Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Makoto Yonezawa

Akihisa Shinoda

Takashi Suzuki

Hiroki Tawa

Hiroaki Kojima

Hiroshi Moriyama

Yasutake Ryu

Motohiro Fujita

Toru Taniguchi

Makoto Yazaki

Yoshikazu Yamada

Keiichiro Bungo

Yoshihiko Fukuda

Takeshi Inaba

Haruo Tsusaka

Hiroyuki Nakano

Hirohisa Ishikawa

Naoyuki Kamiya

Sou Abe

Fumio Ogata

Yuichi Tokito

Yoji Fujinaga

Ryoji Saiki

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

An outboard motor has an engine and a mounting case disposed below and connected to the engine. The mounting case has a depression opening upward. The opening is covered by a cover to form a coolant chamber. An exhaust passage passes through the coolant chamber and communicates with an exhaust expansion chamber formed by an extension case to be positioned below the mounting case. The coolant chamber is covered by the cover so that a small mating surface is formed with the coolant chamber independently of an engine mating surface of the mounting case. This simplifies the structure of the mounting case.

In a water-cooled multi-cylinder vertical engine for an outboard engine system, cooling water having passed through an exhaust-manifold cooling water jacket for cooling an exhaust passage within an engine room is supplied to a cylinder-block cooling water jacket provided in a cylinder block through water supply pipes, a branching member and two upper and lower couplings. In this case, the lower coupling is locked below the center of a lowermost cylinder to minimize unevenness in flow rate of the cooling water flowing through a water jacket on opposite left and right sides of a cylinder toward a cooling water outlet provided at an upper portion thereof, thereby making uniform the distribution of the temperature around a combustion chamber, leading to an enhancement in cooling effect.

Water-cooled engine

There is provided an outboard motor (), comprising: an intake valve () and an exhaust valve () provided to a cylinder head (); a camshaft () arranged substantially vertically in the cylinder head to open and close the intake and exhaust valves; a valve operation characteristics changing device () hydraulically operated to change operation characteristics of at least one of the intake and exhaust valves; a selector valve (electromagnetic valve) for controlling an oil pressure provided to the valve operation characteristics changing device; and an exhaust passage component part (exhaust manifold) secured on a side of the cylinder head, wherein the selector valve is disposed at a position (space G) beside the cylinder head and overlapping with a top end surface of the exhaust passage component part.

An outboard motor includes a water-cooled V-engine. The engine includes right and left cylinder block portions each having plural cylinders formed therein. The cylinders of each cylinder block portion are vertically juxtaposed. Cylinder heads are disposed behind the cylinder block portions. The outboard motor has horizontal and vertical shafts. The outboard motor can tilt up on the horizontal shaft and pivot sideways on the vertical shaft. The cylinders of each cylinder block portion have a cooling jacket formed therein. The lowermost cylinder has a discharge portion formed at an outermost part thereof. The discharge portion is designed to discharge out cooling water remaining in the cooling jacket.

Outboard motor including water-cooled V-engine

A V-2 engine includes two cylinder blocks mounted to a crankcase such that the respective cylinder axes of the cylinder blocks extend at an angle to each other and merge together at the axis of a crankshaft with the angle formed between the cylinder axes being divided into two angle parts by a centerline of the crankcase passing through the axis of the crankshaft, and an auxiliary machine mounted to the crankcase on the same side as one of the cylinder blocks when viewed from the axis of the crankshaft. In order to reduce the maximum width of the engine, the cylinder blocks are offset from a symmetric position with respect to the centerline of the crankcase to such an extent that a straight line circumscribing an outer end of a head cover attached to the one cylinder block and an outer end of the auxiliary machine is in parallel to the centerline of the crankcase.

V-2 engine

An overhead camshaft V-2 engine includes a single power transmitting mechanism disposed on one side of a crankcase for transmitting rotational power from a crankshaft to respective camshafts of drive valve mechanisms. The power transmitting mechanism has a driving member mounted to only one end portion of the crankshaft. The thus arranged power transmitting mechanism enables downsizing of the engine. Two intake ports are formed in respective cylinder heads of two cylinder blocks and open at one end to respective first surfaces of the cylinder heads facing in a first direction, and two exhaust ports are formed in the respective cylinder heads of the cylinder blocks and open at one end to respective second surfaces of the cylinder heads facing in a second direction opposite to the first direction. With this arrangement of the intake and exhaust ports, intake pipes can be arranged with a high degree of freedom.

Overhead camshaft V-2 engine

A lubricating and breather system is provided for use with a crankcase and a cylinder block in both a horizontal-type engine and a vertical-type engine, in which the discharge of a blow-by gas and the circulation of oil separated from the blow-by gas into the crankcase can be reliably performed. When the engine is of a vertical-type, it includes a crankcase which is disposed so that a second bearing boss is located above a first bearing boss. The second bearing boss is provided with an annular chamber into which splashed oil produced in the crankcase is passed. A breather chamber is provided in a cylinder block to communicate with the annular chamber, and includes a first return bore provided in a portion thereof which is a lowermost portion when in the horizontal-type engine, and a second return bore in a portion thereof which is a lowermost portion when in the vertical-type engine.

Lubricating and breather system in engine

A rotary disc of a speed-regulating centrifugal governor driven by a crank shaft is rotatably fitted to a crank case of an engine. While part of the rotary disc is immersed in lubricating oil stored in the crank case, the rotary disc is disposed adjacent to a timing gear and impeller blades project from the outer peripheral face of the rotary disc so as to form an impeller. Further, guide walls for guiding oil splashed by the rotation of the impeller to the timing gear are integrally formed with the inside wall of the crank case, so that the timing gear of a valve mechanism can be effectively lubricated with the splashed oil.

Valve mechanism lubricator of engine

An OHC vertical crankshaft engine, comprising: a vertically disposed crankshaft having a first timing pulley at its lower end; a cooling fan attached to an upper end of the crankshaft; a camshaft extending in parallel with the crankshaft at a cylinder head end of the engine and having a second timing pulley at its lower end; and a timing belt passed around the timing pulleys. Thus, the need for lubrication for the transmission mechanism between the crankshaft and the camshaft is substantially eliminated, and the noise generation is reduced. Additionally, since the upper part of the cylinder head is directly exposed to the cooling air produced by a fan provided at an upper end of the crankshaft, a high engine cooling efficiency can be achieved. This effect is even more enhanced if the exhaust port of the engine is disposed above the intake port and extends horizontally and linearly away from the engine.

OHC vertical crankshaft engine

A liquid cooled internal combustion engine, comprising: an integrally cast engine main body including a cylinder block, a cylinder head, and a crankcase skirt, a crankcase cover attached to an open end of the skirt to define a crankcase therein, a crankshaft extending vertically in the crankcase and rotatably supported by the skirt at its both ends, a camshaft rotatably supported by the cylinder head and extending in parallel with the crankshaft, a timing belt passed around pulleys mounted on lower ends of the camshaft and the crankshaft, respectively, and extending in a belt chamber defined in the cylinder block along a lower side of the cylinder bore; a cooling liquid jacket defined in the cylinder block along upper and lateral sides of the cylinder bore. The jacket may be formed during the casting process by pulling a core either upwards or toward the open end of the skirt. The cooling liquid may consist of the lubricating oil for the engine. Thus, a jacket for the cooling liquid can be formed without requiring its cylinder head to be cast separately from its cylinder block, and the rigidity of the part of the cylinder block adjoining its cylinder head can be increased without increasing its wall thickness. Also, a compact design of the engine is made possible, and the process of fabricating the engine can be simplified.

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Wako, Japan

Makoto Yonezawa