Abstract: A combustion state detection apparatus includes an ion detection device that detects ions generated in a combustion chamber, an end detection device that detects ion signal end timing after spark timing obtained from the ion detection device, and a combustion diagnosis device that sets comparative timing to be compared with the end timing to determine abnormal combustion when the end timing is advanced from the comparative timing. The diagnosis device sets a smoothed value smoothed using various ion signal end timing values to set a ratio of the smoothed value and the spark timing and sets the comparative timing by making the ratio variable at predetermined timing with respect to the smoothed value. Hence, abnormal combustion in the internal combustion engine can be detected without causing a change in detection accuracy even with a change in calibration or environment and matching man hours for abnormal combustion detection can be reduced.

Abstract: An ignition controlling apparatus that can diagnose a state of spark discharge in an internal combustion engine, and perform appropriate actions based on the diagnostic results. In the internal combustion engine ignition controlling apparatus, a signal extracting device extracts an ion current that is generated together with combustion of a gas mixture inside a combustion chamber by spark discharge of an ignition apparatus based on an ignition signal of an ignition coil, includes a signal diagnosing device that sets a predetermined detection zone from a period in a single stroke of an internal combustion engine from a first spark discharge commencement until after a last spark discharge completion, and that determines an ignition state based on parameters included in the signal extracted in this detection zone, and controls the internal combustion engine in response to this ignition state.

Abstract: Provided is a failure diagnosis system which can diagnose whether or not a sensitivity adjustment part is in failure. The failure diagnosis system includes: a plurality of sensors; various sensors that detect operating conditions of a device; a plurality of sensitivity adjustment parts that adjust receiver sensitivities of sensor signals from the plurality of sensors based on the detected operating conditions; and a failure diagnosis part that diagnoses whether or not the plurality of sensitivity adjustment parts are in failure. The failure diagnosis part detects a failure condition of a sensitivity adjustment part when a difference between a comparison value calculated based on a maximum value of the adjusted sensor signals from the plurality of sensitivity adjustment parts at a given interval, and a maximum value of the adjusted sensor signal from the sensitivity adjustment part to be diagnosed at the given interval is larger than a given amount.

Abstract: An ignition controlling apparatus is provided that can diagnose a state of spark discharge in an internal combustion engine, and perform appropriate actions based on the diagnostic results. In the internal combustion engine ignition controlling apparatus, a controlling apparatus has a signal extracting device that extracts an ion current that is generated together with combustion of a combustible gas mixture inside a combustion chamber by a spark discharge of an ignition apparatus based on an ignition signal of an ignition coil, includes a signal diagnosing device that sets a predetermined detection zone from a period in a single stroke of an internal combustion engine from a first spark discharge commencement until after a last spark discharge completion, and that determines an ignition state based on parameters included in the signal extracted in this detection zone, and controls the internal combustion engine in response to this ignition state.

Abstract: The internal-combustion-engine ignition diagnosis apparatus is configured in such a way that the first duration setting unit sets the first detection duration in a predetermined duration including a time instant when the spark discharge is generated, the second duration setting unit sets the second detection duration after the first detection duration, the diagnosis unit determines normality of the spark discharge, based on a signal state in the second detection duration, and regardless of the signal state in the second detection duration, determines abnormality of the spark discharge, based on a signal state in the first detection duration.

Abstract: A combustion state detection apparatus includes an ion detection device that detects ions generated in a combustion chamber, an end detection device that detects ion signal end timing after spark timing obtained from the ion detection device, and a combustion diagnosis device that sets comparative timing to be compared with the end timing to determine abnormal combustion when the end timing is advanced from the comparative timing. The diagnosis device sets a smoothed value smoothed using various ion signal end timing values to set a ratio of the smoothed value and the spark timing and sets the comparative timing by making the ratio variable at predetermined timing with respect to the smoothed value. Hence, abnormal combustion in the internal combustion engine can be detected without causing a change in detection accuracy even with a change in calibration or environment and matching man hours for abnormal combustion detection can be reduced.

