Method of and an arrangement for controlling return quantities of exhaust

Abstract

A method and an arrangement for controlling exhaust return quantities of an automatic-ignition, internal combustion engine comprising a camshaft-driven piston injection pump and an exhaust control element in an exhaust return pipe. Pressure pulses occurring in an output pressure line of the injection pump during the injection-active delivery stroke are directly or indirectly detected as regards their pulse duration as the injection duration T.sub.E and their pulse intervals as the injection period T.sub.P. A certain injection stroke or a certain quantity of fuel to be injected per work cycle may be assigned, pump-specific, to each pair of values of these quantities through a known pump stroke curve. To control the return quantity of exhaust in dependence upon the quantity of fuel injected, the dependence between the pairs of values of T.sub.E, T.sub.P on the one hand, and control quantities for the return quantities of exhaust on the other hand, are stored in an at least two-dimensional identification field. Accordingly, it is possible for each pair of values of T.sub.E, T.sub.P determined in operation to retrieve the associated control quantity for the return exhaust quantities and to use that control quantity for controlling an exhaust control element. If the reciprocal value of the injection period T.sub.P is proportional to the rotational speed, other operating parameters, such as pressures and/or temperatures, may also be taken into consideration in the determination of the particular control quantity for the return quantities of exhaust.