Abstract: The drive control of the invention sets a rotation speed Ni for in-cylinder injection according to an operation curve used in operation of an engine with fuel injection from only in-cylinder fuel injection valves and a rotation speed Np for port injection according to an operation curve used in operation of the engine with fuel injection from only port fuel injection valves (steps S150 and S160). The drive control subsequently sets a target rotation speed Ne* and a target torque Te* of the engine by distributing the rotation speed Ni for in-cylinder injection and the rotation speed Np for port injection by an allocation rate k of in-cylinder fuel injection to port fuel injection (step S170).

Abstract: An engine ECU executes a program including the step of calculating an injection time Astart from the engine speed and load factor when arriving at the injection calculation timing of a cylinder located in the proximity of a knock sensor, the step of calculating an injection period TAU, the step of calculating an injection end time Aend, the step of shortening the injection time of an in-cylinder injector when the injection time Astart or injection end time Aend is within a KCS gate, and the step of calculating the port injection period so as to inject the insufficient injection quantity from an intake manifold injector when the required injection quantity will be insufficient as a result of shortening the injection period of the in-cylinder injector.

Abstract: An engine ECU executes a program including the steps of: determining presence of abnormality in a high-pressure fuel system; when abnormality is sensed in the high-pressure fuel system, and not in an in-cylinder injector, injecting fuel from the in-cylinder injector at the feed pressure; selecting criteria (1) that is the restriction standard for a more gentle output restriction of the engine; when abnormality is sensed in the high-pressure fuel system and in the in-cylinder injector, ceasing the in-cylinder injector; selecting criteria (2) that is the restriction standard for a stricter output restriction of the engine; increasing the VVT overlap; retarding the ignition timing; and restricting the throttle opening according to the selected criteria.

Abstract: An electric variable valve timing mechanism and a starter are actuated by electricity supplied from a common battery. During an engine starting process, the starter is actuated, and an electronic control unit controls the electric variable valve timing mechanism. The electronic control unit limits the actuation of the electric variable valve timing mechanism on the condition that, during the engine starting process, the voltage value of the battery falls below a predetermined threshold value that degrades the operation of the starter. As a result, the engine is started in a stable manner.

Abstract: A high-pressure fuel supply system is suitable for an internal combustion engine having an in-cylinder injector for injecting a fuel into a cylinder. The high-pressure fuel supply system includes a high-pressure fuel pump driven by an engine, a high-pressure delivery pipe supplying the fuel from the high-pressure fuel pump to the in-cylinder injector, and an actuation valve provided with a leakage function provided between the high-pressure fuel pump and the high-pressure delivery pipe. An amount of leakage in the actuation valve provided with the leakage function is set to an amount not smaller than a discharge amount of the high-pressure fuel pump.

Abstract: An engine ECU executes a program including a step of lowering a pressure of fuel supplied to an in-cylinder injector when it is determined that a degree of dilution of an oil with the fuel is large, a step of calculating a fuel injection period TAUd of the in-cylinder injector with a low fuel pressure, a step of calculating a fuel pressure Pr(0) of the in-cylinder injector required according to an engine speed and a load, a step of calculating a fuel injection period TAUd(0) of the in-cylinder injector with Pr(0), and a step of substituting TAUd(0) for TAUd when TAUd is equal to or larger than TAUd(0).

Abstract: An electronic control apparatus adjusts the pressure such that the fuel supply pressure of a high-pressure fuel supply system is reduced when in a low load mode corresponding to a low required injection quantity. When the operating status of the engine is shifted from a low load to a high load, the fuel supply pressure is boosted again. When determination is made that the current fuel supply pressure is lower than the target fuel supply pressure by at least a predetermined pressure C, the injection quantity ratio of the in-cylinder injector is set lower to reduce the required injection quantity of the in-cylinder injector. Accordingly, noise generated from the high-pressure fuel supply system can be minimized. Further, detrimental effects caused by insufficient fuel supply pressure of the high-pressure fuel supply system can be suppressed when the engine operating status is shifted from a low load to a high load.

Abstract: A control apparatus includes a driving device that is capable of operating regardless whether the engine is running or not. A variable valve actuation mechanism is driven by the driving device. During an idling operation of the engine, a control section controls the driving device such that the variable valve actuation mechanism maintains the valve timing at a valve timing advanced relative to a most retarded valve timing. The control section controls the driving device such that the variable valve actuation mechanism changes the valve timing to the most retarded valve timing after a stopping operation of an autonomous operation of the engine is initiated. Therefore, shock due to the initiation of the engine starting operation is reduced without decreasing fuel economy.

Abstract: A high-pressure fuel supply system is suitable for an internal combustion engine having an in-cylinder injector for injecting a fuel into a cylinder. The high-pressure fuel supply system includes a high-pressure fuel pump driven by an engine, a high-pressure delivery pipe supplying the fuel from the high-pressure fuel pump to the in-cylinder injector, and an actuation valve provided with a leakage function provided between the high-pressure fuel pump and the high-pressure delivery pipe. An amount of leakage in the actuation valve provided with the leakage function is set to an amount not smaller than a discharge amount of the high-pressure fuel pump.

