Air-fuel ratio controller for internal-combustion engine

Claim 1

An air-fuel ratio controller for an internal-combustion engine comprising air-fuel mixture supply means for changing the air-fuel ratio of the mixture being fed to the engine in response to an input signal, means for conducting the air-fuel mixture from the supply means to the engine cylinders, catalyst means for removing harmful constituents from the exhaust gases, an exhaust pipe for conducting the exhaust gases from the engine to the catalyst means, a detector installed on the exhaust pipe to detect the conditions of the exhaust gases, said detector having output characteristics such that, centering around a first range of actual air-fuel ratio of the mixture being fed to the engine, there are a first region where the output sharply varies away from either side of the first range and a second region where the variation in output is moderate a certain value away from the first range, means for outputting a first signal inversely proportional to the rate of output variation relative to the first region of air-fuel ratio in the output characteristics of the detector, means for outputting a second signal inversely proportional to the rate of output variation relative to the second regions of air-fuel ratio in the output characteristics of the detector, said first and second signal outputting means both serving as means for compensating the output of the detector, first connector means for connecting the output of the detector with the inputs of the first and second signal outputting means which serve the compensating means, and second connector means for applying the output of the compensating means to the input of the air-fuel mixture supply means.