Abstract: An electronic control for determining knocking in an internal combustion engine having an intake injector for injecting fuel into an air intake port and an in-cylinder injector for directly injecting fuel into a combustion chamber. Knocking is determined based on an output signal from a knock sensor during a knock determination period. The electronic control unit alters the knock determination period in accordance with the ratio of the amount of fuel injected by the two injectors.

Abstract: An internal combustion engine includes an in-cylinder injection valve and an intake port injection valve. An ECU controls the fuel injection valves in a fuel injection mode that corresponds to an operational state of the engine. When deterioration of the combustion state is detected while the engine operational state is in a predetermined operational region where fuel is injected at least from the in-cylinder injection valve, the ECU switches the fuel injection mode such that the ratio of the amount of fuel injected from the in-cylinder injection valve to the entire amount of fuel supplied to the cylinder is decreased. As a result, the engine combustion state is prevented from deteriorating while suppressing noise generated in the fuel pressurizing and supplying system.

Abstract: An internal combustion engine includes an in-cylinder injection valve and an intake port injection valve. The engine is operated in a combustion mode that is selected from at least stratified lean combustion and homogeneous combustion. An ECU selects the combustion mode according to the operational state of the engine, and controls the fuel injection valves in a fuel injection mode that corresponds to the selected combustion mode. When a misfire is detected while the engine is operated in the stratified lean combustion or the homogeneous combustion, the ECU switches the fuel injection mode such that the ratio of the amount of fuel injected from the intake port injection valve to the entire amount of fuel supplied into the cylinder is increased. As a result, misfires are suppressed while preventing the fuel economy from deteriorating.

Abstract: A fuel supplying apparatus of an internal combustion engine includes a first fuel supply system, a second fuel supply system, and a pulsation propagation suppressing unit. The first fuel supply system pressurizes a fuel by a low-pressure pump, and supplies the fuel pressurized by the low-pressure pump to a first fuel injection mechanism. The second fuel supply system is branched from the first fuel supply system, further pressurizes the fuel, pressurized by the low-pressure pump, by a high-pressure pump that is driven according to an operating state of the internal combustion engine, and supplies the fuel pressurized by the high-pressure pump to a second fuel injection mechanism. The pulsation propagation suppressing unit is provided in at least one of the first fuel supply system and the second fuel supply system, and suppresses propagation of a pulsation generated in the high-pressure pump to the first fuel injection mechanism.

Abstract: When an inner wall of a cylinder head is viewed along an axis of a cylinder, a line that passes through a center of a fuel injection port and a center of a valve opening adjacent to the injection port is defined as a first line, and a line that is perpendicular to the first line is defined as a second line. A notch is formed in a part of the inner wall that defines the injection port. Specifically, when the inner wall is divided into sections by the second line, the notch is located in the section in which the adjacent opening exists. The notch is also displaced from the first line. Therefore, a sufficient thickness of the section corresponding to the valve seats of intake and exhaust valves are easily ensured.

Abstract: A fuel injection control apparatus for an engine includes a controller. The controller controls a main fuel injection valve and an auxiliary fuel injection valve. The controller predicts whether the pressure of the pressurized fuel decreases below a permissible value, which is less than a predetermined value, during a period from a point of time after the pressure of the pressurized fuel becomes greater than or equal to the predetermined value till when fuel injected from the auxiliary fuel injection valve reaches the interior of a cylinder of the engine. When the pressure of the pressurized fuel is greater than or equal to the predetermined value, and it is predicted that the pressure of the pressurized fuel will not decrease below the permissible value during the period, the controller causes the main fuel injection valve to start injecting the pressurized fuel.

Abstract: A fuel injection control apparatus for an engine includes a controller. The controller controls a main fuel injection valve and an auxiliary fuel injection valve. The controller predicts whether the pressure of the pressurized fuel decreases below a permissible value, which is less than a predetermined value, during a period from a point of time after the pressure of the pressurized fuel becomes greater than or equal to the predetermined value till when fuel injected from the auxiliary fuel injection valve reaches the interior of a cylinder of the engine. When the pressure of the pressurized fuel is greater than or equal to the predetermined value, and it is predicted that the pressure of the pressurized fuel will not decrease below the permissible value during the period, the controller causes the main fuel injection valve to start injecting the pressurized fuel.

Abstract: In an internal combustion engine in which a throttle valve is substantially fully opened in most of the operating regions such as an in-cylinder injection type internal combustion engine, a technique is provided capable of effectively processing an evaporative fuel while stabilizing a combustion state of the internal combustion engine even in the case that an amount of evaporative fuel generated in a fuel tank or the like is increased. To achieve this technique, a purge amount of evaporative fuel is increased by increasing a differential pressure between an upstream portion and a downstream portion of a purge passage, and the differential pressure between an upstream portion and a downstream portion of a purge passage, and the differential pressure is adjusted in accordance with the combustion state of the internal combustion engine at that time, thereby making it possible to purge the maximum amount of evaporative fuel within a range in which the combustion state is not unstabilized.