The article discusses results of the laboratory experiments in which fuel injectors used in indirect injection internal combustion engines were tested. During the experiments, numerous dosing cycles of the injectors were performed while changing the control parameters, due to which, the dosing characteristics were developed and influence of applied parameters on the resultant fuel flow determined. Simultaneously, the voltage and electric current waveforms in the injector coil were recorded, due to which finding links between the electric current characteristics and the determinants of the injector work was possible. The investigation has shown that parameters of electric current constitute a precise criterion for assessing the operation of the solenoid valve, because fuel flow is created due to the work ofelectric current. Thus, by observing the changes in the current flowing through the valve coil,it is possible to monitor precisely the correctness of the process of opening the flow and the electric current intensity, at which the flow began and to determine the mechanical quantities such as fuel dose and pressure. As a result, a characteristic is developed, that provides the links between the fuel pressure and the electric current at the point of lifting the needle, which is quite a novel approach. Such a characteristic can be used in diagnostics and control of fuel injectors as well as all kinds of electromagnetic valves

The article discusses the method of evaluation of the fuel injector operation based on the observation of the electric current parameters, which were measured with a current transducer using the Hall effect, during the dosing process. This method relies on comparison of the electric current-related values of the examined injector with the model characteristics, which are representing the properly functioning injector. A model of the fuel injector in the form of the electric current waveform that describes the changes in the electric current and voltage during its work is presented in this article. Complex equations describing the fuel injector model under discussion account for the characteristics of the current variations, with no damage-induced modifications. Due to these, the modeled electric current/voltage waveform mirrors the real conditions. The use of a mathematical model describing the voltage–current phenomena occurring during the injector operation allows determining the actual beginning and duration of the injection. The model can also be used to develop new injector diagnostic methods that can be implemented in the engine controller (ECU).

This paper discusses a method of diagnosing electromagnetic valves of injection systems in combustion engines. Based on multiple analyses of electrical quantities occurring in the course of the electromagnetic injector work and physical relationships between them, the quantities have been demonstrated on which the fluctuation of the electromagnetic force in the injector depends. Moreover, the results of its fluctuations have been mapped to the electric quantities controlling the fuel injector’s work. The research has shown that the current and voltage waveforms contain information on electrical properties of the injector coil and its mechanical properties determining the injector’s technical health as well as that of the fuel system.

The article discusses mutual relations of the dosage characteristics, current intensity characteristics, and voltage characteristics in the fuel injector electromagnet. Changes in current in the electromagnet's coil were monitored in the course of dosage by means of the Hall sensor. Change in the Hall voltage is proportional to the changes in density of the magnetic flux generated around the injector coil during its work. The model of the current dependencies was used to determine the injector technical state in the actual time. The presented diagnostics proposition was created on the basis of the injector dosage characteristics obtained due to experimental research. Change in characteristic values, recorded during generation of the fuel dose allows for determination of the injector technical state, regarding both, the current-related and the mechanical parameters. Controlling in the actual time enables corrections in control parameters as a response to changes, as well as quick detection of damage resulting in switching the injector off the operation. This prevents the faulty operation of the injector, which may result in damage to subsequent components depending on its operation, such as the catalytic reactor.

In this article, the proposal for modelling the gas (fuel) injector based on observations of changes in the current during operation of the needle is presented. The aim of this work is indicating that the dosage characteristics can be mapped by means of the current characteristics. Moreover, observation of the current allows for determining the actual position of the needle. The time of the real fuel flow and the injector phase position can be determined with a microsecond resolution. The injector core inductance is a constant quantity but as a result of the needle movement and change in the permeability, inductance of the core varies depending on the needle position. These quantities, closely related to the current flowing through the coil, are described by means of differential equations resulting from the Kirchhoff's law, due to which changes taking place can be substantiated. Control of the flux enables the precise controlling of the injector in the actual time, thanks to the employment of fast analogue-digital converters and phase are taken into consideration.CHARAKTERYSTYKA PRĄDOWA WTRYSKIWACZA GENERUJĄCEGO DAWKI PALIWOWE Streszczenie W artykule zaprezentowano propozycję modelowania wtryskiwacza gazowego (paliwowego), na podstawie obserwacji zmian prądowych, w trakcie wykonywania pracy przez jego iglicę. Celem artykułu jest pokazanie, że można poprzez charakterystyki prądowe, odzwierciedlić charakterystyki dawkowania. Dodatkowo obserwacja prądu, pozwala określić aktualną pozycję iglicy. Możemy określić czas rzeczywistego przepływu paliwa i położenie fazowe wtrysku z precyzją mikrosekundową. Indukcyjność rdzenia wtryskiwacza jest wielkością stałą, ale w wyniku przesuwania iglicy i zmiany przenikalności, indukcyjność rdzenia zmienia się w zależności od położenia iglicy. Wielkości te, ściśle związane z przepływającym przez cewkę prądem, opisane są przez równania różniczkowe wynikające z prawa Kirchhoffa, dzięki czemu potrafimy uzasadnić zachodzące zmiany. Kontrola przepływu, pozwala na precyzyjne sterowanie wtryskiwaczem w czasie bieżącym, dzięki wykorzystaniu szybkich przetworników analogowo -cyfrowych i odpowiednich algorytmów. W sterowaniu uwzględniamy opóźnienia w działaniu impulsowego wtryskiwacza i przesunięcia fazy przepływu.Słowa kluczowe: indukcyjność, strumień magnetyczny, wtryskiwacz

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The aim of the work was to develop a method of real time diagnosing electromagnetic fuel injectors using the observation of electric current parameters available in the engine control unit. Performing this task required finding a precise criterion for assessing the correct operation of an electromagnetic injector. For this purpose, a mathematical model describing the individual phases of the injector's operation was used, allowing the simulation of the occurrence of typical failures. On its basis, symptoms of particular failures were determined based on the observation of electric current parameters in the control circuit. Observation of voltage and current waveforms allows to locate both electrical and mechanical damages to the injectors and to assess the correctness of the power system components. The presented diagnostic method allows the detection of the described damages in the early stages of their development, which prevents damage to the catalytic converter and other engine systems (valves, piston rings or cylinder surfaces), i.e. damages resulting from an incorrect fuel mixture.