To effectively increase a flow speed of intake air at low speed operation time of an engine, and to effectively reduce flow resistance of the intake air at high speed operation time.
This intake device has an intake port 7 having the downstream end opening in a combustion chamber, an intake valve 9 arranged in a throat part 73 of this intake port 7, and a shutter valve 17 for deflecting a flow of the intake air by blocking up a part of a peripheral part of the intake port 7 in a low speed area of an engine. A cross-sectional shape of the intake port 7 positioned on the upstream side of the throat part 63 is formed so as to become relatively smaller than the other in the opening area of an opening part positioned in either one of the upper wall 7a side or the lower wall 7b side more than the vertical center line of the opening part. The opening part having the small opening area is formed in an eccentric shape of positioning the passage center on the outer side more than a gravity center position of the whole opening part of the intake port 7. The shutter valve 17 is arranged on the opening part side having the large opening area, and is constituted so as to open-close this part.
YAMAKAWA MASANAO
YAMADA TAKAYUKI
ISHII KENYA
Next Patent: INTAKE AIR DEVICE OF SPARK IGNITION ENGINE