| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the deterioration of durability caused by current-carrying to an electric heating type catalyst(ETC) at a low temperature by setting the current-carrying power to the electric heating type catalyst at an engine temperature not more than a second set temperature lower than a first set temperature lower than the current-carrying power at an engine temperature than the second set temperature. SOLUTION: A change-over switch 20 having a normally closed contact 20a for connecting an on-vehicle battery 19 is arranged on the output side of an alternator 18 driven by an engine, EHC 14 is connected to the normally open contact 20b and an air pump 17 is connected to the normally closed contact 20a through an opening and closing switch 21. The change-over switch 20 and the opening and closing switch 21 are switched by a controller 5 to carry a current to the EHC 14 and the air pump 17. As the engine temperature or the judgment value related to water temperature TW, a first set temperature requiring the heating of the EHC 14, a second set temperature easily causing the deterioration of durability by the heat shock of the EHC 14 and a third set temperature making the current carrying to the EHC 14 impossible are used.</p> |
