Knock control system for an internal combustion engine
First Claim
1. A knock control system for an internal combustion engine, comprising:
- a crank angle sensor for generating a crank angle signal in synchronization with the revolution of the internal combustion engine;
ignition timing calculating means for determining the ignition timing for each cylinder of the internal combustion engine based on the crank angle signal;
an ignition coil for applying a high ignition voltage to a spark plug of a cylinder to be controlled in response to the ignition timing;
ionic current detecting means for detecting an ionic current flowing through a spark plug of each cylinder immediately following ignition control to generate an ionic current detection signal;
knock detecting means for determining the presence of a knock in the internal combustion engine based on the ionic current detection signal;
knock control means for delaying the ignition timing by a predetermined amount when a knock has been detected;
wherein the knock detecting means comprises;
waveform processing means for extracting a knock signal waveform in the form of a knock pulse string from the ionic current detection signal; and
counting means for counting the number of pulses contained in the knock pulse string based on respective pulse edges in the knock pulse string;
whereby the knock control means determines the delay amount based on a count value of the pulses.
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Accused Products
Abstract
A knock control system for an internal combustion engine which subjects a knock signal waveform superposed on an ionic current to pulse processing so as to improve a signal-to-noise (SN) ratio, thereby achieving higher reliability thereof without adding to cost. The knock control system for the internal combustion engine is equipped with: a device for deciding the ignition timing for each cylinder based on a crank angle signal; an ignition coil which applies high voltage to spark plugs according to the ignition timing; a device for detecting an ionic current flowing through an ignited spark plug; a device for detecting a knock from an ionic current detection signal; a device for correcting the ignition timing by delaying it when a knock has been detected; a waveform processing device for extracting a knock signal waveform from the ionic current detection signal in the form of a knock pulse string; and a counter for counting the number of pulses from the pulse edges of the knock pulse string. A knock controller decides the amount of delay based on the count value of the pulses.
45 Citations
20 Claims
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1. A knock control system for an internal combustion engine, comprising:
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a crank angle sensor for generating a crank angle signal in synchronization with the revolution of the internal combustion engine; ignition timing calculating means for determining the ignition timing for each cylinder of the internal combustion engine based on the crank angle signal; an ignition coil for applying a high ignition voltage to a spark plug of a cylinder to be controlled in response to the ignition timing; ionic current detecting means for detecting an ionic current flowing through a spark plug of each cylinder immediately following ignition control to generate an ionic current detection signal; knock detecting means for determining the presence of a knock in the internal combustion engine based on the ionic current detection signal; knock control means for delaying the ignition timing by a predetermined amount when a knock has been detected; wherein the knock detecting means comprises; waveform processing means for extracting a knock signal waveform in the form of a knock pulse string from the ionic current detection signal; and counting means for counting the number of pulses contained in the knock pulse string based on respective pulse edges in the knock pulse string; whereby the knock control means determines the delay amount based on a count value of the pulses. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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Specification