Abstract: A combustion state detection device for an internal combustion engine includes: an ignition control unit that controls activation of a primary winding for ignition; a comparison value setting unit that sets a comparison value with respect to an ion signal; and a combustion state discrimination unit that determines the occurrence of misfire depending on the magnitude of the ion signal with respect to the comparison value; wherein the ignition control unit, after generating a spark, reactivates the primary winding at least one time during one combustion stroke so that an induction voltage similar to that generated in the secondary winding at around a time when the primary winding begins to be activated for the purpose of starting combustion is generated in the secondary winding.

Abstract: A combustion state detecting apparatus for an internal combustion engine includes: an ignition plug (2) for generating a spark discharge for igniting an air-fuel mixture in a combustion chamber; an ignition coil (1) for supplying a high voltage to cause the ignition plug (2) to generate the spark discharge; and an ECU (3) for feeding a driving signal for driving the ignition coil (1). An electromotive force (secondary voltage) due to electromagnetic induction when a primary current is caused to flow through a primary winding of the ignition coil (1) in response to the driving signal from the ECU (3) is applied to the ignition plug (2) to detect an ion current generated in the combustion chamber to detect a combustion state in the ignition plug based thereon.

Abstract: There is provided an ignition diagnosis apparatus that detects ignition abnormality in a multi-point-ignition internal combustion engine.

Abstract: A combustion state detection apparatus for an internal combustion engine, includes convexity detection means (30) for detecting that domain within the detection interval in which the change shape of the ionic current is upwardly convex, on the basis of the ionic current data extracted by data extraction means (20), and preignition decision means (40) including comparison setting means for setting a comparison value with which the upwardly convex domain is compared, and functioning to decide the occurrence of the preignition or the premonitory phenomenon thereof when the upwardly convex domain lies at a timing earlier than the comparison value, wherein the convexity detection means (30) includes leak current judgment means for judging the appearance of a leak current across electrodes, and it enables the detection of the upwardly convex domain when the appearance of the leak current has been judged.

Abstract: A knock detection apparatus for an internal combustion engine can accurately detect the occurrence of a knock without an influence of a noise component even if the noise component having the same frequency as a knock vibration superposes on an ionic current signal. The apparatus includes an ionic current detection section, a knock signal detection section for detecting a knock signal based on an ionic current, a crank angle sensor for detecting a crank angle corresponding to a rotational position of the engine, a window setting section for setting a noise detection window, a noise component detection section for detecting a noise component in the window, and a knock determination section for determining the occurrence of a knock based on a relation between the noise component and the knock signal. The window setting section sets the window after a predetermined crank angle corresponding to an end of a combustion stroke of the engine.

Abstract: An internal-combustion-engine combustion condition detection apparatus is provided with an ignition means that makes an ignition plug ignite a fuel; an ignition control means that controls the operation of the ignition means; an ion-current detection means that detects an ion current generated; an ion current detection range setting means that sets an ion-current detection range; a preignition detection means that detects preignition within a detection range to be set; a leakage current detection range setting means that sets a leakage-current detection range; and a leakage current determination means that determines whether or not a smolder exists, based on a current detected, within a detection range to be set, by the ion-current detection means. The ignition control means includes a non-combustion-stroke ignition control means; the leakage-current detection range set by the leakage current detection range setting means is set within the non-combustion stroke.

Abstract: There is provided a combustion state detecting apparatus capable of detecting combustion-state abnormality in an internal combustion engine. A comparison timing is set to be advanced in terms of the rotation angle of the crankshaft of an internal combustion engine with respect to the ending timing of an electric quantity based on an ion that occurs when ignition is performed normally through a predetermined ignition signal among the plurality of ignition signals; in the case where, as a result of the comparison between the detected ending timing of an electric quantity based on an ion and the comparison timing, the ending timing is advanced in terms of the rotation angle of the crankshaft with respect to the comparison timing, it is determined that the combustion based on ignition through the predetermined ignition signal is abnormal.

Abstract: There is provided an ignition diagnosis apparatus that detects ignition abnormality in a multi-point-ignition internal combustion engine.

