| 摘要 |
Injection pressure generated by a suitable flow source (16) and a pressure-flow regulator (28) is carried by a common rail or manifold (20) to each injector valve of an engine. The valves (22) are of the closed differential needle, hydraulic-operated type, opening and closing for the injection period by virtue of hydraulic pressure imbalance and balance exerted on the effective piston areas of the valve needle. Balance conditions are controlled by fuel flow through ports and orifices (72, 74, 78, 102) of electric solenoid-operated sliding spool valves (52) by an engine-driven timer device (38, 40) which controls the start and end of the injection period. Controlled by-pass flow from the spool valves (52) may be collected by a low pressure manifold for return to the reservoir along with the overflow from a high pressure manifold (20). |
