This accumulating
fuel injection apparatus is provided with a
needle valve 6 adapted to open and close an injection
nozzle 11 having injection ports 14 in a lower end portion thereof, a balancing chamber 5 formed in a casing 2 so as to apply a fuel pressure to a head portion of the
needle valve 6, a supply passage including a slit 10 and used for supplying a fuel from a
fuel supply port 19 to the balancing chamber 5, a
discharge passage 20 comprising an orifice for discharging the fuel from the balancing chamber 5, and a
solenoid valve 22 adapted to open and close the
discharge passage 20, the lift of a valve disc 26 of the
solenoid valve 22 is controlled by a lift control means comprising a stopper 28 the position of which is controlled by a lift control mechanism 23. The opening area of the
discharge passage 20 comprising an orifice increases and decreases in accordance with the lift of the valve disc 26, and the lift of the
needle valve 6 is determined so that the opening area of the slit 10 facing the interior of the balancing chamber 5 increases and decreases correspondingly to the flow rate of the fuel passing through the discharge passage 20, the degree of opening of the injection
nozzle 11 increasing and decreasing accordingly.