Abstract: A device for purifying exhaust gas of an internal combustion engine comprising a NOx catalyst device, fuel feeding means for feeding additional fuel into combusted gas flowing into the NOx catalyst device during the regeneration treatment, and a NOx concentration sensor arranged on the exhaust downstream of the NOx catalyst device, wherein when the NOx concentration detected by the NOx concentration sensor is lower than a preset concentration during the regeneration treatment of this time, the amount of NOx absorbed by the NOx catalyst device during a preset period until the regeneration treatment of the next time is estimated by utilizing the NOx concentration sensor, and when the absorbed amount of NOx is smaller than a preset amount, it is decided that the amount of additional fuel fed during the regeneration processing of this time had been abnormally decreased.

Abstract: An exhaust gas purification system for an internal combustion engine can quickly recover the exhaust gas purification ability of an exhaust gas purification device by increasing opportunities to release the SOx occluded in the exhaust gas purification device. In the exhaust gas purification system having the exhaust gas purification device having the property of occluding the SOx in the exhaust gas emitted from the internal combustion engine and collecting particulate matter contained in the exhaust gas, when the load of the internal combustion engine falls within a load range in which SOx poisoning recovery control can be executed, during the time when the particulate matter is oxidized and removed by collection ability regeneration control (S105), the collection ability regeneration control is interrupted and the SOx poisoning recovery control is executed (S106, S107).

Abstract: A device for purifying exhaust gas of an internal combustion engine is provided, equipped with an HC catalyst having the ability to oxidize HC, as well as adsorb HC, and release HC which it has adsorbed, and there exists a specific condition where the amount to release HC becomes greater than the amount to oxidize HC, wherein the device for purifying exhaust gas of an internal combustion engine executes an HC feed control for feeding HC to the HC catalyst. The amount of HC fed to the HC catalyst is decreased by the HC feed control or the HC feed control is discontinued when the specific condition is established during execution of the HC feed control.

Abstract: When a fuel as a reducing agent is supplied to a NOx catalyst on which a NOx or a SOx is reduced, a flow rate of exhaust gas that flows through an exhaust passage is changed, and the fuel is supplied to the exhaust gas flowing through the exhaust passage at a plurality of timings (?T1, ?T2) when the exhaust gas flows at different flow rates.

Abstract: Art is provided for an exhaust purification system for an internal combustion engine, which decreases an amount of exhaust flowing to a storage-reduction type NOx catalyst and supplies a reducer to the NOx catalyst so as to reduce NOx stored in the NOx catalyst, wherein the manner in which the reducer is dispersed in the NOx catalyst can be controlled to achieve more reliable execution of a NOx reduction treatment. Air-fuel ratio detecting unit is disposed upstream and downstream of the storage-reduction type NOx catalyst. During a predetermined period subsequent to decreasing an amount of exhaust flowing to the NOx catalyst and adding the reducer to the exhaust, a reducer-adding timing is changed such that a difference between an air-fuel ratio detected by the air-fuel ratio detecting unit disposed upstream of the NOx catalyst and an air-fuel ratio detected by the air-fuel ratio detecting unit disposed downstream of the NOx catalyst becomes a predetermined target value.

Abstract: An engine exhaust passage is provided with a fuel addition valve (14) for adding fuel in the form of atomized drops, an oxidation catalyst (11), and an NOx storage and reduction catalyst (12) in that order. The oxidation catalyst (11) carries as a precious metal not only platinum Pt, but also palladium Pd. A molar ratio of the platinum Pt with respect to the sum of the platinum Pt and palladium Pd carried on the oxidation catalyst (11) is set to between about 50 percent to about 80 percent.

Abstract: An exhaust gas purification system for an internal combustion engine can quickly recover the exhaust gas purification ability of an exhaust gas purification device by increasing opportunities to release the SOx occluded in the exhaust gas purification device. In the exhaust gas purification system having the exhaust gas purification device having the property of occluding the SOx in the exhaust gas emitted from the internal combustion engine and collecting particulate matter contained in the exhaust gas, when the load of the internal combustion engine falls within a load range in which SOx poisoning recovery control can be executed, during the time when the particulate matter is oxidized and removed by collection ability regeneration control (S105), the collection ability regeneration control is interrupted and the SOx poisoning recovery control is executed (S106, S107).

