Abstract: An ammonia selective reduction-type NOx catalyst (48) is interposed in an exhaust passage of an engine (2) provided in a series-type hybrid electric vehicle (1), and a urea water injector (52) is disposed in the exhaust passage to supply a urea water into exhaust gas existing upstream of the ammonia selective reduction-type NOx catalyst (48). The engine (2) is started and stopped in accordance with the storage state of a battery (8), and the urea water injector (52) is controlled in accordance with the operating state of the engine (2). When the engine (2) is to be stopped, an adsorption increasing operation for increasing the amount of ammonia adsorbed by the ammonia selective reduction-type NOx catalyst (48) is executed over a predetermined period before the engine (2) is stopped.

Abstract: An exhaust purification apparatus for an engine comprises an upstream casing that has a cylindrical shape and accommodates a particulate filter; an exhaust gas outlet that is formed in a side wall of the upstream casing and discharges the exhaust gas that has passed through the particulate filter; a urea-water injector that is fixed to the upstream casing located in a position opposite to the exhaust gas outlet and injects urea-water toward the exhaust gas outlet; and a downstream casing that accommodates an ammonia selective reduction-type NOx catalyst into which the exhaust gas discharged from the exhaust gas outlet flows.

Abstract: An exhaust purification apparatus comprises an ammonia selective reduction-type NOx catalyst that selectively reduces NOx within exhaust gas by using ammonia as a reducing agent, a urea-water supply device that supplies urea-water into the exhaust gas existing upstream of the ammonia selective reduction-type NOx catalyst, and a control unit. The control unit controls the urea-water supply device so that the urea-water is intermittently supplied according to predetermined supply duration time and predetermined supply suspension time when the urea-water is supplied from the urea-water supply device for the purpose of providing ammonia to the ammonia selective reduction-type NOx catalyst.

Abstract: An ammonia selective reduction-type NOx catalyst (48) is interposed in an exhaust passage of an engine (2) provided in a series-type hybrid electric vehicle (1), and a urea water injector (52) is disposed in the exhaust passage to supply a urea water into exhaust gas existing upstream of the ammonia selective reduction-type NOx catalyst (48). The engine (2) is started and stopped in accordance with the storage state of a battery (8), and the urea water injector (52) is controlled in accordance with the operating state of the engine (2). When the engine (2) is to be stopped, an adsorption increasing operation for increasing the amount of ammonia adsorbed by the ammonia selective reduction-type NOx catalyst (48) is executed over a predetermined period before the engine (2) is stopped.

Abstract: An ammonia selective reduction-type NOx catalyst (48) is interposed in an exhaust passage of an engine (2) installed in a series-type hybrid electric vehicle (1), and a urea-water injector (62) for supplying urea water in the upstream side of the ammonia selective reduction-type NOx catalyst (48) is placed in the exhaust passage. The engine (2) started in response to a storage state of a battery (8) is operated in a first operation mode, and urea water supply is suspended, until exhaust temperature reaches predetermined temperature (Ta). Once the exhaust temperature reaches the predetermined temperature (Ta), the engine (2) is operated in a second operation mode, and urea water is supplied from the urea-water injector (62). While the engine (2) is operated in the first operation mode, NOx emissions from the engine (2) are more decreased than in the second operation mode.

Abstract: An exhaust gas purification device includes a NOx adsorption catalyst (36) and HC supply means (48) for adding HC to the exhaust gas flowing to the NOx adsorption catalyst (36). The HC supply means (48) is controlled first to supply an amount of HC required to keep the temperature of the NOx adsorption catalyst (36) at a second temperature which is derived by subtracting a temperature rise caused by rich spike from a first temperature predetermined as a temperature necessary for S purge, thereby increasing the temperature of the NOx adsorption catalyst (36), and then to additionally perform the rich spike for the S purge while continuing the HC supply.

Abstract: An exhaust purification apparatus comprises an ammonia selective reduction-type NOx catalyst that selectively reduces NOx within exhaust gas by using ammonia as a reducing agent, a urea-water supply device that supplies urea-water into the exhaust gas existing upstream of the ammonia selective reduction-type NOx catalyst, and a control unit. The control unit controls the urea-water supply device so that the urea-water is intermittently supplied according to predetermined supply duration time and predetermined supply suspension time when the urea-water is supplied from the urea-water supply device for the purpose of providing ammonia to the ammonia selective reduction-type NOx catalyst.

Abstract: An exhaust purification apparatus for an engine comprises an upstream casing that has a cylindrical shape and accommodates a particulate filter; an exhaust gas outlet that is formed in a side wall of the upstream casing and discharges the exhaust gas that has passed through the particulate filter; a urea-water injector that is fixed to the upstream casing located in a position opposite to the exhaust gas outlet and injects urea-water toward the exhaust gas outlet; and a downstream casing that accommodates an ammonia selective reduction-type NOx catalyst into which the exhaust gas discharged from the exhaust gas outlet flows.

