| 摘要 |
<p>PROBLEM TO BE SOLVED: To solve problems that, when a switching element of an ignition coil and an ion current detecting circuit are disposed inside of the ignitor, power source ripple is applied to a collector terminal of the ignitor and transferred to the ion current detecting circuit from a lead frame, and further a combustion state of an internal combustion engine cannot be accurately determined by using ion current, as the power source ripple is superposed to detected ion current waveform when the power source ripple is applied to the ion current detecting circuit.SOLUTION: An ignition coil includes: a coil portion in which a primary coil and a secondary coil are electromagnetically coupled; an ignitor including a switching element for supplying an ignition signal to the primary coil; and an ion current detecting circuit for detecting ion current generated between electrodes of an ignition plug for discharging high voltage from the secondary coil. The ignitor is provided with an ion current detecting circuit integrally sealed with the switching element with a resin. In the ignitor, the switching element and the ion current detecting circuit are arranged in a state of being electrically insulated from each other.</p> |
