Abstract: There are provided a control system and method and an engine control unit for an internal combustion engine including two types of variable valve mechanisms capable of changing a camp phase and a cam profile, respectively, which system is capable of determining an amount of fuel to be injected as a value suited to charging efficiency at the time by simplified calculation processing, thereby performing the fuel injection control properly in a simplified manner. The fuel injection control system includes an ECU. The ECU searches a map for a multiplier term Ati for a high-speed cam or low-speed cam based on the rotational speed of the engine and the cam phase, and a map for an addend term Bti for the high-speed cam or the low-speed cam based on the rotational speed of the engine and the cam phase. The ECU calculates a basic fuel injection time period Tibase as the sum of the product of an intake pipe absolute pressure PBA and the multiplier term Ati and the addend term Bti (Ati×PBA+Bti).

Abstract: A controller for an internal combustion engine detects a demand variable showing a demand from a driver, and controls an intake air volume to the internal combustion engine according to the detected demand variable. When trouble is detected in a system controlling the intake air volume, the controller switches a driving control of a vehicle to a emergency driving mode. In the emergency driving mode, the controller keeps the intake air volume to the internal combustion engine constant. The controller calculates a emergency driving control variable according to the detected demand variable, and controls the driving of the vehicle according to the calculated emergency driving control variable. The emergency driving control variable is a control variable different from the intake air volume. Thus, in the emergency driving mode, the driving of the vehicle can be controlled by the control variable different from the intake air volume, and a better drivability is ensured.

Abstract: There is disclosed a fuel injection control system for an internal combustion engine, which is capable of properly determining fuel injection timing such that the fuel injection timing reflects behaviors of injected fuel, thereby improving drivability and fuel economy. The internal combustion engine of an in-cylinder fuel injection type is operated while switching between a stratified combustion mode in which fuel injection into each cylinder is performed during a compression stroke and a homogenous combustion mode in which the fuel injection into the cylinder is performed during an intake stroke. The fuel injection control system controls fuel injection timing. A required fuel injection time is determined based on detected operating conditions of the engine. A direct ratio and a carry-off ratio are determined based on the operating conditions of the engine.

Abstract: A control system for a direct injection spark ignition engine connected to an automatic transmission that modifies engine power in accordance with a selected one of shift programs (a normal mode for improved fuel economy and a power mode for improved performance). A torque required by the engine is determined based on the detected engine speed and the engine load in accordance with characteristics corresponding to the selected shift program. And, an engine operation mode is determined to one of three modes including a stoichiometric air/fuel ratio operation mode in which a desired air/fuel ratio is set to a stoichiometric air/fuel ratio and two lean-bum operations mode in which the desired air/fuel ratio is set to be leaner than the stoichiometric air/fuel ratio. The desired air/fuel ratio is used to correct the fuel injection amount to be supplied to the engine.

Abstract: There is provided a control system for an internal combustion engine which controls the operation of the engine such that the combustion mode of the engine is switched between a stratified combustion mode and a homogeneous combustion mode, and torque generated by the engines is controlled based on a desired torque. The control system has an ECU which calculates a required torque based on results of detection by a crack angle position sensor and an accelerator pedal sensor, and determines a combustion mode according to the required torque. Further, the ECU smoothes the required torque in dependence on the combustion mode, to thereby calculate a smoothed required torque. Then, ECU sets the desired torque based on the smoothed required torque.

Abstract: There are provided a control system and method and an engine control unit for an internal combustion engine including two types of variable valve mechanisms capable of changing a camp phase and a cam profile, respectively, which system is capable of determining an amount of fuel to be injected as a value suited to charging efficiency at the time by simplified calculation processing, thereby performing the fuel injection control properly in a simplified manner. The fuel injection control system includes an ECU. The ECU searches a map for a multiplier term Ati for a high-speed cam or low-speed cam based on the rotational speed of the engine and the cam phase, and a map for an addend term Bti for the high-speed cam or the low-speed cam based on the rotational speed of the engine and the cam phase. The ECU calculates a basic fuel injection time period Tibase as the sum of the product of an intake pipe absolute pressure PBA and the multiplier term Ati and the addend term Bti (Ati×PBA+Bti).

