Patent ID: 7270109

Claim:
An internal combustion engine comprising: a cylinder head forming a combustion space in cooperation with a cylinder in which a piston is reciprocatively fitted, the cylinder head being provided with an intake port having an intake opening that is open to the combustion space and an intake valve for opening and closing the intake opening; wherein the intake port has an intake flow control port portion having a first projecting portion and a second projecting portion that are provided on a wall surface of the intake port and extending along an intake flow; and a passage cross section of the intake flow control port portion includes a low flow velocity region, and a first high flow velocity region and a second high flow velocity region where a maximum flow velocity of intake gas is large as compared with the low flow velocity region, the low flow velocity region being formed in and around a region where a minimum distance between the first projecting portion and the second projecting portion is formed, the first high flow velocity region and the second high flow velocity region being formed on either side of and across the low flow velocity region and the first and second projecting portions; wherein intake gas reaching the intake opening with a flow velocity distribution has a relationship of magnitudes of flow velocities in the low flow velocity region and the first and second high flow velocity regions.