| 摘要 |
PURPOSE:To perform air-fuel ratio control high in reliability with high accuracy in a wide operating range by correcting change in the characteristics of an oxygen sensor due to exhaust gas temperature by means of a temperature compensating circuit of an air-fuel ratio controller, and thereby constituting a device to direct proper commands to an air bypass valve. CONSTITUTION:When an engine is in operation, oxygen concentration in exhaust gas is detected by the oxygen sensor 24 of a supercharger, and exhaust gas temperature in the oxygen sensor section 24 is concurrently detected by a temperature sensor 25, so that the outputs from both of the sensors 24 and 25 are inputted into an air-fuel ratio controller 26 so as to be processed. And the solenoid actuator 35 of an air bypass valve is drivingly controlled by means of the control signal obtained. In this case, the air-fuel ratio controller 26 is constituted to be equipped with a temperature compensating circuit 52 which corrects change in the internal resistance of the oxygen sensor 24 by means of an input impedance change-over switch 51, and with a temperature compensating circuit 57 and the like, which automatically corrects change in the output voltage of the oxygen sensor 24 due to exhaust gas temperature by means of automatically switching a set value based on exhaust gas temperature so that the set value is determined in response to exhaust gas temperature. |