Abstract: An auxiliary agent supply means (32, 58) is provided to supply, upstream of an exhaust gas purification means (24, 56, 78), an auxiliary agent for maintaining the exhaust gas purifying function of the exhaust gas purification means (24, 56, 78). A control means (38) for controlling the auxiliary agent supply means (32, 58), thereby regulating the amount of the auxiliary agent supplied includes a standard supply quantity determination section (40, 50, 68, 86) for determining standard supply quantity of the auxiliary agent required to maintain the exhaust gas purifying function, a target supply quantity determination section (42, 52, 70, 88) for determining target supply quantity of the auxiliary agent, by correcting the standard supply quantity on the basis of exhaust pressure, and a supply control section (44, 54, 72, 90) for controlling the auxiliary agent supply means to supply the auxiliary agent in the target supply quantity.

Abstract: An engine control system includes an EGR device 10 which connects an exhaust passage Ex and an intake passage I and has an EGR valve; an intake throttle valve 41 placed in the intake passage I; and an engine control unit which is provided with an engine operation data calculator A1 accumulating mileages of a vehicle or an engine operation period, a fuel injection controller A2 controlling a fuel injection amount and a fuel injection timing, an EGR controller A3 controlling an opening of the EGR valve; a throttle valve controller A4 controlling an opening of the intake throttle valve; and an EGR passage cleaning controller A5 which delays a fuel injection timing Tn, increases an opening ? g of the EGR valve, and reduces an opening ? s of the intake throttle valve when the total mileage or the total operation period calculated by the engine operation data calculator becomes equal to a predetermined threshold.

Abstract: There is provided an oxidizing catalyst located in the upstream of the exhaust gas purifying catalyst. The catalyst capacity of the oxidizing catalyst is set so that, in the relationship between a value obtained by dividing exhaust flow velocity by the catalyst capacity (exhaust flow velocity/catalyst capacity) and catalyst activatibility, when the exhaust flow velocity is exhaust flow velocity at the time of idle operation of the internal combustion engine, the catalyst activatibility is maximum (prescribed maximum activation range) and the value obtained by dividing the exhaust flow velocity by the catalyst capacity is maximum or close to the maximum.

Abstract: An engine control system includes an EGR device 10 which connects an exhaust passage Ex and an intake passage I and has an EGR valve; an intake throttle valve 41 placed in the intake passage I; and an engine control unit which is provided with an engine operation data calculator A1 accumulating mileages of a vehicle or an engine operation period, a fuel injection controller A2 controlling a fuel injection amount and a fuel injection timing, an EGR controller A3 controlling an opening of the EGR valve; a throttle valve controller A4 controlling an opening of the intake throttle valve; and an EGR passage cleaning controller A5 which delays a fuel injection timing Tn, increases an opening ? g of the EGR valve, and reduces an opening ? s of the intake throttle valve when the total mileage or the total operation period calculated by the engine operation data calculator becomes equal to a predetermined threshold.

Abstract: An exhaust gas purifying device for an engine according to the present invention includes a NOx absorbing catalytic converter provided in an exhaust path of the engine, an exhaust light oil adding injector which supplies a reducing agent component into the exhaust path, a control unit which executes the rich spike operation that controls an air-fuel ratio to the rich side per predetermined time, which adds the HC component to the NOx absorbing catalytic converter, and which heats to an S purge temperature or higher so as to eliminate a sulfur component absorbed by the NOx absorbing catalytic converter, and a catalyst temperature measuring sensor which measures the temperature of the NOx absorbing catalytic converter, wherein the control unit controls an operation cycle of the rich spike operation based on the deviation of the S purge temperature with respect to the temperature measured by the catalyst temperature measuring sensor.

Abstract: An exhaust cleaning device includes a NOx storage reduction catalyst storing NOx when an air-fuel ratio of an inflowing exhaust gas is lean and releasing the stored NOx when the air-fuel ratio of the inflowing exhaust gas is rich; an air-fuel ratio changing unit; a reducing agent supplying unit which adds a reducing agent to the NOx storage reduction catalyst; a temperature detection unit which detects a temperature of the NOx storage reduction catalyst; a poisoning recovery timing judging unit which judges a timing for executing a SOx poisoning recovery process of releasing SOx from the NOx storage reduction catalyst; and a control unit.

Abstract: The present invention is a method for estimating a NOx occlusion amount of a NOx occlusion catalyst interposed in an exhaust passage in an engine, which is constituted such that a NOx occlusion amount is estimated by using a polynomial reflected with NOx occlusion characteristics of a NOx occlusion catalyst and each coefficient of the polynomial is sequentially corrected on the basis of NOx purification rates actually measured.