HIGH-PRESSURE ELECTROMAGNETIC FUEL INJECTOR

摘要

A high-pressure electromagnetic fuel injector (10) having a dual-function valve (44) directly controlled by an electric solenoid (34). Fuel pressure in a control volume chamber (20) is controlled by the dual-function valve (44), and a separate control valve (46) is controlled as a function of fuel pressure in the control volume chamber (20). A spray tip valve (50) is, in turn, controlled as a function of the pressure of fuel controlled by the control valve to inject fuel through a spray tip orifice (32). The dual-function valve (44) spills fuel during and after the control valve (46) closes, thus reducing the amount of uncontrolled fuel at the end of an injection. The dual-function valve (44) also provides a drain path through which to vent any fuel that leaks past the control valve.