4 Injection Pump functions in conventional diesel engines
The injection pump or fuel injection pump is an important component in the diesel engine fuel system. Yes, as the name implies, the injection pump has a role in pumping fuel into the injector nozzle so that the nozzle can inject high-pressure fuel into the engine cylinder.
The primary function of the injection pump on a diesel engine is to pump fuel to the injector nozzle, but several other functions are also very important for the engine.
It is necessary because, in car engines, there are many sudden changes in engine speed, so the injection pump needs to have the ability to adjust to these changes and keep the engine functioning and comfortable to use.
So what are the functions of the injection pump on this diesel engine? Below is the function of the injection pump on a diesel engine.
1. Sucking fuel from the fuel tank
The first function of the injection pump in the diesel engine is to suck fuel from the fuel tank. This function is performed by an injection pump component called the priming pump.
Priming pumps on injection pumps are installed together, and some are installed separately. In-line injection pumps are generally installed together, while distributor injection pumps are often installed separately.
A priming pump is used to suck fuel from the fuel tank (fuel tank) into the injection pump. In addition, the priming pump also ensures that the incoming fuel is free of air bubbles that can interfere with the fuel injection process.
That way, the fuel will be sucked into the injection pump without stopping. With that, the injection pump can maintain the fuel supply needed by the engine.
2. Supplying high-pressure fuel to the injection nozzle
The second function of the injection pump on the diesel engine is to supply high-pressure fuel to the injection nozzle (injector nozzle). Yes, diesel engines require high fuel pressure so that the injector nozzle's fuel atomization process can occur ideally.
With perfect fuel atomization, it will also create perfect combustion in the engine cylinder, which also impacts producing optimal engine power.
Inside this injection pump, there is a plunger component that can press and push the fuel to the delivery pipe. As long as the engine rotates, the plunger will continue to pump fuel to create pressure in the fuel.
Valves are used before the delivery pipe to prevent the fuel pressure from dropping, which causes fuel to re-enter the plunger when the plunger moves down.
That way, every time the plunger pumps fuel into the delivery pipe, the fuel pressure will increase and get higher. After that, the high-pressure fuel is then channeled by the injection pump to each injector nozzle via a delivery pipe.
3. Set the fuel spray time
The third function of the injection pump on the diesel engine is to regulate the time of spraying fuel into the engine cylinder. In diesel engines (conventional), the injection pump will set the injection timing so the injector nozzle can spray high-pressure fuel into the engine cylinder. The injector nozzle carries out spraying based on the pressure generated by the injection pump.
As we know, the conventional type of injector nozzle will open the valve to spray fuel when the applied pressure exceeds the spraying pressure limit.
The injection pump will play a role in regulating the pressure to the delivery pipe that will be given to each injector nozzle so that when the injection timing approaches, the fuel pressure is sufficient, and the injector nozzle can inject fuel into the engine cylinder.
In addition, the injection pump will also choose a nozzle that will spray fuel into the engine cylinder. This condition is generally determined based on the diesel engine firing order according to the number of cylinders and the engine configuration used.
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4. Regulates the amount of fuel injected
The last function of the injection pump on a diesel engine is to regulate the amount of fuel injected. In the injection pump, the plunger has an important role in regulating the distribution of fuel to the injector nozzle. The plunger is also often used to regulate the amount of fuel injected into the engine cylinder.
Setting the amount of fuel in the plunger is moved by a control rod or rack component related to the load and engine rotation speed. When the engine requires a large amount of fuel, the control rod or rack will shift the plunger to open the fuel valve to allow more flow into the injector nozzle.
That way, the injection pump can adjust the amount of fuel injected into the engine according to the changes and fuel requirements required by the engine.