Abstract: A control apparatus for an internal combustion engine includes phase change means (60) for advancing or retarding phases of an opening timing and a closing timing of an intake valve (62); duration change means (60) for increasing or decreasing a duration of the intake valve (62); and EGR gas amount increase means (50) for increasing an amount of EGR gas, based on an operating state of an internal combustion engine. The control apparatus further includes intake-valve closing timing advancing means (50) for advancing the intake-valve closing timing when the amount of EGR gas is increased. The intake-valve closing timing advancing means (50) advances the intake-valve closing timing by performing a first operation that advances the phases using the phase change means (60), and performing a second operation that decreases the duration using the duration change means (60), and makes a timing at which the second operation is started later than a timing at which the first operation is started.

Abstract: Disclosed is a technology that enables better reduction of NOx stored in an NOx catalyst in an exhaust gas purification system for an internal combustion engine. When NOx stored in an NOx catalyst is to be reduced, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to a target air-fuel ratio by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine. In doing so, if the temperature of the NOx catalyst is not lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to the target air-fuel ratio while bringing the combustion state into low temperature combustion.

Abstract: An object of the present invention is to provide a technology that enables reduction of NOx stored in an NOx catalyst with improved efficiency in an exhaust gas purification system for an internal combustion engine. According to the present invention, when NOx stored in the NOx catalyst is to be reduced, if the temperature of the NOx catalyst is lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased only by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine, and if the temperature of the NOx catalyst is not lower than the specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased either only by adding reducing agent through reducing agent addition means, or by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine and adding reducing agent through the reducing agent addition means.

Abstract: A control apparatus for an internal combustion engine (10) includes intake valve control means (50). The internal combustion engine (10) includes a variable intake valve operating mechanism (66) that changes a valve opening characteristic of an intake valve (64), and rich combustion is performed in the internal combustion engine (10) to control an exhaust gas purification catalyst (24) disposed in an exhaust passage (18). The intake valve control means (50) controls the valve opening characteristic of the intake valve (64) to increase a flow rate of intake air in an early stage of an intake stroke when the rich combustion is performed, as compared to when non-rich combustion is performed.

Abstract: During a rich spike control for an exhaust gas purification system for an internal combustion engine, a base air-fuel ratio AFb is decreased in a range where a combustion variation ?CC does not exceed a permissible limit ?CCL (S108). When the combustion variation ?CC exceeds the permissible limit ?CCL, the spike base air-fuel ratio AFbs is increased (S213). When the torque decrease amount ?TD is above the permissible value ?TDL, the spike base air-fuel ratio AFbs is decreased (S215). When the combustion variation ?CC is above the permissible limit ?CCL, and the torque decrease amount ?TD is above the permissible value ?TDL, the spike base air-fuel ratio AFbs is increased, and a fuel discharge time number EN is increased (S216).

Abstract: A control apparatus for an internal combustion engine, which can generate exhaust pressure pulsation at an early period while suppressing the degradation of volumetric efficiency, when a request to enhance the exhaust pressure pulsation is made in the internal combustion engine which includes a variable valve mechanism that makes variable a valve overlap period, and a variable nozzle type turbocharger.

Abstract: An internal combustion engine control apparatus that prevents an abrupt change in the air amount at the time of supercharger switching. The control apparatus enters a small turbo operating state in which a small turbocharger is mainly operative, during relatively low-rotation-speed and low-load side, and enters a large turbo operating state in which a large turbocharger is mainly operative, in a relatively high-rotation-speed and high-load. In the small turbo operating state, the control apparatus can exercise charging efficiency enhancement control by using a scavenging effect. Before switching from the small turbo operating state to the large turbo operating state, the control apparatus predicts whether the large turbocharger will build up its boost pressure quickly or slowly. When slow boost pressure is predicted, the control apparatus exercises charging efficiency enhancement control to provide a low degree of charging efficiency enhancement.

