PRESSURE ACCUMULATION TYPE FUEL INJECTION DEVICE

PURPOSE: To prevent a supply pump from being overloaded, by releasing suction with a minimum demand volume in a suction pipe of a pump through a throttle when the pressure in an accumulator reaches a maximum value, and by partially communicating the pressure pipe with the suction pipe. CONSTITUTION: A supply pump sucks up fuel from a suction pipe 15 through the rotation of an eccentric cam 14, and supplies pressurized fuel into an injection nozzle 7 through operation of a magnet valve 8 through a check valve 5, an accumulator 3, a pressure pipe 4 and a supply pipe 6. In a maximum charge condition of the accumulator 3, although the accumulator piston 17 ascends overcoming a sprint 18, a passage 20 in a spool valve 19 ensures a minimum cross-sectional area of the suction pipe 15 so as to partly communicate the pressure pipe 4 with the suction pipe 15 in order to prevent the pump from racing. Further, when the accumulator piston 7 comes to a position where a maximum accumulating pressure is obtained, the flow-out cross- sectional area 22 is opened, and fuel in a minimum discharge volume flows out through a return pipe 23 so as to cope with heating operation when the injection volume approaches zero, in order to prevent the temperature from being abnormally increased. Thereby it is possible to prevent the supply pump from being overloaded.