Working principle of diesel engine

Clean air is sucked into the cylinders of a diesel engine and subjected to strong compression. As a result, it heats up to about 600°C. At this time, shortly before the piston is at top dead center, diesel fuel is injected, which flares up from the heat. In this case spark plugs are not needed.

With a cold engine, it may happen that the temperature of the compressed air is insufficient to ignite the diesel fuel. Then the fuel is additionally heated. To do this, each swirl chamber has a glow plug. Fuel is taken in by a high pressure distribution pump (injection pump), directly from the fuel tank. It creates a high pressure, about 135 bar, required to inject fuel into the cylinders, in the order they work. At the same time, the injection pump regulator doses the amount of fuel, depending on the position of the gas pedal. Through the injectors, the fuel enters the prechamber of the corresponding cylinder in a timely manner. The intake air, on the compression stroke, is assured and mixed with the injected fuel, creating an optimal combustible mixture.

Before fuel enters the injection pump, it passes through the fuel filter. It contains dirt and water. Therefore, it is especially important to change the fuel filter in accordance with the maintenance instructions.

The injection pump is not serviced. All moving parts of the pump are lubricated with diesel fuel. The injection pump is driven by the crankshaft through a toothed belt, which also drives the camshaft.

Since the diesel engine cannot be turned off by turning off the ignition, it has a solenoid valve. When the power is turned off, the voltage supply to the valve is interrupted, and the valve closes the fuel supply channel. This cuts off the fuel supply before locking the steering lock. When the engine is started, voltage is applied to the solenoid valve and the fuel supply channel opens.