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1

Uniform spark plugs polarity in automotive ignition circuits equipped with double-ended ignition coils

Fryśkowski B.

Archiwum Motoryzacji

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2017

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Vol. 76, nr 2

63--74

EN

Automobile ignition systems with double-ended coils are classified under the group of distributorless ignition systems (DIS) family, used in the majority of contemporary vehicles. The characteristic feature of this type of system is the opposite (positive and negative) polarity of the central electrodes of spark plugs, being the load of the secondary winding of the double-ended ignition coil. The consequence of this is the difference in the peak value of the avalanche breakdown voltage of the gap between the spark plug electrodes - higher in the case of a positively polarized center electrode. The subject of this article is a technical solution that provides uniform polarity of the center electrodes of all spark plugs that constitute the load of the double-ended coil of the DIS. The polarity of the spark plug electrodes of all cylinders is particularly important in terms of measuring the leakage current of the insulator due to the aforementioned differential peak value at the gap between the electrodes. Uniform polarity of high voltage pulses also allows for conducting a series of comparative studies of the spark discharge energy on the plugs of individual engine cylinders. Such tests may be helpful in the case of attempts to identify the malfunctioning of the ignition coil secondary circuit, often leading to ignition misfire or increased fuel consumption.

PL

Samochodowe systemy zapłonu z cewkami dwubiegunowymi zaliczane są do grupy bezrozdzielaczowych układów zapłonowych wykorzystywanych w większości współcześnie użytkowanych pojazdów. Cechą charakterystyczną tego rodzaju układów jest przeciwna (dodatnia i ujemna) polaryzacja elektrod środkowych świec zapłonowych stanowiących obciążenie uzwojenia wtórnego dwubiegunowej cewki zapłonowej. Konsekwencją tego jest odmienna wartość szczytowa napięcia przebicia przestrzeni międzyelektrodowej świec zapłonowych – wyższa w przypadku elektrody środkowej spolaryzowanej dodatnio. Przedmiotem artykułu jest rozwiązanie techniczne zapewniające jednolitą polaryzację elektrod środkowych wszystkich świec stanowiących obciążenie cewki dwubiegunowej bezrozdzielaczowego układu zapłonowego. Biegunowość elektrod świec zapłonowych wszystkich cylindrów jest szczególnie ważna z punktu widzenia pomiaru natężenia prądu upływu izolatora ze względu na wspomnianą wyżej zróżnicowaną wartość szczytową napięcia przebicia przestrzeni międzyelektrodowej. Ujednolicenie polaryzacji impulsów wysokiego napięcia pozwala ponadto na przeprowadzenie serii badań porównawczych energii wyładowania iskrowego na świecach poszczególnych cylindrów silnika. Tego rodzaju badania mogą okazać się pomocne w przypadku prób identyfikacji nieprawidłowego działania obwodu wtórnego cewki zapłonowej, prowadzącego niejednokrotnie do wypadania zapłonów lub wzrostu zużycia paliwa.

2

An Analysis of Laser-Welded Nicr-Ir and Nicr-Pt Micro Joints on Spark Plug Electrodes in Biogas-Fuelled Engines

Grabas B., Tofil S., Napadłek W.

Archives of Metallurgy and Materials

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2016

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Vol. 61, iss. 2B

1163--1167

EN

The paper deals with the laser beam welding of tips to central and side spark plug electrodes made of a nickel-chromium alloy. The tips attached to the central electrodes were made from a solid iridium wire 0.8 mm in diameter and 2 mm in length, while the tips connected to the side electrodes were made from a platinum wire 1.5 mm in diameter and 0.25 mm in thickness. In both cases, accurate positioning of the tips was required before they were resistance welded to the electrodes. Then, a fillet weld was produced with an Nd:YAG laser using single, partly overlapping conductive pulses. The laser welding was performed at different laser power levels and pulse durations. Metallographic sections of the joints were prepared to observe changes in the microstructure and determine their correlation with the changes in the process parameters. The results were used to select appropriate welding parameters for the materials joined. The microscopic analysis indicated welding imperfections such as micro cracks at the interface between the elements joined. The tips welded to the spark plug electrodes can help extend the service life of spark plugs in highly corrosive environments.

3

The influence of impurities on the operation of selected fuel ignition systems in combustion engines

Różowicz S., Tofil S.

Archives of Electrical Engineering

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2016

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Vol. 65, nr 2

349--360

EN

The paper attempts to determine the impact of fuel impurities on the spark discharge energy and the wear of the spark plug electrode. Spark plugs were analyzed in two typical configurations of the ignition system. A number of tests were conducted to determine the wear of the spark plug electrode exposed to different types of impurities. The spark discharge energy for new and worn spark plugs was determined through calculation.

4

Positive linear dynamic model of mobile source air pollution and problems of control

Rumchev V.G., Caccetta L., Kostova S.

Systems Science

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2003

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Vol. 29, nr 1

31-46

EN

A dynamic model of mobile source air pollution (MSAP) is developed in this paper. The model exhibits positive linear system behaviour. One of its specific features is that the system is restricted to evolve in a given polyhedral region in the state space in order to keep the total emissions from the vehicles within the allowed levels. Three problems of control namely maintainability, finite-time holdability and feedback holdability are formulated and the corresponding solution procedures developed in the paper. A policy implementing the solutions to these problems leads to sustainable levels of the total emissions. Our method can be immediately used to support the decision making process of regional and state environmental authorities.