| 摘要 |
PURPOSE:To improve the stability of an engine operation by providing a state discrimination device to find errors in an oxygen concentration detecting device and also by providin a time limiting device to stop feedback correction based on the integral processing in a control device. CONSTITUTION:An oxygen concentration detecting device 4 detects the concentration of an oxygen in the exhaust gas of an internal-combustion engine. A control command circuit 5 inputs the signals from the oxygen concentration detecting device 4, an exhaust gas thermometer 3, and a throttle opening detection switch 9 as well as the engine rotating speed signal; and judges whether the feedback control should be discontinued or not and then outputs the command signal to an air-fuel ratio control circuit 6 and a warning device 10. The air- fuel ratio control circuit 6 makes a feedback correction for the air-fuel ratio of a mixture generated by a carburetor 7. In this way, when there is any error in the output power of the oxygen concentration detecting device, the air-fuel ratio control circuit 6 discontinues the feedback control to prevent variations of the air-fuel ratio; thus the safety in the operation of the engine can be improved. |
