Fuel injection controller

摘要

A fuel injection controller is provided with a detection control portion which detects a valve-opening time. The detection control portion supplies the low valve-opening voltage to the fuel injector from a low voltage supply. An electric current flowing through a coil is gradually increased. When the fuel injector is fully opened, an inflection point appears on a waveform of an electric current. A valve-open detecting portion detects the inflection point and identifies a valve-opening time. A correction-amount computing portion computes a correction amount of a fuel injection quantity due to an error of the valve-opening time. In a succeeding fuel injection, the correction portion corrects an electric supply period. As a result, the error of the fuel injection quantity due to an error of valve-opening time is corrected.

主权项

1. A fuel injection controller which has terminals connectable to a coil of a fuel injector, comprising:
a usual-control portion which supplies a high valve-opening voltage to the terminals in order to perform a first-speed fuel injection by the fuel injector; a detection control portion which supplies a low valve-opening voltage lower than the high valve-opening voltage to the terminals in order to perform a second-speed fuel injection by the fuel injector, the second-speed fuel injection being different and less than the first-speed fuel injection; a valve-open detecting portion which detects the fuel injector is positioned at a full-open position during the second-speed fuel injection by detecting an inflection point on a waveform of an electric current flowing through the coil only when the low valve-opening voltage is supplied, the valve-open detecting portion identifies a valve-opening time at which the fuel injector is positioned at a full-open position during the second-speed fuel injection; and a correction processing portion which corrects a parameter in a succeeding fuel injection performed by the usual-control portion, based on the valve-opening time of the second-speed fuel injection detected in a preceding fuel injection performed by the detection control portion so that an error of a fuel injection quantity due to an error of the valve-opening time in the succeeding fuel injection performed by the usual-control portion is decreased.