| 摘要 |
<p>PURPOSE: To improve the airtightness of an inner space of a rubber cap without deteriorating the workability of rubber cap pressure fitting by providing grooves not reaching an opening end at deep positions having a predetermined distance from the opening end on the inner peripheral surface of a cylindrical portion pressure-fitted to the outer peripheral surface of an insulator portion of an ignition plug. CONSTITUTION: An output electrode 12 is housed within an axial portion 11 of a resin housing 10 of an ignition coil 1, one end portion of a cylindrical rubber cap 2 is fitted to a tip portion of the axial portion 11, and a base end portion 31 of an ignition plug 3 made of an insulator is fitted to other end portion of the rubber cap 2. While the rubber cap 2 is being pressure-fitted to the base end portion 31 of the ignition plug 3, many tiny cup-shaped grooves 4 are formed at a portion 21 on the inner peripheral surface of the rubber cap 2 tightly came into contact with the outer peripheral surface of the base end portion 31, and the inner spaces of the grooves 4 are filled with talc. As stated above, the grooves 4 of the rubber cap 2 are arranged at the position not reaching the opening end. By doing this, the workability of the pressure- fitting (attaching and detaching) of the rubber cap 2 can be made much easier.</p> |
