INJECTION CONTROL VALVE OF AN ELECTRONICALLY CONTROLLED FUEL INJECTOR

摘要

An injection control valve of an electronically controlled fuel injector, comprising a control flat valve (8), an orifice plate (9), and a control piston sleeve (10). The lower end of the control flat valve (8) is provided with a sealing surface. The control piston sleeve (10) is provided below the orifice plate (9). An annular protrusion is provided on the upper end of the control piston sleeve (10). A control chamber (28), a return fuel orifice (24), and a orifice plate lower fuel opening (25) are provided on the orifice plate (9). An orifice plate fuel groove (36) is provided either on the lower end surface of the orifice plate (9) or on the upper end surface of the control piston sleeve (10). A control piston sleeve fuel opening (26) and a fuel inlet orifice (27) are provided on the control piston sleeve (10). The diameter of the fuel inlet orifice (27) is smaller than the diameter of the control piston sleeve fuel opening (26). The fuel inlet orifice (27) is in communication with the orifice plate fuel groove (36). A control piston (34) slides within the control piston sleeve (10). The upper end surface of the control piston (34) selectively blocks the lower end part of the orifice plate lower fuel opening (25). An inner annular groove (23), an outer annular groove (22), and a diversion groove (21) are provided on either the lower end surface of the control flat valve (8) or the upper end surface of the orifice plate (9). The outer annular groove (22) is provided outside of the inner annular groove (23). The outer annular groove (22) and the inner annular groove (23) are in communication via the diversion groove (21). The inner annular groove (23) is selectively in communication with the return fuel orifice (24). Employment of the injection control valve of the electrically controlled fuel injector reduces processing difficulty and increases tightness and productivity.