One of the most famous elements of the starting system of a car - spark plugs, is probably familiar to everyone. Many have heard, but not many have seen. Spark plugs are designed to ignite the fuel mixture in the cylinder of an internal combustion engine.
Instructions
Step 1
Modern spark plugs are available in catalytic, arc, spark, and incandescent spark plugs. Spark plugs are used in gasoline engines. They are divided into classic, platinum, iridium, flare. Their unpretentious design has remained virtually unchanged over the past 50 years. Candles differ in the size of the head, the length and diameter of the thread, the type and number of electrodes, the gap between the electrodes and the heating number.
Step 2
Here are the main components of the plug: two electrodes (middle - contact and side - ground electrode), metal body with rolled thread, ceramic insulator with wave-like ribs, O-ring. Each element of the candle design ensures well-coordinated work of the entire mechanism. The middle and side electrodes have opposite charges and serve to close the electrical circuit through a spark. The metal body is involved in the heat sink.
Step 3
The ceramic fins of the insulator increase the resistance of the electrical circuit, lowering it at the middle electrode, and conduct the combustion heat to the cylinder head. They also protect against breakdown and voltage leakage on the car body. The sealing ring eliminates the ingress of combustible gas from the combustion chamber to the candle and the loss of pressure, compensates for other changing characteristics on the candle body and cylinder head. The molten glass noise suppression resistor provides the EMC required for the electronics. The inner seal is responsible for the tightness between the body and the insulator.
Step 4
This whole design is designed to ensure the passage of a high voltage (several tens of thousands of volts) through the candle, which occurs when an electrical circuit is closed through a spark, which repeats 500-3500 times per minute. The strength of the electric field that occurs in the gap between the electrodes is determined by their shape. For example, iridium and platinum candles with a thin and sharp central rod have a larger gap than in the classic version, which increases the tension, and, consequently, the breakdown strength. Thus, the degree of ignition and burnout of the fuel mixture, fuel consumption, efficiency and engine power, the level of harmful emissions into the atmosphere, etc., depend on the type of spark plug (gap size). But if the gap is too large, breakdown of the spark plug insulator and high-voltage wires is possible.
