Yamaha Marine Kabushiki Kaisha

Sanshin Kogyo Kabushiki Kaisha

Goichi Katayama

Masanori Takahashi

Kazuhiko Watanabe

Masaki Okazaki

Noriyoshi Hiraoka

Yoshibumi Iwata

Sadato Yoshida

Masashi Nonaka

Masahiko Kato

Isao Kanno

Katsumi Ochiai

Yoshikazu Nakayasu

Takaji Kawai

Hitoshi Ishida

A propulsion system for a watercraft includes an engine. An air intake device delivers air to a combustion chamber. A throttle valve regulates an amount of the air. A control device sets the throttle valve to a desired position. A remote controller provides the control device with the desired position. The engine can include an auxiliary intake device that delivers supplemental air to the combustion chamber. A control valve normally shuts the supplemental air from the combustion chamber. The control device determines whether an abnormal condition occurs in setting the throttle valve to the desired position. The control device determines whether the amount of the air is insufficient. The control device controls the control valve to allow the supplemental air to move to the combustion chamber when the control device determines that the abnormal condition occurs and the amount of the air is insufficient.

Watercraft propulsion system and control method of the system

An air intake system for an engine of an outboard motor includes an air intake support member that provides support for other components of the air intake system. The other component of the air intake system that can be supported by the air intake support member include a throttle valve assembly, plenum chambers, and air intake passages. The air intake passages can be made longer to increase engine performance and can be manufactured with less material because the air intake passages do not need to provide support for the air intake system.

Air intake structure for engine

An outboard has a housing unit mounted on an associated watercraft. An engine is disposed on the housing unit. A cowling surrounds the engine. The cowling has an inlet port through which atmospheric air enters inside of the cowling. At least a substantial portion of the cowling is made of a nonferrous metal.

Outboard motor with cowling

An air intake system for an engine of an outboard motor includes air intake plenum chambers and corresponding air intake passages. Residual condensed fuel that can accumulate in the plenum chamber is guided to lower air intake passages through a slot at a predetermined rate to be delivered to combustion chambers inside the engine. The air intake system can reduce the likelihood that the plenum chambers will accumulate residual fuel above an acceptable amount and can allow the residual fuel to be more slowly delivered to the engine so as to evacuate the fuel without substantially altering the desired air/fuel ratio.

Intake system for outboard engine

An internal combustion engine comprising an engine body. A combustion chamber is formed in the engine body and has at least one valve seat. A valve is configured to move between an open position and a closed position of the valve seat. A valve actuator is configured to actuate the valve. A variable valve timing mechanism is configured to change an actuating timing of the valve actuator at which the valve actuator actuates the valve. At least one sensor configured to sense and operational condition of the engine. A control device is configured to determine if the engine is operating in a cruising mode. The control device is also configured to reduce engine speed fluctuations during the cruising mode by adjusting the actuating timing of the valve actuator.

Control system for outboard motor

An engine has an engine body having an outer surface that defines an outer area next thereto. An air intake system has an intake valve movable between a closed position and an open position. An intake camshaft that actuates the intake valve extends through the engine body and toward the outer area beyond the outer surface. A drive mechanism drives the camshaft. A portion of the drive mechanism is disposed in the outer area. A hydraulically operated change mechanism changes an angular position of the camshaft relative to a crankshaft. A control valve unit controls the change mechanism. The control valve unit at least in part is disposed within the outer area.

Four-cycle engine

An outboard motor includes four-cycle engine for a marine drive, and more particularly a four-cycle engine for a marine drive that has a vertically extending camshaft. The four-cycle engine includes at least one pre-ignition or knock sensor. An electronic control unit adjusts ignition timing and intake camshaft timing to protect the engine during a pre-ignition condition while improving fuel efficiency and preserving high engine output.

Knocking avoidance control system of a four-stroke engine for an outboard motor

An engine for a marine drive has a combustion chamber. An engine body of the engine defines intake and exhaust ports communicating with the combustion chamber. An air induction system communicates with the combustion chamber through intake ports. An exhaust system communicates with the combustion chamber through the exhaust ports. Intake valves move between an opening position and a closing position of the intake ports. Exhaust valves move between an opening position and a closing position of the exhaust ports. Camshafts actuate the intake and the exhaust valves. A hydraulic VVT mechanism changes an actuating timing of the camshaft at which the camshaft actuates the intake valves or the exhaust valves. An ECU controls the VVT mechanism based upon a control characteristic. A temperature sensor, such as an oil temperature sensor, a water temperature sensor and an engine body temperature sensor, senses a temperature of oil of the VVT or a temperature relating to the temperature of the oil and sends a temperature signal to the ECU. The ECU adjusts the control characteristic when the temperature is lower than a preset temperature.

