Power supply control for spark plug of internal combustion engine

Abstract

A method for controlling the power supply of a radiofrequency spark plug in an internal combustion engine up to an electric voltage sufficient for generating a highly branched spark. To this end, the electric voltage for powering the spark plug is increased step by step up to an adequate voltage adapted for ignition.

Description

technical field [0001] The invention relates to a method for supplying an ignition spark plug to a voltage which ensures the generation of a multi-firing spark, in particular a multi-firing spark of an internal combustion engine. [0002] The invention also relates to a device for supplying such a spark plug, comprising means for supplying the spark plug up to a voltage which ensures the generation of a spark with a plurality of ignition branches. Background technique [0003] For better control when igniting flammable mixtures in internal combustion engines, it is known to preferably use sparks of large size. Specifically, the larger the spark, the more likely the thermal arc will meet the fuel cloud and the ignition will be more efficient. For conventional ignition spark plugs, the size of the spark (approximately 1 cubic millimeter) is limited by the distance between the two electrodes of the spark plug. [0004] In order to increase the spark size of the ignition spark...

AI Technical Summary

Problems solved by technology

[0005] - In US-A-5623179 the distance between the electrodes of the spark plug is increased; however this solution requires a particularly large supply voltage which is directly proportional to the distance between the electrodes,

[0006] - In EP-A-1202411 or EP-A-1526618, the use of an electric arc sliding over the insulator of the spark plug, which makes it possible to lengthen the spark without increasing the voltage to a great extent; The lengthening can only be maintained for a relatively short time and the insulating surface contacted by the heat arc is damaged very quickly;

[0007] - In FR-A-2886776 or FR-A-2878086, a multi-filament radio-frequency spark is formed that spreads out from a single pointed electrode; this makes it possible to greatly increase the length of the spark, but in the known methods of this scheme, at the same time Limited number of filaments formed (up to 2-3)

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