| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an ignition coil with which a spring can be easily manufactured and which can effectively suppress the occurrence of a fine corona discharge to effectively suppress a decrease in spark voltage. <P>SOLUTION: The ignition coil 1 is constituted by coupling together a coil unit 11 formed by storing a primary coil 21 and a secondary coil 22 in a coil case 4 and a joint unit 5 for electrically connecting a high-voltage winding end of the secondary coil 22 to a spark plug. The ignition coil 1 is configured to have the joint unit 5 disposed in a plug hole provided to a metallic cylinder head and also to have the coil unit 11 disposed nearby an opening portion of the plug hole. The joint unit 5 has a joint case 51 made of a cylindrical resin and the spring 6 disposed in the joint case 51. The spring 6 is formed using a steel wire 60, and thinner at an intermediate portion 602 in its axial direction L than both end portions 601 in the axial direction L. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
