Abstract: A direct fuel-injection engine includes a piston, a cavity recessed in a central part of a top face of the piston, and a fuel injector. At a main injection collision point of a fuel-injection axis when main injection is performed while the piston is near top dead center, a main injection collision angle formed between its tangent and the fuel-injection axis is set at an obtuse angle. Fuel colliding with the main injection collision point is deflected towards a cavity open end side. At a secondary injection collision point of the fuel-injection axis when performing secondary injection with the piston is further from top dead center, a secondary injection collision angle formed between its tangent and the fuel-injection axis is set at one of a right angle and an acute angle. Fuel colliding with the secondary injection collision point is deflected primarily in the circumferential direction of the cavity.

Abstract: A battery cooling structure is provided in which since a battery support member (43) that is disposed above a lower layer battery group (B4, B5) and supports an upper layer battery group (B6) on its upper face is formed so as to be hollow, and the upper layer battery group (B6) is cooled by a cooling medium that flows in an interior of the battery support member (43), due to the battery support member (43) having the dual function of supporting the upper layer battery group (B6) and cooling the upper layer battery group (B6), it is possible to cut the number of components and simplify the structure. Moreover, since the cooling medium flows in the interior of the battery support member (43) and does not come into direct contact with the upper layer battery group (B6), the upper layer battery group (B6) is not contaminated by the cooling medium.

Abstract: In an internal combustion engine having a pair of balancer shafts (53, 54), an engine torque is transmitted from a crank gear (28) to an oil pump gear (74) on a drive shaft (73) of an oil pump (71) via a first idler gear (84) and the first balancer shaft gear (64). The engine torque is also transmitted to a fuel pump (72) from the crank gear to a fuel pump gear (78) via the first idler gear and a second idler gear (86), and to the second balancer shaft gear (67) via the first idler gear and second idler gear. Alternatively, the engine torque may be transmitted to the fuel pump from the crank gear to the fuel pump gear via the first idler gear, second balancer shaft gear and second idler gear. As the oil pump gear is actuated by the crank gear via the first idler gear, the oil pump gear is not subjected to the loading caused by the balancer shaft, and hence can be made of a compact and light-weight gear.

Abstract: A battery cooling structure includes a first battery group, a second battery group, a third battery group, a first duct, a second duct, a third duct, a fourth duct, a fifth duct, a first connecting duct, a second connecting duct, a third connecting duct, and a bypass duct. The first duct is configured to allow a cooling medium after heat exchange to flow through the first duct. The second duct is configured to allow a cooling medium after heat exchange to flow through the second duct. The fifth duct is configured to allow a cooling medium after heat exchange to flow through the fifth duct. The bypass duct connects the fifth duct to the second duct or to the first duct.

Abstract: In an internal combustion engine having a pair of balancer shafts (53, 54), an engine torque is transmitted from a crank gear (28) to an oil pump gear (74) on a drive shaft (73) of an oil pump (71) via a first idler gear (84) and the first balancer shaft gear (64). The engine torque is also transmitted to a fuel pump (72) from the crank gear to a fuel pump gear (78) via the first idler gear and a second idler gear (86), and to the second balancer shaft gear (67) via the first idler gear and second idler gear. Alternatively, the engine torque may be transmitted to the fuel pump from the crank gear to the fuel pump gear via the first idler gear, second balancer shaft gear and second idler gear. As the oil pump gear is actuated by the crank gear via the first idler gear, the oil pump gear is not subjected to the loading caused by the balancer shaft, and hence can be made of a compact and light-weight gear.

Abstract: In a direct fuel-injection engine equipped with a pentroof-shaped piston, cross-sectional shapes containing a piston central axis (Lp) of a cavity recessed in a central part of the piston having a top face with the height varying in the circumferential direction are set so as to be basically identical at each position in the circumferential direction (see broken line).

Abstract: A direct fuel-injection engine includes a piston, a cavity recessed in a central part of a top face of the piston, and a fuel injector. At a main injection collision point of a fuel-injection axis when main injection is performed while the piston is near top dead center, a main injection collision angle formed between its tangent and the fuel-injection axis is set at an obtuse angle. Fuel colliding with the main injection collision point is deflected towards a cavity open end side. At a secondary injection collision point of the fuel-injection axis when performing secondary injection with the piston is further from top dead center, a secondary injection collision angle formed between its tangent and the fuel-injection axis is set at one of a right angle and an acute angle. Fuel colliding with the secondary injection collision point is deflected primarily in the circumferential direction of the cavity.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.