Claims
- 1. In a high power high energy ignition system for internal combustion engines including at least one energy storage and discharge capacitor C, at least one resonating inductor of inductance Le, one or more ignition coils Ti of primary turns Np, secondary turns Ns, and turns ratio N, where i=1, 2, 3 , . . . , and each coil Ti having a coil primary current switch means Si, and each coil having its high voltage secondary winding connected to a spark plug, the system constructed and arranged according to the transient voltage doubling formulation with doubling factor DF equal to [(N**2)*C2/C], where C2 is the coil output capacitance, and magnetic flux formulations derived from Maxwell's equations to produce very high power high energy high efficiency ignition powered by an electrical power source for supplying power to the ignition system by charging up said capacitor C, the ignition firing controlled by an ignition controller to produce ignition sparks by discharging said capacitor C through actuation of said switch means Si, the improvement wherein said system is constructed and arranged:
- a) to provide, under normal operating conditions of the engine, ignition spark energy characterized by higher spark frequency and spark power during the early part of the sparking phase or spark duration to enable reduced size of the ignition coils Ti and to provide energy which changes slowly relative to engine speed, and
- b) to provide overall system optimization: (i) with doubling factor DF less than 0.4, and (ii) with coil core saturation flux density at normal operating temperatures to correspond approximately to the open circuit peak magnetic flux density B2[x(t0)] whose open circuit phase angle x(t0) is approximately 155 degrees at the peak of the secondary high voltage V2(0).
- 2. An ignition system as defined in claim 1 including a high frequency auxiliary circuit comprised of a series combination of a capacitor C11 of about half the capacitance of capacitor C, an inductor Le1 of about half the inductance Le, and a switch SS1 with one connection to ground, said series combination being in parallel with a series combination of capacitor C and inductor Le, such that on an ignition firing event switch SS1 is turned on to produce for the initial stage of a spark firing event an initial higher frequency breakdown spark of higher frequency than that of the main discharge circuit produced by discharging of capacitor C through inductor Le.
- 3. An ignition system as defined in claim 2 wherein said switch means Si comprises a first silicon control rectifier, SCR, switch with its cathode connected to ground and a return current switch SD connected across said first switch, return switch SD comprised of a series combination of SCR and diode, and wherein said switch means SS1 comprises a parallel combination of an insulated gate bipolar transistor, IGBT, and diode means, constructed and arranged to be triggered simultaneously with triggering of one or more coils Ti producing the initial high voltage breakdown field to produce an initial breakdown spark in a spark ignition device connected across the secondary winding of each coil Ti.
- 4. An ignition system as defined in claim 3 wherein one resonating inductor Le is used with more than one coil Ti with respective switch Si in series with primary winding of each coil Ti, said coils cascaded in parallel with each other with one end of their primary windings sharing a common rail point or section, the system being usable to sequentially fire said spark ignition devices when each switch Si is triggered sequentially.
- 5. An ignition system as defined in claim 1 further comprising high current switch control means SS constructed and arranged to controllably short out part or all of inductor Le during an early part of the firing of said ignition system.
- 6. An ignition system as defined in claim 1 wherein said ignition controller provides multiple spark pulses per ignition firing which are time modulated such that the spark pulsing frequency is higher at the early part of the spark firing.
- 7. An ignition system as defined in claim 6 wherein said spark pulses are speed modulated so that the spark pulsing frequency is higher at higher engine speeds.
- 8. An ignition system as defined in claim 1 wherein said ignition controller provides multiple spark pulses per ignition firing which are speed modulated such that the spark pulsing frequency is higher at higher engine speeds.
- 9. An ignition system as defined in claim 8 wherein the spark firing train changes from high frequency spark pulses to continuously firing spark oscillations at a high end portion of the said high engine speed range.
- 10. An ignition system as defined in claim 1 wherein said spark plug comprises an insulator end and firing end comprising an essentially toroidal firing zone with a shell end, a center conductor to whose bottom end is attached a firing end tip of erosion-resistant material which forms a circular toroidal spark gap of width of about 0.1" with the end of the spark plug shell and wherein the tip is extended radially and axially away from the insulator end section surrounding the center conductor to produce sparking away from the insulator end to minimize deposits on the insulator to reduce spark plug fouling.
- 11. An ignition system as defined in claim 10 wherein said spark gap width 11 is smaller than the radial dimension 12 between the end of the insulator end and the inner surface of the spark plug shell.
- 12. An ignition system as defined in claim 10 wherein the circular spark gap is at an angle of approximately 45 degrees with the vertical line defined by the length dimension of said center conductor.
- 13. An ignition system as defined in claim 10 wherein said tip includes a vertical metallic portion which together with said radial tip portion form a rail on which the spark can move without impinging on said insulator end section.
- 14. An ignition system defined in claim 13 wherein said vertical metallic portion extends from the firing end towards the insulator end up and beyond the plane defined by the shell end.
- 15. An ignition system as defined in claim 10 wherein said insulator end section is thin and of dimension of about 0.025" thickness.
- 16. An ignition system as defined in claim 10 wherein inner diameter of the shell end is approximately 0.4" or greater.
- 17. An ignition system as defined in claim 10 wherein said tip is partially circular to form a spark gap with one side of the plug shell so that the plug is capable of being appropriately indexed and oriented with respect to the air-flow vectors produced in an engine cylinder with its piston near top center and when so indexed and oriented and the plug is fired, the spark discharge moves outwards and away from the center of the spark plug to minimize plug fouling.
