Honda Motor Co., Ltd.

Shohei Kono

Sei Watanabe

Hirosuke Niwa

Hayate Araki

Gaku Naoe

Hiroshi Mizuguchi

Yoshikazu Sato

Yoshikazu Yamada

Akihito Kasai

Masashi Kai

Souhei Honda

Manabu Hashimoto

Hiroko Murakami

Kotaro Sugi

Yoshinobu Kondo

Naohiro Ikeda

A V-type engine, an outboard motor, and a ship capable of restricting exposure of a catalyst to water. Cylinders where pistons operate are arranged in a V-shape, a crankshaft driven by driving of the pistons is disposed vertically, and exhaust pipes communicating with exhaust openings in the respective banks of a cylinder head and a catalyst holder that holds a catalyst in a merge portion where the exhaust pipes are merged in a site located on an upper side of the banks are included.

V-type engine, outboard motor, and ship

A V-type engine, an outboard motor, and a ship capable of restricting exposure of a catalyst to water. The engine includes cylinders where pistons operate are arranged in a V-shape, a crankshaft driven by driving of the pistons is disposed vertically, and exhaust pipes communicating with exhaust openings in the respective banks of a cylinder head and a catalyst holder that holds a catalyst in a merge portion where the exhaust pipes are merged in a site located on an upper side of the banks are included.

A V-type engine in which exhaust pipe arrangement is easily performed and purification of exhaust gas can be performed by a single catalyst. Cylinders where pistons operate are arranged in a V-shape, a crankshaft driven by the driving of the pistons is disposed vertically, exhaust pipes communicating with exhaust openings in the respective banks of a cylinder head are included, rear exhaust pipes in the respective banks are merged outside on a side of the crankshaft, and a catalyst holder that holds a catalyst is provided in a merge portion of the rear exhaust pipes. Since the rear exhaust pipes in the respective banks are merged and the catalyst holder is provided in this merge portion, exhaust gas from each bank can be purified by the single catalyst, so that the number of catalysts installed is reduced to thus be able to reduce manufacturing cost.

V-type engine, outboard motor, and watercraft

In an internal combustion engine, an oil return passage extending from a breather chamber can be formed without increasing the number of component parts and without increasing the size of the internal combustion engine. The internal combustion engine () comprises an engine block () defining a cylinder (); a case member () fastened to a lower part of the engine block to define a crank chamber jointly with the engine block; a bearing member () fastened to the engine block in the crank chamber to rotatably support a crankshaft; a breather chamber () defined in the engine block; an inlet passage () formed in the engine block to communicate the crank chamber with the breather chamber; a connection pipe () communicating the breather chamber with an intake device; and an oil return passage () formed at least in the bearing member, and extending from a bottom part of the breather chamber to an oil return port () opening at an outer surface of the bearing member. The oil return port may be provided in a lower part of the bearing member.

Internal combustion engine

Provided is an engine device that can enlarge a space inside a case without lowering support stiffness. An engine () is attached to a case () via support parts (). A rear lower portion support part (), which is one of the support parts, includes an attachment rib () as a mounting part provided in the case () and an attachment bracket () fastened to a bottom of a crankcase () by a fastening bolt () and attached to the attachment rib (). The fastening bolt () penetrates through a through hole () provided in the attachment bracket () and is screwed into a screw hole () formed obliquely inward at a corner of the bottom of the crankcase ().

Engine device

In an internal combustion engine, a breather chamber can be formed without increasing the number of component parts. The internal combustion engine () comprises an engine block () defining a cylinder (); a case member () fastened to a lower part of the engine block to define a crank chamber () jointly with the engine block; and a bearing member () fastened to the engine block in the crank chamber to rotatably support a crankshaft; wherein the engine block is provided with a central recess () formed in a part thereof to which the bearing member is fastened, a blow-by gas inlet passage () communicating the central recess with the crank chamber, and a blow-by gas return passage () forming a part of a passage communicating the central recess with an intake device, the central recess and the bearing member jointly defining a central breather chamber.

The overhead camshaft engine () includes a cylinder block (), a crankcase () attached to a lower part of the cylinder block to define a crankcase chamber (), a bearing retaining member () attached to a part of the cylinder block, a crankshaft () rotatably supported by a pair of bearings () supported by the cylinder block and the bearing retaining member, respectively, and a crankshaft pulley () attached to a part of the end of the crankshaft projecting outward from the bearing supported by the bearing retaining member.

