Electronic ignition system with automatic ignition advancement and retardation

Claim 2

In the ignition system of an internal combustion engine, in combination, igniting means having a control input and operative for igniting a combustion mixture in an engine cylinder of the engine upon receipt of an ignition signal at said control input; transducer means for determining the value of at least one engine operating variable; a timing circuit comprised of energy-storing timing means, first means operative for effecting a first change of stored energy of said energy-storing timing means during the time the engine crankshaft moves through a predetermined angle, and second means operative subsequent to the completion of said first change of stored energy for effecting an opposite second change of stored energy of said timing means, at least a predetermined one of said first and second means comprising means connected to said transducer means and operative for effecting the respective change of stored energy of said energy-storing timing means at a rate of enErgy change dependent upon the value of said engine operating variable; and ignition signal generating means connected to said energy-storing timing means and connected to the control input of said igniting means and operative for applying to said control input of said igniting means an ignition signal upon completion of said second change of stored energy, wherein said first and second means together comprise synchronizing means for generating a crankshaft-positionsynchronizing signal when the engine crankshaft assumes a predetermined angular orientation, bistable frequency-dividing means having an input connected to said synchronizing means for receipt of crankshaft-position-synchronizing signals therefrom, and having two stable states, and wherein said first means comprises means operative for effecting said first change of stored energy when said bistable means is in a predetermined one of the two stable states thereof, and wherein said second means comprises means operative for effecting said second change of stored energy when said bistable means is in the other of the two stable states thereof.

Claim 3

The system defined in claim 1, wherein said adjusting means comprises means operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of the engine speed.

Claim 4

The system defined in claim 1, wherein said adjusting means comprises means operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of the pressure prevailing in the air-intake passage of the engine.

Claim 5

The system defined in claim 1, wherein said adjusting means comprises means operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of the engine speed and the value of the pressure prevailing in the air-intake passage of the engine.

Claim 6

In the ignition system of an internal combustion engine, in combination, igniting means having a control input and operative for igniting a combustion mixture in an engine cylinder of the engine upon receipt of an ignition signal at said control input; transducer means for determining the value of at least one engine operating variable; a timing circuit comprised of energy-storing timing means, first means operative for effecting a first change of stored energy of said energy-storing timing means during the time the engine crankshaft moves through a predetermined angle, and second means operative subsequent to the completion of said first change of stored energy for effecting an opposite second change of stored energy of said timing means, at least a predetermined one of said first and second means comprising means connected to said transducer means and operative for effecting the respective change of stored energy of said energy-storing timing means at a rate of energy change dependent upon the value of said engine operating variable; and ignition signal generating means connected to said energy-storing timing means and connected to the control input of said igniting means and operative for applying to said control input of said igniting means an ignition signal upon completion of said second change of stored energy, wherein said energy-storing timing means comprises energy-storing timing capacitor means, and wherein said first means comprises first constant current source means connected to said capacitor means and operative for effecting said first change of stored energy by establishing a flow of a first current through said capacitor means in a predetermined first direction, and wherein said second means comprises second constant current source means connected to said capacitor means and operative for effecting said second change of stored energy by establishing a flow of a second current through said capacitor means in opposite second Direction, with the constant current source means of at least one predetermined one of said first and second means being an adjustable constant source means and further including adjusting means connected to said adjustable constant current source means and connected to said transducer means and operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of said engine operating variable, wherein said first and second means together comprise synchronizing means for generating a crankshaft-position-synchronizing signal when the engine crankshaft assumes a predetermined angular orientation, bistable frequency-dividing means having an input connected to said synchronizing means for receipt of crankshaft-position-synchronizing signals therefrom, and having two stable states, and wherein said first constant current source means comprises means operative for establishing said flow of said first current when said bistable means is in a predetermined one of the two stable states thereof, and wherein said second constant current source means comprises means operative for establishing said flow of said second current when said bistable means in the other of the two stable states thereof.

Claim 7

In the ignition system of an internal combustion engine, in combination, igniting means having a control input and operative for igniting a combustion mixture in an engine cylinder of the engine upon receipt of an ignition signal at said control input; transducer means for determining the value of at least one engine operating variable; a timing circuit comprised of energy-storing timing means, first means operative for effecting a first change of stored energy of said energy-storing timing means during the time the engine crankshaft moves through a predetermined angle, and second means operative subsequent to the completion of said first change of stored energy for effecting an opposite second change of stored energy of said timing means, at least a predetermined one of said first and second means comprising means connected to said transducer means and operative for effecting the respective change of stored energy of said energy-storing timing means at a rate of energy change dependent upon the value of said engine operating variable; and ignition signal generating means connected to said energy-storing timing means and connected to the control input of said igniting means and operative for applying to said control input of said igniting means an ignition signal upon completion of said second change of stored energy, wherein said energy-storing timing means comprises energy-storing timing capacitor means, and wherein said first means comprises first constant current source means connected to said capacitor means and operative for effecting said first change of stored energy by establishing a flow of a first current through said capacitor means in a predetermined first direction, and wherein said second means comprises second constant current source means connected to said capacitor means and operative for effecting said second change of stored energy by establishing a flow of a second current through said capacitor means in opposite second Direction, with the constant current source means of at least one predetermined one of said first and second means being an adjustable constant source means and further including adjusting means connected to said adjustable constant current source means and connected to said transducer means and operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of said engine operating variable, wherein said first and second means together comprise synchronizing means for generating a crankshaft-position-synchronizing signal when the engine crankshaft assumes a predetermined angular orientation, bistable frequency-dividing means having an input connected to said synchronizing means for receipt of crankshaft-position-synchronizing signals therefrom, and having two stable states, and wherein said first constant current source means comprises means operative for establishing said flow of said first current when said bistable means is in a predetermined one of the two stable states thereof, and wherein said second constant current source means comprises means operative for establishing said flow of said second current when said bistable means in the other of the two stable states thereof.

