Why Don't Diesel Engines Use Spark Plugs for Ignition?

[Amir]

Diesel vehicle engines employ a compression ignition method, which differs from gasoline engines in that they do not have a spark plug structure. During operation, air enters the cylinder of a diesel engine. When the air inside the cylinder is compressed to its peak, the temperature can reach 500-700°C, causing the mixture of air and diesel fuel to reach its ignition point and spontaneously combust. Composition of a Spark Plug: A spark plug primarily consists of a terminal nut, insulator, terminal stud, center electrode, side electrode, and metal shell. Main Types of Spark Plugs: Standard spark plugs, extended insulator spark plugs, electrode-type spark plugs, seat-type spark plugs, pole-type spark plugs, and surface-gap spark plugs. Working Principle of Spark Plugs: The ground electrode of a spark plug is connected to the metal shell, which is threaded into the engine block via the cylinder head. The insulator primarily serves to isolate the metal shell from the center electrode. The terminal nut is the part of the spark plug that contacts the high-voltage coil. When current passes through the terminal nut and the center electrode, it ionizes the medium between the center electrode and the ground electrode, generating a spark to ignite the air-fuel mixture in the cylinder.