| 摘要 |
<p>The system comprises, for each cylinder of the engine, an injector unit (2) with a metering and injection space (12) and a pumping space (14) which can receive respective masses of fuel, with a piston (15) for compressing the mass of fuel present in the metering and injection space (12) to effect its injection due to the pressure of the mass of fuel present in the pumping space (14). The two spaces (12, 14) in question communicate with pumping means (3,4) which generate a fuel pressure through a metering line (11) and a pumping line (9), operating at different pressures (23). A distributor element (38) is connected to the pumping line (9) and to a controlled-pressure discharge line (21) which in turn communicates with the metering line (11) through a one-way valve (142) preventing discharge of the pressurised fuel from the metering line (11). The distributor element (38) includes an obturator (42) movable between a first position in which the metering and injection space (12) is charged with fuel, and a second position in which the pumping space (14) of the injector unit (2) is put into communication with the pumping line (9) to effect the fuel injection operation.</p> |
