Abstract: An internal combustion engine includes an in-cylinder injector for injecting fuel into a combustion chamber of the engine and an intake system injector for injecting fuel into an intake system connected to the combustion chamber. In a starting state of the engine, an electronic control unit (ECU) causes the in-cylinder injector to perform only the initial injection to the combustion chamber, and causes the intake system injector to perform fuel injections after the initial injection. As a result, favorable engine startability is ensured, and the emission of unburned components is suppressed in the engine starting state.

Abstract: A control apparatus calculates a exhaust gas air-fuel ratio of a plurality of cylinders, in which the operation angle of an intake valve is set to a predetermined operation angle, e.g., a maximum operation angle, based on a value output from an air-fuel ratio sensor so as to minimize a variation in an fuel injection quantity between the plurality of cylinders by that exhaust gas air-fuel ratio. That is, the exhaust gas air-fuel ratio of the plurality of cylinders, in which the valve opening characteristics of the intake valve and an exhaust valve are set such that the intake air amount to be introduced into the plurality of cylinders is limited by the opening amount of a throttle valve, for example, and not limited by the valve opening characteristics of the intake valve or the exhaust valve is calculated, and the variation in the fuel injection quantity among the plurality of cylinders is then reduced by that exhaust gas air-fuel ratio.

Abstract: An engine ECU executes a program including the step of detecting an engine coolant temperature (THW), the step of selecting a map for a warm state as the map for calculating a fuel injection ratio (or a DI ratio) (r) when the engine coolant temperature (THW) is equal to or higher than a temperature threshold value (THW(TH)), the step of selecting a map for a cold state as the map for calculating the fuel injection ratio (or the DI ratio) (r) when the engine coolant temperature (THW) is lower than the temperature threshold value (THW(TH)), and the step of calculating the fuel injection ratio between the in-cylinder injector and the-intake manifold injector (or the DI ratio) (r) based on the engine speed, load factor, and the selected map.

Abstract: An internal combustion engine includes an in-cylinder injector for injecting fuel into a combustion chamber of the engine and an intake system injector for injecting fuel into an intake system connected to the combustion chamber. In a starting state of the engine, an electronic control unit (ECU) causes the in-cylinder injector to perform only the initial injection to the combustion chamber, and causes the intake system injector to perform fuel injections after the initial injection. As a result, favorable engine startability is ensured, and the emission of unburned components is suppressed in the engine starting state.

Abstract: An injection controller for an internal combustion engine that suppresses the accumulation of deposits on a nozzle hole of a direct injection valve. The injection controller includes the direct injection valve, which injects fuel into a cylinder, and an intake passage injection valve, which injects fuel into an intake passage. An ECU, which is connected to the direct injection and intake passage injection valves, executes a first fuel injection mode for injecting fuel with the direct injection valve and a second fuel injection mode for injecting fuel with the intake passage injection valve. The ECU switches fuel injection modes from the second fuel injection mode to the first fuel injection mode for a predetermined period when fuel is to be injected in the second fuel injection mode.

Abstract: A control apparatus calculates a exhaust gas air-fuel ratio of a plurality of cylinders, in which the operation angle of an intake valve is set to a predetermined operation angle, e.g., a maximum operation angle, based on a value output from an air-fuel ratio sensor so as to minimize a variation in an fuel injection quantity between the plurality of cylinders by that exhaust gas air-fuel ratio. That is, the exhaust gas air-fuel ratio of the plurality of cylinders, in which the valve opening characteristics of the intake valve and an exhaust valve are set such that the intake air amount to be introduced into the plurality of cylinders is limited by the opening amount of a throttle valve, for example, and not limited by the valve opening characteristics of the intake valve or the exhaust valve is calculated, and the variation in the fuel injection quantity among the plurality of cylinders is then reduced by that exhaust gas air-fuel ratio.

Abstract: A fuel injection control device for an engine including an intake air control valve arranged in the intake passage comprises a fuel injector arranged in the downstream of the intake air control valve. In the engine starting operation, the intake air control valve is closed. After the completion of the engine starting operation, the intake air control valve is controlled to make the opening thereof equal to the intermediate opening, and the fuel injection time is calculated based on the negative pressure in the intake passage upstream of the intake air control valve. During a delay period in which the opening of the intake air control valve is smaller than the intermediate opening, the fuel injection time is reduced based on the actual opening of the intake air control valve and on the engine speed, to thereby make the fuel amount to be injected equal to the suitable amount.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: An air flow control device of an engine comprising an air flow control valve arranged in the intake passage and actuated by the vacuum operated diaphragm type drive apparatus. At the cranking of the engine, the air flow control valve is held in the closed state. When the engine speed exceeds a predetermined engine speed, for example, 400 rpm, a valve open signal for the air flow control valve is given to the vacuum operated diaphragm type drive device. After the valve open signal is given, during the valve opening delay period of the air flow control valve, an opening area of the idling speed control valve is increased.

Abstract: An engine, having an intake passage, a throttle valve arranged in the intake passage, and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, comprises an air-flow control valve arranged in the intake passage between the fuel injector and the throttle valve. The air-flow control valve is controlled to close during the engine starting operation, and to open after the engine starting operation completes. The air-flow control valve has a valve element having an axis about which the element is rotatable when the valve is opened or closed. The rotational direction of the valve element is selected so that air flowing through the valve is guided by the valve toward the fuel injector when the air-flow control valve is controlled to an intermediate open position which is between the closed position and the full open position.

Abstract: An air-flow control device, for an engine having an intake passage and a fuel injector arranged in the intake passage for injecting fuel into the intake passage, includes an air-flow control valve, and a driving apparatus for driving the air-flow control valve. The air-flow control valve is arranged in the intake passage upstream of the fuel injector. The apparatus includes a first vacuum chamber into which the atmospheric pressure or a negative pressure produced in the intake passage downstream of the air-flow control valve is selectively introduced via a first vacuum control valve, and a second vacuum chamber into which the atmospheric pressure or a negative pressure produced in the intake passage downstream of the air-flow control valve is selectively introduced via a second vacuum control valve. The apparatus drives the air-flow control valve so that the degree of opening of the air-flow control valve becomes larger as the negative pressure in the first and the second vacuum chamber becomes larger.