Valve timing control for marine engine

An engine for a marine drive has a combustion chamber. An engine body of the engine defines an air intake port communicating with the combustion chamber. An air induction device communicates with the air intake port to introduce air to the combustion chamber through the air intake port. The air induction device includes a throttle valve to regulate an amount of the air. An air intake valve moves between an opening position and a closing position of the intake port. A camshaft actuates the intake valve. A VVT mechanism changes an actuating timing of the camshaft at which the camshaft actuates the intake valve. A control device controls the change mechanism. A throttle position sensor, an intake pressure or other sensors sends respective signals to the control device. The control device determines a sudden acceleration state of the engine based upon at least one of the signals. The control device triggers the VVT mechanism to advance the actuating timing based only upon the throttle opening degree signal when the control device determines the sudden acceleration state.

An internal combustion engine for an outboard motor that comprises at least one combustion chamber formed by at least a engine body, a cylinder head assembly and a piston that moves relative to the engine body and the cylinder head assembly. A crankshaft extends in a generally vertical direction and is coupled to the piston such that movement of the piston causes the crankshaft to rotate. A camshaft is journaled for rotation and extends generally parallel to the crankshaft. The camshaft includes at least one cam configured to open and close a valve. A control valve for a variable valve timing mechanism is positioned within a common hydraulic passage having a first opening and a second opening. The control valve is positioned generally along an axis that is perpendicular to the camshaft.

Variable valve timing structure for outboard motor engine

An outboard motor incorporates a driveshaft and a propulsion shaft driven by the driveshaft. The driveshaft carries a pinion. The propulsion shaft carries forward and reverse gears. The pinion always meshes with the forward and reverse gear and drives the forward and reverse gears in opposite directions relative to each other. A hydraulic forward clutch mechanism couples the forward gear with the propulsion shaft. A hydraulic reverse clutch mechanism couples the reverse gear with the propulsion shaft. A shift actuator selectively operates the forward clutch mechanism or the reverse clutch mechanism to provide forward, reverse and/or neutral running conditions for the outboard motor.

Shift mechanism for marine propulsion unit

An engine includes an engine body that defines first and second banks arranged in a V-shape. A crankshaft extends within the engine body. First and second camshafts extend within the first bank, and third and fourth camshafts extend within the second bank. The first, second, third and fourth camshafts are generally disposed parallel to each other and parallel to the crankshaft. The first and third camshafts are placed next to each other. A first flexible transmitter surrounds the crankshaft and the first and third camshafts. The crankshaft drives the first and third camshafts through the first transmitter. A second flexible transmitter surrounds the second and fourth camshafts and either the first or third camshaft. The first or third camshaft drives the second and fourth camshafts through the second transmitter. The engine also includes VVT mechanisms to change an angular position of the camshafts relative to the crankshaft. The VVT mechanisms are disposed at the camshafts. Each VVT mechanism at least in part overlaps with either the first or second transmitter in a direction of an axis of the associated camshaft.

A marine drive has an engine, a propeller and a transmission to switch the propeller between a propulsion position and a non-propulsion position. The engine has a combustion chamber. An air induction system communicates with the combustion chamber through an intake port. An exhaust system communicates with the combustion chamber through an exhaust port. Intake and exhaust valves move between an open position and a closed position of the intake port and the exhaust port, respectively. Intake and exhaust camshafts actuate the intake and exhaust valves, respectively. A VVT mechanism changes an actuating timing of the intake camshaft at which the camshaft actuates the intake valve. An ECU controls the intake camshaft to set the actuating timing at a generally optimum timing. A transmission position change operation sensor senses that the transmission is under operation and sends a signal to the ECU. The ECU controls the VVT mechanism based upon the signal to move the actuating timing away from the optimum timing. Otherwise, a transmission position sensor senses that the transmission is in a neutral position and sends a signal to the ECU. The ECU controls the VVT mechanism based upon the signal to bring the actuating timing to a generally fully retarded timing.

An engine has a combustion chamber. An air induction system communicates with the combustion chamber through an intake port. An exhaust system communicates with the combustion chamber through an exhaust port. Intake and exhaust valves move between an opening position and a closing position of the intake port and the exhaust port, respectively. A camshaft actuates either the intake valve or the exhaust valve. The camshaft extends generally vertically. A VVT mechanism changes an angular position of the camshaft. A sensor detects the angular position and generates a signal indicative of the angular position. The sensor is disposed below the VVT mechanism.

Growing community of inventors

Shizuoka, Japan

Goichi Katayama