Abstract: An exhaust gas purification system for an internal combustion engine can quickly recover the exhaust gas purification ability of an exhaust gas purification device by increasing opportunities to release the SOx occluded in the exhaust gas purification device. In the exhaust gas purification system having the exhaust gas purification device having the property of occluding the SOx in the exhaust gas emitted from the internal combustion engine and collecting particulate matter contained in the exhaust gas, when the load of the internal combustion engine falls within a load range in which SOx poisoning recovery control can be executed, during the time when the particulate matter is oxidized and removed by collection ability regeneration control (S105), the collection ability regeneration control is interrupted and the SOx poisoning recovery control is executed (S106, S107).

Abstract: An exhaust purification device, including a NOx storing catalyst comprised of a precious metal catalyst and NOx absorbent, arranged in an engine exhaust passage, which increases the ratio of the nitrogen dioxide to the nitrogen monoxide produced when burning fuel under a lean air-fuel ratio when the NOx storing catalyst is not active compared with the time when the NOx storing catalyst is active under the same engine operating conditions and stores the nitrogen dioxide contained in the exhaust gas in the NOx absorbent at that time.

Abstract: A NOx storing catalyst (11) comprising a precious metal catalyst (46) and NOx absorbent (47) is arranged in an exhaust passage. When the air-fuel ratio of the exhaust gas is lean, the storing catalyst cold stores the NO2 contained in the exhaust in the absorbent when the catalyst is inactive and hot stores the cold stored NO2 in the absorbent when the catalyst is made active. The NO2 contained in the exhaust is cold stored in the absorbent when the catalyst is not activated, and when a predetermined NOx storing catalyst restoring condition (107) is met, a NOx storing catalyst restoring control (109, 115) including raising the NOx storing catalyst temperature to a predetermined temperature to active it (109) is executed so as to restore the cold storing capability of the NOx absorbent.

Abstract: An exhaust emission purification device comprises a sulfur component holding agent arranged on the exhaust path of an internal combustion engine for holding a sulfur component, a NOx holding agent arranged downstream of the sulfur component holding agent in the exhaust gas for holding NOx and the sulfur components when the air-fuel ratio of the exhaust gas flowing thereinto is lean, and a reducing agent adding unit for adding a reducing agent to the exhaust gas flowing into the NOx holding agent. The concentration of the sulfur component contained in the reducing agent added by the reducing agent adding unit is lower than the concentration of at least the sulfur component contained in the fuel supplied to the combustion chamber of the internal combustion engine. Thus, the sulfur poisoning of the exhaust emission purifier can be avoided while at the same time reducing the fuel consumption rate.

Abstract: Exhaust emission control apparatus and method for an internal combustion engine maintain a small amount of sulfur components contained in exhaust gas flowing out of a sulfur component retainer agent even if the amount of sulfur components retained by the agent becomes great. The exhaust emission control apparatus includes a NOx retainer agent and the sulfur component retainer agent. The apparatus performs a NOx releasing process of adjusting the air-fuel ratio of exhaust gas flowing into the sulfur component retainer agent so that the air-fuel ratio of exhaust gas flowing into the NOx retainer agent becomes substantially stoichiometric or rich of stoichiometry if NOx retained by the NOx retainer agent is to be released. The apparatus prohibits the air-fuel ratio of exhaust gas flowing into the sulfur component retainer agent from becoming substantially stoichiometric or rich of stoichiometry if the amount of the sulfur components retained by the agent is at least a first predetermined amount.

Abstract: There is provided an exhaust gas purification device (22) comprising a substrate used for purifying components contained in an exhaust gas discharged from an engine. The substrate has partitions (54) which define passages (50,51) and are formed of porous material having fine pores each having a predetermined average size. The end portions of the adjacent partitions (54) defining each of part of the passages (50,51) of the substrate are partially connected to each other such that the end portions (52,53) are tapered toward the outside of the substrate. The tapered end portions partially close the end opening of the corresponding passage and form a small hole (55,56) defined by the tips thereof. The size of each small hole (55,56) is smaller than the cross sectional area of the corresponding passage (50) and larger than the sizes of the fine pores of the partitions (54).

