Composite spark plug
View Patent ↗A composite ignition device includes a positive electrode having a tip formed thereon that is bonded to a first insulator to form a firing cone assembly. A second insulator having a negative capacitive element embedded therein is attached to the firing cone assembly. A positive capacitive element is disposed in the second insulator and is separated from the negative capacitive element by the second insulator. The positive capacitive element is coupled to the positive electrode. The positive and negative capacitive elements form a capacitor. A resistor is coupled to the positive capacitive element. An electrical connector is coupled to the resistor and attached to the second insulator. A shell including a negative electrode having a tip is attached to the second insulator and the firing core assembly and coupled to the negative capacitive element. The negative electrode tip is spaced apart from the positive electrode tip.
1. A composite ignition device for an internal combustion engine, comprising:
a positive electrode comprising a tip;
a coating of conductive ink bonded to said positive electrode;
a first insulator comprising a ceramic cone;
a spark gap comprising:
a J-shaped negative electrode comprising a tip;
said ceramic cone; and
a terminal end of said positive electrode tip positioned flush with an end of said ceramic cone and disposed a predetermined distance from said J-shaped negative electrode;
a second insulator;
a negative capacitive element;
a positive capacitive element separated from said negative capacitive element by said second insulator, said positive capacitive element coupled to said positive electrode, said positive capacitance element and said negative capacitive element forming a capacitor, said positive capacitive element is coupled to a boss of said positive electrode by an interference fit;
a resistor disposed in a resistor insulator and disposed above said positive capacitive element by a resistor connector, said resistor disposed in a position to reduce charging current of said capacitor;
said resistor connector coupled to said positive capacitive element;
said ceramic cone having a concentric cavity formed therein;
said tip of said J-shaped negative electrode comprising an erosion reducing bonding agent;
said first insulator comprising a concentric locking detent, a portion of said second insulator disposed in said detent thus locking said first and said second insulators together; and
a shell, said shell including said J-shaped negative electrode, wherein the negative capacitive element comprises at least one flange extending radially therefrom, wherein the at least one flange comprises at least one scallop to ensure a complete flow of the second insulator around the negative capacitive element.
2. The device of claim 1 wherein said negative capacitive element is embedded in said second insulator.
3. The device of claim 2 wherein said negative capacitive element is embedded in said second insulator by a manner selected from the group consisting of injection molding and insert molding.
4. The device of claim 1 wherein said second insulator comprises an engineered polymer.
5. The device of claim 4 wherein said engineered polymer comprises liquid crystal polymer.
6. The device of claim 4 wherein said engineered polymer comprises polyetheretherketone.
7. The device of claim 4 wherein said engineered polymer has a dielectric constant from between about 5 to about 10.
8. The device of claim 7 wherein said alumina material comprises from about 88 percent to about 99 percent pure alumina.
9. The device of claim 1 wherein said first insulator comprises an alumina material.
10. The device of claim 1 wherein said resistor connector comprises a spring member.
11. The device of claim 1 wherein said positive and negative electrodes comprise a sintered rhenium and tungsten material.
12. The device of claim 11 wherein said material comprises about equal parts rhenium and tungsten.
13. The device of claim 11 wherein said material comprises about three times as much rhenium as tungsten.
14. The device of claim 1 wherein said conductive ink comprises a precious metal or precious metal alloy.
15. The device of claim 1 wherein said capacitor has a predetermined capacitance in the range from about 30 to about 100 pF.
16. A circuit for an ignition device for an internal combustion engine, comprising:
a power source operable to intermittently activate said circuit;
a positive electrode comprising a tip;
a metal shell, connected to a J-shaped ground electrode;
a first insulator separating said positive electrode from said metal shell;
at least one resistor connected in series with said power source and said positive electrode;
a spark gap comprising:
a said J-shaped ground electrode, said J-shaped ground electrode comprising a tip;
a ceramic cone formed from an end of said first insulator; and
a terminal end of said positive electrode tip positioned flush with an end of said ceramic cone and disposed a predetermined distance from said J-shaped ground electrode;
said tips of said J-shaped negative electrode and said positive electrode comprising an erosion reducing bonding agent; and
at least one capacitor directly connected to said resistor and connected in parallel with said positive electrode and ground, said resistor not in parallel with said capacitor; said capacitor comprising a second insulator which forms a dielectric of said capacitor, said first and second insulators locked together via a detent formed on one of said insulators; and
said resistor coupled to said positive electrode by a resistor connector, wherein said capacitor comprises a negative capacitive element and a positive capacitive element separated from said negative capacitive element by said second insulator, wherein the positive capacitive element is inside the negative capacitive element, wherein the negative capacitive element comprises at least one flange extending radially therefrom, wherein the at least one flange comprises at least one scallop to ensure a complete flow of the second insulator around the negative capacitive element.
