| 摘要 |
<P>PROBLEM TO BE SOLVED: To restrain the clogging of a fuel adding valve for adding fuel to an exhaust passage even if the exhaust temperature of an internal combustion engine changes by an environmental change such as an atmospheric pressure change. <P>SOLUTION: A correction is made so as to shorten an adding interval of the fuel (Step ST1 to ST4) as a variation in its exhaust temperature becomes large on the basis of a variation in the present exhaust temperature to the basis exhaust temperature when setting a basic adding interval. When the exhaust temperature rises in highland by such a correction of the adding interval, the adding interval of the fuel is shortened and corrected in response to its exhaust temperature rise, and since an adding quantity of the fuel is increasingly corrected, a temperature rise in a tip part of the fuel adding valve can be restrained, to thereby avoid the problem of blocking up a nozzle port of the fuel adding valve by a deposit. <P>COPYRIGHT: (C)2007,JPO&INPIT |
