Abstract: A direct-fuel-injection-type spark-ignition internal combustion engine is disclosed. The engine comprises a spark plug, a cavity formed on the top surface of the piston, and a fuel injection valve for injecting fuel into the cavity in nearly the shape of a fan having a relative small thickness. In the engine, the side wall of the cavity facing the fuel injection valve, for leading the fuel to the vicinity of the spark plug, has a horizontal sectional shape consisting of a part of an ellipse shape of which two foci are at a position of the injection hole of the fuel injection valve and a position near to the spark plug in plan view, and the side wall has a deflecting portion to deflect the fuel toward the inside of the cavity.

Abstract: In a direct fuel injection-type spark ignition internal combustion engine including a spark plug and a fuel injector for injecting fuel directly into the cylinder, the engine can carry out stratified charge combustion by the fuel injection in the compression stroke and uniform charge combustion by the fuel injection in the intake stroke. The engine includes a mechanism which can make a tumbling stream formed in the cylinder in the intake stroke in the stratified charge combustion weaker than that in the uniform charge combustion.

Abstract: The warming up control device according to the present invention determines precisely whether the temperature of the catalytic converter of the internal combustion engine has reached the activating temperature of the catalyst after the engine starts, The device estimates the heat amount transferred from the exhaust gas the catalytic converter based on the amount of the fuel supplied to the engine, and calculates the total heat amount transferred to the catalytic converter after the engine starts. The device determines that the temperature of the catalytic converter reaches the activating temperature of the catalyst when the calculated total heat amount reaches a predetermined value. Since the completion of the warming up of the catalytic converter is precisely determined, the warming up operation of the catalyst, such as the ignition timing retardation, can be terminated at a proper time, thus an unnecessary increase in fuel consumption and a deterioration in the engine performance can be avoided.

Abstract: A turbine, which is an essential portion of an air motor, is disposed midway along an air-intake passage communicating to combustion chambers of an engine. A generator is operably connected to an output shaft of the turbine. The generator has a function to control the rotational motion of the turbine in proportion to the magnitude of the generated electric energy, in addition to the original function of generating the electric energy. The generator is electrically connected to an air-intake control device. In other words, the air-intake control device includes a transistor, and potentiometer which includes a resistor and a sliding element. A positive electrode of generator is connected to an emitter of the transistor. Further, a base of the transistor is connected to an output terminal of the potentiometer, and a collector thereof to a battery. When the operation magnitude of an acceleration pedal is small, the current flowing through the base decreases.