17. The circuit of claim 16 wherein said at least one resistor reduces radio frequency interference (RFI) when said circuit is active.
18. The circuit of claim 16 wherein said at least one capacitor increases peak current to said spark gap when said circuit is active.
19. The circuit of claim 16 wherein at least one of said tips comprises a sintered rhenium and tungsten material.
20. The circuit of claim 19 wherein at least one of said tips comprises about equal parts of rhenium and tungsten.
21. The circuit of claim 19 wherein at least one of said tips comprises about three times as much rhenium as tungsten.
22. The circuit of claim 16 wherein said at least one resistor has a predetermined total resistance in the range from about 2 kohms to about 20 kohms.
23. The circuit of claim 16 wherein said at least one capacitor has a predetermined total capacitance in the range from about 30 to about 100 pF.
24. A composite ignition device for an internal combustion engine, comprising:
a positive electrode formed from a first electrode material having a tip formed on an end thereof, said tip formed from a material different from said first electrode material;
a boss formed on said positive electrode;
a capacitive element, said capacitive element formed from a first conductive material, a second conductive material, and an insulator disposed there between; said first conductive material coupled to said positive electrode;
a ceramic cone having a concentric cavity formed therein, said boss nestled within said cavity and a stud of said positive electrode extending beyond said ceramic cone;
said insulator and said ceramic cone locked together via a detent configuration;
a gas seal comprising a glass frit material disposed in said concentric cavity of said ceramic cone, holding said boss therein;
a spark gap comprising:
a J-shaped negative electrode comprising a tip;
said ceramic cone;
a terminal end of said tip of said positive electrode positioned flush with an end of said ceramic cone and disposed a predetermined distance from said J-shaped negative electrode; and
said tips of said J-shaped negative electrode and said positive electrode comprising an erosion reducing bonding agent; and
a resistor coupled to said first conductive material by a resistor connector without said resistor reducing current from said capacitor to a spark gap of said ignition device, said resistor disposed in a position to reduce charging current of said capacitor, wherein the first conductive material is inside the second conductive material, wherein the second conductive material comprises at least one flange extending radially therefrom, wherein the at least one flange comprises at least one scallop to ensure a complete flow of the insulator around the second conductive material.
25. A composite ignition device for an internal combustion engine, comprising:
a positive electrode formed from a first electrode material having a tip formed on an end thereof, said tip formed from a material different from said first electrode material;
a boss formed on said positive electrode;
a capacitive element, said capacitive element formed from a first conductive material, a second conductive material, and an insulator disposed there between; said first conductive material coupled to said positive electrode;
a ceramic cone having a concentric cavity formed therein, said boss nestled within said cavity and a stud of said positive electrode extending beyond said ceramic cone;
said insulator and said ceramic cone locked together via a detent configuration;
a spark gap comprising:
a J-shaped ground electrode comprising a tip formed thereon;
said ceramic cone; and
a terminal end of said tip of said positive electrode positioned flush with an end of said ceramic cone and disposed a predetermined distance from said J-shaped ground electrode;
said tips of said J-shaped negative electrode and said positive electrode comprising an erosion reducing bonding agent;
a resistor coupled to said first conductive material by a resistor connector without said resistor reducing current from said capacitor to a spark gap of said ignition device, said resistor disposed in a position to reduce charging current of said capacitor; and
said resistor connector comprising a spring member, wherein the first conductive material is inside the second conductive material, wherein the second conductive material comprises at least one flange extending radially therefrom, wherein the at least one flange comprises at least one scallop to ensure a complete flow of the insulator around the second conductive material.