| 摘要 |
<p>PURPOSE:To form an optimum passage shape at a low cost by attaching a straightening vane for straightening intake air emitted out of an intake window, to a housing at the rear of a stopper attached to the back of a valve element in a reed valve. CONSTITUTION:When a piston goes down, a reed valve 5 is closed. That is, a valve element 5b takes a valve seat surface 5a, closing an intake window 5a3, and thereby the inner part of a crankcase 3b is precompressed. Therefore, intake air in this precompressed crankcase 3b is scavenged to a combustion chamber from a scavenging passage 2e. Incidentally, if up-and-down differential pressure in this valve element 5b becomes higher than the specified value, its base end is lifted up after the tip is separated from the valve seat surface 5a2, and thereby the back comes into contact with a stopper 5c. At this time, at the initial stage of strokes of the valve element 5b, the intake air is conducted into an inlet passage 3c as guiding it with the tip of a straightening vane 5d. At both the middle and latter stages of strokes of the valve element, the intake air is taken into the crankcase 3b as guiding it with a wall surface of the straightening vane 5d.</p> |
