| 摘要 |
PURPOSE:To control exhaust gas of an engine and reduce its fuel consumption, by controlling supply air fuel ratio to a lean side in a light load-low speed range of the engine while to theoretical air fuel ratio in the other range after a feedback control condition is established. CONSTITUTION:An air flow meter 15, rotary speed sensor 29, intake air temperature sensor 58, water temperature sensor 59 and O2 sensor 60 are connected to a controller 50, consisting of a central processing unit (CPU)51, A/D converter 55, I/O device 56, etc. Then intake air quantity set values B, C, (B>C), basic injection quantity TP, constants K1, K2, (K1>K2) are set to a prescribed value. After establishment of a feedback control condition is decided by the CPU51 on the basis of detecting outputs of each sensor, if an intake air quantity Q is decided smaller than the set values B, C, the constant K1 or K2 is multiplied to the basic injection quantity TP to calculate an injection quantity TAU. In this way, lean control is performed in light load-low speed ranges Z2, Z3, while theoretical air fuel ratio control is performed in a high load-high speed range Z1. |
