| 摘要 |
PURPOSE:To eliminate any misconception on a decelerating state as well as to prevent the occurrence of hunting in a car speed, by discriminating the decelerating state from throttle valve opening and a period of engine pulses detecting an engine speed, while interrupting closed loop control over an air-fuel ratio in time of deceleration. CONSTITUTION:In case of a device which detects exhaust gas component content in an engine and feedback-controls an air-fuel ratio, engine speed and throttle valve opening are detected, and from a combination of these elements, a decelerating state of the engine is discriminated. For example, engine speeds N1-N4 are set down as a boundary value, an engine speed range is divided into five parts, and further it is divided into two part on the basis of a throttle opening value TH, then the whole range is divided into ten ranges (1)-(10). Of which, the range of (3) is discriminated as a decelerating range, and further at this time, closed loop control over the air-fuel ratio is interrupted, making it into open loop control. With this constitution, the decelerating state is surely discriminable and, what is more, hunting in a car speed is preventable. |
