| 摘要 |
PURPOSE:To reduce the quantity of resin used and to lower inductance in the amount of the reduced resin by a method wherein, in the ignition coil for internal-combustion engine having a primary winding, a secondary winding and a center core, a notch is provided at the corner part of a core along the core when the winding part of the center core is resin-molded, and resin is filled up in this notch only. CONSTITUTION:A notch 1a is formed along longitudinal direction at the four corner parts of a center core having an almost rectangular cross-section, the resin 2 which is turned to a primary bobbin is filled in the notch, and a primary winding 3 is wound around the surface, including the notch 1a, and the exposed surface of the core 1. At this time, the extreme outer circumference of the winding part of the resin 2 is formed a little higher than the winding part of the center core, and a stepping G is generated thereon. Then, the outer circumference of the primary winding 3 is surrounded by a secondary bobbin 4 having the winding groove divided into a plurality of parts, and the secondary winding 4 is wound around the grooves. Then, the whole body is placed in a housing case 6, and the generated gap is filled up by molding resin 7. As a result, the amount of resin 2 used for a primary bobbin can be reduced, the inductance is lowered in the amount of resin reduced, and the efficiency of ignition can be improved. |
