Car Ignition Parts
The Automotive Ignition System is generating enough strong sparks to ignite the combustible fuel-gas mixture.
The requirements for the Ignition System,
It is required to generate enough voltage to break through the spark plug gap. That means the required voltage when the spark plug electrode breaks down to generate a spark is called the breakdown voltage. Then the secondary voltage generated by the ignition system must be higher than the breakdown voltage to make the spark plug spark.
The spark should have enough energy. To make sure reliable ignition, the high-energy electronic ignition system should generally have a spark energy of 80-100mJ, and the spark energy should be higher than 100mJ when starting.
The ignition timing should be adapted to the working conditions of the engine. First of all, the ignition system should be ignited in accordance with the working sequence of the engine. Secondly, the ignition must be carried out at the most favorable moment.
How Does The Car Ignition Parts Work?
The mainly working principle of the automobile ignition system is ignition coils and spark plugs.
An ignition coil can generate a high voltage enough to ignite a spark between the spark plug electrodes. Both the primary coil and the secondary coil surround the iron core. The number of turns of the secondary coil is approximately 100 times that of the primary coil. One end of the primary coil is connected to the igniter, and one end of the secondary coil is connected to the spark plug. The other end of each of the two coils is connected to the battery.
When the engine is running, according to the ignition timing signal (IGT) output by the engine ECU, the battery current flows to the primary coil through the igniter. As a result, magnetic lines of force are generated around the coil, which contains a magnetic core in the center.
When the engine continues to run, the igniter quickly stops the current flowing to the primary coil according to the ignition timing signal (IGT) output by the engine electronic control unit (ECU). As a result, the magnetic flux of the primary coil begins to decrease. Therefore, the self-inductance of the primary coil and the mutual inductance of the secondary coil generates an electromotive force (EMF) in a direction that prevents the existing magnetic flux from attenuating. The self-inductance effect produces an electromotive force of about 500V, and the accompanying mutual inductance effect of the secondary coil produces a high voltage electromotive force of about 30kV so that the spark plug generates a spark discharge. The faster the primary current is cut off, and the greater the primary current value, the higher the corresponding secondary voltage.
The high voltage generated by the secondary winding of the ignition coil generates a spark between the center electrode and the ground electrode of the spark plug to ignite the compressed combustible mixture in the cylinder. The spark produced on the spark plug ignites the air-fuel mixture, and this process is usually called combustion in automobile maintenance work.
The spark passes through the combustible mixture from the center electrode to the ground electrode. As a result, the combustible mixture is triggered along the path of the spark, generating a chemical reaction (through oxidation), and at the same time generating heat, forming the center of the flame.
The center of the flame triggers the surrounding combustible mixture, so that the heat in the center of the flame spreads outwards (called flame propagation) and ignites the combustible mixture. If the temperature of the spark plug electrode is too low or the electrode gap is too small, the electrode will absorb the heat generated by the spark. As a result, the center of the flame will be extinguished, causing a lack of fire. This phenomenon is called “electrode quenching.” If the electrode quenching effect is obvious, the center of the flame will be extinguished. The smaller the electrode, the smaller the quenching effect; the closer the electrode shape is to a square, the easier it is to discharge.
