Nickel Alloy / Silver alloy / platinum alloy
The seat type spark plug has a tapered housing and screw-in thread, 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.
Flat seat spark plug means that the contact surface between the spark plug and the cylinder is flat. Generally, the spark plug will bring a gasket by itself.
The cone-shaped spark plug is a cone-shaped contact surface, and generally does not have a gasket.
The so-called flat seat type, that is, the spark plug mounting seat (the large cylindrical end surface of the housing) is a flat surface, and there is an elastic sealing gasket between the flat surface and the cylinder during installation. For some engines, in order to be more compact or arrange more parts (such as adding valves), the spark plug is not left with a large installation space, which forces the spark plug to reduce the radial size, and even eliminates the outer sealing gasket, and uses a “taper seat” instead. The “flat seat”.
A conical mounting seat is adopted, that is, the spark plug housing has a conical surface with a taper angle of 63 °, and is matched with the conical hole of the cylinder head during installation, without the need for a sealing gasket. This conical fit requires extremely high concentricity between the conical surface and the thread diameter, otherwise it is difficult to guarantee the sealing performance.
1. Steel shell: The lower part of the steel shell is a thin thread for fitting with the cylinder head spark plug hole, and the upper part has an external hexagon nut for the spark plug sleeve to tighten or unscrew the spark plug. 2. The metal rod is the center electrode. The lower end of the metal rod is in contact with the upper end of the center electrode through a conductive glass body. 3. There is a high alumina ceramic insulator between the steel casing and the center electrode, so that the center electrode is insulated when the power is applied. 4. The lower part of the steel case is equipped with a curved side electrode. 5. There is a copper washer in the middle of the outer part of the steel shell.