Abstract: A control apparatus of an internal combustion engine in which a plurality of cylinders is divided into a first cylinder group (1a) and a second cylinder group (1b), the internal combustion engine being able to be selectively switched between operating in a partial cylinder operation mode in which only one of the first cylinder group (1a) and the second cylinder group (1b) is operated, and operating in a full cylinder operation mode in which both the first cylinder group (1a) and the second cylinder group (1b) are operated. This control apparatus includes a supercharger (8), as well as a controller (30) that selectively starts and stops operation of the supercharger (8) depending on a load on the internal combustion engine when the internal combustion engine is to be operated in the partial cylinder operation mode.

Abstract: A fuel injection apparatus and a fuel injection control method for an internal combustion engine which performs a direct injection operation for injecting fuel from an injector for cylinder injection into a cylinder and a port injection operation for injecting fuel from an injector for intake port injection into an intake port. When a request to change from fuel injection from the injector for cylinder injection to fuel injection from the injector for intake port injection is made, the fuel injection mode of a particular cylinder is changed at a point of time according to the changing request for the particular cylinder. Accordingly, transition to the optimum fuel injection mode is performed in a short time, and a required amount of air-fuel mixture can be obtained. It is therefore possible to suppress fluctuation of torque and deterioration of emission.

Abstract: A boost pressure control apparatus includes a turbocharger whose turbine is rotationally driven by exhaust of an internal combustion engine, and an EGR device, wherein EGR is performed at the time of supercharge, or the EGR amount is increased at the time of supercharge in comparison with when supercharge is not performed. If the internal EGR gas amount is increased by changing opening/closure timings of intake valves and/or exhaust valves via the EGR device, the energy of exhaust can be increased, so that the rotation speed of the turbocharger can be enhanced. Therefore, the responsiveness of boost pressure rise can be enhanced. Thus, a technology of more promptly raising the boost pressure is provided.

Abstract: An engine includes an in-cylinder injector injecting fuel into a cylinder, a port injector injecting fuel into an intake manifold, and a valve-opening-characteristic changing mechanism changing at least lift or opening duration of an intake valve. When the engine is in a predetermined operating region and the valve-opening-characteristic changing mechanism decreases the lift or the opening duration of the intake valve, the ratio of fuel injected by the in-cylinder injector is increased according to an amount of the decrease of the lift or the opening duration and accordingly a decrease in tumble ratio is compensated for by the injection flow.

Abstract: An engine includes an in-cylinder injector injecting fuel into a cylinder, a port injector injecting fuel into an intake manifold, and a valve-opening-characteristic changing mechanism changing at least lift or opening duration of an intake valve. When the engine is in a predetermined operating region and the valve-opening-characteristic changing mechanism decreases the lift or the opening duration of the intake valve, the ratio of fuel injected by the in-cylinder injector is increased according to an amount of the decrease of the lift or the opening duration and accordingly a decrease in tumble ratio is compensated for by the injection flow.

Abstract: A control system for a supercharged internal combustion engine provided with a main exhaust passage (20) extending through a turbocharger turbine (21) and further through a catalyst (23, 24) to open to the outside air, an exhaust bypass passage (25) by passing the turbocharger turbine by branching from the main exhaust passage at the upstream side of the turbine and merging with the main exhaust passage before reaching the catalyst at the turbine downstream side, and an exhaust bypass valve (26) provided at the exhaust bypass passage, the control system for a supercharged internal combustion engine controlling the ignition timing in accordance with at least one of the engine warmup state and the catalyst warmup state until warmup of the internal combustion engine and warmup of the catalyst are completed and further controlling the opening degree of the exhaust bypass valve based on the control of the ignition timing, is provided.

Abstract: A fuel injection apparatus and a fuel injection control method for an internal combustion engine which performs a direct injection operation for injecting fuel from an injector for cylinder injection into a cylinder and a port injection operation for injecting fuel from an injector for intake port injection into an intake port. When a request to change from fuel injection from the injector for cylinder injection to fuel injection from the injector for intake port injection is made, the fuel injection mode of a particular cylinder is changed at a point of time according to the changing request for the particular cylinder. Accordingly, transition to the optimum fuel injection mode is performed in a short time, and a required amount of air-fuel mixture can be obtained. It is therefore possible to suppress fluctuation of torque and deterioration of emission.

