| 摘要 |
PROBLEM TO BE SOLVED: To provide a control device for an internal combustion engine reducing total emission quantity of hydrocarbon in exhaust gas discharged until target temperature of a warming up state is reached in start of an engine by making a catalyst reach a state not requiring a warming up process in a short period of time. SOLUTION: Ignition timing is subjected to retardation control in a first step catalyst warming up control operation and the catalyst is warmed up by high temperature exhaust gas.Catalyst inlet temperature is estimated based on elapsed time t after engine start and cooling water temperature, and operation is changed over to a second step catalyst warming up control operation (fuel cut rich control) when the temperature reaches prescribed temperature T1. Greater quantity of oxygen than oxygen in exhaust gas after lean combustion is sent to the catalyst in the second step catalyst warming up control operation to induce quick oxidation reaction in the catalyst. When catalyst inlet temperature estimated and operated with reaction heat taken into account reaches prescribed T2 after about 3 seconds, operation is changed over to a third step catalyst warming up control operation (lean rich control). When catalyst outlet temperature reaches the prescribed T2, catalyst warming up control operation is completed. COPYRIGHT: (C)2011,JPO&INPIT
|
