Diesel Engines Fuel Pressure Is Controlled Mechanically And Depending On The Camshaft

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In the past, in diesel engine fuel pressure was controlled mechanically and depending on the camshaft. Due to this geography lots of problems occurs like engine emission, engine torque, engine efficiency etc. To overcome these problem or for the better performance caterpillar invented new technology called Hydraulically actuated Electronic Unit Injection (HEUI) fuel systems.
1.1 Introduction:
To achieving outstanding fuel economy, high torque output and to reduce the emission produced from the relatively small engine displacement an innovative injection technology has came in the early 1990’s. The use of hydraulic force to pressurize fuel for injection was innovative technology to advance the use of powerful, cleaner and …show more content…

Since the functions of metering, increase of pressure, timing and atomization are all combined into the injector. These especially designed injectors are supplied not only with fuel but highly pressurized lube oil. An engine driven high pressure oil pump supplies fuel to the injectors at pressures close to 4,000 psi. Within the injector, hydraulic force is further amplified to give HEUI’s the capability to achieve injection pressures of up to 28,500 psi from the latest injectors. Since oil can be pressurized to very high pressures independently of engine speed, high injection pressure is achievable at low engine RPM. The high pressure injection capabilities joint with electronic control of timing and injection rate ensures the best atomization of fuel, low emissions, higher performance and fuel economy. This pressure is available at almost any engine speed and load condition which permits the HEUI system to perform in any diesel engine application by simply changing software programming. This feature by definition tells the difference the HEUI system as a type of common rail fuel system. In sequence developments in HEUI technology have allowed for improved ability to shape the rate of fuel injection which further reduces combustion noise and emissions for quieter cleaner engine operation. HEUI injectors are easily replaced by technicians with almost no adjustment or special engine

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