Ignition timing retard angle control apparatus for internal combustion engine
First Claim
1. An ignition retard angle control for use in an internal combustion engine, comprising:
- first means for detecting vibrations of the engine to produce an output in the form of an electrical signal;
second means for discriminating part of the output signal of said first means in a characteristic frequency range in which a knock-induced vibration component appears remarkably when a knock is generated;
third means for amplifying an output signal of said second means at a first amplification degree;
fourth means for rectifying the output signal of said second means;
fifth means for averaging out an output signal of said fourth means;
sixth means for amplifying an output signal of said fifth means at a second amplification degree, said first and second amplification degrees being determined in such a manner that the peak of the instantaneous values of the amplitude of the output signal of said third means exceeds the instantaneous value of the amplitude of the output signal of said sixth means only in the presence of a knock;
seventh means for comparing the output signals of said third and sixth means with each other to produce a knock signal showing the presence of a knock when the instantaneous value of the output signal of said third means exceeds that of the output signal of said sixth means; and
eighth means for generating a voltage signal having an amplitude corresponding to an ignition advance angle determined by the number of revolutions per unit time of the engine, the amplitude of said voltage signal being changed in a manner to retard the ignition advance angle by a predetermined amount in response to the generation of the knock signal.
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Accused Products
Abstract
An ignition retard angle control apparatus for an internal combustion engine is disclosed. This control system comprises a vibration sensor for detecting engine vibrations, a filter for discriminating part of the output of the sensor in a characteristic frequency range where a knock-induced vibration component appears remarkably when a knock is generated, an amplifier for amplifying the output signal of the filter, an averaging/amplifying device for macroscopically averaging and amplifying the output signal of the filter, a comparator for comparing the output of the amplifier with those of the averaging/amplifying device and producing an output signal when the former is larger than the latter, an engine rpm detector for detecting the engine speed, and a voltage signal generator circuit responsive to the output signals of the comparator and the engine rpm detector and having an output of an amplitude corresponding to the ignition advance angle determined in accordance with the engine rpm, the voltage signal generator circuit changing the amplitude of the output voltage thereof in a manner to retard the ignition advance angle by a predetermined amount in response to an output signal of the comparator.
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Citations
16 Claims
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1. An ignition retard angle control for use in an internal combustion engine, comprising:
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first means for detecting vibrations of the engine to produce an output in the form of an electrical signal; second means for discriminating part of the output signal of said first means in a characteristic frequency range in which a knock-induced vibration component appears remarkably when a knock is generated; third means for amplifying an output signal of said second means at a first amplification degree; fourth means for rectifying the output signal of said second means; fifth means for averaging out an output signal of said fourth means; sixth means for amplifying an output signal of said fifth means at a second amplification degree, said first and second amplification degrees being determined in such a manner that the peak of the instantaneous values of the amplitude of the output signal of said third means exceeds the instantaneous value of the amplitude of the output signal of said sixth means only in the presence of a knock; seventh means for comparing the output signals of said third and sixth means with each other to produce a knock signal showing the presence of a knock when the instantaneous value of the output signal of said third means exceeds that of the output signal of said sixth means; and eighth means for generating a voltage signal having an amplitude corresponding to an ignition advance angle determined by the number of revolutions per unit time of the engine, the amplitude of said voltage signal being changed in a manner to retard the ignition advance angle by a predetermined amount in response to the generation of the knock signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An ignition retard angle control apparatus for an internal combustion engine, comprising:
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first means for detecting engine vibrations to produce an output in the form of an electrical signal; second means for discriminating part of the output of said first means in characteristic frequency range in which a knock-induced vibration component appears remarkably when a knock is generated; third means for receiving an output signal of said second means and for amplifying the same at a first amplification degree; fourth means for receiving the output signal of said second means for averaging out the same signal and for amplifying the same signal at a second amplification degree, said first and second amplification degrees being determined in such a manner that an output of said third means exceeds the output of said fourth means only in the presence of a knock; fifth means for comparing the outputs of said third and fourth means with each other so as to produce a knock signal indicating the presence of a knock only when the output of said third means exceeds that of said fourth means; sixth means for detecting the number of revolutions of the engine per unit time; seventh means for producing a voltage signal for determining an engine ignition timing in response to an output signal of said sixth means and said knock signal, wherein the amplitude of said voltage signal corresponds to an ignition advance angle for determining the ignition timing and changes with time in a manner so as to increase the ignition advance angle at a predetermined rate and as to retard the ignition advance angle at the time point of generation of the knock signal by a predetermined amount when said knock signal is generated and changes again so as to increase again the ignition advance angle at said predetermined rate from the value thereof at the time point at which the knock signal is disappeared. - View Dependent Claims (15, 16)
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Specification