FUEL INJECTION CONTROL APPARATUS AND CONTROL METHOD THEREOF

摘要

A fuel injection control apparatus has a rail pressure sensor (43) and an electronic control unit (ECU) (52). The ECU (52) converts the common rail pressure (analog signal) detected by the rail pressure sensor (43) into a digital signal by an A/D converter (53, 55), and controls the injection amount and the injection pressure based on the converted rail pressure. During the injection amount control, the ECU (52) determines an injection period based on an injection amount instruction value and the rail pressure, and causes an injector (23) to inject fuel over the injection period. During the injection pressure control, the ECU (52) controls a supply pump (27) so that the rail pressure converges to a target pressure. Furthermore, the ECU (52) performs the sampling for computing a rail pressure for the injection amount control and the sampling for computing a rail pressure for the injection pressure control at different timings.