| 摘要 |
A fuel injection pump including a pump piston, which pumps fuel at injection pressure to an injection nozzle as long as a control valve blocks the flow of the fuel, which overflows from the pump work chamber via a flow conduit, to a low-pressure chamber. In this operating state, if the control valve jams and the supply of fuel to the pump work chamber is not completely prevented. A Venturi pump is provided to evacuate the fuel. By means of the Venturi pump with a permanent flow of fuel through it, the static pressure is partially dropped at a flow throttle and this negative pressure is utilized at bottom dead center (UT) of the pump piston to evacuate the pump work chamber by suction, thereby preventing an unintended injection. The apparatus is especially suitable for high-pressure injection in Diesel engines, to achieve redundantly safe operation.
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