Mitsubishi Denki Kabushiki Kaisha

Mitsubishi Electric Corporation

Mitsubishi Denki Kabushiki Kiasha

Koichi Okamura

Mitsuru Koiwa

Yasuhiro Takahashi

Yutaka Ohashi

Yasuyoshi Hatazawa

Hisanori Nobe

Mituru Koiwa

Kimihiko Tanaya

Tsutomu Morishita

Toshio Uchida

Takeshi Shimizu

Yusuke Naruse

Shu Sasaki

Masayuki Ikeuchi

Takahiko Inada

Shingo Morita

Haruyuki Matsuo

Futoshi Aida

Kazuya Hamada

Yutaka Ohhashi

Kenji Matsushita

An internal-combustion-engine combustion condition detection apparatus that can accurately comprehend a combustion condition is obtained. The internal-combustion-engine combustion condition detection apparatus includes an ion-current detection device () that detects an ion current generated during combustion and ignition devices including a first ignition device () having a first ignition plug () that causes main combustion in a combustion chamber () and a second ignition device () having a second ignition plug () disposed in the same combustion chamber () as and spaced apart from the first ignition plug () of the first ignition device (); the ion-current detection device () detects a combustion ion current that is generated in the second ignition device () regardless of whether or not ignition is performed by the second ignition device (), thereby detecting pre-ignition or a precursor phenomenon of pre-ignition.

Internal-combustion-engine combustion condition detection apparatus

An ignition device, including: an ignition coil () having a primary coil and a secondary coil; a switching element () for causing a primary current to be conducted through and shut off from the primary coil of the ignition coil; a waveform shaping circuit () for shaping a waveform of an ignition signal transmitted from an outside through a signal line to supply a conduction signal thus obtained to the switching element; ion current detecting means () connected to the secondary coil of the ignition coil, for detecting an ion current flowing through the secondary coil; and ion signal generating means () for outputting an ion signal, which indicates the ion current detected for a predetermined period after the conduction signal of the waveform shaping circuit has been turned off, to the outside through the signal line while invalidating the conduction signal from the waveform shaping circuit.

Ignition device of ignition control system for an internal combustion engine

The ignition apparatus includes an electronic control unit and an igniter. The igniter detects ions resulting from ignition, and sends an ion current output signal to the electronic control unit. The igniter has a waveform shaping circuit and an ion current detecting/outputting circuit. The waveform shaping circuit is adapted such that a voltage at an input terminal thereof becomes higher than a predetermined reference voltage to turn the switching element ON when the ignition signal is caused to flow through an electric load. The ion current detecting/outputting circuit has an output terminal which is connected to the input terminal and outputs therefrom an ion current output signal obtained as a result of conversion of an ion current, and is adjusted such that the voltage at the input terminal at the time when the ion current output signal is outputted to the electronic control unit becomes lower than the reference voltage.

Ignition apparatus for an internal combustion engine

A misfire detection apparatus of an internal combustion engine. The misfire detection apparatus includes an angle sensor for detecting rotation angle of the internal combustion engine, an ECU for performing fuel injection and ignition control based on rotation information of the angle sensor, an ignition coil for generating a high voltage for ignition based on a drive signal from the ECU, and an spark plug, as the high voltage for ignition of the ignition coil is applied, for generating an ignition spark and igniting an air fuel mixture. The misfire detection apparatus applies a bias voltage to the spark plug, detects an ion current, makes a misfire determination based on the ion current detection, and makes a failure determination based on time change of rotation information of the internal combustion engine when misfires occur successively in a specific cylinder of the internal combustion engine.

Misfire detection apparatus of internal combustion engine

A misfire detection apparatus of an internal combustion engine for detecting combustion or a misfire of an air fuel mixture in the internal combustion engine based on an ion current generated at the combustion time of the air fuel mixture. The misfire detection apparatus includes ion current detection means and misfire determination means. The ion current detection means detects the ion current responsive to the amount of ions occurring in a cylinder just after combustion of the air fuel mixture in the cylinder in the internal combustion engine. The misfire determination means calculates a predetermined function based on the ion current detection value and determines that the condition is combustion when the magnitude exceeds a threshold value.

Ion current detection signal output section for outputting an ion current detection signal including a failure determination signal of an ignition operation is provided, and a failure determination as well as a combustion state can be performed based on this ion current detection signal.

Combustion state detection and failure determination apparatus of an 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.

