| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress conditions in which a calculated learned value becomes improper as a value corresponding to a stationary displacement between a catalyst floor temperature and a target floor temperature, and the supplied amount of the unburned fuel components for the learned value is excessively is excessively corrected. <P>SOLUTION: When the target floor temperature Tt of a catalyst is increased more than before during the temperature raising control, the averaged value of the added amount of fuel from an addition valve 46 per unit time is increased so that the averaged value Tave of catalyst floor temperatures can follow up the target floor temperature Tt. However, a temperature differenceΔT between the averaged value Tave of the catalyst floor temperatures and the target floor temperature Tt is temporarily increased based on the heat capacity of the catalyst. If a learned value K is calculated based on a ratio Tt/Tave, the calculated learned value K becomes improper as a value corresponding to the stationary displacement between the averaged value Tave of the catalyst floor temperature and the target floor temperature Tt. However, the learning of the learned value K is prohibited in a period between the time when the target floor temperature Tt is increased more than before and the time when the catalyst floor temperature T is stabilized. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
