| 摘要 |
<p>The butterfly body, which can be used in an injection device, includes a casing (10) in which an intake port (18) is formed, and a butterfly (12) mounted on a median shaft (14) for rotation transverse to the port and which can be moved between a minimum open position and a maximum open position. The port has a wall of complex shape, so that the passage section offered to the air increases at the beginning of opening much more quickly than in the case of a cylindrical port. The port exhibits a cylindrical length (26) extending upstream and downstream of the minimum open position, and exhibits, upstream and downstream of the cylindrical length and along the path followed by the upstream and downstream edges of the butterfly until the latter is open by a given amount, respective zones delimited by circular arcs centred on the axis of the intake port and of radius decreasing from the cylindrical length. <IMAGE></p> |
