Mitsubishi Denki Kabushiki Kaisha

Toshio Uchida

Yasuhiro Takahashi

Koichi Okamura

Mitsuru Koiwa

Kimihiko Tanaya

Yoshiyuki Sera

Masakazu Dohi

A combustion condition detecting apparatus for an internal combustion engine has a current distributor that distributes an ion current, a band pass filter which extracts a knock vibration component from a current distributor output, a knock determination section which outputs a knock pulse if the extracted knock vibration component is larger than a knock detection threshold value, a combustion determination section which outputs a combustion pulse when an current distributor output is larger than a combustion pulse threshold value, an ignition signal determination section which makes a determination on the basis of an ignition signal as to whether energization of an ignition coil for ignition in another cylinder is started, and an ion current limiting section which limits its ion current output to the current distributor during a predetermined time period after the start of energization of the ignition coil for ignition in the another cylinder.

Combustion condition detection apparatus for an internal combustion engine

A knock control apparatus normalizes a knock frequency magnitude and a background noise level to substantially the same levels in all the engine operating conditions in consideration of a variation in an ionic current level due to an environment, the number of revolutions per minute of the engine, an engine load, etc. A frequency magnitude calculation part includes a frequency magnitude detector for detecting the magnitude of a specific frequency based on an output of an ionic current detector, an ionic current area calculator for calculating an ionic current area in a prescribed range during the combustion stroke of a cylinder concerned based on the output of the ionic current detector, a corrector for correcting the detected specific frequency magnitude based on the calculated ionic current area, a knock determiner for determining based on the corrected specific frequency magnitude whether the engine is knocking, and a control parameter correction amount setter for setting an amount of correction for an ignition timing control parameter based on the determination result.

Knock control apparatus for internal combustion engine

Based on an ionic current intensity determined by ionic current intensity learning means for determining the ionic current intensity based on an output from an ionic current detection circuit, at least one of a comparison reference value of a comparison reference value setting means and a control parameter correction amount of control parameter correction request amount setting means is corrected, so that, even in a case where fuel is mixed with additives, and a case where a non-standard spark plug is mounted, the ionic current amount fluctuation is accurately determined even if the amplitude of a knock signal varies due to ionic current intensity fluctuation, and correction of the comparison reference value corresponding to the ionic current intensity, or correction of the control parameter, is performed, to thereby prevent erroneous control based on erroneous knock detection, and securely achieve an excellent knock detection status and knock control status.

Knock control device for an internal combustion engine

To provide a knock control system for an internal combustion engine, with which appropriate ignition timing control for each cylinder can be made. The knock control system includes knock detectors outputting a knock detection signal; a unit setting a threshold value for a knock judgement performed on the knock detection signal; a unit performing a knock judgement based on the threshold value and the knock detection signal; a unit setting a control parameter correction request amount at least including ignition timing, based on the knock judgement result; a unit correcting the control parameter by setting a control parameter correction amount based on a control parameter correction request amount; and a variation correction unit performing a correction to reduce variation in a cylinder when at the knock detection result and the control parameter correction amount from at least one cylinder varies greatly with respect to other cylinders.

Knock control system for an internal combustion engine

A combustion state detection apparatus for an internal combustion engine has a detection period limit section, which limits a detection period of an ion current processed in misfire detection section or knock detection section.

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Hyogo, Japan

Toshio Uchida