Noise reducing device for marine propulsion
AssigneeSanshin Kogyo Kabushiki Kaisha
InventorsHiroaki Outani, Seiji Inoue
Life of this patent
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Abstract
A number of embodiments of silencing devices for marine propulsion units using acoustical lenses that are positioned across either the air inlet device, the air exhaust device or both. The acoustical lenses direct the sound waves in such a way so as to effect silencing while, at the same time, ensuring that water will not enter the engine combustion chambers. The invention is shown in conjunction with both outboard motors and inboard mounted engines.
Claims21
In a marine propulsion unit comprised of an internal combustion engine having an output shaft, a marine propulsion device driven by said engine output shaft, said engine having an induction system comprised of an atmospheric air inlet device for delivering an air charge to said engine for combustion, and an exhaust system having an exhaust outlet device for discharging exhaust gases from said engine to the atmosphere, the improvement comprising an acoustical lens extending at least in part across at least one of said devices for silencing sound waves emanating therefrom.
Dependencies are inferred from the claim text.