Abstract: A motorcycle is provided in which a seat and a storage box are arranged so as to be vertically stacked on each other in a rear portion of a body frame, and a pivotally mounted powertrain unit is suspended from the body frame under the storage box. The powertrain unit extends in the fore-and-aft direction of the body frame, and the engine has a crank chamber and a lubricant oil chamber provided separately from each other. A lubrication-oil passage structure for the engine is provided between each of a pair of journal bearing portions of a crankcase. The crankcase has an enclosed crank chamber and a crankshaft which is freely rotatably supported by the journal bearing portions with plain bearings. The journal bearing portions are provided with protrusion bosses for resisting entry of lubricating oil into the crank chamber from outside of the crankcase.

Abstract: A motorcycle is provided in which a seat and a storage box are arranged so as to be vertically stacked on each other in a rear portion of a body frame, and a pivotally mounted powertrain unit is suspended from the body frame under the storage box. The powertrain unit extends in the fore-and-aft direction of the body frame, and the engine has a crank chamber and a lubricant oil chamber provided separately from each other. A lubrication-oil passage structure for the engine is provided between each of a pair of journal bearing portions of a crankcase. The crankcase has an enclosed crank chamber and a crankshaft which is freely rotatably supported by the journal bearing portions with plain bearings. The journal bearing portions are provided with protrusion bosses for resisting entry of lubricating oil into the crank chamber from outside of the crankcase.

Abstract: A vehicle radiator device having a radiator with a first tank and a second tank coupled through a heat radiation core. The radiator is mounted onto an engine in a power unit supported by a vehicle body frame. The first and second tanks of the radiator are made of synthetic resin. The radiator is mounted onto the engine through a shroud for conducting cooling wind passing through the radiator. The shroud is made of elastic material for conducting cooling so that vibrations of the engine are absorbed by the elasticity of the shroud, thus preventing vibration of the radiator.

Abstract: There is provided an economical carburizing method and carburization apparatus capable of carrying out carburizing treatment with a quality as high as that in a normal case and a high reproducibility even if carburizing conditions differ from those in a normal case. A carburization apparatus for carrying out carburization in an atmosphere gas containing not more than 30% by volume of carbon monoxide under a pressure of 13 to 4,000 Pa has a carburizing chamber 3 for housing an object 4 to be treated; an oxygen sensor 20 for measuring an oxygen concentration in the atmosphere gas in the carburizing chamber 3 during carburization; and a mass flow controller 5 for adjusting a composition of the atmosphere gas in the carburizing chamber 3 according to a measurement result by the oxygen sensor 20.

Abstract: In a magnet force type pump driving apparatus in a vehicular engine, a large diameter formation of driving and driven magnets is enabled without being interfered with by a driven rotating member of a wrapping transmission apparatus, thereby achieving an increase in transmission torque. A magnet holder crossing a rotational center face P of a wrapping member of a wrapping transmission apparatus is fixedly attached to a driven rotating member. A driving magnet is arranged at an outer side of the driven rotating member and is attached to the magnet holder. A driven magnet is axially supported by a pump housing arranged to cross the rotational center face P on an inner peripheral side of the driving magnet.

Abstract: There is provided an economical carburizing method and carburization apparatus capable of carrying out carburizing treatment with a quality as high as that in a normal case and a high reproducibility even if carburizing conditions differ from those in a normal case. A carburization apparatus for carrying out carburization in an atmosphere gas containing not more than 30% by volume of carbon monoxide under a pressure of 13 to 4,000 Pa has a carburizing chamber 3 for housing an object 4 to be treated; an oxygen sensor 20 for measuring an oxygen concentration in the atmosphere gas in the carburizing chamber 3 during carburization; and a mass flow controller 5 for adjusting a composition of the atmosphere gas in the carburizing chamber 3 according to a measurement result by the oxygen sensor 20.

Abstract: A vehicle radiator device having a radiator with a first tank and a second tank coupled through a heat radiation core. The radiator is mounted onto an engine in a power unit supported by a vehicle body frame. The first and second tanks of the radiator are made of synthetic resin. The radiator is mounted onto the engine through a shroud made of elastic material for conducting cooling wind of the radiator in such a manner that vibrations of the engine are absorbed by the elasticity of the shroud to thereby prevent excitation to the radiator. The resulting radiator device is a simple, low-priced structure with reduced weight, which is supported by the engine in such a manner as to isolate vibrations.

Abstract: In a magnet force type pump driving apparatus in a vehicular engine, to enable large diameter formation of driving and driven magnets without being interfered with by a driven rotating member of a wrapping transmission apparatus to thereby achieve an increase in transmission torque. A magnet holder crossing a rotational center face P of a wrapping member of a wrapping transmission apparatus is fixedly attached to a driven rotating member. A driving magnet is arranged at an outer side of the driven rotating member and is attached to the magnet holder. A driven magnet is axially supported by a pump housing arranged to cross the rotational center face P on an inner peripheral side of the driving magnet.

Abstract: A lubricating system for an engine comprises an oil pan for storing a lubricating oil therein, an oil cooler for cooling the lubricating oil, and an oil pump including first and second pump rotors contained in a casing. The oil pump is provided with a suction port commonly used for both the pump rotors, a first discharge port exclusively used for the first pump rotor and a second discharge port exclusively used for the second pump rotor. The suction port is in communication with the subsurface of the oil in the oil pan, the first discharge port communicating with an inlet port of the oil cooler, and said second discharge port communicating with the to-be-lubricated portions of an engine.