Abstract: Control system for an internal combustion engine, for setting a desired torque in response to operating conditions of the engine and controlling torque based on the set desired torque. A crank angle position sensor detects an engine rotational speed. An accelerator position sensor detects an accelerator position. A required torque is calculated based on results of detection by the crank angle position sensor and the accelerator position sensor. Further, the calculated required torque is smoothed. Then, the present value of the required torque calculated at the present time and the smoothed required torque are compared with each other. When it is determined that the engine is being accelerated, an acceleration assist amount is calculated based on a difference value between the present value of the required torque and the smoothed required torque. Then, the acceleration assist amount is added to the smoothed required torque, whereby the desired torque is set.

Abstract: An ignition time controller for an internal combustion engine is provided for setting an ignition time such that it can rapidly converge to an appropriate value in accordance with a change in intake characteristics associated with a change in cam phase in either of a uniform combustion mode and a stratified combustion mode in a direct injection type internal combustion engine having a cam phase changing mechanism.

Abstract: A valve timing controller for use in a direct injection type internal combustion engine is provided for enabling a valve timing to be appropriately set in accordance with a load on the engine even in a stratified combustion mode. The internal combustion engine has a valve timing changing mechanism for changing a valve timing of at least one of an intake valve and an exhaust valve so that it is operated in a combustion mode switched between a uniform combustion mode in which a fuel is injected into a cylinder during an intake stroke and a stratified combustion mode in which a fuel is injected into a cylinder in a compression stroke. The valve timing controller comprises a required torque determining unit for determining a required torque outputted by the internal combustion engine based on the engine rotational speed and accelerator pedal opening, and a valve timing determining unit for determining the valve timing in accordance with the required torque and the engine rotational speed.

Abstract: In a direct injection spark ignition engine which is operable in lean-burn operation modes including a pre-mixture combustion mode and a stratified combustion operation mode and a stoichiometric air/fuel ratio operation mode, which are different in the desired air/fuel ratio. The degradation of combustion state is detected through misfire detection and if it is determined to be degraded, the desired air/fuel ratio, the EGR flow rate and the ignition timing are changed when the engine is operated in the stratified combustion operation mode, while the desired air/fuel ratio, the EGR flow rate and the purge flow rate are changed when the engine is operated in the pre-mixture combustion operation mode, thereby ensuring to suppress the combustion state degradation effectively.

Abstract: In a direct injection spark ignition engine which is operable in three operation modes including a stoichiometric air/fuel ratio operation mode, a pre-mixture combustion mode and a stratified combustion operation mode which are different in the desired air/fuel ratio and a single air/fuel ratio sensor installed downstream of the exhaust manifold, the sensor output is successively sampled and one from among the sampled data is selected based on the engine speed and engine load and selected one of the operation modes such that the air/fuel ratio at each cylinder can be accurately estimated for the selected operation mode under the engine operating conditions.

Abstract: There are provided a control system and method and an engine control unit for an internal combustion engine, which are capable of properly determining an amount of fuel to be injected during a two-stage fuel injection combustion mode and a duration period of this mode such that stable combustion and smooth transition between combustion modes are ensured, thereby attaining excellent drivability and fuel economy. The combustion mode of the engine is switched between a homogeneous combustion mode in which fuel injection into each cylinder is performed during an intake stroke, a stratified combustion mode in which the fuel injection into the cylinder is performed during a compression stroke, and the two-stage fuel injection combustion mode in which the fuel injection into the cylinder is performed once during the intake stroke and once during the compression stroke during transition between the homogeneous combustion mode and the stratified combustion mode.

Abstract: A controller for an internal combustion engine detects a demand variable showing a demand from a driver, and controls an intake air volume to the internal combustion engine according to the detected demand variable. When trouble is detected in a system controlling the intake air volume, the controller switches a driving control of a vehicle to a emergency driving mode. In the emergency driving mode, the controller keeps the intake air volume to the internal combustion engine constant. The controller calculates a emergency driving control variable according to the detected demand variable, and controls the driving of the vehicle according to the calculated emergency driving control variable. The emergency driving control variable is a control variable different from the intake air volume. Thus, in the emergency driving mode, the driving of the vehicle can be controlled by the control variable different from the intake air volume, and a better drivability is ensured.