Overhead camshaft engine

In an overhead cam engine () having a first bearing () supported by the cylinder block (), and a second bearing () supported by a bearing retaining member () attached to the cylinder block inside a crankcase chamber () for rotatably supporting a crankshaft (), the crankshaft is provided with a reduced diameter portion () having a smaller outer diameter than an adjoining part of the crankshaft on a side of the second bearing facing away from a cylinder () defined in the cylinder block, and a crankshaft pulley () is mounted on the reduced diameter portion.

An engine muffler includes a cylindrical muffler body whose interior is partitioned by at least one partition plate in a longitudinal direction of the muffler body into a plurality of expansion chambers. The muffler body is constructed of a plurality of divided muffler body members divided from each other in the longitudinal direction at the position of the partition plate, and a gap is provided between opposed end portions of the divided muffler body members. The partition plate has an annular section held in fitting engagement with the inner peripheral surface of at least one of the opposed end portions, and it is positioned in such a manner as to close the gap. The opposed end portions are welded, from a radially outward direction, to the outer peripheral surface of the annular section along their respective entire perimeters.

Engine muffler

A vertical engine includes: an oil pump provided adjacent to the lower surface of a cylinder barrel and connected to a lower end portion of a cam gear shaft to be driven by the gear shaft; a first lubricating oil passageway for supplying lubricating oil from the oil pump to a lower bearing of a crankshaft; a second lubricating oil passageway extending through the crankshaft from the lower bearing to an upper bearing of the crankshaft; a third lubricating oil passageway provided adjacent to the upper surface of the barrel and extending from the crankcase to immediately below stem end portions of intake and exhaust valves so that lubricating oil leaked from the second lubricating oil passageway flows therethrough; and a fourth lubricating oil passageway for returning lubricating oil, dripped down from the third lubricating oil passageway to the stem end portions, to the pump.

Vertical engine

A multi-link, adjustable-stroke type engine includes: a timing gear provided on and concentrically with a crankshaft; an eccentric gear provided on an eccentric shaft and meshing with the timing gear so that rotation of the timing gear is transmitted to the eccentric gear; a lubricating oil passage provided in a cylinder barrel for supplying lubricating oil to lower shaft end portions of the crankshaft and eccentric shaft; and an ejection section provided in the lubricating oil passage for ejecting lubricating oil toward a meshing engagement section between the timing gear and the eccentric gear.

Multi-link, adjustable-stroke type engine

An engine includes: a crankshaft; a camshaft; and a timing transmission systemwhich has a drive rotation member, a driven rotation member, and an endless power transmission member, and which provides connection between the crankshaftand the camshaft. An access windowthrough which the driven rotation memberis attached to and detached from the camshaftis opened in an outer end surfaceof the cylinder head. A lid bodyfor closing the access windowis jointed to the outer end surface. The outer end surfaceof the cylinder headcomprises a slanted surfacewhich is inclined so that at least a part of an outer periphery of the driven rotation memberon a side opposite from the drive rotation memberis exposed from the access window. Thus, it is possible to facilitate the operation of attaching the endless power transmission member to the driven rotation member and mounting the driven rotation member to the camshaft, and also contributing to downsizing of the engine.

Engine

In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, an oil supply hole for supplying lubricating oil to a position between a connection tubular part of a sub connecting rod and a crank pin is provided in an upper portion of the connection tubular part at a position which is deviated from a direction of application of maximum load applied from the crank pin to an inner surface of the connection tubular part by maximum in-tube pressure, and which is immediately behind a point of application of the maximum load along a direction in which the crank pin rotates relative to the sub connecting rod. Accordingly, it is possible to prevent leak of oil from the oil supply hole and thereby reliably lubricating the position between the connection tubular part of the sub connecting rod and the crank pin by a splash lubrication system.

Link type variable stroke engine

In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, a counterweight part which is provided so that in a projection view on a plane orthogonal to an axis of a rotary shaft, a center of gravity of the counterweight part is located on an opposite side of the axis of the rotary shaft from an axis of the eccentric shaft rotates together with the rotary shaft. Accordingly, it is possible to effectively suppress and lessen half-order inertial exciting force occurring at the eccentric shaft.

In a link type variable stroke engine in which a piston, a crankshaft and an eccentric shaft are linked by a linking mechanism, counterweights are provided on the crankshaft so that in a projection view on a plane orthogonal to a rotation axis of the crankshaft, centers of gravity of the counterweights are located on a straight line extending from the rotation axis of the crankshaft in an opposite direction to a direction of a total inertial exciting force when the total inertial exciting force becomes maximum, the total inertial exciting force being obtained by adding inertial exciting forces occurring respectively in movable components of the linking mechanism. Accordingly, it is possible to effectively suppress and lessen inertial exciting force.

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Wako, Japan

Shohei Kono