| 摘要 |
<p>PURPOSE:To make a coil body small without deteriorating magnetic characteristics of the iron core of an ignition coil for an internal combusion engine. CONSTITUTION:In the iron core of an ignition coil for an internal combustion engine which coil is provided with a T-shaped center core 10 wherein a primary coil 2 and a secondary coil 4 are wound around the outer periphery, an U-shaped outer peripheral core 12 which forms a closed magnetic path by sandwiching both ends of the center core 10 by facing surfaces formed in almost U-shapes, and a permanent magnet 14 arranged between the end portion 10a of the center core 10 and the outer peripheral core 12, said outer peripheral core 12 is flattened according to the ratio of the sectional area SM of the permanent magnet 14 to the sectional area SF of the central part 10b of the center core 10. Hence the sectional area of the core 12 is made nearly equal to the central part 10b of the center core 10, and the sectional shape is made wider and thinner than the central part 10b of the center core 10. As the result, the outer peripheral core is prevented from largely protruding from the coil body of an ignition coil, and miniaturization of the ignition coil can be realized.</p> |
