Studies on Fundamental Characteristics - Comparison of Unit Injector and Pump-Line-Nozzle Injection Systems

We have investigated the fundamental characteristics of unit injectors and pump-line-nozzle systems theoretically by a graphical analysis of characteristic lines. We have confirmed the higher potential of unit injectors for higher injection pressure, compared with pump-line-nozzle systems. It can be said that the unit injector has the ability to reach higher injection pressures with smaller drive system and less power loss than that of pump-line-nozzle systems.

Furthermore, we have obtained basic views on how to improve the defective delivery characteristics in the low-speed region by a simulation method and with experiments. We have confirmed that modulus of rigidty in the driving system influences not only injection pressure but also injection mode.