Abstract: When a fuel injection period and a knock determination period switch from a state in which they do not overlap to a state in which they do overlap, operational noise from a fuel injector rides on an output signal from a knock sensor during the knock determination period. By preventing execution of knock control that changes the ignition timing based on determination results from after that switch until a predetermined period of time has passed, it is possible to preferably avoid a case in which the ignition timing is improperly changed based on an erroneous determination in the knock determination due to an effect from operational noise from the fuel injector.

Abstract: An engine ECU executes a program including a step of lowering a pressure of fuel supplied to an in-cylinder injector when it is determined that a degree of dilution of an oil with the fuel is large, a step of calculating a fuel injection period TAUd of the in-cylinder injector with a low fuel pressure, a step of calculating a fuel pressure Pr(0) of the in-cylinder injector required according to an engine speed and a load, a step of calculating a fuel injection period TAUd(0) of the in-cylinder injector with Pr(0), and a step of substituting TAUd(0) for TAUd when TAUd is equal to or larger than TAUd(0).

Abstract: An engine ECU executes a program including the step of calculating an injection time Astart from the engine speed and load factor when arriving at the injection calculation timing of a cylinder located in the proximity of a knock sensor, the step of calculating an injection period TAU, the step of calculating an injection end time Aend, the step of shortening the injection time of an in-cylinder injector when the injection time Astart or injection end time Aend is within a KCS gate, and the step of calculating the port injection period so as to inject the insufficient injection quantity from an intake manifold injector when the required injection quantity will be insufficient as a result of shortening the injection period of the in-cylinder injector.

Abstract: An electronic control apparatus adjusts the pressure such that the fuel supply pressure of a high-pressure fuel supply system is reduced when in a low load mode corresponding to a low required injection quantity. When the operating status of the engine is shifted from a low load to a high load, the fuel supply pressure is boosted again. When determination is made that the current fuel supply pressure is lower than the target fuel supply pressure by at least a predetermined pressure C, the injection quantity ratio of the in-cylinder injector is set lower to reduce the required injection quantity of the in-cylinder injector. Accordingly, noise generated from the high-pressure fuel supply system can be minimized. Further, detrimental effects caused by insufficient fuel supply pressure of the high-pressure fuel supply system can be suppressed when the engine operating status is shifted from a low load to a high load.

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 an engine including a passage injector and an in-cylinder injector that allocates and injects fuel, a fuel injection controller prevents the fuel injection amount of each injector from falling below an allowable lower limit value. When the fuel injection amount of one of the passage injector and the in-cylinder injector becomes less than or equal to a value indicating the possibility of the fuel injection amount falling to less than an allowable lower limit value due to correction with the correction value, the fuel injection amount of only the other one of the passage injector and the in-cylinder injector is corrected with the correction value.

Abstract: Under engine operating conditions in which a default setting for a knock determination period overlaps with a fuel injection period during which fuel is injected by a fuel injector, the fuel injection timing and the knock determination period are set in correlation with each other such that the knock determination period is shorter than its default setting so the fuel injection period and the knock determination period no longer overlap. Accordingly, it is possible to avoid a case in which noise produced by operation of the fuel injector rides on an output signal from a knock sensor during the knock determination period, and thus inhibit a decrease in accuracy of the knock determination due to that noise.

Abstract: In an engine including a passage injector and an in-cylinder injector that allocates and injects fuel, a fuel injection controller prevents the fuel injection amount of each injector from falling below an allowable lower limit value. When the fuel injection amount of one of the passage injector and the in-cylinder injector becomes less than or equal to a value indicating the possibility of the fuel injection amount falling to less than an allowable lower limit value due to correction with the correction value, the fuel injection amount of only the other one of the passage injector and the in-cylinder injector is corrected with the correction value.

Abstract: When a fuel injection period and a knock determination period switch from a state in which they do not overlap to a state in which they do overlap, operational noise from a fuel injector rides on an output signal from a knock sensor during the knock determination period. By preventing execution of knock control that changes the ignition timing based on determination results from after that switch until a predetermined period of time has passed, it is possible to preferably avoid a case in which the ignition timing is improperly changed based on an erroneous determination in the knock determination due to an effect from operational noise from the fuel injector.

Abstract: Under engine operating conditions in which a default setting for a knock determination period overlaps with a fuel injection period during which fuel is injected by a fuel injector, the fuel injection timing and the knock determination period are set in correlation with each other such that the knock determination period is shorter than its default setting so the fuel injection period and the knock determination period no longer overlap. Accordingly, it is possible to avoid a case in which noise produced by operation of the fuel injector rides on an output signal from a knock sensor during the knock determination period, and thus inhibit a decrease in accuracy of the knock determination due to that noise.

Abstract: A method and apparatus control an emission of an internal combustion engine. The emission control of the internal combustion engine has a three-way catalyst and a NOx storage-reduction catalyst in an exhaust passage. The emission control reduces NOx stored in the catalyst to recover its NOx storing capability by performing a rich spike control during a lean burn operation. The emission control apparatus has an electronic control unit that limits the execution time of the rich spike control and, after the elapse of the limited execution time, performs a stoichiometric burn operation. The emission control prevents prolongation of the rich spike control and thereby prevents deterioration of HC and CO emissions. By performing the stoichiometric burn operation after the elapse of the limited time of the rich spike control, the emission control apparatus recovers the NOx storing capability while avoiding deterioration of HC and CO emissions.