Combustion state detection apparatus for internal combustion engine

To obtain a knock control apparatus for internal-combustion engine having a function of judging whether or not the causes for failure have been solved for returning to normal knock control at the time of the solution, and capable of easily judging failure even in a failure mode in which it is difficult to raise the filter value and it is difficult to judge the failure. A fail control means includes: a failure judgment unit for judging failure for each cylinder based on output from a background level setting unit and a knock suppression and control unit ; number of fail cylinders judgment unit for judging the number of fail cylinders based on output from the failure judgment unit ; a retard angle changing unit for changing at least the real retard angle of a fail cylinder based on output from the knock suppression and control unit , the failure judgment unit and the number of fail cylinders judgment unit ; and a normal judgment returning unit for returning to normal ignition timing retard when a cylinder under judgment for failure meets normal judgment requirements based on the output from the background level setting unit and the retard angle changing unit

Knock control apparatus for internal-combustion engine

A knock control apparatus for an internal combustion engine includes a knock detector for extracting a vibration component superposed on an ion current, and waveform shaping it at a predetermined threshold value to generate a train of knock pulses (Kp) of which the number of pulses indicates a knock intensity of a knock generated in the internal combustion engine, and an engine control unit for counting the number of knock pulses (npn) in the knock pulse train (Kp) output from the knock detector. The engine control unit judges, based on the number of knock pulses (npn), whether or not a knock is occurring. The engine control unit performs a peak hold of the number of knock pulses to calculate the knock judgement threshold value (BGL) by multiplying the number of pulses by (&agr;). Thus, precision in knock judgement is improved by performing knock judgement based on a maximum value (MAX) of the number of knock pulses (npn).

Knock control apparatus for internal combustion engine

A misfire detecting apparatus for an internal combustion engine detects only an ion current due to combustion of an air/fuel mixture regardless of a leakage current when combustion: takes place normally. The apparatus includes circuitry for detecting an ion current generated within the engine cylinder immediately after combustion, circuitry for detecting a leakage current occurring between electrodes of a spark plug , a first waveform shaper for shaping the ion current into a pulse signal indicating a combustion or misfire event by comparing the pulse signal with a first threshold value for deciding the ion current, the first threshold value being set on the basis of a level of the ion current upon rising thereof, the ion current being superposed on the leakage current, a second waveform shaper for shaping the ion current as detected into a pulse signal through comparison with a second fixed threshold value which is fixed at a value smaller than the first threshold value, and a selector for selectively outputting as the combustion pulse signal either a shaped pulse signal outputted from the first waveform shaper upon detection of occurrence of the leakage current or a shaped pulse signal outputted from the second waveform shaper when no leakage current is detected.

Misfire detecting apparatus for internal combustion engine

To obtain a knock detection apparatus which may obtain a good knock pulse S/N even if an ionic current generation amount is changed by the change of a kind of fuel or plugs, a knock detection apparatus for detecting a knock generated, in an internal combustion engine, in which a vibratory component superimposed on an ionic current generated by combustion of fuel is extracted, the component that is equal to or more than a knock detection threshold value is shaped in waveform into a pulse waveform, a knock strength is calculated through counting and calculation process of the number of pulses of the pulse waveform by an engine controlling unit, an ignition timing is controlled on the basis of the knock strength, comprises a knock detection threshold value adjusting unit for changing the knock detection threshold value on the basis of information of an ionic current.

Knock detection apparatus

A device for detecting the knocking of an internal combustion engine, which maintains the background level at an optimum value irrespective of the knocking level, and features improved reliability by preventing the erroneous detection of noise or knocking when the knocking level is shifted. The device includes a counter for operating signals N of the knocking level from the ionic current, an averaging circuit A for operating an average knocking level AVE, a circuit A for operating a background level BGLA by using an offset value, a comparator for judging the knocking by comparing the signals of the knocking level with the background level, a circuit for judging the average knocking level that lies in a predetermined region, and a circuit for correcting the offset value depending on the result of judging the predetermined region, wherein the offset value is corrected toward a direction to cancel the increment or the decrement of the average knocking level depending on the predetermined region.

Device for detecting the knocking of an internal combustion engine

To provide a combustion condition detecting apparatus for an internal combustion engine, which may well detect the combustion conditions such as discrimination of a combustion cylinder and knock generating condition and may reduce a circuit scale therefor, there are provided an ignition coil provided for each cylinder; an ignition plug for discharging by the application of the ignition high tension voltage to ignite mixture within the cylinder; a bias circuit provided for each cylinder for applying a bias voltage to the ignition plug ; an ionic current detection circuit provided for each cylinder for detecting as an ionic current detection signal an ionic current generated in the cylinder that is immediately after the combustion of the mixture; a knock signal processing circuit provided one for a combination of a plurality of cylinders that are every two or more cylinders in ignition order on the basis of a sum of the ionic current detection signals; and an ECU for detecting the combustion condition of the ignition plug on the basis of the knock signal.

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Tokyo, Japan

Koichi Okamura