ENGINE WHOSE EXPANSION STROKE OF FUEL-AIR MIXTURE OR AIR IS LONGER THAN COMPRESSION STROKE THEREOF WHEN PISTON VALVE OR ROTARY VALVE IS USED FOR 4-CYCLE ENGINE OR 6-CYCLE ENGINE

摘要

PROBLEM TO BE SOLVED: To provide an engine having the characteristic of being compression ratio smaller than expansion ratio when a piston valve or a rotary valve is used for a 4-cycle engine or a 6-cycle engine. ;SOLUTION: When a piston valve is used for a 4-cycle gasoline engine, an engine having a characteristic of compression ratio expansion ratio, or that an expansion stroke is longer than a compression stroke, can be obtained by providing a valve 3 which opens a bottom dead center in a compression stroke and closes a little before a top dead center aside from an intake valve 1 and an exhaust valve 2. For measures against the case where the valve 3 is excessively opened, the expansion ratio can be further increased in comparison with the compression ratio by providing an air intake valve 4 which opens before fuel-air mixture or air excessively expands to be resistant to rotation in the expansion stroke and closes at the bottom dead center. In the case of a diesel engine, the same effect can be obtained by opening an exhaust valve at the bottom dead center of the compression stroke and closing it a little before the top dead center.;COPYRIGHT: (C)1997,JPO