Based On Torque Control Of High-pressure Common Rail Diesel Engine Fuel Injection System

High-pressured common rail diesel engine fuel injection system is able to realize the comprehensive flexible control of the fuel quantity, the injection pressure and the injection rules, so that achieves the effect of the soft combustion, efficiently reduces combustion noise and exhaust gas emission. It is a milestone on the way of the diesel development. According to the engine operating condition and considering the outside real-time corrected condition, the realization of the ideal injection rule should be the research focal point of high-pressured common rail system control strategy.The high-pressured common rail diesel engine fuel injection system's control strategy has been integrate and systemically established:Based on the engine indicated torque, through torque/quantity conversation and injection coordination, the injection parameters have been calculated (fuel quantity, start of energizing, the energizing time for injections). ETAS Corporation's ECU development tools have been applied and the control model has been established. By the method of software off-line simulation, the torque/quantity conversation and the injection process have been tested.The demand torque of vehicles accessories has been synthetically evaluated. Taking the engine exterior demand torque as the input variable, satisfying the engine minimum drag torque, and considering engine system performance limitation and engine protection, etc., the control strategy of the setpoint path and lead path torque has been formulated, and the engine indicated torque has been calculated. Having been conversed torque/quantity, the injection setpoint quantity has been acquired. According to the engine operating condition and considering the outside corrected condition the injection characteristic has been obtained. It means the number and type of injections has been determined for every cinder in each circle, and fuel quantity, start of energizing, the energizing time for injections and injection release have been calculated. The multi-injection mode of'Pilot injection+Main injection+Post injection' has been applied. However, whether the pilot injection and post injection can be activated is depended on the release condition. This research on the control strategy of high-pressured common rail diesel engine fuel injection system provides the issue technical support for the establishment of entire high-pressured common rail system.