Patent ID: 8825343

Claim:
A fuel injection control device of a diesel engine including a fuel injection valve which injects a fuel into a combustion chamber and a fuel injection timing control unit which controls a fuel injection timing of the fuel from the fuel injection valve, the fuel injection control device comprising: a standard fuel injection timing setting unit which previously sets a standard fuel injection timing with respect to engine speed and fuel injection quantity; a penetration judging unit which judges whether or not fuel spray penetration in a cylinder is in an increasing condition, by using an estimated cylinder pressure at an injection start timing; and a fuel injection timing correction unit which, by correcting the standard fuel injection timing toward an advanced timing angle, constrains the fuel spray penetration when the penetration judging unit judges that the fuel spray penetration is in an increasing condition, wherein the estimated cylinder pressure at the injection start timing is computed based on pressure in an intake manifold, and wherein the penetration judging unit judges that the fuel spray penetration in the cylinder is in an increasing condition when the estimated cylinder pressure is lower than a standard cylinder pressure at the injection start timing according to the standard fuel injection timing.