Abstract: In an exhaust gas purification apparatus for an internal combustion engine (1) equipped with independent exhaust passages (2a, 2b) provided one for each cylinder group (1a, 1b) with a catalyst (3a, 3b) having a NOx trapping ability being arranged in each exhaust passage, the present invention is intended to provide a technique that can independently control the flow rates of exhaust gases flowing into the respective catalysts.

Abstract: An eight-cylinder engine including fuel injection valves provided for each of the eight cylinders. A first valve drive unit for driving four of the eight fuel injection valves to open and close by energizing the four fuel injection valves and a second valve drive unit for driving the other four fuel injection valves to open and close by energizing the second-mentioned four fuel injection valves. Both of the valve drive units drive the fuel injection valves so that combustion and expansion strokes occur at equal intervals, thus allowing for a sufficient charging time for each valve drive unit. For example, the first valve drive unit energizes those fuel injection valves which are provided on a first, fourth, sixth and seventh cylinders, and the second valve drive unit energizes those fuel injection valves which are provided on a second, third, fifth, and eighth cylinders.

Abstract: In an exhaust gas purification apparatus for an internal combustion engine (1) equipped with independent exhaust passages (2a, 2b) provided one for each cylinder group (1a, 1b) with a catalyst (3a, 3b) having a NOx trapping ability being arranged in each exhaust passage, the present invention is intended to provide a technique that can independently control the flow rates of exhaust gases flowing into the respective catalysts.

Abstract: Even in a construction in which fuel injection valves for eight cylinders are energized by two EDUs, a sufficient charging time for each EDU can be ensured. In an eight-cylinder engine including fuel injection valves provided one for each cylinder of the eight-cylinder engine for injecting fuel thereinto, a first valve drive unit for driving four of the eight fuel injection valves to open and close by energizing these four fuel injection valves; and a second valve drive unit for driving four fuel injection valves other than the first-mentioned four fuel injection valves to open and close by energizing the second-mentioned four fuel injection valves, both of the valve drive units drive those fuel injection valves which are provided on cylinders for which combustion and expansion strokes occur at equal intervals.

Abstract: Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.

Abstract: Cylinders of a diesel engine 1 are provided with cylinder pressure sensors 29a to 29d for detecting combustion chamber pressures. An electronic control unit (ECU) 20 of the engine selects optimum combustion parameters in accordance with a fuel injection mode of fuel injectors 10a to 10d of the engine and a combustion mode determined by the amount of EGR gas supplied from the EGR valve 35 from among a plurality of types of combustion parameters expressing the combustion state of the engine calculated based on the cylinder pressure sensor output and feedback controls the fuel injection amount and fuel injection timing so that the values of the combustion parameters match target values determined in accordance with the engine operating conditions. Due to this, the engine combustion state is controlled to the optimum state at all times regardless of the fuel injection mode or combustion mode.

Abstract: Diesel engine is operated in a first warm-up mode in an early warm-up period after startup so as to accelerate activation of the catalyst, and then in a second warm-up mode in a late warm-up period after the early warm-up period so as to maintain activity of the catalyst. The first warm-up mode provides more energy to the catalyst with exhaust gases than the normal operation mode of the diesel engine. The second warm-up mode provides exhaust gases of higher temperature to the catalyst than the normal operation mode.

Abstract: Diesel engine is operated in a first warm-up mode in an early warm-up period after startup so as to accelerate activation of the catalyst, and then in a second warm-up mode in a late warm-up period after the early warm-up period so as to maintain activity of the catalyst. The first warm-up mode provides more energy to the catalyst with exhaust gases than the normal operation mode of the diesel engine. The second warm-up mode provides exhaust gases of higher temperature to the catalyst than the normal operation mode.

Abstract: An engine where first combustion where the amount of the EGR gas in the combustion chamber is larger than the amount of EGR where the amount of production of soot peaks and almost no soot is produced and a second combustion where the amount of EGR gas in the combustion chamber (5) is smaller than the amount of EGR gas where the amount of production of soot peaks are selectively switched between.

Abstract: An internal combustion engine has an EGR passage provided with an EGR control valve and a catalyst for purifying the EGR gas. When the internal combustion engine operates in a low-temperature combustion mode in which the amount of EGR gas supplied to a combustion chamber is larger than that of EGR gas with which the amount of soot produced reaches a peak, and almost no soot is produced, a controller reduces an opening amount of the exhaust gas recirculation control valve so as to increase an exhaust gas temperature, and reduces an opening amount of the throttle valve so as to suppress an increase in the amount of the EGR gas, thereby to reduce reductions in the temperature of the EGR gas and the temperature of the catalyst.

Abstract: An internal combustion engine performs a second mode of combustion where the EGR is less than the EGR gas that peaks the production of soot. The engine then performs a first mode of combustion where the EGR is greater than the EGR that peaks the production of soot. During the second mode, the engine curbs hydrocarbon supplied to an exhaust gas control catalyst by performing a combustion where hydrocarbon does not increase. The exhaust gas temperature discharged becomes relatively high and the EGR rate is set to zero. The engine then increases the hydrocarbon supplied to the catalyst by performing a combustion that increases the hydrocarbon. The temperature of exhaust gas discharged becomes relatively high, and the EGR rate is gradually increased. Accordingly, the engine quickly warms up the catalyst while preventing problems that occur, like clogging of an exhaust gas recirculation passage.

