| 摘要 |
PURPOSE:To prevent abnormal increase of an injection quantity and overspeed of an engine at occurrence of abnormality, by detecting the abnormality of a microcomputer and its peripheral circuits and switching an injection quantity command from a normal arithmetic quantity command to a subtarget injection quantity command. CONSTITUTION:The captioned device comprises a central processing unit (CPU)2, in which signals from detectors 1a-1g detecting an operational condition of speed, intake pressure, accelerator control amount, etc. are input to arithmetically obtain a target injection quantity of an engine. This CPU2 further compares a signal of the target injection quantity with a signal of an actual injection quantity detector 6 to correct its error by controlling an actuator and control an injection quantity of a fuel injection pump 1. At this time, an arithmetic circuit 8, calculating a subtarget injection quantity by a signal from said detectors 1a- 1g, and detector circuits 9, 10, detecting abnormality of the CPU2 and its peripheral circuits, are further provided in the CPU2, at detection of abnormality, a selector circuit 11 is switched to output a subtarget injection quantity signal. |
