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An electronically controlled, microprocessor equipped fuel injection system for new manufacture or retrofit of existing diesel engines has a tubular injector provided with a fuel pressure amplification chamber next adjacent and communicating directly with an injector nozzle at one end of the tube; t

An electronically controlled, microprocessor equipped fuel injection system for new manufacture or retrofit of existing diesel engines has a tubular injector provided with a fuel pressure amplification chamber next adjacent and communicating directly with an injector nozzle at one end of the tube; the nozzle has atomizing orifices for spraying the pressure amplified fuel into the engine cylinder. A fuel flow controlling solenoid is provided at the opposite end of the tube and all component parts in the tube between the nozzle and a spring loaded solenoid armature are disposed along a common axis extending longitudinally of the tube. Such parts include a fuel pressure amplification plunger, a hydraulic pumping piston for actuating the plunger, a spool valve shiftable toward and away from the armature and a needle valve normally closing the orifices. Three fuel pressures exist in the injector from time to time, namely medium inlet fuel pressure supplied by the engine fuel pump, low pressure return fuel to the supply tank and highly intensified fuel pressure produced in the nozzle upon energization of the solenoid to insure injection of controlled amounts of fuel into a respective cylinder of the engine notwithstanding the pressure conditions existing in a corresponding cylinder during fuel injection.

대표청구항 ▼

1. In a fuel injector, a tubular body having a fuel inlet port for receiving a constant supply of pressurized fuel and a fuel exhaust port, each disposed intermediate the ends of the body; a fuel injection nozzle secured to the body at one of said ends and having fuel atomizing orifice means; v

1. In a fuel injector, a tubular body having a fuel inlet port for receiving a constant supply of pressurized fuel and a fuel exhaust port, each disposed intermediate the ends of the body; a fuel injection nozzle secured to the body at one of said ends and having fuel atomizing orifice means; valve means reciprocable in the body along the longitudinal axis of the body toward and away from the orifice means and normally closing the latter; means presenting a fuel pressure amplification chamber in the body adjacent the nozzle and communicating directly therewith; a fuel pressure amplifying plunger extending from the chamber toward the opposite of said ends and reciprocable in the body along said axis toward and away from the orifice means; blocking means normally precluding flow of fuel from the inlet port to the exhaust port; selectively operable power means associated with said body, said blocking means being releasable upon actuation of the power means; and structure in the body operable upon said actuation of the power means for forcing the valve away from the orifice means to open the latter and forcing the plunger toward the orifice means in response to the pressure of fuel in the body whereby to amplify the fuel pressure in the chamber and to spray the pressure amplified, atomized fuel emanating from the orifice means into a cylinder of an internal compression ignition engine, said chamber being located next adjacent the orifice means in the nozzle to cause fuel to be injected into the cylinder of said engine through the orifice means upon actuation of the power means without significant time delay following actuation of said power means and consequential unblocking of the orifice means. 2. The invention of claim 1, the nozzle having a shell releasably attached thereto and containing a tip provided with a discharge port adapted for closing of the valve, the orifice means being a series of discharge grooves in the tip communicating with the port of the tip, the shell and the tip being of wear resistant material. 3. The invention of claim 1; and buffer means for maintaining the fuel supply at a predetermined pressure level in the inlet port. 4. The invention of claim 1; there being a fuel supply line for the inlet port and a fuel return line for the exhaust port, there being buffer means in each said lines. 5. The invention of claim 1, said fuel pressure amplifying plunger being operable to increase the pressure of the fuel in said chamber from about 8 to about 10 times the inlet fuel pressure to said body. 6. The invention of claim 1, said power means being a single solenoid carried by the body at said opposite end, said solenoid having an armature spaced away from the plunger and reciprocable toward and away from the latter along an axis aligned with said axis of the body, the blocking means being releasable upon energization of the solenoid to retract the armature. 7. The invention of claim 6, said structure including means responsive to the amplified pressure of fuel in the chamber for blocking the flow of the amplified fuel from the chamber to the inlet port. 8. The invention of claim 7, said solenoid having resilient means yieldably biasing the armature away from the plunger. 9. The invention of claim 8, said structure including resilient means in the body yieldably biasing the valve means toward the orifice means. 10. The invention of claim 9, said structure including a plunger-engaging piston reciprocable in the body along said axis of the latter toward and away from the orifice means for forcing the plunger toward the orifice means in response to the pressure of fuel in the body when the solenoid is energized. 11. In a fuel injector, a tubular body having a fuel inlet port for receiving a constant supply of pressurized fuel and a fuel exhaust port, each disposed intermediate the ends of the body; a fuel injection nozzle secured to the body at one of said ends and having fuel atomizing orifice means; valve means reciprocable in the body along the longitudinal axis of the body toward and away from the orifice means and normally closing the latter; means presenting a fuel pressure amplification chamber in the body adjacent the nozzle and communicating directly therewith; a fuel pressure amplifying plunger extending from the chamber toward the opposite of said ends and reciprocable in the body along said axis toward and away from the orifice means; blocking means normally precluding flow of fuel from the inlet port to the exhaust port; selectively operable power means associated with said body, said blocking means being releasable upon actuation of the power means; and structure in the body operable upon said actuation of the power means for forcing the valve away from the orifice means to open the latter and forcing the plunger toward the orifice means in response to the pressure of fuel in the body whereby to amplify the fuel pressure in the chamber and to spray the pressure amplified, atomized fuel emanating from the orifice means into a cylinder of an internal compression ignition engine, said power means being a single solenoid carried by the body at said opposite end, said solenoid having an armature spaced from the plunger and reciprocable toward and away from the latter along an axis aligned with said axis of the body, the blocking means being releasable upon energization of the solenoid to retract the armature, said structure including means responsive to the amplified pressure of fuel in the chamber for blocking the flow of the amplified fuel from the chamber to the inlet port, said solenoid having resilient means yieldably biasing the armature away from the plunger, said structure including resilient means in the body yieldably biasing the valve means toward the orifice means, said structure including a plunger-engaging piston reciprocable in the body along said axis of the latter toward and away from the orifice means for forcing the plunger toward the orifice means in response to the pressure of fuel in the body when the solenoid is energized, said structure including a tube rigid in the body and exxtending into the plunger at that end of the latter remote from the chamber along said axis of the body, said piston and said plunger being reciprocable along the tube. 12. The invention of claim 11, said structure including fuel flow controlling valving reciprocable in the body between the plunger and the blocking means along said axis of the body. 13. The invention of claim 12, said structure including a disk rigid in the body between the armature and the valving, said disk having a perforation surrounding said axis of the body, said blocking means including a perforation-closing element carried by the armature for reciprocation therewith. 14. The invention of claim 13, said valving being normally spaced from the disk and normally blocking the flow of fuel from the tube to the piston. 15. The invention of claim 14, said means for biasing the valve means including a coil spring in the plunger between the tube and the valve means. 16. The invention of claim 15, said valving having a conduit extending along said axis for flow of fluid between the tube and the disk. 17. The invention of claim 16; and a follower for the resilient means reciprocable in the plunger along said axis of the body and engaging the valve means, said resilient means abutting the follower. 18. The invention of claim 17, said valve means having a stem engaging the follower and reciprocable in the plunger along said axis of the body. 19. The invention of claim 18; and stop means in the body for limiting the extent of movement of the valve means away from the orifice means, said stem having a shoulder engageable with the stop means. 20. The invention of claim 19; and a pair of spaced movement limiting means in the body for controlling the extent of reciprocation of the piston. 21. The invention of claim 14, said structure having means for cushioning the movement of the piston against one of said limiting means when the piston moves toward the orifice means.