Intake port structure for internal combustion engine

摘要

An intake port structure includes a collector passageway disposed in an upstream section and the first and second branching passageways disposed in a downstream section that branch from the collector passageway. The intake port structure further includes an intake air flow impact section formed on a crotch portion between first and second branching passageways against which a portion of an intake air flow from the collector passageway collides such that the portion of the intake air flow is dispersed laterally toward both sides of the intake air flow impact section. The intake air flow impact section is recessed to stem portions of intake valves, and includes first and second impact surfaces. The second impact surface is formed along the stem portions of the intake valves. A fuel spray from a fuel injector is atomized when mixed with the dispersed intake air flow in the first and second branching passageways.