Patent ID: 7588008

Claim:
An intake system of an internal combustion engine, comprising: an engine head; a resin made intake manifold mounted at the engine head and having a plurality of intake passages, the resin made intake manifold forming a receiving portion on an inner wall of each intake passage at a downstream side thereof; and a control unit disposed at the receiving portion, the control unit including: a resin made cartridge; an opening and closing valve disposed at the cartridge; and a shaft for rotating the opening and closing valve, wherein a clearance is provided between an inner circumferential surface of the receiving portion and an outer circumferential surface of the cartridge to allow deformation of the resin made intake manifold, and the cartridge is provided with a flange held between the engine head and the resin made intake manifold, and wherein the flange is provided with an elastic flange portion and a fixed flange portion and a space is defined between the elastic and fixed flange portions.