160MPa COMMON-RAIL DIESEL FUEL INJECTOR CONTROLLED BY A TANDEM ARRAYED GIANT-MAGNETOSTRICTIVE ACTUATOR

A quick response injector has a potential to improve exhaust gas emissions. This paper describes performance of a newly designed pilot operated proportional injector for a common-rail diesel fuel injection system. The main needle valve is positioned by a hydro-mechanical servomechanism with feedback slot for continuous flow-rate control, and the pilot valve is operated by a tandem arrayed giant-magnetostrictive actuator for linear motion control. The injector discharges flow-rates up to 30 mm3/ms linearly to electric current at 160MPa pressure within on/off lag time of 0.35ms (on) and 0.5ms (off) by using a nozzle of 6 holes x 0.16mm in diameter.