Intake passage structure for an internal combustion engine

摘要

An intake passage structure for an internal combustion engine has a first passage portion where a throttle valve (2) is disposed and a second passage portion, downstream of the fist passage portion, where a mesh member (3) is disposed. A relationship S1 </= alpha S2 holds between a cross-sectional area S1 of the first passage portion and a cross-sectional area S2 of the second passage portion where a is an open area rate of the mesh member (3). A clearance (c) may be provided between a periphery of the mesh member (3) and an inside surface of the intake pipe (9) where the mesh member (3) is disposed. <IMAGE>