| 摘要 |
<p>A valve drive mechanism includes a tappet assembly (24) which comprises a centre tappet (43), a pair of side tappets (41, 42) between which the centre tappet (43) is interposed so as to move relatively to the side tappets (41, 42), and a locking/unlocking mechanism (200) operative to mechanically couple the centre tappet (43) to both of the side tappets (41, 42) and to uncouple the centre tappet from both of the side tappets (41, 42) so as to selectively transmit rotation of a high lift centre cam (26) and low lift side cams (25, 27) to twin valves such as twin intake valves (39) and twin exhaust valves (49) per cylinder (A). Locking/unlocking of the centre tappet (43) and each side tappet (4i, 42) is performed in a position which is in a vertical plane including a centre axis (L1, L2) of each side tappet (41, 42) and intersecting perpendicularly to an axial direction of a camshaft (15, 16) and is offset from the centre axis (L1, L2) of the side tappet (41, 42).</p> |
