| 摘要 |
<p>A fuel metering unit (FMU) comprising a metering valve (28) operable to control the supply of fuel to a delivery chamber (58) of a pressure raising valve (PRV) (52), the PRV (52) including a valve member (54) movable under the influence of the pressure within the delivery chamber (58) between a closed position and an open position in which fuel is able to flow from the delivery chamber (58) to an outlet port (62), and a push-piston (72) movable under the influence of the pressure within a control chamber (74) to urge the valve member (54) towards its open position, wherein the control chamber (74) communicates with a valve control port (82, 83).</p> |
