FUEL INJECTION CONTROL SYSTEM FOR INTERNAL COMBUSTION ENGINE

摘要

The present invention addresses the problem of providing technology with which the saturation vapor pressure of the fuel being used can be detected in a fuel injection control system for an internal combustion engine equipped with a low-pressure fuel pump and a high-pressure fuel pump. To solve this problem, the present invention is a fuel injection control system for an internal combustion engine that performs proportional-integral control (PI control) with respect to the drive duty of the high-pressure fuel pump on the basis of the deviation between the discharge pressure and a target pressure for the high-pressure fuel pump, wherein the generation of vapor is detected from the change tendency of the integral term (the I-term) used in the proportional-integral control, and the saturation vapor pressure for the fuel being used is calculated on the basis of the fuel temperature, the engine rotational frequency, and the like when the generation of vapor is detected.