| 摘要 |
<p>In an engine in which a valve actuating mechanism is driven through a timing chain 31 by means of a chain drive sprocket 28 mounted on a crank shaft 6, a guide boss 33 is disposed adjacent to the chain drive sprocket 28 and the guide boss 33 is provided with an inclination surface 33a inclined downward toward an outer peripheral edge 28a of the chain drive sprocket 28. An auxiliary mechanism driving gear 32 is mounted on the crank shaft 6 adjacent to the chain drive sprocket 28 and the guide boss 33 is formed integrally with a side surface of the auxiliary mechanism driving gear 32 on the side of the chain drive sprocket 28. <MATH></p> |
