The high voltage generated by the ignition coil is introduced into the engine cylinder, and spark ignites the mixture between the gap of the spark plug electrode.
At present, spark plugs are usually divided into resistance spark plugs, wave gold spark plugs and iridium spark plugs.
Generally speaking, the life span of the resistance spark plug is 20 thousand kilometers, the lifetime of the sparking plug is 40 thousand kilometers, and the life of the iridium gold spark plug can reach 6 to 80 thousand kilometers. Therefore, the original spark plug of the low-end vehicle is a resistive spark plug, while the original spark plugs of luxury cars and high-end models are mostly iridium spark plugs.
According to the different material of spark plug, the type of spark plug can be divided into common copper core, yttrium gold, platinum, iridium gold, platinum and iridium alloy spark plug. The service life of these types of spark plugs is different, and the corresponding replacement mileage is also different.
How to make sure that the life of the spark plug expires and how often does the spark plug change? Whether the spark plug needs to be replaced and removed to check it, see whether the color of the burning, the gap between the electrodes, the gap between the porcelain body and the metal shell is leaking, and so on.
Taboo for use of spark plugs
1, avoid long-term unclean carbon accumulation.
In the use of spark plugs, the electrode and the insulation of the skirt have normal carbon accumulation. If these carbon deposits are not clean for a long time, the more it will accumulate, which will eventually lead to the leakage of the electrode or even the fire. Therefore, carbon deposition should be regularly removed and not cleaned until the spark plug is not working. There are seven major hazards in the use of automotive spark plugs.
2, avoid long term use.
There are many types of spark plugs, but they all have their own economic life, and if they are still used after the economic life, it will not be beneficial to the power and economy of the engine. It is shown that with the prolongation of the use period of the spark plug, the end face of the central electrode will change to the shape of the arc, and the side electrode changes to the shape of the concave arc. This shape will increase the gap of the electrode, and cause the discharge difficulty, which affects the normal work of the engine.
3, avoid random descaling.
Some people do not pay attention to the cleanliness of the spark plug when they spray silver powder or other maintenance on the engine, causing the spark plug to leak because of its dirty appearance. When cleaning the appearance, it is not convenient and quick to use sand paper and metal sheet to remove the scale, but the spark plug should be immersed in the gasoline, and the brush will be used to clean it to ensure that the ceramic body of the spark plug is not damaged.
4, avoid fire.
In reality, some people often use fire to remove the spark plug electrodes and the carbon and oil of the skirt. This seemingly effective method is actually very harmful. The temperature is difficult to control because the fire is burning. It is easy to burn the insulator of the skirt and cause the leakage of the spark plug, and the small cracks produced after the fire are often not easy to find, which brings a lot of trouble to the troubleshooting. The correct treatment of the coke and oil on the spark plug is to clean with a special equipment, and it will have a good effect. Two is the cleaning of the solution, the spark plug is soaked in alcohol or gasoline for a certain time, and then the carbon is softened and then the brush is used to dry.
5, avoid cold and hot.
Apart from the different shapes and sizes, spark plugs are also divided into three types: cold type, medium type and heat type. In general, a cold spark plug is suitable for a high compression ratio and high speed engine, while a low compression ratio and a low speed engine should be with a hot spark plug, and a medium spark plug is between them. In addition, the spark plug type selection of new engine or overhaul engine and old engine can be different according to the actual situation. For example, when the engine is new, the choice of spark plug tends to be hot; the old engine of the headmaster is prone to excessive carbon accumulation and oil fouling because of the decline in performance. The spark plug should be used to medium or cold type to improve the ability of the spark plug to resist oil pollution.
6, avoid misdiagnosis and misdiagnosis.
When the new spark plug is replaced or the fault needs to be checked, the spark plug should be dismantled and disassembled to observe the color characteristics of the electrode after the locomotive is running normally. There are several cases in the following cases:
First, the center electrode is reddish brown, and the side electrode and the surrounding gray green are suitable for the spark plug type selection.
The two is that there is an ablative or burning phenomenon between the electrodes, and the skirt and insulator are in a white state, which indicates that the type of the spark plug is overheated.
The three is the black stripe between the electrode and insulator skirt, which indicates that the spark plug is already leaking.
The proper spark plug should be re selected for improper selection or leakage of spark plug.
7, avoid installation too tight.
When the spark plug is installed, it must comply with the specified torque. When installing with a special tool, it usually does not exceed, but if it is too strong, excessive or with a plum spanner, it will often damage the spark plug porcelain core or screw the slider, the expansion slot breaks and causes the spark plug to be scrapped; but it can not be installed too loosely, otherwise the engine work will be abnormal.