Abstract: To obtain an input speed signal (U.sub.n) for use as a feedback signal in an electronic diesel control (EDC), averages are taken by a component (12) of successive speed signals (n) produced by reference marks (BM) on the engine crankshaft. An extrapolator (10) estimates, by linear extrapolation, the average value for a given instant from the last average produced by the component (12) and from the previously calculated average stored in a memory (14).Higher frequency speed fluctuations due to the momentary engine combustion pressures are eliminated from the output signal (U.sub.n) while avoiding any significant phase delay between the input (n) and output (U.sub.n) of the lower frequency fluctuations arising owing to the existence of the oscillatory system comprising the engine and its resilient mounting.

Abstract: A pressure valve is proposed which is installed in the supply line which leads from a fuel injection pump to a fuel injection valve. The pressure valve has a return-feed collar provided with a throttle connection and a relief conduit is provided parallel to the return-feed collar and to the valve closing member sealing face. Via a check valve and a throttle, the relief conduit establishes the communication between the supply line toward the injection pump and the supply line toward the injection valve. By means of the combination of the return-feed collar having a throttle with a check valve acting as a pressure maintenance valve, a desired residual pressure can be established in an adapted manner in the supply line toward the injection valve, and the injection duration in particular can be adapted to the requirements of a fuel injection pump which pumps at a reduced feed rate during idling operation.

Abstract: A fuel injection apparatus having pre-injection and main injection and associated with Diesel engines is disclosed. A high-pressure injection pump delivers a main injection quantity to a main injection nozzle, and a hydraulic pre-injection auxiliary pump is driven by this same pressure pulse. The pre-injection auxiliary pump includes a stepped piston, comprising a pre-injection piston portion and a driving piston portion, and the stepped piston has as an integral component such as a slide pintle control valve located in an extension of its driving piston portion. This control valve opens the passage to the continuing pressure line and to the main injection nozzle only after a predetermined stroke of the stepped piston has been attained.