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: A porous carbon sheet obtained by binding separate carbon short fibers with a carbonization product of a resin, wherein the pore mode diameter of the sheet is 45 to 90 ?m and the mean fiber diameter of the carbon short fibers is 5 to 20 ?m. The sheet can be produced by thermoforming a precursor fiber sheet comprising carbon short fibers of 15 to 30 g/m2 in basis weight and a thermosetting resin of 30 to 80 g/m2 in basis weight by hot plates having a certain clearance and carbonizing the thermosetting resin contained in thermoformed precursor fiber sheet.

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 the injection amount of hydrocarbons from the hydrocarbon feed valve (15), the concentration of hydrocarbons flowing into the exhaust purification catalyst (13) is made to vibrate by a predetermined range of period by control of the injection period of hydrocarbons from the hydrocarbon feed valve (15), and thereby the NOx contained in the exhaust gas and the NOx stored in the exhaust purification catalyst (13) are reduced.

Abstract: A method of purifying NOX contained in exhaust gas, the method including a first NOX purification method and a second NOX purification method, wherein the first NOX purification method and the second NOX purification method include injecting hydrocarbons into an exhaust gas passage at predetermined feed intervals, wherein in the first method, the injected hydrocarbons are partially oxidized and an air-fuel ratio flowing into an exhaust purification catalyst is lean, and in the second method, the injection of the hydrocarbons occurs at intervals longer than the predetermined feed intervals in the first method, and an air-fuel ratio is switched from lean to rich.

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 (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 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: In an internal combustion engine, inside of an engine exhaust passage in order from an upstream side, a hydrocarbon feed valve, oxidation catalyst, and exhaust purification catalyst are arranged. On the exhaust purification catalyst, platinum and rhodium are carried and a basic layer is formed. Hydrocarbons are intermittently fed from the hydrocarbon feed valve while maintaining the air-fuel ratio of the exhaust gas flowing into the exhaust purification catalyst lean. At this time, the feed of hydrocarbons is controlled so as to ensure the continued presence of the reducing intermediate on the basic layer.

Abstract: An exhaust purification system of an internal combustion engine is provided with a hydrocarbon feed valve which is arranged in an engine exhaust passage and an exhaust purification catalyst which reacts the NOX which is contained in exhaust gas and reformed hydrocarbons. It is formed to perform first operational control which feeds hydrocarbons from the hydrocarbon feed valve by within a predetermined range of amplitude and within a predetermined range of period and second operational control wherein the amount of feed of hydrocarbons from the hydrocarbon feed value in a predetermined time becomes greater than in the first operational control. In the second operational control, hydrocarbons are fed from the hydrocarbon feed valve by an injection pressure which is smaller than the injection pressure of hydrocarbons in the first operational control.

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).

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 exhaust purification catalyst (13) is comprised of an upstream-side catalyst (14a) and a downstream-side catalyst (14b) arranged in series at an interval from each other. The upstream-side catalyst (14b) has a smaller cross-sectional area than the downstream-side catalyst (14b). The concentration of hydrocarbons which flow into the upstream-side catalyst (14a) 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 seconds or less, whereby the NOx which is contained in exhaust gas is reduced at the exhaust purification catalyst (13).

Abstract: An exhaust purification system of an internal combustion engine is provided with an exhaust treatment device which purifies exhaust, a fuel feed device which is arranged at an upstream side from the exhaust treatment device and which feeds fuel to the engine exhaust passage, an ignition device which causes fuel which is fed from the fuel feed device to ignite, and a flow regulating device which regulates the flow rate of exhaust gas which flows toward the ignition device. The fuel feed device is formed so as to feed liquid fuel. The system has an operating region in which due to the fuel which is fed to the engine exhaust passage burning, backflow of the exhaust gas occurs. Fuel is made to burn in the operating region. Further control is performed to make the flow rate of the exhaust gas increase during the period from when combustion of fuel should be started to when combustion of the fuel ends.

