Patent ID: 6168515
Filing Date: 2001-01-02
Classification: B60H

Abstract:
An outside air intake quantity control apparatus for controlling an outside air intake quantity of outside air introduced into a compartment of a vehicle, the outside air intake quantity control apparatus comprising: exhaust gas concentration calculating means for calculating an ambient exhaust gas concentration from a sensor output signal from an ambient exhaust gas sensor; differentiating means for calculating a derivative of the exhaust gas concentration representing a time rate of change of the exhaust gas concentration; first checking means for checking a previous value of the derivative calculated at a previous time, to determine whether a previous exhaust gas concentration change is in one of a stable state and a changing state in a clean direction toward a cleaner state; second checking means for checking whether a current value of the derivative calculated at a current time is equal to or greater than a predetermine derivative threshold; and controlling means for controlling an outside air inlet opening to reduce the outside air intake quantity to a minimum value when the previous exhaust gas concentration change is in one of the stable state and the changing state in the clean direction and the current value of the derivative is equal to or greater than the predetermine derivative threshold.