| 摘要 |
A pump including a floating piston (64) mounted in a cavity of a cylindrical body (32) rotated by a shaft (14). A timing chamber (62) and a metering chamber (60) are formed on either side of the floating piston (64). The amount of fuel admitted to either chamber (60, 62) is controlled by a single electromagnetic valve (20). The duration of energization of the valve (20) determines the fuel supply to the chamber (60) from a supply annulus (40) through passageways (82, 84, 86, 88). Upon completion of fuel metering into the chamber (60), the valve (20) is de-energized and the fuel is admitted from the supply annulus (40) into the timing chamber (62) and also by means of a passageway (72) to the opposing faces of a pair of pumping plungers (66, 68) forcing them outward towards a predetermined position. For initiating injection the plungers are forced radially inward by an annular cam (80), thereby increasing the pressure within the timing chamber (62) and displacing the floating piston (64), thereby forcing the fuel out of the metering chamber (60) into a discharge connection. |