Abstract: An internal combustion engine in an engine exhaust passage of which an exhaust purification catalyst (13) having an oxidation function is arranged and in the engine exhaust passage upstream of the exhaust purification catalyst (13) of which a small-sized oxidation catalyst (14) and a fuel feed valve (15) for feeding fuel to the small-sized oxidation catalyst (14) are arranged. When activating the exhaust purification catalyst (13), the fuel fed from the fuel injector (15) is used to heat the small-sized oxidation catalyst (14) and when the exhaust purification catalyst (13) is further raised in temperature, the fuel fed from the fuel feed valve (15) is increased and reformed fuel is exhausted from the small-sized oxidation catalyst (14).

Abstract: An exhaust purification system of an internal combustion engine provided with an NOx storage reduction catalyst an oxidation catalyst which is arranged downstream of the NOx storage reduction catalyst an exhaust gas tank which is connected to the engine exhaust passage between the NOx storage reduction catalyst and the oxidation catalyst, and a switching valve which closes the engine exhaust passage toward the oxidation catalyst and makes the exhaust gas flow into the tank. When making the air-fuel ratio of the exhaust gas which flows into the NOx storage reduction catalyst rich, the engine exhaust passage toward the oxidation catalyst is shut and the flow path is switched so that the exhaust gas flows to the tank to thereby store the exhaust gas in the tank.

Abstract: The present invention provides an exhaust purifying apparatus in an internal combustion engine provided with an exhaust treatment device in an exhaust passage. The exhaust purifying apparatus comprises an oxidation device provided upstream of the exhaust treatment device, a fuel adding valve for adding fuel upstream of the oxidation device, and a glow plug provided upstream of the oxidation device for heating the fuel added from the fuel adding valve. The oxidation device is formed to be provided with gas passages the number of which is equal to or more than 30 and is equal to or less than 200 per 0.00064516 m2 in an exhaust flow passage direction cross-section.

Abstract: A technique is provided which is capable of reducing an amount of smoke generated in a temperature raising system in which fuel added to an exhaust gas flowing through an exhaust passage is caused to combust at the time of requesting a temperature rise in an exhaust gas purification catalyst. When a request for raising the temperature of an exhaust gas purification catalyst is made, bypass control is carried out in which the exhaust gas having bypassed a turbine is caused to flow into the exhaust gas purification catalyst through a bypass passage, and fuel ignition control is carried out in which a fuel addition valve is caused to add fuel to the exhaust gas which has flowed out of the turbine, and a glow plug is caused to ignite the added fuel.

Abstract: A technique is provided that can complete reduction and release of SOx from a storage-reduction type NOx catalyst in a shorter period of time in a SOx regeneration treatment of bringing an air-fuel ratio and temperature in the storage-reduction type NOx catalyst to a state where the reduction and release of the SOx is possible by alternately executing rich burn in which burning in a cylinder of an internal combustion engine is performed at a rich air-fuel ratio and lean burn in which the burning is performed at a lean air-fuel ratio. By supplying fuel to exhaust gas from a fuel addition valve provided to an exhaust pipe during a lean period in which the lean burn is executed, the temperature of the storage-reduction type NOx catalyst is maintained at a temperature that enables the reduction and release of the SOx. During a rich period in which the rich burn is executed, a rich atmosphere of the storage-reduction type NOx catalyst is achieved to cause the reduction and release of the SOx.

Abstract: An exhaust purification system of an internal combustion engine is provided with a hydrocarbon feed valve arranged in an engine exhaust passage and an exhaust purification catalyst for causing NOX contained in exhaust gas and reformed hydrocarbons to react. The exhaust purification catalyst reduces NOX if a concentration of inflowing hydrocarbons vibrates within a predetermined range of amplitude and within a predetermined range of period and increases the amount of storage of NOX if the vibration period of the concentration of hydrocarbons longer is than a predetermined range. When hydrocarbons are being fed from the hydrocarbon feed valve within the predetermined range of amplitude and the predetermined range of period, if the amount of adsorption of hydrocarbons in the exhaust purification catalyst exceeds a predetermined judgment value of the adsorption amount, at least one of reducing amount of feed of hydrocarbons and lengthening feed interval of hydrocarbons is performed.

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: 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 by 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).