- 18. An ignition system as defined in claim 1 wherein said power source includes a boost power converter comprising an inductor Lb for storing magnetic energy Eb front a battery or other voltage source of voltage Vb and a switch SE for controlling the storage of said energy Eb and delivering it to a capacitive load at a higher voltage Vc.
- 19. An ignition system as defined in claim 18 including a power converter controller comprising controlled oscillator means for turning said switch SE on and off for durations Ton and Toff respectively, the oscillator including a timing capacitor Ct which is charged up to a high threshold and discharged through a discharge point to a low threshold to define the two periods Toff and Ton, capacitor Ct being charged through a resistor Rc connected at one end to said discharge point and to said capacitive load at voltage Vc to define the off-time Toff which decreases with increased voltage Vc, and timing capacitor Ct discharging through a resistor Rb connected between capacitor Ct and the discharge point to define the on-time Ton.
- 20. An ignition system as defined in claim 19 wherein a voltage limiting zener is connected to the discharge point with its anode to ground which provides over-voltage protection and a high battery voltage shut-off, and a zener is connected across resistor Rb for operation of the circuit and for providing a reduced Ton time with increased battery voltage Vb.
- 21. An ignition system as defined in claim 20 wherein said controlled oscillator is built on a 555 Timer device.
- 22. An ignition system as defined in claim 20 wherein said controlled oscillator comprises a comparator constructed and arranged to operate as an oscillator.
- 23. An ignition system as defined in claim 18 wherein said power converter is a boost converter and said switch comprises a main current carrying switch and a driver switch and wherein said inductor Lb and said main switch SE are connected in series with said high voltage side Vb of said battery with switch SE making a connection to the return side of the battery, and wherein said inductor has a tap for providing the driver switch with an additional drive voltage of about one volt above the voltage across said main switch, and wherein a connection is made from the intersection of the inductor and main switch SE to a load capacitor through an isolation means.
- 24. An ignition system as defined in claim 23 including a diode as a principal isolation component.
- 25. An ignition system as defined in claim 23 including a recharge circuit comprised of a recharge capacitor which is said load capacitor, a recharge inductor, and a diode with said recharge inductor isolated from said load capacitor by an isolation switch which is normally closed as long as the voltage on the load capacitor is above some value a fraction of the maximum value Vc.
- 26. An ignition system of claim 23 wherein said isolation means comprises a diode means in series with an isolation switch SI which is turned on for at least a portion of the time when the switch SE is turned off to allow energy stored on said inductor Lb to be delivered to said capacitor load.
- 27. An ignition system as defined in claim 1 wherein said power source includes an alternative boost power converter comprised of an inductor Lb for storing magnetic energy Eb from a battery or other voltage source of voltage Vb and a switch SEI for controlling the storage of said energy Eb and delivering it to a capacitive load at a higher voltage Vc and for providing isolation, wherein said power converter comprises series connection of said voltage source, said switch SEI, and said inductor whose one end is connected to the return side of voltage source, and the load capacitor is connected at the intersection of the switch SEI and the inductor.
- 28. An ignition system as defined in claim 27 wherein a diode is connected at the output side of load capacitor with its anode to ground to provide a complete path for power converter operation, and wherein said load capacitor is a recharge capacitor of a recharge circuit including a recharge inductor and a diode.
- 29. The ignition system defined in claim 27 including an inductor of inductance Lb' less than Lb located between the collector of main transistor switch SEI and the collector of driver transistor switch SES whose emitter is connected to the base of main switch SEI wherein said switches SEI and SES are PNP transistors.
- 30. The ignition system as defined in claim 29 wherein said drive transistor SES is controlled by an NPN control transistor whose emitter is grounded and whose collector is connected to the base of switch SES through a resistor.
- 31. An ignition system as defined in claim 29 wherein said inductor Lb is also part or all of the inductor of a recharge circuit and wherein said load capacitor C is a recharge capacitor of said ignition circuit.
- 32. A high power high energy ignition system including one or more spark plugs for producing ignition sparks wherein said spark plug comprises an insulator end and firing end comprising an essentially toroidal firing zone with a shell end, a center conductor to whose bottom end is attached a firing end tip of erosion-resistant material which forms a circular toroidal spark gap of width of about 0.1" with the end of the spark plug shell and wherein the tip is extended radially and axially away from the insulator end section surrounding the center conductor to produce sparking away from the insulator end to minimize deposits on the insulator to reduce spark plug fouling.
- 33. The ignition system as defined in claim 32 wherein tips defining said spark firing gap are plated with radioactive material.
- 34. A high power high energy ignition system including one or more spark plugs for producing ignition sparks wherein said spark plug comprises an insulator end and firing end comprising an essentially toroidal firing zone between a center conductor, an intermediate cylindrical conductor, and a shell end to form a concentric dual spark gap firing end with inner gap defined between said center conductor to whose bottom end is attached a firing end tip of erosion-resistant material which forms a circular toroidal spark gap with said intermediate cylindrical conductor end, and with outer gap defined between the tip of said cylindrical intermediate conductor of the spark plug shell end.
- 35. The ignition system as defined in claim 34 wherein tips defining said dual spark firing gap are plated with radioactive material.
- 36. The ignition system as defined in claim 34 wherein a high inductance spark plug wire is employed with said dual gap plug.
Parent Case Info
This application is a continuation-in-part of my patent application Ser. No. 8-066868, filed May 25, 1993.
US Referenced Citations (11)
Continuation in Parts (1)
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Number |
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66868 |
May 1993 |
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