| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent generation of cracking by relaxing thermal stresses between a primary coil bobbin and a portion of the casting resin located around the circumference of the bobbin, and to prevent invasion of water into the inside from a protruded portion of the coil unit from the casting face of the resin. SOLUTION: This ignition coil device for an engine is so constituted that a coil unit is housed in a coil case, wherein, in the coil unit, a rod-shaped core is inserted into the inside of a hollow shaft of a primary coil bobbin, while a secondary coil bobbin is coaxially engaged with the outside of the primary coil bobbin. The coil case is filled with an insulating casting resin for integral molding. A cap is prepared, which covers a protruded portion of the coil unit from the casting face of the resin, while a structure is adopted in which the skirt of the cap is buried in the casting resin. The primary coil bobbin is formed with a material whose adhesion to the casting resin is poor, while the cap is formed with a material whose adhesion to the casting resin is satisfactory.</p> |
