INLET PORT OF INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To strengthen swirl and to improve volumetric efficiency by a method wherein the curvature at the bottom wall end of a helical channel at a swirl part communicating to an inlet introducing part is formed of a gradually increasing part and a diminishing part along the channel. CONSTITUTION:An inlet port P of an internal combustion engine E comprises an introducing part 9 communicating with inlet air and a swirl part 20 communicating the introducing part 9 and a cylinder chamber 30 centered on a valve stem A0 of an inlet valve 11. The swirl part 20 is arranged from the surface containing shaft center C0 in the cylinder chamber 30 to the valve stem center A0 of the inlet valve 11. Besides, the curvature at the bottom wall end of a helical channel 13 of the swirl part 20 is provided on the gradually increasing part Ra and the diminishing part Rb along the channel 13. Through these procedures, the inlet air from the introducing part 9 may be introduced into the cylinder chamber 30 stably and smoothly through the helical channel 13 strengthening the swirl and improving the volumetric efficiency.