| 摘要 |
A valve operating system includes: a decompression cam member (47); an exhaust gas recirculation cam member (48) that is provided on the camshaft (26), and moves between an inoperative position (F) where the exhaust tappet (27e) is released and an operative position (G) where the exhaust tappet (27e) is operated in a valve opening direction in an intake stroke of the engine (1); and a common centrifugal mechanism that is driven by the camshaft (26) to operate the decompression cam member (47) to the operative position (C) in a starting rotation region of the engine (1) and to the inoperative position (D) after the starting, and operate the exhaust gas recirculation cam member (48) to the inoperative position (F) in a low speed operation region of the engine (1) and to the operative position (G) in a high speed operation region. Thus, the valve operating system can exert both a decompression function and an exhaust gas recirculation function. |
