A fuel injection system (injector) is a device that injects fuel into the combustion chamber of a diesel or gasoline engine. Engines generate power by causing fuel to combust explosively within the combustion chamber, which drives the pistons. For this explosive combustion to occur, the fuel must be atomized (turned into a fine mist) and mixed with air. Therefore, the injection system is used to spray fuel near the intake ports inside the combustion chamber. Fuel drawn up by the fuel pump installed in the fuel tank is delivered through the fuel line pipes under high pressure. Injectors are located at the ends of these fuel line pipes, from which the fuel is delivered into the engine's combustion chamber.
There are two main types of injectors: those that actuate a plunger via electrical signals, and mechanical types where the valve opens due to the high pressure of the fuel delivered by a mechanical injection pump. The specified injection volume of an injector is primarily determined by the hole diameter of the nozzle tip; the larger the hole, the more fuel can be injected at the same fuel pressure. Furthermore, even with the same nozzle hole diameter, a higher fuel pressure allows for a greater volume of fuel to be injected.
In piezo injectors, the opening and closing of the valve are controlled by electrical signals sent to a piezoelectric element, which regulates the plunger pressure. Piezo injectors are capable of faster operation than electromagnetic solenoid injectors. They inject the optimal amount of fuel according to the engine's displacement, performance, and the real-time RPM (revolutions per minute) and output torque.
