| 摘要 |
PURPOSE:To inject high-pressure fuel by covering the outside of a nozzle cylinder with a casing opened at its lower end, forming a plunger chamber near the lower end between them, and operating the plunger with the inner pressure of a combustion chamber. CONSTITUTION:In a unit injector 1, when a lower flange 5 facing on the opening 12 at the lower end of a casing 4 receives the inner pressure of a combustion chamber and is operated, the lower face of an intermediate flange 6 is affected via the cooling water in the first enclosed chamber 8, and a plunger P between a nozzle cylinder 3 and the casing 4 is operated. The fuel in a plunger chamber 16 is fed by pressure into a needle valve housing chamber 20 via the operation of the plunger P, a needle valve 2 is pushed up against an injection complete pressure setting spring 25, and high-pressure fuel is injected through a nozzle hole 26. In addition, when the engine rotating speed is changed, a nozzle cylinder 3 is rotated by an injection quantity adjusting tool 24 via a governor device, thus changing the discharge stroke. Accordingly, high-pressure fuel can be injected by fully utilizing the pressurizing capability of the plunger. |
