Acoustic diverter for an idle air bypass valve passage

摘要

An arrangement for reducing noise produced by an engine idle air bypass passage 20 and valve. The idle air passage 20 has an inlet to receive air from the air intake duct and an outlet coupled to the manifold of the engine. The noise reduction arrangement comprises an acoustic diverter 22 placed at the outlet of the air bypass passage 20, arranged to limit sound waves generated by the air flowing through the passage from travelling directly towards exterior walls of the manifold as they exit the passage. The acoustic diverter 22 may be contoured relative to the flow of the air exiting the bypass passage so that the waves are redirected to an inner portion of the engine.