Stratified burning international combustion engine.

摘要

An internal combustion engine according to this invention is provided with intake ports (46A,46B) and an injector. The intake ports are designed to form stratified tumble flows of different fuel concentrations in a combustion chamber. A spark plug (11) is arranged in the combustion chamber to ignite one of the tumble flows, which one tumble flow (Fm) is rich in fuel. Each intake port is provided with a longitudinal partition (21) which divides an interior of the intake port into two passages (4,5). These longitudinal partitions (21) are formed in such a way that, of the air-fuel tumble flows formed around the spark plug, the tumble flow closest to the spark plug is formed of a richer air-fuel mixture. Each longitudinal partition (21) is arranged only on a side upstream of a valve stem (57) of an intake valve (58) in the corresponding intake port (46A or 46B), so that a sufficient amount of intake air can be obtained while extremely minimizing a reduction in the actual cross-sectional flow area.