Abstract: In an internal combustion engine, inside of an engine exhaust passage, a hydrocarbon feed valve (16), an exhaust purification catalyst (13), a particulate filter (14), and an NO2 reduction catalyst (15) 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 the injection amount of hydrocarbons from the hydrocarbon feed valve (16). When the NO2 which is produced at the particulate filter (14) should be reduced to NO, the injection amount of hydrocarbons is increased whereby the pass through amount of hydrocarbons which pass straight through the exhaust purification catalyst (13) is increased.

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 flow into the exhaust purification catalyst (13) is made to vibrate within 200 ppm or more predetermined amplitude and within a 5 second or more predetermined period. At this time, when a predetermined amount or more of NOx is stored in the exhaust purification catalyst (13) or can be stored, the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) is temporarily increased to desorb NOx which is stored at the exhaust purification catalyst (13).

Abstract: An exhaust gas control device of an internal combustion engine has an exhaust treatment device that purifies an exhaust gas. The exhaust gas control device is formed such that unburned fuel is supplied into the exhaust gas by a fuel addition valve, and the unburned fuel is ignited by a glow plug, to generate thereby a flame that reaches an upstream end of an exhaust treatment device. The unburned fuel is caused to become adhered to the upstream end of the exhaust treatment device before a generated flame reaches the exhaust treatment device. Then, the unburned fuel adhered to the upstream end of the exhaust treatment device burns by the flame.

Abstract: A method according to the present invention of heating exhaust gas to be introduced into an exhaust gas purifying device from an internal combustion engine by heating and igniting fuel supplied into an exhaust passage from a fuel supply valve includes the steps of determining a necessity for supplying fuel into the exhaust passage, setting an amount of fuel to be supplied into the exhaust passage from the fuel supply valve, the amount being set when it is judged in the determining step that fuel needs to be supplied into the exhaust passage, checking an operating state of the engine, and controlling an air-fuel ratio of exhaust gas such that the air-fuel ratio falls within an area where amounts of both smoke and HC to be generated in the exhaust gas are low in the operating state of the engine checked in the checking step.

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: 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: 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 apparatus determines whether or not there is a malfunction in a reducing agent supply apparatus having a reducing agent addition valve provided in the exhaust system of an internal combustion engine. The reducing agent addition valve injects liquid reducing agent into the exhaust gas. A temperature sensing unit that senses the temperature of the exhaust gas is provided at a position in the exhaust system of the internal combustion engine through which the reducing agent injected through the reducing agent addition valve passes. As the reducing agent is injected through the reducing agent addition valve, the temperature decrease of the exhaust gas at the position through which the reducing agent passes is calculated by a temperature decrease calculation unit. Whether or not there is a malfunction in the reducing agent supply apparatus is determined by a diagnosis unit, based on the temperature decrease of the exhaust gas.

Abstract: 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, a first NOx purification method which maintains the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst (13) lean while injecting hydrocarbons from the hydrocarbon feed valve (15) at predetermined feed intervals to thereby remove the NOx which is contained in exhaust gas and a second NOx purification method which switches the air-fuel ratio of the exhaust gas flowing to the exhaust purification catalyst (13) from lean to rich by intervals longer than the above predetermined feed intervals to thereby remove the NOx are selectively used in accordance with the sulfur poisoning of the exhaust purification catalyst (13).

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: In an internal combustion engine, inside an engine exhaust passage, a hydrocarbon feed valve (15) an exhaust purification catalyst (13), and a particulate filter (14) 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. When the stored SOx should be released from the exhaust purification catalyst (13), the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst (13) is made rich, the reducing intermediate built up on the exhaust purification catalyst (13) is made to be desorbed in the form of ammonia, and the desorbed ammonia is used to make the exhaust purification catalyst (13) release the stored SOx.

Abstract: An internal combustion engine wherein an exhaust purification catalyst and a hydrocarbon feed valve are arranged downstream in an exhaust passage. A first NOX purification method, which removes NOX by making a concentration of hydrocarbons that flows into the exhaust purification catalyst vibrate within predetermined amplitude and period ranges and a second NOX purification method which utilizes an adsorption action of NOX to the exhaust purification catalyst are used. A high pressure exhaust gas recirculation system (HPL) causing recirculation of high pressure exhaust gas and a low pressure exhaust gas recirculation system (LPL) causing recirculation of low pressure exhaust gas are provided.