Abstract: Fuel pipes guide fuel from a fuel tank provided in a rear area of the vehicle to a low-pressure fuel supply system and a high-pressure fuel supply system, respectively, for injecting the fuel to an engine provided in a front area of the vehicle. A branch point between the fuel pipes is arranged in the vicinity of the fuel tank to secure a long pipe length between the low-pressure fuel supply system and the high-pressure fuel supply system. This can suppress variation in fuel pressure at the low-pressure fuel supply system attributable to the fuel that is discharged from the high-pressure fuel pump within the high-pressure fuel supply system back to the fuel pipe.

Abstract: An internal combustion engine control apparatus that prevents an abrupt change in the air amount at the time of supercharger switching. The control apparatus enters a small turbo operating state in which a small turbocharger is mainly operative, during relatively low-rotation-speed and low-load side, and enters a large turbo operating state in which a large turbocharger is mainly operative, in a relatively high-rotation-speed and high-load. In the small turbo operating state, the control apparatus can exercise charging efficiency enhancement control by using a scavenging effect. Before switching from the small turbo operating state to the large turbo operating state, the control apparatus predicts whether the large turbocharger will build up its boost pressure quickly or slowly. When slow boost pressure is predicted, the control apparatus exercises charging efficiency enhancement control to provide a low degree of charging efficiency enhancement.

Abstract: An object of the present invention is to provide a technology that enables reduction of NOx stored in an NOx catalyst with improved efficiency in an exhaust gas purification system for an internal combustion engine. According to the present invention, when NOx stored in the NOx catalyst is to be reduced, if the temperature of the NOx catalyst is lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased only by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine, and if the temperature of the NOx catalyst is not lower than the specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased either only by adding reducing agent through reducing agent addition means, or by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine and adding reducing agent through the reducing agent addition means.

Abstract: A control apparatus for an internal combustion engine, which can generate exhaust pressure pulsation at an early period while suppressing the degradation of volumetric efficiency, when a request to enhance the exhaust pressure pulsation is made in the internal combustion engine which includes a variable valve mechanism that makes variable a valve overlap period, and a variable nozzle type turbocharger.

Abstract: Disclosed is a technology that enables better reduction of NOx stored in an NOx catalyst in an exhaust gas purification system for an internal combustion engine. When NOx stored in an NOx catalyst is to be reduced, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to a target air-fuel ratio by decreasing the air-fuel ratio of the exhaust gas discharged from the internal combustion engine. In doing so, if the temperature of the NOx catalyst is not lower than a specific temperature, the air-fuel ratio of the ambient atmosphere around the NOx catalyst is decreased to the target air-fuel ratio while bringing the combustion state into low temperature combustion.

Abstract: A control apparatus for an internal combustion engine (10) includes intake valve control means (50). The internal combustion engine (10) includes a variable intake valve operating mechanism (66) that changes a valve opening characteristic of an intake valve (64), and rich combustion is performed in the internal combustion engine (10) to control an exhaust gas purification catalyst (24) disposed in an exhaust passage (18). The intake valve control means (50) controls the valve opening characteristic of the intake valve (64) to increase a flow rate of intake air in an early stage of an intake stroke when the rich combustion is performed, as compared to when non-rich combustion is performed.

Abstract: A control apparatus for an internal combustion engine includes phase change means (60) for advancing or retarding phases of an opening timing and a closing timing of an intake valve (62); duration change means (60) for increasing or decreasing a duration of the intake valve (62); and EGR gas amount increase means (50) for increasing an amount of EGR gas, based on an operating state of an internal combustion engine. The control apparatus further includes intake-valve closing timing advancing means (50) for advancing the intake-valve closing timing when the amount of EGR gas is increased. The intake-valve closing timing advancing means (50) advances the intake-valve closing timing by performing a first operation that advances the phases using the phase change means (60), and performing a second operation that decreases the duration using the duration change means (60), and makes a timing at which the second operation is started later than a timing at which the first operation is started.

