Ignition timing control device for internal combustion engines

Claim 2

An ignition timing control device for an internal combustion engine, comprising: (a) a knocking sensor for detecting knocking of the engine; (b) a reference voltage generator for generating a reference voltage dependent on the level of an output signal from said knocking sensor; (c) a comparator for comparing said output signal from said knocking sensor with said reference voltage to generate a train of pulses in a number dependent on an amplitude of knocking; (d) an integrator for integrating an output signal from said comparator; (e) ignition timing controller means responsive to the level of the output voltage from said integrator for controlling the ignition timing of the internal combustion engine, said ignition timing controller means retarding said ignition timing at a fixed rate when knocking is detected, and advancing said ignition timing at a speed that is variable with an elapsed time during which no knocking is detected; and (f) control means triggerable by the output of said comparator for increasing a variation speed in the output signal level of said integrator during no knocking as time elapses, whereby said speed at which ignition timing of the internal combustion engine is advanced, is increased as time elapses.

Claim 3

The ignition timing control device of claim 1, wherein said control means comprises switching means for switching the rate at which an output voltage from said integrator drops from a slower mode to a faster mode upon elapse of a predetermined interval of time.

Claim 4

The ignition timing control device of claim 2, wherein said switching means comprises a timer coupled to said integrator for controlling an integrating time constant of said integrator.

Claim 5

The ignition timing control device of claim 1, wherein said control means comprises means for varying the variation speed in the output signal level of said integrator successively.

Claim 6

The ignition timing control device of claim 4, wherein said control means comprises means for generating a control signal whose signal level varies successively in proportion to the lapse of time, to increase the variation speed in the output signal level of said integrator successively.

Claim 7

The ignition timing control device of claim 1, wherein said integrator comprises an analog integrator.

Claim 8

The ignition timing control device of claim 1, wherein said integrator comprises a digital integrator.

Claim 9

An ignition timing control device for an internal combustion engine, comprising: (a) a knocking sensor for detecting knocking of the engine; (b) a reference voltage generator for generating a reference voltage dependent on the level of an output signal from said knocking sensor; (c) a comparator for comparing said output signal from said knocking sensor with said reference voltage to generate a train of pulses in a number dependent on an amplitude of knocking; (d) an integrator for integrating an output signal from said comparator, said integrator having selectable first and second integrating time constants, said first time constant being greater than said second time constant; (c) timer means triggerable by the output signal from said comparator, an output of said timer being coupled to said integrator for selecting between said first and second integrating time constants, said first time constant being selected when said timer means is performing a timing operation upon being triggered by said output signal from said comparator and said second time constant being selected after said timer means has completed said timing operation; and (f) ignition timing controller means responsive to an output from said integrator for controlling the ignition timing of the internal combustion engine, said ignition timing controller means retarding said ignition timing at a fixed rate when knocking is detected, and advancing said ignition timing at a speed that is variable with an elapsed time during which no knocking is detected.

Claim 10

An ignition timing control device for an internal combustion engine, comprising: (a) a knocking sensor for detecting knocking of the engine; (b) a reference voltage generator for generating a reference voltage dependent on the level of an output signal from said knocking sensor; (c) a comparator for comparing said output signal from said knocking sensor with said reference voltage to generate a train of pulses in a number dependent on an amplitude of knocking; (d) an integrator for integrating an output signal from said comparator, said integrator having selectable first and second integrating time constants, said first time constant being greater than said second time constant; (c) timer means triggerable by the output signal from said comparator, an output of said timer being coupled to said integrator for selecting between said first and second integrating time constants, said first time constant being selected when said timer means is performing a timing operation upon being triggered by said output signal from said comparator and said second time constant being selected after said timer means has completed said timing operation; and (f) ignition timing controller means responsive to an output from said integrator for controlling the ignition timing of the internal combustion engine, said ignition timing controller means retarding said ignition timing at a fixed rate when knocking is detected, and advancing said ignition timing at a speed that is variable with an elapsed time during which no knocking is detected.

Claim 11

An ignition timing control device for an internal combustion engine, comprising: (a) a knocking sensor for detecting knocking of the engine; (b) a reference voltage generator for generating a reference voltage dependent on the level of an output signal from said knocking sensor; (c) a comparator for comparing said output signal from said knocking sensor with said reference voltage to generate a train of pulses in a number dependent on an amplitude of knocking; (d) an integrator for integrating an output signal from said comparator; said integrator having a selectable integrating source voltage; (c) voltage signal generating means triggerable by the output signal from said comparator, for producing a voltage signal varying monotonically between first and second levels in response to said pulses, said voltage signal being applied to said integrator to select said integrating source voltage such that said integrating source voltage is increased when there is no knocking within a predetermined interval of time; and (f) ignition timing controller means responsive to an output from said integrator for controlling the ignition timing of the internal combustion engine, said ignition timing controller means retarding said ignition timing at a fixed rate when knocking is detected, and advancing said ignition timing at a speed that is variable with an elapsed time during which no knocking is detected.

Claim 12

An ignition timing control device for an internal combustion engine, comprising: (a) a knocking sensor for detecting knocking of the engine; (b) a reference voltage generator for generating a reference voltage dependent on the level of an output signal from said knocking sensor; (c) a comparator for comparing said output signal from said knocking sensor with said reference voltage to generate a train of pulses in a number dependent on an amplitude of knocking; (d) an integrator for integrating an output signal from said comparator; said integrator having a selectable integrating source voltage; (c) voltage signal generating means triggerable by the output signal from said comparator, for producing a voltage signal varying monotonically between first and second levels in response to said pulses, said voltage signal being applied to said integrator to select said integrating source voltage such that said integrating source voltage is increased when there is no knocking within a predetermined interval of time; and (f) ignition timing controller means responsive to an output from said integrator for controlling the ignition timing of the internal combustion engine, said ignition timing controller means retarding said ignition timing at a fixed rate when knocking is detected, and advancing said ignition timing at a speed that is variable with an elapsed time during which no knocking is detected.