Abstract: A method for purifying exhaust gas of an internal combustion engine, including chemically reducing NOx that is contained in the exhaust gas when a concentration of hydrocarbons flowing into an exhaust purification catalyst is made to vibrate within a predetermined range of amplitude and within a predetermined range of period, wherein, during the chemical reduction, the NOx contained in the exhaust gas is reacted with reformed hydrocarbons to produce a reducing intermediate containing nitrogen and hydrocarbons, a reducing action of the reducing intermediate chemically reduces the NOx, and the NOx is chemically reduced without storing nitrates or with storing a fine amount of the nitrates in a basic layer of the exhaust purification catalyst.

Abstract: Inside of an engine exhaust passage, in order from an upstream side, a hydrocarbon feed valve oxidation catalyst exhaust purification catalyst, and NOX selective reduction catalyst are arranged. By lowering the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst by a predetermined period while maintaining it lean, the NOX is reduced in the exhaust purification catalyst and the NOX which was not reduced at the exhaust purification catalyst is reduced by the ammonia which is adsorbed at the NOX selective reduction catalyst. The air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst is sometimes switched from lean to rich. At this time, the ammonia which was generated at the exhaust purification catalyst is adsorbed at the NOX selective reduction catalyst.

Abstract: An exhaust purification system of an internal combustion engine is provided with an exhaust purification catalyst which removes NOx and a post treatment device. The exhaust purification catalyst has the property of reducing NOx if making the concentration of hydrocarbons vibrate by within a predetermined range of amplitude and within a predetermined range of period and furthermore has the function of oxidizing hydrocarbons. The exhaust purification system feeds hydrocarbons to the exhaust purification catalyst and raises the temperature of the post treatment device as temperature elevation control. The exhaust purification catalyst has a high purification rate range where the NOx purification rate becomes higher than a predetermined rate. In the temperature elevation control, the total feed amount of hydrocarbons is set and the feed period of hydrocarbons is set in the high purification rate range in a region at the end at the short side of feed period of hydrocarbons.

Abstract: Inside of an engine exhaust passage, a hydrocarbon feed valve (15) and an exhaust purification catalyst (13) are arranged. On the exhaust purification catalyst (13), platinum Pt (51) is carried and a basic layer (53) is formed. The concentration of hydrocarbons which flows into the exhaust purification catalyst (13) is made to vibrate within a predetermined range of amplitude and within a predetermined range of period, whereby the NOx which is contained in the exhaust gas is reduced by the exhaust purification catalyst (13). A clogging degree detecting means is provided for detecting a degree of clogging of a nozzle opening of the hydrocarbon feed valve (15). The NOx purification rate is estimated from the degree of clogging of the nozzle opening of the hydrocarbon feed valve (15) which is detected.

Abstract: Inside an engine exhaust passage, in order from the upstream side, a hydrocarbon feed valve, oxidation catalyst, and exhaust purification catalyst are arranged. A first NOx purification method which lowers the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst by a predetermined period while maintaining it lean so as to remove NOx without causing NOx to be stored in the form of nitrates and a second NOx purification method which switches the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst from lean to rich by a period longer than the above period so as to remove NOx are selectively used in accordance with an operating state of the engine.

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: An internal combustion engine in an engine exhaust passage of which a hydrocarbon feed valve and an exhaust purification catalyst are arranged. On the exhaust purification catalyst, platinum Pt is carried and a basic layer is formed. A concentration of hydrocarbons flowing into the exhaust purification catalyst is made to vibrate within a predetermined range of amplitude of 200 ppm or more and within a predetermined range of period of 5 seconds or less whereby NOx which is contained in the exhaust gas is reduced in the exhaust purification catalyst.

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. On the exhaust purification catalyst (13), platinum Pt (51) is carried and a basic layer (53) is formed. At the time of engine operation, a main concentration changing action in which the concentration of hydrocarbons which flow into the exhaust purification catalyst (13) is made to change by a predetermined amplitude (?HA) and predetermined period (?TA) is performed. Furthermore, before each main concentration changing action, an auxiliary concentration changing action in which the concentration of hydrocarbons is made to change by an amplitude (?HB) smaller than the amplitude (?HA) at the time of each main concentration changing action is performed.