Honda Giken Kogyo Kabushiki Kaisha

Honda Motor Co., Ltd.

Nissan Motor Company Limited

Minoru Matsuda

Makoto Sanada

Kentaro Kato

Kazuo Inoue

Takashi Shinozaki

Shumpei Hasegawa

Kazuto Fukuzawa

Masatoshi Suzuki

Daisuke Hayashi

Mitsuo Nakagawa

Junji Otani

Masanori Masumura

Atsushi Niimi

Kazuhiro Uehara

Mamoru Mikame

Toshiro Mitsuishi

Toshimitsu Yoshimura

Yoji Kitahara

Tadashi Muraishi

Kenzo Kaji

Tsuneaki Arakawa

To reduce the number of parts, improve the mountability and maintainability, and allow for a reduction in the size and weight an engine is provided having a crankshaft, a crankcase having a plurality of bearing portions for rotatably supporting the crankshaft with each of the bearing portions being dividable along a divisional plane arranged on the axis of the crankshaft. Cylinder barrels are connected to the crankcase and include cylinder bores with cylinder heads connected to the cylinder barrels. The cylinder heads are integrated with portions of the cylinder barrels forming at least the cylinder bores to form cylinder blocks. The cylinder blocks and the crankcase are fastened together by a plurality of fastening bolts having axes parallel to the axes of the cylinder bores and extending through at least the cylinder blocks, with a compressive structure in the axial direction of the fastening bolts.

Engine

To simplify a coolant piping around an engine in an engine cooling structure, which has a pump mounted on a crankcase for circulating a coolant between cylinder and head jackets. A crankcase has coolant supply passages for guiding a coolant from a pump and coolant return passages for guiding a coolant delivered out of cylinder jackets. The coolant supply passages and the coolant return passages extend substantially parallel to the axis of a crankshaft. The cylinder jackets and head jackets are formed wherein the coolant supplied from the coolant supply passages returns from the cylinder jackets via the head jackets to the cylinder jackets.

Engine cooling structure

In a multi-cylinder engine, a decrease of the load capacity of a main metal bearing between a bearing portion of a crankcase and a crank journal is prevented to achieve a reduction in the scale and a reduction in the weight of the engine while lubricating oil is supplied between a major end portion of a connecting rod and a crankpin. A pair of outermost crank journals are disposed most outwardly along an axial line of a crankshaft from among a plurality of crank journals have a length in the axial direction set greater than the length of the remaining crank journals in the axial direction. Crankpin oil paths extending from at least one of the two outermost crank journals to the crankpins are provided in the crankshaft while an oil supply source is connected to the crankpin oil paths at least at one of the outermost crank journals.

Multi-cylinder engine

To simplify the connection of a cylinder barrel and a cylinder head to, a crankcase and to reduce the weight of an engine. A liquid-cooled engine is provided with the crankcase wherein a cylinder barrel having a water jacket on the cylinder side for cooling is connected to the crankcase. A cylinder head is connected to the cylinder barrel. A plurality of mounting bosses extend from fitting planes to a crankcase of the cylinder barrels and to cylinder heads that are integrated with cylinder blocks. The cylinder barrels and the cylinder heads are integrated in a state in which the mounting bosses encircle the cylinder bores and the cylinder blocks are fastened to the crankcase by bolts inserted into each mounting boss.

Liquid-cooled engine

The lower end of a filler tube is attached to a service hole formed on a cylinder block in a horizontally opposed engine on a rear side of the engine, e.g., on side opposite from which an output shaft projects. The filler tube is provided with an elbow at the lower end thereof, and the elbow is integrally formed with a hole cover. When one end of the elbow is inserted into the service hole and the hole cover is fixed to the cylinder block, the connection of the filler tube and closing of the service hole can be simultaneously accomplished. The filler tube extends upward and a cap is attached on the filler port at the upper end facing toward the vicinity of the lid provided on the cowl. The lidis not deformed locally, and forms a curved surface continuing from remaining portion of the cowl

Lubricating oil filling structure for an engine

To attain downsizing and weight reduction of a starter motor and starting power transmission in an engine starting apparatus. The starting power transmission decelerates rotation power of the starter motor and transmits the power to a crankshaft, even in a multi-cylinder engine. The starting power transmission is provided between the starter motor that starts rotation by electric power supplied from a battery and the crankshaft. An exhaust valve is depressed and opened by actuation of an actuator in accordance with actuation of the starter motor. The actuation of the actuator is continued until the number of revolutions of the crankshaft detected by a revolution detector reaches a predetermined number of revolutions.

Engine starting apparatus

To reduce the size and weight of an engine body and improve the mountability and maintainability of transmitting rods in a valve train for an OHV engine having a crankshaft, a crankcase for rotatably supporting the crankshaft, a camshaft incorporated in the crankcase, cylinder heads connected to the crankcase, engine valves operably provided in the cylinder heads, and the transmitting rods for transmitting a valve operating force due to the rotation of the camshaft to the engine valves. The transmitting rods as pull rods are arranged on one side of cylinder barrels. One end portion of each transmitting rod is formed with an engaging portion disengageably engaged with a hook portion of a mating member. An engine body or a guide member, fixed to the engine body, is provided with a guide portion for guiding the engaging portion to the hook portion of the mating member.

