BOUGIE D'ALLUMAGE REQUERANT UNE TENSION DE DECHARGE FAIBLE ET PRESENTANT UNE CAPACITE D'AUTONETTOYAGE ELEVEE

The minimum distance, G1, between the terminating edge of a thin component (42) of a central electrode (4) and the internal edge of a projection (52) of an earth electrode (5) is greater than or equal to the distance, L, between the thin component and the projection. The sum of the minimum distance, G2, between the terminating edge of an insulator (3) and the external edge of the projection and the distance, H, between the end of a base component (41) of the central electrode and the end of the insulator is greater than G1. The ratio of G2 to G1 is less than or equal to 1.5. The thin component in the central electrode is connected to an end of the base component (41) that is fitted into a drilling (32) of the insulator which is held in a metal covering (2). The earth electrode includes a base component (51) fixed to the metal covering, and the projection that is connected to the base component (51) and points towards the thin component. The internal edge of the projection is positioned nearer the axle of the thin component than the external edge of the projection. The product of the radius, R3, of the thin component and 0.7 is less than or equal to the distance, R1, between the axis of the thin component and the internal edge of the projection. The distance, R2, between the axis of the thin component and the external edge of the projection is greater than or equal to the product of 0.5 and the radius, R4, of an end of the drilling in the insulator but less than the product of 1.2 and R4.