| 摘要 |
<p>PURPOSE:To make a magnetic characteristic of this ignition coil good and to make the ignition coil small-sized and lightweight by a method wherein a low-voltage input coil is pulse-driven at a duty of 20% or less and a core has a saturated magnetic flux density exceeding a specific value and is used within a specific range of a maximum flux density. CONSTITUTION:Cores 1, 2 are formed to be C-shaped or U-shaped; mutual end faces are brought face to face with each other via magnetic gaps 11, 12. If the cores 1, 2 of a good magnetic characteristic having a saturated magnetic flux density Bs exceeding a maximum magnetic flux density Bm is used within a range of the maximum magnetic flux density Bm=1.2-1.5 tesla, it is possible to reduce a size of the cores by 20-50%. Because a low-voltage input coil 3 is pulse-driven at a duty of 20% or less by using a fully transistorized drive circuit, it is possible to prevent heat from being generated at the cores. If an effective relative permeability value Xs in a magnetic route due to the magnetic gaps 11, 12 is adjusted to a range of 100-300, an inductance value of the coil can be set to an appropriate value; ignition energy, transmission efficiency and a discharge duration can be set to optimum values.</p> |
