| 摘要 |
The igniter (21) comprises a metal shell (22) having a firing end (23) which terminates at its lower end in an annular ground electrode, an insulator (27), a centre electrode (25) and a plurality of oxidation and erosion resisting inserts embedded within and bonded to the metal shell (22). The insulator (27) is sealed within the metal shell (22) and has a central bore within which the centre electrode is sealed and a lower surface extending inwardly toward the bore from the ground electrode. The centre electrode (25) is so positioned that a spark discharge between it and the ground electrode occurs along the inwardly extending surface of the insulator (27). The inserts are composed of iridium, platinum, rhodium, ruthenium, osmium, tungsten or an alloy or ductile alloy of one of the foregoing metals. <IMAGE> |