Abstract: An internal combustion engine emission control apparatus includes split passages that divide exhaust gas discharged from an internal combustion engine into a plurality of streams. Emission control catalysts are provided that individually divide the exhaust gas in the split passages, and remove a component present in the exhaust gas at a high removal rate if a temperature of exhaust gas that inflows via the split passages satisfies a predetermined temperature condition. A controller changes proportions of the amounts of flow of the exhaust gas into the split passages so that the predetermined temperature condition is satisfied in at least one split passage of the split passages. Therefore, the emission control can be performed in a broad range of changing temperatures of the exhaust gas.

Abstract: An exhaust emission control system for an internal combustion engine includes an exhaust passage that branches into a first exhaust branch passage and a second exhaust branch passage, which join at downstream ends thereof into a common exhaust passage, a NOx catalyst disposed in each of the exhaust branch passages, a particulate filter disposed in the common exhaust passage and located downstream of a joining point of the exhaust branch passages, and flow control valves that control the amounts of exhaust gas flowing through the respective exhaust branch passages.

Abstract: An exhaust gas purification system for an internal combustion engine can quickly recover the exhaust gas purification ability of an exhaust gas purification device by increasing opportunities to release the SOx occluded in the exhaust gas purification device. In the exhaust gas purification system having the exhaust gas purification device having the property of occluding the SOx in the exhaust gas emitted from the internal combustion engine and collecting particulate matter contained in the exhaust gas, when the load of the internal combustion engine falls within a load range in which SOx poisoning recovery control can be executed, during the time when the particulate matter is oxidized and removed by collection ability regeneration control (S105), the collection ability regeneration control is interrupted and the SOx poisoning recovery control is executed (S106, S107).

Abstract: A device for purifying the exhaust gas of an internal combustion engine includes a particulate filter carrying an active-oxygen releasing agent that can cause the sulfur poisoning, a SOx trap unit arranged upstream of the particulate filter, and a bypass section for making the exhaust gas mainly bypass said particulate filter when SOx is released from the SOx trap unit. Further, an exhaust choke valve for an exhaust brake is arranged between the SOx trap unit and the exhaust gas branch portion of the bypass section.

Abstract: An exhaust gas purifying apparatus for an internal combustion engine includes plural catalysts provided in parallel. In a case where temperatures of the catalysts need to be raised, a catalyst is selected from among the catalysts and the exhaust gas is allowed to flow in the selected catalyst. In addition, the temperature of the selected catalyst is raised without using a reducing agent when the temperatures of the catalysts are lower than a temperature range in which the reducing agent can be purified. Alternatively, the reducing agent is supplied to the selected catalyst so as to raise the temperature thereof when the temperatures of the catalysts are equal to or higher than the temperature at which the reducing agent can be purified.

Abstract: An exhaust purification device, including a NOx storing catalyst comprised of a precious metal catalyst and NOx absorbent, arranged in an engine exhaust passage, which increases the ratio of the nitrogen dioxide to the nitrogen monoxide produced when burning fuel under a lean air-fuel ratio when the NOx storing catalyst is not active compared with the time when the NOx storing catalyst is active under the same engine operating conditions and stores the nitrogen dioxide contained in the exhaust gas in the NOx absorbent at that time.

Abstract: An exhaust gas purification device having a NOx absorbent includes a by-pass passage for by-passing the NOx absorbent, an exhaust gas flow rate control portion for regulating both a flow rate of exhaust gas flowing to the NOx absorbent and the flow rate of the exhaust gas bypassing the NOx absorbent, and a reductant addition portion for adding reductant into an exhaust passage upstream of the NOx absorbent. In this device, when it is necessary to discharge sulfur components from the NOx absorbent, a temperature rise control is executed such that a temperature of the NOx absorbent becomes higher than a predetermined temperature. Next, a rich condition control is executed such that an air-fuel ratio of the exhaust gas flowing to the NOx absorbent becomes one of a substantially stoichiometric condition and a rich condition. The flow rate of the exhaust gas to the NOx absorbent during the temperature rise control is controlled so as to be higher than that during the rich condition control.