Abstract: There are provided a control system and method and an engine control unit for an internal combustion engine, which are capable of attaining a high combustion efficiency in both of a homogenous and a stratified combustion modes, thereby improving drivability and fuel economy, as well as a control system for an internal combustion engine which is capable of ensuring stable combustion in both the modes. In one form of the invention, the control system includes an ECU for controlling ignition timing IG of an in-cylinder fuel injection type engine which is operated while switching the combustion mode between the homogeneous and stratified combustion modes. The ECU determines which of the homogeneous and stratified combustion modes should be selected.

Abstract: There is disclosed a fuel injection control system for an in-cylinder fuel injection internal combustion engine, which is capable of properly determining a fuel injection time period such that the fuel injection time period reflects a fuel pressure and a deposition of fuel, thereby controlling the amount of fuel to be actually injected. Operating conditions of the engine are detected, and a required fuel amount is determined based on the detected operating conditions. At the same time, a deposited-fuel amount, i.e. an amount of fuel deposited in a combustion chamber, is determined based on the detected operating conditions, and the required fuel amount is corrected according to the determined deposited-fuel amount. Further, a fuel pressure of fuel to be injected into the cylinder is detected, and the fuel injection time period is determined by correcting the corrected required fuel amount according to the detected fuel pressure.

Abstract: There is disclosed a fuel injection control system for an internal combustion engine, which is capable of properly determining fuel injection timing such that the fuel injection timing reflects behaviors of injected fuel, thereby improving drivability and fuel economy. The internal combustion engine of an in-cylinder fuel injection type is operated while switching between a stratified combustion mode in which fuel injection into each cylinder is performed during a compression stroke and a homogenous combustion mode in which the fuel injection into the cylinder is performed during an intake stroke. The fuel injection control system controls fuel injection timing. A required fuel injection time is determined based on detected operating conditions of the engine. A direct ratio and a carry-off ratio are determined based on the operating conditions of the engine.

Abstract: A composite catalyst includes a first catalyst part containing an Ir catalyst and a second catalyst part covering the first catalyst part and containing a perovskite type composite oxide. The perovskite type composite oxide contributes mainly to oxidation reaction such as NO+O2→NO2 in an atmosphere of excess oxygen while the Ir catalyst contributes mainly to reduction reaction with HC (hydrocarbon) as a reducing agent such as NO2+HC+O2→N2+CO2+H2O.

Abstract: A system for purifying exhaust gas of an internal combustion engine having a catalyst in an exhaust system of the engine, said catalyst reducing nitrogen oxide when exhaust gas generated by the engine is in an oxidizing state. An EGR mechanism is provided for recirculating a part of the exhaust gas to an intake system of the engine, and is controlled such that a ratio of unsaturated and/or aromatic hydrocarbon concentration to nitrogen oxide concentration in the exhaust gas is at or above a predetermined value. The EGR mechanism is further controlled such that oxygen concentration in the exhaust gas is below a prescribed value. An injection timing mechanism is controlled for the same purpose. With this arrangement, the system improves the NOx purification rate of the catalyst.

Abstract: An engine exhaust gas purification system having a catalyst in an exhaust system of the engine, said catalyst reducing nitrogen oxide when exhaust gas generated by the engine is in an oxidizing state. In the system, engine operating parameters, including at least an engine speed and an engine load, are determined and catalyst temperature is determined, and air/fuel ratio is controlled in response to the detected parameters and the determined catalyst temperature, thereby enabling the catalyst to purify NOx in its optimum temperature characteristic range to achieve enhanced NOx constituent purification performance in an oxidizing environment. Alternatively, the air/fuel ratio is controlled in the stoichiometric or richer direction when the catalyst temperature is high, thereby protecting the catalyst from being damaged. The catalyst is a selective-reduction type nitrogen oxide reduction catalyst.

Abstract: A control system for an internal combustion engine having a plurality of cylinders each having at least one intake valve, at least one exhaust valve, and a crankshaft. The control system has an electromagnetic driving section which electromagnetically causes opening and closing of at least one of the at least one intake valve and the at least one exhaust valve. A crank angle sensor generates a crank angle signal whenever the crankshaft rotates through a predetermined angle, and a cylinder position sensor generates a cylinder-discriminating signal indicative of a predetermined crank angle of a particular cylinder of a plurality of the cylinders. A piston position sensor detects an operating state or position of the piston of each of the plurality of the cylinders, based on the generated crank angle signal and the generated cylinder-discriminating signal.