Crankcase ventilation system for outboard motor
AssigneeSanshin Kogyo Kabushiki Kaisha
InventorsHiroshi Nakai, Akihiko Hoshiba, Yasuhiko Shibata
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Abstract
A ventilation system is provided for an engine crankcase of a marine outboard motor to distribute blow-by gas generally equally to each cylinder while minimizing the size of an intake silencer of the system. The intake silencer includes a first expansion chamber into which the blow-by gas is introduced from a blow-by gas camber attached to the cylinder head. The blow-by gas diffuses and mixes with ambient air which is drawn into the first expansion chamber through an inlet port of the induction system. The air/blow-by gas mixture is then drawn into a second expansion chamber where it distributes generally evenly before induction into a charge forming device.
Claims19
A ventilation system for a crankcase of an internal combustion engine comprising an intake silencer including a unitary housing having at least first and second expansion chambers in communication with each other and separated by a wall which is common to both said first and second expansion chambers, said first and second expansion chambers being arranged so that ambient air flows into said first expansion chamber before flowing into said second expansion chamber, and an induction conduit in communication with said crankcase to vent blow-by gas from said crankcase, said conduit extending between said engine and said first expansion chamber so as to direct blow-by gas into said first expansion chamber of said intake silencer.
A ventilation system for a crankcase of an internal combustion engine of a marine drive, said ventilation system connected to an intake system comprising a plurality of induction conduits going to a plurality of intake pipes of said engine, said ventilation system comprising a blow-by gas chamber provided on said engine to collect blow-by gas, and an intake silencer commonly connected to said plurality of induction conduits, said intake silencer including multiple expansion chambers, a first expansion chamber being arranged to receive a flow of ambient air and being connected to said blow-by gas chamber in a manner directing blow-by gas into said first expansion chamber for mixture with said ambient air, and a second expansion chamber in communication with said first expansion chamber, said first and second expansion chambers being formed within a unitary housing of the said intake silencer and being divided by a wall within the housing which is common to both said first and second expansion chambers, said wall defining at least an aperture for fluidic communications between first and second expansion chambers.
Dependencies are inferred from the claim text.