This paper presents a new series of Timing and Injection Rate Control Systems: AD-TICS and P-TICS, for medium and heavy duty DI diesel engines. These TIC systems are equipped with a new concept of variable pumping rate, which is realized by controlling the prestrokes of the pumping elements.
First, the outline of these new injection systems will be briefly described, showing the basic constructions and the range of applications, with some diagrams and schemata.
Secondly, the injection characteristics of the jerk injection system will be clarified by simulation calculations, comparing the pump-pipe-nozzle with the unit injector. Calculation results will enable a comprehensive interpretation of the behavior of such injection characteristics as injection pressure, duration, etc., ie, in accordance with the pumping rate, dead volume, and nozzle orifice area, etc..
Furthermore, detailed characteristics obtained using AD-TICS and P-TICS will be shown. Major discussion points are:
Injection pressure level attained
Injection rate pattern
Relation between injection timing, injection rate, and spray penetration
Dynamic characteristics of timing and metering