| 摘要 |
<p>PURPOSE:To enhance a punching yield by a method wherein a core is assembled in such a way that a closed magnetic circuit is constituted by a first J-shaped core part and a second J-shaped core part whose shapes are nearly identical to each other. CONSTITUTION:If a primary electric current flowing to a primary coil 2 is broken, an ignition pulse voltage of a high voltage is induced in a secondary coil 3 and is output from a high-voltage tower 33. Because a first main side part 111 and a first auxiliary side part 121 are inserted into a thin tube part 41, a first core 11 and a second core 12 are coupled strongly to a coil case 4. J-shaped silicon steel sheets 101, 102 of an identical shape which constitute the primary core 11 and the secondary core 12 are stamped from a band steel sheet 100. A stamping die is formed in such a way that an auxiliary side part 104 of the J-shaped silicon steel sheet 102 comes close to a recessed part 103 of the J-shaped silicon steel sheet 101. A length D of side parts 107, 108 of the J-shaped silicon steel sheets 101, 102 is set to be approximately equal to a width of auxiliary side parts 104, 105; a length A of a main side part 106 is set to be approximately equal to a sum of a length B of the auxiliary side parts 104, 105 and a width C of the side parts 107, 108. By this setup, the J-shaped silicon steel sheets can be stamped out at a high yield.</p> |
