Claims
- 1. A fuel injector for injecting fuel at high pressure into the combustion chamber of an engine, comprising:
an injector body containing an injector cavity and an injector orifice communicating with one end of said injector cavity to discharge fuel into the combustion chamber; a nozzle valve element positioned in one end of said injector cavity adjacent said injector orifice, said nozzle valve element movable between an open position in which fuel may flow through said injector orifice into the combustion chamber and a closed position in which fuel flow through said injector orifice is blocked; a control volume positioned to receive a pressurized supply of fuel; a drain circuit for draining fuel from said control volume to a low pressure drain; a valve seat positioned along said drain circuit; an injection control valve positioned along said drain circuit to control fuel flow from said control volume, said injection control valve including a reciprocally mounted control valve member movable between an open position permitting flow through said drain circuit and a closed position in sealing abutment against said valve seat to block flow through said drain circuit, said control valve member including an elongated portion extending from a position adjacent said valve seat toward an upstream portion of said drain circuit; and a guide surface formed on said injector body and positioned adjacent said elongated portion of said control valve member to permit relative sliding movement of said elongated portion while guiding said elongated portion.
- 2. The injector of claim 1, wherein said elongated portion extends axially along said fuel injector body toward said control volume, said guide surface being cylindrically shaped.
- 3. The injector of claim 2, wherein said elongated portion is cylindrically shaped.
- 4. The injector of claim 1, wherein said elongated portion extends to a position adjacent said control volume and forms at least a portion of an end wall forming said control volume.
- 5. The injector of claim 1, wherein a portion of said drain circuit is formed in said control valve member.
- 6. The injector of claim 5, wherein said portion of said drain circuit formed in said control valve member includes a central passage having a first end positioned in communication with said control volume.
- 7. The injector of claim 6, wherein said portion of said drain circuit further includes a transverse passage in communication with both a second end of said central passage and an annular cavity surrounding said control valve member.
- 8. The injector of claim 1, wherein said guide surface and said elongated portion form a partial fluid seal to minimize leakage while permitting smooth reciprocal movement of said control valve member.
- 9. The injector of claim 1, further including a nozzle valve element lift detecting means for detecting movement of said nozzle valve element into said open position and for providing a nozzle valve element lift feedback signal.
- 10. The injector of claim 9, wherein said nozzle valve element lift detecting means includes a piezoelectric element.
- 11. The injector of claim 1, wherein said injection control valve further includes a piezoelectric actuator connected to said control valve member.
- 12. The injector of claim 1, wherein said elongated portion of said control valve member includes a first section for engaging said valve seat and a second section formed separately from said first section, said second section containing a drain orifice for restricting drain flow.
- 13. The injector of claim 9, further including a control means for receiving said nozzle valve element lift feedback signal and generating an injection control signal based on said nozzle valve element lift feedback signal.
- 14. The injector of claim 13, wherein said control means varies said injection control signal based on said nozzle valve element lift feedback signal to vary at least one of a timing of an opening of said injection control valve and a rate of opening of said injection control valve.
- 15. The injector of claim 1, further including a stationary drain orifice formed in the injector body to drain fuel from the control volume.
- 16. The injector of claim 1, wherein said injector body includes a stationary section forming an end wall of the control volume, further including a drain orifice integrally formed in said stationary section.
- 17. A fuel injector for injecting fuel at high pressure into the combustion chamber of an engine, comprising:
an injector body containing an injector cavity and an injector orifice communicating with one end of said injector cavity to discharge fuel into the combustion chamber; a nozzle valve element positioned in one end of said injector cavity adjacent said injector orifice, said nozzle valve element movable between an open position in which fuel may flow through said injector orifice into the combustion chamber and a closed position in which fuel flow through said injector orifice is blocked; a control volume positioned to receive a pressurized supply of fuel; a drain circuit for draining fuel from said control volume to a low pressure drain; a valve seat positioned along said drain circuit a spaced distance from said control volume; and an injection control valve positioned along said drain circuit and including a reciprocally mounted control valve member movable toward an outer end of said nozzle valve element into an open position permitting flow through said drain circuit and away from said nozzle valve element into a closed position against said valve seat, said control valve member including an elongated portion extending from a position adjacent said valve seat to a position adjacent said control volume, said elongated portion including a distal end forming an end wall of said control volume.
- 18. The injector of claim 17, wherein a portion of said drain circuit is formed in said elongated portion, said drain circuit including a drain orifice.
- 19. The injector of claim 18, wherein said portion of said drain circuit formed in said elongated portion includes a central passage having a first end positioned in communication with said control volume.
- 20. The injector of claim 19, wherein said portion of said drain circuit further includes a transverse passage in communication with both a second end of said central passage and an annular cavity surrounding said control valve member.
- 21. The injector of claim 17, further including a guide surface formed on said injector body and positioned adjacent said elongated portion of said control valve member to permit relative sliding movement of said elongated portion while guiding said elongated portion, wherein said guide surface and said elongated portion form a partial fluid seal to minimize leakage while permitting smooth reciprocal movement of said control valve member.
- 22. The injector of claim 17, further including a nozzle valve element lift detecting means for detecting movement of said nozzle valve element into said open position and for providing a nozzle valve element lift feedback signal, further including a control means for receiving said nozzle valve element lift feedback signal and generating an injection control signal based on said nozzle valve element lift feedback signal.
Parent Case Info
[0001] This application is a continuation-in-part of application Ser. No. 10/011,462, filed Dec. 11, 2001.
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
10011462 |
Dec 2001 |
US |
Child |
10179017 |
Jun 2002 |
US |