PURPOSE: To make it possible to suppress a lapse of time until the starting time point of air/fuel ratio feed back control, by generating a corrective signal which finally converges to zero as a function of a time from the start of an internal combustion engine to the end of its warming up.
CONSTITUTION: A time correction unit 10 generates a corrective signal in compliance with a preset function in an air/fuel ratio sensor signal processing circuit 6. Thus, the signal of an air/fuel sensor 3 inputted in the time correction unit 10 is given a correction corresponding to a lapse of time from the instant when a key switch 9 is made by means of an clock signal generated by a clock generator 8. Then, any signal inputted into a temperature correction unit 12 is subjected to correction due to cooling water temperature immediately before start of an engine 1 in response to a signal from a cooling water temperature sensor 11. And this signal is taken into an air/fuel ratio controller 7 in form of a detection signal for correcting an air/fuel ratio to be used in the air/fuel feed back control. Therefore, even though the heating rate on the air/fuel sensor 3 is slow, a time required until the end of air/fuel ratio detection can be reduced.
ITSUJI TAKAYUKI
MIKI MASAYUKI
ISAMIGAWA FUMIO
UCHIDA MASAAKI
NISSAN MOTOR
| JPS62139944A | 1987-06-23 |