Valve train for OHV engine

A plug cap guide for enhancing the reliability of mounting a plug cap to a rear portion of a spark plug. The plug cap guide is formed in a hollow cylindrical shape so as to contain a plug cap therein and to have a tip end portion insertable in a plug hole. The plug cap guide is provided with a pressing portion for pressing the plug cap toward the side of a spark plug. A positioning and fixing element for determining the position in the axial direction of the plug cap guide and fixing the plug cap guide is provided between a rear portion of the plug cap guide and a head cover.

Plug cap mount structure for engine

In a valve system for a OHV horizontally-opposed, four-cycle internal combustion engine, valve camshafts are provided at crankcase portions for supporting a crankshaft, of left and right cylinder banks disposed on opposite sides of the crankshaft. Intake and exhaust valves are provided at cylinder heads and are opened and closed by pull rods operated by the valve camshafts. The aforementioned valve system achieves large reductions in the size and weight of the piston heads where the intake and exhaust valves of the internal combustion engine are disposed.

Valve system for OHV-type four-cylinder internal combustion engine

To provide a four-cycle engine, in which a pair of intake valve ports is openable/closable by respective intake valves and a pair of exhaust valve ports is openable/closable by respective exhaust valves. The pair of intake valve ports and the pair of exhaust valve ports are provided in a cylinder head such that they are positioned on both sides of a first virtual plane which contains the axial line of the cylinder bore and passes through an approximately central portion of the combustion chamber. A pair of ignition plugs is mounted in the cylinder head. The pair of ignition plugs is mounted such that the degradation of a flame propagation condition is minimized, even if accidental firing of either of the ignition plugs occurs. The pair of ignition plugs is disposed substantially symmetrically with respect to a second virtual plane which passes through the center of a combustion chamber and is perpendicular to the first virtual plane. The ignition plugs are mounted in the cylinder head such that they have axial lines extending substantially in parallel to the first virtual plane. The ignition plugs are tilted with a distance therebetween becoming smaller toward the combustion chamber. End portions of the ignition plugs, which project into the combustion chamber, are disposed in a region surrounded by the intake valve ports and the exhaust valve ports.

Four-cycle engine

To provide an oil pump mounting structure for an engine. The engine includes a crankcase rotatably supporting a crankshaft, an oil pan connected to a lower portion of the crankcase, and an oil pump interlocked for rotation with the crankshaft. The oil pump mounting structure lowers the center of gravity of the engine and improves the suction efficiency and maintenance characteristic of the oil pump. A pump housing of the oil pump is removably mounted on a mounting portion provided on the bottom of an oil pan.

Oil pump mounting structure for engine

To provide a valve system for an engine, in which a rocker arm is interlocked with an engine valve and is supported on a rocker shaft fixedly mounted to a cylinder head such that it is rockable with the rotation of a camshaft. Accordingly, the size and weight of the engine can be reduced. The posture of a rocker shaft is set to have an axial line crossing an axial line of a crankshaft on the projection plane perpendicular to an axial line of a cylinder bore. A rocker arm is rockably supported by the rocker shaft and is provided with an input arm extending, on the above projection plane, from the rocker arm to the camshaft side. A pull rod reciprocates in the axial direction with the rotation of the camshaft and is connected to the input arm.

Valve system for engine

In a horizontally opposed type internal combustion engine, to enable rigid support of a middle journal of a crankshaft through rational utilization of first and second case halves constituting a crankcase, and to thereby contribute to a simplification in structure and a reduction in weight. In a horizontally opposed type internal combustion engine, a crankcase is split at a plane containing the axis line of a crankshaft into first and second case halves connected with first and second cylinder blocks. The first and second case halves are integrally provided with first and second journal supporting walls for supporting a middle journal of the crankshaft. The first and second journal supporting walls front cylinder bores of the first and second cylinder blocks. The first and second journal supporting walls are coupled by a plurality of first bolts inserted from the side of the cylinder bores of the first cylinder block and disposed on opposite sides of and in proximity to the middle journal.

Crankshaft supporting structure for horizontal opposed type internal combustion engine

An intake system for a horizontally opposed type internal combustion engine can contribute to an improvement in output performance without sacrificing the intrinsic merit of the horizontally opposed type internal combustion engine. Specifically, the intake system ensures that the overall height of the engine remains small. First and second intake ports are provided at head portions of first and second banks, which are arranged on the left and right sides. First and second intake distribution ports are arranged horizontally at a front wall of an intake surge tank , which is disposed on the rear end side of and adjacent to a crankshaft . The first and second intake ports are respectively connected with each other through first and second intake pipes disposed along a top surface or bottom surface of the engine E. Throttle valves for controlling intake quantities in the first and second intake pipes are provided in upstream portions of the intake pipes.

Intake system for horizontal opposed type internal combustion engine

To provide a valve system for an engine, in which a valve stem for an engine valve is slidably fitted in a guide cylinder provided in a cylinder head. A rocker arm is interlocked to rock with rotation of a camshaft. The rocker arm is also interlocked with the valve stem. With the above construction, local wear, galling, and the like in the guide cylinder can be prevented. Accordingly, the reliability can be improved. A lifter is interposed between a rocker arm and a valve stem. The lifter is formed into a cylindrical shape with a closed bottom and has a diameter larger than an outside diameter of the valve stem. The lifter is fitted in a lifter housing in such a manner as to be slidable in the axial direction of the valve stem. The lifter housing is fixed to a cylinder head.

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Saitama, Japan

Minoru Matsuda