Abstract: Disclosed is a combustion state detection apparatus for an internal combustion engine, which is capable of detecting abnormal combustion with high accuracy. The combustion state detection apparatus for an internal combustion engine includes: a variety of sensors; an ignition coil; an ignition plug; a transistor; a switching control unit; an ion current detection unit; and abnormal combustion detection units for determining that abnormal combustion has occurred in a case where a crank angle at a point of time when the ion current exceeds a predetermined current value or when the ion current that exceeds the predetermined current value reaches a peak value thereof is on a spark-advance side compared with a crank angle for determining abnormal combustion. The switching control unit ends the spark discharge at a predetermined timing while the spark discharge is in progress after the primary current is shut off and the spark discharge is generated.

Abstract: The ion current detector includes: an ion bias circuit for supplying a bias voltage to an electrode of the ignition plug so as to cause the ignition plug to generate a spark discharge; and an ion current detection circuit for detecting an ion current generated in a combustion chamber by the spark discharge and for amplifying the detected ion current to output an ion current detection signal. The ion current detection circuit amplifies the ion current at an ion current amplification factor switched between a time when an ignition signal is supplied and a time when the ignition signal is not supplied. Specifically, when the ignition signal is supplied, the ion current amplification factor is set to a low value (approximately 50). When the ignition signal is not supplied, the ion current amplification factor is set to a high value (250 or more).

Abstract: Disclosed is a combustion state detection apparatus for an internal combustion engine, which is capable of detecting abnormal combustion with high accuracy. The combustion state detection apparatus for an internal combustion engine includes: a variety of sensors; an ignition coil; an ignition plug; a transistor; a switching control unit; an ion current detection unit; and abnormal combustion detection units for determining that abnormal combustion has occurred in a case where a crank angle at a point of time when the ion current exceeds a predetermined current value or when the ion current that exceeds the predetermined current value reaches a peak value thereof is on a spark-advance side compared with a crank angle for determining abnormal combustion. The switching control unit ends the spark discharge at a predetermined timing while the spark discharge is in progress after the primary current is shut off and the spark discharge is generated.

Abstract: A combustion state detecting apparatus for an internal combustion engine includes: an ignition plug (2) for generating a spark discharge for igniting an air-fuel mixture in a combustion chamber; an ignition coil (1) for supplying a high voltage to cause the ignition plug (2) to generate the spark discharge; and an ECU (3) for feeding a driving signal for driving the ignition coil (1). An electromotive force (secondary voltage) due to electromagnetic induction when a primary current is caused to flow through a primary winding of the ignition coil (1) in response to the driving signal from the ECU (3) is applied to the ignition plug (2) to detect an ion current generated in the combustion chamber to detect a combustion state in the ignition plug based thereon.

Abstract: An internal-combustion-engine combustion condition detection apparatus is provided with an ignition means that makes an ignition plug ignite a fuel; an ignition control means that controls the operation of the ignition means; an ion-current detection means that detects an ion current generated; an ion current detection range setting means that sets an ion-current detection range; a preignition detection means that detects preignition within a detection range to be set; a leakage current detection range setting means that sets a leakage-current detection range; and a leakage current determination means that determines whether or not a smolder exists, based on a current detected, within a detection range to be set, by the ion-current detection means. The ignition control means includes a non-combustion-stroke ignition control means; the leakage-current detection range set by the leakage current detection range setting means is set within the non-combustion stroke.

Abstract: An internal-combustion-engine combustion condition detection apparatus is provided with an ignition means that makes an ignition plug ignite a fuel; an ignition control means that controls the operation of the ignition means; an ion-current detection means that detects an ion current generated; an ion current detection range setting means that sets an ion-current detection range; a preignition detection means that detects preignition within a detection range to be set; a leakage current detection range setting means that sets a leakage-current detection range; and a leakage current determination means that determines whether or not a smolder exists, based on a current detected, within a detection range to be set, by the ion-current detection means. The ignition control means includes a non-combustion-stroke ignition control means; the leakage-current detection range set by the leakage current detection range setting means is set within the non-combustion stroke.