MANUFACTURE OF IGNITION COIL

摘要

PURPOSE:To reduce the volume of a core, and to miniaturize and lighten an ignition coil by incorporating a permanently magnetizable magnetic material to one part of the core and generating magnetic flux in the direction opposite to magnetic flux generated by a primary coil through magnetization. CONSTITUTION:A plate 32 composed of a magnetic material for a permanent magnet is inserted to an air gap section 26 between the end sections of the main body section 10a of a core and an inserting section 10b. A primary coil 14 and a secondary coil 18 are mounted onto bobbins 12, 16, and housed in a housing 20, and a core body section 10a is inserted from one side of a bore in the bobbin 12 and the inserting section 10b is fitted and unified through a mating section 24 on the outside of the bobbin. A power supply 34 for magnetization is connected temporarily to the primary coil, and the magnetic material plate 32 is permanently magnetized. The polarity of the power supply 34 for magnetization is reversed to a normal battery power 40. Magnetic flux PHIm (b) is generated in the direction opposite to magnetic flux PHIc (a) generated by conducting the primary coil 14 when an ignition coil is used. Lastly, the power supply 34 for magnetization is detached from a circuit. Rare earth and iron groups such as samarium, cobalt, etc., are desirable as a blank for the magnetic material plate 32.