Abstract: According to one embodiment, an internal combustion engine ignition system, including: a plurality of spark coils each having a primary coil and a secondary coil, each secondary coil being coupled to a common spark plug to apply a high voltage thereto; a plurality of primary current generation module provided correspondingly with the spark coils and configured to asynchronously generate primary currents respectively flowing through the primary coils; one or a plurality of primary current detection module configured to detect each of the primary currents; and a primary current control module configured to adjust an output power supplied to each primary coil in accordance with a change in the primary current to thereby control an increase rate of the primary current.

Abstract: According to one embodiment, there is provided an internal combustion engine ignition system, including: a spark coil having primary and secondary coils, the spark coil being configured to apply a high voltage to a spark plug from the secondary coil; a power transistor configured to perform an intermittent control on a current flowing through the primary current for a given time period, based on an inputted multipulse; a DC-DC converter electrically connected to the primary coil and configured to control a bias voltage applied to the primary coil; and a converter control circuit configured to control the DC-DC converter while switching a control mode to either a feedback mode in which the bias voltage is increased or decreased based on a detection value of the bias voltage, or a forced voltage increase mode in which the bias voltage is forcedly increased.

Abstract: Provided is a method for determining a combustion state of a spark-ignited internal combustion engine including an ignition plug to ignite a fuel-air mixture by a plasma generated by a reaction between a spark discharge generated by a high voltage applied through an ignition coil connected to the ignition plug and an electric field generated in a combustion chamber. In the method, a change in a secondary voltage secondarily generated in the ignition plug after the spark discharge in association with the spark discharge is detected. A case where the change in the detected secondary voltage deviates from a predetermined range is determined as an occurrence of misfire. This enables detection of a misfire state without being hindered from an ion current due to the plasma remaining in the combustion chamber.

Abstract: According to one embodiment, an internal combustion engine ignition system, including: a plurality of spark coils each having a primary coil and a secondary coil, each secondary coil being coupled to a common spark plug to apply a high voltage thereto; a plurality of primary current generation module provided correspondingly with the spark coils and configured to asynchronously generate primary currents respectively flowing through the primary coils; one or a plurality of primary current detection module configured to detect each of the primary currents; and a primary current control module configured to adjust an output power supplied to each primary coil in accordance with a change in the primary current to thereby control an increase rate of the primary current.

Abstract: The present invention is an operation control method on the basis of an ion current in an internal combustion engine, the method comprising a step of detecting the ion current generated within a combustion chamber 30 so as to control an operating state of the internal combustion engine 100 on the basis of a state of the detected ion current, wherein a control at an engine start point in time on the basis of the state of the ion current is stopped for predetermined cycles just after the engine start.

Abstract: An ion current detecting apparatus includes a capacitor C that is charged as a spark plug 3 discharges, a Zener diode ZD that limits a maximum voltage of the capacitor C while charging, a detection resistor R2 through which a discharge current of the capacitor C flows, and a comparator circuit 5 that compares a current value of the detection resistor R2 with a predetermined value. A charge quantity Q of the capacitor C at discharge start is set so that, as a consequence of a discharging operation of the capacitor C, discharge duration required until the current value of the detection resistor R2 falls below the predetermined value becomes longer than time duration in which the ion current generated by fuel combustion in the engine combustion chamber lasts. The ion current detecting apparatus automatically detects degradation in an insulation resistance in the spark plug, ensuring normal operation in engine control.

Abstract: The present invention is an operation control method on the basis of an ion current in an internal combustion engine, the method comprising a step of detecting the ion current generated within a combustion chamber 30 so as to control an operating state of the internal combustion engine 100 on the basis of a state of the detected ion current, wherein a control at an engine start point in time on the basis of the state of the ion current is stopped for predetermined cycles just after the engine start.

Abstract: The invention relates of a method for determining a combustion state of an internal combustion engine, for detecting an ion current generated within a combustion chamber of the internal combustion engine, including the steps of measuring a characteristic value of the ion current detected during a period that the ion current is generated and a generation period in which the ion current is generated, and determining a combustion state on the basis of a relation between the characteristic value and the generation period with respect to an elapsed time from an ignition, and the method comprises determining that the combustion state is normal, by setting a determination reference to be larger with respect to the characteristic value and shorter with respect to the generation period, in the case that the elapsed time from the ignition is short, and determining that the combustion is normal, by setting the determination reference to be smaller with respect to the characteristic value and longer with respect to the g

Abstract: An ion current detecting apparatus includes a capacitor C that is charged as a spark plug 3 discharges, a Zener diode ZD that limits a maximum voltage of the capacitor C while charging, a detection resistor R2 through which a discharge current of the capacitor C flows, and a comparator circuit 5 that compares a current value of the detection resistor R2 with a predetermined value. A charge quantity Q of the capacitor C at discharge start is set so that, as a consequence of a discharging operation of the capacitor C, discharge duration required until the current value of the detection resistor R2 falls below the predetermined value becomes longer than time duration in which the ion current generated by fuel combustion in the engine combustion chamber lasts. The ion current detecting apparatus according to the present invention quickly and automatically detects degradation in an insulation resistor in the spark plug to ensure a normal operation in engine control.

Abstract: The arrangement for mounting a sparkplug of an internal combustion engine includes mounting the sparkplug so that all of the outside electrodes are arranged at an intake port side area and/or an exhaust port side area. Alternatively, in the case where at least one of the outside electrodes is located outside of the above-mentioned areas, no other remaining outside electrodes are arranged at a position that faces that outside electrode across the central electrode.

Abstract: There is provided an improved method of detecting an occurrence of a knock in an internal combustion engine by detecting an ionic current flowing in a cylinder of the engine from initiation of combustion therein and judging a knock component overlapping the ionic current based on a judging level, the method including the steps of: detecting a peak value of the ionic current; and relatively correcting at least one of the judging level and the knock component based on the peak value thus detected so as to make more difficult a judgment of whether the knock occurs or not as the detected peak value increases.

Abstract: The arrangement for mounting a sparkplug of an internal combustion engine in accordance with the present claimed invention is that the sparkplug is mounted so that all of the outside electrodes are arranged in areas of a side of an intake port opening and/or a side of an exhaust port opening limited by the sparkplug and the intake port opening and by the sparkplug and the exhaust port opening or in case at least one of the outside electrodes locates outside of the above-mentioned limited area, other remaining outside electrodes are arranged at positions to avoid facing the outside electrode locating outside of the limited area across the central electrode.

Abstract: There is provided an improved method of detecting an occurrence of a knock in an internal combustion engine by detecting an ionic current flowing in a cylinder of the engine from initiation of combustion therein and judging a knock component overlapping the ionic current based on a judging level, the method including the steps of: detecting a peak value of the ionic current; and relatively correcting at least one of the judging level and the knock component based on the peak value thus detected so as to make more difficult a judgment of whether the knock occurs or not as the detected peak value increases.