The pump-pipe-injector-injection system is the most commonly used type of injection equipment for Diesel engines. In order to be compatible with digital engine control, this system needs to be modified. The resulting fuel injection system should have the following characteristics: mechanical simplicity, direct control capability and low cost.
Based on these requirements, the direct digital control of the pump-pipe-injector injection system has been investigated. A new solenoid control valve has been designed to simultaneously control the injection timing, fuel quantity and hydraulic performance. The conventional jerk-pump is very much simplified. A research type control unit based on a PC has been developed. The system has the possible configuration of electronic pump-pipe-valve-injector and electronic pump-valve-pipe-injector.
The system was designed and analyzed on the basis of a comprehensive mechanical - magnetic - electrical - hydraulic computer simulation of the system. A new type of drive circuit and computer interface as well as control software are presented.
The preliminary test results on the electronic pump-pipe-valve-injector system in a special experimental set-up and in a research diesel engine are reported.