Abstract: An ambient NOx adsorption catalyst that can adsorb NOx contained in an exhaust gas in the presence of CO under standard conditions is placed in an engine exhaust gas passage, in an internal combustion engine. Until an engine post-initiation catalyst is activated, the amounts of a high-boiling-point hydrocarbon and an unsaturated hydrocarbon that are contained in the exhaust gas flowing into the catalyst are reduced so that the NOx-adsorbing activity cannot be deteriorated by the adhesion activity of the hydrocarbons while maintaining the CO concentration in the exhaust gas flowing into the catalyst at a level higher than the concentration required for the adsorption of NOx.

Abstract: A control apparatus for an internal combustion engine that can prevent, for instance, an exhaust purification catalyst from being damaged when the employed fuel is changed to a fuel having different properties during an operation. If fuel learning is incomplete while a refueling record exists, the throttle opening of an internal combustion engine operable on a fuel that is obtained by mixing alcohol and gasoline at an arbitrary ratio is limited. Limiting the throttle opening makes it possible to avoid an entry into an operation region where fuel increase is performed. This prevents air-fuel ratio feedback control from being stopped when a fuel change occurs. Consequently, the use of an improper air-fuel ratio that may damage the catalyst can be definitely avoided.

Abstract: An ambient NOx adsorption catalyst that can adsorb NOx contained in an exhaust gas in the presence of CO under standard conditions is placed in an engine exhaust gas passage, in an internal combustion engine. Until an engine post-initiation catalyst is activated, the amounts of a high-boiling-point hydrocarbon and an unsaturated hydrocarbon that are contained in the exhaust gas flowing into the catalyst are reduced so that the NOx-adsorbing activity cannot be deteriorated by the adhesion activity of the hydrocarbons while maintaining the CO concentration in the exhaust gas flowing into the catalyst at a level higher than the concentration required for the adsorption of NOx.

Abstract: In an engine 5 including an in-cylinder injector, the valve timing of an intake valve is retarded by VVT (Variable Valve Timing) controlled by an engine ECU to decompress in a combustion chamber at engine startup. In accordance with a configuration in which the valve timing of intake valve is advanced in a stepped manner from an initial set value, fuel injection from in-cylinder injector is inhibited during the time when the advance is equal to or below a predetermined standard value, and fuel injection from in-cylinder injector is allowed when exceeding the predetermined standard value, whereby degradation in the exhaust emission level in accordance with start time decompression control can be suppressed.

Abstract: A control apparatus for an internal combustion engine that can prevent, for instance, an exhaust purification catalyst from being damaged when the employed fuel is changed to a fuel having different properties during an operation. If fuel learning is incomplete while a refueling record exists, the throttle opening of an internal combustion engine operable on a fuel that is obtained by mixing alcohol and gasoline at an arbitrary ratio is limited. Limiting the throttle opening makes it possible to avoid an entry into an operation region where fuel increase is performed. This prevents air-fuel ratio feedback control from being stopped when a fuel change occurs. Consequently, the use of an improper air-fuel ratio that may damage the catalyst can be definitely avoided.

Abstract: When an injection sharing ratio r is neither 0 nor 1, an engine ECU executes a program including a step of calculating a purge reduction amount of an in-cylinder injector as fpg×r and calculating a purge reduction amount of an intake manifold injector as fpg×(1?r) when performing purge processing according to a current fuel injection sharing ratio of the injectors, and a step of calculating a correction fuel injection amount of the in-cylinder injector by raising the fuel injection amount to a minimum fuel injection amount, and calculating a correction fuel injection amount of the intake manifold injector by subtracting the raised amount from the fuel injection amount of the intake manifold injector when the fuel injection amount of the in-cylinder injector calculated by using the purge reduction amount is lower than the minimum injection amount.

Abstract: Avoiding inconvenience during purge processing execution of fuel vapor in an internal combustion engine including an in-cylinder injector and an intake manifold injector. An engine ECU 300 executes a program including the steps of: when the purge control execution flag is ON (YES at S400), the step (S410) of calculating injection ratio (DI ratio) r; the step (420) of calculating the basic injection amounts of the in-cylinder injector and the intake manifold injector; when the injection ratio r is not 0 (NO at S430) and the injection ratio r is not 1 (NO at S460), the step (S480) of substituting 0 for purge reduction calculation value fpgd at the in-cylinder injector side, and substituting fpg for purge reduction calculation value fpgp of the intake manifold injector side; and the step (490) of calculating the final injection amounts of the in-cylinder injector and the intake manifold injector.

Abstract: When an injection sharing ratio r is neither 0 nor 1, an engine ECU executes a program including a step of calculating a purge reduction amount of an in-cylinder injector as fpg×r and calculating a purge reduction amount of an intake manifold injector as fpg×(1-r) when performing purge processing according to a current fuel injection sharing ratio of the injectors, and a step of calculating a correction fuel injection amount of the in-cylinder injector by raising the fuel injection amount to a minimum fuel injection amount, and calculating a correction fuel injection amount of the intake manifold injector by subtracting the raised amount from the fuel injection amount of the intake manifold injector when the fuel injection amount of the in-cylinder injector calculated by using the purge reduction amount is lower than the minimum injection amount.

