Electrically controlled fuel injection apparatus for multi-cylinder internal combustion engines

Claim 1

An electrically controlled fuel injection apparatus for multi-cylinder internal combustion engines, in which each pump piston of a fuel injection pump, driven at a constant stroke by a drive cam of a camshaft and guided in a cylinder bore, supplies the fuel placed under injection pressure in an associated pump work chamber via a pressure valve to an injection nozzle until such time as a valve element of an electrically actuated overflow valve blocks the flow of the fuel overflowing from the pump work chamber via an overflow conduit to a chamber of lower pressure, said apparatus having an inlet opening of a filling conduit which is under the supply pressure p V of a supply pump, the inlet opening being closable by a first control face on the jacket face of the pump piston after a pre-stroke H V of the pump piston has been completed, and having an overflow opening in the wall of each cylinder bore serving as the discharge point of the oveflow conduit, the overflow conduits of at least two adjacent pump work chambers are interconnected and the return flow of fuel out of these overflow conduits to the chamber of lower pressure is controllable by the valve element of the overflow valve common to these overflow conduits, that the overflow conduits are each provided with a barrier valve, by means of which the at least one pump work chamber which is not under injection pressure can be blocked off from the pump work chamber which is under injection pressure at that time, and a second control face on the pump piston closing the overflow opening in one of the dead center positions of the pump piston acts as the barrier valve.