Hybrid ignition with stress-balanced coils
AssigneeIgnition Systems International, LLC.
InventorMichael A. V. Ward
Life of this patent
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Abstract
An improved high energy high efficiency hybrid capacitive/inductive ignition system with one or coils Ti for internal combustion engines employing one or more energy storage capacitor means (4) shunted by diode means (9), with high leakage inductor means (3a) of coils Ti with which have their primary (1a) and secondary (1b) windings wound side-by-side on a single segmented bobbin 72, unidirectional switches Si for each coil Ti which are preferably IGBTs, and high efficiency shunt diode/switch means SDi for each coil Ti shunting the primary winding of each coil Ti, so that, following production of an initial quarter cycle capacitive spark with peak current in the 0.2 to 3 amp arc discharge range, there is a decaying inductive unidirectional flow-resistant spark flowing through shunt switch means SDi.
Claims72
An ignition system for internal combustion engines comprising means defining an ignition circuit including at least one energy storage and discharge capacitor C, one or more ignition coils Ti of primary turns Np, secondary turns Ns, and turns ratio N=Ns/Np, where i=1, 2, 3, . . . , and each coil Ti having a coil primary current switch means Si in series with a primary winding of the coil Ti and with said capacitor means comprising a primary ignition discharge circuit which further includes a primary circuit inductance means comprised of a coil's primary leakage inductance Lpe and separate optional resonating inductance means Lej with inductance including zero inductance which with leakage inductance Lpe comprises the total primary circuit inductance Le, the system powered by an electrical power source for supplying power to the ignition system for charging said capacitor means C, and the ignition system operated and fired by an ignition firing means controlled by an ignition controller means to produce ignition sparks by discharging said capacitor means through actuation of said primary current switch means Si, the system constructed and arranged to produce, upon ignition firing through actuation of each said primary current switch means Si, an initial capacitive ignition spark discharge of a first quarter period oscillation defined by resonance oscillation of at least a porion of said capacitor means resonating with at least a portion of said total primary circuit inductance Le, followed by the inductive, essentially linear, decaying spark discharge of a longer period Tc whose peak amplitude corresponds to the peak amplitude of said first quarter period oscillation comprising an arc type spark discharge with an arc current greater than 0.2 amps and voltage doubling factor DF less than 0.4 where DF=N.sup.2 *Cs/C, and Cs is the total coil output capacitance.
A high energy hybrid capacitive/inductive ignition system with one or more coils Ti with E-cores with side-by-side primary and secondary windings with primary turns between 30 and 70 turns and primary leakage inductance Lpe between 100 uH and 600 uH and with energy storage capacitor means for storing and discharging ignition energy, each coil Ti using unidirectional switches Si and high efficiency shunt diode means SDi shunting the primary winding of its respective coil Ti, the ignition system producing an initial quarter cycle capacitive spark with a peak current in the arc discharge of at least 200 ma followed by a longer duration decaying inductive unidirectional spark discharge flowing through shunt switch means SDi, the system powered and controlled by a power converter and controller.
A high energy hybrid capacitive/inductive ignition system with one or more coils Ti and with energy storage capacitor means for storing and discharging ignition energy, each coil Ti using unidirectional switches Si which can be controllably turned off with high currents greater than 20 amps flowing through the switch, and high efficiency shunt diode means SDi shunting the primary winding of each respective coil Ti, the ignition system producing an initial quarter cycle capacitive spark with a peak current in the arc discharge of at least 200 ma followed by a longer duration decaying inductive unidirectional spark discharge flowing through shunt switch means SDi, the system powered and controlled by a power converter and controller.
An ignition coil for a capacitive discharge spark ignition system with side-by-side windings wherein the primary winding length lp is 1/5 to 1/3 of the core winding window length lw, and the ratio a/b is between 1 and 3, where "a" is the side dimension of a square core or equivalent in which "a.sup.2 " defines the core area A, and "b" is the winging height averaged between the primary and secondary windings, the coil constructed and arranged such that, in operation, the measured primary coil leakage inductance Lpe is given approximately, i.e. within .+-.25% of the calculated value of Lpe, by the equation:
- Lpe=(a/b+1).multidot.lw.sqroot.(Np/10).sup.2 uH
- where lw is in units of cms.
Dependencies are inferred from the claim text.