx passing through the exhaust passage during a given period or an value on the basis of the integrated amount.

Abstract: An internal combustion engine in which an SOx trap catalyst for trapping SOx contained in the exhaust gas is comprised of an upstream side catalyst and a downstream side catalyst into which the exhaust gas flowing out from the upstream side catalyst flows. The SOx storing material of the upstream side catalyst is mainly comprised of an alkali earth metal, while the SOx storing material of the downstream side catalyst is mainly comprised of an alkali metal.

Abstract: The exhaust purification system of an internal combustion engine of the present invention is provided with an NOX storage reduction catalyst and a particulate filter which is arranged at the upstream side of the NOX storage reduction catalyst. When causing the NOX storage reduction catalyst to release the stored NOX, the particulate filter is raised to the temperature at which the particulate matter is oxidized, the flow rate of the exhaust gas which flows into the particulate filter is made to decrease, the air-fuel ratio of the exhaust gas which flows into the particulate filter is made rich, and the particulate matter which builds up on the particulate filter is made to oxidize to produce carbon monoxide.

Abstract: An exhaust purification system of an internal combustion engine has a selective reduction type NOX catalyst device which can hold ammonia and a storage reduction type NOX catalyst device which is arranged at an upstream side of the selective reduction type NOX catalyst device, which makes an air-fuel ratio of exhaust gas which flows into the storage reduction type NOX catalyst device change from a lean air-fuel ratio to a rich air-fuel ratio for starting an ammonia generation period, and which makes an air-fuel ratio of exhaust gas which flows into the storage reduction type NOX catalyst device change from a rich air-fuel ratio to a lean air-fuel ratio for ending the ammonia generation period.

Abstract: An internal combustion engine in which an SOx trap catalyst (13) for trapping SOx contained in the exhaust gas contains an oxygen adsorbing and releasing material (54) which can adsorb SO2 contained in the exhaust gas and an SOx storage material (55) which can store SOx in the form of sulfates. The SO2 which is contained in the exhaust gas is chemically adsorbed at the oxygen adsorbing and releasing material (54) without being oxidized. If the temperature of the SOx trap catalyst (13) becomes higher than the start temperature of adsorbed SO2 movement, the SO2 which is chemically adsorbed at the oxygen adsorbing and releasing material (54) is oxidized and stored in the form of sulfates in the SOx storage material (55).

Abstract: An exhaust purification system of an internal combustion engine including an ammonia oxidation catalyst device and an ammonia holding device arranged immediately upstream of the ammonia oxidation catalyst device is provided. The ammonia holding device has a solid acid, holds ammonia to restrain the ammonia from flowing into the ammonia oxidation catalyst device when a temperature of the ammonia oxidation catalyst device is within a N2O producing temperature range, and releases the held ammonia to make the ammonia flow into the ammonia oxidation catalyst device when the temperature of the ammonia oxidation catalyst device is out of the N2O producing temperature range.

Abstract: An exhaust purification system is provided with an NOx storage reduction catalyst arranged in an exhaust passage and an SOx trap material arranged upstream of the NOx storage reduction catalyst and removes SOx contained in exhaust gas. A main flow path has a secondary flow path connected to it. In the secondary flow path, a removal device is arranged for removing the sulfur constituent contained in fuel. The secondary flow path includes an opening and closing device. When the SOx removal rate of the SOx trap material becomes a predetermined removal rate judgment value or less or the concentration of the SOx which flows into the SOx trap material becomes a predetermined concentration judgment value or more, at least part of the fuel flowing through a main flow path is made to flow into the secondary flow path and run through the removal device.

Abstract: The exhaust purification system of an internal combustion engine is provided with an NOX selective reduction catalyst which is arranged in an engine exhaust passage and which has the function of absorbing NOX which is contained in exhaust gas when an air-fuel ratio of inflowing exhaust gas is lean, releasing the absorbed NOX when the air-fuel ratio of the inflowing exhaust gas becomes a stoichiometric air-fuel ratio or rich, and selectively reducing the NOX and with a fuel addition valve which feeds fuel to the NOX selective reduction catalyst. In the case of the region near the stoichiometric air-fuel ratio in the region where the air-fuel ratio of the exhaust gas flowing into the NOX selective reduction catalyst is lean, the fuel addition valve is used to feed fuel to the NOX selective reduction catalyst to selectively reduce the NOX.

Abstract: A temperature sensor includes temperature detecting means and at least one of a catalyst and an adsorbent applied to the surface of the temperature detecting means. At least one of the catalyst and the adsorbent catalyzes an exothermic reaction of a reactant in gas on the temperature detecting means. A temperature that is increased by the exothermic reaction is detected by the temperature detecting means. The catalytic efficiency for the exothermic reaction of at least one of the catalyst and the adsorbent is reduced by sulfur poisoning. The temperature sensor is disposed upstream of an exhaust purification system. Accordingly, it is determined that the temperature sensor is subjected to sulfur poisoning if the temperature detected by the temperature sensor is below a prescribed temperature.

Abstract: In an exhaust purification system of an internal combustion engine, comprising a NOX catalyst device, which can satisfactorily store NOX in the exhaust gas when the concentration of oxygen in the exhaust gas is high and can release the stored NOX and purify the released NOX to N2 by reducing materials in the exhaust gas when the concentration of oxygen is decreased as a regeneration treatment, the regeneration treatment is carried out to change a combustion air-fuel ratio from a lean air-fuel ratio to a set rich air-fuel ratio, and N2O reducing material is supplied to the NOX catalyst device during at least one of a first period set within a period in which an air-fuel ratio in the exhaust gas within said NOX catalyst device changes from the lean air-fuel ratio to the set rich air-fuel ratio when the regeneration treatment is started and a second period set within a period after an air-fuel ratio in the exhaust gas within the NOX catalyst device becomes the stoichiometric air-fuel ratio when the regeneration

Abstract: An exhaust purification system of an internal combustion engine arranging in an engine exhaust passage an NOx storing reducing catalyst storing NOx contained in exhaust gas when an air-fuel ratio of inflowing exhaust gas is lean and reducing and purifying stored NOx when the air-fuel ratio of the inflowing exhaust gas becomes a stoichiometric air-fuel ratio or rich, which system is provided with an NOx production reducing means for reducing an amount of production of NOx produced in a combustion chamber due to change of a combustion state of the engine and temporarily reduces the amount of production of NOx by the NOx production reducing means when an amount of N2O flowing out from the NOx storing reducing catalyst is anticipated to exceed an allowable amount.