| 摘要 |
PURPOSE: To improve fuel consumption by obtaining an unit injector in which a device limiting the amount of fuel injected during firing delay time with stopping the fuel injection by escaping the fuel, is arranged so as to reduce the combustion noise and to improve the exhaust emission. CONSTITUTION: An unit injector 12 is composed of a solenoid valve unit 24, a nozzle assembly 30, a plunger assembly 32 and a reduction chamber 36 in one body. The nozzle assembly 30 has a valve needle 46 that opens when the fuel pressure in the nozzle chamber 45 exceeds over the spring force of the pressure spring 48. The unit 24 has a spool valve 64 that is inserted in an inclined inlet bore 60 and is controlled by a solenoid 80, and the inlet 20 of the inlet bore 60 is connected to an outlet of a pump. Therefore, the connection of the passages 68, 70 that connect the nozzle chamber 45 and the plunger chamber 72 is controlled by the spool valve 64, so the plunger chamber 70 is compressible by the rotation of the cam through a tappet. |
