Abstract: Provided are a photon up-conversion film, which is capable, of high-efficiency up-conversion even in air and even when low-intensity light is used, and a simple method of producing the film. The photon up-conversion film according to one embodiment of the present invention includes: a matrix including a resin; and a pore portion, wherein the photon up-conversion film includes at least a sensitizing component capable of absorbing light in a first wavelength region ?1, and a light-emitting component capable of radiating light in a second wavelength region ?2 including wavelengths shorter than those of the first wavelength region ?1, and wherein the sensitizing component and the light-emitting component are present at an interface between the matrix and the pore portion.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 20. The lid 21 is not deformed locally, and forms a curved surface continuing from remaining portion of the cowl 20.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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 he 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.

Abstract: 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.

Abstract: 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 20. The lid 21 is not deformed locally, and forms a curved surface continuing from remaining portion of the cowl 20.

Abstract: 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.

Abstract: 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.