Ultrasonic unitized fuel injector with ceramic valve body

• US 6,543,700 B2
• Filed: 07/26/2001
• Issued: 04/08/2003
• Est. Priority Date: 12/11/2000
• Status: Expired due to Term

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Gipson, Lamar Heath, Cohen, Bernard, Jameson, Lee Kirby
• Primary Examiner(s): EVANS, ROBIN OCTAVIA
• Application Number:
  US09/915,633
• Publication Number:
  US 20020070287A1
• Time in Patent Office: 621 Days
• Field of Search: 239/88, 239/89, 239/90, 239/91, 239/92, 239/93, 239/94, 239/95, 239/96, 239/585.1, 239/585.2, 239/585.3, 239/585.4, 239/585.5, 239/102.1, 239/102.2
• US Class Current: 239/102.1
• CPC Class Codes: F02M 57/023 mechanical
• CPC Class Codes: F02M 61/166 Selection of particular materials
• CPC Class Codes: F02M 69/041 having vibrating means for atomizing the fuel, e.g. with sonic or ultrasonic vibrations

Abstract

An ultrasonic fuel injector for injecting a pressurized liquid fuel into the combustion chamber of an internal combustion engine that uses an overhead cam for actuating the injector includes a valve body having an injector needle disposed therein forming a needle valve to meter the flow of fuel through the injector. The valve body is formed of ceramic material that is transparent to magnetic fields changing at ultrasonic frequencies. The injector needle includes a magnetostrictive portion disposed in the region of the valve body that is surrounded by a wire coil wound around the outside surface of the ceramic valve body. The wire coil is connected to a source of electric power that oscillates at ultrasonic frequencies. A sensor is configured to signal when the overhead cam is actuating the injector to inject fuel into the combustion chamber of the engine. The sensor is connected to a control that is connected to the power source and is configured to operate same only when the overhead cam is actuating the injector to inject fuel into the combustion chamber of the engine. When the power source activates the oscillating magnetic field in the coil and applies same to the magnetostrictive portion of the needle, ultrasonic energy is applied to the pressurized liquid. The method involves retrofitting a conventional injector with a needle having a magnetostrictive portion and with a ceramic valve body surrounded by wound wire coils configured and disposed to subject the magnetostrictive portion of the needle to ultrasonically oscillating magnetic fields.

Claims

1. An ultrasonic, unitized fuel injector apparatus for injection of pressurized liquid fuel into an internal combustion engine that actuates the injector by at least one overhead cam contacting a cam follower, the apparatus comprising:

a valve body formed of ceramic material that is transparent to magnetic fields changing at ultrasonic frequencies, said valve body defining;

a cavity configured to receive therein at least a first portion of an injector needle,

a discharge plenum communicating with said cavity and configured for receiving pressurized liquid fuel and at least a second portion of said injector needle,

a fuel pathway communicating with said discharge plenum and configured to supply the pressurized liquid fuel to said discharge plenum, and

an exit orifice communicating with said discharge plenum and configured to receive the pressurized liquid fuel from said discharge plenum and pass the liquid fuel out of said valve body;

a means for applying within said cavity a magnetic field changing at ultrasonic frequencies, said means being carried at least in part by said valve body;

an injector needle having a first portion disposed in said cavity and a second portion disposed in said discharge plenum, said first portion of said injector needle being formed of magnetostrictive material responsive to magnetic fields changing at ultrasonic frequencies;

a sensor configured to signal when the injector is injecting pressurized liquid fuel into the internal combustion engine; and

a control connected to said sensor and to said means for applying within said cavity a magnetic field changing at ultrasonic frequencies, said control being configured to activate said means for applying within said cavity a magnetic field changing at ultrasonic frequencies when said sensor signals that the injector is injecting fuel into the combustion chamber of the engine.

2. The apparatus of claim 1, further comprising:

an injector nut surrounding said valve body, wherein said valve body defines a dome portion configured to be received in said injector nut; and

an annular collar disposed between said dome portion of said valve body and said injector nut and configured to bear the compressive load applied to said valve body within said injector nut.

3. The apparatus of claim 2, wherein said means for applying within said cavity a magnetic field changing at ultrasonic frequencies includes an electrically conducting coil disposed around said cavity.

4. The apparatus of claim 2, wherein said annular collar is composed of metal.

5. The apparatus of claim 4, wherein said annular collar is defined by a circular annular member.

6. The apparatus of claim 5, wherein said annular collar is composed of aluminum.

7. The apparatus of claim 6, wherein said means for applying within said cavity a magnetic field changing at ultrasonic frequencies includes an electrically conducting coil disposed around said cavity.

8. The apparatus of claim 3, wherein said valve body includes potting material embedding said electrically conducting coil therein.

9. The apparatus of claim 5, wherein said means for applying within said cavity a magnetic field changing at ultrasonic frequencies includes a power source and an electrically conducting coil disposed around said cavity.

10. The apparatus of claim 4, wherein said means for applying within said cavity a magnetic field changing at ultrasonic frequencies includes an electrically conducting coil disposed around said cavity, and said valve body includes potting material embedding said electrically conducting coil therein.

11. The apparatus of claim 1, wherein said means for applying within said cavity a magnetic field changing at ultrasonic frequencies is disposed at least in part within said valve body.

12. The apparatus of claim 1, wherein said sensor includes a piezoelectric transducer that is disposed to detect a predetermined magnitude of pressure from contact by at least one of the cams with a cam follower.

13. The apparatus of claim 1, wherein said means for applying within said cavity a magnetic field changing at ultrasonic frequencies includes an electrically conducting coil disposed around said cavity.

14. The apparatus of claim 1, further comprising a plurality of exit orifices, each said exit orifice being configured and disposed to communicate with said discharge plenum and to receive the pressurized liquid fuel from said discharge plenum and pass the liquid fuel out of said valve body.

15. The apparatus of claim 1, wherein the ultrasonic frequencies range from about 15 kHz to about 500 kHz.

16. The apparatus of claim 1, wherein the ultrasonic frequencies range from about 15 kHz to about 60 kHz.

17. An internal combustion engine, wherein said engine includes the apparatus of claim 1.

18. A vehicle, comprising:

the engine of claim 17.

19. An electric generator, comprising:

the engine of claim 17.

20. A method of retrofitting an ultrasonic, unitized fuel injector apparatus for injection of pressurized liquid fuel into an internal combustion engine that actuates the injector by at least one overhead cam, this injector including a needle valve that can be biased in the valve'"'"'s closed position as the valve seat is sealed against one end of the needle while the opposite end of the needle engages an overhead cam that actuates the opening and closing of the needle valve, and thus controls the supply of fuel through the exit orifices of the injector into the combustion chamber that is served by the injector, the method comprising:

removing the injector'"'"'s needle and substituting there for a needle that has an elongated portion that is composed of magnetostrictive material;

forming the injector'"'"'s valve body of ceramic material that is transparent to magnetic fields oscillating at ultrasonic frequencies;

surrounding the exterior of said ceramic valve body by a coil that is capable of inducing a magnetic field changing at a predetermined ultrasonic frequency in the region occupied by the magnetostrictive portion and thus causing the magnetostrictive portion to vibrate at ultrasonic frequencies; and

disposing on the injector a sensor that is configured to detect when at least one of the cams is actuating the injector to inject fuel into the combustion chamber of the engine.

21. The method of claim 20, further comprising the steps of:

electrically connecting said coil to an ultrasonic power source;

electrically connecting said sensor to a control that is electrically connected to said power source and that is configured to activate said power source only when said sensor signals that said one of the cams is actuating the injector to inject fuel into the combustion chamber of the engine.