Patent ID: 6971338
Filing Date: 2005-12-06
Classification: F02B,F02D

Abstract:
1. An engine with variable cycle switchable between a 4-cycle mode and a 2-cycle mode, the engine comprising: a plurality of combustion chambers each including a cylinder, a piston, an intake valve and an exhaust valve provided in the cylinder, a fuel injection unit for injecting fuel into the cylinder, and an ignition unit for ignition of the fuel within the cylinder; and a controller that controls an operation of the intake valve, the exhaust valve, the fuel injection unit, and the ignition unit, the controller: executing a plurality of operation modes in accordance with a combination of one of the 4-cycle mode and the 2-cycle mode with one of a combustion ignition control and a self ignition priority control, the combustion ignition control performing an ignition with the ignition unit at a predetermined timing before top dead center of the piston, and the self ignition priority control performing one of an ignition without the ignition unit and an ignition with the ignition unit at a timing delayed from the predetermined timing under the combustion ignition control; and performing at least one transition cycle upon switching of an operation mode of the engine between a first operation mode and a second operation mode, the first operation mode being performed before the switching, the second operation mode being performed after the switching, and the transition cycle performing an operation of a same cycle type as the second operation mode under the combustion ignition control, wherein: the transition cycle is different from the second operation mode in at least one of an intake valve opening timing, an intake valve closing timing, an exhaust valve opening timing, an exhaust valve closing timing, an injection quantity of the fuel, and an injection timing of the fuel; and the combustion ignition control is executed in one of the combustion chambers where a single cycle of the transition cycle is terminated until each of all the combustion chambers terminates a single cycle of the transition cycle irrespective of the second operation mode under one of the combustion ignition control and self ignition priority control.