| 摘要 |
<p>The invention concerns a tailpipe wherein the thrust device comprises a valve body (20) including a chamber (24) partially enclosing the needle, at least a gas intake (27) opening into the chamber, and a gas outlet (25) emerging into the chamber and delimited by a wall portion which defines with a nozzle (14) part of a mobile needle (10) a gas exhaust section from the chamber. Actuating means (40, 41, 43) control the needle position in the valve body by acting on a rear part of the needle. The mobile needle (10) nozzle (14) has an aerodynamic concave profile (15) and the wall portion (29) delimiting the chamber outlet (25) is shaped for directing the exhaust gases substantially towards the needle nozzle concave part, which acts as main element for picking up thrust.</p> |