Claim 8

The system defined in claim 5, wherein said synchronizing means comprises signal-generating means for generating a pulse when the engine crankshaft assumes a predetermined angular orientation and pulse-shaping means having an input connected to the output of said signal-generating means and having an output connected to said input of said bistable frequency-dividing means and operative for shaping the pulse generated by said signal-generating means to form a shaped pulse constituting said crankshaft-position-synchronizing signal.

Claim 9

The system defined in claim 6, wherein said signal-generating means comprises means for generating a pulse when the engine crankshaft assumes any of four predetermined rotational positions equiangularly spaced from each other.

Claim 10

In the ignition system of an internal combustion engine, in combination, igniting means having a control input and operative for igniting a combustion mixture in an engine cylinder of the engine upon receipt of an ignition signal at said control input; transducer means for determining the value of at least one engine operating variable; a timing circuit comprised of energy-storing timing means, first means operative for effecting a first change of stored energy of said energy-storing timing means during the time the engine crankshaft moves through a predetermined constant angle, and second means operative subsequent to the completion of said first change of stored energy for effecting an opposite second change of stored energy of said timing means, at least a predetermined one of said first and second means comprising means connected to said transducer means and operative for effecting the respective change of stored energy of said energy-storing timing means at a rate of energy change dependent upon the value of said engine operating variable; and ignition signal generating means connected to said energy-storing timing means and connected to the control input of said igniting means and operative for applying to said control input of said igniting means an ignition signal upon completion of said second change of stored energy, wherein said energy-storing timing means comprises energy-storing timing capacitor means, and wherein said first means comprises first constant current source means connected to said capacitor means and operative for effecting said first change of stored energy by establishing a flow of a first current through said capacitor means in a predetermined first direction, and wherein said second means comprises second constant current source means connected to said capacitor means and operative for effecting said second change of stored energy by establishing a flow of a second current through said capaciTor means in opposite second direction, with the constant current source means of at least said predetermined one of said first and second means being an adjustable constant current source means and further including adjusting means connected to said adjustable constant current source means and connected to said transducer means and operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of said engine operating variable, wherein said igniting means comprises inductive means and additional means having a control input for receipt of a control pulse and operative for maintaining a flow of current through said inductive means so long as a control pulse is applied to said control input, whereby upon termination of such control pulse the current flow through the inductive means is interrupted and an ignition voltage is generated, and wherein said first and second means together comprise synchronizing means for initiating generation of a synchronizing pulse when the crankshaft assumes a first predetermined rotational orientation and for terminating generation of such synchronizing pulse when the crankshaft assumes a second predetermined rotational orientation, and wherein said first means includes means for causing said first change of stored energy to last for the duration of said synchronizing pulse, and further including means for generating a further pulse having a duration coincident with the duration of said second change of stored energy, and means for applying both said synchronizing pulse and said further pulse to said control input of said additional means so that said pulses together form a longer composite pulse serving to maintain said flow of current through said inductive means for the combined duration of said synchronizing pulse and said further pulse.

Claim 11

In the ignition system of an internal combustion engine, in combination, igniting means having a control input and operative for igniting a combustion mixture in an engine cylinder of the engine upon receipt of an ignition signal at said control input; transducer means for determining the value of at least one engine operating variable; a timing circuit comprised of energy-storing timing means, first means operative for effecting a first change of stored energy of said energy-storing timing means during the time the engine crankshaft moves through a predetermined constant angle, and second means operative subsequent to the completion of said first change of stored energy for effecting an opposite second change of stored energy of said timing means, at least a predetermined one of said first and second means comprising means connected to said transducer means and operative for effecting the respective change of stored energy of said energy-storing timing means at a rate of energy change dependent upon the value of said engine operating variable; and ignition signal generating means connected to said energy-storing timing means and connected to the control input of said igniting means and operative for applying to said control input of said igniting means an ignition signal upon completion of said second change of stored energy, wherein said energy-storing timing means comprises energy-storing timing capacitor means, and wherein said first means comprises first constant current source means connected to said capacitor means and operative for effecting said first change of stored energy by establishing a flow of a first current through said capacitor means in a predetermined first direction, and wherein said second means comprises second constant current source means connected to said capacitor means and operative for effecting said second change of stored energy by establishing a flow of a second current through said capaciTor means in opposite second direction, with the constant current source means of at least said predetermined one of said first and second means being an adjustable constant current source means and further including adjusting means connected to said adjustable constant current source means and connected to said transducer means and operative for varying the magnitude of the current flowing through said capacitor means from said adjustable constant current source means in dependence upon the value of said engine operating variable, wherein said igniting means comprises inductive means and additional means having a control input for receipt of a control pulse and operative for maintaining a flow of current through said inductive means so long as a control pulse is applied to said control input, whereby upon termination of such control pulse the current flow through the inductive means is interrupted and an ignition voltage is generated, and wherein said first and second means together comprise synchronizing means for initiating generation of a synchronizing pulse when the crankshaft assumes a first predetermined rotational orientation and for terminating generation of such synchronizing pulse when the crankshaft assumes a second predetermined rotational orientation, and wherein said first means includes means for causing said first change of stored energy to last for the duration of said synchronizing pulse, and further including means for generating a further pulse having a duration coincident with the duration of said second change of stored energy, and means for applying both said synchronizing pulse and said further pulse to said control input of said additional means so that said pulses together form a longer composite pulse serving to maintain said flow of current through said inductive means for the combined duration of said synchronizing pulse and said further pulse.