What is Unit Pump Injector?
The systems for direct injection of diesel are called unit pump injector system. In this system, each cylinder of the engine has a separate pump. Based on a special design, this system offers users various advantages.
Unit Pump Injector Operation;
There is no high pressure pump in this system. There is a feeding pump in the cover part of the cylinder. This pump sends the fuel to the injector part. The fuel increases by the injector pump to a total pressure of 2500 bar. This pressure is sent to the combustion chamber. There is one injector pump for each cylinder. There is also an injector for each pump. The unit pump injector system can also be explained as follows:
The pump piston continues to descend. At this time, the main injection occurs. Excess fuel will be sprayed. If the solenoid valve interrupts the current, the spring will push the pin back and the outlet hole will be opened. The high pressure fuel in the pressure chamber will enter the return line, the pressure will drop, the needle spring will press the needle, the nozzle hole will close and the spray will be finished.
What the Unit Injector Pump is for?
The unit pump injector system, as we mentioned before, is a system for direct diesel injection. This system is also known as the pump - nozzle system. Bosch first introduced this system in 1994 for UIS commercial vehicles. The most important feature of this system which differs from other systems is that the injection nozzle and injection pump are turned into a single unit. This system has a maximum of 8 cylinders. These cylinders are equipped with 80kW performance. It is generally preferred in commercial vehicles of this size.
Unit Pump Injector Spare Parts;
Unit pump injector systems have some spare parts. We will list these spare parts to help you:
-Pump piston
-Injector nozzle needle
-Pump piston return spring
-Injector nozzle spring
- Solenoid valve pin
- Sealing piston
-Injector pump valve
-High pressure chamber
The amount of injection within this system determines the operation of the solenoid valve. It serves as fuel injection to the combustion chamber as long as it is closed.
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