| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an ignition coil for an internal combustion engine which is equipped with a central core having high bonding strength and can be manufactured with high precision. <P>SOLUTION: The ignition coil for internal combustion engine is inserted with a central core 14 which is integrated by laminating a plurality of steel plates 23 and deforming a part thereof plastically. The plurality of steel plates 23, ..., 23 are sectioned into a lowermost layer steel plate 23a including cut portions 24 formed at the opposite ends in the length direction and a plurality of punched portions 26 formed at equal intervals, and a plurality of laminated steel plates 23b-23k laminated on the lowermost layer steel plate 23a. The laminated steel plates 23b-23k include cut portions formed at the same positions as those of the cut portions of the lowermost layer steel plate 23a, and deformed recesses 25 formed at the same positions as those of the punched portions of the lowermost layer steel plate 23a. The deformed recess 25 has a rectangle in a plan view and a substantially V-shape in a plan view before plastic deformation and its length a is set at a predetermined value in correspondence with the thickness t of the steel plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
