Abstract: A control unit for an internal combustion engine includes a load detector to detect a load on the engine, an injection volume calculator to calculate a cylinder injection volume indicating a volume of fuel injected from a direct injector, a first controller to perform a first control for increasing the frequency of the injection by the direct injector upon a reduction in the cylinder injection volume, a second controller to perform a second control for increasing a port injection volume indicating a volume of fuel injected from a port injector upon a reduction in the cylinder injection volume, and a switching controller to switch between the first control with the first controller and the second control with the second controller depending on the load.

Abstract: A control unit for an internal combustion engine includes a load detector to detect a load on the engine, an injection volume calculator to calculate a cylinder injection volume indicating a volume of fuel injected from a direct injector, a first controller to perform a first control for increasing the frequency of the injection by the direct injector upon a reduction in the cylinder injection volume, a second controller to perform a second control for increasing a port injection volume indicating a volume of fuel injected from a port injector upon a reduction in the cylinder injection volume, and a switching controller to switch between the first control with the first controller and the second control with the second controller depending on the load.

Abstract: There is provided a combustion chamber structure in an internal combustion engine in which, at a peripheral portion of a combustion chamber, a gap between a cylinder head lower face and a piston upper face is small in intake-to-intake and exhaust-to-exhaust zones and gradually increases toward an intake-to-exhaust zone. According to such design, the mixture in the peripheral portion of the combustion chamber can smoothly flow from the intake-to-intake and exhaust-to-exhaust zones to the intake-to-exhaust zone along the peripheral face of the cylinder. The flow of air-fuel mixture from the intake-to-intake zone collides at the center of the intake-to-exhaust zone with the flow of mixture from the exhaust-to-exhaust zone, and the combined flow goes over a conical tapered portion in the upper face of the piston and vigorously enters a central recessed portion thereof. Therefore, it is possible to satisfactorily mix an air-fuel mixture with a simplified configuration.

Abstract: There is provided a combustion chamber structure in an internal combustion engine in which, at a peripheral portion of a combustion chamber, a gap between a cylinder head lower face and a piston upper face is small in intake-to-intake and exhaust-to-exhaust zones and gradually increases toward an intake-to-exhaust zone. According to such design, the mixture in the peripheral portion of the combustion chamber can smoothly flow from the intake-to-intake and exhaust-to-exhaust zones to the intake-to-exhaust zone along the peripheral face of the cylinder. The flow of air-fuel mixture from the intake-to-intake zone collides at the center of the intake-to-exhaust zone with the flow of mixture from the exhaust-to-exhaust zone, and the combined flow goes over a conical tapered portion in the upper face of the piston and vigorously enters a central recessed portion thereof. Therefore, it is possible to satisfactorily mix an air-fuel mixture with a simplified configuration.

Abstract: The present invention relates to an automotive vehicle engine having controls for switching between a whole cylinder working mode and a partial cylinder non-working mode by making a valve motion arrangement operated in the intake and exhaust process. The automotive vehicle engine comprises-a revolution sensor, a boost pressure sensor, an ignition driving apparatus and a controlling apparatus for controlling the cylinder suspending mechanism and the ignition driving apparatus. The partial cylinder non-working mode or the all cylinder working mode is determined on the basis of the revolution speed "Ne" and the boost pressure data "Pb".