| 摘要 |
<p>PROBLEM TO BE SOLVED: To always and accurately detect ionic current varing according to the operating state of an internal combustion engine in the all driving ranges, in a full transistor-type ignition device. SOLUTION: The inductance of a secondary winding of an ignition coil is set in the range of 4 to 16H lower than the conventional one (20 to 30H) to shorten the duration of spark discharge in spark-discharging of an ignition plug by electrification and shutting to a primary winding and the voltage fluctuation time of the secondary winding to be generated in finishing of spark discharge. As a result, the time from the time when spark discharge is started to the time when ionic current corresponding to the ion amount generated with combustion of mixture can be detected is shortened, and the ionic current can be accurately detected. Since the duration of spark discharge is shortened and the ignitability of mixture is deteriorated if the inductance of the secondary winding is reduced, misfire judgment is performed (at the time t3) from the ionic current after the first spark discharge (at the time t1). In misfire, spark discharge is again performed by shutting of electrification to the primary winding. As a result, ignitability of mixture can be secured.</p> |
