| 摘要 |
<p>An engine includes an exhaust system having an exhaust passage for guiding exhaust gas discharged from a combustion chamber and an air supply system for supplying air. The exhaust passage is provided with a convergent portion, a divergent portion, and a branch portion. The branch portion divides a shock wave, which is propagating through the exhaust passage toward the downstream side, from the exhaust passage upstream of the divergent portion, and allows the shock wave to again propagate through the exhaust passage. The air supply system includes a first passage that is provided with a first reed valve through which an airflow running from an upstream end toward a downstream end passes and that has its downstream end connected to the exhaust passage located upstream of the divergent portion, and a second path that has its upstream end connected to the first passage located downstream of the first reed valve. The exhaust system is arranged to allow the exhaust gas to pass through the convergent portion and to collide, between the branch portion and the divergent portion, with a shock wave that has propagated through the branch portion.</p> |
