Yamaha Hatsudoki Kabushiki Kaisha

Koichi Nakayama

Katsumi Ochiai

Toshio Suzuki

Shinya Maekawa

Yukinori Nose

Shinya Kasai

Naoki Kinomoto

Makoto Morino

Jiro Fukuoka

An outboard motor includes an engine, a relay exhaust pipe, a downstream exhaust pipe connected to the relay exhaust pipe, and a propeller to be driven by the engine. The engine includes a plurality of cylinders arranged in series along a vertical direction, a plurality of exhaust ports respectively extending from the combustion chambers of the plurality of cylinders in a sideward direction, and an upstream exhaust pipe connected to the plurality of exhaust ports and extending downwardly. A lower end portion of the upstream exhaust pipe is connected to the relay exhaust pipe from above. The upstream exhaust pipe includes an upstream portion located at a higher location than the lower end portion and extending linearly downwardly. The lower end portion is located closer to the combustion chamber than the upstream portion with respect to a left-right direction.

Outboard motor

A vessel propulsion apparatus includes an engine and a propulsion unit to be driven by the engine. The engine includes cylinders arranged in series, exhaust ports respectively connected to combustion chambers of the cylinders and curved in a predetermined downstream direction to allow exhaust gases to flow out from the combustion chambers, and a collecting exhaust pipe. The collecting exhaust pipe is integral with the exhaust ports, and extends in the downstream direction to allow exhaust gases in the exhaust ports to flow in the downstream direction. At least one of a plurality of connector portions that individually connect the exhaust ports to the collecting exhaust pipe includes a concave portion at an inner surface thereof.

Vessel propulsion apparatus, vessel, vessel engine, and exhaust structure of vessel engine

An outboard motor includes an engine, a pressure charger, an intercooler, a bypass air passage, and an air bypass valve to open and close the bypass air passage. The engine includes a cylinder block and an air intake passage and an exhaust passage both of which are connected to the cylinder block. The pressure charger is located in the air intake passage. The intercooler is located in the air intake passage between the cylinder block and the pressure charger. A first end of the bypass air passage is connected to a region of the air intake passage upstream of the pressure charger. A second end of the bypass air passage is connected to a region of the air intake passage downstream of the pressure charger. The air bypass valve is directly attached to the intercooler.

Outboard motor and vessel

A watercraft propulsion system includes a propulsion unit to be driven by an engine. The engine includes a cylinder block, an air intake channel, an exhaust channel, a supercharging device, and a fuel injector. The watercraft propulsion system includes the engine, the propulsion unit to be driven by the engine, a rotation speed sensor to detect a rotation speed of the engine, an air intake pressure sensor to detect an air intake pressure of the engine, and a controller. The controller is configured or programmed to compute a command fuel injection amount so that the engine performs a combustion operation at an air/fuel ratio in a lean-burn range (lean-combustion range) according to the rotation speed detected by the rotation speed sensor and the air intake pressure detected by the air intake pressure sensor, and to drive the fuel injector based on the computed command fuel injection amount.

Watercraft propulsion system and watercraft including the watercraft propulsion system

An outboard includes a plurality of first branched pipes connected to a plurality of first exhaust ports and a plurality of second branched pipes connected to a plurality of second exhaust ports, respectively, wherein the plurality of first branched pipes are connected to a first collecting pipe and the plurality of second branched pipes are connected to a second collecting pipe. A connector connects the first collecting pipe and the second collecting pipe. The plurality of first branched pipes extend in a direction away from the connector in a plan view, and each includes a first exhaust pathway located farther away from the connector than the first collecting pipe is in the plan view. The plurality of second branched pipes extend in a direction away from the connector in a plan view, and each includes a second exhaust pathway located farther away from the connector than the second collecting pipe.

Outboard motor and engine mechanism

An engine includes a crankshaft. A driveshaft is connected to the crankshaft, and extends in an up-and-down direction of an outboard motor. A propeller shaft is connected to the driveshaft, and extends in a back-and-forth direction of the outboard motor. An intake pipe is connected to the engine. The intake pipe includes a first pipe portion and a second pipe portion that are provided separately from each other. A seal member is disposed between the first and second pipe portions, and couples the first and second pipe portions therethrough.

