| 摘要 |
PURPOSE:To easily generate each laminar flow for rich mixture and lean mixture so as to accurately insure lean combustion by providing a guide plate on the lower stream side of a valve stem, and injecting fuel toward the guide plate. CONSTITUTION:In this engine EG of lean combustion system, at least two intake ports are provided against one cylinder 1 with a spark plug 5 fitted to the upper part. Each intake port 3 is provided with an intake valve 5 having a valve stem 5a capably of being opened/closed, and a fuel injection valve 6 is provided on the upper stream part of the valve stem 5a. In this case, a guide plate 7 smoothly guiding inflowing intake air in the direction of the intake port 3 is projectingly provided on the lower stream side of the valve stem 5a, concentrated in one direction between the guide plates 7 so that relative rich intake air flow is guided into the vicinity of the spark plug, so as to make efficient lean combustion possible. |
