Intake apparatus for internal combustion engine

An intake apparatus for an internal combustion engine, the apparatus comprising:

• an intake manifold including a plurality of air feeding passages that define feed switch openings and a bore portion and that are adapted to be connected to and feed air to a plurality of cylinders of an internal combustion engine when the air feeding passages are connected to the internal combustion engine;
• a rotary valve defining an axial direction and including a plurality of valve portions that are rotatable together and each of which is in communication with corresponding one of the air feeding passages through corresponding one of the feed switch openings, the rotary valve located in the bore portion and being supported to the intake manifold to be rotatably switched between an open position wherein the plurality of valve portions open the feed switch openings and a closed position wherein the plurality of valve portions close the feed switch openings;
• a sealing member fitted to each of the valve portions, the sealing member including a pair of ring portions, each of which engages corresponding one of opposite ends of the valve portion in the axial direction and at least two interconnecting portions interconnecting the pair of ring portions, each of the sealing members providing sealing between associated one of valve portions and the bore portion of the intake manifold, the interconnecting portions being generally located along the feed switch opening and radially between the valve portion and the bore portion when the rotary valve is switched to the closed position;
• each valve portion including a wall plate member and a recessed portion on an outer side of the wall plate member, each recessed portion having a first inner face portion and a second inner face portion facing each other and positioned on opposite sides of the recessed portion;
• each interconnecting portion including an engaging portion on an inner side of the interconnecting portion;
• wherein when the rotary valve is switched to the closed position, a first sealing gap between one of the engaging portions and the first inner face portion of one of the recessed portions located on a side opposite, with respect to the engaging portion, from the other side where the feed switch opening is located, is set smaller than a valve gap provided between the valve portion and the bore portion;
• and
• wherein when the rotary valve is switched to the closed position, a second sealing gap between one of the engaging portions and the second inner face portion of one of the recessed portions located closer to the feed switch opening than the engaging portion is greater than the first sealing gap, and wherein a sum of the first sealing gap and the second sealing gap is greater than the valve gap.