An intake manifold is connected to a cylinder of an engine, and extends backward from the cylinder. A throttle body is attached to the intake manifold. As seen in a plan view of an outboard motor, the throttle body is disposed backward of a head cover, while being disposed inward of a lateral end of the intake manifold in a right-and-left direction of the outboard motor.

An outboard motor includes an exhaust passage that discharges exhaust gases generated in a V-type engine into water from an exhaust opening. The exhaust passage includes first and second branch passages connected to cylinders and disposed inside a V-shaped line, a first upstream collecting passage connected to each of the first branch passages, a second upstream collecting passage connected to each of the second branch passages, and a downstream collecting passage connected to the first and second upstream collecting passages. A portion from an upstream end of the downstream collecting passage to a downstream end of the downstream collecting passage is disposed outside cylinder heads of the V-type engine.

An engine includes an exhaust sensor projecting from an opening in an inner surface of a first exhaust pipe to inside of an exhaust passage, and a projection provided in the inner surface of the first exhaust pipe along the opening, and positioned farther inside the exhaust passage than the opening, wherein at least a portion of the projection is positioned upstream of the opening in a flow direction of exhaust gases.

Engine and outboard motor

An engine includes a V-shaped cylinder body, first and second exhaust manifolds inside a V-shaped line, and an exhaust pipe. The exhaust pipe includes a first upstream end portion into which exhaust gases discharged from first cylinders to the first exhaust manifold flow, and a second upstream end portion into which exhaust gases discharged from second cylinders to the second exhaust manifold flow. A spiral wound gasket seals a gap between the first exhaust manifold and the first upstream end portion.

V-type engine

A fuel supply device that supplies fuel from an external tank to an engine includes a fuel injection, an internal tank, a first pipe, a second pipe, a first pump, a fuel supply quantity detection device, and a control device. The internal tank stores fuel to be delivered to the fuel injection device. The first pipe is linked to the internal tank and delivers fuel from the external tank to the internal tank. The second pipe is linked to the fuel injection device and delivers fuel from the internal tank to the fuel injection device. The fuel supply quantity detection device is attached to the first pipe and detects a quantity of fuel supplied from the external tank via the first pipe to the internal tank. The control device implements a predetermined control when the quantity of fuel detected by the fuel supply quantity detection device is below a threshold.

Fuel supply device and outboard motor

An engine includes an engine body and an exhaust pipe. The engine body includes a combustion chamber and an oil passage in which lubricating oil flows. The exhaust pipe includes an exhaust passage and an oil jacket. The exhaust passage is linked to the combustion chamber. The oil jacket is linked to the oil passage.

Engine

An exhaust pipe connecting structure includes a first exhaust pipe, a second exhaust pipe, a seal member, and a gasket. The second exhaust pipe is a separate part from the first exhaust pipe. The second exhaust pipe is connected to the first exhaust pipe and defines an exhaust passage together with the first exhaust pipe. The seal member is located between the first exhaust pipe and the second exhaust pipe in a connecting portion where the first exhaust pipe and the second exhaust pipe connect. The gasket is arranged between the seal member and the exhaust passage in the connecting portion where the first exhaust pipe and the second exhaust pipe connect together. The gasket has a heat resistant property.

Exhaust pipe connecting structure

A marine propulsion device includes an engine, an exhaust passage, a porous body, a retainer mat, and a stopper portion. The engine includes an exhaust port. The exhaust passage connects to the exhaust port. The porous body is disposed in the exhaust passage. The retainer mat covers the outside peripheral face of the porous body. The retainer mat retains the porous body. The stopper portion is disposed inside the exhaust passage. The stopper portion is disposed downstream of the porous body and spaced apart from a downstream-side end portion of the porous body. The stopper portion extends inwardly in the radial direction, past the outside peripheral surface of the porous body.

Growing community of inventors

Shizuoka, Japan

Koichi Nakayama