JPS6466913A - Ignition coil - Google Patents

Abstract

PURPOSE:To increase magnetic energy capable of being extracted from a core, to reduce the sectional area of the core and to miniaturize and lighten ignition coil itself by previously generating magnetic flux in the direction opposite to magnetic flux generated by conducting a primary coil when the magnetic flux is generated by conducting the primary coil. CONSTITUTION:A permanent magnet 32 is arranged in an air gap section 26 between the end sections of the main body section 10a of a core and an inserting section 10b as a flux generating means. When a primary coil 14 wound on the core 10 is supplied with supply voltage from a battery 40 and currents are interrupted by a switch 42 consisting of a contact-point or an igniter or the like, high voltage is generated in a secondary coil 19, and a spark is generated in a discharge section 44. Magnetic flux PHIm is generated by the permanent magnet in the direction (b) opposite to the direction of generation (a) of the magnetic flux PHIc of the primary coil generated by connecting the switch 42 by inserting the permanent magnet 32 to the core 10. The core 10 generates magnetic flux PHIc in the positive direction while receiving magnetic flux -PHIm in the negative direction, thus generating the variation of the magnetic flux of PHIc-(-PHIm)=PHIc+PHIm, then making the variation of magnetic flux larger than conventional devices only by PHIm.