engine

The injection port is positioned asymmetrically on the lower side of the communication passage relative to its central axis, creating an asymmetric flow pattern that directs gas fuel toward the intake port while preventing accumulation in the surge tank area. This asymmetric configuration resolves the contradiction by optimizing both supply efficiency and residual fuel prevention simultaneously.

The injection port is oriented to inject gas fuel in a direction that utilizes the vertical dimension of the communication passage. By injecting from the lower side upward and outward, the gas fuel is directed along a three-dimensional path that promotes complete discharge through the intake port while preventing pooling in the surge tank, thus resolving the contradiction between supply efficiency and abnormal combustion prevention.

The injection port is positioned asymmetrically on the lower side of the communication passage rather than at the center or upper side. This asymmetric positioning creates a flow pattern that naturally directs gas fuel toward the intake port discharge path, preventing residual fuel accumulation. The asymmetric design simultaneously maintains easy injection operation and eliminates harmful residual gas fuel.

The design converts the potential harm of gas fuel remaining in the passage into a benefit by using the injection port's lower-side positioning to create a flow pattern where any residual fuel is naturally directed toward the intake port discharge. The configuration turns what could be a harmful accumulation into a controlled flow that promotes complete discharge, resolving the contradiction between operational ease and harmful factor elimination.