PURPOSE: To enable facilitation of re-adhering of a suction pipe to an engine body after removal thereof even after the pipe is used for a long time, by a method wherein a portion, where the suction port of the suction pipe makes contact with an opening in an engine body, is formed by a material being excellent in resistance to heat, and other part is maded of a material being excellent in resistance to oil.
CONSTITUTION: A suction pipe 24 is provided in the central position of an inner wall thereof with a projection line 26 extending throughout a whole periphery, and the open ends of a suction port 18 and a feed air port 22 are respectively brought into contact with both sides of the projection line 26. A base body 28 of the suction pipe 24 is formed by nitrile rubber, being excellent in resistance to oil, resistance to bending and fatigue, and resistance to vibration, and an inner wall part brought into contact with the opening part of the suction port 18 is formed by a covering layer 30 being excellent in resistance to heat and resistance to oil.
YAGUCHI FUMIYOSHI
TAKANAKA AKIRA
OTSUKA GOMME KAGAKU KK