Abstract: An intake-negative-pressure-increasing apparatus is disclosed, for use with an engine, and comprises a bypass passage extending from an intake pipe portion in the neighborhood of the throttle valve to an intake pipe portion downstream of the intake pipe portion in the neighborhood of the throttle valve. A negative pressure is generated by the air flowing through the bypass passage and is supplied to an actuator operated by the negative pressure as the driving power.

Abstract: In a hybrid vehicle driven by a dual injection internal combustion engine including an injector for in-cylinder injection and an injector for in-intake air path injection, and assistive dynamic, to control learning of the internal combustion engine's air fuel ratio learning value to learn the engine's air fuel ratio the engine is steadily operated and only any one of the injectors is allowed to inject fuel, while learning of the air fuel ratio is controlled, and after controlling the learning has completed the other injector is alone allowed to inject the fuel, while learning of air fuel ratio is controlled.

Abstract: In an engine 5 including an in-cylinder injector, the valve timing of an intake valve is retarded by VVT (Variable Valve Timing) controlled by an engine ECU to decompress in a combustion chamber at engine startup. In accordance with a configuration in which the valve timing of intake valve is advanced in a stepped manner from an initial set value, fuel injection from in-cylinder injector is inhibited during the time when the advance is equal to or below a predetermined standard value, and fuel injection from in-cylinder injector is allowed when exceeding the predetermined standard value, whereby degradation in the exhaust emission level in accordance with start time decompression control can be suppressed.

Abstract: An intake-negative-pressure-increasing apparatus is disclosed, for use with an engine, and comprises a bypass passage extending from an intake pipe portion in the neighborhood of the throttle valve to an intake pipe portion downstream of the intake pipe portion in the neighborhood of the throttle valve. A negative pressure is generated by the air flowing through the bypass passage and is supplied to an actuator operated by the negative pressure as the driving power.

Abstract: When an injection sharing ratio r is neither 0 nor 1, an engine ECU executes a program including a step of calculating a purge reduction amount of an in-cylinder injector as fpg×r and calculating a purge reduction amount of an intake manifold injector as fpg×(1-r) when performing purge processing according to a current fuel injection sharing ratio of the injectors, and a step of calculating a correction fuel injection amount of the in-cylinder injector by raising the fuel injection amount to a minimum fuel injection amount, and calculating a correction fuel injection amount of the intake manifold injector by subtracting the raised amount from the fuel injection amount of the intake manifold injector when the fuel injection amount of the in-cylinder injector calculated by using the purge reduction amount is lower than the minimum injection amount.

Abstract: In a hybrid vehicle driven by a dual injection internal combustion engine including an injector for in-cylinder injection and an injector for in-intake air path injection, and assistive dynamic, to control learning of the internal combustion engine's air fuel ratio learning value to learn the engine's air fuel ratio the engine is steadily operated and only any one of the injectors is allowed to inject fuel, while learning of the air fuel ratio is controlled, and after controlling the learning has completed the other injector is alone allowed to inject the fuel, while learning of air fuel ratio is controlled.

Abstract: An in-cylinder injection type spark-ignition internal combustion engine and a control method thereof realize a stabilized stratified-charge combustion by setting a large lift amount to an intake valve when the engine is cold-started and by executing a compression stroke injection. At this time, warming-up capability of a catalyst is improved by delaying an ignition timing.

Abstract: An in-cylinder injection type spark-ignition internal combustion engine and a control method thereof realize a stabilized stratified-charge combustion by setting a large lift amount to an intake valve when the engine is cold-started and by executing a compression stroke injection. At this time, warming-up capability of a catalyst is improved by delaying an ignition timing.

Abstract: In a double air-fuel ratio sensor system having three-way catalysts, a full O.sub.2 storage amount of the three-way catalysts is estimated and compared with a predetermined amount. When the estimated full O.sub.2 storage amount is smaller than the predetermined amount, the three-way catalysts are determined to have deteriorated.

Abstract: A PCV system with a check valve device oriented in a vertical direction and including a valve body, a seat member, and a stopper plate. The valve body includes a valve head constructed of elastomer. The seat member includes a valve seat surface on a lower surface thereof. The seat member further includes at least one perforation which opens into the lower surface. The valve head of the valve body is disposed below the valve seat surface so as to resiliently contact the valve seat surface when no differential pressure acts on the valve. A stopper plate is disposed between the lower surface of the seat member and the valve head of the valve body. The stopper plate prevents the valve head from being excessively deformed into the perforation to cause cracks to develop in the valve head. As a result, the durability of the check valve device is improved.

Abstract: An idling speed control device normally controlling the idling speed of the engine so that it becomes equal to a desired idling speed. At the time of acceleration, the lean time and the rich time of the air-fuel mixture are calculated during the lean-rich discriminating time, which is basically equal to a time of an occurrence of the lean time and the rich time when the air-fuel ratio is maintained at the stoichiometric air-fuel ratio at the time of acceleration. If the lean time becomes considerably longer than the rich time when the engine is started, the idling speed is increased.

Abstract: In a hybrid vehicle driven by a dual injection internal combustion engine including an injector for in-cylinder injection and an injector for in-intake air path injection, and assistive dynamic, to control learning of the internal combustion engine's air fuel ratio learning value to learn the engine's air fuel ratio the engine is steadily operated and only any one of the injectors is allowed to inject fuel, while learning of the air fuel ratio is controlled, and after controlling the learning has completed the other injector is alone allowed to inject the fuel, while learning of air fuel ratio is controlled.