Abstract: During a rich spike control for an exhaust gas purification system for an internal combustion engine, a base air-fuel ratio AFb is decreased in a range where a combustion variation ?CC does not exceed a permissible limit ?CCL (S108). When the combustion variation ?CC exceeds the permissible limit ?CCL, the spike base air-fuel ratio AFbs is increased (S213). When the torque decrease amount ?TD is above the permissible value ?TDL, the spike base air-fuel ratio AFbs is decreased (S215). When the combustion variation ?CC is above the permissible limit ?CCL, and the torque decrease amount ?TD is above the permissible value ?TDL, the spike base air-fuel ratio AFbs is increased, and a fuel discharge time number EN is increased (S216).

Abstract: The present invention relates to a control apparatus for an internal combustion engine. An object of the present invention is to suppress deterioration of emission and fuel consumption arising during acceleration due to an effect of an exhaust valve opening timing. An upper limit of a fuel injection quantity is set based on the exhaust valve opening timing. The fuel injection quantity is limited to the upper limit or less when the fuel injection quantity is increased during acceleration. The exhaust valve opening timing at which the upper limit is maximized is set to a relatively advanced timing in a low engine speed range, moving in the retard direction as the engine speed rises from the low engine speed range toward a mid engine speed range, and moving in the advance direction as the engine speed rises further from the mid engine speed range toward a high engine speed range.

Abstract: An electrically driven type low-pressure fuel pump whose flow rate can be set draws fuel from a fuel tank and discharges it at a prescribed pressure commonly to a low-pressure fuel supply system including intake manifold injectors and a low-pressure delivery pipe and to a high-pressure fuel supply system including in-cylinder injectors, a high-pressure delivery pipe and a high-pressure fuel pump. The discharge flow rate of the low-pressure fuel pump is set based on required supply quantities to the low-pressure fuel supply system and to the high-pressure fuel supply system obtained according to the engine operation conditions. The discharge quantity of the fuel pump in the internal combustion engine can be set as appropriate, and thus, deterioration in fuel efficiency due to excessive flow rate setting and operation failure due to insufficient fuel supply can be prevented, whereby reliability is improved.

Abstract: A dual-injector fuel injection engine includes a cylinder block, a cylinder head, an intake port, an intake manifold, a surge tank, an in-cylinder injector, an intake pipe injector, and first and second delivery pipes. The in-cylinder injector is positioned below the intake port, when seen from an axial direction of a crank shaft, and attached to the cylinder head. The intake pipe injector and the second delivery pipe are supported above the intake port, when seen from the axial direction of the crank shaft, by the intake manifold to be close to the intake port.

Abstract: A low-pressure fuel supply system for applying pressure to a fuel by using a feed pump and supplying the fuel to a manifold fuel injection mechanism, and a high-pressure fuel supply system branched from the low-pressure fuel supply system and for applying pressure to the low-pressure fuel by using a high-pressure pump of a metering delivery type driven in accordance with the engine operation state and supplying the resultant fuel to an in-cylinder fuel injection mechanism are provided. The high-pressure pump supplies all the pressurized fuel to the high-pressure fuel supply system, irrespective of an actuation state of the in-cylinder fuel injection mechanism. Excessive fuel is returned when a relief valve is opened. Thus, pulsation caused by operation of the high-pressure pump is reduced, and the fuel can be supplied in a proper quantity.

Abstract: A dual-injector fuel injection engine includes a cylinder block, a cylinder head, an intake port, an intake manifold, a surge tank, an in-cylinder injector, an intake pipe injector, and first and second delivery pipes. The in-cylinder injector is positioned below the intake port, when seen from an axial direction of a crank shaft, and attached to the cylinder head. The intake pipe injector and the second delivery pipe are supported above the intake port, when seen from the axial direction of the crank shaft, by the intake manifold to be close to the intake port.