Patent ID: 8977472
Filing Date: 2015-03-10
Classification: F02D,Y02T

Abstract:
1. A fuel injection control system for a direct-injection engine comprising: fuel injection valves for directly injecting fuel into respective cylinders of the engine; and an electronic control unit for controlling fuel injections by the fuel injection valves to carry out a split injection, which includes a fuel injection in an intake stroke and a fuel injection in a compression stroke of the engine, wherein the electronic control unit includes: an injection-amount changing portion for gradually increasing or decreasing amount of fuel injection in the compression stroke when the split injection is carried out; a rotation detecting portion for detecting rotational speed of the engine, which is changed by combustion of the injected fuel, for respective fuel injections an amount of which is increased or decreased by the injection-amount changing portion; a compression stroke injection amount calculating portion for calculating the amount of the fuel injection, with which the rotational speed of the engine becomes maximum, and setting such amount as a compression stroke injection amount for the fuel injection in the compression stroke; and an injection controlling portion for controlling the amount of the fuel injection in the compression stroke based on the compression stroke injection amount, after the compression stroke injection amount has been calculated by the compression stroke injection amount calculating portion.