Renault Vehicules Industriels

Denis Ranc

Yves Drutel

Marc Miettaux

Specific parameters of each of the injectors of the injection device of a combustion engine, especially a device with pre-injection with electronic control of a diesel engine, are determined. The curve of the instantaneous speed difference (DVi) of the engine shaft between the time of transition to the combustion top dead center point of the cylinder in question and a subsequent time preceding the transition to the combustion top dead center point of the following cylinder is established as a function of the value of the parameter to be determined, the other parameters of functioning being kept constant. The optimum value of the parameter is determined which corresponds to an extremum of the curve.

Process and device for determining the parameters of the fuel injectors

A detection device, for an injection pump of a motor vehicle engine, for measuring the speed of rotation of the engine, pinpointing angularly the top dead center corresponding to each cylinder of the engine and performing static timing of the injection pump. The device includes a multipolar ring of alternate polarity mounted on the rotation shaft of the pump inside the latter, the poles being grouped in a number of identical sectors corresponding to the number of cylinders of the engine; a sensor sensitive to magnetic field, mounted inside the pump opposite the ring; and an electronic processing interface connected, on the other hand, to the sensor, and on the other hand, to a computer for control of the electronic injection. The multipolar ring produces a varying magnetic field which is sensed by the sensor, and waveshaped and converted into a digital signal for application to a computer for control of electronic injection.

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Saint Priest, France

Denis Ranc