| 摘要 |
PROBLEM TO BE SOLVED: To provide an ignition coil having long service life by restraining the growth of a tree in a spool which is generated by discharge. SOLUTION: In this ignition coil, a primary spool 23 is arranged on the outer periphery of a secondary coil 21. The primary spool 23 uses PBT (polybutylene terephthalate) which has low melting viscosity and is superior in molding fluidity as a resin base material, and to the PBT, 5 wt.% of olefin rubber, 12.5 wt.% of glass fiber and 2.5 wt.% of silica are added, and the spool is formed. A primary coil 24 is formed by winding a winding in which PET (polyethylene terephthalate), silicone, wax, etc., are coated as separating member on the outer periphery of a wire, on the outer periphery of the primary spool 23. Since silica is added to the primary spool 23, the growth of a tree in the primary spool 23 is restrained, oven when discharge is generated between the secondary coil 21 of high potential and the primary coil 24 of low potential and corrosion is generated in the primary spool 23. |
