Stratified burning internal combustion engine

摘要

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