초록 ▼

An engine air-fuel ratio control system in which the engine operating range is divided into a light load, medium load and heavy load regions. In the light load region, a control of the fuel supply is made so as to provide a mixture of leaner than the stoichiometric value. In the medium load region,

An engine air-fuel ratio control system in which the engine operating range is divided into a light load, medium load and heavy load regions. In the light load region, a control of the fuel supply is made so as to provide a mixture of leaner than the stoichiometric value. In the medium load region, a feedback control is made based on the signal from an O2 sensor and, in the heavy load region, a control is made to provide a richer mixture. In the transient between the light load and medium load regions, the air-fuel ratio is changed with a rate which changes in accordance with the rate of change in the engine load.

대표청구항 ▼

An engine air-fuel ratio control system for controlling air-fuel ratio of a mixture to be supplied to the engine, said system including air-fuel ratio control means for providing a first air-fuel ratio in a first region of engine operating condition and a second air-fuel ratio in a second region of

An engine air-fuel ratio control system for controlling air-fuel ratio of a mixture to be supplied to the engine, said system including air-fuel ratio control means for providing a first air-fuel ratio in a first region of engine operating condition and a second air-fuel ratio in a second region of engine operating condition, engine operating condition detecting means for producing an engine operating condition signal which is applied to said air-fuel ratio control means to make the air-fuel ratio control means output a signal corresponding to one of the first and second air-fuel ratios depending on the engine operating condition, engine load change rate detecting means for detecting a rate of change in load on the engine and producing a load change rate signal, air-fuel ratio changing means responsive to said load change rate signal to determine a rate of change in the air-fuel ratio, when the engine operating condition changes between said first and second regions, in accordance with the rate of change in the engine load so that the rate of change in the air-fuel ratio is inreased as the rate of change in the engine load increases.