Abstract: An internal combustion engine is operated with a predetermined fixed A/F ratio in an operating range where the amount of intake air is not larger than a predetermined value but, in an operating range where the amount of intake air is larger than the predetermined value, the internal engine is operated with a variable lean A/F ratio which increases from the fixed A/F ratio as the amount of intake air increases. To achieve this, in a throttle valve (7a) whose opening is controlled based on a signal from an accelerator pedal position sensor (17), control is performed so that the correspondence ratio between the accelerator pedal position and the throttle valve opening increases as the A/F ratio increases. In the operating range where the engine is operated with a variable lean A/F ratio, the amount of intake air is increased by using a turbocharger (2).

Abstract: An engine includes an in-cylinder injector injecting fuel into a cylinder, a port injector injecting fuel into an intake manifold, and a valve-opening-characteristic changing mechanism changing at least lift or opening duration of an intake valve. When the engine is in a predetermined operating region and the valve-opening-characteristic changing mechanism decreases the lift or the opening duration of the intake valve, the ratio of fuel injected by the in-cylinder injector is increased according to an amount of the decrease of the lift or the opening duration and accordingly a decrease in tumble ratio is compensated for by the injection flow.

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: A NOx occluding member that occludes NOx when the air-fuel ratio is on the fuel-lean side is disposed in an engine exhaust passage. An NOx ammonia sensor is disposed in the engine exhaust passage downstream of the NOx occluding member. A surplus amount of a reducing agent that is not used to release NOx is determined from a change in the ammonia concentration detected by the NOx ammonia sensor when the air-fuel ratio is changed to the fuel-rich side so as to release the NOx from the NOx occluding member.

Abstract: The exhaust emission control apparatus is provided with a NOx catalyst for purifying exhaust gas flowing out of an internal combustion engine, and a NOx sensor for detecting a NOx concentration in exhaust gas flowing out of the NOx catalyst. The internal combustion engine and the exhaust emission control apparatus are mounted on a vehicle. The exhaust emission control apparatus calculates a total outflow amount of NOx flowing out of the NOx catalyst obtained while the vehicle runs for a predetermined distance based on a NOx concentration detected by the above-mentioned NOx sensor, calculates a NOx outflow amount per unit running distance based on the total NOx outflow amount, and supplies the NOx catalyst with exhaust gas with a rich air-fuel ratio when a NOx outflow amount per unit running distance exceeds a predetermined amount.

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: The exhaust emission control apparatus is provided with a NOx catalyst for purifying exhaust gas flowing out of an internal combustion engine, and a NOx sensor for detecting a NOx concentration in exhaust gas flowing out of the NOx catalyst. The internal combustion engine and the exhaust emission control apparatus are mounted on a vehicle. The exhaust emission control apparatus calculates a total outflow amount of NOx flowing out of the NOx catalyst obtained while the vehicle runs for a predetermined distance based on a NOx concentration detected by the above-mentioned NOx sensor, calculates a NOx outflow amount per unit running distance based on the total NOx outflow amount, and supplies the NOx catalyst with exhaust gas with a rich air-fuel ratio when a NOx outflow amount per unit running distance exceeds a predetermined amount.

Abstract: A NOx occluding member that occludes NOx when the air-fuel ratio is on the fuel-lean side is disposed in an engine exhaust passage. An NOx ammonia sensor is disposed in the engine exhaust passage downstream of the NOx occluding member. A surplus amount of a reducing agent that is not used to release NOx is determined from a change in the ammonia concentration detected by the NOx ammonia sensor when the air-fuel ratio is changed to the fuel-rich side so as to release the NOx from the NOx occluding member.

Abstract: An internal combustion engine having an intake passage that is closed at the time of engine starting operation wherein a holding time for completely closing a throttle valve is made as long as possible within such a range that the engine does not fail to be started. The throttle valve is held at its full-closure position when an ignition switch is turned on. Then, at the time of engine starting operation, an amount of air consumed by the engine is calculated based on a cumulative rotational speed of the engine, a cylinder volume of the engine, and a parameter of volumetric efficiency corresponding to an engine rotational speed, and, if so, the throttle valve is opened to a predetermined opening degree.

Abstract: An engine control apparatus is disclosed, in which the combustion instability is improved regardless of the type of fuel supplied to the engine so that the idle state immediately after an engine start is stabilized for improving the fuel consumption rate, preventing the deterioration of emission and thereby improving the durability of catalysts. A counter counts the time elapsed from an engine start. A sensor detects the engine speed. A control circuit controls the timing of fuel injection into the engine. The intake-synchronous injection is carried out during a first predetermined time immediately after a cold engine start. The intake-asynchronous injection is carried out after the lapse of the first predetermined time. During the intake-asynchronous injection, the engine speed is monitored to determine whether it is reduced below a reference engine speed until the lapse of a second predetermined time.