Abstract: A control device for an internal combustion engine includes a throttle valve actuator and circuitry. The circuitry is configured to calculate, based on a target intake air amount, a target recirculated amount of recirculated exhaust gas that is recirculated to an intake passage through an exhaust gas recirculation device, calculate a corrected target recirculated amount based on the target recirculated amount and an exhaust gas recirculated amount change delay in a change in a recirculated amount of the recirculated exhaust gas, calculate a target intake pressure based on the target intake air amount and the corrected target recirculated amount, calculate a target opening degree of the throttle valve based on the target intake air amount and the target intake pressure, and control the throttle valve actuator to drive the throttle valve such that an opening degree of the throttle valve is to be equal to the target opening degree.

Abstract: A fuel injection control method for an internal combustion engine includes instantaneous injection that injects fuel to a predetermined cylinder is executed immediately when it is determined that a predetermined condition is satisfied after cranking of the engine is started. A leaning influence ratio which is a ratio of a time period during which vaporized fuel supplied to the predetermined cylinder becomes lean to a instantaneous injection time period which is a time period over which fuel is injected by the instantaneous injection is estimated. A threshold value is set based on temperature of the engine. When the leaning influence ratio is larger than the threshold value, the instantaneous injection is inhibited.

Abstract: A fuel injection control method for an internal combustion engine includes instantaneous injection that injects fuel to a predetermined cylinder is executed immediately when it is determined that a predetermined condition is satisfied after cranking of the engine is started. A leaning influence ratio which is a ratio of a time period during which vaporized fuel supplied to the predetermined cylinder becomes lean to a instantaneous injection time period which is a time period over which fuel is injected by the instantaneous injection is estimated. A threshold value is set based on temperature of the engine. When the leaning influence ratio is larger than the threshold value, the instantaneous injection is inhibited.

Abstract: A control for an internal combustion engine having a fuel injection valve for directly injecting fuel to a combustion chamber of the engine, an ignition device for burning an air-fuel mixture containing the fuel injected from the fuel injection valve, and a variable cylinder management mechanism that is capable of changing the number of operating cylinders is provided. The control includes making a transition to an operating mode where the number of operating cylinders is decreased through the variable cylinder management mechanism. It is predicted based on an operating condition of the engine that an air-fuel ratio of an exhaust atmosphere of the engine becomes lean due to a stop of the fuel injection into one or more cylinders to be halted by the transition.

Abstract: A control system for an internal combustion engine is provided. In the control system, a target intake air amount is calculated according to a target output torque of the engine, and an intake air amount of the engine is controlled according to the target intake air amount. An ignition timing of the engine is controlled.

Abstract: In an intake system comprising a first intake passage (1) having an upstream end communicating with an intake duct (3) and a downstream end communicating with an intake port of an engine cylinder, a first intake control valve (6) provided in the first intake passage, a second intake passage (2) having an upstream end communicating with the intake duct and a downstream end communicating with the intake port of the engine cylinder, a second intake control valve (7) provided in the second intake passage, an accelerator pedal(ACL) and a control unit (100) for controlling opening angles of the first and second intake control valves, the second intake control valve is opened when the first intake control valve has opened to an effective opening angle and an intake air flow rate is required to be further increased.

Abstract: A fuel injection control system for an internal combustion engine, which is capable of properly performing instantaneous injection, thereby capable of attaining excellent exhaust emissions at the start of the engine, and performing prompt engine starting. In the fuel injection control system, the instantaneous injection that injects fuel to a predetermined cylinder is executed immediately when it is determined that a predetermined condition is satisfied after cranking of the engine is started. A leaning influence ratio which is a ratio of a time period during which vaporized fuel supplied to the predetermined cylinder becomes lean to a instantaneous injection time period which is a time period over which fuel is injected by the instantaneous injection is estimated. A threshold value is set based on temperature of the engine. When the leaning influence ratio is larger than the threshold value, the instantaneous injection is inhibited.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism for halting operation of at least one of the plurality of cylinders by stopping operation of at lease one intake valve of the at least one cylinder. The control system includes an intake air control valve for controlling an amount of air supplied to the engine. An opening of the intake air control valve is changed when performing an increase in a number of operating cylinders in an idling condition of the engine. A basic opening of the intake air control valve is switched from a first basic opening corresponding to the number of operating cylinders before the increase in the number of operating cylinders to a second basic opening corresponding to the number of operating cylinders after the increase in the number of the operating cylinders. The basic opening is corrected in the closing direction during a predetermined time period when increasing the number of operating cylinders.

Abstract: In an intake system comprising a first intake passage (1) having an upstream end communicating with an intake duct (3) and a downstream end communicating with an intake port of an engine cylinder, a first intake control valve (6) provided in the first intake passage, a second intake passage (2) having an upstream end communicating with the intake duct and a downstream end communicating with the intake port of the engine cylinder, a second intake control valve (7) provided in the second intake passage, an accelerator pedal (ACL) and a control unit (100) for controlling opening angles of the first and second intake control valves, the second intake control valve is opened when the first intake control valve has opened to an effective opening angle and an intake air flow rate is required to be further increased.

Abstract: A control system for an internal combustion engine is provided. In the control system, a target intake air amount is calculated according to a target output torque of the engine, and an intake air amount of the engine is controlled according to the target intake air amount. An ignition timing of the engine is controlled.

