Patent attributes
An inlet duct includes a tubular main body formed by a compression-molded fibrous molded body. The main body includes an alternate layout region in which an air-impermeable high-compression portion and an air-permeable low-compression portion hat is compression-molded at a lower compressibility than a compressibility of the high-compression portion are alternately laid out in an axial direction of the main body. The alternate layout region is configured such that an arbitrary pair of points at an equal distance in the axial direction to a central position in an upstream region and a downstream region of the alternate layout region include only points that are both located in the low-compression portions and points one of which is located in the low-compression portion and the other one of which is located in the high-compression portion.
