Spark Plug Characteristics
V-grooved center electrode spark plug
– Grooving is done at 90°for the center electrode and thus sparks are easily discharged.
– Since the sparks are discharged at near the periphery of the center electrode, there is less qeunching action of the electrode, and ignition performance is enhanced. Therefore, it is effective during engine start-up, idling and acceleration.
– Compared to the conventional plugs, the ground electrode is shortened to reduce its overlap onto the center electrode, thereby reducing the flame quenching effect and futher enhancing the ignitability. It provides for excellent breakage countermeasures by suppressing overheating of the ground electrode. This is the high preformance and long life plug which gives stable combustion with no abnomal combustion even in high compression engines.
Multi-ground electrode plug
(Example) BKR6EK – 2 ground electrode plug
(Example) BKUR6ET – 3 ground electrode plug
(Example) BKR6EQUP – 4 ground electrode plug
– Background of making the ground electrode multi-polarized is to ensure durability by distributing the electrode consumption. Multi-electrode plug is effective in improving the discharge characteristics (required voltage reduces).
– BKR6EQUP is a semi-surface discharge type plug. Sparks discharge along the insulator surface and burns away the carbon accumulated on the insulator. This plug has robust anti-carbon fouling performance.
Firing end-projection type plug
(Example) IZFR6K11 (Extended metal shell)
– Stable combustion can be achieved by moving the ignition position to center of the combustion chamber. However, if the projection type plug is used in engines other than those that have been specified, it will hit the piston or valve. Hence, it can only be used for specified vehicles.
– As for extended metal shell type, the ground electrode is designed shorter than the normal plug to reduce load due to heat and vibration.