Fuel injection control device for internal combustion engine, has pressure reducing device executing opening function of pressure regulating valve if preset value is equal or more than difference between fuel pressure and desired pressure

摘要

The device has a pressure accumulating chamber (10) for storing fuel at a high pressure level, and a pressure regulating valve (18) for leaving out the fuel into the chamber. A fuel injection valve (14) injects the fuel stored in the chamber. A pressure reducing device executes the opening function of the valve (18), when a preset value is equal/more than the pressure difference between the fuel pressure in the chamber and a desired fuel pressure. The valve (18) is open for a predetermined permitted time period, when the predetermined value is equal or more than the difference pressure, and another predetermined value is less than the difference pressure. The value (18) is open for another permitted time period, when the latter value is equal or more than the difference pressure.