Abstract: An internal combustion engine has an EGR passage provided with an EGR control valve and a catalyst for purifying the EGR gas. When the internal combustion engine operates in a low-temperature combustion mode in which the amount of EGR gas supplied to a combustion chamber is larger than that of EGR gas with which the amount of soot produced reaches a peak, and almost no soot is produced, a controller reduces an opening amount of the exhaust gas recirculation control valve so as to increase an exhaust gas temperature, and reduces an opening amount of the throttle valve so as to suppress an increase in the amount of the EGR gas, thereby to reduce reductions in the temperature of the EGR gas and the temperature of the catalyst.

Abstract: An internal combustion engine performs a second mode of combustion where the EGR is less than the EGR gas that peaks the production of soot. The engine then performs a first mode of combustion where the EGR is greater than the EGR that peaks the production of soot. During the second mode, the engine curbs hydrocarbon supplied to an exhaust gas control catalyst by performing a combustion where hydrocarbon does not increase. The exhaust gas temperature discharged becomes relatively high and the EGR rate is set to zero. The engine then increases the hydrocarbon supplied to the catalyst by performing a combustion that increases the hydrocarbon. The temperature of exhaust gas discharged becomes relatively high, and the EGR rate is gradually increased. Accordingly, the engine quickly warms up the catalyst while preventing problems that occur, like clogging of an exhaust gas recirculation passage.

Abstract: An engine where first combustion where the amount of the EGR gas in the combustion chamber is larger than the amount of EGR where the amount of production of soot peaks and a second combustion where the amount of EGR gas in the combustion chamber is smaller than the amount of EGR gas where the amount of production of soot peaks are selectively switched between and where an NOx absorbent is placed in the exhaust passage of the engine. When SOx should be released from the NOx absorbent, the first combustion is performed under a rich air-fuel ratio, while when the second combustion is performed, auxiliary fuel is injected during the first part of the suction stroke or the expansion stroke and the injection timing of the main fuel is delayed by a large extent.

Abstract: A first combustion mode in which an amount of an EGR gas within a combustion chamber is higher than that of the EGR gas when a generated amount of soot reaches a peak and substantially no soot is generated. A second combustion mode in which the amount of the EGR gas within the combustion chamber is lower than that of the EGR gas when the generated amount of soot reaches the peak are selectively performed. A catalyst is disposed within an engine exhaust passage wherein a temperature of the catalyst is adjusted so as to be within a predetermined range.

Abstract: According to the present invention, there is provided an exhaust gas purification device, comprising a NOx absorbent arranged in an exhaust passage of an engine for absorbing NOx therein when an air-fuel ratio of an exhaust gas flowing into the NOx absorbent is lean, the NOx absorbent discharging NOx absorbed therein when a concentration of the oxygen in the exhaust gas flowing into the NOx absorbent decreases, a trapping element arranged in the exhaust passage upstream of the NOx absorbent for trapping particulates, a processing element for processing the particulates trapped in the trapping element to regenerate the trapping element, and a preventing element for preventing the exhaust gas from flowing into the NOx absorbent from the trapping element when the trapping element is regenerated.

Abstract: An internal combustion engine system is capable of reducing soot and NOx simultaneously, and prevents the occurrence of an undesirable situation where a generation amount of soot is increased in accordance with frequent transitions between a first combustion mode and a second combustion mode. In the system, the first combustion mode in which an amount of inert gas supplied to the combustion chamber is larger than an amount of the inert gas that causes the generation amount of soot to become a peak, such that soot is hardly generated, and a second combustion mode in which an amount of the inert gas supplied to the combustion chamber is smaller than the amount of the inert gas that causes the generation amount of soot to become a peak, are selectively performed. When conditions are such that switching between the first combustion mode and the second combustion mode has or may occur frequently, the execution of the first combustion mode is controlled.

Abstract: A stable combustion without generating smoke or misfire is performed by selectively conducting a first combustion mode and a second combustion mode. In the first combustion mode, an amount of an inert gas, e.g., EGR gas, provided to a combustion chamber is made to be larger than an amount of the inert gas that causes the generation amount of soot to become a peak amount. This causes substantially no soot to be generated. In the second combustion mode, the amount of the inert gas provided to the combustion chamber is made to be smaller than the amount that causes the generation amount of soot to become a peak amount. The injection timing is quickened if the injection amount is increased in the first combustion mode, and the injection timing is delayed if the injection amount is reduced.

Abstract: In an exhaust gas purification device, a catalytic converter containing selective reduction catalysts is disposed in an exhaust gas passage of an internal combustion engine capable of being operated at a lean air-fuel ratio. The catalytic converter includes a plurality of the selective reduction catalysts disposed in series in the casing of the catalytic converter. Bypass passages which supply the exhaust gas to downstream selective reduction catalysts in the casing by bypassing the upstream catalysts are provided. When a reducing agent is supplied to the exhaust gas upstream of the converter, a part of the supplied reducing agent directly reaches the downstream selective reduction catalyst through the bypass passages without being oxidized by the upstream selective reduction catalysts. Therefore, the NOx purifying abilities of the downstream catalysts are improved and the formation of sulfates on the downstream catalysts is suppressed.

Abstract: A mean vehicle speed Va and a mean variation .DELTA.Va are factors reflecting a current driving condition and an expected driving condition of a vehicle, which relate to a charge-discharge amount of a battery. A target state SOC* of the battery is calculated from the mean vehicle speed Va and the mean variation .DELTA.Va. The charge-discharge amount of the battery increases with an increase in mean vehicle speed Va and mean variation .DELTA.Va. The lower charging state of the battery results in the higher charge-discharge efficiency. The structure of the present invention sets the target state SOC* of the battery and controls the actual state of the battery to the target state SOC*, thereby enhancing the charge-discharge efficiency of the battery and ensuring a sufficient supply of electric power required for driving the vehicle.