Patent attributes
A very high speed injector permits injecting high pressure diesel oil directly into a diesel engine combustion chamber. The very high speed permits almost arbitrary rate shaping, minimizing formation of diesel particulate matter and oxides of nitrogen pollutants. An electrical waveform is pre-determined for a desired fuel injection rate shape. The electrical waveform is converted into a corresponding magnetic field waveform by a solenoid coil. A giant magnetostrictive material (GMM) transduces the magnetic field waveform into a corresponding mechanical waveform. The mechanical waveform positions a valve element to control flow rate. The very high speed features include a thin solenoid coil of relatively few turns, proportionally supplying up to one hundred amperes at up to one hundred volts in no greater than ten microseconds, the GMM is subject to a bias compressive stress magnitude of no less than fourteen megapascals, and the magnetic flux path is minimized and designed to suppress eddy currents.