Patent ID: 7487762
Filing Date: 2009-02-10
Classification: F02M

Abstract:
1. A fuel injection system for an internal combustion engine comprising: a fuel injection apparatus for pressurizing low-viscosity fuel by using a plunger of the fuel injection apparatus to feed pressurized fuel to a fuel injection nozzle; a lubricity improver tank for holding a lubricity improver; a fuel tank for holding the low-viscosity fuel; a fuel supply pump for supplying the low-viscosity fuel from said fuel tank to said fuel injection apparatus; a lubricity improver supply means for supplying lubricity improver from said lubricity improver tank to the low-viscosity fuel from said fuel tank upstream of said fuel injection apparatus; and a controller for controlling said lubricity improver supply means so that (1) the amount of lubricity improver added to the low-viscosity fuel increases as engine speed, engine load or injection pressure increases, and (2) the amount of the lubricity improver that is added to the low-viscosity fuel is controlled in response to an increase in the amount of the lubricity improver that is in said fuel tank due to partial return of the low-viscosity fuel containing the lubricity improver to said fuel tank from said fuel injection apparatus.