| 摘要 |
PURPOSE:To improve the accuracy of ignition timing by a method wherein the axial center of the ignition device is made movable with respect to the cam shaft of the engine to reduce a clearance between both gears for driving the engine and the ignition device in case the ignition device is attached to the engine. CONSTITUTION:In a support 7, the center of the inner diameter d1 of an inserting hole 7c, into which the boss section 6a of a housing 6 is inserted, and the center of the outer diameter d2 of the inserting boss 7d, inserted into an engine case 4, are not coaxial and are formed so as to be eccentric. By utilizing the eccentricity of the support 7, the clearance e2 between the cam shaft gear 2 of the engine and the driving gear 3 of the ignition device, which is determined individually in depending on the combination of these parts, may be reduced after attaching the ignition device to the engine. Accordingly, the fluctuation of ignition timing may be restricted by reducing said clearance even in case the fluctuation of rotation of the cam shaft 1 is caused and whereby the ignition device, matching with the engine and having the high accuracy of ignition timing, may be obtained. |
