| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To easily and surely prevent a permanent magnet fixed to a magnet core of an ignition coil from deteriorating. <P>SOLUTION: A primary coil that is wound around the outer periphery of the magnet core to send a primary current, a secondary coil in which a secondary voltage is generated by energizing/shutting off the primary current, and the permanent magnet that is fixed to one end of the magnet core to magnetize it in a direction reverse to the magnetization direction of the primary current energizing, are comprised. The magnet core is magnetically saturated with a primary current value at shutting-off. A ratio between an stress area of the magnetic core and a fixing area of the permanent magnet is so set that a magnetic field generated in the permanent magnet is smaller than a demagnetization limit magnetic field of the permanent magnet. <P>COPYRIGHT: (C)2003,JPO</p> |
