According to the heating value, there are cold and hot types; according to the electrode material, there are nickel alloys, silver alloys and platinum alloys; if more professional, the types of spark plugs are generally as follows:
1.Quasi-type spark plug: its insulator skirt is slightly retracted into the end face of the case, and the side electrode is the most widely used outside the end face of the case.
2. Edge body protruding spark plug: The insulator skirt is longer and protrudes beyond the end face of the casing. It has the advantages of large heat absorption, good anti-fouling ability, etc., and can be directly cooled by the intake air to reduce the temperature, so it is not easy to cause hot ignition, so the thermal adaptation range is wide.
3. Electrode type spark plug: The electrode is very thin, which is characterized by strong sparks and good ignition ability. It can also ensure that the engine can start quickly and reliably in severe cold seasons. It has a wide thermal range and can meet various purposes.
4. Seat-type spark plug: Its housing and screw-in thread are made tapered, so it can maintain a good seal without a gasket, which reduces the size of the spark plug and is more beneficial to the design of the engine.
5. Polar spark plugs: The side electrodes are generally two or more. The advantage is that the ignition is reliable and the gap does not need to be adjusted often. Therefore, it is often used on some gasoline engines where the electrodes are easily ablated and the spark plug gap cannot be adjusted often.
6, surface spark-type spark plug: the surface gap type, it is the coldest type of spark plug, the gap between the center electrode and the housing end face is concentric.
7. Standard and protruding spark plugs
The standard spark plug is a single-sided electrode spark plug with the skirt end of the insulator slightly lower than the threaded end face of the housing. It uses the traditional firing end structure with the most widely used side valve engine. To distinguish it from the "prominent type" that came later, this structure is called the "standard type".
8.Single-sided and multi-sided spark plugs
The traditional single-sided spark plug has a significant drawback, that is, the side electrode covers the center electrode. When the high voltage is discharged between the two poles, the mixture at the spark gap will absorb the heat of the spark and form a "fire core" due to ionization being activated. The place where the fire core is formed is generally near the side electrode, and the heat will be absorbed by the side electrode, which is the "flame-extinguishing effect" of the electrode, which reduces the spark energy and reduces the flashover performance.
9.Ni-based alloy and copper core electrode spark plug
The most basic requirements for electrodes reaching into the combustion chamber are ablation resistance (electrical and chemical corrosion) and good thermal conductivity. With the development of materials science and technology, electrode materials have undergone the evolution of iron, nickel, nickel-based alloys, nickel-copper composites, and precious metals. The most common use today is nickel-based alloys. Generally, pure metals have better thermal conductivity than alloys, but pure metals (such as nickel) are more sensitive to chemical corrosion reactions to combustion gases and the solid deposits they form than alloys. Therefore, the electrode material uses nickel-based elements such as chromium, manganese, and silicon. Chromium improves the resistance to electrical corrosion, and manganese and silicon improve the resistance to chemical corrosion, especially the corrosion resistance of the highly hazardous sulfur oxide.
10.Ordinary type and resistance type spark plug
As a spark discharge generator, a spark plug is a broadband continuous electromagnetic radiation interference source. In order to suppress the strong interference of electromagnetic radiation caused by flashover to the radio field, protect radio communications and prevent malfunction of on-board electronic devices, countries around the world have accelerated the development of resistance spark plugs since the 1960s.
