| 摘要 |
<p>A rotary distributor type of fuel pumping apparatus has a distributor member 10 mounting cam actuated pumping plungers 14. During inward movement of the plungers an electromagnetically operable valve 32 is operated which when open allows fuel under pressure to open a spill valve 31. The spill valve includes a spring loaded piston 23 which has a projection 22 engageable with a seating to prevent escape of fuel from the pumping chamber. Fuel under pressure is allowed to act on the piston when the valve is opened. The piston is pressure balanced by a plug 27 which is slidable in a drilling 25 in the piston, the drilling being connected by a passage 26 to the pumping chamber. The plug is held against movement and its diameter is substantially equal to the seat area to achieve pressure balance.</p> |
