| 摘要 |
<P>PROBLEM TO BE SOLVED: To temporarily adsorb the fuel injected just after engine start and reduce an HC emission by coating a piston crown surface with HC trap. <P>SOLUTION: The crown surface of a piston 18 fittingly inserted for reciprocating motion in a cylinder 10A is coated with the HC trap 54 temporarily adsorbing HC which is a principle component of the fuel. A porous member such as zeolite may be used as the HC trap 54, for instance. With this, the fuel attached to a cylinder wall surface just after engine start is scraped together by a top ring 12, moves to the crown surface and is temporarily adsorbed by the HC trap 54 when the piston 18 moves from a bottom dead center to a top dead center. When engine warming-up progresses and temperature of the piston 18 rises, the fuel adsorbed by the HC trap 54 gradually separates, is burnt with a mixture and is disposed. A trap catalyst 44 may be arranged on an exhaust duct 44 defining an exhaust passage, considering possibility that the HC adsorbing amount of the HC trap 54 will be saturated. <P>COPYRIGHT: (C)2009,JPO&INPIT |
