| 摘要 |
PURPOSE:To activate operation of an exhaust sensor immediately perform feedback control in a device of performing the feedback control of air-fuel ratio through output of the exhaust sensor, by feeding secondary air for a certain time to an exhaust line at open control. CONSTITUTION:A solenoid valve 5 is provided in an air introducing passage 3, mixing air into a fuel passage and controlling quantity of fuel, and said valve 5 is open-close controlled by a controller 6 to perform open control or feedback control of air-fuel ratio in accordance with input signals from an exhaust sensor 7, speed sensor 8, intake pressure sensor 9 and water temperature sensor 10. At this time, the controller 6 outputs a driving signal for a time T2 at each time T1 to a secondary air feed device 12 at open control in a range of feedback control, and secondary air is introduced to an exhaust pipe 11 to activate the exhaust sensor 7. In this way, output of the sensor 7 is inverted to obtain a feedback controllable state immediately start the feedback control. |
