TWO CYCLE INTERNAL COMBUSTION ENGINE

摘要

PROBLEM TO BE SOLVED: To achieve a throttle-less operation and the like by variable control of a closing period of an intake valve in a two cycle internal combustion engine of a relatively simple structure without the need for a scavenging port or a variable valve exhaust system. SOLUTION: A cylinder scavenging operation is carried out by opening both of an inlet valve for switching an air intake path and an outlet valve for switching an air discharge path during a scavenging period in the vicinity of the piston bottom dead-center (2)→(3). At a time of a part load, the closing time of the inlet valve is retarded to the closing time of the outlet valve or later so as to provide a blowing back period with only the inlet valve opened for restraining the air intake amount by the air blowing back and for ensuring the combustion stability by improving the geometric compression ratio (3)→(4). COPYRIGHT: (C)2009,JPO&INPIT