Marine diesel engine accessories introduction What is the role of the injector

The fuel injector is very useful, it can change a certain amount of fuel from liquid to fog, and then mixed with air to provide the right mixture for the engine.

Different types of fuel injectors have different structures and characteristics. Like the shaft needle injector, the shaft needle can make the fuel spray in a ring atomization effect, and the reciprocating movement of the needle valve in the nozzle is not easy to block the nozzle. Ball valve injector valve rod hollow light weight, and automatic centering effect of high sealing performance.

There are two types of fuel injectors: open and closed. The high-pressure oil chamber of the open injector is directly connected with the combustion chamber through the jet hole, but the atomization is poor and used less. The closed injector has a needle valve partition between the two, and the small and medium-sized power high-speed diesel engine basically uses its common hole type and shaft needle type, the hole type is mostly used for the direct injection combustion chamber, and the shaft needle type is used for the separated combustion chamber.

The fuel injector must work up to certain requirements. There must be a certain injection pressure and range and the injection cone Angle must be reasonable. When the fuel injection is stopped, the fuel supply must be cut off quickly.

Fuel injector fixing methods are clamping plate fixing, hollow screw sleeve fixing and using its own flange fixing these three. Before assembly, the parts must be cleaned to check needle valve pairs and fuel injection bodies. When maintenance, first do spray quality and tightness test on the tester, if it is good, it does not need to be disintegrated, and if it is not good, it must be decomposed and repaired.

The electronic fuel injector is particularly critical and complex ECU in the common rail system, which allows the fuel in the high-pressure oil rail to be injected into the combustion chamber according to the optimal injection timing, injection amount and injection rate by controlling the solenoid valve to open and close.

The injector assembly is composed of a spray body, a couple, a push rod, a spring, a pressure regulating bolt and other components. Under normal conditions, when the needle valve closes the pressure oil under the action of the spring, it overcomes the spring elasticity to rise the oil injection, because the damping effect of the fuel spray. The injector responds to the ECU signal by pulling up the needle valve in the electromagnetic coil, opening the valve and injecting fuel to the engine cylinder in a timely and appropriate amount. The injected fuel and air are mixed to the cylinder ECU, which can also adjust the injection time and injection amount to obtain the best air-fuel mixing ratio.