| abstract |
An object of the present invention is to quickly activate a catalyst while suppressing harmful exhaust gas emissions as much as possible. When the engine water temperature Tw (or exhaust temperature) does not reach a preset temperature Tc indicating activation of a catalyst, and the battery voltage VB is equal to or higher than the preset voltage value Vc, If it is determined that the charging capacity is sufficient, the engine is operated under no load with the clutch released. As a result, the catalyst is activated early by operating the engine. Further, since the operation of the engine is performed in a no-load state, harmful components in exhaust gas discharged through a catalyst that is not sufficiently activated can be reduced. [Selection diagram] FIG. |