Spark Plug – SA002C

The spark plug is an important component of the ignition system of a fuel vehicle. It can introduce high-voltage electricity into the combustion chamber and cause it to jump across the electrode gap to generate sparks, thereby igniting the combustible mixture in the cylinder. The spark plug is mainly composed of a wiring nut, an insulator, a wiring screw, a center electrode, a side electrode and a shell. The side electrodes are welded to the shell.
When working, the spark plug not only has to withstand sharply changing temperature shocks, pressure shocks and chemical corrosion in the combustion chamber, but also withstands an ignition high-voltage pulse of at least 30,000 volts. Therefore, the spark plug must have intact mechanical, electrical and chemical properties throughout its life cycle.
The ceramic and electrode materials of the spark plug must have sufficient mechanical strength to withstand the combustion explosion pressure impact of 80 bar, and at the same time, it can absorb the temperature alternating impact of gas as low as 40°C and combustion gas as high as 2500°C.
The ceramic of the spark plug must be able to withstand an ignition high-voltage pulse impact of at least 30KV (30,000 volts) without being broken down, and flashover creepage must not occur on the ceramic surface.
Ceramics and electrode materials must be able to withstand the chemical corrosion of combustion products (PbPs compounds),
The calorific value of the spark plug must be selected to match the engine. Improper calorific value matching may cause melting of the ceramic or electrode behind the spark plug, or carbon deposition due to overcooling.
When selecting a spark plug, in addition to confirming the thread specification and ignition end size, be sure to select a spark plug with the appropriate calorific value!
It refers to the ability of the spark plug to resist carbon deposit failure under low-temperature and low-speed operating conditions (for example, the speed is less than 40KM/H). It is usually assessed by multiple repeated starting tests of the vehicle under low-temperature conditions. The factors that affect carbon deposition performance are relatively complex, mainly including the following aspects:
A. Mixed gas concentration: determined by ECU numbers. Under low speed and small load conditions, if the mixed gas is too concentrated, carbon will accumulate.
B. Driving habits: If the vehicle is operated under low speed and small load conditions for a long time, carbon deposits will be serious.
C. Fuel quality: Inferior quality fuel cannot be fully burned and can easily cause carbon deposits.
D. Spark plug temperature: When the working temperature of the spark plug is lower than 500°C, carbon deposits will always occur.
E. Spark plug skirt structure: Optimizing the skirt and top structure of the ceramic can improve the carbon deposition phenomenon.
Common problems with improper spark plug installation:
Ceramic cracks, six-party damage.
The torque is too large and the threads will crack or break.
The torque is too small, the gasket is not deformed, and the electrode is overheated and broken.
There are corresponding specifications for spark plug installation sleeves, specifically ISO11168:95. However, it should be noted that the original specification was that the minimum hexagonal size of the spark plug was only 16mm. The specification stipulates that the 14mm corresponding specification is not applicable to spark plugs. It is recommended that the 14mm corresponding spark plug sleeve refer to the 16mm corresponding design to avoid damage to the ceramics during installation.