Intake duct for internal combustion engine

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

• a pipe-shaped shell including:
• a first molded product formed by a plastic molded product and including an opening extending through the first molded product in a thickness direction, and
• a second molded product formed by a fiber molded product produced through compression molding, wherein the second molded product includes an air-permeable fitting projection fitted into the opening, and the second molded product is joined with an outer surface of the first molded product, wherein
• the shell includes a first segment and a second segment joined with the first segment in a circumferential direction,
• the first segment is formed by a fiber molded product produced through compression molding and includes an air-permeable and low-compression portion and a high-compression portion that is compressed to a higher degree than the low-compression portion,
• the second segment includes the first molded product and the second molded product,
• the first molded product includes a bottom wall, two opposing walls that are bent and extended from two side edges of the bottom wall and opposed to each other, and two flanges that are bent and extended from the two opposing walls,
• the two flanges are joined with the first segment,
• the second molded product is joined with outer surfaces of the bottom wall and the two opposing walls of the first molded product,
• the opening is one of a plurality of openings arranged in the bottom wall and in the opposing walls, and
• the fitting projection is one of a plurality of fitting projections arranged on the second molded product and fitted into the corresponding openings.