Exhaust catalyst for outboard motor engine
AssigneeYamaha Marine Kabushiki Kaisha
InventorMasahiko Kato
Life of this patent
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Abstract
An exhaust catalyst assembly for an outboard motor includes a branched passage connecting the main exhaust passages with a catalyst device. The outboard motor can include various exhaust passages and features for controlling and discharging the flow to and from the catalyst device.
Claims23
An outboard motor comprising an internal combustion engine and a propulsion unit driven by the engine, the engine including an engine body defining a plurality of combustion chambers therein, and an exhaust system comprising an exhaust manifold defining a plurality of exhaust runners communicating with the combustion chambers, a merging portion in which the exhaust runners merge, and a common exhaust passage which receives exhaust gases from the merging portion, the common exhaust passage communicating with an expansion chamber configured to quiet exhaust noises traveling through the common exhaust passage, a valve disposed in the common exhaust passage and controlling a flow of exhaust gases therethrough, a catalytic treatment passage branched from the common exhaust passage at a position upstream from the valve, the catalytic treatment passage extending from the common exhaust passage to a catalytic treatment device so as to guide exhaust gases from the common exhaust passage upstream from the valve into the catalytic device, a throttle device configured to control the flow of air into the combustion chambers, a linkage arrangement connecting the throttle device to the valve so as to control movement of the valve proportionally to a movement of the throttle device, the linkage arrangement being configured to bias the valve to a closed position when the throttle device is in a position corresponding to an idle speed of the engine.
An outboard motor comprising an internal combustion engine driving a propulsion device, the internal combustion engine comprising an engine body defining at least one combustion chamber and an exhaust manifold configured to guide exhaust gases from the combustion chamber to an exterior of the engine body, a main exhaust passage extending from the exhaust manifold, the main exhaust passage including an outlet end communicating with an expansion chamber, a branched exhaust passage extending from the main exhaust passage at a position upstream from the outlet end, and a catalytic device, the branched passage connecting the catalytic device with the main exhaust passage, and the catalytic device not being within either of the main exhaust passage or expansion chamber.
An outboard motor comprising an internal combustion engine driving a propulsion device, the engine including an engine body defining at least one combustion chamber therein, and an exhaust system comprising a main exhaust passage and an expansion chamber, the main exhaust passage including an inlet end communicating with the combustion chamber and an outlet end communicating with the expansion chamber, an exhaust guide plate supporting the engine above the expansion chamber, the main exhaust passage extending through the exhaust guide plate, and an exhaust valve supported by the exhaust guide plate and configured to control a flow of exhaust gases through the main exhaust passage.
Dependencies are inferred from the claim text.