Patent ID: 6513322
Filing Date: 2003-02-04
Classification: F01N,F02D,Y02T

Abstract:
A device for controlling the rise of the catalyst temperature in an internal combustion engine, said device comprising:a catalyst which is a three-way converter provided in an exhaust pipe of the internal combustion engine; a catalyst temperature pick-up means for picking up data corresponding to the temperature of the catalyst as catalyst temperature; a plurality of sensors for detecting operation conditions of said internal combustion engine, wherein said sensors include an air intake sensor and a water temperature sensor; an idling control means for controlling the idling rotational speed of said internal combustion engine depending upon said operation conditions; an idling rotational speed increasing means which, when said catalyst temperature is lower than a predetermined temperature corresponding to an activating temperature of said catalyst, corrects a target idling rotational speed of said internal combustion engine toward the increasing side higher than the idling rotational speed of during the normally controlled operation in order to promote the activation of said catalyst; wherein, when said catalyst temperature is lower than said predetermined temperature, said idling rotational speed increasing means sets said target idling rotational speed to an increased activating rotational speed higher than the idling rotational speed of during said normally controlled operation for a predetermined period of time until said catalyst temperature reaches said activating temperature, and wherein said idling rotational speed increasing means includes, a first comparator means for comparing said catalyst temperature with a first predetermined temperature lower than said activating temperature; and a second comparator means for comparing said catalyst temperature with a second predetermined temperature which is higher than said first predetermined temperature and is corresponding to said activating temperature; and sets said target idling rotational speed to said increased activating rotational speed when said catalyst temperature lies within a range between said first predetermined temperature and said second predetermined temperature.