| 摘要 |
<p>A viscous heater (9) for heating cooling water for cooling a water cooled engine (E) is provided in a cooling water circuit between the engine and a front heater core (15). Even if a viscous switch (73) is turned on by a viscous ECU (200) to heat a passenger compartment using the viscous heater, a viscous clutch (7) is not immediately turned on when the engine is idling. That is, after a delay control time elapses after increasing an idling rotational speed of the engine to a target rotational speed, the viscous heater is turned on. The target rotational speed which is higher than a normal idling rotational speed is set in such a manner that the higher the cooling water temperature is, the lower the target rotational speed becomes. Thus, even if a large load is applied to the engine by operating the viscous heater when the engine is idling, it can improve fuel economy and prevent an engine stall. <IMAGE></p> |
