초록 ▼

An improved fuel injector (10) having a needle valve (31) is mounted within a separate removable guide (26) for sliding movement between seated and unseated positions on a valve seat (18). Fuel injector (10) is adapted for operation in a primary fluid control mode (FIG. 5) under the influence of pre

An improved fuel injector (10) having a needle valve (31) is mounted within a separate removable guide (26) for sliding movement between seated and unseated positions on a valve seat (18). Fuel injector (10) is adapted for operation in a primary fluid control mode (FIG. 5) under the influence of pressurized control fluid in a fluid chamber (30) adjacent the outer end of the needle valve (31), and for alternate operation in a secondary mechanical control mode (FIG. 6) under a mechanical mode spring (96) in the event of a decrease in operating fluid control pressure of the pressurized control fluid below a predetermined minimal amount. Continuous operation of the fuel injector (10) in the alternate operation under the mechanical spring (96) mode is automatic upon the reaching of a predetermined minimum pressure in the operating control fluid. A shutdown system is illustrated in FIG. 7 which overrides both the primary fluid control mode of operation and the secondary mechanical spring mode of operation to hold the needle valve (31) in seated position on its seat ( 18) under a fluid control pressure when certain engine conditions outside safe operating ranges are sensed. A microprocessor (98) receives input signals from sensors (98A-98H) for sensing various predetermined operating parameters of the engine and provides an output signal to a pressure regulator for controlling the pressure in the control fluid in response to the sensors (98A-98H).

대표청구항 ▼

An improved fuel injector adapted for use with a fuel injection system for a multi-cylinder internal combustion engine including a control fluid pressure source and a pressurized fuel source; said fuel injector comprising: an elongate body having a bore therein; a fuel nozzle at an inner end of said

An improved fuel injector adapted for use with a fuel injection system for a multi-cylinder internal combustion engine including a control fluid pressure source and a pressurized fuel source; said fuel injector comprising: an elongate body having a bore therein; a fuel nozzle at an inner end of said body for projecting within an associated cylinder combustion chamber for delivery of fuel therein, a fuel chamber adjacent the fuel nozzle and having pressurized fuel therein, and a valve seat between the fuel nozzle and fuel chamber; a valve mounted within said bore on said valve seat and movable between open and closed positions relative to said valve seat and said nozzle, said valve being in communication with pressurized fuel in said fuel chamber and urged toward an open unseated position by said pressurized fuel for providing fuel to said nozzle for discharge into an associated cylinder; a pressurized control fluid chamber in said body adjacent said valve and having pressurized control fluid therein for urging said valve toward a closed seated position on said valve seat to block the flow of fuel to said nozzle under a primary fluid control mode of operation; a mechanical mode spring in said body operable upon the decrease in pressure of said control fluid below a predetermined minimum amount for urging said valve toward a seated closed position on said valve seat, said mechanical mode spring comprising a compression spring acting against the outer end of said valve for urging said valve toward a seated position; and means to maintain said mechanical mode spring in an inoperable position during the primary fluid control mode of operation; said bore of said body including a guideway in which said valve is mounted for longitudinal movement between seated and unseated positions relative to said valve seat, said control fluid chamber being positioned adjacent the outer end of said guideway with pressurized control fluid therein providing a fluid seal between said valve and said guideway, and cushioning the movement of said valve to an unseated open position.