A fuel injection device is provided which can inject fuel by very high
injection pressure and can realize favorable combustion and exhaust
characteristics, and moreover, enables performance of fuel injection with
arbitrary fuel injection patterns. In the fuel injection device 30, the
protrusion 61 is provided at a distal end portion of the piston control
valve 60 which is provided at the pressure intensifier 54, can change a
practical opening area of the fuel flow path 57 to the cylinder 56 in
accordance with movement of the piston control valve 60, and can control
inflow amounts of liquid fuel that is flowed into the cylinder 56 by the
piston control valve 60 (does orifice control). Thus, control of injection
rates and injection pressures of fuel that is injected from the fuel
injection nozzle 34 is enabled, and fuel injection patterns can be
realized with an extremely high degree of freedom.
