| 摘要 |
PURPOSE:To regulate an amount of fuel injection correctly, by forming a fuel discharge groove at the outer periphery of a piston and providing a discharge valve communicating with the groove at a fuel discharge portion to improve fuel cutting-off when an fuel injection has completed. CONSTITUTION:When a 3-way electromagnetic directional control valve 4 is exited at any desired timing to cause a hydraulic fluid chamber 6c to be communicated with a oil passage 10, high pressure hydraulic oil flows into the hydraulic liquid chamber 6c from a pressure accumulator 3. A pressing force to the lower surface of a piston 12 of large diameter applied by the pressure of the hydraulic fluid overcomes the urging force of a return spring 6e thereby to move a piston member 18 upwardly. As a result, fuel in a fuel supply chamber 6d disposed above a piston 13 of small diameter is pressurized to be injected into an engine combustion chamber from a fuel injection valve 11 through a fuel passage 10. A part of the fuel is discharged from the fuel supply chamber 6d through a fuel discharge passage 13b, a fuel discharge groove 13a and a fuel discharge portion 15 by pressing a discharge valve 16, whereby pressure remaining in the fuel passage 10 is removed promptly. |