Abstract: A control system for an internal combustion engine having a plurality of cylinders and a cylinder halting mechanism for halting operation of at least one of the plurality of cylinders by stopping operation of at lease one intake valve of the at least one cylinder. The control system includes an intake air control valve for controlling an amount of air supplied to the engine. An opening of the intake air control valve is changed when performing an increase in a number of operating cylinders in an idling condition of the engine. A basic opening of the intake air control valve is switched from a first basic opening corresponding to the number of operating cylinders before the increase in the number of operating cylinders to a second basic opening corresponding to the number of operating cylinders after the increase in the number of the operating cylinders. The basic opening is corrected in the closing direction during a predetermined time period when increasing the number of operating cylinders.

Abstract: A control for an internal combustion engine having a fuel injection valve for directly injecting fuel to a combustion chamber of the engine, an ignition device for burning an air-fuel mixture containing the fuel injected from the fuel injection valve, and a variable cylinder management mechanism that is capable of changing the number of operating cylinders is provided. The control includes making a transition to an operating mode where the number of operating cylinders is decreased through the variable cylinder management mechanism. It is predicted based on an operating condition of the engine that an air-fuel ratio of an exhaust atmosphere of the engine becomes lean due to a stop of the fuel injection into one or more cylinders to be halted by the transition.

Abstract: A controller for cylinder cut-off for a multi-cylinder internal combustion engine including a partially operable cylinder that can be cutoff by a cut-off cylinder mechanism provided therewith and a full operating cylinder that is not cut off, the controller for cylinder cut-off including a partially operable cylinder side catalyst temperature estimating section, a full operating cylinder side catalyst temperature estimating section, and a cylinder cut-off authorization determining section for determining whether to authorize or prohibit a cut-off of the partially operable cylinder based on a partially operable cylinder side catalyst temperature estimated by the partially operable cylinder side catalyst temperature estimating section: and a full operating cylinder side catalyst temperature estimated by the full operating cylinder side catalyst temperature estimating section.

Abstract: There is provided an ignition timing control system for a variable-cylinder internal combustion engine, which is capable of optimally reducing torque before the start of fuel cut-off operation, irrespective of whether the engine is in an all-cylinder operation mode or a partial-cylinder operation mode, thereby reducing shock caused by the fuel cut-off operation. When the internal combustion engine is operated under deceleration operating conditions, the start of cut-off of fuel supply is delayed for a predetermined time period, and ignition timing is corrected when the cut-off of fuel supply is being delayed for the predetermined time period. The amount of correction of the ignition timing is set to a different value depending on the operation mode.

Abstract: A controller for cylinder cut-off for a multi-cylinder internal combustion engine including a partially operable cylinder that can be cutoff by a cut-off cylinder mechanism provided therewith and a full operating cylinder that is not cut off, the controller for cylinder cut-off including a partially operable cylinder side catalyst temperature estimating section, a full operating cylinder side catalyst temperature estimating section, and a cylinder cut-off authorization determining section for determining whether to authorize or prohibit a cut-off of the partially operable cylinder based on a partially operable cylinder side catalyst temperature estimated by the partially operable cylinder side catalyst temperature estimating section: and a full operating cylinder side catalyst temperature estimated by the full operating cylinder side catalyst temperature estimating section.

Abstract: An ignition timing control apparatus for an internal combustion engine having a plurality of cylinders, wherein operation of the engine is switchable between a partial-cylinder operation, which operates some of the cylinders, and an all-cylinder operation, which operates all of the cylinders. Basic ignition timing is calculated according to an operating condition of the engine. Knocking is determined based on an output of the knock sensor. A correction amount of the ignition timing is calculated according to a result of the knocking determination to suppress knocking, and the basic ignition timing is corrected with the calculated correction amount. Learning values of the correction amount are calculated corresponding, respectively, to partial-cylinder operation and all-cylinder operation, and one of the calculated learning values is used according to the operating condition of the engine.

Abstract: There is provided an ignition timing control system for a variable-cylinder internal combustion engine, which is capable of optimally reducing torque before the start of fuel cut-off operation, irrespective of whether the engine is in an all-cylinder operation mode or a partial-cylinder operation mode, thereby reducing shock caused by the fuel cut-off operation. When the internal combustion engine is operated under deceleration operating conditions, the start of cut-off of fuel supply is delayed for a predetermined time period, and ignition timing is corrected when the cut-off of fuel supply is being delayed for the predetermined time period. The amount of correction of the ignition timing is set to a different value depending on the operation mode.

Abstract: An ignition timing control apparatus for an internal combustion engine having a plurality of cylinders, wherein operation of the engine is switchable between a partial-cylinder operation, which operates some of the cylinders, and an all-cylinder operation, which operates all of the cylinders. Basic ignition timing is calculated according to an operating condition of the engine. Knocking is determined based on an output of the knock sensor. A correction amount of the ignition timing is calculated according to a result of the knocking determination to suppress knocking, and the basic ignition timing is corrected with the calculated correction amount. Learning values of the correction amount are calculated corresponding, respectively, to partial-cylinder operation and all-cylinder operation, and one of the calculated learning values is used according to the operating condition of the engine.