FUEL INJECTION RATE CONTROL DEVICE FOR DIESEL-ENGINE

摘要

PURPOSE:To make it possible to reduce noise without being affected by variations among the kinds of engines, aging effects thereof or the like by controlling a pilot injection means so that combustion noise is made to be minimum in accordance with detected combustion noise. CONSTITUTION:A combustion noise detecting means 10 is composed of a microphone 11, a band filter circuit 12 for passing the output of the microphone only in an important frequency range and a peak-hold circuit 13. An analog signal from the means 10 is delivered to an A/D converter 34 in a microcomputer 3 which controls a fuel injection timing control means 5 so as to set the ignition timing of the engine to a desired ignition timing, and which receives a signal from the fuel noise detecting means 10 to control a pilot injection means 4. The pilot fuel injection means 4 receives a control signal from a microcomputer 3 so that a piezo drive circuit 41 charges and discharges a piezo actuator 40, thereby it is possible to control the pilot fuel injection amount and the rest time from the pilot injection and the main injection.