| 摘要 |
PURPOSE:To secure a proper pulse signal all the time as well as to make accurate ignition timing controllable, by setting up a lot of concave and convex parts in a crankshaft at regular intervals, while securing the pulse signal which controls the ignition timing with a pulse pickup installed face-to-face to these concave and convex parts. CONSTITUTION:A crank gear 14 is formed in a crank wave installed in a crankshaft 5 being rotatably supported on a crankcase 1 via a bearing, while a clutch gear (unillustrated herein), transmitting turning force to a clutch mechanism, is engaged with the said gear 14. A pulse pickup 18 is installed in a position opposed to a lot of concave and convex parts comprising teeth 14a of the crank gear 14 at the specified interval, and fitted in a through hole 19 of the crankcase 1 and locked therein. Then, a pulse signal is generated by a voltage variation at a time when the said concave and convex parts pass through a pole piece 18b of the pickup 18, and according to this pulse signal, ignition timing control over an ignitor 21 is made to be done via an electronic ignition timing control unit 20. |
