Spark plug

A spark plug, also referred to as an ignition plug, is a component that adds a spark sent to an electrode gap using high voltage generated by an ignition coil to a compressed air-fuel mixture to cause combustion.
Since these plugs are exposed to voltages of 1000V or more as well as high temperatures and high pressures when engines are running, they must have excellent heat resistance and insulation properties, etc.
Main parts consist of a plug, an insulator, and an electrode. The electrode is divided into a center electrode and an L-shaped electrode, and a gap suitable for creating sparks is provided between the two electrodes.
The heat spark plugs receive depends on engine operating conditions. Electrode temperature is low at low speeds, but rises at high speeds.
Therefore, heat dissipation is an important characteristic for plugs, and heat values are used to express to how well they dissipate received heat.
A spark plug whose temperature does not rise very much when used in an engine under the same operating conditions is called a high heat value (cold type) plug, while a plug whose temperature rises to high levels is called a low heat value (hot type) plug.
Generally, cold type plugs are used in the summer and under heavy loads, and standard or hot type plugs are used in the winter and other normal usage conditions.