Patent attributes
A fuel injection device for supplying high-pressure fuel to an internal combustion engine includes a fuel supply pump, a first common rail and a second common rail. High-pressure fuel is directly supplied to the first common rail and then to the second common rail from the first common rail through a connecting passage having an orifice. The high-pressure fuel accumulated in the common rails is supplied to injectors and is injected into cylinders in a controlled manner. To suppress pressure wave propagation from the first common rail to the second common rail while providing an appropriate flow passage size, a passage diameter of the orifice is set to 0.9 mm–1.3 mm. In this manner, a pressure difference between the first common rail and the second common rail is minimized.
