Honda Motor Co., Ltd.

Takeshi Inaba

Hideaki Shimamura

Kazuhiro Ishizaka

Mitsuaki Kubota

Hikaru Ikeda

Yoshio Ohtomo

Hiroshi Yamamoto

Makoto Yazaki

Masanori Tsubouchi

Makoto Yonezawa

Nobuo Suzuki

Toru Kimura

An exhaust fan chamber is defined with a belt cover and a fan cover provided over the belt cover, and an exhaust fan is accommodated in the exhaust fan chamber. The fan cover has an air intake port for sucking air within an engine cover into the exhaust fan chamber and an exhaust outlet port for discharging air within the exhaust fan chamber to outside of the exhaust fan chamber. The exhaust outlet port is in communication with an exhaust opening formed in an upper portion of the engine cover so that the air discharged through the exhaust outlet port is discharged to outside of the engine cover through the exhaust opening.

Outboard engine unit

In an apparatus for controlling a speed of an internal combustion engine installed in an outboard motor and having an actuator connected to a throttle valve of the engine to open and close the throttle valve, and up/down command signal outputting devices that output an up/down command signal to increase/decrease the engine speed when manipulated by an operator, the engine speed is controlled to change in response to the up or down command signal with an engine speed change amount per unit time made different depending on whether the detected engine speed exceeds a reference speed or not, thereby enabling to finely and precisely control the engine speed in the low speed range, while facilitating speed regulation.

Engine speed control apparatus for outboard motor

An outboard motor S has an upstream intake silencer with an upstream expansion chamber, and a downstream intake silencer disposed under the upstream intake silencer. The upstream expansion chamber has a lower wall of a stepped shape including a raised part overlapping the downstream intake silencer in a plane and a lowered part without overlapping with the downstream intake silencer in a plane and at a level lower than that of the raised part. An upstream outlet passage of the upstream intake silencer is formed in the raised part. The downstream intake silencer has a stepped upper wall having a raised part, and a lowered part underlying the lower wall of the upstream expansion chamber in a plane and extending at a level lower than that of the raised part.

Outboard motor

In an outboard marine motor including an upper case () enclosing an engine (E) and a lower case () fitted with a propeller () and connected to a lower end of the upper case, the lower case is configured to be turned relative to the upper case around a vertical axial line. The power of the engine is transmitted to the propeller via a vertical drive shaft () which is coaxial with the vertical axial line. Thereby, the outboard marine motor can be steered simply by turning the lower case. Because the upper case having a relatively large lateral dimension as compared with the lower case is not required to be turned, a large steering angle can be achieved without the outboard marine motor interfering with watercraft having the outboard marine motor mounted thereon. This is particularly beneficial when two or more outboard marine motors are used one next to the other.

Outboard marine motor that allows a large steering angle

In an outboard marine motor including an upper case () enclosing an engine (E) and a lower case () fitted with a propeller () and connected to a lower end of the upper case, the lower case is configured to be turned relative to the upper case around a vertical axial line which is coaxial with a vertical drive shaft () that transmit torque of the engine to the propeller. Thereby, the outboard marine motor can be steered simply by turning the lower case. Because the upper case having a relatively large lateral dimension as compared with the lower case is not required to be turned, a large steering angle can be achieved without the outboard marine motor interfering with watercraft having the outboard marine motor mounted thereon. In particular, the lower case is turned by an actuator including an electric motor and a worm gear mechanism () for transmitting an output torque of the electric motor to the lower case so that a high speed reduction ratio can be achieved by using a highly compact structure.

In a propulsion device for a marine motor, a shift rod () extends vertically in a gear case () provided in a lower part of the marine motor, and is provided with a lower end () cooperating with a mechanism for mechanically actuating a clutch device () for shifting a power transmission mechanism of the propulsion device. The lower end of the shift rod is additionally provided with a valve () that controls feeding of hydraulic oil to an actuator () for assisting an effort required to turn the shift rod and actuate the clutch device. Thereby, the manual torque applied to the shift rod to turn the same to a forward and reverse position is assisted by the hydraulic actuator with a minimum modification to a purely manual arrangement for shifting the power transmission mechanism.

Propulsion device for a marine motor

An outboard motor has a top cover extending over an engine cover covering an engine, and an upstream intake silencer spaced upward apart from the top wall of the engine cover. The upstream intake silencer has an entrance duct spaced apart from the top wall and forming an inlet air passage through which air for combustion flows from an air-intake space into the upstream intake silencer. The upstream end of the inlet air passage is on the rear side of the downstream end of an outlet air passage and at a level above that of an air-intake opening. The entrance duct does not extend downward from a bottom wall forming the upstream expansion chamber and protrudes upward from the bottom wall in the upstream expansion chamber.

An operating handle of an outboard motor is provided with a rotatable grip and a low-speed mode switch unit. A controller performs control so that when the low-speed mode switch unit is 'on,' the ratio at which the target speed varies with the manipulated variable of the grip is reduced in comparison with when the low-speed mode switch unit is 'off.'

An outboard engine unit includes a single lubricating oil supply tube for supplying lubricating oil to a valve-operating chain. The valve-operating chain is suspended across a drive sprocket provided to a crankshaft and a driven sprocket provided to a camshaft. A supply tube is connected to a main gallery that is linked to a main oil channel positioned in an area adjacent to the crankshaft.

A lubrication device for an engine, includes: an oil pan which is disposed at a lower portion of an engine and stores lubrication oil; an oil pump which is disposed above the oil pan and driven by the engine; a suction oil passage which guides the oil in the oil pan to a suction port of the oil pump; and a supply oil passage which guides the oil discharged from a discharge port of the oil pump to lubrication parts of the engine. The suction oil passage is divided into an upstream oil passage on a side of the oil pan and a downstream oil passage on a side of the oil pump. A filter net serving as a strainer is sandwiched between the upstream oil passage and the downstream oil passage. Thus, it is possible to provide the light and simply-structured lubrication device for an engine.

Lubrication device for engine and outboard engine system

An outboard engine unit having heat-generating electrical equipment. An intake port of an intake silencer is set at a distance from an engine, and air suctioned from the intake port is unlikely to be affected by heat produced by the engine. Electrical equipment is disposed in a direction of opening of the intake port, and air around the electrical equipment thereby circulates when air is suctioned from the intake port.

Growing community of inventors

Wako, Japan

Takeshi Inaba