Patent ID: 7578280

Claim:
A fuel injection apparatus for an internal combustion engine comprising: a fuel injector equipped with an actuator and a nozzle needle, the actuator working to lift the nozzle needle to inject fuel into an internal combustion engine; and a controller working to control an operation of the actuator to change an amount of lift of the nozzle needle a given number of times for a target injection duration; wherein said controller changes the amount of lift of the nozzle needle while keeping a spray hole opened to spray the fuel for the target injection duration, wherein said controller determines a minimum amount of lift of the nozzle needle for the target injection duration so as to have a sectional area of a fuel flow path defined by the nozzle needle and an inner wall of a body of said fuel injector which is greater than a sectional area of an opening of the spray hole, wherein said controller changes the amount of lift of the nozzle needle in a cycle for the target injection duration and determines a cycle of a change in the amount of lift of the nozzle needle as a function of a pressure of the fuel supplied to said fuel injector, and wherein said controller changes the amount of lift of the nozzle needle in a cycle for the target injection duration and determines a cycle of a change in the amount of lift of the nozzle needle as a function of a temperature of the fuel supplied to said fuel injector.