Abstract
ABSTRACT
High specific power output diesel engines are used in armoured fighting vehicles and they are generally fitted with conventional fuel injection pumps. These pumps are usually with mechanical variable speed governors. Apart from its primary function of speed regulation they are required to perform a variety of tasks like fuel regulation depending upon turbo boost pressure, coolant temperature and engine shut off at low lubrication oil pressure. These are not easily achievable by conventional mechanical governors. Electronic governing systems coupled to mechanical conventional fuel injection pump (FIP) and using suitable software can easily meet the above requirements and yet be flexible to meet the demands of different applications. An electronic controller for 1000 HP, 12 cylinder V engine used for a armoured fighting vehicle. An electrical actuator was selected and fitted in the pump by replacing the mechanical governor. A robust speed-sensing device was developed and positioned on the pump. Suitable sensors for boost air pressure, coolant temperature and lubrication oil pressure were also located on the engine. Circuits for signal conditioning were developed. A program was developed in C for control of amount of fuel delivery based control rack regulation. The speed control module used a PID (proportional-Integral-derivative) controller. The entire system was tested on FIP bench by simulating the engine input parameters like boost air pressure, throttle position, coolant temperature and lubrication oil pressure. The system was integrated on the high power output diesel engine. Engine response on steady state and transient modes were recorded and studied. The development work resulted in the successful introduction of electronics in the conventional FIP to meet the requirements of add on features linked with fuel injection system.